Celastrol induces cardiotoxicity by directly targeting AMOTL2 and inhibiting YAP1/PGC-1α/TFAM-dependent mitochondrial...

Celastrol is a promising therapeutic candidate for cancers, metabolic diseases, and autoimmune disorders. However, recent studies demonstrated consecutive administration of celastrol at anticancer doses may induce severe heart injuries, which significantly limited its clinical translation. This study aimed to investigate the cellular target and potential mechanism underlying celastrol-induced cardiotoxicity. Consecutive i.p. injection of celastrol for 14 days induces cardiotoxicity in mice, as evidenced by reduced heart-to-body weight ratio, decreased cardiac output and stroke volume, and increased serum cardiac enzymes and proinflammatory cytokine levels in heart tissues. At the cellular level, celastrol triggered mitochondrial dysfunction and promoted cardiomyocyte apoptosis through activation of the mitochondrial pathway, as evidenced by altered B-Cell Lymphoma 2/Bcl-2-Associated X Protein (Bax/Bcl-2) ratio and expression of Cysteinyl aspartate specific proteinase 3 (caspase-3). Mechanistically, we identified Angiomotin-Like Protein 2 (AMOTL2) as a direct cellular target of celastrol using activity-based protein profiling (ABPP). Celastrol-AMOTL2 binding initiated a signaling cascade through Hippo pathway activation, promoting Yes-Associated Protein 1 (YAP1) phosphorylation and subsequent degradation. Knockdown of AMOTL2 by short hairpin RNA attenuated celastrol-induced cardiomyocyte apoptosis by enhancing YAP1 expression and mitochondrial biogenesis. These findings demonstrate that celastrol induces cardiotoxicity by directly targeting AMOTL2 and disrupting YAP1/PGC-1α/TFAM-dependent mitochondrial biogenesis.