The Influences Of The Necroptosis Inhibitor Necrostatin-1 On Endoplasmic Reticulum Stress After Spinal Cord Injury

Objective:To investigated whether necroptosis inhibitor Nce-1(Necrostatin-1)could mitigate Endoplasmic reticulum stress(ERS)after SCI and further explain the protective effect mechanism of Nec-1 after SCI.The research provide new measures for the treatment of SCI.Methods:Healthy Clean male 60 S-D rats weighing 0.25-0.30kg were randomized equally into four groups:the sham(? group,Sham group,n= 15),sham+Nec-1 treatment group(? group,Sham+Nec-1 group,n=15),SCI + Nec-1 treatment group(? group,SCI+Nec-1 group,n=15),SCI+Dimethyl Sulfoxide treatment goup(IVgroup,SCI group,n=15).Each group was divided three subgroups:6h?12h and 24h after SCI.And there are 3 S-D rats in subgroup of 6h and 6 S-D rats in subgroup of 12h and 24h.Allen's method was used to make rat acute spinal cord injury model.Nec-1 will be made into 25?g/?l solution;sham group(? group)without any treatment,? and? group injected 2u1 Nec-1 using a micro-syringe at 30 minute before SCI,?group injected the same amount of DMSO solution in the same time after injury.Giving penicillin to prevent infection,50,000U,rehydration when necessary.Postoperative bladder massage twice daily to help them urination until their micturition reflex restored.We used Real time fluorescent quantitative PCR and Reverse transcription PCR for detection of ERS related gene.Western blot(WB)and Immunofluorescence(IF)were used to detect ERS related protein expression level and location.Electron microscope was used to observation ultrastructure changes of endoplasmic reticulum and mitochondria.Results:The result of PCR show that ERS related gene CHOP mRNA,GRP78 mRNA and XBP1 mRNA expression level in SCI+Nec-1 group is significant lower than in SCI group(P<0.05).But there are no significant between sham and sham+Nec-lgoup.The research of WB find that three ERS related protein expression level in SCI group is higher than in SCI+Nec-1 group(P<0.05),but no significant between sham and sham+Nec-1 goup.While IF confirm that almost all ERS related protein is expression in nerve cell cytoplasm.The EM study show that administrate of Nec-1 could mitigate ultrastructure damage of endoplasmic reticulum and mitochondria after spinal cord injury.Conclusions:Necrostatin-1 could reduce endoplasmic reticulum stress related gene and protein expression level after acute spinal cord injury and it ease ultrastructure damage of endoplasmic reticulum and mitochondria after SCI.Inhibition of necroptosis after SCI provide a new strategy for the prevention and treatment of acute SCI.