Suppression of insulin-induced gene 1 (INSIG1) function promotes hepatic lipid remodelling and restrains NASH progression
File(s)Suppression of insulin-induced gene.pdf (3.46 MB)
Published version
Author(s)
Type
Journal Article
Abstract
OBJECTIVE: Non-alcoholic fatty liver disease (NAFLD) is a silent pandemic associated with obesity and the metabolic syndrome, and also increases cardiovascular- and cirrhosis-related morbidity and mortality. A complete understanding of adaptive compensatory metabolic programmes that modulate non-alcoholic steatohepatitis (NASH) progression is lacking. METHODS AND RESULTS: Transcriptomic analysis of liver biopsies in patients with NASH revealed that NASH progression is associated with rewiring of metabolic pathways, including upregulation of de novo lipid/cholesterol synthesis and fatty acid remodelling. The modulation of these metabolic programmes was achieved by activating sterol regulatory element-binding protein (SREBP) transcriptional networks; however, it is still debated whether, in the context of NASH, activation of SREBPs acts as a pathogenic driver of lipotoxicity, or rather promotes the biosynthesis of protective lipids that buffer excessive lipid accumulation, preventing inflammation and fibrosis. To elucidate the pathophysiological role of SCAP/SREBP in NASH and wound-healing response, we used an Insig1 deficient (with hyper-efficient SREBPs) murine model challenged with a NASH-inducing diet. Despite enhanced lipid and cholesterol biosynthesis, Insig1 KO mice had similar systemic metabolism and insulin sensitivity to Het/WT littermates. Moreover, activating SREBPs resulted in remodelling the lipidome, decreased hepatocellular damage, and improved wound-healing responses. CONCLUSIONS: Our study provides actionable knowledge about the pathways and mechanisms involved in NAFLD pathogenesis, which may prove useful for developing new therapeutic strategies. Our results also suggest that the SCAP/SREBP/INSIG1 trio governs transcriptional programmes aimed at protecting the liver from lipotoxic insults in NASH.
Date Issued
2021-06-01
Date Acceptance
2021-03-06
Citation
Molecular Metabolism, 2021, 48 (1), pp.1-10
ISSN
2212-8778
Publisher
Elsevier
Start Page
1
End Page
10
Journal / Book Title
Molecular Metabolism
Volume
48
Issue
1
Copyright Statement
© 2021 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
License URL
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/33722690
PII: S2212-8778(21)00050-8
Subjects
Carbon tetrachloride (CCl(4))
De novo lipogenesis (DNL)
Lipid remodelling
Liver regeneration
Non-alcoholic fatty liver disease (NAFLD)
Western diet
Publication Status
Published
Coverage Spatial
Germany
Article Number
101210
Date Publish Online
2021-03-17