Experimental Study On Osteogenenic Potential Of BMSCs Of OVX Goats And Expression Of OPG And IGF-1 Induced By RhBMP-2

Postmenopausal osteoporosis (PMO) is a prevalent metabolic bone disease which threatens the health of elder women seriously. The pathogenesis remains unclear. Bone metabolic disease induced by the decline of estrogen is the main reason, but the direct reason of PMO is the broken of balance of bone formation and bone absorption. The treatment of osteoporosis including inhibiting bone absorption,accelerating bone formation and general treatment. There are more studies focused on the mechanism of inhibting bone absorption than that on the accelerating osteogenesis. How to increase the bone mineral density of osteoporosis and prevent osteoporotic fracture is an exigent question.Recent researches have proved that bone morphogenetic proteins play a very important role in the process of osteogenesis. More attentions have been paid on the mechanism of BMPs in the obstacle of osteogenesis. Researches found that BMPs declined obviously while BMP antibodies increased in serum of patients suffered from osteoporosis; BMP-2 mRNA decreased in cancellous bone of ovariectomized rats. All these results provided theory basis for treating osteoporosis using BMPs. But can BMP initiate the normal osteogenetic process and whether the target cell of BMPs in osteoporosis—BMSCs keeps excellent reaction to BMPs? Whether other growth factors of osteogenesis can normally expressed in the process of differatiation and proliferation? Can exogenous BMP be injected on the local site which is prone to fracture, such as femoral neck,distal radius, to enhance local bone density and strength to prevent osteoporosis fractures?We established an animal model of PMO by ovariectomized goats. The following researches were carried: 1)Bone marrow stromal stem cells were isolated from the goat of control group and of ovariectomized group by means of full bone marrow culturing method. The growth characteristics of these two group cells were compared. 2)BMSCs were induced by osteogenic inducer, adipogenic inducer and rhBMP2 respectivecly. The differentination to osteoblasts or adipocytes were observed to compare the potential of osteogenic and adipogenic of BMSCs. 3) After having been induced by rhBMP, immunohistochemistry and Image Analysis were used to detect the expression of IGF-1 and OPG to in both two groups.The results revealed that:1. The PMO model was successfully established at 7 monthes post-OVX.2. BMSCs of OVX group growth slowly and have lower proliferation potential than that of control group.3. Osteogenic potential of BMSCs of OVX group decreased, but adipogenic potential increased significantly than that of control group. After induced by rhBMP2, no significant difference of osteogenic potential was found between the two groups.4. After induced by rhBMP, the expression of IGF-1 and OPG has no significant difference between two groups.Conclution:the chang of growth characteristic of BMSCs of OVX goat maybe related to the deficiency of BMP. It maybe one of the mechanisms of osteoporosis. BMP could promote the differentiation of OVX BMSCs into osteoblast and express IGF-1 and OPG.