The Effects Of Vitamin D On Expression Of The Matrix Gla Protein In Postmenopausal Osteoporosis

Objective:1. To investigate the relationship of serum 25(OH)D3 level and serum MGP in postmenopausal osteoporosis. 2. To observe the effects of1,25-Dihydroxyvitamin D3 on Wnt/β-catenin signaling pathways and expression of MGP in human osteosarcoma cells line(MG63) in vitro, to investigate the potential role of vitamin D in postmenopausal osteoporosis.Methods: 1. 125 postmenopausal female subjects were enrolled in the second affiliated hospital of Nanchang university from Apr 2013 to Feb 2015. According to bone mineral density, groups were divided to normal bone mass, low bone mass,osteoporosis. Measure the serum 25(OH) D3 levels and serum MGP concentrations.According to serum 25(OH) D3 levels, groups were divided to deficiency group,insufficiency group, adequacy group. 2. Human osteosarcoma MG63 cells were carried out the following drug intervention respectively: 1,25(OH)2D310-8 mol/L,DKK-1( Dickkopf-1) 200 ng/ml, 1,25(OH)2D310-8mol/l + DKK-1 200 ng/ml intervened for 48 hours,all referred 1% BSA( bovine serum albumin)+serum-free MEM culture as the control group, then total RNA and protein were extracted and examined by Real-Time quantitative RT-PCR and Western blot to measure the mRNA and protein expression of β-catenin, Runx2, LRP5, MGP in MG63 cells.Results: 1. In postmenopausal osteoporosis, serum MGP in the low bone mass,osteoporosis group decreased significantly compared to that in the normal bone mass group, the difference was statistically significant(P <0.05), the serum MGP and bone mineral density was positively correlated. 2. In postmenopausal osteoporosis, serum MGP in the deficiency group, insufficiency group decreased significantly compared to that in the adequacy group, the difference was statistically significant(P <0.05),the serum MGP and 25(OH) D3 was positively correlated. 3. 1,25(OH)2D3significantly up-regulated the expression of the classic Wnt/β-catenin signaling pathway associated protein such as β-catenin, Runx2, LRP5 and MGP. DKK-1down-regulated the expression of β-catenin, LRP5, Runx2, MGP, the difference was statistically significant(P <0.05).Conclusion: 1. In postmenopausal osteoporosis, the serum MGP and bone mineral density was positively correlated. 2. In postmenopausal osteoporosis, the serum MGP and 25(OH) D3 was positively correlated. 3. 1,25(OH)2D3 may regulated the expression of MGP through the classic Wnt/β-catenin signaling pathway.