Bmal1 inhibits phenotypic transformation of hepatic stellate cells in liver fibrosis via IDH1/α-KG-mediated glycolysis

Acta Pharmacol Sin. 2022 Feb;43(2):316-329. doi: 10.1038/s41401-021-00658-9. Epub 2021 Apr 13.

Abstract

Hepatic stellate cells (HSCs) play an important role in the initiation and development of liver fibrogenesis, and abnormal glucose metabolism is increasingly being considered a crucial factor controlling phenotypic transformation in HSCs. However, the role of the factors affecting glycolysis in HSCs in the experimental models of liver fibrosis has not been completely elucidated. In this study, we showed that glycolysis was significantly enhanced, while the expression of brain and muscle arnt-like protein-1 (Bmal1) was downregulated in fibrotic liver tissues of mice, primary HSCs, and transforming growth factor-β1 (TGF-β1)-induced LX2 cells. Overexpression of Bmal1 in TGF-β1-induced LX2 cells blocked glycolysis and inhibited the proliferation and phenotypic transformation of activated HSCs. We further confirmed the protective effect of Bmal1 in liver fibrosis by overexpressing Bmal1 from hepatic adeno-associated virus 8 in mice. In addition, we also showed that the regulation of glycolysis by Bmal1 is mediated by the isocitrate dehydrogenase 1/α-ketoglutarate (IDH1/α-KG) pathway. Collectively, our results indicated that a novel Bmal1-IDH1/α-KG axis may be involved in regulating glycolysis of activated HSCs and might hence be used as a therapeutic target for alleviating liver fibrosis.

Keywords: Bmal1; HSCs; IDH1; glycolysis; liver fibrosis; α-KG.

MeSH terms

  • ARNTL Transcription Factors / metabolism*
  • ARNTL Transcription Factors / physiology
  • Animals
  • Blotting, Western
  • Chromatography, High Pressure Liquid
  • Flow Cytometry
  • Glycolysis*
  • Hepatic Stellate Cells / metabolism*
  • Hepatic Stellate Cells / pathology
  • Isocitrate Dehydrogenase / metabolism*
  • Liver Cirrhosis / metabolism*
  • Liver Cirrhosis / physiopathology
  • Male
  • Mass Spectrometry
  • Mice
  • Mice, Inbred C57BL

Substances

  • ARNTL Transcription Factors
  • Bmal1 protein, mouse
  • Isocitrate Dehydrogenase
  • Idh1 protein, mouse