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Click to view a previous story about Carly's battle.

October 30th brought a second challenge to Vinton-Shellsburg Kindergarten teacher, Carly Meyer. After battling her first round of leukemia, she suffered another relapse with a second diagnosis of leukemia.

"I thought I was done with these updates... but should have known 2020 wasnt done messing stuff up yet!" Carly shared. "For those of you who don't know, I was diagnosed with Acute Myeloid Leukemia in August 2019 and completed chemo treatments in December 2019, but unfortunately my lab results on October 30, showed some "blasts", which are the cancerous cells in my blood." She explained back in November that her lab results also showed that my WBC's the infection fighting cells, were very low.

At the beginning of November, she had another bone marrow biopsy which Wes, her husband believes is her 6th. She was then admitted to the University of Iowa Hospital for a month long stay.

Carly finished up her 5 days of chemotherapy on November 11th with only a couple of side effects (fatigue and loss of appetite) which are a couple of the more common side effects with chemotherapy treatments. Unfortunately, she suffered from dehydration as well and this caused her to pass out a couple of times, and one of the falls caused her to hit her head. This of course triggered a trip for a CT Scan just to make sure she was alright, fortunately, she didn't have any side effects from the fall.

"It is fairly common for leukemia patients to spike fevers and to get random bugs because we are neutropenic and our body cant fight off simple things they normally would," Carly explained. She did come down with an infection during this time but it was able to be pinpointed and treated right away. On Thanksgiving, she was able to return home 10 days earlier from her hospital stay than had been anticipated,

Her journey continues to beat cancer with a trip back to the hospital at the end of December, to begin preparation for her bone marrow transplant. "My hero of a brother started getting shots December 30 to prep and will be donating his Stem Cells on Monday, January 4th." Carly explained how the process works. Her brother Kyle was hooked up to a machine she said it is similar to donating blood/plasma and that the procedure lasts for about 5 hours. Fortunately, her brother Kyle was a 100% perfect match to be her donor.

The stem cells were then put into her IV Powerline over about 30 minutes while they closely monitored Carly for any side effects. "Then its just a waiting game after that," she said.

After the transplant, Carly's immune system was down to zero. Unfortunately, it is common for SCT patients to spike fevers and even get an infection after transplant.

New Year, New Me has never rang more true than this year Carly said.

She is hoping to be home at the end of the week. She said that this last stay has been "extremely exhausting mentally and physically." Developing mucositis, extreme sores and pain in her mouth, it has made it very hard to eat or drink anything. Mucositis is very common after receiving the strong chemo that she received just before her bone marrow transplant. She is slowly recovering from this.

She said that she is excited to be coming home with her husband and fur-baby Maverick if all goes well, by the end of the week.

"I am so lucky to have an amazing support system (especially my husband) to get me through this tough time," she said.

Please keep the couple in your prayers as Carly continues to heal.

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Cancer requires more tutoring, with Meyer continuing to Teaching Cancer a lesson - News - vintontoday.com

Bone Marrow Stem Cells Comments Off on Cancer requires more tutoring, with Meyer continuing to Teaching Cancer a lesson – News – vintontoday.com | January 22nd, 2021

Introduction

Bone remodelling is a tightly coupled lifelong process, whereby old bone is removed by osteoclasts (bone resorption) and new bone is formed by osteoblasts (bone formation).1,2 Osteocytes, which act as mechanosensors/endocrine cells, and bone lining cells3 are also involved in bone remodelling.4 Myriad pathophysiological factors affecting bone remodelling have been observed in skeletal diseases such as osteoporosis, arthritis and periodontal disease.5 Oxidative stress is one of the pathophysiological factors affecting bone remodelling. Oxidative stress stimulates osteoclast differentiation, thereby enhancing bone resorption.6,7 Reactive oxygen species (ROS) stimulate the apoptosis of osteoblasts and osteocytes, thus affecting bone formation. ROS also activate mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinases (ERK1/2), c-Jun-N terminal kinase (JNK) and p38, and enhance osteoclastogenesis and bone resorption.811 These phenomena skew the bone remodelling process in favour of bone loss.

Antioxidants are compounds which reduce free radicals and oxidative stress.12 Antioxidants have been reported to promote differentiation of osteoblasts, bone formation and survival of osteocytes, as well as suppressing osteoclast differentiation and activity.8,1315 Some studies associate the age-related reduction in circulating antioxidants to osteoporosis in rats and women.1618 A decline in antioxidant levels has been reported to promote bone loss by triggering the tumour necrosis factor-alpha (TNF)-dependent signalling pathway,6 while administration of antioxidants, such as vitamin C, E, N-acetylcysteine and lipoic acid, have been reported to exert favourable effects in animal models of osteoporosis1921 and individuals with osteoporosis.2225

Caffeic acid (CA) is a metabolite of hydroxycinnamate and phenylpropanoid commonly synthesized by all plant species. It is a polyphenol present in many food sources like coffee, tea, wine, blueberries, apples, cider, honey and propolis.26 CA and its major derivatives including caffeic acid phenethyl ester (CAPE) and caffeic acid 3,4-dihydroxy-phenethyl ester (CADPE) are reported to possess potential antibacterial, antidiabetic, antioxidant, anti-inflammatory, antineoplastic and cardioprotective activities (reviewed in2729). As a potent antioxidant, CA has been demonstrated to decrease lipoperoxyl radicals (ROO) by donating a hydrogen atom to its corresponding hydroperoxide, which terminates the lipid peroxidation chain reaction. It also inhibits human low-density lipoprotein (LDL) oxidation induced by cupric ions.30 Furthermore, it interacts with other compounds, such as -tocopherol, chlorogenic and caftaric acids, to exert more potent antioxidant activity in a variety of different systems.3133 Therefore, the antioxidant activities of CA might protect against the negative effects of oxidative stress on bone cells and the skeletal system. This systematic review aims to summarise the effects of CA and its derivatives on bone cells and bone in literature.

A systematic literature search was conducted from July until November 2020 using PubMed, Scopus, Cochrane Library and Web of Science databases to identify studies on the effects of caffeic acid on bone and bone cells including osteoblasts, osteoclasts and osteocytes. The search string used was (1) caffeic acid AND (2) (bone OR osteoporosis OR osteoblasts OR osteoclasts OR osteocytes).

Studies with the following characteristics were included: (1) original research article with the primary objective of determining the effects of caffeic acid on bone and bone cells; (2) studies using cellular or animal models, or humans; (3) studies administering caffeic acid as a single compound but not in a mixture or food. Articles were excluded if they (1) do not contain original data; (2) use food rich in caffeic acid or mixtures containing caffeic acid. The bibliography of relevant review articles was traced for potential articles missed during database search. The search results were organised using EndNoteTM software (Clarivate Analytics, Philadelphia, USA). Duplicates were identified using EndNoteTM and confirmed by manual checking.

Two authors (S.O.E. and K.L.P.) searched the same databases using the search string mentioned and screened the search results. All the articles that did not match the selection criteria were excluded. Next, the articles which used caffeic acid in treating models other than bone-related diseases were removed. Finally, articles which used caffeic acid in combination with other compounds were also excluded. Any disagreement on the inclusion or exclusion of articles was resolved through discussion among the two authors. The corresponding author (K.Y.C.) had the final decision on articles included if a consensus could not be reached between authors responsible for screening. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and checklist.34 Steps in the selection process, from identification, screening, eligibility to the inclusion of articles, are shown in Figure 1.

Figure 1 Flowchart of the article selection process.

From the literature search, 381 articles were identified, of which 87 were obtained from PubMed, 182 were from Scopus, 3 from Cochrane Library and 109 from Web of Science. A total of 155 duplicate articles were identified and removed. Of the 226 articles screened, 202 articles were excluded based on the selection criteria, whereby 51 articles did not contain primary data (3 book chapters, 2 commentary and 46 review articles), 147 articles and 2 conference abstracts presented topics irrelevant to the current review, a conference abstract had been published as a full-length research article and another conference abstract did not contain sufficient experiment details (Supplementary Material). Finally, 24 articles fulfilling all criteria mentioned were included in the review.

The included studies were published between 2006 and 2020. Seven studies were in vitro experiments using mouse bone marrow macrophages (BMMs), RAW264.7, RAW D and MG63 osteoblast cell lines3541 while 19 studies were in vivo studies using Sprague Dawley/Sprague Dawley albino rats, Wistar/Wistar albino rats, Balb/c mice, lipopolysaccharide (LPS)-resistant C3H/HEJ mice, C57BL/6J mice and ICR mice.35,38,4258 No human studies on this topic were reported.

Six in vitro studies focused on the effects of CA on osteoclast differentiation from haematopoietic cells using macrophage colony-stimulating factor (M-CSF), receptor activator of NF-B (RANK) ligand (RANKL) or TNF-,3539,41 while one in vitro study focused on the effect of CA on osteoblasts using MG63 osteoblast cell line.40 Four in vitro studies used CA doses between 0.15 M.35,37,38,40 Ang et al.36 used doses between 00.3 M and Sandra et al.41 and Sandra and Ketherin39 used a dose of 10 g/mL (55.5 M). The treatment period was 57 days for the differentiation of osteoclasts.

For animal studies, Duan et al.,55 Zawawi et al.,58 William et al.,51 Wu et al.,38 Zych et al.49 and Folwarczna et al.48,52 used CA or its derivatives at doses between 0.550 mg/kg via oral or intraperitoneal (i.p.) administration. Ucan et al.,57 Erdem et al.,53 Cicek et al.,54 Yigit et al.,45 Yildiz et al.50 and Tolba et al.56 used doses between 1020 mol/kg/day (2.845.69 mg/kg/day) via i.p. administration. Kizilda et al.4244 and Kazanciolu et al.46,47 used the dose of 10 mmol/kg/day (2.843 g/kg/day) for an i.p. administration, Kazanciolu et al.47 employed 50100 mmol/kg/day (14.2228.43 g/kg/day) for a localised administration, while Ha et al.35 used a collagen sponge soaked with CAPE with the final dose of 250 g/mouse. For oral administration, first-pass effect might affect the enteric absorption of CA or its derivatives.59 For i.p. administration, the injection is commonly performed at the lower left or right quadrant of the abdomen. The peritoneum can absorb the compounds fast and reach systemic circulation with greater bioavailability with fewer handling errors.60

The bone-related disease models used included ovariectomy (OVX)- or glucocorticoids (dexamethasone)-induced osteoporosis, polyethylene particle-induced bone defect and osteolysis, electromagnetic force (EMF)-stimulated bone loss, osteotomy- or anti-collagen antibody-induced arthritis (CAIA) and rapid maxillary expansion (RME) and LPS-induced periodontitis. The endpoints studied included bone microstructure, histomorphometry, bone remodelling and oxidative status. The effects of CA and its derivatives on bone remodelling have been summarized in Table 1.

Melguizo-Rodrguez et al. reported that 24-hour CA (1 M) incubation increased the number of MG63 osteoblast cells compared with control.40 Gene expression studies revealed that CA increased the expression of osteoblast-related genes such as bone morphogenetic protein-2 and -7 (BMP-2 and BMP-7), transforming growth factor-beta 1 (TGF-1), transforming growth factor-beta receptor 1, 2 and 3 (TGF-R1, TGF-R2 and TGF-R3) and osteoblastogenesis genes including Runt-related transcription (RUNX-2), alkaline phosphatase (ALP), collagen type 1 (COL-I), osterix (OSX) and osteocalcin (OSC).40 Additionally, pretreatment of CA (10 g/mL or 55.5 M) on RAW D cells for 2 h also significantly inhibited the RANKL and TNF-induced osteoclastogenesis with the suppression of p38 MAPK phosphorylation and tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells (OCLs) formation.39 Similarly, pretreatment of CA (0.1, 1 and 10 g/mL or 0.555, 5.55 and 55.5 M) on RAW D cells and BMMs for 3 days significantly inhibited the RANKL and TNF-induced osteoclastogenesis and NF-B activity in RAW-D cells and RANKL, TNF and M-CSF-induced osteoclastogenesis in BMMs.41

On the other hand, CAPE treatment (00.3 M; 57 days) suppressed the formation of TRAP-positive OCLs on RANKL-treated RAW264.7 cells and BMMs.36 Apoptosis occurred in CAPE-treated RAW264.7 cells with the disruption of the microtubule network in OCLs.36 Similarly, Kwon et al. reported that CAPE treatment (0.15 M) for 5 days suppressed OCLs formation from RANKL-stimulated RAW264.7 cells.37 Another study by Ha et al. treating M-CSF and RANKL-stimulated BMMs with CAPE (05 M for 57 days) also showed decreased OCLs formation in a concentration-dependent manner.35 The amount of TRAP-positive OCLs was decreased upon 0.1 and 0.5 M CAPE treatment by 30% and 95% respectively.35 No OCL formation was observed upon 1 M CAPE treatment.35 The anti-osteoclastogenic activities of CAPE are mainly contributed by its anti-inflammatory and antioxidant properties. Mechanistically, CAPE reduces superoxide anion generation by downregulating the nicotinamide adenine dinucleotide phosphate oxidase 1 (Nox1) expression through the interruption of nuclear factor-kappa B (NF-B) and c-Jun N-terminal kinase (JNK) signalling pathways.37 CAPE suppresses RANKL-mediated activation of the NF-B pathway by downregulating NF-B p65 subunit expression and its nuclear translocation,37 suppressing nuclear factor of activated T cells (NFAT) activities36 and degradation of NF-B inhibitor (IB),36,37 as well as inducing the degradation of IB kinase (IKK).37 CAPE also suppresses the expression and activation of JNK and its downstream transcription factors, such as c-Fos and c-Jun, which subsequently interrupt the protein activator-1 (AP-1) complex formation.37 Additionally, CAPE suppressed RANKL-induced activation of the Nox1 by inhibiting the Nox p47PHOX subunit translocation to the cell membrane and downregulation of Ras-related C3 botulinum toxin substrate 1 (Rac1) expression.37

On the other hand, Wu et al. reported that CADPE (0.15 M for 7 days) also concentration-dependently reduced OCL formation in the M-CSF and RANKL-stimulated BMMs and RAW264.7 cells.38 Mechanistic and characterisation examination revealed that CADPE suppressed RANKL-induced tumour necrosis factor receptor-associated factor 6 (TRAF6) activation and protein kinase B (PKB or also known as Akt) and activation of major MAPKs including ERK, JNK and p38.38 Subsequently, CADPE suppressed downstream expression of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), nuclear translocation of c-Fos protein and expression of osteoclastic markers, such as TRAP and cathepsin K, possibly through the non-receptor tyrosine kinase c-Src signalling.38 Interestingly, CADPE did not significantly affect the NF-kB signalling pathway and M-CSF-induced proliferation and differentiation of BMMs.

Supplementation of CA in animal models of bone loss yielded heterogeneous findings.48,49,52 This observation might be attributable to oral administration. Folwarczna et al. reported that CA (5 and 50 mg/kg, by stomach tube for 4 weeks) improved the bone mechanical properties by increasing the width of the trabecular metaphysis of the femur and decreasing the transverse growth in endosteal of the femur in OVX rats.48 Folwarczna et al. then demonstrated that CA (10 mg/kg/day; oral administration for 4 weeks) could reduce the width of tibial periosteal and endosteal osteoid compared with untreated OVX rats.52 However, CA did not promote or reduce the resorption of compact bone in the tibia of OVX-induced osteoporotic rats as evidenced by negligible changes of bone mass, bone mineral mass, bone mass/body mass ratio and bone mineral mass/body mass ratio.52 On the other hand, Zych et al. reported that CA at a similar dose (10 mg/kg/day; by stomach tube for 4 weeks) worsened the bone mechanical properties of healthy female Wistar Cmd:(WI)WU rats by decreasing the load of fracture at the femoral neck, decreasing the width of periosteal osteoid in the tibia and decreasing the width of the epiphysis and metaphysis trabecular in the femur compared with the negative control group.49

CAPE is the most extensively studied caffeic acid derivative in animal studies. The beneficial effects on new bone formation and healing upon systemic administration of CAPE had been reported.46,47,53,57 Erdem et al. reported that a low dose of CAPE (10 mol/kg; i.p. injection for 22 days) increased new bone formation and bone strength by increasing maximum torsional fracture momentum and degree of rigidity compared with negative control in rats that underwent unilateral femoral lengthening (osteotomy).53 Similarly, a 30-day i.p. injection of CAPE (10 mol/kg/day) also increased bone healing level in Sprague Dawley rats with cranial critical size bone defect.57 A higher dose of CAPE (10 mmol/kg/day, i.p. for 20 days) also further promoted the RME procedure-induced new bone formation in midpalatal suture of male Sprague Dawley rats.47 Similarly, a longer treatment period of CAPE (10 mmol/kg/day; i.p. injection for 28 days) also significantly promoted bone healing by increasing the total new bone areas in surgical-induced calvarial defects of male Wistar rats compared with the negative control.46 However, localised administration of CAPE (28 days) on surgical-induced calvarial defects by pre-mixing 50 and 100 mmol/kg CAPE solutions with gelatin sponges did not significantly improve the new bone formation.46

Localised and systemic administration of CAPE was reported to be beneficial in reducing osteolysis and bone loss.35,4245,50,5456,58 Ha et al. reported that collagen sponge implant impregnated with 250 g CAPE and RANKL could reduce osteoclastogenesis with significantly lesser TRAP-stained area in mouse calvariae compared with implants with RANKL only.35 Subcutaneous injection of CAPE (1 mg/kg/day for 10 days) reduced the polyethylene particle-induced calvarial osteolysis, surface bone resorption and TRAP-positive cells formation with an increase of bone volume (BV) on LPS-resistant C3H/HEJ female mice.58 However, no significant changes were observed in carboxy-terminal cross-linked type 1 collagen (CTX-1) and osteoclast-associated receptor levels among untreated and CAPE-treated rats with calvarial osteolysis.58

Similarly, Duan et al. reported that lower dose and frequency of CAPE injection (0.5 mg/kg twice a week; i.p. injection for 4 weeks) also increased the BV and trabecular number (Tb.N) due to the decrease of bone osteoclast formation (evidenced by decreased osteoclast number/bone perimeter) in OVX mice.55 Tolba et al. also reported that i.p. injection of CAPE (10 and 20 mol/kg) for 3 weeks increased femur weight and length in rats with dexamethasone-induced bone loss.56 The preservation of skeletal health in their study was associated with an improved antioxidant defence, such as higher levels of glutathione (GSH) and superoxide dismutase (SOD), and the reduction of malondialdehyde (MDA, lipid peroxidation product).56 This event led to an increase of osteoblastogenesis indicated by upregulation of RUNX-2 and ALP (osteoblast marker) levels56 On the other hand, decreased RANKL/osteoprotegerin (OPG) ratio was observed with CAPE treatment, indicating the suppression of osteoclastogenesis, which was further confirmed by lower acid phosphatase level and TRAP activity.56 In another study by Yildiz et al., CAPE (10 mol/kg/day; i.p. injection for 22 days) also increased the spine and femur BMD in rats with EMF-induced bone loss.50 Similarly, Cicek et al. reported a longer treatment of CAPE (10 mol/kg/day; i.p. injection for 28 days) also significantly improved the mechanical strength of cortical bone by increasing the breaking force, bending strength and total fracture energy in rats with EMF-induced bone loss compared with negative control.54

Additionally, a study by Wu et al. treated mice with an OVX-induced bone loss with a moderately high dose of CADPE (10 mg/kg; i.p. injection) every 2 days for 3 months.38 Results showed that CADPE could increase the BV fraction (BV/TV) and Tb.N, as well as decreased trabecular spacing (Tb.Sp) compared with the negative control.38 The improvement in the bone structure was contributed by reduced osteoclast number and eroded surface on the bone.38 Assessment of bone remodelling markers also revealed that serum TRAP5b and CTX-1 levels were reduced in CADPE-treated group compared with the negative control.38

On the other hand, CAPE was effective in reducing periodontitis-related bone loss and osteolysis.4245 CAPE (10 mol/kg/day, i.p. for 14 days) significantly reduced the subgingival ligature placement-induced periodontitis-mediated articular bone loss, histopathological features and severity of periodontal inflammation with lesser polymorphonuclear cells (PMNLs) infiltration in the junctional epithelium and connective tissues among Wistar albino rats.45 CAPE also suppressed the periodontitis-upregulated interleukin (IL)-1, IL-6, IL-10, TNF, MDA levels and the percentage of gingival apoptosis with the parallel restoration of periodontitis-downregulated GSH and glutathione peroxidase (GPx).45 Administration of high-dose CAPE (10 mmol/kg/day; i.p. for 15 days) in streptozotocin (STZ)-induced diabetic male Sprague Dawley rats reduced RANKL-positive osteoclast number, IL-1 levels, oxidative stress index (OSI), alveolar bone loss and histological analysis score in LPS-induced periodontitis. The treated rats also suffered lesser inflammatory reactions, ulcers and hyperemia.42 Similar changes of osteoclast number, IL-1 and OSI were observed in male Sprague Dawley rats with chronic stress and LPS-induced periodontitis treated with CAPE (10 mmol/kg/day, i.p. for 14 days).44 In addition, CAPE also increased the mesial and distal periodontal bone supports (MPBS and DPBS) in these rats.44 The effects of CAPE were sustained with a longer treatment period of CAPE (10 mmol/kg/day, i.p. for 28 days) on male Sprague Dawley rats with LPS-induced periodontitis.43

In contrast to the above findings, Williams et al. reported that subcutaneous injection of CAPE (1 mg/kg; at day 3, 7 and 10) did not reduce paw inflammation or bone loss in CAIA mice.51 Cartilage and bone degradation, as well as TRAP-positive cells on the bone surface and soft tissues, were still apparent in the supplemented CAIA group compared with the normal control.51

This systematic review found that although CA and its derivatives is a potential anti-osteoporosis agent by suppressing the formation of osteoclasts and their bone resorption activity, it worsened bone mechanical properties in some cases. The anti-osteoclastogenesis action of CA and its derivatives was mediated by the antioxidant activities, which blocked RANKL-induced TRAF6/Akt and MAPK signalling, as well as M-CSF/c-Src signalling. In animals, CA and its derivatives (mainly CAPE) prevented bone resorption in rodent calvariae when implanted in situ, facilitated the healing of bone defects, preserved bone structure and improved mechanical strength in osteoporosis models induced by OVX, dexamethasone, osteotomy, LPS-mediated periodontitis and EMF. However, CA did not alter bone resorption in OVX-induced osteoporotic rats and worsened the mechanical properties in normal rats. Additionally, CAPE did not suppress bone loss in rats with CAIA-induced bone loss.

Osteoblasts are bone-forming cells derived from bone marrow mesenchymal stem cells and are responsible for the synthesis, secretion and mineralisation of bone matrix.61 The expression of osteoblast markers was increased following CA or CAPE supplementation, an indication that CA and CAPE stimulated osteoblast proliferation, differentiation and maturation.40,56 Osteoblasts and osteocytes regulate the formation of osteoclasts through RANKL/OPG axis. Osteoblasts and osteocytes synthesise RANKL, which binds to RANK to activate the canonical pathway for osteoclastogenesis. They also secrete OPG, which is a decoy receptor for RANKL to suppress osteoclastogenesis. The production of RANKL is stimulated under conditions such as oestrogen deficiency62 and oxidative stress.63 Osteoclastogenesis can also be stimulated via a non-canonical pathway, for instance, through the binding of TNF with TNF receptor I or II.64 Glucocorticoids are potential modulators of RANKL/OPG axis, whereby dexamethasone is shown to downregulate OPG levels in osteoblasts.65 Tolba et al. showed that the RANKL/OPG level reduced in rats induced with dexamethasone with CAPE treatment.56 Other cellular studies showed that CA and its derivatives suppressed RANKL- and TNF-induced formation of OCLs from haematopoietic cells,3539 indicating that CA and its derivatives suppressed both canonical and non-canonical osteoclastogenesis.

The complex formed by the binding of RANKL to RANK causes the recruitment of the adaptor molecules tumour necrosis factor receptor-associated factors (TRAFs), including TRAF6.66 This event leads to the activation of several downstream signalling pathways, including c-Src/Akt/phosphatidylinositol 3-kinase and MAPKs (ERK/p38/JNK). CADPE was shown to suppress RANKL-induced activation of TRAF6 activation and the subsequent signalling pathways in multiple osteoclast progenitors, such as BMMs,38 RAW264.738 and RAW D cells.39 Sandra and Ketherin suggested that the downregulation of p38 is the key step of CA-mediated osteoclastogenesis.39 Upon activation, p38 initiates osteoclastogenesis by inducing NF-B and NFATc1 expression.67,68 Inhibition of p38 MAPK reduces RANKL (canonical) and TNF-induced (non-canonical) osteoclast formation.69

The NF-B pathway is another signalling pathway downstream of TRAFs critical for osteoclast differentiation and bone reabsorption activity. Upon activation, IKK (consisting of IKK, IKK and IKK) phosphorylates and degrades IB, which enables translocation of NF-B p65/p50 heterodimers into the nucleus to allow transcription of osteoclast-related genes.70 Kwon et al. demonstrated that the anti-osteoclastogenesis effects of CAPE were mediated via the degradation of total IKK, thereby preventing the phosphorylation and degradation of IB and subsequently suppresses the nuclear translation of p65.37 On the other hand, Wu et al. reported that CADPE did not affect phosphorylation or degradation of IB, as well as nuclear translocation, and DNA-binding activity of p65.38 This observation suggests that compared with CAPE, CADPE does not influence the NF-B signalling pathway.

ROS are one of the important secondary signals in the early stages of osteoclast differentiation.71,72 These ROS are mainly produced as superoxide anions by Nox1.73 Blocking of Nox1 ameliorates ROS production and the downstream MAPKs (JNK, p38 and ERK) and NF-B activation74 and subsequently suppresses the osteoclast formation.71 The reduction of Nox 1 and Rac1 expression by CAPE is accompanied by RANKL-downstream signalling, denoting that anti-osteoclastogenesis effects of CAPE are dependent on suppression of Nox1-mediated superoxide anion production. Besides, dexamethasone has been reported to increase the expression of oxidative stress-related genes in human osteoblasts.75 Tolba et al. showed that CAPE increased GSH and SOD but reduced MDA in the bone of the rats exposed to dexamethasone, indicating an improvement of redox status in the skeletal environment.56 Additionally, CAPE also reduced the OSI and bone loss with an improvement of bone support in rats with LPS-induced periodontitis.

NFATc1 is the master regulator of osteoclast-related gene expression, and it is activated by c-Fos and NF-B.76 Ha et al. observed that CAPE inhibited the recruitment of NF-B to NFATc1 promoter, and the combined effect of NF-B inhibition on c-Fos and NFATc1 may have caused CAPE to suppress osteoclastogenesis effectively.35 Holland et al. demonstrated a new fluorinated derivative of CAPE possesses potent anti-osteoclastogenic properties on RAW 264.7 cells by downregulating NFATc1 via suppression of c-Fos and NF-B signalling pathways.77 Besides, this new fluorinated CAPE also exhibits improved stability with a 2-fold higher potency than CAPE.77 On the other hand, although CADPE did not alter NF-B signalling, it still could suppress NFATc1 and other osteoclast-related markers, indicating other mechanisms of suppression could be involved, for instance, c-Src and MAPKs signalling pathways.38

Matrix metalloproteinases (MMPs), including gelatinases (MMP-2 and MMP-9) are examples of zinc-dependent extracellular matrix-degrading enzymes, which actively participate in bone resorption.78 MMPs are expressed as inactive proenzymes or zymogens that can be activated by several mediators including AP-1, NF-B, TNF and TGF.78 Currently, there is no study conducted to investigate the inhibitory effects of CA and CAPE on osteoclastic MMPs activity and its subsequent linkage in bone resorption; interestingly, CA and CAPE were reported to inhibit MMP-9 activity in human hepatocellular carcinoma HEP3B cells.79,80 This observation renders an interesting research gap in osteoclastic MMP inhibition upon CA and its derivatives treatment.

Suppression of osteoclastogenesis by CA or its derivatives have significant therapeutic potential against bone disorders induced by excessive bone resorption. Bone loss after osteotomy is a rapid process that affects both fractured and unfractured bone and may be incompletely reversible.81 CAPE was reported to improve bone formation and mechanical strength of bone in osteotomy.53 Exposure to EMF radiation caused by high-voltage transmission lines and transformers could affect bone health through decreased BMD, serum calcium and ALP level leading to the increase of bone resorption.82 CAPE increased the spine and femur BMD levels50 and increased mechanical strength of bones54 in rats exposed to EMF radiation. Total hip arthroplasty without cement often caused osteolysis induced by polyethylene particles.83 CAPE was shown by Zawawi et al. to prevent calvarial bone resorption in a murine polyethylene particle-induced osteolysis model.58 Therefore, biomaterials impregnated with CA or its derivatives could be adopted to prevent osteolysis in the arthroplasty procedure. CA has been incorporated in chitosan/(3-chloropropyl) trimethoxysilane scaffold for hard-tissue engineering applications and this adopted material exhibits antibacterial and anticancer effects.84 Ucan et al. observed that CAPE increased cranial bone healing in rats with critical size bone defect, suggesting that it could be administered systematically or locally to treat bone fracture/defect healing.57

Similarly, CAPE also effectively reduced the articular bone loss, inflammatory cytokines production and oxidative stress in rats with LPS-mediated periodontitis. Additionally, Wu et al.38 and Duan et al.55 demonstrated that CADPE prevented the ovariectomy-induced bone loss by suppressing osteoclast activity in a mouse model, while Folwarczna et al. showed increased width of trabecular metaphysis in the femur of OVX rats.48 Similarly, Tolba et al. showed improved bone formation and skeletal health in rats with dexamethasone-induced bone loss upon receiving CAPE.56 Additionally, CA and its derivatives may be involved in oestrogen production and signalling. Zych et al. reported that an oral administration of CA (10 mg/kg/day for 4 weeks) significantly restored the serum oestradiol levels in OVX rats.85 Interestingly, CA at 10 and 100 M did not cause any alteration in calcium content in the femoral-diaphyseal and metaphyseal ex vivo culture, suggesting its bone-protecting effect may not involve calcium metabolism and regulation.86 Additionally, CAPE was reported as a selective human oestrogen receptor agonist with the EC50 value of 3.72 M in oestrogen-responsive element transcription.87 A recent in silico study by Zhao et al. suggested potential osteoimmunological effects of CAPE, which may explain its biological activities on both immune and skeletal systems.88 However, the findings from this modelling study requires further validation through in vitro and in vivo models. As oestrogen deficiency due to menopause and glucocorticoids present the most significant cause of primary and secondary osteoporosis globally, CA and its derivatives have the potential to be used as an adjuvant therapy to existing osteoporosis management strategies. The mechanisms of action of CA and its derivatives in osteoclastogenesis have been summarized in Figure 2.

Figure 2 Mechanism of action of caffeic acid and its derivatives.

Abbreviations: , decrease or downregulate; ?, unknown mechanism; Akt, protein kinase B; AP-1, activator protein 1; CA, caffeic acid; CADPE; caffeic acid 3,4-dihydroxy-phenethyl ester; CAPE, caffeic acid phenethyl ester; c-Src, cellular sarcoma tyrosine kinase; ERK1/2, extracellular signal-regulated kinases 1/2; GM-CSF, granulocyte-macrophage colony-stimulating factor; Grb2, growth factor receptor-bound protein 2; IFN-, interferon-gamma; IL, interleukin; IL1R, interleukin-1 receptor; IB, NF-B inhibitor protein; IKK, IB kinase; LPS, lipopolysaccharide; M-CSF, macrophage colony-stimulating factor; M-CSF-R, M-CSF receptor; MAPKs, mitogen-activated protein kinases; NFAT, nuclear factor of activated T cells; NF-B, nuclear factor kappa B; NIK, MAPK kinase kinase 14; Nox1, nicotinamide adenine dinucleotide phosphate oxidase 1; OPG, osteoprotegerin; PI3k, phosphoinositide 3-kinase; Rac1, Ras-related C3 botulinum toxin substrate 1; RANK, receptor activator of NF-B; RANKL, receptor activator of NF-B ligand; ROS, reactive oxygen species; TAK, MAPK kinase kinase 7; TLR4, Toll-like receptor 4; TNF, tumour necrosis factor-alpha; TNFR1/2, TNF receptor 1/2; TRAF2, tumour necrosis factor receptor-associated factor 2; TRAF6; tumour necrosis factor receptor-associated factor 6.

Regardless of the positive effects of CA on bone status, some studies have reported negative effects associated with supplementation of CA and its derivatives. CA supplementation did not affect the bone resorption52 and reduced transverse growth of endosteal in femur48 of rats with OVX-induced osteoporosis. In normal rats, CA supplementation even negatively affected their bone mechanical properties.49 Moreover, CAPE supplementation has been reported to stimulate the synthesis of PGE2,89 which mediates osteoclastogenesis through RANKL stimulation and activation of the NF-B pathway.90 This event will eventually increase TRAP-positive OCLs. Similarly, Williams et al. showed that CAPE did not suppress osteoclastogenesis in rats with CAIA.51

In term of safety, the International Agency for Cancer Research classifies CA as Class 2B (possibly carcinogenic to humans),91 and it was reported to induce renal tubular cell hyperplasia, forestomach hyperplasia, renal cell adenoma and forestomach cancer in rodents.9294 CA has been reported to be non-mutagenic and non-clastogenic.91 Therefore, its carcinogenicity may involve epigenetic modification. Human toxicity and carcinogenicity of CA and its derivatives remain unknown. CA also showed anti-implantation activity in pregnant mice at a median effective dose of 4.26 mg/kg/day.95 Similarly, 5 mg/kg/day and 150 mg/kg of CA in mice demonstrated anti-implantation activity in early pregnancy.96 On the other hand, 0.15 mg/kg/day, 5 mg/kg/day and 150 mg/kg/day of CA for 21 days in mice showed no maternal toxicity, foetal teratogenesis or post-natal effects on pup development and mortality.96 The same experiment stated that the no-observed-adverse-effect level of CA for pregnant female mice was 0.15 mg/kg/day.96 Therefore, high-dose CA should be cautioned in humans, especially pregnant women.

Several common limitations can be identified from the studies reviewed. Most studies did not adopt a positive control to compare against the anti-osteoclastogenesis or anti-osteoporosis effect of CA. Therefore, the therapeutic effects of CA and currently available anti-resorptive therapy cannot be compared. Although osteoblastogenesis and bone formation are also important in bone remodelling, evidence of CA on these processes is limited in the literature. The actions of CA in humans cannot be confirmed due to the lack of human clinical trials. These aspects can be improved in future studies.

The current review also has several limitations. We only considered articles indexed by PubMed, Scopus, Cochrane Library and Web of Science; therefore, non-indexed articles could be overlooked. We only selected articles studying CA or its derivatives as a single compound to understand its mechanism of action properly without other interference, but not a mixture of compounds or natural products rich in CA. CA are present in foods, and interaction with other compounds in the food matrix might alter its absorption, bioavailability and action on the target tissue. Moreover, the heterogeneous findings of CA in bone loss reduction upon oral administration further emphasise these possibilities.

The current preclinical evidence agrees that CA and its derivatives exert promising skeletal protective effects by inhibiting osteoclastogenesis and bone resorption, but literature on bone formation is limited. Notwithstanding that, the skeletal effects of CA and its derivatives in models of normal bone health should be investigated because the limited studies available show undesirable effects. Human clinical trials to validate the skeletal effects of CA are lacking. Therefore, a well-planned clinical trial should be conducted to confirm the potential of CA as an antiresorptive agent. This information is critical for CA and its derivatives to be incorporated as part of the strategies to prevent bone loss.

The researchers are funded by Universiti Kebangsaan Malaysia through Research University Grant (GUP-2020-021). S.O.E. and K.L.P. are post-doctoral researchers funded by Universiti Kebangsaan Malaysia through FPR-1 and RGA-1 grants.

The authors report no conflicts of interest in this work.

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[Full text] Effects of Caffeic Acid and Its Derivatives on Bone: A Systematic Revi | DDDT - Dove Medical Press

Bone Marrow Stem Cells Comments Off on [Full text] Effects of Caffeic Acid and Its Derivatives on Bone: A Systematic Revi | DDDT – Dove Medical Press | January 22nd, 2021

Introduction

Recent literature reviews suggest that bisphosphonates (BPs) may contribute to the growing number of cases of osteonecrosis involving the maxilla and mandible that are associated with the pathogenesis of BP-related osteonecrosis of the jaw (BRONJ).1 In the discussion concerning BRONJ, a distinction must be made between diseases featuring reduced osseous mineral content, which may be counteracted by BPs (such as those occurring during menopause or in cases of osteoporosis), and cases that present with indications for BPs (such as tumors). BPs have been used in the treatment of multiple myeloma, breast cancer, prostate cancer, and other tumors. In patients with metastatic breast cancer, the bones are affected in around two-thirds of cases. To protect patients from bone fractures and to reduce pain, patients are often prescribed BPs or a special antibody that prevents the breakdown of, and subsequently stabilizes, affected bone. BRONJ is a newly emerging problem that is recognized as a serious complication of BP therapy, primarily following intravenous (IV) administration.2

The concern is that BPs affect the natural remodeling of bone tissues and delay the breakdown of older bone structures. BPs are potent inhibitors of bone resorption and have a chronic effect over a half-life of at least 5 years, possibly exerting their effects for more than 10 years. BRONJ is a seemingly growing epidemic associated with osteonecrosis of the jawbone (ONJ).35 The long-term effects of oncological-related BP treatment on alveolar bone quality include the impact on BP-induced overexpression of alveolar bone remodeling. There are increased osteosclerotic properties in the alveolar bone that are associated with significantly greater bone volume and higher bone density.6,7 The risk of BP therapy is divided into two categories: local and systemic risk factors; thus, a distinction must be made between oral and IV administration. Local oral risk factors for BRONJ in cancer patients include dentoalveolar surgery, dental extraction, and dental implant insertion.8 Periodontal infections also significantly increase the risk of BRONJ in cancer patients.9 In addition, there is a significant correlation between the use of removable prostheses, the administration of high-dose IV BPs, and an increased risk of BRONJ.10 In patients receiving oral BP therapy for the treatment of osteoporosis, the prevalence of BRONJ only increased 0.21% from close to 0%. Systemically, however, there is a much higher risk associated with the IV injection of BPs. This is closely related to the frequent use of BPs in cancer patients who receive a significantly higher total dose over a longer duration.11 The mean and minimum time for the development of ONJ is 1.8 years and 10 months, respectively.12 The risk of BRONJ in cancer patients exposed to BP therapy is from 50100 times higher than in cancer patients treated with a placebo. The BRONJ risk for the RANKL inhibitor denosumab was between 0.7% and 1.9%.13,14 The risk of ONJ in cancer patients treated with high doses of IV BPs appears to be significantly higher: in the range of 110 per 100 patients (depending on therapy duration).15 A recent review reported a wide-ranging BRONJ incidence of 027.5% that was associated with the IV administration of BPs, with an average incidence of 7%.16 The cumulative frequency varied from 0.812.0% and was estimated to be up to 30.0% in some reports.17,18 Despite numerous publications on the subject, the overall pathogenesis of BRONJ does not yet appear to be fully understood. In particular, the reasons why only a subset of patients (<30%) receiving IV BPs develop BRONJ remain unclear. Although most patients that develop BRONJ have a history of tooth extraction or injury, these factors do not fully explain the occurrence of BRONJ.8 The development of BRONJ in edentulous areas in patients with no apparent history of injury suggests that pre-existing conditions, such as subclinical infections or potentially necrotic areas of the jawbone, may contribute to the conditions that lead to the development of BRONJ.

Why does BRONJ develop in up to 30% of individuals following IV BP therapy and not the remaining 70%? This review raises the question of whether little-known or difficult-to-identify, pre-existing, impaired bone remodeling, such as that occurring in aseptic-ischemic osteonecrosis of the jaw (AIOJ), bone marrow defects (BMD), or fatty-degenerative osteonecrosis of the jawbone (FDOJ), represents a local risk factor in the development of BRONJ.

There is still a limited scientific understanding of the relationship between ONJ and BPs.19 In order to clarify the research question and present the background and specific common characteristics of AIOJ/BMD/FDOJ and BRONJ, an extensive literature search was carried out in PubMed Central. In the literature, the terms aseptic-ischemic osteonecrosis of the jaw (AIOJ), bone marrow defects (BMD), and fatty-degenerative osteonecrosis of the jawbone (FDOJ) are used to describe an intramedullary phenomenon with the same pathogenesis, morphology, and pathohistology.

The American Association of Oral and Maxillofacial Surgeons published four staging criteria (at risk, Stage 03).20 Stage 0 is of particular interest in our research as it refers to patients with no clinical evidence of exposed bone, but presence of non-specific symptoms or clinical and/or radiographic abnormalities. The discussion concerning BRONJ is complicated by the fact that there are two clinical forms of BRONJ. The first presents as exposed bone in the maxillofacial region with clinically recognizable necrotic bone that is visibly exposed through the oral mucosa or facial skin, and present for more than 8 weeks, which is referred to as so-called exposed BRONJ.15 The second form of BRONJ is particularly interesting for our investigation; it was recently emphasized that BRONJ does not always appear with necrotic bone visible through a breech in the oral mucosa.21 This form is referred to as non-exposed BRONJ (NE-BRONJ). In the absence of exposed bone, it is characterized by clinical features associated with the jaw, such as unexplained jawbone pain, fistulas/sinus tracts, loose teeth, and swelling.22,23 Diagnosing NE-BRONJ is difficult, as other common jawbone diseases, such as odontogenic infections, may cause similar symptoms and must be excluded. The non-exposed variant may comprise up to one third of all BRONJ cases and is thus not uncommon;24 however, this previously underestimated NE-BRONJ is difficult to accurately diagnose. Recently published papers emphasize that NE-BRONJ has received little attention so far and does not fulfill the current definition of BRONJ.25 Nevertheless, NE-BRONJ belongs to the same disease as exposed BRONJ and should be identified as part of the full spectrum of BRONJ (see the section titled, Case descriptions of AIOJ/BMD/FDOJ, non-exposed BRONJ, and Actinomyces colonization).26

Our investigation requires the identification of the basic immune mechanisms associated with BP administration. Specifically, which mechanism is behind the anti-tumor activity of BPs in cancer patients?

Various studies postulate that BPs change the bone microenvironment around cancer cells, which may prevent cancer cell survival and disease recurrence.27 BPs may also reduce the appearance of disseminated tumor cells. The formation of metastases is complex; mesenchymal stem cells (MSCs) are predominantly found in the bone marrow.28 MSCs may contribute to the formation of metastases through various mechanisms: (1) MSCs are recruited to develop breast tumors where they can enhance the metastatic potential of weakly tumorigenic breast cancer cells;29 (2) MSCs and other bone marrow cells may form a pre-metastatic niche within the specific tissues to which tumor cells metastasize;30 and (3) MSCs are able to maintain the growth and survival of cancer cells in the bone microenvironment where they may contribute to the formation of niches for dormant micrometastases that can later form distant metastases. BPs significantly reduce the ability of MSCs to migrate, thereby reducing the growth and survival of cancer cells.31 Thus, the effects of BPs on MSCs in the bone marrow microenvironment contribute to anti-tumor activity by affecting the ability of MSCs to migrate and develop tumors in pre-metastatic niches. BPs disrupt the interaction between MSCs and breast cancer cells within the bone microenvironment, where BPs may also directly inhibit breast cancer cell growth.

The antiangiogenic effect of BP administration in tumor patients also plays a role in therapy.32 When administered systemically, BPs effectively inhibit angiogenesis. The pronounced antiangiogenic properties of BPs enhance their effectiveness in the treatment of malignant bone diseases. In addition to suppressing RANTES/CCL5 (R/C) expression in MSCs, BP administration plays a role in the treatment of tumor patients.33 Similar to exogenous glucocorticoids and estrogen,34 BPs are ischemic and hypoxia-related stressors of bone health that alter jawbone metabolism, thus leading to osteonecrosis. While tumor-associated BP therapy is currently the heavy weight for bone health, it may accelerate existing, chronic pathophysiological events within the microcirculation of bone marrow compartments in the jaw. BRONJ development is often characterized by a slow start and usually presents with infarcts and thrombosis of small vascular sections of the supplying artery within the medullary canal; these features also correspond to AIOJ/BMD/FDOJ. Myeloid elements (including fat marrow) liquefy and cancellous trabeculae are resorbed, so that individual bone spaces merge and gradually create larger cavities.

If we compare the findings in the sections titled, Bisphosphonates and mesenchymal stem cells and Bisphosphonates and antiangiogenesis to pre-existing AIOJ/BMD/FDOJ, several strikingly common characteristics shared by BRONJ and AIOJ/BMD/FDOJ can be observed that help to answer our research question. In the sections following Bisphosphonates and antitumor therapy, we present the foundations for the development of AIOJ/BMD/FDOJ and draw similarities with the development of BRONJ.

The key function of proinflammatory chemokines R/C in the formation of breast cancer and its metastasis, as well as a possible connection with the intramedullary signaling of R/C overexpression from AIOJ/BMD/FDOJ areas, has been pointed out in previous studies.35,36 The conspicuous overexpression of R/C in little-known BMDs, as found in AIOJ/BMD/FDOJ, has been reported.37,38 R/C overexpression is a regulator of healthy bone metabolism in bone needing repair. The starting point for a typical AIOJ/BMD/FDOJ BMDs is the expression of R/C and its chemokine receptors (CCR5) in both osteoblasts (OBs) and osteoclasts (OCs). Ligands (CCL5) and receptors (CCR5) simultaneously activate autocrine and paracrine mechanisms in the bone.39 One study examined the effects of BPs on human primary OBs and was able to show that the overexpression of proinflammatory R/C from BP-treated OBs also occurs in areas affected by BRONJ.40 The secretion of proinflammatory cytokines interleukin (IL)-8 and R/C increased after 14 days of treatment with the highest dose of BPs.40 The complexity of cytokine control becomes clear at this point. In contrast to the tumor, where BPs in the MSCs reduce R/C expression to such an extent that metastasis is prevented, R/C expression is increased by BPs in OBs. If AIOJ/BMD/FDOJ is already present, it may be assumed that the associated increased R/C secretion is thus further increased by BPs. Specifically, NE-BRONJ may develop as BPs increase the expression of IL-8 and R/C.41 Other researchers have confirmed increases in the secretion of proinflammatory IL-8 and R/C from BP-treated OBs.42 Combined with the lower proliferation rate of OBs and a decrease in their differentiation, higher doses or accumulations of BPs cause undesirable local changes in the bone by increasing the secretion of IL-8 and R/C from OBs. If these findings are applied to BP administration in the context of a chronic, pre-existing AIOJ/BMD/FDOJ area, then such areas may be expected to exhibit increased R/C secretion in response to BPs. This increase may result from the inhibition of OC activity, leading to the development of BRONJ. Figure 1 summarizes the effects of BP administration on the pre-existing physiological derailments associated with tumor and osteoporosis development.

Figure 1 Comparison of the effects of BP administration (+BP) in the context of a tumor (upper part of Figure 1) and pre-existing osteoporosis (lower part of Figure 1). Legend: The red arrows indicate overactivity; the green arrows show reversal following BP administration.

In the literature, the vascular composition of AIOJ/BMD/FDOJ is characterized by the fact that blood flow in the medullary canal is impaired by micro-infarcts, which leads to chronic marrow ischemia.43 BRONJ also shows reduced vascularization in the medullary canal.44 Several publications have shown that ischemic bone diseases such as AIOJ/BMD/FDOJ and BRONJ are of multifactorial origin and emphasize the multiple stroke model as the cause of ischemic bone diseases.45,46 In the orthopedic literature, intensive research conducted on the development of ischemic bone disease in the early stages of the disease process is presented.47 Our aim here is to apply this knowledge not only to extreme forms of the disease, such as osteoradionecrosis and BRONJ, but also to chronic, subclinical, and ischemic forms such as bone marrow edema and AIOJ/BMD/FDOJ, which often progress asymptomatically. Many of these forms are manifestations of both local and systemic risk factors that compromise circulation in the bone marrow, and may also impact on the homeostasis of bone resorption and formation, in addition to BP therapy. The importance of this multifactorial exposure to risk factors for ischemia and the associated causal genetics that are very similar to those in cases of AIOJ/BMD/FDOJ is shown by observing how bone that is exposed to BPs demonstrates minimal OC activity, followed by the deposition of newly formed, thicker bone with reduced vascular supply.48 The resulting mosaic-like pattern of bone remodeling is strikingly similar to that found in Pagets disease, which tends to be associated with the development of osteomyelitis.49 Similar to AIOJ/BMD/FDOJ, the remodeling induced by BPs leaves cavities, otherwise known as cavitations, which leads to both necrosis and unlike that which is found in AIOJ/BMD/FDOJ subsequent infection by colonizing bacteria. Many patients with AIOJ/BMD/FDOJ have inherited prothrombotic tendencies, which is comparable to what is found in patients with idiopathic osteonecrosis of the femoral head (Pagets disease) and includes thrombophilia and hypofibrinolysis.5052 Although a consensus has been reached that ischemic marrow edema is not part of the pathogenesis of BRONJ,53 it is regarded as a typical characteristic of AIOJ/BMD/FDOJ, serving as a precursor to BRONJ development. Systemic antibiotic therapy has limited access to these avascular zones and surgical debridement is usually necessary.

The initial OB situation found in AIOJ/BMD/FDOJ is highly characteristic; under pathological conditions, OBs express R/C chemokines in a non-physiological manner.54,55 The increasing frequency of ONJ and its possible association with high cumulative doses of BPs was investigated in one study, which concluded that high doses of BPs had both OC and OB effects, and thus bone remodeling was inhibited in vivo.56 Other researchers have examined the proliferation, viability, expression, and secretion of bone markers and cytokines/chemokines from primary OBs following exposure to BPs.42 Increased concentrations of proinflammatory cytokines were found in response to BPs. Similarly, increased R/C expression is present in AIOJ/BMD/FDOJ. Following treatment with the highest dose of BPs, the secretions of proinflammatory cytokines IL-8 (P<0.001) and R/C (P<0.001) were significantly increased after 14 days. In addition, the secretion of proinflammatory R/C from OBs exposed to BPs increased. It has also been determined that R/C plays a role in the etiology of the osteolytic changes that are present in AIOJ/BMD/FDOJ.37,57 The aim of another study was to investigate the effect of BPs on human OBs in vitro, while considering RANKL and osteoprotegerin (OPG), both of which mediate OC differentiation.40 OPG increased significantly in the group that received BPs at a dose of 10 M, while RANKL expression decreased significantly with different concentrations of BPs. In summary, exposure to various BP concentrations had a positive effect on OB differentiation, but did not affect proliferation. In contrast, the BP-associated changes in RANKL and OPG production contributed to the suppression of osteoclastic bone resorption. Excess R/C leads to OC inhibition which, in our model, also leads to a disturbance in RANK/RANKL homeostasis (see Figure 2). The chain of reactions that arise from pre-existing AIOJ/BMD/FDOJ and BP administration result in the development of BRONJ in response to the subsequent OB depression; it also leads to increased OC apoptosis. In addition, bone densification takes place following BP administration as a result of increased OB activity. As such, osteonecrosis occurs in the jawbone when BPs are used parenterally. The reasons for these different reactions to BPs have not yet been clarified.

Figure 2 The effects of BP administration and the characteristics of AIOJ/BMD/FDOJ both include depressed alkaline phosphatase (AP) activity with subsequent R/C overexpression. On the one hand, this leads to OC inhibition and, on the other, to RANK/RANKL deactivation, which subsequently causes increased OC apoptosis and depressed OB activity resulting in BRONJ development. Legend: The red arrows indicate deactivation; the green arrows show a reversal of the effect following BP administration.

The first step in tumor necrosis factor alpha (TNF-a)-induced OC genesis occurs in the bone marrow.58 Although mature OCs erode the resorption of the bone as a focal point over the course of months to years, the lifespan of individual OCs is only a few weeks. Thus, mature OCs must be constantly replaced. With respect to OC formation, TNF-a directly stimulates the formation of mature OCs,59,60 and supports and promotes the survival of mature OCs.61 TNF-a increases the survival time of OCs to extend the duration of bone resorption. In the early stages of AIOJ/BMD/FDOJ, the situation for OCs is highly contradictory: the extremely low TNF-a values found in areas of AIOJ/BMD/FDOJ as compared to the values in healthy jawbone samples (as documented in our previous studies) indicate that any inflammatory erosion due to TNF-a supported OC formation is unlikely. Due to reduced TNF-a activation, OC formation in AIOJ/BMD/FDOJ is inhibited, which results in a fatty-degenerative morphology.62

In the same way, BPs inhibit the ability of OCs to resorb bone. They do so by suppressing farnesyl diphosphate synthetase activity, which inhibits OC recruitment and impacts the life expectancy of OCs through increased apoptosis. Where the OC function is excessively inhibited, dying OCs will not be replaced, and the capillary network of the bone will not be maintained, which leads to BRONJ.19 The ability of BPs to regulate bone turnover by suppressing OC activity has led to its widespread use in the treatment of osteoporosis, Pagets disease, humoral hypercalcemia, and in tumors metastasizing to bone.17,63 Several studies have shown the effectiveness of BPs in suppressing OC activity in arthritic bone erosions, which was comparable to the effects of OPG injections.64

The initial alkaline phosphatase (AP) situation in AIOJ/BMD/FDOJ is as follows: AP has an optimum pH in the alkaline range. The pH level of AIOJ/BMD/FDOJ areas, however, is reduced as a consequence of the proinflammatory characteristics of R/C overexpression, resulting in a chronic inflammatory state. AP activity is thus inhibited within the increasingly acidic environment of such areas. Furthermore, BPs increase R/C secretion from OBs, and the acidity of areas affected by AIOJ/BMD/FDOJ, together with an excess of R/C, leads to OC inhibition.65 At the same time, there is also reduced osteogenesis due to the suppression of AP activity,66 as well as the overexpression of R/C that is present in AIOJ/BMD/FDOJ areas and also caused by BP administration. In our model, these two factors led to OC inhibition via disturbed RANK//RANKL homeostasis. In addition, depressed OB activity and increased OC apoptosis result in BRONJ development. While the skeletal bone consolidation that results from BP administration occurs in response to increased OB activity, BRONJ develops in the jawbone when BP is administered parenterally. The reasons for these different responses to BPs have not yet been clarified. If we apply these considerations to an existing AIOJ/BMD/FDOJ area (as shown in Figure 2), then BRONJ and AIOJ/BMD/FDOJ both show suppressed AP activity with subsequent R/C overexpression.67 This leads to OC inhibition and RANK/RANKL deactivation and, subsequently, increased OC apoptosis. Decreased OB activity may ultimately lead to the development of exposed BRONJ.

Despite the similarities detailed in the section titled Osteoimmunological parameters of AIOJ/BMD/FDOJ and BRONJ with the same impact in response to BPs, BRONJ and AIOJ/BMD/FDOJ present two very different clinical pictures; different reactions to BP administration are also likely to occur.

The initial involvement of RANKL in AIOJ/BMD/FDOJ has been described in the literature as follows: pathological increases in levels of R/C and MCP-3 from activated OBs stimulate chemotactic recruitment and RANKL formation of resorptive OCs and aggravate local osteolysis. However, BP administration indirectly inhibits OC maturation by increasing OPG protein secretion and decreases transmembrane RANKL expression in human OBs. Several studies have shown that although BPs do not significantly affect RANKL gene expression, they reduce transmembrane RANKL protein expression in OBs.68,69 This shows that BPs, in addition to directly inhibiting mature OCs, prevent OC recruitment and differentiation by splitting transmembrane RANKL into OBs. OC activation and RANKL activation in areas of AIOJ/BMD/FDOJ, and OC inhibition and RANKL inhibition in BRONJ distinguish these two forms of derailed bone metabolism and thus yield different clinical results. Specifically, imperceptible fatty osteolysis of the marrow structures in AIOJ/BMD/FDOJ and painful BRONJ sequestrum arise as a result. BPs have been shown to downregulate the expression of RANKL, the OC-differentiating factor produced by OBs.70

The initial involvement of OPG in AIOJ/BMD/FDOJ is described in the literature. Since the TNF-a level found in AIOJ/BMD/FDOJ represents only 50% of the TNF-a level in healthy jawbone,36,37 the OPG enzyme that belongs to the TNF family is deactivated. In the resulting osteolysis found in areas of AIOJ/BMD/FDOJ, this leads to reduced RANKL binding and thus results in OC activation. In conclusion, data from previously published studies have suggested that BPs modulate the production of OPG by normal OBs, which may contribute to the inhibition of OC bone resorption.71 As the production of OPG increases with OB maturation, the amplification of OPG by BPs may be linked to OB differentiation via stimulatory BP effects. BPs have been shown to increase the gene expression for the decoy receptor, OPG, in human OBs.71 OPG balance is disturbed in both AIOJ/BMD/FDOJ and BRONJ, albeit in opposite ways. However, the prior imbalance of OPG activity in AIOJ/BMD/FDOJ may increase the effects associated with BP administration.

With respect to the exposed variant of BRONJ, radiographic procedures are required in order to determine the extent to which the degree of ossification has increased.72 However, the existence of this variant of BRONJ is clinically evident. In contrast, the non-exposed BRONJ variant and AIOJ/BMD/FDOJ are associated with very similar problems in terms of diagnostic imaging. As with AIOJ/BMD/FDOJ, the prevalence of this variant of BRONJ is largely underestimated as the disease is often underdiagnosed and under-reported.73 Studies have shown that almost a quarter of patients with BRONJ remain undiagnosed.74

The initial histopathological presentation of AIOJ/BMD/FDOJ found in the literature is as follows: Bouquot describes these bone modeling disorders as ischemic osteonecrosis, which is a bone disease characterized by the degeneration and death of marrow and bone due to a slow or abrupt decrease in marrow blood flow.75 Clumps of coalesced, liquefied fat (oil cysts) may be seen. Bone death is represented by a focal loss of OCs. Dark masses of calcific necrotic detritus may often be present.75 The histopathological features of AIOJ/BMD/FDOJ include necrotic adipocytes and fibrosis, but an almost complete absence of inflammatory cells.76 Additional research has shown the role of aseptic necrosis following injury or drug therapy in the pathophysiology of BRONJ. Aseptic bone necrosis, as found in AIOJ/BMD/FDOJ, has been reported as a manifestation of selected systemic diseases and also documented following operations, trauma, and immunosuppressive therapy at the site of BRONJ.77,78 The development of aseptic necrosis has been documented in the upper and lower jaw, particularly following osteotomies.79,80 Researchers have observed a relationship between oral BP use and non-specific aseptic osteonecrosis among a cohort of older cardiovascular patients.81 Other researchers have identified necrotic liquefaction, which often extend to large areas of the jaw, especially within BRONJ lesions of cancer patients, as shown using digital volume tomography (DVT)/cone beam computed tomography (CBCT).82 Research has been published on BRONJ samples that were characterized by low to moderate inflammation.83 This is in accordance with other reports of histopathological analyses of BRONJ samples.48,78,8486 Bone samples from BRONJ patients were investigated by microscopy and the presence of inflammatory infiltrates in the bone tissues was not observed.87 These studies have demonstrated that aseptic necrosis, a lack of inflammatory reactions, and empty OC lacunae are common histopathological features of AIOJ/BMD/FDOJ and BRONJ.

The diagnostic difficulties associated with BRONJ and AIOJ/BMD/FDOJ present another common feature. In order to diagnose BRONJ with imaging procedures, the Task Force Report of the American Society for Bone and Mineral Research highlights that the differential diagnosis of BRONJ should exclude other common intraoral diseases such as periodontitis, gingivitis, infectious osteomyelitis, osteoradionecrosis, neuralgia-inducing cavitational osteonecrosis (NICO), bone tumors, and metastases.15 The authors of the report thus rule out an etiological equation for diagnosing NICO and BRONJ. The current review is focused on the potential role of imaging techniques in the diagnosis of the early stages of BRONJ. A combination of clinical and radiological symptoms suggest that, while not specific to BRONJ, they may collectively be more comprehensive and representative of the bone disease process.2 The American Association of Maxillofacial Surgery accepts the use of imaging techniques when detecting BRONJ during presurgical evaluation.72 It is important for the BRONJ patient that various imaging methods be examined critically prior to being adopted for the early detection and diagnosis of BRONJ.

Figure 3 Left panel shows jawbone area 18; hematoxylin and eosin staining, magnification 200. The lower half of the image illustrates eosinophilic bone substance with empty osteocyte cavities corresponding to devitalized bone sequestrum. Middle part of the left panel: Highly irregular trabecular surfaces with a wide edging comprised of Actinomyces colonies surrounded by a wall of leukocytes. Upper part of left panel: Fibrin particles and individual lymphocytes. Right panel: Actinomyces granules visualized in a PAS reaction; the red color represents a broad band of granules in the middle. The lower edge of the right panel images once again shows a bone sequestrum and typically empty osteocyte lacunae. Diagnosis: Aseptic bone necrosis with Actinomyces colonization.

The histopathological changes in necrotic bone may be visualized with MRI scans, as with CBCT/DVT. The images detect progressive cell death and the repair response (ie, edema). As the fat cells in normal bone marrow provide high signal intensity, it may be assumed that signal changes evident in the marrow are related to the death of fat cells. Necrotic adipocytes are a morphological characteristic of AIOJ/BMD/FDOJ.76 Following the application of a contrast agent, areas of ischemia may be identified as non-enhancing regions. Cases in which fibrosis and sclerosis of the bone occur may also result in lower signal intensity. Nevertheless, the currently available data on MRI results for BRONJ are limited,96 as are those related to AIOJ/BMD/FDOJ. Studies showed positron-emission tomography (PET) as a sensitive method for diagnosis of BRONJ. Thus, PET could be useful for evaluating the severity of BRONJ.97

2D-OPG is used to identify osteopathies of the jawbone. However, this imaging technique fails to show AIOJ/BMD/FDJ areas, thus generating false-negative findings. As a result, AIOJ/BMD/FDOJ have been highly neglected in dentistry and medicine.98 Therefore, transalveolar ultrasound sonography (TAU) appears to be necessary as an additional imaging technique in order to improve the diagnosis of AIOJ/BMD/FDOJ.99,100 A newly developed TAU device (TAU-n) measures sound velocity attenuation when the bone marrow has been penetrated. An ultrasound transmitter is placed over the jaw area and a thumbnail-sized receiver is placed inside the mouth. To obtain reproducible results when measuring bone density, the transmitter and receiver are arranged in a coplanar and fixed position. The parts of the receiving unit are placed inside a patients mouth, the acoustic coupling between those parts and the alveolar ridge is performed with the aid of a semi-solid gel (Figure 3). With the receiver containing 91 piezoelectric fields, sound waves are registered and converted into a color graph of the corresponding areas of bone density (Figure 4).On the graphic visualization, green indicates healthy, dense, and solid bone, yellow indicates the presence of ischemic metabolism, and orange and red highlight areas of AIOJ/BMD/FDOJ presence.101

Figure 4 Left panel shows positioning of transmitter (outside) and receiver (enoral) in the lower jaw; the red band marks the cheek. Right panel shows the transmitter (in blue at the right) and receiver (in green at the left) in a fixed coplanar position (blue bar connecting the transmitter and receiver); semi-solid gel pads between the transmitter and the cheek on the outside of the mouth and between receiver and the alveolar ridge in the enoral position; trans-alveolar ultrasonic impulse from the transmitter to receiver (arrows in blue).

Figure 5 Inconspicuous 2D-OPG findings (left panel); suspected osteolytic processes in areas 1719 in the sagittal section of the image using DVT (right panel). Lower panel: TAU measurement from region 17 to retromolar region 19. Legend: Green areas indicate normal bone density; yellow, orange, and red areas show decreasing bone density until complete osteolysis is reached.

A clinical case of a 55-year-old patient with prostate carcinoma who was treated with parenteral BPs received an X-ray diagnosis of non-exposed BRONJ with normal intraoral findings in the right upper jawbone from area 17 to retromolar area 19. While 2D-OPG of area 18/19 showed no suspicious findings, the CBCT/DVT image demonstrated ossification irregularities and partial cavities that resembled AIOJ/BMD/FDOJ. The development and progression of BRONJ could not be reliably determined by reference to these images and it was not possible to make a differential diagnosis. In contrast, TAU-n images clearly indicated osteolysis (see Figure 4, below). The postoperative light microscopy findings from area 18/19 showed marrow with adipose tissue, significant fibrillar and myxoid degeneration of adipocytes, individual lymphocytes, and mast cells; however, no florid inflammation was observed. These are the typical histological features of AIOJ/BMD/FDOJ.76 It is worth noting, however, that there was a large bone sequestrum with empty OC cavities, highly irregular trabecular surfaces, and empty marrow spaces, with Actinomyces colonization (Figure 3).

Several reviews have indicated that light microscopy examinations were able to detect that 68.8% of BRONJ cases featured Actinomyces colonization.32 Anaerobic Actinomyces has long been associated with necrotic bone findings in BRONJ lesions.102 Actinomyces colonization is thus a top priority as a possible pathological trigger with respect to BRONJ. Since we have not identified bacterial colonization in areas of AIOJ/BMD/FDOJ in our own studies,103 an accompanying secondary Actinomyces colonization seems to be an additional prerequisite for the development of BRONJ from an area of AIOJ/BMD/FDOJ in response to BP administration.

Table 1 displays all studies and their impact on the research question based on the inclusion and exclusion criteria in literature review.

Table 1 The Table Displays the Criteria for Inclusion of Specific Manuscripts in Our Research. Exclusion Criteria Were Unspecific Reviews Concentrating on Exposed BRONJ Only

Can hitherto little-known, yet according to our clinical experience37,76 epidemiologically widespread AIOJ/BMD/FDOJ represent cofactors in the development of BRONJ? The development of biological processes takes place in different stages and during various phases of transition. This also seems to be the case for BRONJ, as the exposed form found in the maxillofacial region represents the final, late-stage form of the NE-BRONJ variant. The focus of our study is thus on the early stage of BRONJ (Stage 0) without exposed bone, as based on the recommendations of the American Association of Oral and Maxillofacial Surgeons.5,20,104 Our hypothesis considers the NE-BRONJ variant as one stage of development featuring an unrecognized BMD that is characteristic of AIOJ/BMD/FDOJ and amplified by BP administration. The cumulative effects of BPs on pre-existing AIOJ/BMD/FDOJ support this premise. The relationship between AIOJ/BMD/FDOJ and the administration of BPs (as shown in Figure 6) leads, etiologically, to the non-exposed BRONJ variant, which is less clearly described in the literature than the late-stage form of BRONJ, and also results in considerable oral impairment.

Figure 6 Overview of the individual osteoimmunological signal cascades present in AIOJ/BMD/FDOJ and their conversion or amplification following BP administration, resulting in the development of BRONJ. Legend: A pair of arrows, one red and one green, indicates the reinforcement or, in one instance, the reversal of the typical overexpression or inhibition found in AIOJ/BMD/FDOJ following BP administration.

As BPs and AIOJ/BMD/FDOJ exert the same effects, resulting in the hyperfunctioning of R/C expression, OB activity, hypoxia/ischemia, and the inhibition of OC activity, vascularization, and AP activity, AIOJ/BMD/FDOJ may be regarded as a prerequisite to the formation of BRONJ. Changes in silent AIOJ/BMD/FDOJ processes, including strongly inhibited OC production, reduced RANKL activity, and increased OPG activity, appear to induce the occurrence of BRONJ. Figure 7 presents a hypothetical three-step model detailing the basic stages for the development of BRONJ at AIOJ/BMD/FDOJ areas. Regions with fatty-degenerative changes may be the focal point for the subsequent development of BRONJ, as such changes may constitute an additional risk factor. This is consistent with the hypothesis described in the literature, whereby bone necrosis precedes clinically evident ONJ that is exposed through the oral mucosa.78,105 Regions featuring subclinical changes and necrotic bone may represent significant risk factors in the development of BRONJ.104 Further, it is known that patients at each stage exhibit a very different bone composition.104

Figure 7 Three-step model for the development of BRONJ beginning with undetected AIOJ/BMD/FDOJ followed by the development of the NE-BRONJ variant, and finally by BRONJ.Notes: Exposed bone BNOJ (left panel). Bony sequestrum BRONJ (right panel). Figure courtesy of Professor J Bouquot.

The prevention of BRONJ is of paramount importance and has been repeatedly emphasized.106108 Thus, BPs should not be regarded as the sole cause of osteonecrosis. The results of this study indicate that unresolved areas of wound healing at extraction sites especially in former wisdom tooth areas may directly contribute to the pathogenesis of BRONJ. Other research has already described the involvement of the jaw in BRONJ as opposed to other bone sites.109 This may be because BPs are preferentially deposited in bones with high turnover rates such as the jawbone. The jawbone also presents with hidden conditions that according to our hypothesis share common characteristics with those found in AIOJ/BMD/FDOJ. Under the influence of BPs, areas of AIOJ/BMD/FDOJ may develop the pathological features of BRONJ. Efforts to prevent BRONJ, therefore, should not ignore the fact that BRONJ and AIOJ/BMD/FDOJ share similar osteoimmunological characteristics with respect to amplifying or reversing derailed signal cascades. Since AIOJ/BMD/FDOJ represent chronic, subclinical states, the sudden formation of BRONJ may be interpreted as a subsequent acute event. The early detection of BRONJ (as well as AIOJ/BMD/FDOJ) using X-ray techniques appears to be difficult. A new risk-benefit analysis should be considered: Patients should be screened for hidden oral risk factors, such as AIOJ/BMD/FDOJ. Thus, TAU may be used to measure bone density and fill this diagnostic gap. When parenteral BP therapy is administered, periodontal prophylaxis and tooth restoration should take precedence;110,111 furthermore, AIOJ/BMD/FDOJ should be diagnosed first, preferably (and accurately) with TAU-n, and then surgically eliminated. The formation of difficult-to-treat BRONJ could be avoided in certain cases if the exacerbation of pre-existing areas of AIOJ/BMD/FDOJ is prevented before initiating anti-tumorigenic BP therapy. Surgical opening of the cortex, removal of ischemic marrow, and accompanying wound care represent the only way to address cases of AIOJ/BMD/FDOJ.112 Consultation with an oncologist is mandatory, as the oncologist may insist on radiation therapy and the prevention of osteoradionecrosis of the jawbones via tooth restoration. To the best of our knowledge, we have highlighted, for the first time, the possible impact chains flowing from AIOJ/BMD/FDOJ and leading to the development of NE-BRONJ and further to exposed BRONJ. We also support the hypothesis presented herein with scientific data from the available literature. Due to the lack of clinical studies investigating these impact chains, multiple studies are necessary to elucidate the hypothesized relationships.

AIOJ, aseptic-ischemic osteonecrosis of the jawbone; BMD, bone marrow defects; BRONJ, bisphosphonate (BP)-related osteonecrosis of the jaw; CBCT, cone beam computed tomography; CCL5, chemokine (C-C motif) ligand 5; DVT, digital volume tomography; FDOJ, fatty-degenerative osteonecrosis/osteolysis of the jawbone; HU, hounsfield units; OPG, orthopantomogram; R/C, RANTES/CCL5; RANTES, regulated on activation, normal T cell expressed and secreted; TAU, transalveolar ultrasonography; TAU-n, new transalveolar ultrasonography device.

Hereby we confirm that written informed consent has been provided by the patient to have the case details and any accompanying images published. The data were collected as part of the normal everyday medical care of the patients and evaluated retrospectively. Institutional approval was not required to publish the case details.

English language editing of this manuscript was provided by Journal Prep Services. Additional English language editing was provided by Natasha Gabriel.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

The corresponding author, Johann Lechner, is the holder of a patent used in the TAU-n apparatus and its associated software and reports a patent CaviTAU licensed to Dr. Johann Lechner. Bernd Zimmermann is an employee of QINNO. The authors report no other potential conflicts of interest for this work.

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27. Gnant M, Mlineritsch B, Stoeger H, et al. Adjuvant endocrine therapy plus zoledronic acid in premenopausal women with early-stage breast cancer: 62-month follow-up from the ABCSG-12 randomised trial. Lancet Oncol. 2011;12:631641. doi:10.1016/S1470-2045(11)70122-X.

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[Full text] Osteonecrosis of the Jaw Beyond Bisphosphonates: Are There Any Unknown | CCIDE - Dove Medical Press

Bone Marrow Stem Cells Comments Off on [Full text] Osteonecrosis of the Jaw Beyond Bisphosphonates: Are There Any Unknown | CCIDE – Dove Medical Press | January 22nd, 2021

BrainStorm Cell Therapeutics has announced that its NurOwn (MSC-NTF cell) derived exosomes provided significant improvement in lung function and histology in an acute respiratory distress syndrome (ARDS) mouse model, in a preclinical study.

Mesenchymal stem cell (MSC)-derived exosomes can penetrate deep into tissues and deliver immunomodulatory molecules effectively.

A type of respiratory failure, ARDS is linked to Covid-19 and is mediated by dysregulated cytokine production.

Intratracheal administration of NurOwn derived exosomes provided a statistically significant reduction in lung disease severity score, the study data showed.

Furthermore, improvements in lipopolysaccharide (LPS)-induced ARDS markers like lung function, fibrin presence, neutrophil accumulation, cytokine expression and oxygenation levels in the blood, were observed.

These improvements were significantly superior to those noticed following nave MSC-derived exosome administration.

BrainStorm Research and Development vice-president Dr Revital Aricha said: These exciting preclinical data suggest that NurOwn derived exosomes have the potential to treat Covid-19-induced ARDS or other severe respiratory complications and that they are more effective than exosomes isolated from nave MSCs at combatting the various symptoms of the syndrome.

This publication in a highly regarded journal provides important validation for the scientific advances and significance of BrainStorms preclinical research programs, including on our exosome-based technology platform.

The NurOwn technology platform (autologous MSC-NTF cells) represents a promising investigational therapeutic approach to targeting disease pathways important in neurodegenerative disorders.

GlobalData's TMT Themes 2021 Report tells you everything you need to know about disruptive tech themes and which companies are best placed to help you digitally transform your business.

MSC-NTF cells are made from autologous, bone marrow-derived MSCs expanded and separated ex vivo.

Brainstorm CEO Chaim Lebovits said: While our primary focus is on advancing NurOwn towards regulatory approval in ALS, we continue to evaluate the potential of our exosome-based platform to address unmet medical needs.

In December 2019, the company received a recommendation from the independent Data Safety Monitoring Board (DSMB) to continue the Phase II clinical trial of NurOwn in progressive multiple sclerosis patients.

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BrainStorm's Covid-19 ARDS treatment improves lung function in study - Clinical Trials Arena

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Regenerative medicine contributed to patient care in 2020 more than ever before, bolstered by synergies in research, practice and education. Mayo Clinics Center for Regenerative Medicine is at the forefront of a biotherapy revolution in which health care advances from treating disease to restoring health.

The centrality of the body to regenerate itself is paving the way for new horizons in regenerative care. The triad of protecting against disease, preventing disease progression and promoting healing is at the core of the regenerative vision, says Andre Terzic, M.D., Ph.D., director of Mayo Clinics Center for Regenerative Medicine. To this end, the regenerative toolkit has grown more robust over the past year with new technologies now available to boost the bodys ability to repair and restore health of an organ and importantly of the patient as a whole.

The convergence of research, practice and education, empowered by strong innovation and advanced biomanufacturing, is creating an increased level of readiness for applying validated regenerative science to new areas of health care, Dr. Terzic says.

Practice advancement

A deeper understanding of the biology of health and disease is driving the ongoing regenerative medicine evolution.

The remarkable progress in science that is advancing our fundamental comprehension of both health and disease has guided the informed and responsible development of patient-ready curative strategies, says Dr. Terzic.

New discoveries at Mayo Clinic that may shape future practice include:

Validating safety and efficacy of

stem cell therapy for heart failure. The largest regenerative medicine clinical trial to date for heart failure, spanning 39 medical centers and 315 patients from 10 countries, validated the long-term safety of stem cell therapy. The late-stage research found stem cell therapy shows particular benefit for patients with advanced left ventricular enlargement. This Mayo Clinic-led study offers guidance on which patients are most likely

to respond to stem cell therapy for heart failure.

Uncovering stem cell activation of healing. Mayo Clinic researchers uncovered stem cell-activated molecular mechanisms of healing after a heart attack. Stem cells restored the makeup of failing cardiac muscle back to its condition before the heart attack, providing an intimate blueprint of how they may work to heal diseased tissue. This research offers utility to delineate and interpret complex regenerative outcomes.

Discovering a molecular light switch. Mayo Clinic research discovered a molecular switch that turns on a substance that repairs neurological damage. This early research could bolster a therapy approved by the Food and Drug Administration, and that could lead to new strategies for treating diseases of the central nervous system such as multiple sclerosis.

The federal regulatory environment is making it possible to more seamlessly integrate new discoveries into the practice. The 21st Century Cures Act, for example, seeks to create an accelerated path to market for safe, validated procedures that could provide new therapies for patients with serious conditions.

To read the rest of this article on the Center for Regenerative Medicine blog, visit http://www.regenerativemedicineblog.mayoclinic.org.

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Regenerative medicine is advancing health care in diverse ways - Hometown Focus

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Bespoke Extracts Announces $100K Investment From CEO and Addition of New Brand Ambassador, UFC Fighter Maryna Moroz

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DUBLIN, Ireland and BRIDGEWATER, N.J., Jan. 21, 2021 (GLOBE NEWSWIRE) -- Amarin Corporation plc (NASDAQ:AMRN) today announced that the Chinese Society of Cardiology (CSC) has included icosapent ethyl in its updated Guidelines for Primary Prevention of Cardiovascular Diseases for 2021 as published in the Chinese Journal of Cardiovascular Diseases. The guideline authors include “icosapent ethyl 2 grams twice a day (as studied in REDUCE-IT®) as a treatment consideration to further lower atherosclerotic cardiovascular disease (ASCVD) in the appropriate patient population.”1

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Icosapent Ethyl Included in the Chinese Society of Cardiology (CSC) Updated Guidelines for Primary Prevention of Cardiovascular Diseases

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THIS ANNOUNCEMENT IS NOT FOR DISTRIBUTION, DIRECTLY OR INDIRECTLY, IN THE UNITED STATES OF AMERICA, AUSTRALIA, CANADA, JAPAN, SOUTH AFRICA OR ANY OTHER JURISDICTION WHERE TO DO SO WOULD BE PROHIBITED BY APPLICABLE LAW

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MDxHealth Successfully Completes a EUR 25.0 Million (USD 30.4 Million)(1) Capital Increase

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Immutep’s Collaboration and Exclusive License with GSK Remains in Place Immutep’s Collaboration and Exclusive License with GSK Remains in Place

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Ulcerative Colitis Phase II Study of GSK2831781 Discontinued

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Immutep Quarterly Activities Report

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Amsterdam, The Netherlands, January 22, 2021 – Kiadis Pharma N.V. ("Kiadis" or the "Company") (Euronext Amsterdam and Brussels: KDS), a clinical-stage biopharmaceutical company developing innovative NK-cell-based medicines for the treatment of life-threatening diseases, today announces that four abstracts related to its K-NK-cell therapy platform were accepted for presentation at the TCT Meetings, the Transplantation & Cellular Therapy Meetings of the American Society of Transplantation and Cellular Therapy (ASTCT) and Center for International Blood & Marrow Transplant Research (CIBMTR), which is being held virtually from February 8–12, 2021.

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Kiadis announces multiple abstracts related to its K-NK-cell therapy platform have been accepted for presentation at TCT, the Combined Transplantation...

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Nicox Analyst Coverage Initiated by Edison Investment Research

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ONO Receives a Manufacturing and Marketing Approval of Adlumiz® (Anamorelin), a Ghrelin Receptor Agonist for the Treatment of Cancer Cachexia in...

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Oslo (Norway), 22 January 2021 – PCI Biotech (OSE: PCIB), a clinical-stage biopharma company developing innovative therapeutics that address significant unmet medical needs in cancer today announced that it will present at the 12th Annual RNA Therapeutics Virtual Conference, a UK based online event taking place February 10-11, 2021. The 2021 conference is set to explore the latest developments in RNA delivery agents and RNA-based therapeutics with the latest case studies on advanced mRNA technologies, oligonucleotide delivery, therapeutic applications and future trends and innovations. PCI Biotech is also a sponsor of the event.

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PCI Biotech to present at RNA Therapeutics Virtual Conference

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BioCryst Announces Approval of ORLADEYO™ (berotralstat) in Japan for the Prophylactic Treatment of Hereditary Angioedema

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DENVER, Jan. 22, 2021 (GLOBE NEWSWIRE) -- Mydecine Innovations Group (CSE: MYCO) (OTC: MYCOF) (FSE: 0NFA) (“Mydecine” or the “Company’), an emerging biopharma and life sciences company committed to the research, development, and acceptance of alternative nature-sourced medicine for mainstream use, has been included in the first-ever Psychedelics Exchanged Traded Fund (ETF).

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Mydecine Innovations Group Included in First-Ever Psychedelics ETF

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Poster to be presented at the 2021 Society for Laboratory Automation and Screening Digital International Conference and Exhibition.

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aTyr Pharma to Present Poster Highlighting Research Approach for Identifying Receptor Targets for Extracellular tRNA Synthetases

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LA JOLLA, Calif., Jan. 22, 2021 (GLOBE NEWSWIRE) -- Equillium, Inc. (Nasdaq: EQ) a clinical-stage biotechnology company developing itolizumab to treat severe autoimmune and inflammatory disorders, today announced that interim data from the Phase 1b/2 EQUATE study of itolizumab in acute graft-versus-host disease (aGVHD) has been accepted as a late-breaking oral presentation at the 2021 TCT Meetings Digital Experience, being held February 8-12, 2021.

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Equillium Announces Acceptance of Late-Breaking Abstract for Oral Presentation of Interim Data from EQUATE Study in acute GVHD at the 2021 TCT...

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Report from the Extraordinary General Meeting of Immunicum AB (publ) on 22 January 2021

Global News Feed Comments Off on Report from the Extraordinary General Meeting of Immunicum AB (publ) on 22 January 2021 | January 22nd, 2021

Funded by Amgen, Astellas, Bristol Myers Squibb, GSK, Janssen, Lilly, Pfizer, Roche, Sanofi and Takeda

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Ten Leading BioPharma Companies Announce Formation of Accumulus Synergy to Develop Global Data Sharing Platform

Global News Feed Comments Off on Ten Leading BioPharma Companies Announce Formation of Accumulus Synergy to Develop Global Data Sharing Platform | January 22nd, 2021