MiR-93 Controls Adiposity via Inhibition of Sirt7 and Tbx3

• Knockout of the miR-25-93-106b cluster increased fat mass and insulin resistance
• MiR-93 controls Tbx3 and thereby limits self-renewal of early adipocyte precursors
• MiR-93 further inhibits the metabolic target Sirt7 and thus in vivo adipogenesis
• (Circulating) miR-93 reduced obesity in miR-25-93-106b KO and ob/ob mice

SummaryConquering obesity has become a major socioeconomic challenge. Here, we show that reduced expression of the miR-25-93-106b cluster, or miR-93 alone, increases fat mass and, subsequently, insulin resistance. Mechanistically, we discovered an intricate interplay between enhanced adipocyte precursor turnover and increased adipogenesis. First, miR-93 controls Tbx3, thereby limiting self-renewal in early adipocyte precursors. Second, miR-93 inhibits the metabolic target Sirt7, which we identified as a major driver of in vivo adipogenesis via induction of differentiation and maturation of early adipocyte precursors. Using mouse parabiosis, obesity in mir-25-93-106b–/– mice could be rescued by restoring levels of circulating miRNA and subsequent inhibition of Tbx3 and Sirt7. Downregulation of miR-93 also occurred in obese ob/ob mice, and this phenocopy of mir-25-93-106b–/– was partially reversible with injection of miR-93 mimics. Our data establish miR-93 as a negative regulator of adipogenesis and a potential therapeutic option for obesity and the metabolic syndrome.

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