Targeting the Apelin-APJ Axis: A Promising Strategy to Mitigate Anthracycline-Induced Cardiotoxicity.

Anthracycline-induced cardiotoxicity remains a major clinical challenge, often progressing to heart failure years after therapy. Conventional cardioprotective agents, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and beta-blockers, are widely used to preserve cardiac function; however, their effectiveness is limited by their inability to comprehensively address the complex, multifactorial pathophysiology of anthracycline-induced cardiotoxicity. This underscores the critical need for more effective and mechanism-based cardioprotective strategies that directly target the underlying molecular mechanisms, particularly oxidative stress and mitochondrial dysfunction. In recent years, the apelin-APJ signalling axis has attracted increasing attention as a potential therapeutic target in cardiovascular diseases owing to its multifaceted biological actions, including positive inotropy, vasodilation, anti-inflammatory, anti-fibrotic, anti-apoptotic, antioxidant, and pro-angiogenic effects. These pleiotropic actions are primarily mediated through the activation of key signalling pathways such as phosphoinositide 3-kinase/protein kinase B, extracellular signal-regulated kinases 1/2, and AMP-activated protein kinase. Given that these signalling cascades are disrupted during anthracycline-induced cardiotoxicity, pharmacological activation of the apelin-APJ axis may represent a promising avenue to mitigate anthracycline-associated cardiac injury with greater efficacy than conventional therapies. While native apelin isoforms (apelin-12, -13, -17, and [Pyr¹]apelin-13) are limited by their short half-lives, chemically modified analogues such as LIT01-196 and apelin-17(A2) exhibit enhanced stability and efficacy, with demonstrated cardioprotective effects in preclinical cardiovascular models and patients with chronic heart failure. However, their therapeutic potential in anthracycline-induced cardiotoxicity remains largely unexplored. This review highlights its promise as a novel cardioprotective strategy for mitigating anthracycline-induced cardiotoxicity.