Korean researchers have found a signal transduction system that modulates the treatment of mesenchymal stem cells and immune control functions, opening the way for treating graft-versus-host disease treatment.

Mesenchymal stem cells divide into various cells, have immunomodulatory functions, and are the primary cell sources for stem cell therapy.

Graft-versus-host disease is a fatal disease that leads to death after an allogeneic blood transfusion or bone marrow transplantation. Although there are many clinical trials underway worldwide to treat the symptom, there are no applicable treatments besides alleviating symptoms with high-dose steroids.

The team, led by Professor Shin Dong-myeong of the Department of Biomedical Sciences at Asan Medical Center, discovered that the CREB1 (CAMP responsive element binding protein 1) signaling system activates the treatment and immune control functions of mesenchymal stem cells.

The team administered a therapeutic agent made by upgrading mesenchymal stem cells to graft-versus-host disease mice, and found that it alleviated anorexia symptoms and reduced the weight loss rate by 30 percent while increasing the survival rate by 30 percent.

When developing a cell therapy product, researchers have to cultivate the stem cells in vitro. Thus it is very likely that it will impair stem cell functions due to free radicals generated in the cells. To prevent the deterioration of stem cell function, it is necessary to improve the stem cell function in vitro culture, prevent stem cell oxidation, and increase the antioxidant capacity of the cell itself.

Until now, there was a lack of specific evidence and understanding of how stem cells regulate glutathione, an indicator of antioxidant capacity. Therefore, it was difficult to prevent stem cell dysfunction and oxidation.

Professor Shin's team developed experimental techniques that can monitor and quantify glutathione in real-time and confirmed that the CREB1 signaling system regulated the amount and activity of glutathione.

By activating the CREB1 signaling system, the team found that the process also activated nuclear factor erythroid 2-related factor 2 (NRF2) protein, which maintains the antioxidant capacity of mesenchymal stem cells and the increase of both the expression levels of peroxiredoxin-1 (PRDX1) and glutamate-cysteine ligase modifier subunit (GCLM) protein, which synthesize glutathione and are antioxidant activity indicators.

As a result, the team confirmed that its method was effective in treating the graft-versus-host disease.

"Based on this study, we have secured a technological foundation to advance stem cell treatment by controlling the antioxidant capacity of stem cells," Professor Shin said.

If this technology makes a high-purity and high-quality stem cell treatment, the team expects that it will be a step toward developing a graft-versus-host disease treatment and overcoming various intractable diseases such as nervous system diseases and inflammatory diseases with high medical demand, Shin added.

The results of the study were published in the journal, Science Advances.

corea022@docdocdoc.co.kr

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AMC to use stem cell therapy in treating graft-versus-host disease - Korea Biomedical Review