HSPA12A attenuates lipopolysaccharide-induced liver injury through inhibiting caspase-11-mediated hepatocyte pyroptosis via PGC-1α-dependent acyloxyacyl hydrolase expression

Cell Death Differ. 2020 Sep;27(9):2651-2667. doi: 10.1038/s41418-020-0536-x. Epub 2020 Apr 24.

Abstract

Liver dysfunction is strongly associated with poor survival of sepsis patients. Cytosolic lipopolysaccharide (LPS) sensing by Caspase-4/5/11 for pyroptosis activation is a major driver of the development of sepsis. Studies in macrophages and endothelial cells have demonstrated that LPS is inactivated by acyloxyacyl hydrolase (AOAH) and leading to desensitizing Caspase-4/5/11 to LPS. However, little is known about the cytosolic LPS-induced pyroptosis in hepatocytes during sepsis. Heat shock protein 12A (HSPA12A) is a novel member of the HSP70 family. Here, we report that LPS increased HSPA12A nuclear translocation in hepatocytes, while knockout of HSPA12A (Hspa12a-/-) in mice promoted LPS-induced acute liver injury. We also noticed that the LPS-induced Caspase-11 activation and its cleavage of gasdermin D (GSDMD) to produce the membrane pore-forming GSDMDNterm (markers of pyroptosis) were greater in livers of Hspa12a-/- mice compared with its wild type controls. Loss- and gain-of-function studies showed that HSPA12A deficiency promoted, whereas HSPA12A overexpression inhibited, cytosolic LPS accumulation, Caspase-11 activation and GSDMDNterm generation in primary hepatocytes following LPS incubation. Notably, LPS-induced AOAH expression was suppressed by HSPA12A deficiency, whereas AOAH overexpression reversed the HSPA12A deficiency-induced promotion of LPS-evoked and Caspase-11-mediated pyroptosis of hepatocytes. In-depth molecular analysis showed that HSPA12A interacted directly with peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and increased its nuclear translocation, thereby inducing AOAH expression for cytosolic LPS inactivation, which ultimately leading to inhibition of the Caspase-11 mediated pyroptosis of hepatocytes. Taken together, these findings revealed HSPA12A as a novel player against LPS-induced liver injury by inhibiting cytosolic LPS-induced hepatocyte pyroptosis via PGC-1α-mediated AOAH expression. Therefore, targeting hepatocyte HSPA12A represents a viable strategy for the management of liver injury in sepsis patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carboxylic Ester Hydrolases / metabolism*
  • Caspases, Initiator / metabolism*
  • Cell Nucleus / metabolism
  • Cells, Cultured
  • Cytosol / metabolism
  • HSP70 Heat-Shock Proteins / deficiency
  • HSP70 Heat-Shock Proteins / metabolism*
  • Hepatocytes / pathology*
  • Inflammation / pathology
  • Lipopolysaccharides
  • Liver / injuries*
  • Liver / metabolism*
  • Liver / pathology
  • Mice
  • Mice, Knockout
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha / metabolism*
  • Protective Agents / metabolism
  • Protein Binding
  • Protein Transport
  • Pyroptosis*
  • Up-Regulation

Substances

  • HSP70 Heat-Shock Proteins
  • Hspa12a protein, mouse
  • Lipopolysaccharides
  • Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha
  • Ppargc1a protein, mouse
  • Protective Agents
  • Carboxylic Ester Hydrolases
  • acyloxyacyl hydrolase
  • Casp4 protein, mouse
  • Caspases, Initiator