摘要
目的 探究骨折早期力学环境对大鼠骨折端间充质干细胞(MSCs)成骨及成软骨分化的影响。方法 建立大鼠股骨骨折模型,以不同刚度系数的外固定架予以固定,分为对照组、高刚度外固定架组和低刚度外固定架组。术后当天和2周拍摄X线片,术后6周取患侧股骨,予以组织病理学检查。于术后2、6、10、14d取骨痂组织,RT-q PCR检测Runx2、Osterix(OSX)及Sox9转录表达水平,Western blot检测Runx2、Sox9蛋白的表达。结果 X线检查显示,术后2周,低刚度组骨痂量明显多于高刚度组;组织学检查显示,术后6周,对照组、高刚度组骨痂较少,有大量活跃的骨细胞,低刚度组骨折端软骨链接,在与正常骨组织接触处形成了软骨成骨的骨痂组织。RT-qP CR结果显示,随着时间增加,三组Runx2、OSX mRNA表达水平均有增加趋势。Sox9 mRNA表达水平,对照组和高刚度组10d内呈增加趋势,14d时有所下降,低刚度组则14d内一直增加。同一时间点Runx2、OSX及Sox9的表达水平均表现为低刚度组>高刚度组>对照组(P<0.05);Western blot结果与RT-qP CR结果相一致。结论 力学环境会影响骨折区MSCs成骨及成软骨分化,微动可促进骨折愈合。
Aim To explore the influence of mechanical environment on differentiation of mesenchymal stem cells（MSCs） at fracture site during early stage of fracture healing. Methods The rat femur fracture models were established and fixed with external fixation frame of different stiffness coefficient and were divided into three groups,namely,the sham group with super-high stiffness external fixation frame,the high stiffness fixation frame group and the low stiffness fixation frame group. The bone callus and the degree of fracture healing after two weeks compared with the very day after surgery were observed by X-ray. And the effects were evaluated respectively by histopathology 6 weeks after operation. Callus tissues of 2 days,6 days,10 days,14 days after operation were acquired. Runx2,Osterix and Sox9 expression were measured by RT-q PCR.Runx2 and Sox9 were tested by Western blot. Results X-ray showed that the amount of callus of high stiffness group was significantly less than that of low stiffness group. Histological study showed, sham group and high stiffness group achieved less callus and had lots of active bone cells while low stiffness group got cartilage ossification well. The results of RT-q PCR showed that the level of Runx2,Osterix increased within 14 days. And Sox9 reached the highest level in sham group and high stiffness group 10 days after surgery and declined in 14 days while low stiffness group had been rising within 14 days after surgery. The expression levels of Runx2,OSX and Sox9 in 14 days after operation presented statistically significant difference among the three groups at the same time point,i.e. low stiffness group high stiffness group the sham group（P 0. 05）. The results of Western blot were consistent with those of RT-q PCR. Conclusion The differentiation of MSCs at fracture site is affected by the mechanical environment,and subtle movement could promote the healing of fracture sites.
作者
李颖
黎立
李俊玲
张俊忠
王世立
LI Ying;LI Li;LI Jun-ling;ZHANG Jun-zhong;WANG Shi-li(Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan 250011, China;Tianjin Anding Hospital, Tianjin 300222;School of Medical and Life Science,University of Jinan and Shandong Academy of Medical Science, Jinan 250022, China;Medical Biotechnology Center,Shandong Academy of Medical Sciences, Jinan 250062,China)
出处
《中国药理学通报》
CAS
CSCD
北大核心
2018年第6期803-809,共7页
Chinese Pharmacological Bulletin
基金
国家自然科学基金资助项目(No 81373661)
山东省科技发展计划项目(No 2013G0021806)
关键词
力学环境
骨折愈合
干细胞
分化
Runx2
OSX
SOX9
mechanical environment
fracture healing
mesenchymal stem cells
differentiation
Runx2
OSX
Sox9
