ROLE OF HUC-MSCS AND THEIR CARTILAGE PROGENITOR CELL DERIVATIVES ON PAIN RELIEF IN THE ANIMAL MODEL OF IVD

Objective: To investigate the effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) and their cartilage progenitor cell derivatives on pain relief in the animal model of intervertebral disc (IVD) degeneration. Methods: hUC-MSCs were differentiated into chondroprogenitor cells by cartilage induction medium in this study. The rat tail IVD model was established with three consecutive tail intervertebral discs, and the levels of molecular markers of pain and inflammatory response evaluation were detected by fluorescence quantitative PCR (qPCR). Histological staining was used to evaluate regeneration degree. Results: The gene expression of sex determining region Y-box 9(SOX9), transforming growth factor-I3 1 (TGF-I3 1), Aggrecan (ACAN), bone morphogenetic protein -2(BMP-2) and growth differ-entiation factor -5(GDF-5) coud be seen after chondrocyte progenitor cells were induced. Immunocy-tochemical staining showed that chondrogenic proteins SOX9, TGF-I31, TGF-I32 and type II collagen were positive. In vivo experiments showed that the survival, homing and distribution of transplanted cartilage progenitor cells in IVD were superior to those of normal bone marrow mesenchymal stem cells (MSC). On the 5th day after transplantation of chondrocyte progenitor cells, pain and inflammation genes were expressed and showed obvious immune response. The fluorescence colocalization results of SOX9, TGF-I31 and TGF-I32 indicated that the transplanted marker MSC and the induced cartilage progenitor cells differentiated into functional nucleus pulposus (NP) cells. Histological staining showed that the cell structure and maintenance degree of cell morphology of NP cells was better than that of degenerated intervertebral disc. Conclusion: Chondroprogenitor cells derived from hUC-MSCs have better regeneration potential than normal MSCs. Transplantation of hUC-MSCs can effectively down-regulate the expression of pain and inflammation genes in degenerative IVD.