Pnpla3 silencing with antisense oligonucleotides ameliorates nonalcoholic steatohepatitis and fibrosis in Pnpla3 I148M knock-in mice

Mol Metab. 2019 Apr;22:49-61. doi: 10.1016/j.molmet.2019.01.013. Epub 2019 Feb 5.

Abstract

Objective: Nonalcoholic fatty liver disease (NAFLD) is becoming a leading cause of advanced chronic liver disease. The progression of NAFLD, including nonalcoholic steatohepatitis (NASH), has a strong genetic component, and the most robust contributor is the patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 encoding the 148M protein sequence variant. We hypothesized that suppressing the expression of the PNPLA3 148M mutant protein would exert a beneficial effect on the entire spectrum of NAFLD.

Methods: We examined the effects of liver-targeted GalNAc3-conjugated antisense oligonucleotide (ASO)-mediated silencing of Pnpla3 in a knock-in mouse model in which we introduced the human PNPLA3 I148M mutation.

Results: ASO-mediated silencing of Pnpla3 reduced liver steatosis (p = 0.038) in homozygous Pnpla3 148M/M knock-in mutant mice but not in wild-type littermates fed a steatogenic high-sucrose diet. In mice fed a NASH-inducing diet, ASO-mediated silencing of Pnpla3 reduced liver steatosis score and NAFLD activity score independent of the Pnpla3 genotype, while reductions in liver inflammation score (p = 0.018) and fibrosis stage (p = 0.031) were observed only in the Pnpla3 knock-in 148M/M mutant mice. These responses were accompanied by reduced liver levels of Mcp1 (p = 0.026) and Timp2 (p = 0.007) specifically in the mutant knock-in mice. This may reduce levels of chemokine attracting inflammatory cells and increase the collagenolytic activity during tissue regeneration.

Conclusion: This study provides the first evidence that a Pnpla3 ASO therapy can improve all features of NAFLD, including liver fibrosis, and suppress the expression of a strong innate genetic risk factor, Pnpla3 148M, which may open up a precision medicine approach in NASH.

Keywords: Fibrosis; Liver; NAFLD; NASH; PNPLA3.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Female
  • Gene Silencing
  • Humans
  • Lipase / genetics*
  • Lipase / metabolism
  • Liver Cirrhosis / genetics*
  • Liver Cirrhosis / metabolism
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Non-alcoholic Fatty Liver Disease / genetics*
  • Non-alcoholic Fatty Liver Disease / metabolism
  • Oligonucleotides, Antisense / genetics*
  • Oligonucleotides, Antisense / metabolism
  • Phospholipases A2, Calcium-Independent / genetics*
  • Phospholipases A2, Calcium-Independent / metabolism

Substances

  • Membrane Proteins
  • Oligonucleotides, Antisense
  • Lipase
  • PNPLA3 protein, mouse
  • adiponutrin, human
  • Phospholipases A2, Calcium-Independent