Progress in basic research, starting with the work on neural stem cells in the middle 1990's to embryonic stem (ES) cells and induced pluripotent stem (iPS) cells at present, will lead the cell therapy (regenerative medicine) of various organs, including the central nervous system to a big medical field in the future. The author's group transplanted iPS cell-derived retinal pigment epithelial (RPE) cell sheets to the eye of a patient with exudative age-related macular degeneration (AMD) in 2014 as a clinical research. Replacement of the RPE with the patient's own iPS cell-derived young healthy cell sheet will be one new radical treatment of AMD that is caused by cellular senescence of RPE cells. Since it was the first clinical study using iPS cell-derived cells, the primary endpoint was safety judged by the outcome one year after surgery. The safety of the cell sheet has been confirmed by repeated tumorigenisity tests using immunodeficient mice, as well as purity of the cells, karyotype and genetic analysis. It is, however, also necessary to prove the safety by clinical studies. Following this start, a good strategy considering cost and benefit is needed to make regenerative medicine a standard treatment in the future. Scientifically, the best choice is the autologous RPE cell sheet, but autologous cell are expensive and sheet transplantation involves a risky part of surgical procedure. We should consider human leukocyte antigen (HLA) matched allogeneic transplantation using the HLA 6 loci homozyous iPS cell stock that Prof. Yamanaka of Kyoto University is working on. As the required forms of donor cells will be different depending on types and stages of the target diseases, regenerative medicine will be accomplished in a totally different manner from the present small molecule drugs. Proof of concept (POC) of photoreceptor transplantation in mouse is close to being accomplished using iPS cell-derived photoreceptor cells. The shortest possible course for treatment is now being investigated in preclinical research. Among the mixture of rod and cone photoreceptors in the donor cells, the percentage of cone photoreceptors is still low. Donor cells with more. cone photoreceptors will be needed. If that will work well, photoreceptor transplantation will be the first example of neural network reconstruction in the central nervous system. These efforts will reach to variety of retinal cell transplantations in the future.

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3.1 Introduction

Figure 3.1 Schematic dorsal and lateral view of the spinal cord and four cross sections from cervical, thoracic, lumbar and sacral levels, respectively.

The spinal cord is the most important structure between the body and the brain. The spinal cord extends from the foramen magnum where it is continuous with the medulla to the level of the first or second lumbar vertebrae. It is a vital link between the brain and the body, and from the body to the brain. The spinal cord is 40 to 50 cm long and 1 cm to 1.5 cm in diameter. Two consecutive rows of nerve roots emerge on each of its sides. These nerve roots join distally to form 31 pairs of spinal nerves. The spinal cord is a cylindrical structure of nervous tissue composed of white and gray matter, is uniformly organized and is divided into four regions: cervical (C), thoracic (T), lumbar (L) and sacral (S), (Figure 3.1), each of which is comprised of several segments. The spinal nerve contains motor and sensory nerve fibers to and from all parts of the body. Each spinal cord segment innervates a dermatome (see below and Figure 3.5).

3.2 General Features

Although the spinal cord constitutes only about 2% of the central nervous system (CNS), its functions are vital. Knowledge of spinal cord functional anatomy makes it possible to diagnose the nature and location of cord damage and many cord diseases.

3.3 Segmental and Longitudinal Organization

The spinal cord is divided into four different regions: the cervical, thoracic, lumbar and sacral regions (Figure 3.1). The different cord regions can be visually distinguished from one another. Two enlargements of the spinal cord can be visualized: The cervical enlargement, which extends between C3 to T1; and the lumbar enlargements which extends between L1 to S2 (Figure 3.1).

The cord is segmentally organized. There are 31 segments, defined by 31 pairs of nerves exiting the cord. These nerves are divided into 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal nerve (Figure 3.2). Dorsal and ventral roots enter and leave the vertebral column respectively through intervertebral foramen at the vertebral segments corresponding to the spinal segment.

Figure 3.2 Drawing of the 8, 12, 5, 5 and 1 cervical, thoracic, lumbar, sacral and coccygeal spinal nerves and their exit from the vertebrate, respectively.

The cord is sheathed in the same three meninges as is the brain: the pia, arachnoid and dura. The dura is the tough outer sheath, the arachnoid lies beneath it, and the pia closely adheres to the surface of the cord (Figure 3.3). The spinal cord is attached to the dura by a series of lateral denticulate ligaments emanating from the pial folds.

Figure 3.3 The three spinal cord meninges. The denticulate ligament, the dorsal root ganglion (A), and an enlarged drawing of the meninges (B).

During the initial third month of embryonic development, the spinal cord extends the entire length of the vertebral canal and both grow at about the same rate. As development continues, the body and the vertebral column continue to grow at a much greater rate than the spinal cord proper. This results in displacement of the lower parts of the spinal cord with relation to the vertebrae column. The outcome of this uneven growth is that the adult spinal cord extends to the level of the first or second lumbar vertebrae, and the nerves grow to exit through the same intervertebral foramina as they did during embryonic development. This growth of the nerve roots occurring within the vertebral canal, results in the lumbar, sacral, and coccygeal roots extending to their appropriate vertebral levels (Figure 3.2).

All spinal nerves, except the first, exit below their corresponding vertebrae. In the cervical segments, there are 7 cervical vertebrae and 8 cervical nerves (Figure 3.2). C1-C7 nerves exit above their vertebrae whereas the C8 nerve exits below the C7 vertebra. It leaves between the C7 vertebra and the first thoracic vertebra. Therefore, each subsequent nerve leaves the cord below the corresponding vertebra. In the thoracic and upper lumbar regions, the difference between the vertebrae and cord level is three segments. Therefore, the root filaments of spinal cord segments have to travel longer distances to reach the corresponding intervertebral foramen from which the spinal nerves emerge. The lumbosacral roots are known as the cauda equina (Figure 3.2).

Each spinal nerve is composed of nerve fibers that are related to the region of the muscles and skin that develops from one body somite (segment). A spinal segment is defined by dorsal roots entering and ventral roots exiting the cord, (i.e., a spinal cord section that gives rise to one spinal nerve is considered as a segment.) (Figure 3.4).

Figure 3.4 (A) Drawing of the spinal cord with its spinal roots. (B) Drawing of the spinal vertebrate. (C) Section of the spinal cord, its meninges and the dorsal and ventral roots of three segments.

A dermatome is an area of skin supplied by peripheral nerve fibers originating from a single dorsal root ganglion. If a nerve is cut, one loses sensation from that dermatome. Because each segment of the cord innervates a different region of the body, dermatomes can be precisely mapped on the body surface, and loss of sensation in a dermatome can indicate the exact level of spinal cord damage in clinical assessment of injury (Figure 3.5). It is important to consider that there is some overlap between neighboring dermatomes. Because sensory information from the body is relayed to the CNS through the dorsal roots, the axons originating from dorsal root ganglion cells are classified as primary sensory afferents, and the dorsal root's neurons are the first order (1) sensory neuron. Most axons in the ventral roots arise from motor neurons in the ventral horn of the spinal cord and innervate skeletal muscle. Others arise from the lateral horn and synapse on autonomic ganglia that innervate visceral organs. The ventral root axons join with the peripheral processes of the dorsal root ganglion cells to form mixed afferent and efferent spinal nerves, which merge to form peripheral nerves. Knowledge of the segmental innervation of the cutaneous area and the muscles is essential to diagnose the site of an injury.

Figure 3.5 Innervation arising from single dorsal root ganglion supplied specific skin area (a dermatome). The numbers refer to the spinal segments by which each nerve is named C = cervical; T = thoracic; L = lumbar; S = sacral spinal cord segments (dermatome).

3.4 Internal Structure of the Spinal Cord

A transverse section of the adult spinal cord shows white matter in the periphery, gray matter inside, and a tiny central canal filled with CSF at its center. Surrounding the canal is a single layer of cells, the ependymal layer. Surrounding the ependymal layer is the gray matter a region containing cell bodies shaped like the letter H or a butterfly. The two wings of the butterfly are connected across the midline by the dorsal gray commissure and below the white commissure (Figure 3.6). The shape and size of the gray matter varies according to spinal cord level. At the lower levels, the ratio between gray matter and white matter is greater than in higher levels, mainly because lower levels contain less ascending and descending nerve fibers. (Figure 3.1 and Figure 3.6).

Figure 3.6 Spinal cord section showing the white and the gray matter in four spinal cord levels.

The gray matter mainly contains the cell bodies of neurons and glia and is divided into four main columns: dorsal horn, intermediate column, lateral horn and ventral horn column. (Figure 3.6).

The dorsal horn is found at all spinal cord levels and is comprised of sensory nuclei that receive and process incoming somatosensory information. From there, ascending projections emerge to transmit the sensory information to the midbrain and diencephalon. The intermediate column and the lateral horn comprise autonomic neurons innervating visceral and pelvic organs. The ventral horn comprises motor neurons that innervate skeletal muscle.

At all the levels of the spinal cord, nerve cells in the gray substance are multipolar, varying much in their morphology. Many of them are Golgi type I and Golgi type II nerve cells. The axons of Golgi type I are long and pass out of the gray matter into the ventral spinal roots or the fiber tracts of the white matter. The axons and dendrites of the Golgi type II cells are largely confined to the neighboring neurons in the gray matter.

A more recent classification of neurons within the gray matter is based on function. These cells are located at all levels of the spinal cord and are grouped into three main categories: root cells, column or tract cells and propriospinal cells.

The root cells are situated in the ventral and lateral gray horns and vary greatly in size. The most prominent features of the root cells are large multipolar elements exceeding 25 m of their somata. The root cells contribute their axons to the ventral roots of the spinal nerves and are grouped into two major divisions: 1) somatic efferent root neurons, which innervate the skeletal musculature; and 2) the visceral efferent root neurons, also called preganglionic autonomic axons, which send their axons to various autonomic ganglia.

The column or tract cells and their processes are located mainly in the dorsal gray horn and are confined entirely within the CNS. The axons of the column cells form longitudinal ascending tracts that ascend in the white columns and terminate upon neurons located rostrally in the brain stem, cerebellum or diencephalon. Some column cells send their axons up and down the cord to terminate in gray matter close to their origin and are known as intersegmental association column cells. Other column cell axons terminate within the segment in which they originate and are called intrasegmental association column cells. Still other column cells send their axons across the midline to terminate in gray matter close to their origin and are called commissure association column cells.

The propriospinal cells are spinal interneurons whose axons do not leave the spinal cord proper. Propriospinal cells account for about 90% of spinal neurons. Some of these fibers also are found around the margin of the gray matter of the cord and are collectively called the fasciculus proprius or the propriospinal or the archispinothalamic tract.

3.5 Spinal Cord Nuclei and Laminae

Spinal neurons are organized into nuclei and laminae.

3.6 Nuclei

The prominent nuclear groups of cell columns within the spinal cord from dorsal to ventral are the marginal zone, substantia gelatinosa, nucleus proprius, dorsal nucleus of Clarke, intermediolateral nucleus and the lower motor neuron nuclei.

Figure 3.7 Spinal cord nuclei and laminae.

Marginal zone nucleus or posterior marginalis, is found at all spinal cord levels as a thin layer of column/tract cells (column cells) that caps the tip of the dorsal horn. The axons of its neurons contribute to the lateral spinothalamic tract which relays pain and temperature information to the diencephalon (Figure 3.7).

Substantia gelatinosa is found at all levels of the spinal cord. Located in the dorsal cap-like portion of the head of the dorsal horn, it relays pain, temperature and mechanical (light touch) information and consists mainly of column cells (intersegmental column cells). These column cells synapse in cell at Rexed layers IV to VII, whose axons contribute to the ventral (anterior) and lateral spinal thalamic tracts. The homologous substantia gelatinosa in the medulla is the spinal trigeminal nucleus.

Nucleus proprius is located below the substantia gelatinosa in the head and neck of the dorsal horn. This cell group, sometimes called the chief sensory nucleus, is associated with mechanical and temperature sensations. It is a poorly defined cell column which extends through all segments of the spinal cord and its neurons contribute to ventral and lateral spinal thalamic tracts, as well as to spinal cerebellar tracts. The axons originating in nucleus proprius project to the thalamus via the spinothalamic tract and to the cerebellum via the ventral spinocerebellar tract (VSCT).

Dorsal nucleus of Clarke is a cell column located in the mid-portion of the base form of the dorsal horn. The axons from these cells pass uncrossed to the lateral funiculus and form the dorsal (posterior) spinocerebellar tract (DSCT), which subserve unconscious proprioception from muscle spindles and Golgi tendon organs to the cerebellum, and some of them innervate spinal interneurons. The dorsal nucleus of Clarke is found only in segments C8 to L3 of the spinal cord and is most prominent in lower thoracic and upper lumbar segments. The homologous dorsal nucleus of Clarke in the medulla is the accessory cuneate nucleus, which is the origin of the cuneocerebellar tract (CCT).

Intermediolateral nucleus is located in the intermediate zone between the dorsal and the ventral horns in the spinal cord levels. Extending from C8 to L3, it receives viscerosensory information and contains preganglionic sympathetic neurons, which form the lateral horn. A large proportion of its cells are root cells which send axons into the ventral spinal roots via the white rami to reach the sympathetic tract as preganglionic fibers. Similarly, cell columns in the intermediolateral nucleus located at the S2 to S4 levels contains preganglionic parasympathetic neurons (Figure 3.7).

Lower motor neuron nuclei are located in the ventral horn of the spinal cord. They contain predominantly motor nuclei consisting of , and motor neurons and are found at all levels of the spinal cord--they are root cells. The a motor neurons are the final common pathway of the motor system, and they innervate the visceral and skeletal muscles.

3.7 Rexed Laminae

The distribution of cells and fibers within the gray matter of the spinal cord exhibits a pattern of lamination. The cellular pattern of each lamina is composed of various sizes or shapes of neurons (cytoarchitecture) which led Rexed to propose a new classification based on 10 layers (laminae). This classification is useful since it is related more accurately to function than the previous classification scheme which was based on major nuclear groups (Figure 3.7).

Laminae I to IV, in general, are concerned with exteroceptive sensation and comprise the dorsal horn, whereas laminae V and VI are concerned primarily with proprioceptive sensations. Lamina VII is equivalent to the intermediate zone and acts as a relay between muscle spindle to midbrain and cerebellum, and laminae VIII-IX comprise the ventral horn and contain mainly motor neurons. The axons of these neurons innervate mainly skeletal muscle. Lamina X surrounds the central canal and contains neuroglia.

Rexed lamina I Consists of a thin layer of cells that cap the tip of the dorsal horn with small dendrites and a complex array of nonmyelinated axons. Cells in lamina I respond mainly to noxious and thermal stimuli. Lamina I cell axons join the contralateral spinothalamic tract; this layer corresponds to nucleus posteromarginalis.

Rexed lamina II Composed of tightly packed interneurons. This layer corresponds to the substantia gelatinosa and responds to noxious stimuli while others respond to non-noxious stimuli. The majority of neurons in Rexed lamina II axons receive information from sensory dorsal root ganglion cells as well as descending dorsolateral fasciculus (DLF) fibers. They send axons to Rexed laminae III and IV (fasciculus proprius). High concentrations of substance P and opiate receptors have been identified in Rexed lamina II. The lamina is believed to be important for the modulation of sensory input, with the effect of determining which pattern of incoming information will produce sensations that will be interpreted by the brain as being painful.

Rexed lamina III Composed of variable cell size, axons of these neurons bifurcate several times and form a dense plexus. Cells in this layer receive axodendritic synapses from A fibers entering dorsal root fibers. It contains dendrites of cells from laminae IV, V and VI. Most of the neurons in lamina III function as propriospinal/interneuron cells.

Rexed lamina IV The thickest of the first four laminae. Cells in this layer receive A axons which carry predominantly non-noxious information. In addition, dendrites of neurons in lamina IV radiate to lamina II, and respond to stimuli such as light touch. The ill-defined nucleus proprius is located in the head of this layer. Some of the cells project to the thalamus via the contralateral and ipsilateral spinothalamic tract.

Rexed lamina V Composed neurons with their dendrites in lamina II. The neurons in this lamina receive monosynaptic information from A, Ad and C axons which also carry nociceptive information from visceral organs. This lamina covers a broad zone extending across the neck of the dorsal horn and is divided into medial and lateral parts. Many of the Rexed lamina V cells project to the brain stem and the thalamus via the contralateral and ipsilateral spinothalamic tract. Moreover, descending corticospinal and rubrospinal fibers synapse upon its cells.

Rexed lamina VI Is a broad layer which is best developed in the cervical and lumbar enlargements. Lamina VI divides also into medial and lateral parts. Group Ia afferent axons from muscle spindles terminate in the medial part at the C8 to L3 segmental levels and are the source of the ipsilateral spinocerebellar pathways. Many of the small neurons are interneurons participating in spinal reflexes, while descending brainstem pathways project to the lateral zone of Rexed layer VI.

Rexed lamina VII This lamina occupies a large heterogeneous region. This region is also known as the zona intermedia (or intermediolateral nucleus). Its shape and boundaries vary along the length of the cord. Lamina VII neurons receive information from Rexed lamina II to VI as well as visceral afferent fibers, and they serve as an intermediary relay in transmission of visceral motor neurons impulses. The dorsal nucleus of Clarke forms a prominent round oval cell column from C8 to L3. The large cells give rise to uncrossed nerve fibers of the dorsal spinocerebellar tract (DSCT). Cells in laminae V to VII, which do not form a discrete nucleus, give rise to uncrossed fibers that form the ventral spinocerebellar tract (VSCT). Cells in the lateral horn of the cord in segments T1 and L3 give rise to preganglionic sympathetic fibers to innervate postganglionic cells located in the sympathetic ganglia outside the cord. Lateral horn neurons at segments S2 to S4 give rise to preganglionic neurons of the sacral parasympathetic fibers to innervate postganglionic cells located in peripheral ganglia.

Rexed lamina VIII Includes an area at the base of the ventral horn, but its shape differs at various cord levels. In the cord enlargements, the lamina occupies only the medial part of the ventral horn, where descending vestibulospinal and reticulospinal fibers terminate. The neurons of lamina VIII modulate motor activity, most probably via g motor neurons which innervate the intrafusal muscle fibers.

Rexed lamina IX Composed of several distinct groups of large a motor neurons and small and motor neurons embedded within this layer. Its size and shape differ at various cord levels. In the cord enlargements the number of motor neurons increase and they form numerous groups. The motor neurons are large and multipolar cells and give rise to ventral root fibers to supply extrafusal skeletal muscle fibers, while the small motor neurons give rise to the intrafusal muscle fibers. The motor neurons are somatotopically organized.

Rexed lamina X Neurons in Rexed lamina X surround the central canal and occupy the commissural lateral area of the gray commissure, which also contains decussating axons.

In summary, laminae I-IV are concerned with exteroceptive sensations, whereas laminae V and VI are concerned primarily with proprioceptive sensation and act as a relay between the periphery to the midbrain and the cerebellum. Laminae VIII and IX form the final motor pathway to initiate and modulate motor activity via , and motor neurons, which innervate striated muscle. All visceral motor neurons are located in lamina VII and innervate neurons in autonomic ganglia.

3.8 White Matter

Surrounding the gray matter is white matter containing myelinated and unmyelinated nerve fibers. These fibers conduct information up (ascending) or down (descending) the cord. The white matter is divided into the dorsal (or posterior) column (or funiculus), lateral column and ventral (or anterior) column (Figure 3.8). The anterior white commissure resides in the center of the spinal cord, and it contains crossing nerve fibers that belong to the spinothalamic tracts, spinocerebellar tracts, and anterior corticospinal tracts. Three general nerve fiber types can be distinguished in the spinal cord white matter: 1) long ascending nerve fibers originally from the column cells, which make synaptic connections to neurons in various brainstem nuclei, cerebellum and dorsal thalamus, 2) long descending nerve fibers originating from the cerebral cortex and various brainstem nuclei to synapse within the different Rexed layers in the spinal cord gray matter, and 3) shorter nerve fibers interconnecting various spinal cord levels such as the fibers responsible for the coordination of flexor reflexes. Ascending tracts are found in all columns whereas descending tracts are found only in the lateral and the anterior columns.

Figure 3.8 The spinal cord white matter and its three columns, and the topographical location of the main ascending spinal cord tracts.

Four different terms are often used to describe bundles of axons such as those found in the white matter: funiculus, fasciculus, tract, and pathway. Funiculus is a morphological term to describe a large group of nerve fibers which are located in a given area (e.g., posterior funiculus). Within a funiculus, groups of fibers from diverse origins, which share common features, are sometimes arranged in smaller bundles of axons called fasciculus, (e.g., fasciculus proprius [Figure 3.8]). Fasciculus is primarily a morphological term whereas tracts and pathways are also terms applied to nerve fiber bundles which have a functional connotation. A tract is a group of nerve fibers which usually has the same origin, destination, and course and also has similar functions. The tract name is derived from their origin and their termination (i.e., corticospinal tract - a tract that originates in the cortex and terminates in the spinal cord; lateral spinothalamic tract - a tract originated in the lateral spinal cord and ends in the thalamus). A pathway usually refers to the entire neuronal circuit responsible for a specific function, and it includes all the nuclei and tracts which are associated with that function. For example, the spinothalamic pathway includes the cell bodies of origin (in the dorsal root ganglia), their axons as they project through the dorsal roots, synapses in the spinal cord, and projections of second and third order neurons across the white commissure, which ascend to the thalamus in the spinothalamic tracts.

3.9 Spinal Cord Tracts

The spinal cord white matter contains ascending and descending tracts.

Ascending tracts (Figure 3.8). The nerve fibers comprise the ascending tract emerge from the first order (1) neuron located in the dorsal root ganglion (DRG). The ascending tracts transmit sensory information from the sensory receptors to higher levels of the CNS. The ascending gracile and cuneate fasciculi occupying the dorsal column, and sometimes are named the dorsal funiculus. These fibers carry information related to tactile, two point discrimination of simultaneously applied pressure, vibration, position, and movement sense and conscious proprioception. In the lateral column (funiculus), the neospinothalamic tract (or lateral spinothalamic tract) is located more anteriorly and laterally, and carries pain, temperature and crude touch information from somatic and visceral structures. Nearby laterally, the dorsal and ventral spinocerebellar tracts carry unconscious proprioception information from muscles and joints of the lower extremity to the cerebellum. In the ventral column (funiculus) there are four prominent tracts: 1) the paleospinothalamic tract (or anterior spinothalamic tract) is located which carry pain, temperature, and information associated with touch to the brain stem nuclei and to the diencephalon, 2) the spinoolivary tract carries information from Golgi tendon organs to the cerebellum, 3) the spinoreticular tract, and 4) the spino-tectal tract. Intersegmental nerve fibers traveling for several segments (2 to 4) and are located as a thin layer around the gray matter is known as fasciculus proprius, spinospinal or archispinothalamic tract. It carries pain information to the brain stem and diencephalon.

Descending tracts (Figure 3.9). The descending tracts originate from different cortical areas and from brain stem nuclei. The descending pathway carry information associated with maintenance of motor activities such as posture, balance, muscle tone, and visceral and somatic reflex activity. These include the lateral corticospinal tract and the rubrospinal tracts located in the lateral column (funiculus). These tracts carry information associated with voluntary movement. Other tracts such as the reticulospinal vestibulospinal and the anterior corticospinal tract mediate balance and postural movements (Figure 3.9). Lissauer's tract, which is wedged between the dorsal horn and the surface of the spinal cord carry the descending fibers of the dorsolateral funiculus (DFL), which regulate incoming pain sensation at the spinal level, and intersegmental fibers. Additional details about ascending and descending tracts are described in the next few chapters.

Figure 3.9 The main descending spinal cord tracts.

3.10 Dorsal Root

Figure 3.10 Spinal cord section with its ventral and dorsal root fibers and ganglion.

Information from the skin, skeletal muscle and joints is relayed to the spinal cord by sensory cells located in the dorsal root ganglia. The dorsal root fibers are the axons originated from the primary sensory dorsal root ganglion cells. Each ascending dorsal root axon, before reaching the spinal cord, bifurcates into ascending and descending branches entering several segments below and above their own segment. The ascending dorsal root fibers and the descending ventral root fibers from and to discrete body areas form a spinal nerve (Figure 3.10). There are 31 paired spinal nerves. The dorsal root fibers segregate into lateral and medial divisions. The lateral division contains most of the unmyelinated and small myelinated axons carrying pain and temperature information to be terminated in the Rexed laminae I, II, and IV of the gray matter. The medial division of dorsal root fibers consists mainly of myelinated axons conducting sensory fibers from skin, muscles and joints; it enters the dorsal/posterior column/funiculus and ascend in the dorsal column to be terminated in the ipsilateral nucleus gracilis or nucleus cuneatus at the medulla oblongata region, i.e., the axons of the first-order (1) sensory neurons synapse in the medulla oblongata on the second order (2) neurons (in nucleus gracilis or nucleus cuneatus). In entering the spinal cord, all fibers send collaterals to different Rexed lamina.

Axons entering the cord in the sacral region are found in the dorsal column near the midline and comprise the fasciculus gracilis, whereas axons that enter at higher levels are added in lateral positions and comprise the fasciculus cuneatus (Figure 3.11). This orderly representation is termed somatotopic representation.

Figure 3.11 Somatotopical representation of the spinal thalamic tract and the dorsal column.

3.11 Ventral Root

Ventral root fibers are the axons of motor and visceral efferent fibers and emerge from poorly defined ventral lateral sulcus as ventral rootlets. The ventral rootlets from discrete spinal cord section unite and form the ventral root, which contain motor nerve axons from motor and visceral motor neurons. The motor nerve axons innervate the extrafusal muscle fibers while the small motor neuron axons innervate the intrafusal muscle fibers located within the muscle spindles. The visceral neurons send preganglionic fibers to innervate the visceral organs. All these fibers join the dorsal root fibers distal to the dorsal root ganglion to form the spinal nerve (Figure 3.10).

3.12 Spinal Nerve Roots

The spinal nerve roots are formed by the union of dorsal and ventral roots within the intervertebral foramen, resulting in a mixed nerve joined together and forming the spinal nerve (Figure 3.10). Spinal nerve rami include the dorsal primary nerves (ramus), which innervates the skin and muscles of the back, and the ventral primary nerves (ramus), which innervates the ventral lateral muscles and skin of the trunk, extremities and visceral organs. The ventral and dorsal roots also provide the anchorage and fixation of the spinal cord to the vertebral cauda.

3.13 Blood Supply of the Spinal Cord

The arterial blood supply to the spinal cord in the upper cervical regions is derived from two branches of the vertebral arteries, the anterior spinal artery and the posterior spinal arteries (Figure 3.12). At the level of medulla, the paired anterior spinal arteries join to form a single artery that lies in the anterior median fissure of the spinal cord. The posterior spinal arteries are paired and form an anastomotic chain over the posterior aspect of the spinal cord. A plexus of small arteries, the arterial vasocorona, on the surface of the cord constitutes an anastomotic connection between the anterior and posterior spinal arteries. This arrangement provides uninterrupted blood supplies along the entire length of the spinal cord.

Figure 3.12 The spinal cord arterial circulation.

At spinal cord regions below upper cervical levels, the anterior and posterior spinal arteries narrow and form an anastomotic network with radicular arteries. The radicular arteries are branches of the cervical, trunk, intercostal & iliac arteries. The radicular arteries supply most of the lower levels of the spinal cord. There are approximately 6 to 8 pairs of radicular arteries supplying the anterior and posterior spinal cord (Figure 3.12).

Test Your Knowledge

The spinal cord...

A. Occupies the lumbar cistern

B. Has twelve (12) cervical segments

C. Contains the cell bodies of postganglionic sympathetic efferent neurons

D. Ends at the conus medullaris

E. Has no arachnoid membrane

The spinal cord...

A. Occupies the lumbar cistern This answer is INCORRECT.

The spinal cord does not occupy the lumbar cistern.

B. Has twelve (12) cervical segments

C. Contains the cell bodies of postganglionic sympathetic efferent neurons

D. Ends at the conus medullaris

E. Has no arachnoid membrane

The spinal cord...

A. Occupies the lumbar cistern

B. Has twelve (12) cervical segments This answer is INCORRECT.

The spinal cord has seven (7) cervical segments.

C. Contains the cell bodies of postganglionic sympathetic efferent neurons

D. Ends at the conus medullaris

E. Has no arachnoid membrane

The spinal cord...

A. Occupies the lumbar cistern

B. Has twelve (12) cervical segments

C. Contains the cell bodies of postganglionic sympathetic efferent neurons This answer is INCORRECT.

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Anatomy of the Spinal Cord (Section 2, Chapter 3 ...

Spinal Cord Stem Cells Comments Off on Anatomy of the Spinal Cord (Section 2, Chapter 3 … | November 2nd, 2015

Presented at the 8th World Congress for Hair Research (2014) Jeju Island, South Korea.

Understanding molecular mechanisms for regeneration of hair follicles during wound healing provides new opportunities for developing treatments for hair loss and other skin disorders. We show that fibroblast growth factor 9 (fgf9) modulates hair follicle regeneration following wounding of adult mice. Inhibition of fgf9 during wound healing severely impedes this wound-induced hair follicle neogenesis (WIHN). Conversely, overexpression of fgf9 results in a 2-3 fold increase in the number of neogenic hair follicles. Remarkably, gamma-delta T cells in the wound dermis are the initial source of fgf9. Deletion of fgf9 gene in T cells in Lck-Cre;floxed fgf9 results in a marked reduction in WIHN. Similarly, mice lacking gamma-delta T cells demonstrate impaired follicular neogenesis.

We found that fgf9, secreted by gamma-delta T cells, initiates a regenerative response by triggering Wnt expression and subsequent Wnt activation in wound fibroblasts. Employing a unique feedback mechanism, activated fibroblasts then express fgf9, thus amplifying Wnt activity throughout the wound dermis during a critical phase of skin regeneration. Strikingly, humans lack a robust population of resident dermal gamma-delta T cells, potentially explaining their inability to regenerate hair.

These findings which highlight the essential relationship between the immune system and tissue regeneration, establish the importance of fgf9 in hair follicle regeneration and suggests its applicability for therapeutic use in humans.

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Dr George Cotsarelis: Hair Follicle Stem Cells & Skin ...

Skin Stem Cells Comments Off on Dr George Cotsarelis: Hair Follicle Stem Cells & Skin … | November 2nd, 2015

Welcome to the Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research at UCSF, one of the largest and most comprehensive programs of its kind in the United States.

In some 125 labs, scientists are carrying out studies, in cell culture and animals, aimed at understanding and developing treatment strategies for such conditions as heart disease, diabetes, epilepsy, multiple sclerosis, Parkinsons disease, Lou Gehrigs disease, spinal cord injury and cancer.

While the scientific foundation for the field is still being laid, UCSF scientists are beginning to move their work toward human clinical trials. A team of pediatric specialists and neurosurgeons is carrying out the second brain stem cell clinical trial ever conducted in the United States, focusing on a rare disease, inherited in boys, known as Pelizaeus-Merzbacher disease.

Others are working to develop strategies for treating diabetes, brain tumors, liver disease and epilepsy. The approach for treating epilepsy potentially also could be used to treat Parkinsons disease, as well as the pain and spasticity that follow brain and spinal cord injury.

The center is structured along seven research pipelines aimed at driving discoveries from the lab bench to the patient. Each pipeline focuses on a different organ system, including the blood, pancreas, liver, heart, reproductive organs, nervous system, musculoskeletal tissues and skin. And each of these pipelines is overseen by two leaders of international standing one representing the basic sciences and one representing clinical research. This approach has proven successful in the private sector for driving the development of new therapies.

The center, like all of UCSF, fosters a highly collaborative culture, encouraging a cross-pollination of ideas among scientists of different disciplines and years of experience. Researchers studying pancreatic beta cells damaged in diabetes collaborate with those who study nervous system diseases because stem cells undergo similar molecular signaling on the way to becoming both cell types. The opportunity to work in this culture has drawn some of the countrys premier young scientists to the center.

While the focus of the science is the future, UCSFs history in the field dates back to 1981, when Gail Martin, PhD, co-discovered embryonic stem cells in mice and coined the term embryonic stem cell. Two decades later, UCSFs Roger Pedersen, PhD, developed two of the first human embryonic stem cell lines, following the groundbreaking discovery by University of Wisconsins James Thomson, PhD, of a way to derive the cells.

Today, the Universitys faculty includes Shinya Yamanaka, MD, PhD, of the UCSF-affiliated J. David Gladstone Institutes and Kyoto University. His discovery in 2006 of a way to reprogram ordinary skin cells back to an embryonic-like state has given hope that someday these cells might be used in regenerative medicine.

Yamanakas seminal finding highlights the unexpected and dramatic discoveries that can characterize scientific research. In labs throughout UCSF and beyond, the goal is to move such findings into patients.

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Introduction

A bone marrow transplant, alsoknown as a haemopoietic stem cell transplant, replaces damaged bone marrow with healthy bone marrow stem cells.

Bone marrow is aspongytissue found in the hollow centres of some bones. It contains specialist stem cells, which produce the body's blood cells.

Stem cells in bone marrow produce three important types of blood cells:

Bone marrow transplants are often needed to treat conditions thatdamage bone marrow. If bone marrow is damaged, it is no longer able to produce normal blood cells. The new stem cells take over blood cellproduction.

Conditions that bone marrow transplants are used to treat include:

Read more about why a bone marrow transplantis needed.

A bone marrow transplant involves taking healthy stem cells from the bone marrow of one person and transferring them to the bone marrow of another person.

In some cases, it may be possible to take the bone marrow from your own body. This is known as an autologous transplantation. Before it is returned, the bone marrow is cleared of any damaged or diseased cells.

A bone marrowtransplant has five stages. These are:

Having a bone marrow transplant can be an intensive and challenging experience. Many people take up to a year to fully recover from the procedure.

Read more about what happens during a bone marrow transplant.

Bone marrow transplants are usually only recommended if:

Read more about who can have a bone marrow transplant.

Bone marrow transplants arecomplicated procedures with significant risks.

In some cases, the transplanted cells (graft cells) recognise the recipient's cells as "foreign"and try to attack them. This is known as graft versus host disease (GvHD).

The risk of infectionis alsoincreased because your immune system is weakened when you're conditioned (prepared) for the transplant.

Read more about the risks of having a bone marrow transplant.

It's nowpossible to harvest stem cells from sources other than bone marrow.

Peripheral blood stem cell donation involves injectinga medicine into the donor's blood thatcauses the stem cells to moveout of the bone marrow and into the bloodstream where theycan be harvested (collected).

The advantage of this type of stem cell donation is that the donor doesn't needa general anaesthetic.

Stem cells can also be collectedfrom the placenta and umbilical cord of a newborn baby and stored in a laboratory until they're needed.

Cord blood stem cells are very usefulbecause they don't need to be as closely matched as bone marrow or peripheral blood stem cells for a successful outcome.

Find out more about theNHS Cord Blood Bank(external link).

Page last reviewed: 18/02/2014

Next review due: 18/02/2016

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Bone marrow transplant - NHS Choices

Bone Marrow Stem Cells Comments Off on Bone marrow transplant – NHS Choices | October 28th, 2015

In the past year, Japan has accelerated its position as a hub for regenerative medicine research, largely driven by support from Prime Minister Shinzo Abe who has identified regenerative medicine and cellular therapy as key to the Japans strategy to drive economic growth. The Prime Minister has encouraged a growing range of collaborations between private industry and academic partners through an innovative legal framework approved last fall. He has also initiated campaigns to drive technological advances in drugs and devices by connecting private companies with public funding sources. The result has been to drive progress in both basic and applied research involving induced pluripotent stem cells (iPS cells) and related stem cell technologies.

Indeed, 2013 represented a landmark year in Japan, as it saw the first cellular therapy involving transplant of iPS cells into humans initiated at the RIKEN Center in Kobe, Japan.[1] The RIKEN Center is Japans largest, most comprehensive research institution, backed by both Japans Health Ministry and government. To speed things along, RIKEN did not seek permission for a clinical trial involving iPS cells, but instead applied for a type of pretrial clinical research allowed under Japanese regulations.

As such, this pretrial clinical research allowed the RIKEN research team to test the use of iPS cells for the treatment of wet-type age-related macular degeneration (AMD) on a very small scale, in only a handful of patients. Unfortunately, this trial was paused in 2015 due to safety concerns and is currently on hold pending further investigation. Regardless, the trial has set a new international standard for considering iPS cells as a viable cell type to investigate for clinical purposes.

If this iPS cell trial is ultimately reinstated, it will help to accelerate the acceptance of cellular therapies within other countries. Currently, the main concern surrounding iPS cell-based cellular therapy isthe fear of creating multiplying cell populations within patients. Even treatments using embryonic stem cells, which have been cultured and studied for decades, are still in very early clinical trials, so it is not surprising that clinical trials using iPS cells are being conducted on a small-scale, experimental level.[2]

Japan has a unique affection for iPS cells, as the cells were originally discovered by the Japanese scientist, Shinya Yamanaka of Kyoto University. Mr. Yamanaka was awarded the Nobel Prize in Physiology or Medicine for 2012, an honor shared jointly with John Gurdon, for the discovery that mature cells can be reprogrammed to become pluripotent. In addition, Japans Education Ministry said its planning to spend 110 billion yen ($1.13 billion) on induced pluripotent stem cell research during the next 10 years, and the Japanese parliament has been discussing bills that would speed the approval process and ensure the safety of such treatments.[3] In April, Japanese parliament even passed a law calling for Japan to make regenerative medical treatments like iPSC technology available for its citizens ahead of the rest of the world.[4] If those forces were not enough, Masayo Takahashi of the RIKEN Center for Developmental Biology in Kobe, Japan, who is heading the worlds first clinical research using iPSCs in humans, was also chosen by the journal Natureas one of five scientists to watch in 2014.[5]

In summary, Japan is the clear global leader with regard to investment in iPS cell technologies and therapies. While progress with stem cells has not been without setbacks within Japan, including a recent scandal at the RIKEN Institute that involved falsely manipulated research findings and the aforementioned hold on the first clinical trial involving transplant of an iPS cell product into humans, Japan has emerged from these troubles to become the most liberalized and progressive nation pursuing the development of iPS cell products and services.

To learn more about induced pluripotent stem cell (iPSC)industry trends and events, view the Compete 2015-16 Induced Pluripotent Stem Cell (iPSC) Industry Report.

To receive future posts about the stem cell industry, sign-up here. We will never share your information with anyone, and you can opt-out at any time. No spam ever, just great stuff.

BioInformant is the only research firm that has served the stem cell sector since it emerged. Our management team comes from a BioInformatics background the science of collecting and analyzing complex genetic codes and applies these techniques to the field of market research. BioInformant has been featured on news outlets including the Wall Street Journal, Nature Biotechnology, CBS News, Medical Ethics, and the Center for BioNetworking.

Serving Fortune 500 leaders that include GE Healthcare, Pfizer, Goldman Sachs, Beckton Dickinson, and Thermo Fisher Scientific, BioInformant is your global leader in stem cell industry data.

Footnotes [1] Dvorak, K. (2014).Japan Makes Advance on Stem-Cell Therapy [Online]. Available at: http://online.wsj.com/news/articles/SB10001424127887323689204578571363010820642. Web. 14 Apr. 2015. [2] Note: In the United States, some patients have been treated with retina cells derived from embryonic stem cells (ESCs) to treat macular degeneration. There was a successful patient safety test for this stem cell treatment last year that was conducted at the Jules Stein Eye Institute in Los Angeles. The ESC-derived cells used for this study were developed by Advanced Cell Technology, Inc, a company located in Marlborough, Massachusetts. [3] Dvorak, K. (2014).Japan Makes Advance on Stem-Cell Therapy [Online]. Available at: http://online.wsj.com/news/articles/SB10001424127887323689204578571363010820642. Web. 8 Apr. 2015. [4] Ibid. [5] Riken.jp. (2014).RIKEN researcher chosen as one of five scientists to watch in 2014 | RIKEN [Online]. Available at: http://www.riken.jp/en/pr/topics/2014/20140107_1/. Web. 14 Apr. 2015.

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For years, the cornerstones of cancer treatment have been surgery, chemotherapy, and radiation therapy. Over the last decade, targeted therapies like imatinib (Gleevec) and trastuzumab (Herceptin)drugs that target cancer cells by homing in on specific molecular changes seen primarily in those cellshave also emerged as standard treatments for a number of cancers.

Illustration of the components of second- and third-generation chimeric antigen receptor T cells. (Adapted by permission from the American Association for Cancer Research: Lee, DW et al. The Future Is Now: Chimeric Antigen Receptors as New Targeted Therapies for Childhood Cancer. Clin Cancer Res; 2012;18(10); 278090. doi:10.1158/1078-0432.CCR-11-1920)

And now, despite years of starts and stutter steps, excitement is growing for immunotherapytherapies that harness the power of a patients immune system to combat their disease, or what some in the research community are calling the fifth pillar of cancer treatment.

One approach to immunotherapy involves engineering patients own immune cells to recognize and attack their tumors. And although this approach, called adoptive cell transfer (ACT), has been restricted to small clinical trials so far, treatments using these engineered immune cells have generated some remarkable responses in patients with advanced cancer.

For example, in several early-stage trials testing ACT in patients with advanced acute lymphoblastic leukemia (ALL) who had few if any remaining treatment options, many patients cancers have disappeared entirely. Several of these patients have remained cancer free for extended periods.

Equally promising results have been reported in several small trials involving patients with lymphoma.

These are small clinical trials, their lead investigators cautioned, and much more research is needed.

But the results from the trials performed thus far are proof of principle that we can successfully alter patients T cells so that they attack their cancer cells, said one of the trial's leaders, Renier J. Brentjens, M.D., Ph.D., of Memorial Sloan Kettering Cancer Center (MSKCC) in New York.

Adoptive cell transfer is like giving patients a living drug, continued Dr. Brentjens.

Thats because ACTs building blocks are T cells, a type of immune cell collected from the patients own blood. After collection, the T cells are genetically engineered to produce special receptors on their surface called chimeric antigen receptors (CARs). CARs are proteins that allow the T cells to recognize a specific protein (antigen) on tumor cells. These engineered CAR T cells are then grown in the laboratory until they number in the billions.

The expanded population of CAR T cells is then infused into the patient. After the infusion, if all goes as planned, the T cells multiply in the patients body and, with guidance from their engineered receptor, recognize and kill cancer cells that harbor the antigen on their surfaces.

Although adoptive cell transfer has been restricted to small clinical trials so far, treatments using these engineered immune cells have generated some remarkable responses in patients with advanced cancer.

This process builds on a similar form of ACT pioneered by Steven Rosenberg, M.D., Ph.D., and his colleagues from NCIs Surgery Branch for patients with advanced melanoma.

The CAR T cells are much more potent than anything we can achieve with other immune-based treatments being studied, said Crystal Mackall, M.D., of NCIs Pediatric Oncology Branch (POB).

Even so, investigators working in this field caution that there is still much to learn about CAR T-cell therapy. But the early results from trials like these have generated considerable optimism.

CAR T-cell therapy eventually may become a standard therapy for some B-cell malignancies like ALL and chronic lymphocytic leukemia, Dr. Rosenberg wrote in a Nature Reviews Clinical Oncology article.

More than 80 percent of children who are diagnosed with ALL that arises in B cellsthe predominant type of pediatric ALLwill be cured by intensive chemotherapy.

For patients whose cancers return after intensive chemotherapy or a stem cell transplant, the remaining treatment options are close to none, said Stephan Grupp, M.D., Ph.D., of the Childrens Hospital of Philadelphia (CHOP) and the lead investigator of a trial testing CAR T cells primarily in children with ALL. This treatment may represent a much-needed new option for such patients, he said.

Trials of CAR T cells in adults and children with leukemia and lymphoma have used T cells engineered to target the CD19 antigen, which is present on the surface of nearly all B cells, both normal and cancerous.

In the CHOP trial, which is being conducted in collaboration with researchers from the University of Pennsylvania, all signs of cancer disappeared (a complete response) in 27 of the 30 patients treated in the study, according to findings published October 16 in the New England Journal of Medicine.

Nineteen of the 27 patients with complete responses have remained in remission, the study authors reported, with 15 of these patients receiving no further therapy and 4 patients withdrawing from the trial to receive other therapy.

According to the most recent data from a POB trial that included children with ALL, 14 of 20 patients had a complete response. And of the 12 patients who had no evidence of leukemic cells, called blasts, in their bone marrow after CAR T-cell treatment, 10 have gone on to receive a stem cell transplant and remain cancer free, reported the studys lead investigator, Daniel W. Lee, M.D., also of the POB.

Dr. Crystal Mackall

Our findings strongly suggest that CAR T-cell therapy is a useful bridge to bone marrow transplant for patients who are no longer responding to chemotherapy, Dr. Lee said.

Similar results have been seen in phase I trials of adult patients conducted at MSKCC and NCI.

In findings published in February 2014, 14 of the 16 participants in the MSKCC trial treated to that point had experienced complete responses, which in some cases occurred 2 weeks or sooner after treatment began. Of those patients who were eligible, 7 underwent a stem cell transplant and are still cancer free.

The NCI-led trial of CAR T cells included 15 adult patients, the majority of whom had advanced diffuse large B-cell lymphoma. Most patients in the trial had either complete or partial responses, reported James Kochenderfer, M.D., and his NCI colleagues.

Our data provide the first true glimpse of the potential of this approach in patients with aggressive lymphomas that, until this point, were virtually untreatable, Dr. Kochenderfer said. [NCI Surgery Branch researchers have also reported promising results from one of the first trials testing CAR T cells derived from donors, rather than the patients themselves, to treat leukemia and lymphoma.]

Other findings from the trials have been encouraging, as well. For example, the number of CAR T cells increased dramatically after infusion into patients, as much as 1,000-fold in some individuals. In addition, after infusion, CAR T cells were detected in the central nervous system, a so-called sanctuary site where solitary cancer cells that have evaded chemotherapy or radiation may hide. In two patients in the NCI pediatric trial, the CAR T-cell treatment eradicated cancer that had spread to the central nervous system.

If CAR T cells can persist at these sites, it could help fend off relapses, Dr. Mackall noted.

CAR T-cell therapy can cause several worrisome side effects, perhaps the most troublesome being cytokine-release syndrome.

The infused T cells release cytokines, which are chemical messengers that help the T cells carry out their duties. With cytokine-release syndrome, there is a rapid and massive release of cytokines into the bloodstream, which can lead to dangerously high fevers and precipitous drops in blood pressure.

Cytokine-release syndrome is a common problem in patients treated with CAR T cells. In the POB and CHOP trials, patients with the most extensive disease prior to receiving the CAR T cells were more likely to experience severe cases of cytokine-release syndrome.

For most patients, trial investigators have reported, the side effects are mild enough that they can be managed with standard supportive therapies, including steroids.

The research team at CHOP noticed that patients experiencing severe reactions all had particularly high levels of IL-6, a cytokine that is secreted by T cells and macrophages in response to inflammation. So they turned to two drugs that are approved to treat inflammatory conditions like juvenile arthritis: etanercept (Enbrel) and tocilizumab (Actemra), the latter of which blocks IL-6 activity.

The patients had excellent responses to the treatment, Dr. Grupp said. We believe that [these drugs] will be a major part of toxicity management for these patients.

The other two teams subsequently used tocilizumab in several patients. Dr. Brentjens agreed that both drugs could become a useful way to help manage cytokine-release syndrome because, unlike steroids, they dont appear to affect the infused CAR T cells activity or proliferation.

Even with these encouraging preliminary findings, more research is needed before CAR T-cell therapy becomes a routine option for patients with ALL.

We need to treat more patients and have longer follow-up to really say what the impact of this therapy is [and] to understand its true performance characteristics, Dr. Grupp said.

We need to treat more patients and have longer follow-up to really say what the impact of this therapy is [and] to understand its true performance characteristics.

Dr. Stephan Grupp

Several other trials testing CAR T cells in children and adults are ongoing and, with greater interest and involvement from the pharmaceutical and biotechnology sector, more trials testing CAR T cells are being planned.

Researchers are also studying ways to improve on the positive results obtained to date, including refining the process by which the CAR T cells are produced.

Research groups like Dr. Brentjens are also working to make a superior CAR T cell, including developing a better receptor and identifying better targets.

For example, Dr. Lee and his colleagues at NCI have developed CAR T cells that target the CD22 antigen, which is also present on most B cells, although in smaller quantities than CD19. The CD22-targeted T cells, he believes, could be used in concert with CD19-targeted T cells as a one-two punch in ALL and other B-cell cancers. NCI researchers hope to begin the first clinical trial testing the CD22-targeted CAR T cells in November 2014.

Based on the success thus far, several research groups across the country are turning their attention to developing engineered T cells for other cancers, including solid tumorslike pancreatic and brain cancers.

The stage has now been set for greater progress, Dr. Lee believes.

NCI investigators, for example, now have a platform to plug and play better CARs into that system, without a lot of additional R&D time, he continued. Everything else should now come more rapidly.

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We observed similar stem cell plasticity when we purified and tested the myoepithelial stem cells from sweat glands (Lu et al., 2012; Blanpain and Fuchs, 2014). Similar to myoepithelial stem cells of mammary glands, these stem cells normally act unipotently and only replenish dying myoepithelial cells of the gland. However, when purified by fluorescence activated cell sorting (FACS) and transplanted directly into a mammary fat pad, the stem cells can regenerate the complete bi-layered gland, and the new luminal cells secrete sweat. Moreover, when engrafted to the skin, these stem cells can make epidermis. An area of interest in my lab is to understand the environmental cues that dictate the fascinating plasticity of epithelial stem cells, and to elucidate the chromatin remodeling that leads to the changes in gene expression necessary to generate different tissues from a common progenitor.

To understand how a stem cell chooses its differentiation pathway, we have taken several approaches. An ongoing approach of the lab is to express different fluorescent proteins under the control of various skin promoters, active at different stages in stem cells and their lineages. Through FACS, we've purified cells at different time points along the lineages and generated a battery of lineage-specific profiles, enabling us to define at an mRNA (RNA-seq) and chromatin (ChIP-seq) level how stem cells change as they transition from quiescence to activation to lineage determination. Our global objective is to exploit this information to understand how stem cells receive signals, change their program of gene expression and select a lineage. We also want to understand the functional significance of these changes. The beauty of the hair follicle as a model is that it is currently the only system where sufficient quantities of stem cells can be isolated directly from their native niche in order to carry out whole-genome wide analyses in vivo. This eliminates the caveats arising from culturing cells, namely induction of a stress response and large-scale epigenetic changes in gene expression.

For the hair follicle, >150 mRNAs are selectively upregulated in the bulge stem cells relative to their short-lived progeny (Tumbar et al., 2004; Blanpain et al., 2004; Keyes et al., 2013). A number of these changes are in transcription factors and epigenetic regulators. Weve conducted in vivo chromatin immunoprecipitation and high throughput sequencing (ChIP-seq) on chromatin from hair follicle stem cells (HFSCs) and their short-lived progeny. Bioinformatics reveals which genes bind these transcription factors, and how this changes as the stem cells progress to form transiently dividing cells that then terminally differentiate along one of the 7 distinct concentric cell layers that constitute the hair and its channel. By conducting high throughput RNA sequencing (RNA-seq) on HFSCs lacking each of these genes, weve learned which target genes depend upon binding these transcription factors. Finally, by engineering inducible-conditional knockouts to selectively remove these transcription factors in the stem cells, weve learned the physiological relevance of these factors.

Based upon these analyses, TCF3/TCF4, LHX2 and SOX9 are all essential for maintaining the hair follicle stem cells in their native niche (Nguyen et al., 2006; 2009; Rhee et al., 2006; Folgueras et al., 2013; Lien et al., 2011; 2014; Nowak et al., 2008; Kadaja et al., 2014). In addition, LHX2 represses sebaceous gland differentiation: following its loss, the stem cell niche soon becomes a sebaceous gland (Folgueras et al., 2013). SOX9 represses epidermal differentiation: following its loss, the niche becomes an epidermal cyst (Kadaja et al., 2014). TCF3 and TCF4 repress HF differentiation: following their loss, quiescent HFSCs precociously activate a new hair cycle (Lien et al., 2014). TCF3 and TCF4 can partner with -catenin, which is stabilized and becomes nuclear upon Wnt signaling: if -catenin is silenced in the quiescent HFSCs, they never reenter a new hair cycle. In their native niche, quiescent HFSCs express a transcriptional repressor TLE4 which binds to TCF3 and TCF4: our findings are consistent with the view that Wnt signaling functions by relieving TCF3/4/TLE4-mediated repression (Lien et al., 2014).

NFATc1 is required for maintaining HFSC quiescence, and in its absence, HFs cycle precociously (Horsley et al., 2008). Additionally, NFATc1 is downstream of BMP signaling, offering a potential explanation as to why BMP signaling must be lowered to activate hair cycling. A major feature of the aging HFSC signature is elevated NFATc1 target genes, and we can stimulate old follicles by inhibiting NFATc1 (Keyes et al., 2013). A major question still to be answered is whether HFSCs have an endless capacity for hair cycling and whether this same phenomenon operates in aging scalp hairs in humans. If so, these findings may open new doors for future therapeutics.

NFiB is a transcription factor which is specific to the HFSCs, but functions by repressing the expression of genes that are essential for the differentiation of the melanocyte stem cells, which reside within the same stem cell niche (Chang et al., 2013). These two stem cell populations must be activated at the same time so that differentiating melanocytes can transfer pigment to the differentiating hair cells to provide the natural coloring to our hair. Loss of NFiB uncouples this crosstalk and leads to the precocious activation of a key NFiB target gene that encodes a secreted melanocyte differentiation factor (Chang et al., 2013).

There are a number of additional transcription factors and epigenetic regulators which are enhanced in the complex milieu of HF stem cell chromatin, and there is still much to be learned. Of the epigenetic regulators, weve thus far examined only the role of polycomb chromatin repressor complexes, which weve shown function critically in controlling the fate switch from a stem cell to a committed, transit-amplifying state (Ezhkova et al., 2009; 2011; Lien et al., 2011). In coming years, we will continue to systematically work our way through the functional significance and mechanism of action of epigenetic and transcriptional controls on stem cells as they transit from a quiescent to activated to committed state. When coupled with our recent ability to efficiently knockdown genes in a few days using lentiviral-mediated shRNA delivery (Beronja et al., 2010), this now becomes a powerful tool for exploiting bioinformatics analyses to gain biological insights.

Our ultimate goal is to understand how external signals from the surrounding niche microenvironment impact chromatin dynamics to achieve tissue production. Equally important will be the expression of specific genes that enables them to remodel their cytoskeleton and adhesive contacts and either form a stratified epidermis or an epithelial bud that can then develop into a hair follicle (Perez-Moreno et al., 2003; Blanpain and Fuchs, 2009; Hsu et al., 2014). While our model is the skin, the problem is a general one of how a single epithelial stem cell gives rise to a spatially organized, functional tissue. It is also integrally linked to understanding the basis of cancer progression.

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The Rockefeller University Stem Cells of the Skin and ...

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Founded in 2009 by Nobel prize winner Professor Sir Martin Evans and Ajan Reginald, former Global Head of Emerging Technologies at Roche, CTL develops life-saving and life altering regenerative medicines. CTLs team of scientists, physicians, and experienced management have discovered and developed a pipeline of world-class regenerative medicines.

Sir Martin Evans' unique expertise in discovering rare stem cells led to CTLs innovative drug discovery engine that can uniquely isolate very rare and potent tissue specific stem cells. This exceptional class of cells is then engineered into unique disease-specific cellular regenerative medicines. Each medicine is disease specific and forms part of CTLs world-class portfolio of four off the shelf blockbuster medicines all scheduled for launch before 2020.

The products in late stage clinical trials include Heartcel which regenerates the damaged heart of adults with coronary artery malformations and children with Kawasaki Disease and Bland White Garland Syndrome. In 2014, Heartcel reported unprecedented heart regeneration clinical trial results and is scheduled to launch in 2018 to treat ~400,000 patients worldwide. Myocardion is in Phase II/III trials and treats mild-moderate heart failure affecting 10 million patients worldwide. Tendoncel is the worlds first topical regenerative medicine, for early intervention of severe tendon injuries, and has completed Phase II trials. It is designed to treat the >1 million severe tendon injuries each year in the US and Europe. Skincel is for skin regeneration, and is due to complete Phase II trials in 2015. It is designed to address ulceration and wrinkles.

CTL combines world-class science and management expertise to bring life-saving regenerative medicines to market.

European Society of Gene and Cell Therapy Congress, 17-20 September 2015, Helsinki,Finland (ESGCT 2015)

4th International Conference and Exhibition on Cell & Gene Therapy, August 10-12, 2015, London (CGT 2015)

The International Society for Stem Cell Research Annual Meeting, 24th-27th June 2015, Stockholm, Sweden (ISSCR 2015)

British Society for Gene and Cell Therapy Annual Conference, 9th-11th June 2015, Strathclyde, Glasgow (BSGCT 2015)

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Induced pluripotent stem cells (also known as iPS cells or iPSCs) are a type of pluripotent stem cell that can be generated directly from adult cells. The iPSC technology was pioneered by Shinya Yamanakas lab in Kyoto, Japan, who showed in 2006 that the introduction of four specific genes encoding transcription factors could convert adult cells into pluripotent stem cells.[1] He was awarded the 2012 Nobel Prize along with Sir John Gurdon "for the discovery that mature cells can be reprogrammed to become pluripotent." [2]

Pluripotent stem cells hold great promise in the field of regenerative medicine. Because they can propagate indefinitely, as well as give rise to every other cell type in the body (such as neurons, heart, pancreatic, and liver cells), they represent a single source of cells that could be used to replace those lost to damage or disease.

The most well-known type of pluripotent stem cell is the embryonic stem cell. However, since the generation of embryonic stem cells involves destruction (or at least manipulation) [3] of the pre-implantation stage embryo, there has been much controversy surrounding their use. Further, because embryonic stem cells can only be derived from embryos, it has so far not been feasible to create patient-matched embryonic stem cell lines.

Since iPSCs can be derived directly from adult tissues, they not only bypass the need for embryos, but can be made in a patient-matched manner, which means that each individual could have their own pluripotent stem cell line. These unlimited supplies of autologous cells could be used to generate transplants without the risk of immune rejection. While the iPSC technology has not yet advanced to a stage where therapeutic transplants have been deemed safe, iPSCs are readily being used in personalized drug discovery efforts and understanding the patient-specific basis of disease.[citation needed]

Depending on the methods used, reprogramming of adult cells to obtain iPSCs may pose significant risks that could limit their use in humans. For example, if viruses are used to genomically alter the cells, the expression of oncogenes (cancer-causing genes) may potentially be triggered. In February 2008, scientists announced the discovery of a technique that could remove oncogenes after the induction of pluripotency, thereby increasing the potential use of iPS cells in human diseases.[4] In April 2009, it was demonstrated that generation of iPS cells is possible without any genetic alteration of the adult cell: a repeated treatment of the cells with certain proteins channeled into the cells via poly-arginine anchors was sufficient to induce pluripotency.[5] The acronym given for those iPSCs is piPSCs (protein-induced pluripotent stem cells).

iPSCs are typically derived by introducing a specific set of pluripotency-associated genes, or reprogramming factors, into a given cell type. The original set of reprogramming factors (also dubbed Yamanaka factors) are the genes Oct4 (Pou5f1), Sox2, cMyc, and Klf4. While this combination is most conventional in producing iPSCs, each of the factors can be functionally replaced by related transcription factors, miRNAs, small molecules, or even non-related genes such as lineage specifiers.

iPSC derivation is typically a slow and inefficient process, taking 12 weeks for mouse cells and 34 weeks for human cells, with efficiencies around 0.01%0.1%. However, considerable advances have been made in improving the efficiency and the time it takes to obtain iPSCs. Upon introduction of reprogramming factors, cells begin to form colonies that resemble pluripotent stem cells, which can be isolated based on their morphology, conditions that select for their growth, or through expression of surface markers or reporter genes.

Induced pluripotent stem cells were first generated by Shinya Yamanaka's team at Kyoto University, Japan, in 2006.[1] Their hypothesis was that genes important to embryonic stem cell function might be able to induce an embryonic state in adult cells. They began by choosing twenty-four genes that were previously identified as important in embryonic stem cells, and used retroviruses to deliver these genes to fibroblasts from mice. The mouse fibroblasts were engineered so that any cells that reactivated the ESC-specific gene, Fbx15, could be isolated using antibiotic selection.

Upon delivery of all twenty-four factors, colonies emerged that had reactivated the Fbx15 reporter, resembled ESCs, and could propagate indefinitely. They then narrowed their candidates by removing one factor at a time from the pool of twenty-four. By this process, they identified four factors, Oct4, Sox2, cMyc, and Klf4, which as a group were both necessary and sufficient to obtain ESC-like colonies under selection for reactivation of Fbx15.

Similar to ESCs, these first-generation iPSCs showed unlimited self-renewal and demonstrated pluripotency by contributing to lineages from all three germ layers in the context of embryoid bodies, teratomas, fetal chimeras. However, the molecular makeup of these cells, including gene expression and epigenetic marks, was somewhere between that of a fibroblast and an ESC, and the cells also failed to produce viable chimeras when injected into developing embryos.

In June 2007, the same group published a breakthrough study along with two other independent research groups from Harvard, MIT, and the University of California, Los Angeles, showing successful reprogramming of mouse fibroblasts into iPS cells. Unlike the first generation of iPS cells, these cells could produce viable chimeric mice and could contribute to the germline, the 'gold standard' for pluripotent stem cells. These cells were derived from mouse fibroblasts by retroviral-mediated expression of the same four transcription factors (Oct4, Sox2, cMyc, Klf4), but the researchers used a different marker to select for pluripotent cells. Instead of Fbx15, they used Nanog, a gene that is functionally important in ESCs. By using this different strategy, the researchers were able to create iPS cells that were more similar to ESCs than the first generation of iPS cells, and independently proved that it was possible to create iPS cells that are functionally identical to ESCs.[6][7][8][9]

Unfortunately, two of the four genes used (namely, c-Myc and KLF4) are oncogenic, and 20% of the chimeric mice developed cancer. In a later study, Yamanaka reported that one can create iPSCs even without c-Myc. The process takes longer and is not as efficient, but the resulting chimeras didn't develop cancer.[10]

Induced pluripotent cells have been made from adult stomach, liver, skin cells, blood cells, prostate cells and urinary tract cells.[11]

In November 2007, a milestone was achieved[12][13] by creating iPSCs from adult human cells; two independent research teams' studies were released one in Science by James Thomson at University of WisconsinMadison[14] and another in Cell by Shinya Yamanaka and colleagues at Kyoto University, Japan.[15] With the same principle used earlier in mouse models, Yamanaka had successfully transformed human fibroblasts into pluripotent stem cells using the same four pivotal genes: Oct3/4, Sox2, Klf4, and c-Myc with a retroviral system. Thomson and colleagues used OCT4, SOX2, NANOG, and a different gene LIN28 using a lentiviral system.

On 8 November 2012, researchers from Austria, Hong Kong and China presented a protocol for generating human iPSCs from exfoliated renal epithelial cells present in urine on Nature Protocols.[16] This method of acquiring donor cells is comparatively less invasive and simple. The team reported the induction procedure to take less time, around 2 weeks for the urinary cell culture and 3 to 4 weeks for the reprogramming; and higher yield, up to 4% using retroviral delivery of exogenous factors. Urinary iPSCs (UiPSCs) were found to show good differentiation potential, and thus represent an alternative choice for producing pluripotent cells from normal individuals or patients with genetic diseases, including those affecting the kidney.[16]

Although the methods pioneered by Yamanaka and others have demonstrated that adult cells can be reprogrammed to iPS cells, there are still challenges associated with this technology:

The table at right summarizes the key strategies and techniques used to develop iPS cells over the past half-decade. Rows of similar colors represents studies that used similar strategies for reprogramming.

One of the main strategies for avoiding problems (1) and (2) has been to use small compounds that can mimic the effects of transcription factors. These molecule compounds can compensate for a reprogramming factor that does not effectively target the genome or fails at reprogramming for another reason; thus they raise reprogramming efficiency. They also avoid the problem of genomic integration, which in some cases contributes to tumor genesis. Key studies using such strategy were conducted in 2008. Melton et al. studied the effects of histone deacetylase (HDAC) inhibitor valproic acid. They found that it increased reprogramming efficiency 100-fold (compared to Yamanakas traditional transcription factor method).[25] The researchers proposed that this compound was mimicking the signaling that is usually caused by the transcription factor c-Myc. A similar type of compensation mechanism was proposed to mimic the effects of Sox2. In 2008, Ding et al. used the inhibition of histone methyl transferase (HMT) with BIX-01294 in combination with the activation of calcium channels in the plasma membrane in order to increase reprogramming efficiency.[26] Deng et al. of Beijing University reported on July 2013 that induced pluripotent stem cells can be created without any genetic modification. They used a cocktail of seven small-molecule compounds including DZNep to induce the mouse somatic cells into stem cells which they called CiPS cells with the efficiency at 0.2% comparable to those using standard iPSC production techniques. The CiPS cells were introduced into developing mouse embryos and were found to contribute to all major cells types, proving its pluripotency.[27][28]

Ding et al. demonstrated an alternative to transcription factor reprogramming through the use of drug-like chemicals. By studying the MET (mesenchymal-epithelial transition) process in which fibroblasts are pushed to a stem-cell like state, Dings group identified two chemicals ALK5 inhibitor SB431412 and MEK (mitogen-activated protein kinase) inhibitor PD0325901 which was found to increase the efficiency of the classical genetic method by 100 fold. Adding a third compound known to be involved in the cell survival pathway, Thiazovivin further increases the efficiency by 200 fold. Using the combination of these three compounds also decreased the reprogramming process of the human fibroblasts from four weeks to two weeks. [29][30]

Another key strategy for avoiding problems such as tumor genesis and low throughput has been to use alternate forms of vectors: adenovirus, plasmids, and naked DNA and/or protein compounds.

In 2008, Hochedlinger et al. used an adenovirus to transport the requisite four transcription factors into the DNA of skin and liver cells of mice, resulting in cells identical to ESCs. The adenovirus is unique from other vectors like viruses and retroviruses because it does not incorporate any of its own genes into the targeted host and avoids the potential for insertional mutagenesis.[31] In 2009, Freed et al. demonstrated successful reprogramming of human fibroblasts to iPS cells.[32] Another advantage of using adenoviruses is that they only need to present for a brief amount of time in order for effective reprogramming to take place.

Also in 2008, Yamanaka et al. found that they could transfer the four necessary genes with a plasmid.[33] The Yamanaka group successfully reprogrammed mouse cells by transfection with two plasmid constructs carrying the reprogramming factors; the first plasmid expressed c-Myc, while the second expressed the other three factors (Oct4, Klf4, and Sox2). Although the plasmid methods avoid viruses, they still require cancer-promoting genes to accomplish reprogramming. The other main issue with these methods is that they tend to be much less efficient compared to retroviral methods. Furthermore, transfected plasmids have been shown to integrate into the host genome and therefore they still pose the risk of insertional mutagenesis. Because non-retroviral approaches have demonstrated such low efficiency levels, researchers have attempted to effectively rescue the technique with what is known as the piggyBac transposon system. The lifecycle of this system is shown below. Several studies have demonstrated that this system can effectively deliver the key reprogramming factors without leaving any footprint mutations in the host cell genome. As demonstrated in the figure, the piggyBac transposon system involves the re-excision of exogenous genes, which eliminates issues like insertional mutagenesis

In January 2014, two articles were published claiming that a type of pluripotent stem cell can be generated by subjecting the cells to certain types of stress (bacterial toxin, a low pH of 5.7, or physical squeezing); the resulting cells were called STAP cells, for stimulus-triggered acquisition of pluripotency.[34]

In light of difficulties that other labs had replicating the results of the surprising study, in March 2014, one of the co-authors has called for the articles to be retracted.[35] On 4 June 2014, the lead author, Obokata agreed to retract both the papers [36] after she was found to have committed research misconduct as concluded in an investigation by RIKEN on 1 April 2014.[37]

Studies by Blelloch et al. in 2009 demonstrated that expression of ES cell-specific microRNA molecules (such as miR-291, miR-294 and miR-295) enhances the efficiency of induced pluripotency by acting downstream of c-Myc .[38] More recently (in April 2011), Morrisey et al. demonstrated another method using microRNA that improved the efficiency of reprogramming to a rate similar to that demonstrated by Ding. MicroRNAs are short RNA molecules that bind to complementary sequences on messenger RNA and block expression of a gene. Morriseys team worked on microRNAs in lung development, and hypothesized that their microRNAs perhaps blocked expression of repressors of Yamanakas four transcription factors. Possible mechanisms by which microRNAs can induce reprogramming even in the absence of added exogenous transcription factors, and how variations in microRNA expression of iPS cells can predict their differentiation potential discussed by Xichen Bao et al.[39]

[citation needed]

The generation of iPS cells is crucially dependent on the genes used for the induction.

Oct-3/4 and certain members of the Sox gene family (Sox1, Sox2, Sox3, and Sox15) have been identified as crucial transcriptional regulators involved in the induction process whose absence makes induction impossible. Additional genes, however, including certain members of the Klf family (Klf1, Klf2, Klf4, and Klf5), the Myc family (c-myc, L-myc, and N-myc), Nanog, and LIN28, have been identified to increase the induction efficiency.

Induced pluripotent stem cells are similar to natural pluripotent stem cells, such as embryonic stem (ES) cells, in many aspects, such as the expression of certain stem cell genes and proteins, chromatin methylation patterns, doubling time, embryoid body formation, teratoma formation, viable chimera formation, and potency and differentiability, but the full extent of their relation to natural pluripotent stem cells is still being assessed.[42]

Gene expression and genome-wide H3K4me3 and H3K27me3 were found to be extremely similar between ES and iPS cells.[43][citation needed] The generated iPSCs were remarkably similar to naturally isolated pluripotent stem cells (such as mouse and human embryonic stem cells, mESCs and hESCs, respectively) in the following respects, thus confirming the identity, authenticity, and pluripotency of iPSCs to naturally isolated pluripotent stem cells:

Recent achievements and future tasks for safe iPSC-based cell therapy are collected in the review of Okano et al.[55]

The task of producing iPS cells continues to be challenging due to the six problems mentioned above. A key tradeoff to overcome is that between efficiency and genomic integration. Most methods that do not rely on the integration of transgenes are inefficient, while those that do rely on the integration of transgenes face the problems of incomplete reprogramming and tumor genesis, although a vast number of techniques and methods have been attempted. Another large set of strategies is to perform a proteomic characterization of iPS cells. The Wu group at Stanford University has made significant progress with this strategy.[56] Further studies and new strategies should generate optimal solutions to the five main challenges. One approach might attempt to combine the positive attributes of these strategies into an ultimately effective technique for reprogramming cells to iPS cells.

Another approach is the use of iPS cells derived from patients to identify therapeutic drugs able to rescue a phenotype. For instance, iPS cell lines derived from patients affected by ectodermal dysplasia syndrome (EEC), in which the p63 gene is mutated, display abnormal epithelial commitment that could be partially rescued by a small compound[57]

An attractive feature of human iPS cells is the ability to derive them from adult patients to study the cellular basis of human disease. Since iPS cells are self-renewing and pluripotent, they represent a theoretically unlimited source of patient-derived cells which can be turned into any type of cell in the body. This is particularly important because many other types of human cells derived from patients tend to stop growing after a few passages in laboratory culture. iPS cells have been generated for a wide variety of human genetic diseases, including common disorders such as Down syndrome and polycystic kidney disease.[58][59] In many instances, the patient-derived iPS cells exhibit cellular defects not observed in iPS cells from healthy patients, providing insight into the pathophysiology of the disease.[60] An international collaborated project, StemBANCC, was formed in 2012 to build a collection of iPS cell lines for drug screening for a variety of disease. Managed by the University of Oxford, the effort pooled funds and resources from 10 pharmaceutical companies and 23 universities. The goal is to generate a library of 1,500 iPS cell lines which will be used in early drug testing by providing a simulated human disease environment.[61]

A proof-of-concept of using induced pluripotent stem cells (iPSCs) to generate human organ for transplantation was reported by researchers from Japan. Human liver buds (iPSC-LBs) were grown from a mixture of three different kinds of stem cells: hepatocytes (for liver function) coaxed from iPSCs; endothelial stem cells (to form lining of blood vessels) from umbilical cord blood; and mesenchymal stem cells (to form connective tissue). This new approach allows different cell types to self-organize into a complex organ, mimicking the process in fetal development. After growing in vitro for a few days, the liver buds were transplanted into mice where the liver quickly connected with the host blood vessels and continued to grow. Most importantly, it performed regular liver functions including metabolizing drugs and producing liver-specific proteins. Further studies will monitor the longevity of the transplanted organ in the host body (ability to integrate or avoid rejection) and whether it will transform into tumors.[62][63] Using this method, cells from one mouse could be used to test 1,000 drug compounds to treat liver disease, and reduce animal use by up to 50,000.[64]

Embryonic cord-blood cells were induced into pluripotent stem cells using plasmid DNA. Using cell surface endothelial/pericytic markers CD31 and CD146, researchers identified 'vascular progenitor', the high-quality, multipotent vascular stem cells. After the iPS cells were injected directly into the vitreous of the damaged retina of mice, the stem cells engrafted into the retina, grew and repaired the vascular vessels.[65][66]

In a study conducted in China in 2013, Superparamagnetic iron oxide (SPIO) particles were used to label iPSCs-derived NSCs in vitro. Labeled NSCs were implanted into TBI rats and SCI monkeys 1 week after injury, and then imaged using gradient reflection echo (GRE) sequence by 3.0T magnetic resonance imaging (MRI) scanner. MRI analysis was performed at 1, 7, 14, 21, and 30 days, respectively, following cell transplantation. Pronounced hypointense signals were initially detected at the cell injection sites in rats and monkeys and were later found to extend progressively to the lesion regions, demonstrating that iPSCs-derived NSCs could migrate to the lesion area from the primary sites. The therapeutic efficacy of iPSCs-derived NSCs was examined concomitantly through functional recovery tests of the animals. In this study, we tracked iPSCs-derived NSCs migration in the CNS of TBI rats and SCI monkeys in vivo for the first time. Functional recovery tests showed obvious motor function improvement in transplanted animals. These data provide the necessary foundation for future clinical application of iPSCs for CNS injury.[67]

In 2014, type O red blood cells were synthesized at the Scottish National Blood Transfusion Service from iPSC. The cells were induced to become a mesoderm and then blood cells and then red blood cells. The final step was to make them eject their nuclei and mature properly. Type O can be transfused into all patients. Each pint of blood contains about two trillion red blood cells, while some 107 million blood donations are collected globally every year. Human transfusions were not expected to begin until 2016.[68]

The first human clinical trial using autologous iPSCs is approved by the Japan Ministry Health and will be conducted in 2014 in Kobe. iPSCs derived from skin cells from six patients suffering from wet age-related macular degeneration will be reprogrammed to differentiate into retinal pigment epithelial (RPE) cells. The cell sheet will be transplanted into the affected retina where the degenerated RPE tissue has been excised. Safety and vision restoration monitoring is expected to last one to three years.[69][70] The benefits of using autologous iPSCs are that there is theoretically no risk of rejection and it eliminates the need to use embryonic stem cells.[70]

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Induced pluripotent stem cell - Wikipedia, the free ...

IPS Cell Therapy Comments Off on Induced pluripotent stem cell – Wikipedia, the free … | October 24th, 2015

Endogenous cardiac stem cells (eCSCs) are tissue-specific stem progenitor cells harboured within the adult mammalian heart.

They were first discovered in 2003 by Bernardo Nadal-Ginard, Piero Anversa and colleagues [1][2] in the adult rat heart and since then have been identified and isolated from mouse, dog, porcine and human hearts.[3][4]

The adult heart was previously thought to be a post mitotic organ without any regenerative capability. The identification of eCSCs has provided an explanation for the hitherto unexplained existence of a subpopulation of immature cycling myocytes in the adult myocardium. Indeed, recent evidence from a genetic fate-mapping study established that stem cells replenish adult mammalian cardiomyocytes lost by cardiac wear and tear and injury throughout the adult life.[5] Moreover, it is now accepted that myocyte death and myocyte renewal are the two sides of the proverbial coin of cardiac homeostasis in which the eCSCs play a central role.[6] These findings produced a paradigm shift in cardiac biology and opened new opportunities and approaches for future treatment of cardiac diseases by placing the heart squarely amongst other organs with regenerative potential such as the liver, skin, muscle, CNS. However, they have not changed the well-established fact that the working myocardium is mainly constituted of terminally differentiated contractile myocytes. This fact does not exclude, but is it fully compatible with the heart being endowed with a robust intrinsic regenerative capacity which resides in the presence of the eCSCs throughout the individual lifespan.

Briefly, eCSCs have been first identified through the expression of c-kit, the receptor of the stem cell factor and the absence of common hematopoietic markers, like CD45. Afterwards, different membrane markers (Sca-1, Abcg-2, Flk-1) and transcription factors (Isl-1, Nkx2.5, GATA4) have been employed to identify and characterize these cells in the embryonic and adult life.[7] eCSCs are clonogenic, self renewing and multipotent in vitro and in vivo,[8] capable of generating the 3 major cell types of the myocardium: myocytes, smooth muscle and endothelial vascular cells.[9] They express several markers of stemness (i.e. Oct3/4, Bmi-1, Nanog) and have significant regenerative potential in vivo.[10] When cloned in suspension they form cardiospheres,[11] which when cultured in a myogenic differentiation medium, attach and differentiate into beating cardiomyocytes.

In 2012, it was proposed that Isl-1 is not a marker for endogenous cardiac stem cells.[12] That same year, a different group demonstrated that Isl-1 is not restricted to second heart field progenitors in the developing heart, but also labels cardiac neural crest.[13] It has also been reported that Flk-1 is not a specific marker for endogenous and mouse ESC-derived Isl1+ CPCs. While some eCSC discoveries have been brought into question, there has been success with other membrane markers. For instance, it was demonstrated that the combination of Flt1+/Flt4+ membrane markers identifies an Isl1+/Nkx2.5+ cell population in the developing heart. It was also shown that endogenous Flt1+/Flt4+ cells could be expanded in vitro and displayed trilineage differentiation potential. Flt1+/Flt4+ CPCs derived from iPSCs were shown to engraft into the adult myocardium and robustly differentiate into cardiomyocytes with phenotypic and electrophysiologic characteristics of adult cardiomyocytes.[14]

With the myocardium now recognized as a tissue with limited regenerating potential,[15] harbouring eCSCs that can be isolated and amplified in vitro [16] for regenerative protocols of cell transplantation or stimulated to replicate and differentiate in situ in response to growth factors,[17] it has become reasonable to exploit this endogenous regenerative potential to replace lost/damaged cardiac muscle with autologous functional myocardium.

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Cardiac Stem Cells Comments Off on Endogenous cardiac stem cell – Wikipedia, the free … | October 23rd, 2015

Hematopoietic stem cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood. It may be autologous (the patient's own stem cells are used) or allogeneic (the stem cells come from a donor). It is a medical procedure in the field of hematology, most often performed for patients with certain cancers of the blood or bone marrow, such as multiple myeloma or leukemia. In these cases, the recipient's immune system is usually destroyed with radiation or chemotherapy before the transplantation. Infection and graft-versus-host disease are major complications of allogeneic HSCT.

Hematopoietic stem cell transplantation remains a dangerous procedure with many possible complications; it is reserved for patients with life-threatening diseases. As survival following the procedure has increased, its use has expanded beyond cancer, such as autoimmune diseases.[1][2]

Indications for stem cell transplantation are as follows:

Many recipients of HSCTs are multiple myeloma[3] or leukemia patients[4] who would not benefit from prolonged treatment with, or are already resistant to, chemotherapy. Candidates for HSCTs include pediatric cases where the patient has an inborn defect such as severe combined immunodeficiency or congenital neutropenia with defective stem cells, and also children or adults with aplastic anemia[5] who have lost their stem cells after birth. Other conditions[6] treated with stem cell transplants include sickle-cell disease, myelodysplastic syndrome, neuroblastoma, lymphoma, Ewing's sarcoma, desmoplastic small round cell tumor, chronic granulomatous disease and Hodgkin's disease. More recently non-myeloablative, "mini transplant(microtransplantation)," procedures have been developed that require smaller doses of preparative chemo and radiation. This has allowed HSCT to be conducted in the elderly and other patients who would otherwise be considered too weak to withstand a conventional treatment regimen.

A total of 50,417 first hematopoietic stem cell transplants were reported as taking place worldwide in 2006, according to a global survey of 1327 centers in 71 countries conducted by the Worldwide Network for Blood and Marrow Transplantation. Of these, 28,901 (57 percent) were autologous and 21,516 (43 percent) were allogeneic (11,928 from family donors and 9,588 from unrelated donors). The main indications for transplant were lymphoproliferative disorders (54.5 percent) and leukemias (33.8 percent), and the majority took place in either Europe (48 percent) or the Americas (36 percent).[7] In 2009, according to the World Marrow Donor Association, stem cell products provided for unrelated transplantation worldwide had increased to 15,399 (3,445 bone marrow donations, 8,162 peripheral blood stem cell donations, and 3,792 cord blood units).[8]

Autologous HSCT requires the extraction (apheresis) of haematopoietic stem cells (HSC) from the patient and storage of the harvested cells in a freezer. The patient is then treated with high-dose chemotherapy with or without radiotherapy with the intention of eradicating the patient's malignant cell population at the cost of partial or complete bone marrow ablation (destruction of patient's bone marrow function to grow new blood cells). The patient's own stored stem cells are then transfused into his/her bloodstream, where they replace destroyed tissue and resume the patient's normal blood cell production. Autologous transplants have the advantage of lower risk of infection during the immune-compromised portion of the treatment since the recovery of immune function is rapid. Also, the incidence of patients experiencing rejection (graft-versus-host disease) is very rare due to the donor and recipient being the same individual. These advantages have established autologous HSCT as one of the standard second-line treatments for such diseases as lymphoma.[9]

However, for others cancers such as acute myeloid leukemia, the reduced mortality of the autogenous relative to allogeneic HSCT may be outweighed by an increased likelihood of cancer relapse and related mortality, and therefore the allogeneic treatment may be preferred for those conditions.[10] Researchers have conducted small studies using non-myeloablative hematopoietic stem cell transplantation as a possible treatment for type I (insulin dependent) diabetes in children and adults. Results have been promising; however, as of 2009[update] it was premature to speculate whether these experiments will lead to effective treatments for diabetes.[11]

Allogeneics HSCT involves two people: the (healthy) donor and the (patient) recipient. Allogeneic HSC donors must have a tissue (HLA) type that matches the recipient. Matching is performed on the basis of variability at three or more loci of the HLA gene, and a perfect match at these loci is preferred. Even if there is a good match at these critical alleles, the recipient will require immunosuppressive medications to mitigate graft-versus-host disease. Allogeneic transplant donors may be related (usually a closely HLA matched sibling), syngeneic (a monozygotic or 'identical' twin of the patient - necessarily extremely rare since few patients have an identical twin, but offering a source of perfectly HLA matched stem cells) or unrelated (donor who is not related and found to have very close degree of HLA matching). Unrelated donors may be found through a registry of bone marrow donors such as the National Marrow Donor Program. People who would like to be tested for a specific family member or friend without joining any of the bone marrow registry data banks may contact a private HLA testing laboratory and be tested with a mouth swab to see if they are a potential match.[12] A "savior sibling" may be intentionally selected by preimplantation genetic diagnosis in order to match a child both regarding HLA type and being free of any obvious inheritable disorder. Allogeneic transplants are also performed using umbilical cord blood as the source of stem cells. In general, by transfusing healthy stem cells to the recipient's bloodstream to reform a healthy immune system, allogeneic HSCTs appear to improve chances for cure or long-term remission once the immediate transplant-related complications are resolved.[13][14][15]

A compatible donor is found by doing additional HLA-testing from the blood of potential donors. The HLA genes fall in two categories (Type I and Type II). In general, mismatches of the Type-I genes (i.e. HLA-A, HLA-B, or HLA-C) increase the risk of graft rejection. A mismatch of an HLA Type II gene (i.e. HLA-DR, or HLA-DQB1) increases the risk of graft-versus-host disease. In addition a genetic mismatch as small as a single DNA base pair is significant so perfect matches require knowledge of the exact DNA sequence of these genes for both donor and recipient. Leading transplant centers currently perform testing for all five of these HLA genes before declaring that a donor and recipient are HLA-identical.

Race and ethnicity are known to play a major role in donor recruitment drives, as members of the same ethnic group are more likely to have matching genes, including the genes for HLA.[16]

As of 2013[update], there were at least two commercialized allogeneic cell therapies, Prochymal and Cartistem.[17]

To limit the risks of transplanted stem cell rejection or of severe graft-versus-host disease in allogeneic HSCT, the donor should preferably have the same human leukocyte antigens (HLA) as the recipient. About 25 to 30 percent of allogeneic HSCT recipients have an HLA-identical sibling. Even so-called "perfect matches" may have mismatched minor alleles that contribute to graft-versus-host disease.

In the case of a bone marrow transplant, the HSC are removed from a large bone of the donor, typically the pelvis, through a large needle that reaches the center of the bone. The technique is referred to as a bone marrow harvest and is performed under general anesthesia.

Peripheral blood stem cells[18] are now the most common source of stem cells for allogeneic HSCT. They are collected from the blood through a process known as apheresis. The donor's blood is withdrawn through a sterile needle in one arm and passed through a machine that removes white blood cells. The red blood cells are returned to the donor. The peripheral stem cell yield is boosted with daily subcutaneous injections of Granulocyte-colony stimulating factor, serving to mobilize stem cells from the donor's bone marrow into the peripheral circulation.

It is also possible to extract stem cells from amniotic fluid for both autologous or heterologous use at the time of childbirth.

Umbilical cord blood is obtained when a mother donates her infant's umbilical cord and placenta after birth. Cord blood has a higher concentration of HSC than is normally found in adult blood. However, the small quantity of blood obtained from an Umbilical Cord (typically about 50 mL) makes it more suitable for transplantation into small children than into adults. Newer techniques using ex-vivo expansion of cord blood units or the use of two cord blood units from different donors allow cord blood transplants to be used in adults.

Cord blood can be harvested from the Umbilical Cord of a child being born after preimplantation genetic diagnosis (PGD) for human leucocyte antigen (HLA) matching (see PGD for HLA matching) in order to donate to an ill sibling requiring HSCT.

Unlike other organs, bone marrow cells can be frozen (cryopreserved) for prolonged periods without damaging too many cells. This is a necessity with autologous HSC because the cells must be harvested from the recipient months in advance of the transplant treatment. In the case of allogeneic transplants, fresh HSC are preferred in order to avoid cell loss that might occur during the freezing and thawing process. Allogeneic cord blood is stored frozen at a cord blood bank because it is only obtainable at the time of childbirth. To cryopreserve HSC, a preservative, DMSO, must be added, and the cells must be cooled very slowly in a controlled-rate freezer to prevent osmotic cellular injury during ice crystal formation. HSC may be stored for years in a cryofreezer, which typically uses liquid nitrogen.

The chemotherapy or irradiation given immediately prior to a transplant is called the conditioning regimen, the purpose of which is to help eradicate the patient's disease prior to the infusion of HSC and to suppress immune reactions. The bone marrow can be ablated (destroyed) with dose-levels that cause minimal injury to other tissues. In allogeneic transplants a combination of cyclophosphamide with total body irradiation is conventionally employed. This treatment also has an immunosuppressive effect that prevents rejection of the HSC by the recipient's immune system. The post-transplant prognosis often includes acute and chronic graft-versus-host disease that may be life-threatening. However, in certain leukemias this can coincide with protection against cancer relapse owing to the graft versus tumor effect.[19]Autologous transplants may also use similar conditioning regimens, but many other chemotherapy combinations can be used depending on the type of disease.

A newer treatment approach, non-myeloablative allogeneic transplantation, also termed reduced-intensity conditioning (RIC), uses doses of chemotherapy and radiation too low to eradicate all the bone marrow cells of the recipient.[20]:320321 Instead, non-myeloablative transplants run lower risks of serious infections and transplant-related mortality while relying upon the graft versus tumor effect to resist the inherent increased risk of cancer relapse.[21][22] Also significantly, while requiring high doses of immunosuppressive agents in the early stages of treatment, these doses are less than for conventional transplants.[23] This leads to a state of mixed chimerism early after transplant where both recipient and donor HSC coexist in the bone marrow space.

Decreasing doses of immunosuppressive therapy then allows donor T-cells to eradicate the remaining recipient HSC and to induce the graft versus tumor effect. This effect is often accompanied by mild graft-versus-host disease, the appearance of which is often a surrogate marker for the emergence of the desirable graft versus tumor effect, and also serves as a signal to establish an appropriate dosage level for sustained treatment with low levels of immunosuppressive agents.

Because of their gentler conditioning regimens, these transplants are associated with a lower risk of transplant-related mortality and therefore allow patients who are considered too high-risk for conventional allogeneic HSCT to undergo potentially curative therapy for their disease. The optimal conditioning strategy for each disease and recipient has not been fully established, but RIC can be used in elderly patients unfit for myeloablative regimens, for whom a higher risk of cancer relapse may be acceptable.[20][22]

After several weeks of growth in the bone marrow, expansion of HSC and their progeny is sufficient to normalize the blood cell counts and re-initiate the immune system. The offspring of donor-derived hematopoietic stem cells have been documented to populate many different organs of the recipient, including the heart, liver, and muscle, and these cells had been suggested to have the abilities of regenerating injured tissue in these organs. However, recent research has shown that such lineage infidelity does not occur as a normal phenomenon[citation needed].

HSCT is associated with a high treatment-related mortality in the recipient (1 percent or higher)[citation needed], which limits its use to conditions that are themselves life-threatening. Major complications are veno-occlusive disease, mucositis, infections (sepsis), graft-versus-host disease and the development of new malignancies.

Bone marrow transplantation usually requires that the recipient's own bone marrow be destroyed ("myeloablation"). Prior to "engraftment" patients may go for several weeks without appreciable numbers of white blood cells to help fight infection. This puts a patient at high risk of infections, sepsis and septic shock, despite prophylactic antibiotics. However, antiviral medications, such as acyclovir and valacyclovir, are quite effective in prevention of HSCT-related outbreak of herpetic infection in seropositive patients.[24] The immunosuppressive agents employed in allogeneic transplants for the prevention or treatment of graft-versus-host disease further increase the risk of opportunistic infection. Immunosuppressive drugs are given for a minimum of 6-months after a transplantation, or much longer if required for the treatment of graft-versus-host disease. Transplant patients lose their acquired immunity, for example immunity to childhood diseases such as measles or polio. For this reason transplant patients must be re-vaccinated with childhood vaccines once they are off immunosuppressive medications.

Severe liver injury can result from hepatic veno-occlusive disease (VOD). Elevated levels of bilirubin, hepatomegaly and fluid retention are clinical hallmarks of this condition. There is now a greater appreciation of the generalized cellular injury and obstruction in hepatic vein sinuses, and hepatic VOD has lately been referred to as sinusoidal obstruction syndrome (SOS). Severe cases of SOS are associated with a high mortality rate. Anticoagulants or defibrotide may be effective in reducing the severity of VOD but may also increase bleeding complications. Ursodiol has been shown to help prevent VOD, presumably by facilitating the flow of bile.

The injury of the mucosal lining of the mouth and throat is a common regimen-related toxicity following ablative HSCT regimens. It is usually not life-threatening but is very painful, and prevents eating and drinking. Mucositis is treated with pain medications plus intravenous infusions to prevent dehydration and malnutrition.

Graft-versus-host disease (GVHD) is an inflammatory disease that is unique to allogeneic transplantation. It is an attack of the "new" bone marrow's immune cells against the recipient's tissues. This can occur even if the donor and recipient are HLA-identical because the immune system can still recognize other differences between their tissues. It is aptly named graft-versus-host disease because bone marrow transplantation is the only transplant procedure in which the transplanted cells must accept the body rather than the body accepting the new cells. Acute graft-versus-host disease typically occurs in the first 3 months after transplantation and may involve the skin, intestine, or the liver. High-dose corticosteroids such as prednisone are a standard treatment; however this immuno-suppressive treatment often leads to deadly infections. Chronic graft-versus-host disease may also develop after allogeneic transplant. It is the major source of late treatment-related complications, although it less often results in death. In addition to inflammation, chronic graft-versus-host disease may lead to the development of fibrosis, or scar tissue, similar to scleroderma; it may cause functional disability and require prolonged immunosuppressive therapy. Graft-versus-host disease is usually mediated by T cells, which react to foreign peptides presented on the MHC of the host[citation needed].

Graft versus tumor effect (GVT) or "graft versus leukemia" effect is the beneficial aspect of the Graft-versus-Host phenomenon. For example, HSCT patients with either acute, or in particular chronic, graft-versus-host disease after an allogeneic transplant tend to have a lower risk of cancer relapse.[25][26] This is due to a therapeutic immune reaction of the grafted donor T lymphocytes against the diseased bone marrow of the recipient. This lower rate of relapse accounts for the increased success rate of allogeneic transplants, compared to transplants from identical twins, and indicates that allogeneic HSCT is a form of immunotherapy. GVT is the major benefit of transplants that do not employ the highest immuno-suppressive regimens.

Graft versus tumor is mainly beneficial in diseases with slow progress, e.g. chronic leukemia, low-grade lymphoma, and some cases multiple myeloma. However, it is less effective in rapidly growing acute leukemias.[27]

If cancer relapses after HSCT, another transplant can be performed, infusing the patient with a greater quantity of donor white blood cells (Donor lymphocyte infusion).[27]

Patients after HSCT are at a higher risk for oral carcinoma. Post-HSCT oral cancer may have more aggressive behavior with poorer prognosis, when compared to oral cancer in non-HSCT patients.[28]

Prognosis in HSCT varies widely dependent upon disease type, stage, stem cell source, HLA-matched status (for allogeneic HCST) and conditioning regimen. A transplant offers a chance for cure or long-term remission if the inherent complications of graft versus host disease, immuno-suppressive treatments and the spectrum of opportunistic infections can be survived.[13][14] In recent years, survival rates have been gradually improving across almost all populations and sub-populations receiving transplants.[29]

Mortality for allogeneic stem cell transplantation can be estimated using the prediction model created by Sorror et al.,[30] using the Hematopoietic Cell Transplantation-Specific Comorbidity Index (HCT-CI). The HCT-CI was derived and validated by investigators at the Fred Hutchinson Cancer Research Center (Seattle, WA). The HCT-CI modifies and adds to a well-validated comorbidity index, the Charlson Comorbidity Index (CCI) (Charlson et al.[31]) The CCI was previously applied to patients undergoing allogeneic HCT but appears to provide less survival prediction and discrimination than the HCT-CI scoring system.

The risks of a complication depend on patient characteristics, health care providers and the apheresis procedure, and the colony-stimulating factor used (G-CSF). G-CSF drugs include filgrastim (Neupogen, Neulasta), and lenograstim (Graslopin).

Filgrastim is typically dosed in the 10 microgram/kg level for 45 days during the harvesting of stem cells. The documented adverse effects of filgrastim include splenic rupture (indicated by left upper abdominal or shoulder pain, risk 1 in 40000), Adult respiratory distress syndrome (ARDS), alveolar hemorrage, and allergic reactions (usually expressed in first 30 minutes, risk 1 in 300).[32][33][34] In addition, platelet and hemoglobin levels dip post-procedure, not returning to normal until one month.[34]

The question of whether geriatrics (patients over 65) react the same as patients under 65 has not been sufficiently examined. Coagulation issues and inflammation of atherosclerotic plaques are known to occur as a result of G-CSF injection.[33] G-CSF has also been described to induce genetic changes in mononuclear cells of normal donors.[33] There is evidence that myelodysplasia (MDS) or acute myeloid leukaemia (AML) can be induced by GCSF in susceptible individuals.[35]

Blood was drawn peripherally in a majority of patients, but a central line to jugular/subclavian/femoral veins may be used in 16 percent of women and 4 percent of men. Adverse reactions during apheresis were experienced in 20 percent of women and 8 percent of men, these adverse events primarily consisted of numbness/tingling, multiple line attempts, and nausea.[34]

A study involving 2408 donors (1860 years) indicated that bone pain (primarily back and hips) as a result of filgrastim treatment is observed in 80 percent of donors by day 4 post-injection.[34] This pain responded to acetaminophen or ibuprofen in 65 percent of donors and was characterized as mild to moderate in 80 percent of donors and severe in 10 percent.[34] Bone pain receded post-donation to 26 percent of patients 2 days post-donation, 6 percent of patients one week post-donation, and <2 percent 1 year post-donation. Donation is not recommended for those with a history of back pain.[34] Other symptoms observed in more than 40 percent of donors include myalgia, headache, fatigue, and insomnia.[34] These symptoms all returned to baseline 1 month post-donation, except for some cases of persistent fatigue in 3 percent of donors.[34]

In one metastudy that incorporated data from 377 donors, 44 percent of patients reported having adverse side effects after peripheral blood HSCT.[35] Side effects included pain prior to the collection procedure as a result of GCSF injections, post-procedural generalized skeletal pain, fatigue and reduced energy.[35]

A study that surveyed 2408 donors found that serious adverse events (requiring prolonged hospitalization) occurred in 15 donors (at a rate of 0.6 percent), although none of these events were fatal.[34] Donors were not observed to have higher than normal rates of cancer with up to 48 years of follow up.[34] One study based on a survey of medical teams covered approximately 24,000 peripheral blood HSCT cases between 1993 and 2005, and found a serious cardiovascular adverse reaction rate of about 1 in 1500.[33] This study reported a cardiovascular-related fatality risk within the first 30 days HSCT of about 2 in 10000. For this same group, severe cardiovascular events were observed with a rate of about 1 in 1500. The most common severe adverse reactions were pulmonary edema/deep vein thrombosis, splenic rupture, and myocardial infarction. Haematological malignancy induction was comparable to that observed in the general population, with only 15 reported cases within 4 years.[33]

Georges Math, a French oncologist, performed the first European bone marrow transplant in November 1958 on five Yugoslavian nuclear workers whose own marrow had been damaged by irradiation caused by a criticality accident at the Vina Nuclear Institute, but all of these transplants were rejected.[36][37][38][39][40] Math later pioneered the use of bone marrow transplants in the treatment of leukemia.[40]

Stem cell transplantation was pioneered using bone-marrow-derived stem cells by a team at the Fred Hutchinson Cancer Research Center from the 1950s through the 1970s led by E. Donnall Thomas, whose work was later recognized with a Nobel Prize in Physiology or Medicine. Thomas' work showed that bone marrow cells infused intravenously could repopulate the bone marrow and produce new blood cells. His work also reduced the likelihood of developing a life-threatening complication called graft-versus-host disease.[41]

The first physician to perform a successful human bone marrow transplant on a disease other than cancer was Robert A. Good at the University of Minnesota in 1968.[42] In 1975, John Kersey, M.D., also of the University of Minnesota, performed the first successful bone marrow transplant to cure lymphoma. His patient, a 16-year-old-boy, is today the longest-living lymphoma transplant survivor.[43]

At the end of 2012, 20.2 million people had registered their willingness to be a bone marrow donor with one of the 67 registries from 49 countries participating in Bone Marrow Donors Worldwide. 17.9 million of these registered donors had been ABDR typed, allowing easy matching. A further 561,000 cord blood units had been received by one of 46 cord blood banks from 30 countries participating. The highest total number of bone marrow donors registered were those from the USA (8.0 million), and the highest number per capita were those from Cyprus (15.4 percent of the population).[44]

Within the United States, racial minority groups are the least likely to be registered and therefore the least likely to find a potentially life-saving match. In 1990, only six African-Americans were able to find a bone marrow match, and all six had common European genetic signatures.[45]

Africans are more genetically diverse than people of European descent, which means that more registrations are needed to find a match. Bone marrow and cord blood banks exist in South Africa, and a new program is beginning in Nigeria.[45] Many people belonging to different races are requested to donate as there is a shortage of donors in African, Mixed race, Latino, Aboriginal, and many other communities.

In 2007, a team of doctors in Berlin, Germany, including Gero Htter, performed a stem cell transplant for leukemia patient Timothy Ray Brown, who was also HIV-positive.[46] From 60 matching donors, they selected a [CCR5]-32 homozygous individual with two genetic copies of a rare variant of a cell surface receptor. This genetic trait confers resistance to HIV infection by blocking attachment of HIV to the cell. Roughly one in 1000 people of European ancestry have this inherited mutation, but it is rarer in other populations.[47][48] The transplant was repeated a year later after a leukemia relapse. Over three years after the initial transplant, and despite discontinuing antiretroviral therapy, researchers cannot detect HIV in the transplant recipient's blood or in various biopsies of his tissues.[49] Levels of HIV-specific antibodies have also declined, leading to speculation that the patient may have been functionally cured of HIV. However, scientists emphasise that this is an unusual case.[50] Potentially fatal transplant complications (the "Berlin patient" suffered from graft-versus-host disease and leukoencephalopathy) mean that the procedure could not be performed in others with HIV, even if sufficient numbers of suitable donors were found.[51][52]

In 2012, Daniel Kuritzkes reported results of two stem cell transplants in patients with HIV. They did not, however, use donors with the 32 deletion. After their transplant procedures, both were put on antiretroviral therapies, during which neither showed traces of HIV in their blood plasma and purified CD4 T cells using a sensitive culture method (less than 3 copies/mL). However, the virus was once again detected in both patients some time after the discontinuation of therapy.[53]

Since McAllister's 1997 report on a patient with multiple sclerosis (MS) who received a bone marrow transplant for CML,[54] there have been over 600 reports of HSCTs performed primarily for MS.[55] These have been shown to "reduce or eliminate ongoing clinical relapses, halt further progression, and reduce the burden of disability in some patients" that have aggressive highly active MS, "in the absence of chronic treatment with disease-modifying agents".[55]

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Gene therapy and cell therapy are overlapping fields of biomedical research with the goals of repairing the direct cause of genetic diseases in the DNA or cellular population, respectively. These powerful strategies are also being focused on modulating specific genes and cell subpopulations in acquired diseases in order to reestablish the normal equilibrium. In many diseases, gene and cell therapy are combined in the development of promising therapies.

In addition, these two fields have helped provide reagents, concepts, and techniques that are elucidating the finer points of gene regulation, stem cell lineage, cell-cell interactions, feedback loops, amplification loops, regenerative capacity, and remodeling.

Gene therapy is defined as a set of strategies that modify the expression of an individuals genes or that correct abnormal genes. Each strategy involves the administration of a specific DNA (or RNA).

Cell therapy is defined as the administration of live whole cells or maturation of a specific cell population in a patient for the treatment of a disease.

Gene therapy: Historically, the discovery of recombinant DNA technology in the 1970s provided the tools to efficiently develop gene therapy. Scientists used these techniques to readily manipulate viral genomes, isolate genes, identify mutations involved in human diseases, characterize and regulate gene expression, and engineer various viral vectors and non-viral vectors. Many vectors, regulatory elements, and means of transfer into animals have been tried. Taken together, the data show that each vector and set of regulatory elements provides specific expression levels and duration of expression. They exhibit an inherent tendency to bind and enter specific types of cells as well as spread into adjacent cells. The effect of the vectors and regulatory elements are able to be reproduced on adjacent genes. The effect also has a predictable survival length in the host. Although the route of administration modulates the immune response to the vector, each vector has a relatively inherent ability, whether low, medium or high, to induce an immune response to the transduced cells and the new gene products.

The development of suitable gene therapy treatments for many genetic diseases and some acquired diseases has encountered many challenges and uncovered new insights into gene interactions and regulation. Further development often involves uncovering basic scientific knowledge of the affected tissues, cells, and genes, as well as redesigning vectors, formulations, and regulatory cassettes for the genes.

While effective long-term treatments for anemias, hemophilia, cystic fibrosis, muscular dystrophy, Gauschers disease, lysosomal storage diseases, cardiovascular diseases, diabetes, and diseases of the bones and joints are elusive today, some success is being observed in the treatment of several types of immunodeficiency diseases, cancer, and eye disorders. Further details on the status of development of gene therapy for specific diseases are summarized here.

Cell therapy: Historically, blood transfusions were the first type of cell therapy and are now considered routine. Bone marrow transplantation has also become a well-established protocol. Bone marrow transplantation is the treatment of choice for many kinds of blood disorders, including anemias, leukemias, lymphomas, and rare immunodeficiency diseases. The key to successful bone marrow transplantation is the identification of a good "immunologically matched" donor, who is usually a close relative, such as a sibling. After finding a good match between the donors and recipients cells, the bone marrow cells of the patient (recipient) are destroyed by chemotherapy or radiation to provide room in the bone marrow for the new cells to reside. After the bone marrow cells from the matched donor are infused, the self-renewing stem cells find their way to the bone marrow and begin to replicate. They also begin to produce cells that mature into the various types of blood cells. Normal numbers of donor-derived blood cells usually appear in the circulation of the patient within a few weeks. Unfortunately, not all patients have a good immunological matched donor. Furthermore, bone marrow grafts may fail to fully repopulate the bone marrow in as many as one third of patients, and the destruction of the host bone marrow can be lethal, particularly in very ill patients. These requirements and risks restrict the utility of bone marrow transplantation to some patients.

Cell therapy is expanding its repertoire of cell types for administration. Cell therapy treatment strategies include isolation and transfer of specific stem cell populations, administration of effector cells, induction of mature cells to become pluripotent cells, and reprogramming of mature cells. Administration of large numbers of effector cells has benefited cancer patients, transplant patients with unresolved infections, and patients with chemically destroyed stem cells in the eye. For example, a few transplant patients cant resolve adenovirus and cytomegalovirus infections. A recent phase I trial administered a large number of T cells that could kill virally-infected cells to these patients. Many of these patients resolved their infections and retained immunity against these viruses. As a second example, chemical exposure can damage or cause atrophy of the limbal epithelial stem cells of the eye. Their death causes pain, light sensitivity, and cloudy vision. Transplantation of limbal epithelial stem cells for treatment of this deficiency is the first cell therapy for ocular diseases in clinical practice.

Several diseases benefit most from treatments that combine the technologies of gene and cell therapy. For example, some patients have a severe combined immunodeficiency disease (SCID) but unfortunately, do not have a suitable donor of bone marrow. Scientists have identified that patients with SCID are deficient in adenosine deaminase gene (ADA-SCID), or the common gamma chain located on the X chromosome (X-linked SCID). Several dozen patients have been treated with a combined gene and cell therapy approach. Each individuals hematopoietic stem cells were treated with a viral vector that expressed a copy of the relevant normal gene. After selection and expansion, these corrected stem cells were returned to the patients. Many patients improved and required less exogenous enzymes. However, some serious adverse events did occur and their incidence is prompting development of theoretically safer vectors and protocols. The combined approach also is pursued in several cancer therapies.

Further information on the progress and status of gene therapy and cell therapy on various diseases is listed here.

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Uncategorized Comments Off on Gene Therapy and Cell Therapy Defined | ASGCT – American … | October 20th, 2015

OK, so now we know the problem. There are certain genes needed to make a cell turn into an ES cell. Since these genes are presumably off in a skin cell, we need to turn them on again. And have all of the skin cell genes shut off too.

The way the scientists decided to do this was to add back whatever genes are needed to erase the pattern in the skin cell. (These genes are off in a skin cell.) This is a lot easier than specifically turning on this small set of genes.

The way they decided to add back the genes was with a virus. A lot of gene therapy gets done this way.

Many viruses work by sticking themselves into a cell's DNA. What the scientists planned to do was to take out some of the nonessential virus DNA and put in the necessary genes.

We're all set except we don't yet have the genes. Scientists had figured out through various means that if they added 24 different genes to a skin cell, it would turn into an ES cell. Yikes!

That is way too many to do gene therapy. So they started taking one away at a time to find the really key ones. They finally settled on 4 genes. This is still an awful lot but it is at least doable.

Last year they added back these genes and got some promising results. The skin cells took on many of the properties of ES cells but not all of them. This is encouraging but not good enough.

To fix this, they changed the skin cells to make selecting the most ES-like ones easier to do. When they did this, they were able to grow cells that essentially looked like an ES cell.

As a final test, they added some of these cells to an early mouse embryo. The embryo grew into a pup that contained different cell types derived from the original embryo and the skin cells (a chimera). This test proved these cells had been turned into something that could be used as ES cells.

Cool. But it is not a slam dunk to get this to work in people. We don't know if these same 4 genes are the ones that work in people too. And around 20% of the mice died from cancers caused by one of the added genes.

But these are problems we can deal with. Of course we'll have to continue to use "real" ES cells to figure out the genes needed to turn skin cells into ES cells. In other words, we need to destroy embryos now to stop destroying them in the future.

This research will progress very quickly. Because the experiments are easier to do than cloning, little labs all over the world can tackle these kinds of questions with no government interference. Personalized medicine may be here sooner than we think.

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Skin Stem Cells Comments Off on Embryonic stem cells from skin cells | Understanding Genetics | October 16th, 2015

As many of you know, the pioneering, first of its kind IPSC clinical study in Japan has been suspended as I first blogged about here.

In the comments section of that blog post there has been a helpful overall discussion that has involved Dr. Masayo Takahashi, the leader of the trial. It is great that Dr. Takahashi has been participating in this discussion and I commend her for that openness.

This comment stream has been particularly important because the media have only minimally reported on this important development. There have been only a few articles in Japanese (several months ago) and as far as I know only one in English, which was posted in the last day or so in The New Scientist. Unfortunately The New Scientist article, as many have noted here, used an inflammatory title invoking a supposed cancer scare and some over-the-top language. Although that article had some bits of important info, the negative bias in the article made it overall not very helpful. Some readers of that article were likely confused by how it was written and the title.

The clinical study in question is for macular degeneration and involves the use of sheets of retinal pigmented epithelial cells (RPE) made from IPSC (e.g. see image above from RIKEN).Several of us have been discussing the suspension of this trial over on Twitter too including Dr. Takahashi (@masayomasayo). Some tweets by the community have been constructive. Others not so much.

Two main possible issues have come up in the discussion of the reasons for the trial stopping: (1) six mutations were detected in the 2nd patients IPSC and (2) significant regulatory changes are on the way in Japan that apparently in some way will delimit IPSC research there. Dr. Takahashi has indicated that the latter reason was the dominant factor in their decision to suspend the trial. The fact that the 2nd patients IPSC reportedly had six mutations that were not present in the original somatic cells warrantsfurther discussion too. For example, when and how did these mutations arise? To be clear, however, I do not see (based on the information available) that there was a cancer scare by any stretch of the imagination as The New Scientist article had indicated.

At some point a restarted version of this study will likely focus on allogeneic use of IPSC perhaps via an IPSC bank being developed by Dr. Shinya Yamanaka. For many years the consensus, most exciting aspect of IPSCs in the field was considered to be their potential for use as the basis for powerful patient-specific autologous therapies. The apparent planned shift to non-autologous clinical use of IPSC in this case raises the question of how it would be superior or substantially different to the use of hESC, other than that making IPSC does not involve the use of a leftover IVF embryo.

This development also raises a 2nd question as to whether there will be a domino effect now of other clinical studies or trials that are in the works using IPSC switching to allogeneic paths as well. In other words, is this a historic, turning point moment for the IPSC field in Japan overall away from an autologous path?Or is the switch here to allogeneic just a one time, one study decision? More info on the regulatory changes is needed to help clarify the answer to this question and the path forward as well.

Hopefully the regulatory body in Japan (Ministry of Education?) that has made or is making the relevant regulatory changes will announce them publicly in detail soon. If that information is already out there (e.g. in Japanese on the web) perhaps someone can find it and well post it here.

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IPS Cell Therapy Comments Off on Historic turning point for IPS cell field in Japan … | October 16th, 2015

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CTRM provides services to develop and manufacture novel cellular therapy.

The Cell Therapy and Regenerative Medicine Program (CTRM) at the University of Utah provides the safest, highest quality products for therapeutic use and research. Our goals are to facilitate the availability of cellular and tissue based therapies to patients by bridging efforts in basic research, bioengineering and the medical sciences. As well as assemble the expertise and infrastructure to address the complex regulatory, financial and manufacturing challenges associated with delivering cell and tissue based products to patients.

To support hematopoietic stem cell transplants and to deliver innovative cellular and tissue engineered products to patients by providing comprehensive bench to bedside services that coordinate the efforts of clinicians, researchers, and bioengineers.

Product quality, safety and efficacy; Optimization of resource utilization; Promotion of productive collaborations; Support of innovative products; and Adherence to scientific and ethical excellence.

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Corresponding Author: Joshua M. Hare, MD, The Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Biomedical Research Bldg/Room 908, PO Box 016960 (R-125), Miami, FL 33101 (jhare@med.miami.edu).

Published Online: November 6, 2012. doi:10.1001/jama.2012.25321

Author Contributions:Dr Hare had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Hare, Gerstenblith, DiFede Velazquez, George, Mendizabal, McNiece, Heldman.

Acquisition of data: Hare, Fishman, Gerstenblith, DiFede Velazquez, Zambrano, Suncion, Tracy, Johnston, Brinker, Breton, Davis-Sproul, Byrnes, George, Lardo, Mendizabal, Lowery, Wong Po Foo, Ruiz, Amador, Da Silva, McNiece, Heldman.

Analysis and interpretation of data: Hare, Fishman, Zambrano, Suncion, Tracy, Ghersin, Lardo, Schulman, Mendizabal, Altman, Ruiz, Amador, Da Silva, McNiece, Heldman.

Drafting of the manuscript: Hare, Fishman, Ghersin, Mendizabal, Ruiz, Amador, Heldman.

Critical revision of the manuscript for important intellectual content: Hare, Fishman, Gerstenblith, DiFede Velazquez, Suncion, Tracy, Johnston, Brinker, Breton, Davis-Sproul, Schulman, Byrnes, Geroge, Lardo, Mendizabal, Lowery, Rouy, Altman, Wong Po Foo, Ruiz, Da Silva, McNiece, Heldman.

Statistical analysis: Hare, Mendizabal, McNiece, Heldman.

Obtained funding: Hare, Lardo.

Administrative, technical, or material support: Hare, DiFede Velazquez, Zambrano, Suncion, Ghersin, Johnston, Breton, Davis-Sproul, Schulman, Byrnes, Lowery, Rouy, Altman, Wong Po Foo, Da Silva, McNiece, Heldman.

Study supervision: Hare, Fishman, Gerstenblith, Tracy, George, Schulman, Altman, Da Silva, McNiece, Heldman.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Dr Hare reported having a patent for cardiac cell-based therapy, receiving research support from and being a board member of Biocardia, having equity interest in Vestion Inc, and being a consultant for Kardia. Dr George reported serving on the board of GE Healthcare, consulting for ICON Medical Imaging, and receiving trademark royalties for fluoroperfusion imaging. Mr Mendizabal is an employee of EMMES Corporation. Drs Rouy, Altman, and Wong Po Foo are employees of Biocardia Inc. Dr McNiece reported being a consultant and board member of Proteonomix Inc. Dr Heldman reported having a patent for cardiac cell-based therapy, receiving research support from and being a board member of Biocardia, and having equity interest in Vestion Inc. No other authors reported any financial disclosures.

Funding/Support: This study was funded by the US National Heart, Lung, and Blood Institute (NHLBI) as part of the Specialized Centers for Cell-Based Therapy U54 grant (U54HL081028-01). Dr Hare is also supported by National Institutes of Health (NIH) grants RO1 HL094849, P20 HL101443, RO1 HL084275, RO1 HL107110, RO1 HL110737, and UM1HL113460. The NHLBI provided oversight of the clinical trial through the independent Gene and Cell Therapy Data and Safety Monitoring Board (DSMB). Biocardia Inc provided the Helical Infusion Catheters for the conduct of POSEIDON.

Role of the Sponsors: The NHLBI, NIH, and Biocardia Inc had no role in the design and conduct of the study; in the collection, management, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.

Additional Contributions: We thank the NHLBI Gene and Cell Therapy DSMB, the patients who participated in this trial, the bone marrow donors, the staff of the cardiac catheterization laboratories at the University of Miami Hospital and The Johns Hopkins Hospital. Erica Anderson, MA (EMMES Corporation), provided data management and Hongwei Tang, MD (TeraRecon Inc), provided consultation regarding CT imaging analysis. Ms Anderson received compensation for her contribution via the Specialized Centers for Cell-Based Therapy grant. Dr Tang did not receive any compensation for his contribution.

This article was corrected for errors on July 19, 2013.

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JAMA | Comparison of Allogeneic vs Autologous Bone Marrow ...

Bone Marrow Stem Cells Comments Off on JAMA | Comparison of Allogeneic vs Autologous Bone Marrow … | October 9th, 2015

Scientists have discovered a new type of stem cell in the skin that acts surprisingly like certain stem cells found in embryos: both can generate fat, bone, cartilage, and even nerve cells. These newly-described dermal stem cells may one day prove useful for treating neurological disorders and persistent wounds, such as diabetic ulcers, says Freda Miller, an HHMI international research scholar.

Miller and her colleagues first saw the cells several years ago in both rodents and people, but only now confirmed that the cells are stem cells. Like other stem cells, these cell scan self-renew and, under the right conditions, they can grow into the cell types that constitute the skins dermal layer, which lies under the surface epidermal layer. We showed that these cells are, in fact, the real thing, says Miller, a professor at the University of Toronto and a senior scientist in the department of developmental biology at the Hospital for Sick Children in Toronto. The dermal stem cells also appear tohelp form the basis for hair growth.The new work was published December 4, 2009, in the journal Cell Stem Cells.

Stem cell researchers like to talk about building organs in a dish. You can imagine, if you have all the right playersdermal stem cells and epidermal stem cellsworking together, you could do that with skin in a very real way.

Freda D. Miller

Though this research focuses on the skin, Miller has spent her career searching for cures for neurological diseases such as Parkinsons. About a decade ago, she decided to find an easily accessible cell that could be coaxed into making nerves. Brain stem cells, some of which can grow into nerves, lie deep in the middle of the organ and are too difficult to reach if the scientists eventually wanted to cultivate the cells from individual patients. I thought, This is blue sky stuff, but you never know. She searched the literature and found that amphibians can regenerate nerves in their skin. She also found published hints that mammalian nerve cells could do the same.

Her team looked in the dermal layer of the skin in both mice and people. Hair follicles and sweat glands are rooted in the dermis, a thick layer of cells that also help support and nourish blood vessels and touch-perceiving nerves. In 2001, Millers team hit paydirt when they discovered cells that respond to the same growth factors that make brain stem cells differentiate. She named them skin-derived precursors (SKPs, or skips).

Miller soon discovered that the cells act like neural crest cells from embryosstem cells that generate the entire peripheral nervous system and part of the headin that they could turn into nerves, fat, bone, and cartilage.That gave us the idea that these were some kind of embryonic-like precursor cell that migrated into the skin of the embryo, Miller said. But instead of disappearing as the embryo develops, the cells survive into adulthood.

Even though the SKPs acted like stem cells in Petri dishes, Miller didnt know if they behaved the same way in the body. We were obviously very excited about these cells, she said. The problem was, cells can do all kinds of weird things in culture dishes that look right but really arent. We thought, Maybe were being deceived.So lab member Jeffrey Biernaskie put the cells through their paces, performing a series of experiments to test whether the SKPs indeed acted like stem cells in the body.

Earlier work in the lab had shown that the SKPs produce a transcription factor called SOX2, which is produced in many types of stem cells. The team used genetically engineered mice with SOX2 genes tagged with green fluorescent protein, which allowed them to track where SOX2 was expressed in the animals. They found that about 1% of skin cells from adult mice contained the SOX2-making cells, and they were concentrated in the bulb at the base of hair follicles.When the team cultured these cells, they began behaving like SKPs.

Next, the scientists decided to see if the cells would not just settle at the base of hair follicles but grow new hair. They took the fluorescent cells, mixed them with epidermal cellswhich make up the majority of cells in a hair follicleand transplanted the mixture under the skin of hairless mice. These mice began growing hair, and analysis showed the green cells migrated to their home base in the bulb of the new hair follicles. The team also transplanted rat SKP cells under the skin of mice. The cells behaved exactly like dermal stem cellsthey spread out through the dermis and differentiated into various dermal cell types, including fat cells and dermal fibroblasts, which form the structural framework of the dermal layer. Intriguingly, the mice that carried transplanted rat SKPs also grew longer, thicker,rat-like hair, instead of short, thin mouse hair. These cells are instructive, they tell the epidermal cellswhich form the bulk of the hair follicleto make bigger, rat-like hair follicles, Miller said. There are a lot of jokes in my lab about bald men running around with rat hair on their heads.

Finally, the team gave mice small puncture wounds and then transplanted their fluorescent SKPs next to the wound. Within a month, many transplanted cells appeared in the scar, showing they had contributed to wound healing. The SKPs were also found in new hair follicles in the healed skin.

The cells behavior both in wound healing and hair growth led the team to conclude that the SKPs are, in fact, dermal stem cells. Miller said the finding complements work by HHMI investigator Elaine Fuchs, who found epidermal stem cells, which help renew the top layer of skin. Combining the evidence from the two labs suggests a possible path to baldness treatments, Miller saidthe dermal stem cells at the base of the hair follicle seem to be signaling the epidermal cells that form the shaft of the follicle to grow hair. But much about the signaling mechanism remains unknown.

Miller wants to investigate less cosmetic applications, such as treating nerve and brain diseases. Experiments she published between 2005 and 2007 showed that SKPs can grow into nerves and help repair spinal cord damage in rats. Her lab is continuing to pursue that research. She is also searching for signals that could trigger the dermal stem cells to rev up their innate wound-healing ability. If such a signal can be found and mimicked, Miller can envision one day treating chronic woundssuch as diabetic ulcerswith a topical cream. Such a treatment is years or decades away, she said, but now researchers know which cell types to focus on. Another possibility: improving skin grafts, which today consist of only epidermal, not dermal, cells. While skin grafts can dramatically help burn victims, those grafts dont function like normal skin.

Stem cell researchers like to talk about building organs in a dish, said Miller. You can imagine, if you have all the right playersdermal stem cells and epidermal stem cellsworking together, you could do that with skin in a very real way.

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Research News: New Skin Stem Cells Surprisingly Similar to ...

Skin Stem Cells Comments Off on Research News: New Skin Stem Cells Surprisingly Similar to … | October 5th, 2015

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Our skin is an extremely important and multi-faceted organ. It protects our insides by providing a cover for our body and is responsible for preventing pathogens entering our organism. The skin also fulfills other important roles by regulating body temperature, in the area of metabolism, and for our sensitivity to touch and stimuli.

In addition, our skin also contains a large quantity of autologous stem cells (so-called adult stem cells). Autologous stem cells are on the one hand relevant for the external appearance of the skin, and on the other hand they offer a great deal of positive therapeutic potential in the area of regenerative medicine.

If we bear in mind what kind of functions our skin has, it becomes obvious why we should be paying special attention to its health.

Already in the traditional European medicine there was the tenet As inside, so outside. Even in modern science we know that it is important to distinguish between cause and effect and that many degenerative processes inside the body manifest externally.

For example, various factors can lead to a massive acceleration of the per se normal skin aging: Stress, overload and unhealthy diet can cause hormonal dysfunction, which in turn leads to premature aging and tissue slackening. Certain lifestyle habits such as tanning booths as well as smoking can cause skin damages over time, which can often make people concerned look more than 10 years older than they actually are.

Our therapeutic approach is not only to treat the symptom (= premature aging of the skin), but the cause (= e.g., hormone deficiency) as far as possible. Combinations of both the therapy of the cause and targeted local treatments can be useful, especially when a large distress is present and/or the skin damages are very advanced.

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Perfect Skin by DDr.Heinrich Beauty Drink

We use the autologous substances for our skin treatments. We never use artificial fillers (e.g., silicone) or Botox, because their side effects often lead to a worsening of skin quality.

When we are young, the body still has enough stem cells and produces sufficient growth factors and hormones, however, as the years pass, the body produces less of them. This wear process can be accelerated by stress, overwork, poor nutrition and certain lifestyle habits. The external signs of premature aging appear, such as wrinkles, slackening of tissue, sagging cheeks and greying of the skin.

All types of treatment offered by our clinic serve the purpose of giving your skin back a certain amount of quality, elasticity and freshness by targeted application of the autologous substances or substances similar to the bodys own.

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Skin Regeneration with Stem Cells, Growth Factors ...

Skin Stem Cells Comments Off on Skin Regeneration with Stem Cells, Growth Factors … | October 5th, 2015