Spred2 Deficiency Exacerbates D-Galactosamine/Lipopolysaccharide -induced Acute Liver Injury in Mice via Increased Production of TNFα

Sci Rep. 2018 Jan 9;8(1):188. doi: 10.1038/s41598-017-18380-0.

Abstract

Acute liver injury (ALI) is characterized by hepatocyte damage and inflammation. In the present study, we examined whether the absence of Sprouty-related EVH1-domain-containing protein 2 (Spred2), a negative regulator of the Ras/Raf/ERK/MAPK pathway, influences ALI induced by D-galactosamine (D-GalN) and lipopolysaccharide (LPS). Compared to wild-type mice, Spred2-/- mice developed exacerbated liver injury represented by enhanced hepatocyte damage and inflammation. Enhanced ERK activation was observed in Spred2-/--livers, and the MEK/ERK inhibitor U0126 ameliorated ALI. Hepatic tumour necrosis factor α (TNFα) and interleukin (IL)-1β levels were increased in Spred-2-/--livers, and the neutralization of TNFα dramatically ameliorated ALI, which was associated with decreased levels of endogenous TNFα and IL-1β. When mice were challenged with D-GalN and TNFα, much severer ALI was observed in Spred2-/- mice with significant increases in endogenous TNFα and IL-1β in the livers. Immunohistochemically, Kupffer cells were found to produce TNFα, and isolated Kupffer cells from Spred2-/- mice produced significantly higher levels of TNFα than those from wild-type mice after LPS stimulation, which was significantly decreased by U0126. These results suggest that Spred2 negatively regulates D-GalN/LPS-induced ALI under the control of TNFα in Kupffer cells. Spred2 may present a therapeutic target for the treatment of ALI.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cells, Cultured
  • Galactosamine / toxicity
  • Hepatocytes / metabolism
  • Interleukin-1beta / genetics
  • Interleukin-1beta / metabolism
  • Kupffer Cells / metabolism
  • Lipopolysaccharides / toxicity
  • Liver Failure / etiology
  • Liver Failure / genetics
  • Liver Failure / metabolism*
  • MAP Kinase Signaling System
  • Mice
  • Mice, Inbred C57BL
  • Repressor Proteins / deficiency
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Interleukin-1beta
  • Lipopolysaccharides
  • Repressor Proteins
  • Spred2 protein, mouse
  • Tumor Necrosis Factor-alpha
  • Galactosamine