摘要
慢性炎症和脂质代谢紊乱是慢性肾病的重要特征,炎症因子影响肾脏细胞脂质代谢的作用机制尚不清楚,该研究旨在探讨炎症因子是否通过上调脂肪酸转运酶CD36的表达促进肾脏细胞脂肪酸摄取及脂质沉积。通过给予HMCs及HK2细胞肿瘤坏死因子(tumor necrosis factor-α,TNF-α)和白介素6(interleukin-6,IL-6)刺激处理24 h,应用qRT-PCR检测CD36的表达量,酶法检测HK2细胞内的甘油三酯(triglycercide,TG)水平。构建CD36过表达的细胞模型,使用荧光标记脂肪酸,观测细胞对外源性脂肪酸的摄取速率。然后利用小RNA干扰技术,构建CD36低表达的细胞模型,检测CD36低表达时细胞脂肪酸摄取速率及胞内甘油三酯、游离脂肪酸(free fatty acid,FFA)含量,葡萄糖调节蛋白78(GRP78)及内质网跨膜激酶(IRE1)的m RNA表达量。结果显示,炎性因子TNF-α和IL-6促进HMCs及HK2细胞TG的累积增加,并刺激细胞CD36的表达;CD36过表达促进HMCs及HK2细胞对FFA的摄取。当CD36表达被干扰后,炎性因子诱导的肾脏细胞TG及FFA的累积增加、FFA的摄取速率、细胞内GRP78、IRE-1的m RNA表达量及ROS含量均受到了抑制。该项研究表明,在HMCs及HK2细胞中,炎症因子可能通过促进CD36表达,导致细胞对FFA摄取增多,进而引起细胞脂质积聚;干预CD36能够改善炎性因子引起的脂质积聚、内质网应激以及细胞损伤,提示CD36可作为慢性肾脏疾病的潜在治疗靶点。
Chronic inflammation and lipid metabolism disorder are important features of chronic kidney disease.The mechanism of how inflammatory factors affect lipid metabolism in renal cells is not clear.This study aims to explore whether inflammatory factors promote fatty acid uptake and lipid deposition in renal cells by upregulating the expression of fatty acid transporter CD36.First,HMCs and HK2 cells were treated by TNF-α(tumor necrosis factor-α)and IL-6(interleukin-6)respectively for 24 h.TG(triglycerides)were detected by enzymatic detection.The mRNA expression level of CD36 was detected the by qRT-PCR.Next,CD36 overexpression cell model was established,fatty acids was fluorescent labeled to observe the uptake rate the of exogenous fatty acids.Then,small RNA interference technique was used to construct a cell model with low expression of CD36.Intracellular TG,intracellular FFA(free fatty acid),GRP78(glucose regulated protein 78)and IRE1(inosital-requiring enzyme 1)mRNA expression level were detected respectively.The results showed TNF-αand IL-6 promoted the accumulation of TG in HMCs and HK2 cells and stimulate the expression of CD36.Meanwhile,CD36 overexpression promoted FFA uptake in HMCs and HK2 cells.When CD36 expression was interfered,accumulation of TG and FFA,uptake rate of FFA and ERS(endoplasmic reticulum stress)induced by inflammatory cytokines were inhibited.In conclusion,inflammatory cytokines promotes CD36 expression in HMCs and HK2 cells,leading to increased uptake of FFA and lipid accumulation.Inhibition of CD36 expression may alleviate lipid accumulation and ERS induced by inflammatory cytokines.These results suggest that CD36 may be a potential therapeutic target for chronic renal disease.
作者
韦莉
吴婷婷
陈压西
杨萍
WEI Li;WU Tingting;CHEN Yaxi;YANG Ping(Key Laboratory of Metabolism on Lipid and Glucose,Center for Lipid Research,Chongqing Medical University,Chongqing 400016,China)
出处
《中国细胞生物学学报》
CAS
CSCD
2019年第10期1892-1900,共9页
Chinese Journal of Cell Biology
基金
中央引导地方科技发展专项(批准号:cstc2016zyydzx1002)资助的课题~~
