Adipophilin通过PI3K/Akt通路促进细胞内脂质蓄积

目的:探讨adipophilin促进细胞内脂质蓄积的可能机制,为动脉粥样硬化的防治提供参考。方法:分别通过q PCR、Western blot和油红O染色观察氧化型低密度脂蛋白(ox LDL)处理RAW264.7细胞不同时间后,细胞内Akt、p-Akt和adipophilin的蛋白水平及脂质蓄积情况;并检测PI3K/Akt抑制剂LY294002处理后,上述指标的变化;HEK293细胞过表达adipophilin后,检测Akt的活性;并用免疫共沉淀实验检测adipophilin与Akt之间的相互作用。结果:ox LDL处理细胞后,随着时间的延长,脂滴增多,Akt被活化,adipophilin表达增加,而LY294002处理则可抑制上述变化;过表达adipophilin后,p-Akt水平增高,但adipophilin与Akt之间未见直接相互作用。结论:Adipophilin可通过PI3K/Akt途径促进细胞内脂质蓄积,但可能不是通过直接相互关系发挥作用的。

Adipophilin promotes intracellular lipid accumulation through PI3K/Akt signaling pathway

AIM:To observe the possible mechanism through which adipophilin promotes the accumulation of intracellular lipids, and to provide a reference for controlling atherosclerosis.METHODS:RAW264.7 cells were incubated with oxidized low-density lipoprotein (oxLDL) for different time. qPCR, Western blot and Oil red O staining were used to observe the mRNA and protein levels of Akt, p-Akt and adipophilin and lipid accumulation. The above indexes were measured after the cells were treated with PI3K/Akt signaling pathway inhibitor LY294002. The activation of Akt was analyzed in the HEK293 cells over-expressing adipophilin. Co-immunoprecipitation was applied for analysis of protein-protein interaction between adipophilin and Akt. RESULTS:After incubation with oxLDL, the amount of lipid droplets, Akt activity and adipophilin expression increased in the cells with the extension of time (P<0.05). Moreover, LY294002 inhibited the above changes. The p-Akt levels increased after adipophilin over-expression. No direct interaction between adipophilin and Akt proteins was observed. CONCLUSION:Adipophilin promotes the accumulation of intracellular lipids through PI3K/Akt signaling pathway, but possibly not by direct interaction between adipophilin and Akt proteins.