Longitudinal study of circulating miR-122 in a rat model of non-alcoholic fatty liver disease

• Published in: Clinica chimica acta Vol. 446; pp. 267 - 271
• Main Authors: Yamada, Hiroya, Ohashi, Koji, Suzuki, Koji, Munetsuna, Eiji, Ando, Yoshitaka, Yamazaki, Mirai, Ishikawa, Hiroaki, Ichino, Naohiro, Teradaira, Ryouji, Hashimoto, Shuji
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.06.2015
• Subjects: Alanine Transaminase - blood; Animals; Aspartate Aminotransferases - blood; Azo Compounds; Biomarkers - blood; Cholesterol - blood; Circulating miRNA; Diet, High-Fat; Disease Models, Animal; Early Diagnosis; Fatty Acids, Nonesterified - blood; Histocytochemistry; Humans; Liver - metabolism; Liver - pathology; Longitudinal Studies; Male; MicroRNAs - blood; miR-122; Non-alcoholic fatty liver disease; Non-alcoholic Fatty Liver Disease - blood; Non-alcoholic Fatty Liver Disease - diagnosis; Non-alcoholic Fatty Liver Disease - etiology; Non-alcoholic Fatty Liver Disease - pathology; Rats; Rats, Sprague-Dawley; Serum miRNA; Triglycerides - blood; Serum miRNA; Circulating miRNA; Non-alcoholic fatty liver disease; miR-122
• ISSN: 0009-8981; 1873-3492
• DOI: 10.1016/j.cca.2015.05.002

Circulating microRNAs (miRs) may be promising biomarkers for several diseases. We previously found that miR-122 can function as a biomarker for non-alcoholic fatty liver disease (NAFLD). However, little is known regarding the time course of circulating miR-122 levels during the development of NAFLD. Here, we examined circulating miR-122 levels using a rat model of NAFLD. To clarify changes in serum levels of miR-122 during development of NAFLD, experimental rats were fed a high-fat diet (HFD) for 2–10weeks, while control rats received standard chow. Serum and liver tissue was collected from all animals at 2, 6, and 10weeks of feeding. Clinical laboratory parameters (cholesterol, TG, AST, ALT, NEFA) were determined by biochemistry analyzer. Hepatic lipid accumulation was estimated by Oil red O staining. Circulating miR-122 levels were then measured by real-time polymerase chain reaction. Over the 10weeks of feeding, body weight, total liver lipids, and liver and serum triacylglycerol were increased in the HFD group compared to the control group. However, no significant changes in serum alanine aminotransferase activity were observed, suggesting that NAFLD status was mild. In contrast, we observed drastic up-regulation of circulating miR-122 levels. Our findings suggest that serum miR-122 level is indeed useful for assessing early NAFLD and might be superior to clinical markers traditionally used to monitor hepatic disease. •Circulating miR-122 can function as a biomarker for non-alcoholic fatty liver disease (NAFLD).•We attempt to clarify changes in serum levels of miR-122 during development of NAFLD•We observed drastic up-regulation of circulating miR-122 levels.•Circulating miR-122 level might be superior to clinical markers traditionally used to monitor hepatic disease.