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

Abstract

<div class="section"> <a class="named-anchor" id="S1"> <!-- named anchor --> </a> <h5 class="section-title" id="d6871359e211">Objective:</h5> <p id="P3">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. </p> </div><div class="section"> <a class="named-anchor" id="S2"> <!-- named anchor --> </a> <h5 class="section-title" id="d6871359e216">Results:</h5> <p id="P4">We found that C3H/HePas mice exposed to ALAN developed obesity, and hepatic steatosis, which was paralleled by decreased expression of <i>Rev-erb</i>α and upregulation of its lipogenic targets ACL and FAS in liver. Furthermore, the expression of <i>Rev-erb</i>α-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 <i>Rev-erb</i>α-targeting miRNAs increased mRNA levels of <i>Acly</i> and <i>Fasn</i>. </p> </div><div class="section"> <a class="named-anchor" id="S3"> <!-- named anchor --> </a> <h5 class="section-title" id="d6871359e236">Conclusion:</h5> <p id="P5">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. </p> </div>