MicroRNA miR-7 and miR-17-92 in POMC neurons are associated with sex-specific regulation of diet-induced obesity

Proopiomelanocortin (POMC) neurons in the arcuate nucleus (ARC) in mammalian hypothalamus play important roles in regulating appetite, energy expenditure, and glucose and fat metabolisms. Diet-induced obesity often show sex-specific difference. But the underlying mechanisms remain unclear. Here we show that microRNA (miRNA) miR-7 and miR-17-92 are expressed in the mouse ARC, and mostly in POMC neurons. Knockdown of miR-7 and knockout of miR-17-92 specifically in POMC neurons aggravate diet-induced obesity only in females and males, respectively. Moreover, gene expression profile analysis identifies sex-differential genes in male and female ARCs in wildtype adult mice. Interestingly, these genes that normally show low-expression in the female and male ARCs display upregulated expression in female miR-7 knockdown and male miR-17-92 knockout mice, respectively. Our results demonstrate an important role of miRNAs in regulating sex-specific diet-induced obesity, likely through modulating expression of target genes that show sex-differential expression in the ARC of hypothalamus.