Nicotinamide Riboside Exerts Protective Effect Against Aging-Induced NAFLD-like Hepatic Dysfunction in Mice

PeerJ. 2019 Aug 28;7:e7568. doi: 10.7717/peerj.7568. eCollection 2019.

Abstract

Background & aims: Aging is one of the risk factors of non-alcoholic fatty liver disease (NAFLD). Yet, the mechanism underlying the aging-associated NAFLD-like syndrome is not fully understood. Nicotinamide adenine dinucleotide (NAD), a ubiquitous coenzyme, has protective effects against aging. Here, we investigated the actions of NAD precursors nicotinamide riboside (NR) on the development of aging-induced NAFLD.

Methods: NR supplemented food (2.5 g/kg food) was applied to aged mice for three months while normal chow to the other groups. Body weight, food intake, liver weight and fat pat mass were measured. The serum concentrations of lipid content, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and NAD were determined by biochemical assays. Pathological assessment and immunohistochemistry analysis of hepatic tissues were used to evaluate the effect of NR on NAFLD development and inflammatory infiltration.

Results: NR repletion significantly reduced fat pat mass in aged mice, while not altered the body weight, food intake, and liver weight. NR repletion significantly rescued the NAD reduction in aged mice. The total cholesterol and triglyceride levels could be lowered by NR repletion in aged mice. The AST level was also significantly reduced by NR repletion in aged group, while the ALT level lowered but without significance. Notably, moderate NAFLD phenotypes, including steatosis and hepatic fibrosis could be markedly corrected by NR repletion. In addition, Kupffer cells accumulated and inflammatory infiltration could also be remarkably reversed by NR repletion in aged mice.

Conclusion: Aging was associated with NAFLD-like phenotypes in mice, which could be reversed by oral NR repletion. Therefore, oral NR uptake might be a promising strategy to halt the progression of NAFLD.

Keywords: Aged mice; Inflammatory infiltration; Nicotinamide adenine dinucleotide; Nicotinamide riboside; Non-alcoholic fatty liver disease.

Grant support

This study was supported by the Natural Science Foundation of Zhejiang (Grants LGJ18H310002, LQY19H090001, LY18H310009 and LQY18C040001) and the Shanghai Committee of Science and Technology, China (Grant No. 15411951000 and 2018QN13). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.