Phospholipid transfer protein ameliorates sepsis-induced cardiac dysfunction through NLRP3 inflammasome inhibition

Cardiomyocyte pyroptosis is a primary contributor to sepsis-induced cardiac dysfunction (SICD). Recombinant phospholipid transfer protein (PLTP) have been demonstrated to possess anti-inflammatory and antiseptic properties. However, the effect of PLTP on SICD remains unknown. In this study, we established the in vivo and in vitro sepsis model with the recombinant PLTP treatment. The survival rates of mice, mouse cardiac function, cell viability, the protein level of proinflammatory cytokine, and lactate dehydrogenase level were evaluated. The cardiomyocyte pyroptotic changes were observed. The distribution of PLTP and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) in mouse myocardial tissue and expression of PLTP, apoptosis associated speck like protein containing a CARD (ASC), NLRP3, caspase-1, interleukin (IL)-1β, and Gasdermin D (GSDMD) were detected. PLTP ameliorated the cecal ligation and puncture-induced mouse survival rate decrease and cardiac dysfunction, inhibited the IL-1β, IL-18, and tumor necrosis factor (TNF)-α release, and blocked the NLRP3 inflammasome/GSDMD signaling pathway in septic mice. In vitro, PLTP reversed the lipopolysaccharide-induced cardiomyocyte pyroptosis, expression of IL-1β, IL-6, TNF-α, and activation of the NLRP3 inflammasome/GSDMD signal pathway. Moreover, PLTP could bind to NLRP3 and negatively regulate the activity of the NLRP3 inflammasome/GSDMD signal pathway. This study demonstrated that PLTP can ameliorate SICD by inhibiting inflammatory responses and cardiomyocyte pyroptosis by blocking the activation of the NLRP3 inflammasome/GSDMD signaling pathway.