eNOS deletion impairs mitochondrial quality control and exacerbates Western diet-induced NASH

Am J Physiol Endocrinol Metab. 2019 Oct 1;317(4):E605-E616. doi: 10.1152/ajpendo.00096.2019. Epub 2019 Jul 30.


Dysregulated mitochondrial quality control leads to mitochondrial functional impairments that are central to the development and progression of hepatic steatosis to nonalcoholic steatohepatitis (NASH). Here, we identify hepatocellular localized endothelial nitric oxide synthase (eNOS) as a novel master regulator of mitochondrial quality control. Mice lacking eNOS were more susceptible to Western diet-induced hepatic inflammation and fibrosis in conjunction with decreased markers of mitochondrial biogenesis and turnover. The hepatocyte-specific influence was verified via magnetic activated cell sorting purified primary hepatocytes and in vitro siRNA-induced knockdown of eNOS. Hepatic mitochondria from eNOS knockout mice revealed decreased markers of mitochondrial biogenesis (PPARγ coactivator-1α, mitochondrial transcription factor A) and autophagy/mitophagy [BCL-2-interacting protein-3 (BNIP3), 1A/1B light chain 3B (LC3)], suggesting decreased mitochondrial turnover rate. eNOS knockout in primary hepatocytes exhibited reduced fatty acid oxidation capacity and were unable to mount a normal BNIP3 response to a mitophagic challenge compared with wild-type mice. Finally, we demonstrate that eNOS is required in primary hepatocytes to induce activation of the stress-responsive transcription factor nuclear factor erythroid 2-related factor 2 (NRF2). Thus, our data demonstrate that eNOS is an important regulator of hepatic mitochondrial content and function and NASH susceptibility.

Keywords: NAFLD; endothelial nitric oxide synthase; mitophagy; steatohepatitis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Autophagy / genetics
  • Diet, Western / adverse effects*
  • Gene Knockdown Techniques
  • Hepatocytes / pathology
  • Male
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Mitochondria, Liver / metabolism*
  • Mitochondrial Proteins / biosynthesis
  • Mitochondrial Proteins / genetics
  • Mitophagy
  • NF-E2-Related Factor 2 / biosynthesis
  • NF-E2-Related Factor 2 / genetics
  • Nitric Oxide Synthase Type III / genetics*
  • Non-alcoholic Fatty Liver Disease / genetics*
  • Non-alcoholic Fatty Liver Disease / metabolism*
  • Primary Cell Culture
  • RNA, Small Interfering / pharmacology


  • BNip3 protein, mouse
  • Membrane Proteins
  • Mitochondrial Proteins
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • RNA, Small Interfering
  • Nitric Oxide Synthase Type III
  • Nos3 protein, mouse