NLRP3 inflammasome regulates doxorubicin-induced cardiotoxicity by modulating the abundance of gut microbiota

Doxorubicin (DOX) is a widely used anthracycline whose dose-dependent cardiotoxicity limits its clinical efficacy. However, the mechanisms underlying its toxicity, particularly the regulatory network involving the Nod-like receptor protein 3 (NLRP3) inflammasome-gut-heart axis, remain incompletely understood. This study aimed to establish cellular and animal models of doxorubicin-induced cardiotoxicity (DIC) and investigate the role of the inflammasome in DIC-associated alterations in gut microbiota abundance. Rat cardiomyocytes (H9c2 cells) were treated with DOX 1, 10, 25, and 50 μmol/L concentrations to assess dose-dependent cardiotoxicity. In vivo, C57BL/6 J and NLRP3/MLKL/RIPK3 knockout (KO) mice received DOX (5 mg/kg, intravenous, every 2 days for 3 doses, cumulative 15 mg/kg) to establish a DIC model. We measured the physiological and biochemical parameters of mice peripheral blood using an automatic biochemical analyzer. Additionally, we quantified the mRNA expression levels of inflammatory factors using a reverse transcription polymerase chain reaction and observed cardiomyocyte apoptosis. Fecal samples were collected from each group for 16S recombinant DNA sequencing to analyze gut microbiota. DOX-induced H9c2 cell damage and inflammatory factor release activated the NLRP3 inflammasome and upregulated autophagy-associated proteins LC3I/II. NLRP3 KO attenuated DOX-induced cardiac damage, modulated the immune environment in mouse blood, and mitigated DIC. NLRP3 KO lowered the abundance of mucinophilic Akkermansia muciniphila and suppressed the cardiotoxic effects of DOX. The cardiotoxic effects of DOX were mediated via the NLRP3 inflammasome. NLRP3 inflammasome may mediate DIC by regulating the abundance of gut Akkermansia muciniphila.