Antagonizing circRNA_002581-miR-122-CPEB1 axis alleviates NASH through restoring PTEN-AMPK-mTOR pathway regulated autophagy

Cell Death Dis. 2020 Feb 13;11(2):123. doi: 10.1038/s41419-020-2293-7.

Abstract

Circular RNAs (circRNAs) have been shown to play critical roles in cancer biology, but their functions in nonalcoholic steatohepatitis (NASH) remain unexplored. Full length of circRNA_002581 was amplified and sequenced, followed by RNA immunoprecipitation, RNA-Fluorescence in Situ Hybridization and dual luciferase reporter gene analysis to confirm the existence of the circRNA_002581-miR-122-CPEB1 regulatory axis in vitro. CircRNA_002581 knockdown was used to study its roles in high concentration of free fatty acids-induced NASH-like cell model and a methionine and choline deficiency (MCD) diet-induced NASH mice model. Autophagy flux and related potential PTEN-AMPK-mTOR pathway were tested by western blot. CircRNA_002581 overexpression significantly relieved the inhibitory role of miR-122 on its target CPEB1 by sponging miR-122. CircRNA_002581 knockdown markedly attenuated lipid droplet accumulation, reduced the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), pro-inflammatory cytokines, apoptosis, H2O2, and increased ATP level in both mice and cellular models of NASH. Mechanistically, circRNA_002581 interference significantly rescue the defective autophagy evidenced by increased autophagosome number, upregulated LC3-II/I level, and decreased p62 level. Further chloroquine-mediated total autophagy inhibition antagonizes the protective effect of circRNA_002581 knockdown. Finally, CPEB1-PTEN-AMPK-mTOR pathway is shown to link the autophagy and circRNA_002581 knockdown-mediated NASH alleviation. CircRNA_002581-miR-122-CPEB1 axis actively participates in the pathogenesis of NASH through PTEN-AMPK-mTOR pathway-related autophagy suppression. Targeting circRNA_002581 is a potential therapeutic strategy for NASH through partial autophagy restoration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Autophagy / drug effects*
  • Disease Models, Animal
  • Gene Expression Regulation
  • HEK293 Cells
  • Humans
  • Liver / enzymology*
  • Liver / pathology
  • Male
  • Mice, Inbred BALB C
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Non-alcoholic Fatty Liver Disease / enzymology
  • Non-alcoholic Fatty Liver Disease / genetics
  • Non-alcoholic Fatty Liver Disease / pathology
  • Non-alcoholic Fatty Liver Disease / prevention & control*
  • PTEN Phosphohydrolase / metabolism*
  • RNA Interference*
  • RNA, Circular / genetics
  • RNA, Circular / metabolism*
  • Signal Transduction
  • TOR Serine-Threonine Kinases / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • mRNA Cleavage and Polyadenylation Factors / genetics
  • mRNA Cleavage and Polyadenylation Factors / metabolism*

Substances

  • Cpeb1 protein, mouse
  • MicroRNAs
  • Mirn122 microRNA, mouse
  • RNA, Circular
  • Transcription Factors
  • mRNA Cleavage and Polyadenylation Factors
  • mTOR protein, mouse
  • TOR Serine-Threonine Kinases
  • AMP-Activated Protein Kinases
  • PTEN Phosphohydrolase
  • Pten protein, mouse