生物学杂志

生物学杂志 ›› 2023, Vol. 40 ›› Issue (2): 9-.doi: 10.3969/j.issn.2095-1736.2023.02.009

• 研究报告 • 上一篇    下一篇

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

付常振1,2， 郑　颖1， 路　遥1， 王仁军1,2， 刘庆平1,2   

  1. 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
  • 出版日期:2023-04-18 发布日期:2023-04-18
  • 通讯作者: 刘庆平，教授，博士生导师，研究方向为代谢性疾病药物药理，E-mail:qingpingliu40@126.com
  • 作者简介:付常振，博士，讲师，研究方向为脂代谢生物学，E-mail: fcz200801@163.com； 郑颖，硕士研究生，研究方向为生物化学与分子生物学，E-mail: 809219446@qq.com；付常振和郑颖为并列第一作者
  • 基金资助:
    大连市青年科技之星项目（2019RQ148）； 国家自然科学基金项目（No.81673494）

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

FU Changzhen1,2, ZHENG Ying1, LU Yao1, WANG Renjun1,2, LIU Qingping1,2   

  1. 1. College of Life Science and Technology, Dalian University, Dalian 116600, China;
    2. Key Laboratory of Glucolipid Metabolism in Liaoning Province, Dalian 116600, China
  • Online:2023-04-18 Published:2023-04-18

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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1.6×109GFU/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。

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

Abstract: 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 1.6×109GFU/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 ACCα and 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.

Key words: non-alcoholic fatty liver disease (NAFLD), sterol regulatory element binding protein 1c (SREBP1c), ACCα/FAS, FABP3

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