Role of autophagy in betaine-promoted hepatoprotection against non-alcoholic fatty liver disease in mice

• Published in: Current research in food science Vol. 8; p. 100663
• Main Authors: Seo, Jinuk, Kwon, Doyoung, Kim, Sou Hyun, Byun, Mi Ran, Lee, Yun-Hee, Jung, Young-Suk
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2024; Elsevier
• Subjects: Apoptosis; Autophagy; Betaine; Endoplasmic reticulum stress; Non-alcoholic fatty liver disease; S-amino acid metabolism; Non-alcoholic fatty liver disease; S-amino acid metabolism; Betaine; Autophagy; Endoplasmic reticulum stress; Apoptosis
• ISSN: 2665-9271; 2665-9271
• DOI: 10.1016/j.crfs.2023.100663

Betaine, a compound found in plants and sea foods, is known to be beneficial against non-alcoholic fatty liver disease (NAFLD), but its hepatoprotective and anti-steatogenic mechanisms have been not fully understood. In the present study, we investigated the mechanisms underlying betaine-mediated alleviation of NAFLD induced by a choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD) in mice, with special focus on the contribution of betaine-stimulated autophagy to NAFLD prevention. Male ICR mice were fed a CDAHFD with or without betaine (0.2–1% in drinking water) for 1 week. Betaine ameliorated the CDAHFD-induced fatty liver by restoring sulfur amino acid (SAA)-related metabolites, such as S-adenosylmethionine and homocysteine, and the phosphorylation of AMPK and ACC. In addition, it reduced the CDAHFD-induced ER stress (BiP, ATF6, and CHOP) and apoptosis (Bax, cleaved caspase-3, and cleaved PARP); however, it induced autophagy (LC3II/I and p62) which was downregulated by CDAHFD. To determine the role of autophagy in the improvement of NAFLD, chloroquine (CQ), an autophagy inhibitor, was injected into the mice fed a CDAHFD and betaine (0.5 % in drinking water). CQ did not affect SAA metabolism but reduced the beneficial effects of betaine as shown by the increases of hepatic lipids, ER stress, and apoptosis. Notably, the betaine-induced improvements in lipid metabolism determined by protein levels of p-AMPK, p-ACC, PPARα, and ACS1, were reversed by CQ. Thus, the results of this study suggest that the activation of autophagy is an important upstream mechanism for the inhibition of steatosis, ER stress, and apoptosis by betaine in NAFLD. [Display omitted] •Betaine attenuates choline-deficient, amino acid-defined, high-fat diet-induced NAFLD.•Betaine restores the dysregulation of hepatic S-amino acid metabolism in NAFLD.•Betaine improves hepatic autophagy, steatosis, ER stress, and apoptosis in NAFLD.•Inhibition of autophagy by chloroquine suppresses betaine-promoted hepatoprotection.•Betaine protects the liver from CDAHFD-induced NAFLD.