NINJ1 Aggravates Doxorubicin-Induced Cardiotoxicity by Suppressing AMPK-Mediated HIF-1α Deubiquitination

Aims: Doxorubicin (DOX) remains a cornerstone of cancer therapy but is limited by dose-dependent cardiotoxicity with inadequate protective strategies. Nerve injury-induced protein 1 (NINJ1), a regulator of inflammation and cell death, has not been explored in this context. We sought to define the role of NINJ1 in DOX-induced cardiotoxicity and evaluate its translational potential. Results: Using complementary genetic, pharmacologic, and transcriptomic approaches, we demonstrate that NINJ1 is markedly upregulated in DOX-treated murine hearts and cardiomyocytes. Cardiomyocyte-specific NINJ1 deletion confers robust protection against cardiac dysfunction, oxidative stress, and apoptosis, whereas NINJ1 overexpression exacerbates injury. Mechanistically, NINJ1 suppresses AMP-activated protein kinase (AMPK) activation, promoting ubiquitin-mediated degradation of hypoxia-inducible factor-1α (HIF-1α), thereby impairing antioxidant gene programs. Multilevel evidence, including RNA sequencing, pathway enrichment, and gain- and loss-of-function models, establishes the NINJ1-AMPK-HIF-1α axis as a central regulator of redox homeostasis. Pharmacologic inhibition of NINJ1 with phenyl-β-D-glucopyranoside attenuates cardiac injury in vivo and in vitro without compromising DOX antitumor efficacy, supporting pathway specificity and therapeutic feasibility. Innovation: This study identifies NINJ1 as a previously unrecognized driver of anthracycline cardiotoxicity and uncovers a novel signaling axis linking membrane injury signaling to metabolic control of HIF-1α stability. Conclusions: NINJ1 promotes DOX-induced cardiotoxicity by destabilizing HIF-1α via AMPK inhibition. Targeting NINJ1 represents a promising cardioprotective strategy. Clinical Significance: Therapeutic inhibition of NINJ1 protects the heart while preserving anticancer efficacy, offering a potential strategy to enhance the safety of anthracycline-based chemotherapy and improve outcomes in cancer patients. Antioxid. Redox Signal. 00, 000–000.