AUTHOR=Khalid Shumaila , Ekram Sobia , Ramzan Faiza , Salim Asmat , Khan Irfan 

TITLE=Co-regulation of Sox9 and TGFβ1 transcription factors in mesenchymal stem cells regenerated the intervertebral disc degeneration

JOURNAL=Frontiers in Medicine

VOLUME=10

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1127303

DOI=10.3389/fmed.2023.1127303

ISSN=2296-858X

ABSTRACT=<sec><title>Background</title><p>Intervertebral disc (IVD) shows aging and degenerative changes earlier than any other body connective tissue. Its repair and regeneration provide a considerable challenge in regenerative medicine due to its high degree of infrastructure and mechanical complexity. Mesenchymal stem cells, due to their tissue resurfacing potential, represent many explanatory pathways to regenerate a tissue breakdown.</p></sec><sec><title>Methods</title><p>This study was undertaken to evaluate the co-regulation of <italic>Sox9</italic> and <italic>TGF</italic>β<italic>1</italic> in differentiating human umbilical cord mesenchymal stem cells (hUC-MSC) into chondrocytes. The combinatorial impact of <italic>Sox9</italic> and <italic>TGF</italic>β<italic>1</italic> on hUC-MSCs was examined <italic>in vitro</italic> by gene expression and immunocytochemical staining. In <italic>in vivo</italic>, an animal model of IVD degeneration was established under a fluoroscopic guided system through needle puncture of the caudal disc. Normal and transfected MSCs were transplanted. Oxidative stress, pain, and inflammatory markers were evaluated by qPCR. Disc height index (DHI), water content, and gag content were analyzed. Histological examinations were performed to evaluate the degree of regeneration.</p></sec><sec><title>Results</title><p>hUC-MSC transfected with <italic>Sox9</italic>+<italic>TGF</italic>β<italic>1</italic> showed a noticeable morphological appearance of a chondrocyte, and highly expressed chondrogenic markers (<italic>aggrecan, Sox9, TGF</italic>β<italic>1, TGF</italic>β<italic>2</italic>, and type II collagens) after transfection. Histological observation demonstrated that cartilage regeneration, extracellular matrix synthesis, and collagen remodeling were significant upon staining with H&amp;E, Alcian blue, and Masson's trichrome stain on day 14. Additionally, oxidative stress, pain, and inflammatory markers were positively downregulated in the animals transplanted with <italic>Sox9</italic> and <italic>TGF</italic>β<italic>1</italic> transfected MSCs.</p></sec><sec><title>Conclusion</title><p>These findings indicate that the combinatorial effect of <italic>Sox9</italic> and <italic>TGF</italic>β<italic>1</italic> substantially accelerates the chondrogenesis in hUC-MSCs. Cartilage regeneration and matrix synthesis were significantly enhanced. Therefore, a synergistic effect of <italic>Sox9</italic> and <italic>TGF</italic>β<italic>1</italic> could be an immense therapeutic combination in the tissue engineering of cartilaginous joint bio-prostheses and a novel candidate for cartilage stabilization.</p></sec>