Rna M⁶ a Methylation Regulates Glycolysis of Beige Fat and Contributes to Systemic Metabolic Homeostasis

N6-methyladenosine (m⁶ A) modification has been implicated in the progression of obesity and metabolic diseases. However, its impact on beige fat biology is not well understood. Here, via m⁶ A-sequencing and RNA-sequencing, this work reports that upon beige adipocytes activation, glycolytic genes undergo major events of m⁶ A modification and transcriptional activation. Genetic ablation of m⁶ A writer Mettl3 in fat tissues reveals that Mettl3 deficiency in mature beige adipocytes leads to suppressed glycolytic capability and thermogenesis, as well as reduced preadipocytes proliferation via glycolytic product lactate. In addition, specific modulation of Mettl3 in beige fat via AAV delivery demonstrates consistently Mettl3's role in glucose metabolism, thermogenesis, and beige fat hyperplasia. Mechanistically, Mettl3 and m⁶ A reader Igf2bp2 control mRNA stability of key glycolytic genes in beige adipocytes. Overall, these findings highlight the significance of m⁶ A on fat biology and systemic energy homeostasis.