The Cardiac Endothelial Cell cGAS-STING Pathway Promotes Doxorubicin-Induced Cardiotoxicity via CD38-Mediated NAD Decline and Mitochondrial Dysfunction [mouse]

Doxorubicin is an effective chemotherapy drug for treating various types of cancer. However, lethal cardiotoxicity severely limits its clinical use. Recent evidence has indicated that aberrant activation of the cytosolic DNA-sensing cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway plays a critical role in cardiovascular destruction. Here, we investigate the involvement of this mechanism in doxorubicin-induced cardiotoxicity (DIC). Mice were treated with low-dose doxorubicin to induce chronic DIC. The role of the cGAS-STING pathway in DIC was evaluated in cGAS-deficiency (cGAS-/-), Sting-deficiency (Sting-/-), and interferon regulatory factor 3 (Irf3)-deficiency (Irf3-/-) mice. Endothelial cell (EC)-specific conditional Sting-deficiency (Stingflox/flox/Cdh5-CreERT) mice were used to assess the importance of this pathway in ECs during DIC. We also examined the direct effects of the cGAS-STING pathway on nicotinamide adenine dinucleotide (NAD) homeostasis in vitro and in vivo.