Abstract Body: Background: Doxorubicin (DOX) is an effective chemotherapy but limited by severe cardiotoxicity. Chemokine receptors CXCR4 and CXCR7 are involved in regulating cardiac survival, inflammation, and fibrosis, yet their specific roles in DOX-induced cardiotoxicity (DICT) remain unclear.
Objective: We investigated the cardioprotective effects of TC14012, a dual-target CXCR4 antagonist and CXCR7 agonist, against DICT.
Methods: Male C57BL/6J mice received chronic or acute DOX administration with twice-weekly TC14012 treatment. Cardiac function was evaluated by echocardiography. Markers of cardiac fibrosis and inflammation were assessed. RNA-seq analysis was performed to explore associated molecular pathways. Key pathways were validated in cardiac cells and bone marrow-derived mast cells.
Results: TC14012 significantly improved cardiac function, indicated by preservation of ejection fraction and fractional shortening, and increased survival rates optimally at 5 mg/kg, which were accompanied with reductions in cardiac collagen deposition and infiltration of macrophages and neutrophils. RNA-seq revealed that TC14012 protecting against DICT was associated with a remarkable stimulation of signals involving in cardiac contraction and energy reserve metabolism processes, particularly glycogen and glucan metabolism that are crucial for meeting the cardiac energy demand in response to DOX induction. These signals could be further enriched into AMPK signalling pathway and validated by enhancement of cardiac AMPK phosphorylation both in vivo and in vitro. Meanwhile, TC14012’s cardioprotective effects were accompanied by a reduction in signals involving in cardiac mast cell activation and degranulation, which could be enriched into Rap1 signalling pathway and validated by TC14012 inhibiting mast cell activation and Rap1-GTP activity in vitro. Importantly, TC14012 did not compromise DOX’s antitumor efficacy in EL-4 lymphoma-bearing mice.
Conclusions: TC14012 may prevent DICT by activating CXCR7-AMPK signalling to reprogram cardiomyocyte metabolism and antagonizing CXCR4-Rap1 signalling to blunt mast cell-mediated sentinel effects without compromising the anticancer efficacy DOX.