Inhibition of Spi1 alleviates doxorubicin-induced myocardial injury by suppressing YTHDF2-mediated PI3K/AKT/mTOR signaling

Cardiovascular diseases have long posed a significant threat to public health. Among them, myocarditis is a major category of cardiovascular disorders that is characterized by high mortality during its acute phase, necessitating urgent medical attention. This study aims to explore the therapeutic effects and underlying mechanisms of Spi1-mediated gene regulation in chemotherapy induced cardiomyopathy. To validate our findings, we employed bioinformatics analysis methods and established myocarditis models using the chemotherapeutic drug doxorubicin in both cellular and animal models. Our results demonstrated that the inhibition of Spi1 significantly suppressed inflammatory factor expression in H9C2 rat cardiomyocytes. Furthermore, in C57BL/6 mouse model, Spi1 inhibition was shown to improve cardiac function and alleviate both myocardial inflammation and fibrosis in mice with doxorubicin-induced myocarditis. Mechanistic investigations revealed that Spi1 suppression altered the expression of genes associated with immune response, cell differentiation and proliferation. Notably, Spi1 modulates the expression of YTHDF2, thereby influencing the PI3K/AKT/mTOR signaling pathway and subsequently regulating the inflammatory response. Collectively, these findings suggest that Spi1 plays a pivotal role in doxorubicin-induced myocarditis by mitigating inflammatory responses and myocardial injury through the regulation of YTHDF2 and the PI3K/AKT/mTOR signaling pathways, offering a promising therapeutic target for the treatment of myocarditis.