天津医药 ›› 2020, Vol. 48 ›› Issue (10): 936-941.doi: 10.11958/20193626

• 细胞与分子生物学 • 上一篇    下一篇

厄贝沙坦激活PPAR-γ介导AMPK/mTOR通路诱导自噬改善LO2细胞脂肪变

钟娟1,雷任国2,钟庆荣1,覃亚勤2,黎洪棉1△   

  1. 1南宁市第一人民医院中医科(邮编530022);2南宁市第四人民医院
  • 收稿日期:2019-12-04 修回日期:2020-06-24 出版日期:2020-10-15 发布日期:2020-10-30
  • 通讯作者: 钟娟 E-mail:zjanny919@163.com
  • 基金资助:
    南宁市科学研究与技术开发计划项目(20183040-1)

Irbesartan alleviates steatosis in LO2 cells by promoting autophagy via PPAR- γ mediated AMPK/mTOR pathway

ZHONG Juan1, LEI Ren-guo2, ZHONG Qing-rong1, QIN Ya-qin2, LI Hong-mian1△   

  1. 1 Department of Traditional Chinese Medicine, the First People’s Hospital of Nanning, Nanning 530022, China; 
    2 the Fourth People’s Hospital of Nanning
  • Received:2019-12-04 Revised:2020-06-24 Published:2020-10-15 Online:2020-10-30
  • Contact: Juan Zhong E-mail:zjanny919@163.com

摘要:

摘要:目的 探讨厄贝沙坦调控过氧化物酶体增殖物激活受体γ(PPAR-γ)介导磷酸腺苷依赖的蛋白激酶(AMPK)/哺乳动物雷帕霉素靶蛋白(mTOR)信号通路及自噬对LO2细胞脂肪变的影响。方法 采用脂混合物(LM)诱导LO2细胞建立细胞脂肪变模型,将造模后细胞分为模型组、厄贝沙坦组和厄贝沙坦联合PPAR-γ抑制剂组,另设正常组。分别干预24 h后,采用酶联免疫吸附测定(ELISA)法检测细胞三酰甘油(TG)和总胆固醇(TC)含量,并行油红O染色分析细胞内脂质沉积,通过蛋白免疫印迹法(Western blot)检测细胞PPAR-γ、AMPK/mTOR信号通路相关蛋白的表达,应用激光共聚焦技术观察自噬标志蛋白LC3B的变化。结果 10 μmol/L及以下浓度的厄贝沙坦对LO2细胞生长无明显毒性作用,20 μmol/L厄贝沙坦对细胞毒性作用较大,表现出明显的抑制作用。与正常组比较,模型组LO2细胞内TG和TC含量升高,油红O染色显示脂质大量沉积,PPAR-γ、p-AMPK和LC3B蛋白表达水平降低,mTOR磷酸化水平升高(均P<0.05);与模型组比较,经厄贝沙坦治疗后,LO2细胞内TG和TC含量降低,油红O染色显示脂质沉积减少,PPAR-γ、p-AMPK和LC3B蛋白表达水平升高,mTOR磷酸化水平降低(均P<0.05);但经厄贝沙坦联合PPAR-γ抑制剂干预后,PPAP-γ抑制剂抑制了厄贝沙坦对LO2细胞脂肪变的治疗作用。结论 厄贝沙坦可通过激活PPAR-γ介导的AMPK/mTOR信号通路,促进LM诱导LO2细胞的自噬,从而减轻脂质沉积,改善肝细胞脂肪变。

关键词: 血管紧张素受体拮抗剂, PPARγ, AMP活化蛋白激酶类, 自噬, 厄贝沙坦, AMPK/mTOR通路, LO2细胞, 脂肪变性

Abstract:

Abstract: Objective To investigate the effect of irbesartan on steatosis in LO2 cells by regulating PPAR-γ-mediated AMPK/mTOR signaling pathway and autophagy. Methods The cell model was established by lipid mixture (LM). LO2 model cells were divided into model group, irbesartan group and irbesartan + PPAR-γ antagonist group. The normal cells were served as the normal group. After 24 hours of intervention, the triacylglycerol (TG) and total cholesterol (TC) levels in cells were measured using enzyme-linked immunosorbent assay (ELISA) kits, and cultured cells were stained with oil red O solution to assess the lipid content. The expression levels of PPAR-γ and AMPK/mTOR signaling pathway molecules in cells were detected by Western blot assay, and the changes of autophagy marker protein LC3B were observed by confocal microscopy and Western blot assay. The changes of autophagy marker protein LC3B were observed by laser confocal technique. Results The concentration of irbesartan in 10μmol/L and below had no obvious toxic effect on the growth of LO2 cells, but 20 μmol/L irbesartan had a significant inhibitory effect on cell viability. Compared with the normal group, the intracellular TG and TC levels as well as lipid deposition were significantly increased in model group, the expressions of PPAR-γ, P-AMPK and LC3B proteins were decreased, and the level of phosphorylated mTOR was increased (P<0.05). Compared with the model group, the intracellular TG and TC levels as well as lipid deposition were significantly decreased in irbesartan group. Moreover, it was found that irbesartan strongly increased the expressions of PPAR-γ, p-AMPK and LC3B, and reduced the level of phosphorylated mTOR in LM-induced LO2 cells (P<0.05). However, these effects were reversed by irbesartan and PPAR-γ inhibitor treatment. It was found that irbesartan strongly increased the expressions of PPAR-γ, p-AMPK and LC3B, and reduced the level of phosphorylated mTOR in LM-induced LO2 cells (P<0.05). Conclusion Irbesartan alleviates lipid deposition and hepatic steatosis by activating PPAR-γ mediated AMPK/mTOR signaling pathway, thereby inducing hepatocyte autophagy.

Key words: angiotensin receptor antagonists, PPAR gamma, AMP-activated protein kinases, autophagy, Irbesartan, AMPK/mTOR pathway, LO2 cells, steatosis