Effects of calcium-sensitive receptors on chondrogenic differentiation of rat bone marrow mesenchymal stem cells.

The purpose of this study was to investigate the role of Calcium-Sensing Receptor in the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) and to provide a new target for cartilage defect repair. BMSCs were cultured in vitro, and cultured in the complete culture medium with gradient concentration of calcium sensitive receptor inhibitor and activator, and the optimum dose was selected by CCK-8 experiment. The experiment was divided into four groups. After 7, 14 and 21 days of intervention, the intracellular calcium concentration was detected by laser confocal microscope, the differentiation of cartilage was detected by toluidine blue staining, and the expression of cartilage marker proteins (Col- II, Agg and Sox9) was detected by immunocytochemical staining and Western Blot. The CCK-8 assay results showed that the optimal concentrations of Gd and NPS were 300 μM and 10 μM, respectively. After 7, 14, and 21 days of culture, intracellular calcium fluorescence decreased, with notably higher cartilage differentiation in the NPS inhibitor group. Col-II, Agg and Sox9 chondrocyte marker proteins increased with culture time in all groups, with significantly higher levels in the inhibitor group compared to others, followed by the cartilage induction solution group, and then the activator group. Inhibition of calcium sensitive receptors can promote chondrogenic differentiation of rat BMSCs by regulating Sox9, affecting Col- II and Agg.