A1 Journal article – refereed
Adipose Tissue Dysfunction and Altered Systemic Amino Acid Metabolism Are Associated with Non-Alcoholic Fatty Liver Disease




List of Authors: Sulin Cheng, Petri Wiklund, Reija Autio, Ronald Borra, Xiaowei Ojanen, Leiting Xu, Timo Törmäkangas, Markku Alen
Publisher: Public Library of Science
Publication year: 2015
Journal: PLoS ONE
Journal name in source: PLOS ONE
Journal acronym: PLOS ONE
Volume number: 10
Issue number: 10
ISSN: 1932-6203
eISSN: 1932-6203

Abstract


Background



Fatty liver is a major cause of obesity-related morbidity and mortality. The aim of this study was to identify early metabolic alterations associated with liver fat accumulation in 50- to 55-year-old men (n = 49) and women (n = 52) with and without NAFLD.



Methods



Hepatic fat content was measured using proton magnetic resonance spectroscopy (1H MRS). Serum samples were analyzed using a nuclear magnetic resonance (NMR) metabolomics platform. Global gene expression profiles of adipose tissues and skeletal muscle were analyzed using Affymetrix microarrays and quantitative PCR. Muscle protein expression was analyzed by Western blot.



Results



Increased branched-chain amino acid (BCAA), aromatic amino acid (AAA) and orosomucoid were associated with liver fat accumulation already in its early stage, independent of sex, obesity or insulin resistance (p<0.05 for all). Significant down-regulation of BCAA catabolism and fatty acid and energy metabolism was observed in the adipose tissue of the NAFLD group (p<0.001for all), whereas no aberrant gene expression in the skeletal muscle was found. Reduced BCAA catabolic activity was inversely associated with serum BCAA and liver fat content (p<0.05 for all).



Conclusions



Liver fat accumulation, already in its early stage, is associated with increased serum branched-chain and aromatic amino acids. The observed associations of decreased BCAA catabolism activity, mitochondrial energy metabolism and serum BCAA concentration with liver fat content suggest that adipose tissue dysfunction may have a key role in the systemic nature of NAFLD pathogenesis.




Internal Authors/Editors

Last updated on 2019-20-07 at 04:23