胫骨牵引成骨过程中骨形态形成蛋白4及其受体的表达

背景:骨形态形成蛋白4及其受体在骨再生和修复过程中起着重要的作用,但具体机制尚不清楚.目的:建立小鼠胫骨牵引成骨模型,分析骨形态形成蛋白4及其受体在牵引成骨过程中的表达,探讨机械牵张力转化为生物信号从而调节骨再生过程的机制.方法:健康雄性8周龄CD-1小鼠36只,按照手术时间随机分成术后第5,9,13,17,24和31天组,每组6只.所有小鼠均接受左胫骨中上段低能截骨,安置体外延长固定架,截骨后5 d为静止期;截骨后第6天起开始每天进行胫骨延长,速率为0.2 mm,2次/d,共12 d,为牵引期;自第18天停止牵引,为固塑期.于术后第5,9,13,17,24和31天分别处死动物,采集胫骨标本,作组织学检查、RT-PCR和原位杂交实验分析骨形态形成蛋白4及其受体激活素样激酶3以及骨钙素的表达.结果与结论:组织学检查显示静止期修复过程基本与骨折愈合过程相似.小鼠骨折断端在持续牵引下有明显的骨痂形成,骨形态形成蛋白4及其受体激活素样激酶3以及骨钙素的mRNA的表达明显增强.结果表明,牵引成骨是一种持续的骨再生过程,机械张力可通过刺激骨形态形成蛋白4及其受体以及骨钙素的持续高表达维持骨痂的不断形成和再塑,以充填连续延长的骨折间隙.

Expression of bone morphogenetic protein 4 and its receptor in distraction osteogenesis of the tibia

BACKGROUND:Bone morphogenetic protein 4 (BMP-4) and its receptor play an important role in bone regeneration and repair process,but the mechanism is still unclear.OBJECTIVE:To understand how the mechanical forces are translated into biological signals that regulate bone regeneration and repair,we investigated the expression of BMP-4 and its receptor using a mouse tibia for distraction osteogenesis.METHODS:A total of 36 healthy male CD-1 mice of 8 weeks old,which were divided into six groups in the experimen...