Activation Of PPARγ Inhibits Ferroptosis Injury In Epileptic Rats Through The Nrf2-Gpx4 Signaling Pathway

Objective:Epilepsy is one of the most common chronic central nervous system diseases,and its pathophysiological mechanism has not been fully elucidated.Ferroptosis,as a novel cell death mode caused by accumulation of iron-dependent lipid peroxides,has been confirmed to be involved in the pathophysiological process of epilepsy and is expected to be a new target for the treatment of epilepsy.Peroxisome proliferation activated receptors(PPARγ)and Nuclear factor E2-related factor 2(Nrf2)are two important antioxidant transcription factors,which can regulate each other and synergically inhibit lipid peroxidation in cells.Glutathione peroxidase 4(Gpx4)is the downstream target gene of Nrf2.It is the most important intracellular antioxidant enzyme.The lipid reactive oxygen species,lipid reactive oxygen species,The accumulation of L-ROS inhibits the occurrence of ferroptosis.In conclusion,the purpose of this study was to investigate whether the activation of PPARγ can inhibit ferroptosis in epileptic rats induced by lithium chlorine-pilpiline through Nrf2-Gpx4 signaling pathway,so as to explore new drug targets for the treatment of epilepsy.Methods:There were 60 healthy male wistar rats,9 were randomly selected as Normal saline(NS)group,and Status Epilepticus(SE)was induced by lithium chloride-pilocarpine in the remaining rats.The SE rats were randomly divided into three groups: Epilepsy model group(EP),PPARγ activator group(Rosiglitazone RSG),and PPARγ inhibitor group(T0070907).NS group and EP group were injected intraperitoneally with equal volume of normal saline simultaneously,RSG group and T0070907 group were injected intraperitoneally with RSG(10 mg/kg)and T0070907(2 mg/kg),respectively.After treatment,24-hour video monitoring was used to detect the frequency and severity of Recurrent spontaneous seizures(SRSs)after 14 days.Finally,the remaining 9 rats in EP group,RSG group and T0070907 group showed SRSs,which could be used for follow-up experiments.Colorimetry was used to detect the content of ferroptosis biomarkers(Fe2+,GSH,MDA)in the hippocampus of rats.mRNA and protein expression levels of PPARγ,Nrf2,Gpx4 in the hippocampus of rats were detected by RT-PCR and WB.Results:(1)The 24-hour video monitoring results showed that RSG treatment decreased the frequency and grade of SRSs in epileptic rats compared with EP group(P < 0.05),while T0070907 increased the frequency and grade of SRSs in epileptic rats(P < 0.05).(2)Colorimetric results showed that compared with NS group,the contents of anti-iron death factor GSH in EP group were decreased,while the contents of fe-promoting death factor Fe2+ and lipid peroxidation product MDA were increased(P < 0.05).Compared with EP group,GSH content in RSG group was increased,while Fe2+ and MDA contents were decreased(P < 0.05).The contents of GSH in T0070907 group were decreased,while the contents of Fe2+ and MDA were increased(P < 0.05).(3)RT-PCR results showed that compared with NS group,the mRNA expressions of antioxidant factors PPARγ and Nrf2 in EP group were increased,and the mRNA expressions of iron death regulator Gpx4 were decreased(P < 0.05).Compared with EP group,the mRNA expression levels of Nrf2 and Gpx4 in RSG group were increased(P < 0.05),while those in T0070907 group were decreased(P < 0.05).(4)WB results showed that compared with NS group,the protein expressions of antioxidant factors PPARγ and Nrf2 in EP group were increased,and the protein expressions of iron death regulator Gpx4 were decreased(P < 0.05).Compared with EP group,the protein expression levels of Nrf2 and Gpx4 in RSG group were increased(P < 0.05),while the protein expression levels of Nrf2 and Gpx4 in T0070907 group were decreased(P <0.05).Conclusion:The results show that ferroptosis is involved in the pathophysiological process of epilepsy,and activation of PPARγ can inhibit ferroptosis in epileptic rat models through Nrf2-Gpx4 signaling pathway and play a neuroprotective role.