Bone Marrow Mesenchymal Stem Cells Slow The Degeneration Of Nucleus Pulposus Cells Through NF-κB Pathway

Objective：To investigate the mechanism of slowing NPCs degeneration by BMSCs.Methods: The experiment was divided into three groups: NPCs were cocultured withBMSCs at the ratio of1:1, an equal number of BMSCs or NPCs were used as control. Cellproliferation were determined by CCK8methods at3、5、7、9days. At5、8、11、14daysRT-PCR (reverse transcriptase-polymerase chain reaction) were used to assay the geneexpression levels of aggrecan、collagen type II and SOX-9; content of TGF-β l weredetected by ELISA methods; content of NF-B were detected by Western-blot methods；IHC staining was carried out to evaluate the collagen type II synthesis.Results: BMSCs were successfully isolated and CD29~+、CD90~+、CD34~--weredemonstrated. The ability of cell proliferation of co-cultured group was greater than theother groups after3days. The expression of SOX-9of co-cultured group was significantlyhigher than the other groups after11days and the expression of aggrecan and collagentype II of co-cultured group were significantly higher than the other groups after14days.The content of TGF-β l of co-cultured group was higher than the other groups after11days,comparatively the content of NF-B was lower than the other groups after11days.Immunohistochemical stains of collagen type II in pure NPCs culture group were allpositive at each time point and in co-cultured group it showed positive at5、8、11days andbecame strong positive at14days.Conclusion: Make BMSCs and NPCs coculture can promote the expression ofaggrecan、collagen type II and SOX-9of NPCs. BMSCs delaying NPCs degeneration through upregulating TGF-β l thus inhibiting the NF-κB pathway.