成骨细胞移植促进骨质疏松性骨折愈合的机制研究

Experimental study on machanism of osteoblasts grafts to accelerate fracture healing of osteoprosis rats

目的 用Y染色体追踪移植细胞在骨折愈合不同时相的存活、转归 ,及血管内皮生长因子 (VEGF)、转化生长因子 β1(TGF β1)的动态表达。 方法 将SD雄性乳鼠体外培养成骨细胞移植到 96只SD雌性鼠骨质疏松性骨折部位 (实验组 48只 ;对照组 48只 ) ,用原位杂交、免疫组织化学检测骨折愈合不同时相标本的Y染色体 ;以及VEGF、TGF β1和VEGFmRNA、TGF β1RNA的动态表达。结果 实验组大鼠 :成骨细胞移植后可在受体骨折部位局部生存、生长繁殖 ,促进骨质疏松性骨折愈合 ,移植 84d后仍存活。实验组大鼠 :VEGF、VEGF mRNA在 7d见阳性细胞 ,14d有分泌高峰。TGF β1mRNA在 3d见阳性细胞 ,7～ 10d有分泌高峰。对照组均未见明显分泌高峰。结论 移植的成骨细胞参与骨质疏松性骨折修复 ,至少存活 84d。VEGF、TGF β1的动态表达对促进骨折愈合起一定作用。

Objective To trace the long term survival of the grafted osteoblasts by Y chromosome and the activities of vascular endothelial growth factor (VEGF),transforming growth factor β1 (TGFβ1) duing fracture healing of osteoporosis rats.Methods The fracture models of osteoporosis rats were set up.The in vitro cultured osteoblasts from SD male mice were grafted to the osteoporosis-induced fracture sites of 96 SD female mice (experimental group and control group, n =48 each).Immunohistochemical method was used to detect the expression of VEGF,TGF β1 and in situ hybridization was applied to detect the expression of Y chromosome,VEGFmRNA,TGF β1mRNA.Results In experimental group,osteoblasts could survive,grow and proliferate in the fracture sites.The grafted osteoblasts were still alive on the 84th day after grafting.In experimental group,VEGF was detectable on the 7th day after osteoblast grafts,reaching its releasing peak on the 14th day.TGF β1 mRNA was detectable on the 3rd day post transplantation,reaching its releasing on the 7th to10th day post transplantation.However,there was not obviouisly releasing peaks in control group.Conclusion The grafted osteoblasts have a long term survival and enhance bone fracture healing of osteoporosis rats.VEGF and TGF β1 may play very important roles in accelerating fracture healing of osteoporosis rats.