Deubiquitinating modification of proteins is involved in the pathogenesis and development of diseases. Here, we investigated the role and regulating mechanism of a deubiquitinating enzyme (DUB), ovarian tumor domain-containing protein 1 (OTUD1), in d

Deubiquitinating modification of proteins is involved in the pathogenesis and development of diseases. Here, we investigated the role and regulating mechanism of a deubiquitinating enzyme (DUB), ovarian tumor domain-containing protein 1 (OTUD1), in diabetic cardiomyopathy (DCM). We found a significantly increased OTUD1 expression in diabetic mouse hearts, and single-cell RNA sequencing showed that OTUD1 was mainly distributed in cardiomyocytes. Cardiomyocyte-specific OTUD1 knockout efficiently prevents cardiac hypertrophy and dysfunction in both type 2 and type 1 diabetic mice. RNA-seq analysis showed that OTUD1 deficiency restored cardiac AMPK activity and mitochondrial function in diabetic mouse hearts. In vitro investigations validated that OTUD1 promoted mitochondrial injuries and hypertrophy in cardiomyocytes through negatively regulating AMPK. Mechanistically, we found that OTUD1 directly bound to the kinase domain of AMPKa2 subunit. OTUD1 deubiquitinates AMPKa2 at K60/K379 sites, and then inhibits AMPKT172 phosphorylation through impeding the interaction of AMPKa2 and its upstream kinase CamKK2. Finally, silencing AMPKa2 in cardiomyocytes abolishes the cardioprotective effects of OTUD1 deficiency in diabetic mice. In conclusion, this work identified for the first time a direct regulating DUB of AMPK and presents a new OTUD1-AMPK axis in cardiomyocytes for driving DCM, suggesting that targeting OTUD1 may be an attractive therapeutic strategy for DCM.