骨髓间充质干细胞对机械张应力刺激的反应及转化生长因子-β和胰岛素样生长因子-Ⅱ的基因表达  

Response of bone marrow mesenchymal stem cells to mechanical stretch and gene expression of transforming growth factor-β and insulin-like growth factor-Ⅱ under mechanical strain

作　　者：韩立赤[1] 戚孟春[2] 孙红[2] 胡静[3] 邹淑娟[4] 李继华[3] 

机构地区：[1]大连大学医学院口腔系,辽宁大连116622 [2]华北煤炭医学院口腔系,河北唐山063000 [3]四川大学华西口腔医学院口腔颌面外科学教研室,四川成都610041 [4]四川大学华西口腔医学院正畸学教研室,四川成都610041

出　　处：《华西口腔医学杂志》2009年第4期381-385,共5页West China Journal of Stomatology

基　　金：国家自然科学基金资助项目(30772454);四川省科技厅攻关课题资助项目(2006Z09-013)

摘　　要：目的探讨大鼠骨髓间充质干细胞(MSCs)对机械张应力刺激的反应及力学刺激下转化生长因子-β(TGF-β)和胰岛素样生长因子-Ⅱ(IGF-Ⅱ)基因表达的规律。方法分离培养大鼠骨髓MSCs,应用四点弯曲加力系统对细胞施加单一周期的机械张应力刺激(2000με,40min)。检测MSCs细胞增殖及碱性磷酸酶(ALP)活性,并采用实时荧光定量RT-PCR检测TGF-β和IGF-Ⅱ的基因表达。结果机械张应力刺激下,MSCs的增殖活力、ALP活性以及TGF-β和IGF-Ⅱ的基因表达均显著增高。TGF-β和IGF-Ⅱ的mRNA水平在加力后瞬时达最高水平;与对照细胞比较,分别增加了51.44和8.92倍。除加力后6h有少许增高外,TGF-β和IGF-Ⅱ的表达随时间逐步下降,并于加力后12h恢复到对照组水平。结论机械张应力刺激可促进MSCs增殖,提高其ALP活性,使TGF-β和IGF-Ⅱ基因表达呈时间依赖性上调,并最终诱导MSCs向成骨细胞分化。机械力学刺激是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 rat bone marrow mesenchymal stem cells （MSCs） to a single period of mechanical strain and expression patterns of transforming growth factor-β （TGF-β） and insulin-like growth factor- Ⅱ （IGF-Ⅱ ） after mechanical stretch. Methods Bone marrow MSCs were isolated from SD rats and cultured in vitro. A four-point bending apparatus were used to perform a single period of mechanical strain （2 000 με, 40 min） on MSCs. Cellular proliferation and alkaline phosphatase （ALP） activity of MSCs were examined and gene expression patterns of TGF-β and IGF-Ⅱ were detected by SYBR green quantitative real-time RT-PCR. Results Cell proliferation, ALP activity and expression of TGF-β and IGF-Ⅱ were all significantly up-regulated in stretched MSCs when compared with their controls. The mRNA levels of TGF-β and IGF-Ⅱ got top increase immediately after mechanical loading and increased about 51.44 and 8.92 folds, respectively, when compared with control cells. Expression of TGF-β and IGF-Ⅱ decreased with time and returned to control level at 12 h after mechanical stimulus, despite of a small increase at 6 h. Conclusion The mechanical stretch can promote MSCs proliferation, up-regulate its ALP activity and induce a time-dependent expression increase of TGF-β and IGF-Ⅱ which in turn result in osteogenic differentiation of MSCs. Mechanical stimulus is a key stimulator for osteogenic differentiation of MSCs and vital for bone formation in distraction osteogenesis.

关 键 词：间充质干细胞 机械牵张 转化生长因子-Β 胰岛素样生长因子-Ⅱ 

分 类 号：R78[医药卫生—口腔医学]