The Role And Mechanism Of Ferroptosis In The Cardiotoxicity Of T-2 Toxin

Object: T-2 toxin is an environmental contaminant widely found in food crops,which harms several organs of the body,such as brain,liver,kidney,and heart,etc.T-2 toxin can induce severe cardiotoxicity,causing cardiac histopathy and impairing myocardial function,etc.,which deserves extensive attention.T-2 toxin causes cardiotoxicity by inducing oxidative stress,which eventually causes cardiomyocyte death,including apoptosis and autophagy.Iron death is a novel iron-dependent cell death mode discovered in recent years,but iron death has not been reported in T-2 toxin-induced myocardial injury so far.Heme oxygenase-1(HO-1)is a rate-limiting enzyme that catalyzes the conversion of heme and is involved in the regulation of various cell death modes,including iron death,and plays an important role in the regulation of iron death by mitigating oxidative damage through its antioxidant effect.In this study,we focused on the role of iron death in T-2toxin-induced myocardial toxicity and the regulatory mechanism of HO-1 in T-2 toxininduced myocardial iron death.Methods: Fifty C57BL/6 mice were randomly divided into solvent control group(0.5%DMSO),T-2 toxin low dose group(3 mg/kg T-2),T-2 toxin high dose group(5 mg/kg T-2),iron death inhibitor group(10 mg/kg liproxstatin-1),T-2 toxin + iron death inhibitor group(10 mg/kg liproxstatin-1 + 3 mg/kg T-2),and 10 mice in each group.+T-2 toxin was given by gavage,and the iron inhibitor Liproxstatin-1 was injected intraperitoneally 2 h before the administration of T-2 toxin.After 24 h of toxicity,blood and heart tissues were collected,and serum levels of cardiac troponin i(c Tn-1),creatine kinase mb isoenzyme(CK-MB),and serum iron were measured,and heart tissues contained ROS,divalent iron,malondialdehyde,and reduced glutathione(GSH).Glutathione(GSH)to oxidized lutathione(GSSG)ratio,as well as oxidative stress and iron death pathway related molecules glutathione peroxidase 4(GPX4),Ferritin heavy chain(FTH1)were expressed.In vitro assays were performed on human-derived cardiomyocytes(AC16)at different doses of T-2 toxin(0-80 ng/ml)for 24 h.Cytotoxicity,including cell survival,lactate dehydrogenase(LDH)leakage rate,ATP content,ROS production,cellular iron and ferritin heavy chain(FTH1)were measured after T-2 toxin transfection at doses of 0,2.5 and 5ng/ml.The results showed that ATP content,ROS production,cellular iron,GSH and MDA content,and gene and protein expression of oxidative stress and iron death related molecules HO-1,GPX4 and FTH1 were measured.The above indexes were observed after pretreatment with the iron death inhibitor liproxstatin-1(1 μM)for 24 hours and the HO-1 specific inhibitor tin protoporphyrin(Snpp)at 10 μM for 1 hour before T-2 toxin staining.Results: After 24 h of administration to mice,T-2 toxin dose-dependently caused elevated serum c Tn-1,CK-MB and serum iron levels,increased ROS,elevated iron and MDA levels in heart tissue,decreased GSH/GSSG,and down-regulated m RNA and protein expression of GPX4 and FTH1 and increased m RNA levels of Ptgs2 compared to controls.t-2 toxin in a dose-T-2 toxin decreased cell viability,ATP content and GSH/GSSG ratio,increased cellular iron and MDA content,and downregulated m RNA and protein expression of HO-1,GPX4,and FTH1 in a dose-dependent manner in AC16 cells.Iron death inhibitor Liproxstatin-1 administration alleviated the ex vivo cardiotoxic response induced by T-2toxin.HO-1 inhibitor Snpp worsened the toxic effects of T-2 toxin on AC16 cells.Conclusion:T-2 toxin can cause cardiac oxidative damage and myocardial ferroptosis,and inhibits HO-1 signaling molecules,and HO-1 inhibition can further increase the cardiotoxicity of T-2 toxin.