Stem cell therapy: is there a future for reconstruction of large bone defects?

AbstractWhile bone has an inherent capacity to heal itself, it is very difficult to reconstitute large bone defects. Regenerative medicine, including stem cell implantation, has been studied as a novel solution to treat these conditions. However, when the local vascularity is impaired, even the transplanted cells undergo rapid necrosis before differentiating into osteoblasts and regenerating bone. Thus, to increase the effectiveness of stem cell transplantation, it is quintessential to improve the viability of the implanted stem cells. In this study, given that the regulation of glucose may hold the key to stem cell survival and osteogenic differentiation, we investigated the molecules that can replace the effect of glucose under ischemic microenvironment of stem cell transplantation in large bone defects. By analyzing differentially expressed genes under glucose-supplemented and glucose-free conditions, we explored markers such as methyltransferase-like protein 7A (METTL7A) that are potentially related to cell survival and osteogenic differentiation. Overexpression of METTL7A gene enhanced the osteogenic differentiation and viability of human bone marrow stem cells (hBMSCs) in glucose-free conditions. When the in vivo effectiveness of METTL7A-transfected cells in bone regeneration was explored in a rat model of critical-size segmental long-bone defect, METTL7A-transfected hBMSCs showed significantly better regenerative potential than the control vector-transfected hBMSCs. DNA methylation profiles showed a large difference in methylation status of genes related to osteogenesis and cell survival between hBMSCs cultured in glucose-supplemented condition and those cultured in glucose-free condition. Interestingly, METTL7A overexpression altered the methylation status of related genes to favor osteogenic differentiation and cell survival. In conclusion, it is suggested that a novel factor METTL7A enhances osteogenic differentiation and viability of hBMSCs by regulating the methylation status of genes related to osteogenesis or survival.

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Regenerative Medicine in Orthopaedics and Trauma: Challenges, Regulation and Ethical Issues

Ortopedia Traumatologia Rehabilitacja ◽

10.5604/01.3001.0012.0764 ◽

2018 ◽

Vol 20 (3) ◽

pp. 173-180 ◽

Cited By ~ 2

Author(s):

Radoslav Zamborsky ◽

Miroslav Kilian ◽

Maria Csobonyeiova ◽

Lubos Danisovic

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Regenerative Medicine ◽

Cell Therapy ◽

Stem Cell Therapy ◽

Ethical Issues ◽

Cell Types ◽

Bone Defects ◽

Cord Injury ◽

Critical Bone Defects

The ability of stem cells to self-renew and differentiate into cell types of different lineages forms the basis of regenerative medicine, which focuses on repairing or regenerating damaged or diseased tissues. This has a huge potential to revolutionize medicine. It is anticipated that in future, stem cell therapy will be able to restore function in all major organs. Intensive research has been on-going to bring stem cell therapy from bench to bedside as it holds promise of widespread applications in different areas of medicine. This is also applicable to orthopaedics, where stem cell transplantation could benefit complications like spinal cord injury, critical bone defects, cartilage repair or degenerative disc disorders. Stem cell therapy has a potential to change the field of orthopaedics from surgical replacements and reconstructions to a field of regeneration and prevention. This article summarizes advances in stem cell applications in orthopaedics as well as discussing regulation and ethical issues related to the use of stem cells.

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