Study On The Protective Effect And Mechanism Of PTP1B Specific Inhibitors On Cerebral Ischemia Repertusion Injury

Background:Secondary injury caused by cerebral ischemia reperfusion,has a huge impact on the recovery of neural function,how to clear concrete ways or cellular pathways by which ischemia-reperfusion functions in the process of nerve cell apoptosis,it would be helpful to improve the successful rate of such diseases and improve the function of the nervous system.And microglia,as a major immune effector cells of the nerve cells,has swallow,antigen presentation and expression and related with the immune system and inflammation factor,is bound to play an important role in the process of secondary injury and repair in CIRI,related studies have shown that the regulation effect of microglia activation on the release of inflammatory cytokines and neuronal apoptosis in CIRI,at the same time,microglia activation includes the enhancement of the stress in endoplasmic reticulum and innitiation of cell autophagy.PTP1B,as a kind of cell physiological function regulator in protein tyrosine phosphatase family,plays an important role in cell conduction pathway.Our research is carried out based on the microglia activation in CIRI,through the application of PTP1B inhibitors,study of PTP1B expression changes in microglia,the influence of inflammatory factors and apoptosis,and the changes of endoplasmic reticulum stress related proteins and the effects of cell autophagy protein,to clear whether PTP1B is fuctioned by endoplasmic reticulum stress and cell autophagy on the inflammatory response and apoptosis in microglia,applied theoretic evidence for the clinical application of specific medication towards CIRI caused secondary brain injury.Objectives:(1)By studying on the function of endoplasmic reticulum stress in the inflammatory response and apoptosis in microglia after cerebral ischemia reperfusion,to whether the application of selective PTP1B inhibitors sc-222227 can protect the nerve cells,to get whether the effect of nerve protection of specific PTP1B inhibitors function by the expression of endoplasmic reticulum stress related genes in microglia.(2)PTP1B intraventricular injection was used to treat animals with cerebral ischemia reperfusion injury to detect the activation of microglias;In addition,PTP1B inhibitors were used to treat microglias(BV-2 cell lines)cultured in vitro,and detect the changes in the expression of inflammatory factors to clarify that BV-2 cells treated with OGD could protect microglias with PTP1B inhibitors by inhibiting the expression of inflammatory factors.(3)Through the study about rat cortex endoplasmic reticulum stress related proteins(PERK,IRE-1,ATF6,etc.),to clear whether the PTPIB inhibitors treatment would have impact on the endoplasmic reticulum stress related proteins or not,and then,to study in which specific kinds of cells these proteins expressed,and whether it accordances with our previous two part of research of microglia,finally,by studying the mechanisms of the endoplasmic reticulum stress related autophagy protein(LC3-?/?,Beclin-1,etc.)after cerebral ischemia reperfusion injury in microglial cells,To clarify the neuroprotective role of PTP1B inhibitors in the treatment of cerebral ischemia reperfusion is by endoplasmic reticulum stress autophagy axis.Methods:This research established animal model of ischemia reperfusion in rats,applied PTP1B selective inhibitors treatment,and monitor inflammatory cytokines,cell apoptosis,endoplasmic reticulum stress response and cell autophagy proteins in CIRI by PCR,Western blot,immunofluorescence and immunohistochemical technique,and record changes in the rat neural function,detect the changes of cerebral infarction area and brain edema;on the other hand,by culturing OGD BV-2 cells in vitro,monitor inflammatory cytokines,cell apoptosis,endoplasmic reticulum stress response and cell autophagy proteins in CIRI by PCR,Western blot,immunofluorescence technique,and at the same time record function relationship to endoplasmic reticulum stress autophagy axis when use the PERK agonist,endoplasmic reticulum stress inhibitors and autophagy inhibitors.Finally,this study confirmed that PTP1B could play a series of downstream functions by interacting with p-PERK protein through PLA technology.Results:(1)PTP1B higher expressed in ischemia reperfusion injury in rats,apply the PTP1B selective inhibitors can effectively reduce the release of the inflammatory cytokines such as IL-1?,IL-6,TNF-a in ischemia-reperfusion in rats,reduce the apoptosis of neurons,meanwhile improve the area of the infarct rats,reduce the brain water content,improve nerve function and motor function in rats.(2)After ischemia reperfusion injury in rats,the expression of PTP1B protein in microglia was increased,and the application of PTP1B inhibitors could significantly improve the activity of microglia.In addition,the expression of inflammatory factors such as IL-1?,IL-6 and TNF-a was also significantly decreased after the intervention of PTP1B selective inhibitors with different concentrations on BV-2 cells treated with OGD in vitro.(3)PTP1B regulates the endoplasmic reticulum stress autophagy axis in microglia through PERK,thereby affecting the activation of microglia and regulating the expression of inflammatory factors,while autophagy of microglia is mediated by the PERK pathway of endoplasmic reticulum stress.Conclutions:After cerebral ischemia reperfusion injury,the expression of PTP1B in microglia enhanced,PTP1B inhibitors can regulate the endoplasmic reticulum stress autophagy signaling axis of microglia through the PERK pathway in microglia to protect neural function by the reduction of microglia activation,reduction of local inflammatory response and apoptosis of nerve cells.