Pericytes Activation And Participanting Peripheral Glial Scar Formation In Rat Hippocampus After Epileptic Status

Objective:Cerebrovascular dysfunction and hippocampal sclerosis often occur in experimental epilepsy and human epilepsy.Pericytes are considered to be a component of scar formation after central nervous system injury.However,previous studies have mostly focused on astrocytes,and the mechanism of pericytes is still unclear.It is important for elucidating the mechanism of scar formation after central nervous system injury to understand the perivascular activation of reactive pericytes after status epilepticus,and explore the proliferation and functional relationship between NG2~+pericytes and GFAP~+glial cells.Methods:The status epilepticus model was induced with young SD rat,and the rats was divided into group SE1d,SE3d,SE7d,SE28d.Untreated rats belong to control group.The open field test was used to observe the behavioral changes,and HE was performed to observe basic pathological changes.Ultrastructural changes are observed by electron microscope.Use immunohistochemistry,immunofluorescence and Western blot to detect expression of NG2 and GFAP,and use immunofluorescence technology to double stain NG2 and GFAP to observe their relationship.Results:The open field test showed that the total distance and speed of the SE group increased significantly.SE rats had excessive activity.In the experimental group,the neurons were arranged disorderly,losing the ribbon structure.There were more glial cells proliferation.Compared with the control group,it was found that NG2 and GFAP showed a dynamic high expression after SE(P<0.05),and the number of pericytes and astrocytes increased significantly,respectively reaching a peak at 7d and 3d.The results of Western blot were in accord with histochemistry and immunofluorescence.The aggregation of pericytes and glial cells are induced in the surrounding area,forming a pericapillary multicellular scar.Conclusion:Our research showed that at different stages after SE,the expression of hippocampal pericytes increased.At the same time,GFAP+astrocytes proliferated and gathered around vessels and NG2+pericytes,showing the state of astrocyte scarring.Both pericytes and astrocytes were involved in glial scarring providing a new target for future anti-glial scar therapy.