Mitochondrial DNA (mtDNA) is a potent agonist of the innate immune system; however, the exact immunostimulatory features of mtDNA and the kinetics of detection by cytosolic nucleic acid sensors remain poorly defined. Here, we show that mitochondrial genome instability promotes Z-form DNA accumulation. Z-DNA binding protein 1 (ZBP1) stabilizes Z-form mtDNA and nucleates a cytosolic complex containing cGAS, RIPK1, and RIPK3 to sustain STAT1 phosphorylation and type I interferon (IFN-I) signaling. Elevated Z-form mtDNA, ZBP1 expression, and IFN-I signaling are observed in cardiomyocytes after exposure to Doxorubicin, a first-line chemotherapeutic agent that induces frequent cardiotoxicity in cancer patients. Strikingly, mice lacking ZBP1 or IFN-I signaling are protected from Doxorubicin-induced cardiotoxicity. Our findings reveal ZBP1 as a cooperative partner for cGAS that sustains IFN-I responses to mitochondrial genome instability and highlight ZBP1 as a potential target in heart failure and other disorders where mtDNA stress contributes to interferon-related pathology.

线粒体 DNA (mtDNA) 是先天免疫系统的有效激动剂；然而，mtDNA 的确切免疫刺激特征和胞质核酸传感器的检测动力学仍不清楚。在这里，我们发现线粒体基因组的不稳定性促进了 Z 型 DNA 的积累。 Z-DNA 结合蛋白 1 (ZBP1) 可稳定 Z 型 mtDNA，并使含有 cGAS、RIPK1 和 RIPK3 的胞质复合物成核，以维持 STAT1 磷酸化和 I 型干扰素 (IFN-I) 信号传导。接触多柔比星后，心肌细胞中的 Z 型 mtDNA、ZBP1 表达和 IFN-I 信号传导升高，多柔比星是一种一线化疗药物，可在癌症患者中引起频繁的心脏毒性。引人注目的是，缺乏 ZBP1 或 IFN-I 信号传导的小鼠可以免受阿霉素诱导的心脏毒性。我们的研究结果表明，ZBP1 作为 cGAS 的合作伙伴，维持 IFN-I 对线粒体基因组不稳定性的反应，并强调 ZBP1 作为心力衰竭和其他 mtDNA 应激导致干扰素相关病理的疾病的潜在靶标。