中文摘要：

目的：探讨模拟微重力对人牙髓干细胞（human dental pulp stem cells,HDPSCs）微丝及迁移能力的影响。方法：利用旋转培养系统（rotary cell culture system,RCCS）将HDPSCs分为常规对照组和微重力培养组,分别于4、12、24、48、72h行免疫荧光染色,观察微丝的变化;72h后,透射电镜观察微丝骨架变化及细胞迁移实验检测细胞迁移能力。结果：4h时即有粗大的微丝纤维束解聚,24～72h变得模糊,紊乱,且出现多向排列趋势;实验组细胞迁移数量少于对照组（P〈0.05）。结论：人牙髓干细胞微丝在模拟微重力环境下发生改变,呈时间依赖性并使细胞迁移能力降低。

英文摘要：

Objective： To observe and study the influence of simulated microgravity on the microfilament and the ability of human pulp stem cells to migrate.Methods： Human pulp stem cells were divided into control group and microgravity group with rotary cell culture system.At 4h,12h,24h,48h and 72h of cell culture,immunofluorescence staining was performed to observe the structure of microfilament.The structure of microfilament was also observed using transmission electron microscope（TEM） after 72h cultivation.Migration assay was carried out to detect the ability of human pulp stem cells to migrate.Results： After 4h cultivation,The structure of microfilament was altered;the depolymerization of microfilament with irregular and multidirection arrangement was observed from 24h to 72h;The number of cell migration in experimental group was decreased compared with the control group（P〈0.05）.Conclusion： The structure of microfilament cytoskeleton in human pulp stem cells can be altered in a time-dependent manner under simulated microgravity environment,which leads to a reduction in the ability of cells to migrate.