Downregulated TRIM35 Alleviates Doxorubicin-Induced Cardiotoxicity by Suppressing Oxidative Stress and Inflammation via Inhibiting TLR4/NF-κB Pathway.

Purpose: The use of doxorubicin (DOX), a potent chemotherapy drug, is limited by its detrimental effects on the heart. This cardiotoxicity is primarily driven by oxidative stress and inflammation. TRIM35 plays a key role in inflammatory responses; however, its exact function in DOX-induced cardiotoxicity (DIC) remains to be fully understood. This study investigates the effects of TRIM35 on DIC and explores the underlying biological mechanisms.

Methods: To assess the role of TRIM35, we reduced the expression of TRIM35 in the heart tissues of mice using an adeno-associated virus 9 (AAV9) system, delivered through tail vein injection. We then administered weekly doses of DOX (4 mg/kg) to C57BL/6 mice for 4 weeks to induce DIC. Echocardiography, histopathological assessments, and molecular techniques were employed to examine the effects and mechanisms of TRIM35 on DIC.

Results: Our research found that DOX treatment increases TRIM35 levels in the heart. By lowering TRIM35 expression, we observed an improvement in cardiac function and a decrease in myocardial damage in DOX-treated mice. Additionally, reduced TRIM35 expression lessened myocardial hypertrophy and fibrosis. It also mitigated the oxidative stress and inflammation caused by DOX. Furthermore, the down-regulation of TRIM35 expression resulted in the downregulation of TLR4 and phosphorylated P65 expression.

Conclusion: Downregulated TRIM35 expression mitigates the oxidative stress and inflammation caused by DOX, likely through impacting the TLR4/NF-κB signaling pathway. These insights indicate that TRIM35 holds promise as a therapeutic target for managing heart damage induced by DOX.