张成俊;夏亚一;王常德;汪静;汉华;王翠芳;

• 1:兰州大学第二医院骨科研究所

摘要(Abstract)：

[目的]探讨流体切应力(FSS)促成骨细胞增殖、分化作用与细胞周期从G1期向S期转化机制的关系,为确立最佳生理应力刺激骨再生提供依据。[方法]从KM乳鼠颅盖骨提取原代成骨细胞,在体外流体小室内分别受FSS(12dyn/cm2)作用0、0.25、0.5、1、2、4h,通过MTT法分析细胞增殖能力,并利用碱性磷酸酶(ALP)的表达评价其分化能力;通过流式细胞仪、免疫荧光染色和RT-PCR测定细胞周期G1/S百分比、细胞周期依赖激酶2和4(CDK2、CDK4)的活性改变及E2F1、p27mRNA的表达实现FSS促成骨细胞由G1期转向S期的测定。[结果]FSS促增殖作用在短期(0.25h、0.5h)明显,并且细胞生长曲线前移;但在1、2、4h却有明显抑制增殖作用。FSS同样增加了ALP的活性,尤其在应力作用0.25、0.5h时显著(比对照达128%和158%);而应力作用1、2、4h后减低了ALP的表达。在FSS作用1h内细胞周期S期百分比增高,作用0.5h后与对照组比较明显增高(P<0.05);但随着时间的增加细胞周期S期百分比开始下降,当作用时间持续4h后S期百分比下降明显(P<0.05)。流体切应力增加了活化pRb的CDK2、CDK4的活性,而且与CDK2相关的E2F1表达量也明显增加;而细胞周期依赖激酶抑制剂p27在流体切应力作用下有所下降。其中流体切应力在0.25h、0.5h明显增加了E2FlmRNA的表达水平(P<0.05),此效应在作用1h后减退。[结论]适宜的流体切应力通过上调CDK2、CDK4及E2F1,下调p27,使细胞从G1期转化到S期,在流体切应力促成骨细胞增殖、分化机制中起重要作用;并且这种作用有明显的FSS作用时间限制性。

关键词(KeyWords)： 成骨细胞;流体切应力;增殖;分化;细胞周期;G1/S调控点

Abstract:

Keywords:

基金项目(Foundation):

作者(Author): 张成俊;夏亚一;王常德;汪静;汉华;王翠芳;

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参考文献(References)：

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