The Mechanism And Effects Of Notch Signalling Pathway On Ischemic Brain Injury

Ischemic cerebrovascular disease is clinically the most common neurologicaldiseaseswith high morbidity and highmortality rate, therefore, the mechanism of ischemicbrain injury study will cerebrovascular disease is important to prevent. In recent years, signaltransduction in the nervous system diseases occur, the development of the researchhasreceived extensive attention, the Notch pathway is involved in the mechanism ofischemicbrain damage is more and more attention, Studies have shown that Notch signalingregulation of arterial generated involved in ischemic brain injury.Notch signaling is a highly conserved during evolution, signal transductionpathwaysexist in multiple species of invertebrates and vertebrates, determining cell fate intheorganism during development, the Notch signal transduction pathway throughthenextsecretion acting on neighboring cells, neurons, indirect regulation of vascularendothelial cells during development, cell differentiation, which regulate cell proliferation,differentiation and apoptosis functions involved in almost all tissues and organs, but Notchsignaling is involved in ischemic brain injury processits mechanism is not clear-depth studyof the effect and mechanism of the Notch signaling pathway incerebral ischemic injury, tofurther reveal the contact and the internal mechanism ofNotch signal transduction pathwayand cerebral ischemic injury, may be cerebral ischemic injuryof treatment to provide atheoretical basis. In this study, the innovationlies in the fact that the first in vitro experimentsto explore its molecular mechanism ofNotch signaling in cerebral ischemic injury in earlyexperimental basis, the findings forthe mechanism of the Notch signaling pathway incerebral ischemic injury in show that the Notch signaling pathway may become a new targetfor research and early treatmentof cerebral ischemic injury of cerebral ischemic injurymechanism..1. OGD induces neural ischemia tolerance in PC12cellsObjective: PC12cell was used to set up a ischemia model by OGD.Methods: NGF and OGD were used to stimulate PC12cells and to establish anischemia model.2. The MTT analysis, real time PCR and western blotting analysis were usedto identity the oxygen glucose deprivation model. Results: The application of a final concentration of50ng/ml of NGF in DMEMcomplete mediumPC12cells showed a typical neuronal morphology with the increase in cellculture time.MAP2immune fluorescence cell chemical staining was strongly positive; withculture time to increase the expression of MAP2of increased gradually, and NGF culturetimeshowed a positive correlation, the establishment of oxygen and glucosedeprivation(OGD) training environment, the OGD after nerve element appears differentdegrees of damage, necrosis and apoptosis and prolong survival with OGD timedecreased,increased apoptosis rate. OGD can effectively induce the expression of HSP70.Conclusion: PC12cell transformed into cells by NGF;The cell model of OGD wasestablished.2. The expreesion of Notch signaling pathway in oxygen glucose deprivation modelObjective: The expression of Notch pathway in OGD model.Methods: The real time PCR and western blotting analysis were used to identity theexpression of Notch1, Hes1and Hes5.Results: After OGD, Notch1, of Hes1and Hes5expression significantly upregulated,and at each time point were higher than, OGD3h after this three level of gene expression,the latter gradually decreased with time.Conclusion: OGD can up-regulate the Notch signaling pathway, important sites ofNotch1, of Hes1and of Hes5mRNA and proteinlevels,and with OGD time to extendthedynamic changes; the OGD can activate the Notch signaling pathway.3. The effect of block Notch signaling pathway in OGDObjective: To study the effect of Notch pathway in OGDMethods: MTT and flow cytometry were used to detect the effects of block Notchsignaling pathway on proliferation and apoptosis inxygen glucose deprivation model;Hoechst staining was used to detect the cellular morphology.Results:Notch pathway activation agent caneffectively increase a expression ofNotch1mRNA,increase in the expression of Notch1protein; Notch signaling pathwayblockers can beeffective to inhibition Notch1mRNA and protein expression. Notch blockergroupcompared to the cell survival of PC12the OGD3h group has increased; ofNotchactivator group of PC12the OGD3h group compared to the cell viability declined.Hoechst staining Notch pathway activator group increased apoptotic cells compared with theOGD3h group, uneven distribution of chromatin, nuclear condensation, nuclearstain; ofNotch pathway blocker group of apoptotic cells decreased, the nuclear membrane integrity, nuclear oval shape, chromatin distribution..Conclusion: Notch signal transduction pathway activator can effectively activate theNotch signalingpathway; of Notch signal transduction pathway blockers can effectivelyinhibit theactivation of the Notch signal transduction pathway; of Notch signalingpathway in theregulation of cerebral ischemic injury in the process ofplay a negative role inapoptosis.4. The mechanisms of block Notch signaling pathway in OGDObjective: To study the mechanism of Notch pathway in OGDMethods: The real time PCR and western blotting analysis were used to study theexpression of Bcl-2,Bax in the blocking Notch signaling pathway.Results: Blocking Notch signaling pathway, in OGD3h, cells Bcl-2mRNA andprotein expression was significantly decreased; Bax mRNA and protein expression wassignificantly increased; decreased of Bcl-2/Bax ratio.Conclusion: The ischemic brain injury early can activate the Notch signaling pathwayand plays a negative role in the regulation of apoptosis, its mechanism may beloweredapoptosis suppressor proteinBcl-2expression, increase of the proapoptotic proteinBaxexpression.