SREBP1c-ACCα/FAS和SREBP1c-FABP3轴向调控HepG2胞内脂质合成与转运  

SREBP1c-ACCα/FAS and SREBP1c-FABP3 axially regulate intracellular lipid synthesis and transport in HepG2

作　　者：付常振 郑颖 路遥[1] 王仁军[1,2] 刘庆平 FU Changzhen;ZHENG Ying;LU Yao;WANG Renjun;LIU Qingping(College of Life Science and Technology,Dalian University,Dalian 116600,China;Key Laboratory of Glucolipid Metabolism in Liaoning Province,Dalian 116600,China)

机构地区：[1]大连大学生命科学与技术学院,大连116600 [2]辽宁省糖脂代谢研究重点实验室,大连116600

出　　处：《生物学杂志》2023年第2期9-13,26,共6页Journal of Biology

基　　金：大连市青年科技之星项目(2019RQ148);国家自然科学基金项目(No.81673494)。

摘　　要：SREBP1c是长链脂肪酸(LCFAs)从头合成及胞内转运的关键调控因子,探讨SREBP1c-ACCα/FAS和SREBP1c-FABPs轴向调控LCFAs合成与转运紊乱诱发NAFLD的分子机制。制备介导SREBP1c过表达腺病毒Ad-SREBP1c,侵染HepG2细胞后酶法测定胞内TG含量,RT-PCR及Western Blot法检测ACCα、FAS、FABP3和FABP4的表达量。结果显示:Ad-SREBP1c病毒滴度为1.6×10^(9)GFU/mL;侵染HepG2细胞24 h后介导SREBP1c mRNA及蛋白的表达量分别升高89.73倍和7.27倍(P<0.01),促进下游LCFAs合成基因ACCα和FAS分别升高1.55倍和3.42倍(P<0.01),蛋白表达量分别升高1.23倍(P<0.05)和1.43倍(P<0.01);FABP3 mRNA和蛋白表达量分别升高4.03和2.06倍(P<0.01),FABP4无显著变化;Ad-SREBP1c侵染HepG2细胞24 h和48 h胞内TG含量分别升高1.24倍(P<0.05)和2.41倍(P<0.01);SREBP1c-ACCα/FAS轴向调控LCFAs从头合成及SREBP1c-FABP3轴向介导胞内转运,可能是促使胞脂异位沉积导致NAFLD发生的关键机制之一。SREBP1c is a key regulator of de novo synthesis and intracellular transport of long-chain fatty acids(LCFAs).In this study,the potential relationship between disruption of the synthesis/transport of LCFAs and non-alcoholic fatty liver disease(NAFLD),which was axially regulated by SREBP1c-ACCα/FAS and SREBP1c-FABPs,was investigated.The adenovirusAd-SREBP1c was prepared for mediating the overexpression of SREBP1c,and the intracellular triglyceride(TG)content was measured by enzymatic assay followed by transfection of HepG2 cells with Ad-SREBP1c.The transcription and translation levels of ACCα,FAS,FABP3 and FABP4 were measured by RT-PCR and Western blot respectively.Ad-SREBP1c virus titer was 1.6×10^(9)GFU/mL.The transcription and translation levels of SREBP1 were enhanced by 89.73-fold(P<0.01)and 7.27-fold(P<0.01),respectively,24 h after transfection in HepG2 cells mediated by Ad-SREBP1.The mRNA levels of ACCαand FAS for downstream LCFAs synthesis were increased by 1.55-fold(P<0.01)and 3.42-fold(P<0.01),respectively,and with increasement each by 1.23-fold(P<0.05)and 1.43-fold(P<0.01)in protein expression levels.The FABP3 mRNA and protein levels were elevated by 4.03-fold(P<0.01)and 2.06-fold(P<0.01)respectively,while no significant change was observed in FABP4.Meanwhile,intracellular TG contents of HepG2 cells of 24 h and 48 h after transfection by Ad-SREBP1c were increased by 1.24-fold(P<0.05)and 2.41-fold(P<0.01),respectively.SREBP1c-ACCα/FAS could axially regulate the de novo synthesis of LCFAs,and SREBP1c-FABP3 could axially mediate the intracellular transport of LCFAs at the same time,which was probably the key mechanism contributing to the development of NAFLD due to cytosolic ectopic lipid deposition.

关 键 词：非酒精性脂肪性肝病 固醇调节元件结合蛋白1C 乙酰辅酶A羧化酶α/脂肪酸合成酶 脂肪酸结合蛋白3 

分 类 号：Q7[生物学—分子生物学]