Nighttime light exposure enhances Rev-erb α-targeting microRNAs and contributes to hepatic steatosis

Abstract

Objective:

The exposure to artificial light at night (ALAN) disrupts the biological rhythms and has been associated with the development of metabolic syndrome. MicroRNAs (miRNAs) display a critical role in fine-tuning the circadian system and energy metabolism. In this study, we aimed to assess whether altered miRNAs expression in the liver underlies metabolic disorders caused by disrupted biological rhythms.

Results:

We found that C3H/HePas mice exposed to ALAN developed obesity, and hepatic steatosis, which was paralleled by decreased expression of Rev-erbα and upregulation of its lipogenic targets ACL and FAS in liver. Furthermore, the expression of Rev-erbα-targeting miRNAs, miR-140–5p, 185–5p, 326–5p and 328–5p were increased in this group. Consistently, overexpression of these miRNAs in primary hepatocytes reduced Rev-erbα expression at the mRNA and protein levels. Importantly, overexpression of Rev-erbα-targeting miRNAs increased mRNA levels of Acly and Fasn.

Conclusion:

Thus, altered miRNA profile is an important mechanism underlying the disruption of the peripheral clock caused by exposure to ALAN, which could lead to hepatic steatosis.