Changes in white and brown adipose tissue microRNA expression in cold-induced mice

There are two classic adipose tissues in mammals, white adipose tissue (WAT) and brown adipose tissue (BAT). It has been well known that browning of WAT can be induced by cold exposure. In this study, to identify the novel cold responsive key miRNAs that are involved in browning, mice were housed at 6 °C for 10 days, and deep sequencing of the miRNAs of WAT and BAT was performed. Our data showed that WAT and BAT displayed distinct expression profiles due to their different locations, morphology and biological function. A total of 27 BAT and 29 WAT differentially expressed (DE) miRNAs were identified in response to cold stimulation, respectively (fold change >2 and false discovery rate (FDR) <0.05), of which, 9 were overlapped in both adipose tissues. Furthermore, the potential target genes of the DE miRNAs from BAT and WAT were predicted computationally, and the KEGG pathway analysis revealed the enrichment pathways in cold stimulated adipose tissues. The expression pattern of miR-144-3p/Bmpr1b/Phlda1 and miR-146a-5p/Sphk2 were further measured by qPCR. Finally, we found that miR-146a-5p was significantly induced during the primary adipogenesis caused by BAT differentiation, whereas miR-144-3p was decreased. Our study identifies for the first time the novel miRNAs involved in browning of WAT by sequencing and expands the therapeutic approaches for combating metabolic diseases.