Urolithin A attenuates Doxorubicin-induced cardiotoxicity by enhancing PINK1-regulated mitophagy via Ambra1.

Doxorubicin (Dox) is a widely used antineoplastics although its clinical usage is greatly limited by its cardiotoxicity. Several studies have depicted an essential role for dampened mitophagy and mitochondrial injury in Dox cardiotoxicity. However, preventative measure to alleviate Dox-evoked cardiotoxicity via targeting mitophagy and mitochondrial integrity remains elusive. Urolithin A (UA) is a newly identified mitophagy inducer with antioxidant and anti-apoptotic properties although its effect on Dox-induced cardiotoxicity is unknown. This study was designed to explore the effect of UA on Dox cardiotoxicity and mechanisms involved. Our results indicated that UA alleviated Dox-induced cardiac dysfunction exhibited by echocardiographic parameters and histological analyses, and partially relieved Dox-induced apoptosis in vitro and in vivo, and mitochondrial dysfunction including ΔΨm dissipation and ROS production in vitro. The ability of UA to facilitate restoration of mitophagy in mice and H9C2s underscored its advantageous effects, manifested as upregulation of mitophagy-related proteins, including p62, LC3, PINK1 and Parkin, as well as the co-location between LC3 and mitochondria. Incubation with 3MA nearly reversed the UA-evoked rise of mitophagy-related proteins, and inhibition of apoptosis. Given that knockdown of Ambra1 almost abolished UA-induced protective effect, the enhanced expression of Ambra1 owing to UA increased PINK1 levels by inhibiting its degradation via LONP1. Collectively, our results suggest that the cardioprotective properties of UA depend on the stimulation of PINK1-dependent mitophagy through promoting Ambra1 expression to inhibit PINK1 degradation by LONP1. This highlights UA's potential as a valuable treatment option and its importance in cardioprotective strategies against Dox-induced cardiotoxicity.