Cysteine cathepsins control hepatic NF-κB-dependent inflammation via sirtuin-1 regulation

Cell Death Dis. 2016 Nov 10;7(11):e2464. doi: 10.1038/cddis.2016.368.

Abstract

Sirtuin-1 (SIRT1) regulates hepatic metabolism but its contribution to NF-κB-dependent inflammation has been overlooked. Cysteine cathepsins (Cathepsin B or S, CTSB/S) execute specific functions in physiological processes, such as protein degradation, having SIRT1 as a substrate. We investigated the roles of CTSB/S and SIRT1 in the regulation of hepatic inflammation using primary parenchymal and non-parenchymal hepatic cell types and cell lines. In all cells analyzed, CTSB/S inhibition reduces nuclear p65-NF-κB and κB-dependent gene expression after LPS or TNF through enhanced SIRT1 expression. Accordingly, SIRT1 silencing was sufficient to enhance inflammatory gene expression. Importantly, in a dietary mouse model of non-alcoholic steatohepatitis, or in healthy and fibrotic mice after LPS challenge, cathepsins as well as NF-κB-dependent gene expression are activated. Consistent with the prominent role of cathepsin/SIRT1, cysteine cathepsin inhibition limits NF-κB-dependent hepatic inflammation through the regulation of SIRT1 in all in vivo settings, providing a novel anti-inflammatory therapeutic target in liver disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cathepsin B / metabolism*
  • Cathepsins / metabolism*
  • Cells, Cultured
  • Disease Models, Animal
  • Gene Expression Regulation / drug effects
  • Hepatic Stellate Cells / drug effects
  • Hepatic Stellate Cells / metabolism
  • Hepatocytes / drug effects
  • Hepatocytes / metabolism
  • Humans
  • Inflammation / genetics
  • Inflammation / metabolism*
  • Inflammation / pathology
  • Lipopolysaccharides / pharmacology
  • Liver / metabolism*
  • Liver / pathology*
  • Liver Cirrhosis / complications
  • Liver Cirrhosis / metabolism
  • Liver Cirrhosis / pathology
  • Male
  • Mice, Inbred C57BL
  • NF-kappa B / metabolism*
  • Non-alcoholic Fatty Liver Disease / complications
  • Non-alcoholic Fatty Liver Disease / metabolism
  • Non-alcoholic Fatty Liver Disease / pathology
  • Phenotype
  • Protein Processing, Post-Translational / drug effects
  • Sirtuin 1 / metabolism*

Substances

  • Lipopolysaccharides
  • NF-kappa B
  • Cathepsins
  • Cathepsin B
  • cathepsin S
  • Sirtuin 1