Hepatic TGFβr1 Deficiency Attenuates Lipopolysaccharide/D-Galactosamine-Induced Acute Liver Failure Through Inhibiting GSK3β-Nrf2-Mediated Hepatocyte Apoptosis and Ferroptosis

Cell Mol Gastroenterol Hepatol. 2022;13(6):1649-1672. doi: 10.1016/j.jcmgh.2022.02.009. Epub 2022 Feb 21.

Abstract

Background & aims: Acute liver failure (ALF) is a condition with high mortality and morbidity, characterized by glutathione depletion, oxidative stress, and mitochondrial dysfunction. Ferroptosis may be involved in ALF. Indeed, emerging studies have shown that ferroptosis plays a significant role in ALF. However, the mechanism of ferroptosis in hepatocytes during ALF remains unknown.

Methods: Hepatic-specific transforming growth factor β receptor 1 knockout (TGFβr1Δhep-CKO) mice and nuclear factor erythroid 2-related factor 2 knockout (Nrf2-/-) mice were generated and subjected to ALF. Electron microscopy was used to detect mitochondrial and other cell substructure changes during ALF.

Results: In this study, we noticed that lipopolysaccharide (LPS)/D-galactosamine (D-GalN) induced caspases-mediated apoptosis as current research reported, we also found lipid peroxidation, reactive oxygen species accumulation, and glutathione, co-enzyme Q10 system inhibition mediated ferroptosis during LPS/D-GalN-induced ALF. Rescue studies have shown that ferrostatin-1 (Fer-1) and deferoxamine mesylate (DFOM), the inhibitor of ferroptosis, could alleviate LPS/D-GalN-induced ALF. In addition, we noticed that TGFβ1 was increased during ALF, while ALF was relieved in TGFβr1Δhep-CKO mice. We also noticed that liver TGFβr1 deficiency alleviated LPS/D-GalN-induced apoptosis and ferroptosis by affecting the phosphorylation of glycogen synthase kinase 3β and Nrf2, a key antioxidant factor, by up-regulating the levels of glutathione peroxidase 4 (GPX4), glutamine antiporter xCT (XCT), dihydroorotate dehydrogenase (DHODH), and ferroptosis suppressor protein 1 (FSP1), and down-regulating transferrin receptor (TFR), prostaglandin-endoperoxide synthase (Ptgs2), chaC glutathione specific gamma-glutamylcyclotransferase 1 (CHAC1), and cytochrome P450 reductase (POR) expression. The further supplemental experiment showed that ferroptosis was aggravated significantly in Nrf2-/- mice compared with its wild-type controls and reversed by ferrostatin-1.

Conclusions: This study shows that TGFβr1 plays a critical role in mediating LPS/D-GalN-induced ALF by promoting apoptosis and ferroptosis.

Keywords: ALF; Apoptosis; Ferroptosis; GSK3β; Nrf2; ROS; TGFβr1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Ferroptosis*
  • Galactosamine / metabolism
  • Galactosamine / toxicity
  • Glutathione / adverse effects
  • Glutathione / metabolism
  • Glycogen Synthase Kinase 3 beta / metabolism
  • Hepatocytes / metabolism
  • Lipopolysaccharides / metabolism
  • Lipopolysaccharides / toxicity
  • Liver Failure, Acute* / chemically induced
  • Liver Failure, Acute* / metabolism
  • Mice
  • Mice, Inbred C57BL
  • NF-E2-Related Factor 2 / metabolism
  • Transforming Growth Factor beta1 / metabolism*

Substances

  • Lipopolysaccharides
  • NF-E2-Related Factor 2
  • Tgfb1 protein, mouse
  • Transforming Growth Factor beta1
  • Galactosamine
  • Glycogen Synthase Kinase 3 beta
  • Glutathione