Cardiac dysfunction is a common complication of sepsis, and is attributed to severe inflammatory responses. Ferroptosis is reported to be involved in sepsis-induced cardiac inflammation. Therefore, we speculated that ferrostatin-1 (Fer-1), a ferroptosis inhibitor, improves cardiac dysfunction caused by sepsis. An intraperitoneal injection of lipopolysaccharide (LPS) was performed to induce a rat cardiac dysfunction model. Echocardiography, cardiac histopathology, biochemical and western blot results were analyzed. Twelve hours after the LPS injection, LPS-treated rats exhibited deteriorating cardiac systolic function, increased levels of cardiac injury markers and levels of ferroptosis markers prostaglandin endoperoxide synthase 2 (PTGS2). Additionally, LPS increased iron deposition in the myocardium, with downregulating ferroportin (FPN, SLC40A1) and transferrin receptor (TfR)expression, and upregulating ferritin light chain (FTL) and ferritin heavy chain (FTH1) expression. Meanwhile, LPS also increased lipid peroxidation in the rat heart by decreasing the expression of glutathione peroxidase 4 (GPX4). Moreover, the expression of inflammatory cytokines, such as tumor necrosis-alpha (TNF-α), interleukin-1 (IL-1β), and interleukin-6 (IL-6), and inflammatory cell infiltration were also increased following LPS challenge. Finally, the abovementioned adverse effects of LPS were relieved by Fer-1 except for TfR expression. Mechanistically, Fer-1 significantly reduced the levels of toll-like receptor 4 (TLR4), phospho-nuclear factor kappa B (NF-κB), and phospho-inhibitor of kappa Bα (IκBα) in LPS-treated rats. In summary, these findings imply that Fer-1 improved sepsis-induced cardiac dysfunction at least partially via the TLR4/NF-κB signaling pathway.
Keywords: Ferroptosis; cardiac dysfunction; ferrostatin-1; inflammation.