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目的 探讨高重力对前成骨细胞MC3T3-E1形态和成骨功能的影响.方法 将MC3T3-E1细胞按不同高重力分为对照组、5 g组、10 g组、15 g组、20 g组,实验组每次加载30 min连续加载3d,对照组同步置于除g值外相同的环境中.鬼笔环肽染色考察细胞骨架蛋白形态;碱性磷酸酶(alkaline phosphatase,ALP)活性检测试剂盒检测ALP含量;实时定量PCR检测ALP、Ⅰ型胶原(collagen Ⅰ,Col Ⅰ)、骨钙素(osteocalcin,OC)、runt相关转录因子(runt-related transcription factors,Runx2)的基因表达;Western blotting检测Col Ⅰ、OC蛋白表达.结果 高重力条件下成骨细胞胞体变薄,细胞表面积明显增大;细胞骨架排列结构变得疏松、松散,微丝肌动蛋白束状结构减少,微丝呈弥散状,有序性降低.成骨分化相关指标ALP、Col Ⅰ、OC、Runx2的基因均显著上调;Col Ⅰ和OC蛋白亦呈现高表达.对照组茜素红染色只有极少量面积很小的桔红色结节,高重力加载后各组细胞明显形成面积大小不一的桔红色结节.结论 高重力下成骨细胞可通过骨架结构发生重排引起细胞形态的改变,并进一步通过上调分化相关基因和蛋白表达,有效刺激成骨细胞成熟分化.“,”Objective To explore the effect of hypergravity on morphology and osteogenesis function of preosteoblast MC3T3-E1 ceils.Methods The cultured MC3T3-E1 cells under hypergravity by different loading forces were divided into five groups,including control group,5 g group,10 g group,15 g group and 20 g group.The experimental groups were loaded for 30 min each time in 3 successive days,and the control group with no g-value was synchronously exposed to the same surrounding.The morphology of cytoskeletal protein was observed by phalIoidin staining,The alkaline phosphatase (ALP) content was examined by ALP activity assay kit,the gene expression of ALP,collagen Ⅰ (Col Ⅰ),osteocalcin (OC),runt-related transcription factors (Runx2) was measured by real-time quantitative PCR,and the protein expression of Col Ⅰ and OC was tested by Western blotting.Results Under the condition of hypergravity,cell body of osteoblast became thinner,but its surface area increased significantly;with the structure of skeletal arrangement becoming loose,actin microfilament structure reduced so that the orderly arrangement of actin-like dispersion lowered.The gene expressions of related indicators of osteogenic differentiation including ALP,Col][,OC,Runx2 were significantly up-regulated,which was the same as Col Ⅰ protein and OC protein after hypergravity loading.A very minute quantity of small red-orange nodules was found in the control group,while the cells in experimental groups after hypergravity loading obviously formed various sizes of red-orange nodules.Conclusions Under hypergravity,changes in osteoblast morphology can be triggered by rearrangements of skeletal structure.Furthermore,osteoblast maturation and differentiation can be stimulated effectively by up-regulating differentiation-related gene and protein expressions.