胎球蛋白-a对3T3-L1脂肪细胞脂肪分解的影响

摘要

目的 观察胎球蛋白-a(fetuin-a)对脂肪分解的影响并探讨其可能的机制.方法 体外培养3T3-L1前脂肪细胞,分化成熟后用不同浓度的fetuin-a孵育.采用甘油检测试剂盒测定释放到上清液的甘油含量;采用Real-time PCR检测细胞中脂肪甘油三酯脂肪酶( Adipose triglyceride lipase,ATGL) 的mRNA表达;采用western blot检测细胞内磷酸化激素敏感脂肪酶(Hormone Sensitive Lipase,HSL)和ATGL的蛋白表达;采用ELISA试剂盒检测细胞内环磷酸腺苷(cyclic adenosine monophosphate,cAMP)的含量.结果 Fetuin-a能够抑制成熟脂肪细胞的脂肪分解,具有剂量依赖关系.Fetuin-a能够降低细胞内cAMP及磷酸化的HSL含量,同时使脂肪细胞ATGL mRNA水平及蛋白表达降低.结论 Fetuin-a抑制3T3-L1脂肪细胞的脂肪分解,其机制可能是通过抑制cAMP-PKA-HSL通路以及降低细胞内ATGL的表达而发挥作用的.%Objective To observe the effect of fetuin a on lipolysis of 3T3 LI adipocytes and to explore its regula tion mechanism. Methods 3T3 L1 preadipocytes were induced under standard differentiation process and treated with different concentration of fetuin a for 12h after differentiating. Lipolysis of adipocytes was examined by the measure ment of glycerol release;The expressions of mRNA of ATGL were analysed using Real time PCR;The expressions of protein of phospho HSL、ATGL were analysed using western blot. cAMP levels in cell extracts were measured using a ELISA kit. Results Fetuin a inhibited basal lipolysis in adipocytes in a dose dependent manner. Fetuin a decreased in tracellular cAMP production and the expression of phospho HSL protein. Fetuin a also decreased the expressions of ATGL mRNA and protein. Conclusion These results suggested that fetuin a inhibited lipolysis of adipocyte through inactivation of signaling cascades mediated by cAMP PKA HSL and ATGL.