BMP-2、bFGF在牵引成骨中的表达及意义

The Expression and Biologic Effect of BMP-2 and bFGF during Mandibular Distraction Osteogenesis

目的 :通过两种不同术式的比较 ,研究骨形态发生蛋白 - 2 (BMP - 2 )、碱性成纤维细胞生长因子 (bFGF)的表达水平和成骨的关系 ,探讨牵引成骨的成骨机制。方法 :2 8只狗随机分为牵引成骨组和直接延长组各 12只及正常对照组 4只 ,用免疫组化染色方法观察比较BMP - 2、bFGF在两组牵引第 6天、固定 2周、固定 8周时的表达情况。结果 :两组在牵引第 6天骨断端附近的新生编织骨边缘基质及周缘的活跃的成骨细胞、骨膜下及牵开区增生活跃的间充质细胞、成纤维细胞、胶原纤维基质均可见BMP - 2、bFGF强阳性的染色 ,染色平均灰度比较均无统计学差异 (P >0 .0 5 ) ;牵引后固定 2周 ,牵引组新生编织骨边缘的成骨细胞、软骨细胞、牵开区纤维结缔组织仍可见BMP - 2、bFGF阳性染色 ,而直接延长组的BMP - 2、bFGF在牵开区的染色强度明显降低 (P <0 .0 5 ) ;牵引后固定8周 ,BMP - 2、bFGF在牵引组和直接延长组的组织中的染色强度均明显减弱 ,染色灰度比较均无统计学差异 (P >0 .0 5 )。结论 :在下颌骨牵引成骨过程中 ,在机械的牵引力和微创伤等多种因素刺激下 ,局部牵开区BMP - 2和bFGF持续高表达。两种生长因子可能共同参与促进了牵开区大量新骨的形成。

Objective: To probe the mechanism of expression and effect of Bone Morphogenetic Protein2 (BMP-2) and basic fibroblast growth factor (bFGF) which result in successful osteogenesis. Methods: Twenty-eight adult dogs were randomly divided into DO group (n=12) ,acute lengthening group(n=12) and normal group(n=4). 4 animals were respectively sacrificed in the 6th day of distraction, 2, 8 weeks after completion of distraction. Callus and the same regions of normal mandible were harvested. The expression of BMP-2 and bFGF were investigated by means of immunohistochemistry.Results: In DO group and acute lengthening group, during the distraction period, the strongly positive stain of BMP-2 and bFGF were both found in the osteoblasts around the newly formed trabecular bone and the bone formation front, mesenchymal cells and fibroblasts from the periosteum and distraction gap and the fibrous collagen. There were no statistic difference between the stain grays of two groups; after 2 weeks of consolidation. There were significant decreasing expression of BMP-2 and bFGF in callus of acute lengthening group comparing to DO group (P<0.05); after 8 weeks of consolidation, the stain intensity of BMP-2 and bFGF in the two groups were both markedly decreased(P>0.05). Conclusion: During the distraction osteogenesis, the distraction force and other factors such as micro-trauma may stimulate the production of BMP-2 and bFGF in local distraction gap. BMP-2 and bFGF may both participate in the effects of promoting the plenty osteogenesis.