PINK1-mediated mitophagy attenuates pathological cardiac hypertrophy by suppressing the mtDNA release-activated cGAS-STING pathway

Sterile inflammation is implicated in the development of heart failure (HF). Mitochondria play important roles in triggering and maintaining inflammation. Mitophagy is important for regulation of mitochondrial quality and maintenance of cardiac function under pressure overload. The association of mitophagy with inflammation in HF is largely unclear. As PINK1 is a central mediator of mitophagy, our objective was to investigate its involvement in cardiac hypertrophy, and the effect of PINK1-mediated mitophagy on cGAS-STING activation during cardiac hypertrophy.

PINK1 knockout and cardiac-specific PINK1-overexpressing transgenic mice were created and subsequently subjected to transverse aortic constriction (TAC) surgery. In order to explore whether PINK1 regulates STING-mediated inflammation during HF, PINK1/STING (stimulator of interferon genes) double-knockout (DKO) mice were created. Pressure overload was induced by TAC. Our findings indicate a significantly decline in PINK1 expression in TAC-induced hypertrophy. Cardiac hypertrophic stimuli caused the release of mitochondrial DNA (mtDNA) into the cytosol, activating the cGAS-STING signalling, which in turn initiated cardiac inflammation and promoted the progression of cardiac hypertrophy. PINK1 deficiency inhibited mitophagy activity, promoted mtDNA release, and then drove the overactivation of cGAS-STING signalling, exacerbating cardiac hypertrophy. Conversely, cardiac-specific PINK1 overexpression protected against hypertrophy thorough inhibition of the cGAS-STING signalling. DKO mice revealed that the effects of PINK1 on hypertrophy were dependent on STING.

Our findings suggest that PINK1-mediated mitophagy plays a protective role in pressure overload-induced cardiac hypertrophy via inhibiting the mtDNA-cGAS-STING pathway.