Rab18通过PPARγ下调PLIN2以减少巨噬细胞脂质蓄积  

Rab18 down-regulates PLIN2 through PPARγto reduce lipid accumulation in macrophages

作　　者：张荣 李晓歌 陈雁斌[2] 蒋思怦 杨丽[1] 袁中华[1] ZHANG Rong;LI Xiao-ge;CHEN Yan-bin;JIANG Si-peng;YANG Li;YUAN Zhong-hua(Institute of Cardiovascular Diseases,University of South China,Key Laboratory for Arteriosclerology of Hunan Province,Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Diseases,Hengyang 421001,China;Affiliated Hospital of Xiangnan College,Chenzhou 423000,China)

机构地区：[1]南华大学心血管疾病研究所,动脉硬化学湖南省重点实验室,湖南省动脉硬化性疾病国际科技创新合作基地,湖南衡阳421001 [2]湘南学院附属医院,湖南郴州423000

出　　处：《中国病理生理杂志》2021年第8期1367-1375,共9页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.81973326);湖南省教育厅资助项目(No.17C1476);郴州市科技局资助项目(No.CZKJ2016028)。

摘　　要：目的:探讨Rab18是否通过过氧化物酶体增殖物激活受体γ(PPARγ)下调脂滴包被蛋白2(PLIN2)以减少巨噬细胞脂质蓄积。方法:用氧化型低密度脂蛋白(ox-LDL)处理THP-1巨噬细胞,通过Westernblot法检测ox-LDL作用不同时间(0 h、6 h、12 h和24 h)后细胞内Rab18、PPARγ及PLIN2的表达情况,并使用油红O染色法观察细胞内脂质蓄积的变化。制备表达野生型、高活型和低活型Rab18的巨噬细胞,分别加入ox-LDL处理,用Westernblot及细胞免疫荧光染色法检测细胞内PPARγ和PLIN2的表达量,并采用油红O染色法观察细胞内脂质蓄积情况。分别用PPARγ激动剂GW1929和抑制剂T0070907预处理表达高活型Rab18的巨噬细胞,再用ox-LDL孵育该细胞,Westernblot及免疫荧光染色法分别检测巨噬细胞内PPARγ和PLIN2的表达量及PPARγ的核转位情况,同时采用油红O染色法观察细胞内脂质蓄积情况。结果:ox-LDL处理24 h后,THP-1巨噬细胞Rab18、PPARγ和PLIN2的表达水平显著增加,脂质蓄积增加(P<0.05)。ox-LDL处理后,表达野生型和高活型Rab18的巨噬细胞中PPARγ及PLIN2表达下调,脂质蓄积减少(P<0.05),而表达低活型Rab18的巨噬细胞上述指标则无明显变化。Rab18能抑制PPARγ的激活,并抑制其核转位。表达高活型Rab18的巨噬细胞中PLIN2表达下调能被PPARγ激动剂GW1929逆转,并使脂质蓄积增多。PPARγ抑制剂处理后,表达高活型Rab18的巨噬细胞中PLIN2表达及脂质蓄积进一步减少。结论:Rab18通过抑制PPARγ的激活下调PLIN2表达进而抑制巨噬细胞脂质蓄积。AIM:To explore whether the Rab GTPase Rab18 down-regulates adipose differentiation-related protein perilipin 2(PLIN2)through peroxisome proliferator-activated receptorγ(PPARγ)to reduce lipid accumulation in macrophages.METHODS:THP-1 macrophages were co-incubated with oxidized low-density lipoprotein(ox-LDL).At different time points(0,6,12 and 24 h),Western blot was used to detect the protein expression of Rab18,PPARγand PLIN2 in the cells,and the oil red O staining method was used to observe the intracellular lipid accumulation.The macrophages expressing wild-type(WT),high-activity(HA)and low-activity(LA)Rab18 were prepared and incubated with ox-LDL,Western blot and cellular immunofluorescence were used to detect the changes of intracellular PPARγand PLIN2,and oil red O staining method was used to observe lipid accumulation in the cells.The macrophages expressing HA Rab18 were pretreated with PPARγagonist GW1929 or inhibitor T0070907,and then treated with ox-LDL.Western blot and cellular immunofluorescence were used to detect the changes of PPARγand PLIN2 in the macrophages,and the oil red O staining method was used to observe the intracellular lipid accumulation.RESULTS:The expression levels of Rab18,PPARγand PLIN2,as well as lipid accumulation were increased significantly after ox-LDL treatment for 24 h(P<0.05).The expression of PPARγand PLIN2,as well as lipid accumulation were decreased in the macrophages expressing WT and HA Rab18 after ox-LDL treatment(P<0.05),while the above indexes in the macrophages expressing LA Rab18 did not change significantly.Over-expression of Rab18 down-regulated the expression of PPARγ,and inhibited its nuclear translocation.The down-regulation of PLIN2 expression in the macrophages expressing HA Rab18 can be reversed by PPARγagonist GW1929,resulting in the increase in lipid accumulation,while PPARγinhibitor T0070907 exerted the opposite effect.CONCLUSION:Rab18 down-regulates the expression of PLIN2 through PPARγand inhibits lipid accumulation in macrophages.

关 键 词：Rab18蛋白 脂滴包被蛋白2 过氧化物酶增殖物激活受体Γ 巨噬细胞 动脉粥样硬化 

分 类 号：R363.2[医药卫生—病理学] R543.5[医药卫生—基础医学]