中文摘要：

目的探讨整合素β1对泡沫细胞形成的影响并初步阐明其作用机制。方法针对整合素B1基因设计并化学合成siRNA。RAW264．7细胞与含0．1g／LOX—LDL的培养基培养，分为空白对照组、转染siRNA阴性对照组（siRNANC）和siRNA组。应用油红O染色观察泡沫细胞形成，胆固醇氧化酶终点法测定细胞内总胆固醇的含量，原子力显微镜观察细胞膜上小凹结构的变化，Westernblot和实时荧光定量PCR检测清道夫受体CD36蛋白和mRNA的表达。结果与空白对照组相比，siRNA组油红0染色阳性细胞数明显减少，细胞内总胆固醇／总蛋白显著降低（P〈0．01）。原子力显微镜下，siRNA干扰整合素B1基因后细胞未见明显的小凹结构。Westernblot及荧光定量PCR结果显示siRNA组CD56蛋白和mRNA表达均显著减少（P〈0．01）。结论沉默整合素β1基因能有效减少RAW264．7细胞对OX—LDL的摄取，抑制泡沫细胞的形成，其机制可能与降低清道夫受体CD36的表达和减少细胞膜表面的小凹相关。

英文摘要：

Aim To investigate the effect of integrin β1 on foam cells formation by RNA interference （RNAi） - mediated silencing. Methods Short hairpin RNAs against mouse integrin β1 was constructed. The foam cell formation induced by oxidized low density lipoprotein （ox-LDL） was analyzed in mouse RAW264. 7 cells which were divided into three groups,including control group, siRNANC group （ with transfection of siRNA negative） and siRNA group. Formation of foam cells and contents of total cholesterol were detected, atomic force microscope was used to observe the caveolaes on cell membrane,expression of CD36 protein and mRNA were detected. Results Decreased integrin 131 expression led to reduce foam cell formation and contents of total cholesterol in cells. Meanwhile, there were no caveolaes on cell membrane and expression of CD36 protein and mRNA were both decreased. Conclusions Silencing of integrin β1 reduces foam cells formation. Integrin 131 modulated the capacity of macrophages to take up ox-LDL possibly via CD36-dependent pathway.