The Effects Of 1, 25(OH)2D3 And Calcitonin On Cell Proliferation And OPG/RANKL/RANK Expression In Mouse Osteoblasts And Chondrocytes

Objectives: To investigate the effects of 1,25(OH)2D3 and Calcitonin on cell proliferation , OPG / RANKL expression of mouse osteoblast and chondrocyte and RANK expression of mouse femoral Metaphysis. Methods: sterile articular cartilage and calvaria of mouse were taken from 30 newborn mouse, the osteoblast and chondrocyte were separated by enzyme digestion methods , 1,25(OH)2D3 and Calcitonin in different concentrations were administrated into culture medium, the effects of 1,25(OH)2D3, Calcitonin on cell proliferation of mouse osteoblasts and chondrocytes were examined. The OPG / RANKL expression and OPG protein secretion were examined by RT-PCR and ELISA methods respectively. The expression of RANK in ovariectomized rats femoral Metaphysis was examined with IHC. Results: cell proliferation of osteoblasts and chondrocytes was inhibited by 1,25(OH)2D3, but it's promoted by calcitonin; OPG mRNA expression of osteoblasts and chondrocytes were inhibited and RANKL mRNA expression in osteoblasts was promoted by 1,25(OH)2D3; however, OPG mRNA expression and OPG protein secretion of osteoblasts promoted was found, while RANKL mRNA expression was inhibited by calcitonin; no significant change of OPG mRNA and decreased RANKL mRNA expression were observed in chondrocytes calcitonin - treated. The periosteum of the femoral Metaphysis in aged rat, the RANK mRNA expressed was less than those in the bone of 12-week-old rat, in the trabecular bones, the expressing of RANK was stronger in the ovariectomized rats than in the sham-groups. Conclusion: 1,25(OH)2D3 inhibited cell proliferation and OPG mRNA expression and promoted RANKL mRNA in osteoblasts and chondrocytes; calcitonin increased cell proliferation and OPG mRNA expression in osteoblasts...