Butyrate Protects against Diet-Induced NASH and Liver Fibrosis and Suppresses Specific Non-Canonical TGF-β Signaling Pathways in Human Hepatic Stellate Cells

• Published in: Biomedicines Vol. 9; no. 12; p. 1954
• Main Authors: Gart, Eveline, van Duyvenvoorde, Wim, Toet, Karin, Caspers, Martien P M, Verschuren, Lars, Nielsen, Mette Juul, Leeming, Diana Julie, Souto Lima, Everton, Menke, Aswin, Hanemaaijer, Roeland, Keijer, Jaap, Salic, Kanita, Kleemann, Robert, Morrison, Martine C
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 20.12.2021; MDPI
• Subjects: 1-Phosphatidylinositol 3-kinase; Adipocytes; Adipose tissue; AKT protein; Antibiotics; Body fat; butyrate; Chemokines; Cholesterol; Collagen; Colon; Cytotoxicity; Deactivation; Diet; Dysbacteriosis; Experiments; Fatty liver; Fibrosis; Food; Gene expression; hepatic stellate cells; Histopathology; Hyperinsulinemia; Inflammation; Insulin; Insulin resistance; Laboratory animals; Leptin; Liver; liver fibrosis; Metabolism; Microbiota; Myc protein; non-alcoholic steatohepatitis; Obesity; Permeability; Proteins; Signal transduction; Small intestine; Sodium; Steatosis; Stellate cells; Transcriptomics; Transforming growth factor-b; Triglycerides; Yes-associated protein; United States > US; Netherlands; hepatic stellate cells; liver fibrosis; butyrate; adipose tissue inflammation; gut; collagen; obesity; non-alcoholic steatohepatitis
• ISSN: 2227-9059; 2227-9059
• DOI: 10.3390/biomedicines9121954

In obesity-associated non-alcoholic steatohepatitis (NASH), persistent hepatocellular damage and inflammation are key drivers of fibrosis, which is the main determinant of NASH-associated mortality. The short-chain fatty acid butyrate can exert metabolic improvements and anti-inflammatory activities in NASH. However, its effects on NASH-associated liver fibrosis remain unclear. Putative antifibrotic effects of butyrate were studied in Ldlr-/-.Leiden mice fed an obesogenic diet (HFD) containing 2.5% ( / ) butyrate for 38 weeks and compared with a HFD-control group. Antifibrotic mechanisms of butyrate were further investigated in TGF-β-stimulated primary human hepatic stellate cells (HSC). HFD-fed mice developed obesity, insulin resistance, increased plasma leptin levels, adipose tissue inflammation, gut permeability, dysbiosis, and NASH-associated fibrosis. Butyrate corrected hyperinsulinemia, lowered plasma leptin levels, and attenuated adipose tissue inflammation, without affecting gut permeability or microbiota composition. Butyrate lowered plasma ALT and CK-18M30 levels and attenuated hepatic steatosis and inflammation. Butyrate inhibited fibrosis development as demonstrated by decreased hepatic collagen content and Sirius-red-positive area. In TGF-β-stimulated HSC, butyrate dose-dependently reduced collagen deposition and decreased procollagen1α1 and PAI1 protein expression. Transcriptomic analysis and subsequent pathway and upstream regulator analysis revealed deactivation of specific non-canonical TGF-β signaling pathways Rho-like GTPases and PI3K/AKT and other important pro-fibrotic regulators (e.g., YAP/TAZ, MYC) by butyrate, providing a potential rationale for its antifibrotic effects. In conclusion, butyrate protects against obesity development, insulin resistance-associated NASH, and liver fibrosis. These antifibrotic effects are at least partly attributable to a direct effect of butyrate on collagen production in hepatic stellate cells, involving inhibition of non-canonical TGF-β signaling pathways.