Expression And Significance Of Neuroglobin In Astrocytes After Ischemia Reperfusion

Stroke is the third largest fatal disease except cancer and cardiovascular disease,In our country, the incidence of the cases is about200million each year, which morethan80%is ischemic cerebral infarction. And there is no effective the reliabletreatments except early thrombolytic in clinically. The patients often leaving varyingdegrees of disabled sequelae after cerebral infarction. The patients not only have lowquality of life for themselves, but also cause great economic burden to their familiesand society. Neuroglobin(NGB) is the third globulin following the hemoglobin,myoglobin, possess the transport and storage of oxygen, widely distributed in variousregions of the brain tissue and peripheral nervous system. Astrocytes are the largestnumber of cells in the central nervous system, is the most powerful support cells forNeurons, playing an important role in maintain the stability of the internalenvironment, participate in the formation of the blood-brain barrier and nerveexcitability transfer. Activated astrocytes participate in the formation of glial scarringin cerebral ischemia, which hinder the repair and regeneration of damaged neurons inthe ischemic later. It has been reported that the presence of functional neuroglobin(NGB) in primary cultures of cerebral cortical astrocytes, NGB antisense treatmentincreased apoptosis in ischemic astrocytes. Therefore, to study the relationshipbetween neuroglobin and the proliferation of astrocytes in ischemia reperfusion issignificance for stroke treatment.The main purpose of this paper is to study the activation and proliferation of astrocytes in oxygen-glucose deprivation (OGD) and ischemia reperfusion (IR), tostudy the expression of NGB in astrocytes in OGD and reperfusion, at the same timeto study the relationship between NGB and C-RAF/MEK/ERK signal pathway. Inthis paper, we select oxygen and glucose deprivation (OGD) model in vitro simulationischemic and reperfusion in vivo. We culture primary SD rats astrocytes. We detectthe activation and proliferation of astrocytes in OGD and reperfusion though themethods of Immunofluorescence, EdU and PI stained; detect the expression of NGBin protein levels and mRNA levels in astrocytes in OGD and reperfusion though themethods of immunofluorescence and real-time reverse transcriptase polymerase chainreaction (real-time RT-PCR). Then C-RAF-1mutant plasmids and NGB plasmidsco-transfected in HEK-293T cells to study the relationship between NGB and RAF/MEK/ERK signal pathway. The results showed that astrocytes are activation andproliferation in OGD and reperfusion, the expression of NGB is increased in OGD4hr and reperfusion. The results showed the expression of NGB consistent with theproliferation of astrocytes in OGD and reperfusion. The results showed that NGB canactivate C-RAF-1to promote the activation of ERK1/2under normal condition. NGBmay affect other kinase activity leading to the activation of ERK1/2, or directlyactivate ERK1/2in ischemia.