Overexpression of homeodomain-interacting protein kinase 2 (HIPK2) attenuates sepsis-mediated liver injury by restoring autophagy

Cell Death Dis. 2018 Aug 28;9(9):847. doi: 10.1038/s41419-018-0838-9.

Abstract

Sepsis is the leading cause of death in intensive care units worldwide. Autophagy has recently been shown to protect against sepsis-induced liver injury. Here, we investigated the roles of homeodomain-interacting protein kinase 2 (HIPK2) in the molecular mechanism of sepsis-induced liver injury. HIPK2 expression was reduced in sepsis-induced liver injury, and HIPK2 overexpression increased the survival rate and improved caecal ligation and puncture (CLP)-induced liver injury by reducing serum and liver aspartate transaminase (AST), alanine transaminase (ALT), and alkaline phosphatase (ALP) levels in mice with sepsis. HIPK2 overexpression significantly decreased CLP-induced release of inflammatory cytokines into the serum and attenuated oxidative stress-associated indicators in mice with CLP-induced liver injury, whereas HIPK2 knockdown produced the opposite results, suggesting that HIPK2 is a negative regulator of sepsis. Furthermore, HIPK2 overexpression inhibited lipopolysaccharide (LPS)-induced apoptosis of primary hepatocytes, increased the autophagic flux, and restored both autophagosome and autolysosome formation in the livers of CLP-induced mice by suppressing calpain signalling. Importantly, HIPK2 overexpression reduced the elevated cytosolic Ca2+ concentration in LPS-treated primary hepatocytes by interacting with calpain 1 and calmodulin. Finally, several anti-inflammatory drugs, including resveratrol, aspirin, vitamin E and ursolic acid, significantly increased the levels of the HIPK2 mRNA and protein by modulating promoter activity and the 3'-UTR stability of the HIPK2 gene. In conclusion, HIPK2 overexpression may improve sepsis-induced liver injury by restoring autophagy and thus might be a promising target for the clinical treatment of sepsis.

MeSH terms

  • Alanine Transaminase / blood
  • Animals
  • Apoptosis / physiology
  • Aspartate Aminotransferases / blood
  • Autophagy / physiology*
  • Carrier Proteins / metabolism*
  • Cytokines / blood
  • Hepatocytes / metabolism
  • Hepatocytes / pathology
  • Inflammation / blood
  • Inflammation / metabolism
  • Inflammation / pathology
  • Liver / metabolism*
  • Liver / pathology
  • Liver Diseases / blood
  • Liver Diseases / etiology
  • Liver Diseases / metabolism*
  • Liver Diseases / pathology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Protein Serine-Threonine Kinases / metabolism*
  • Sepsis / blood
  • Sepsis / complications
  • Sepsis / metabolism*
  • Signal Transduction / physiology

Substances

  • Carrier Proteins
  • Cytokines
  • Aspartate Aminotransferases
  • Alanine Transaminase
  • Hipk2 protein, mouse
  • Protein Serine-Threonine Kinases