GI‐Y2, a novel gasdermin D inhibitor, attenuates sepsis‐induced myocardial dysfunction by inhibiting gasdermin D‐mediated pyroptosis in macrophages

BACKGROUND AND PURPOSE: Myocardial dysfunction is a significant complication associated with sepsis. However, there are currently no specific and effective treatments available. Inhibiting gasdermin D (GSDMD)-mediated pyroptosis has shown promise in mitigating sepsis-induced myocardial dysfunction. The GSDMD inhibitor Y2 (GI-Y2) has been demonstrated to directly bind to GSDMD. Nonetheless, it remains uncertain whether GI-Y2 offers a cardioprotective effect in the context of sepsis-induced myocardial dysfunction. EXPERIMENTAL APPROACH: A mouse model of sepsis was created using lipopolysaccharide (LPS), caecal ligation and puncture. Following treatment with GI-Y2 or macrophage membrane-encapsulated GI-Y2 nanoparticles (GI-Y2@MM-NPs), myocardial dysfunction and pyroptosis levels in heart tissues were assessed. Transcriptome sequencing revealed the molecular mechanism of GI-Y2 in treating septic cardiomyopathy. KEY RESULTS: We observed that GI-Y2 alleviated myocardial dysfunction and attenuated cardiac inflammation in mice induced by LPS, caecal ligation and puncture. GI-Y2 reduced macrophage pyroptosis and attenuated macrophage-mediated cardiomyocyte injury induced by LPS/nigericin. Concurrently, we confirmed the protective effect of GI-Y2 against LPS-induced cardiac dysfunction was abolished in the absence of GSDMD. Additionally, GI-Y2 attenuated the mitochondrial damage induced by LPS by inhibiting GSDMD in the mitochondria. Furthermore, we developed GI-Y2@MM-NPs to enhance the targeting capability of GI-Y2 towards macrophages in heart tissues and demonstrated its protective effect in vivo. CONCLUSION AND IMPLICATIONS: These findings indicate that GI-Y2 alleviates septic myocardial injury and dysfunction by specifically targeting GSDMD, thereby inhibiting GSDMD-mediated pyroptosis and mitochondrial damage. Both GI-Y2 and GI-Y2@MM-NPs may serve as promising therapeutic options for addressing septic myocardial dysfunction.