骨不连微环境中骨形态发生蛋白-9与表皮生长因子受体表达变化的初步研究

A preliminary study of the expression of bone morphogenetic protein 9 and epidermal growth factor receptor in the nonunion microenvironment

摘要:

目的：研究骨不连微环境下局部组织中骨形态发生蛋白-9（bone morphogenetic protein-9，BMP9）与表皮生长因子受体（epidermal growth factor receptor，EGFR）的表达及成骨细胞与破骨细胞数量的变化，为骨不连的病因与治疗提供依据。方法：选取12只健康的3月龄新西兰大白兔为实验组构建骨不连动物模型，同时选取6只同龄同种健康兔为对照组，以X射线检查验证造模是否成功，以Western blot、免疫组织化学检测局部组织中BMP9与EGFR表达量的变化，以苏木素-伊红（hematoxylin- eosin，HE）染色、抗酒石酸酸性磷酸酶（tartaric acid resistance，TRAP）染色观察局部组织中成骨细胞与破骨细胞数量。结果：X射线检查结果提示骨不连动物模型构建成功，Western blot和免疫组织化学结果提示骨折愈合后期BMP9与EGFR表达量较骨折愈合早期明显降低，且骨不连微环境中BMP9表达量较对照组明显降低，但EGFR表达量较对照组差异不明显；HE染色和TRAP染色结果提示骨折愈合后期成骨细胞数量较骨折愈合早期明显减少，且骨不连微环境中成骨细胞数量较对照组减少更明显，但实验组与对照组破骨细胞数量在骨折早期、后期均无明显差异。结论：骨不连可能与局部组织中BMP9、EGFR表达量降低及成骨细胞的数量减少有关。

Abstract:

Objective：To investigate the expression of bone morphogenetic protein 9（BMP9） and epidermal growth factor receptor （EGFR） and the number of osteoblasts and osteoclasts in local tissues in the nonunion microenvironment，and to provide a basis for the etiology and treatment of nonunion. Methods：Twelve 3-month-old healthy New Zealand white rabbits were selected as exper－imental group to develop an animal model of nonunion and six healthy New Zealand white rabbits of the same age were selected as control group. X-ray examination was used to verify the success of modeling. Western blot and immunohistochemistry were used to determine the expression of BMP9 and EGFR in local tissues. Hematoxylin-eosin（HE） staining and tartrate-resistant acid phos－phatase（TRAP） staining were used to count osteoblasts and osteoclasts. Results：X-ray examination indicated that the animal model of nonunion was successfully developed. Western blot and immunohistochemistry showed that the expression of BMP9 and EGFR was significantly reduced from the early stage to the late stage of fracture healing；the expression of BMP9 in the nonunion microen－vironment was significantly lower than that of the control group，while the expression of EGFR was not significantly different from that of the control group. HE staining and TRAP staining showed that the number of osteoblasts was significantly reduced from the early stage to the late stage of fracture healing，and the decrease in osteoblasts in the nonunion microenvironment was greater than that in the control group；however，there was no significant difference in the number of osteoclasts between the experimental group and the control group in both early and late stages of fracture healing. Conclusion：The development of bone nonunion may be associ－ated with decreased expression of BMP9 and EGFR and number of osteoblasts in local tissues.