摘要
目的：探讨大鼠骨髓间充质干细胞（MSCs）对单一周期的机械力刺激的反应以及Ets-1、Cbfa1和ALP的基因表达。方法：密度梯度离心法体外分离培养大鼠骨髓MSCs；应用四点弯曲加力系统对细胞施加40min、2000μe的机械牵张力，检测MSCs细胞增殖及ALP活性，并采用实时荧光定量RT-PCR检测Ets-1、Cbfa1和ALP的基因表达。结果：机械力刺激下，MSCs的增殖活力、ALP活性以及Ets-1、Cbfa1和ALP的基因表达均显著增高。Ets-1表达较早，加力后0．5h达到最高峰；而Cbfa1表达较晚，加力后6h达到最高峰；ALP的表达与Cbfa1相似。3个基因表达增高均在6—12h后恢复到正常水平。结论：单一周期的张应力可诱导Ets-1、Cbfa1和ALP在MSCs中呈时间依赖性表达，并促使MSCs短暂性骨向分化。机械力刺激是MSCs骨向分化的关键驱动因子．对牵张成骨骨痂形成具有重要的作用。
Objective：To study the response of MSCs to a single period of mechanical strain and expression patterns of Ets-1, Cbfal and ALP after the mechanical stretch. Methods：MSCs from bone marrow were isolated from SD rats and cultured in vitro. A four-point bending apparatus were used to perform a single period of mechanical strain （40 min, 2 000 μa） on MSCs to mimic a single activation of clinical distractor. Cell proliferation and ALP activity of MSCs were examined and the gene expression patterns of Ets-1, Cbfal and ALP were detected by SYBR Green quantitive real-time RT-PCR technique. Results：Cell proliferation, ALP activity and expression of Ets-1, Cbfal and ALP were all significantly up-regulated in stretched cells when compared with control group. Ets-1 increased immediately after mechanical loading and reached top expression level at 0.5 h. However, Cbfal increased later and got top expression at 6 h after mechanical loading. The expression pattern of ALP was similar to that of Cbfal. Transcription increases of the three genes all returned to control level within 6 to 12 h. Conclusion ：The mechanical strain can induce time-dependent expression increase of Ets-1, Cbfal and ALP which in turn drive transient osteogenic differentiation of MSCs. Mechanical stimulus is a key stimulator for osteogenic differentiation of MSCs and vital for bone formation in distraction osteogenesis
出处
《实用口腔医学杂志》
CAS
CSCD
北大核心
2008年第5期654-658,共5页
Journal of Practical Stomatology
基金
国家自然科学基金项目(编号:30371553)
