Effect Of YL-PIA08 On The Activation Of Astrocytes And Neuronal Stress Injury After Brain Injury In Mice

Traumatic brain injury(TBI)is one of the main causes of morbidity and disability in children and adolescents,and it has severely affected public health,increased the economic burden on families and society,and has become a global health care problem,including China.Serious public health problem.At present,the central mechanism that causes emotional and behavioral obstacles is still not fully understood.In this study,intragastric administration of the translocator protein(TSPO)ligand YL-IPA08 of glial cell mitochondrial outer membrane transporter protein(TSPO)at different time periods after trauma was conducted to explore its effect on the activation of astrocytes(Astroglia,AG)and neuronal effects.Stimulate the impact of various biochemical indicators,and detect its impact on various indicators of motor function,mentality,working memory,and social interaction in mice after TBI.The aim is to provide a new idea for the prevention and treatment of secondary brain injury,so as to provide a theoretical basis for the prevention and treatment of brain injury.Method:Wild-type male C57BL/6 J mice were randomly divided into control group(CON),trauma group(TBI),trauma + saline group(TBI + SAL),trauma + acute gastric gavage group(TBI+YL#1),Trauma + chronic gastric gavage group(TBI+YL#2).Moderate brain injury is caused by hydraulic shock in the motor sensory area of mice.The TBI+YL#1 group was given YL-IPA08 by gavage during DPI1-DPI7,and the TBI+YL#2 group was given YL-IPA08 during DPI9-DPI55.After brain injury,select multiple time points to perform NSS,grid walking test,mine field test on mice to explore the effects of TBI and YL-IPA08 on the neurological and motor functions of mice;use tail suspension test,mine field test,The Y maze test,water maze test,three-chamber test and tube-dominant mouse test explore the effects of TBI and YL-IPA08 on depression,anxiety,learning,memory function,social interaction and aggression in mice.After the behavioral experiment,HE staining was used to observe the necrosis of cortical neurons.Immunofluorescence staining was performed to detect the number of positive cells in the brain tissue for related proteins,and semi-quantitative analysis was performed with Image J.Result:1.Weight testAfter mouse trauma modelling,the weight loss of mice in the TBI group and TBI+SAL group was significantly lower than that in the CON group(P <0.01).2.Behavioral testing(1)Neurofunctional score: The nerve scores of TBI,TBI+SAL,TBI+IPA08groups were significantly increased(p <0.01);while in the DPI8(P <0.05)and DPI55(P <0.05)tests,compared with the TBI+SAL group,intragastric administration The neurological score of mice in the group decreased significantly.(2)Grid test: In the two grid walk tests,the use rate of forelimb errors in the TBI and TBI+SAL groups was significantly higher than that in the CON group(p<0.01);compared with the TBI+SAL group,the forelimb errors in the DPI52 and YL-IPA08 groups The utilization rate was significantly reduced(P <0.05).(3)Aggressiveness test: After the mouse trauma model was established,the aggressiveness score of the mice in the trauma group decreased.The score of DPI4 was not significantly decreased(P> 0.05),and DPI52(P <0.05).The administration of YL-IPA08 can increase the aggressive advantage of mice(P <0.05).(4)Tail suspension test: The tail suspension time of mice in the trauma group was significantly higher than that in the CON group(DPI4,DPI52,p <0.01);compared with the TBI+SAL group,the effect of DPI4 and YL-IPA08 administration was not significant(P> 0.05),DPI52,after administration of YL-IPA08,the tail suspension time of mice was significantly shortened(p <0.01).(5)Open field test: Mice in the TBI group and TBI+SAL group had a significant decrease in the percentage of the total distance in the 25% area of the central grid after trauma(DPI5,DPI53,p <0.01).Compared with the TBI+SAL group,in the DPI5 test,the effect of YL-IPA08 administration was not significant(p> 0.05).In the DPI53 test,the percentage of the active distance in the 25% area of the central grid of the gavage group increased significantly(p <0.05).(6)Working memory test: The auto-rotation percentage and resolution coefficient of traumatized mice decreased significantly(p <0.01).Compared with the TBI+SAL group,the autorotation percentage of the mice in the gavage group increased significantly at DPI5(p <0.05)and DPI53(p <0.01).Administration of YL-IPA08 can significantly improve the resolution coefficient of mice at DPI5 and DPI53(p <0.01).In the water maze test at DPI55,the time for traumatized mice to find a platform was significantly increased(p <0.01),and the number of crossing the platform was significantly reduced(p <0.01).The mice in the YL-IPA08 group significantly shortened the time to find a platform(p <0.01)and increased the number of crossings(p <0.01).(7)Social ability test: After TBI,the social frequency and total social distance of mice were significantly reduced(p <0.01).The administration of YL-IPA08 had no significant effect at DPI7(p> 0.05),but at DPI55(p <0.01),it significantly increased the social frequency and total social distance of mice.Histological examinationThe cortical neurons of the mice in the TBI group and TBI+SAL group were arranged disorderly,accompanied by severe vacuoles and lysis.The cortical neurons in the CON group were arranged neatly with clear nucleoli.The morphology of neurons in the administration group was somewhere in between.In the TBI group and TBI+SAL group,the neurons in the damaged hippocampal DG area showed lysis,the neurons were in irregular clusters,and the nucleoli were indistinguishable.Immunofluorescence detection(1)Caprin1-SHH double-label detection: After TBI,the number of Caprin1 and SHH positive cells in the cortex and hippocampus DG area of the mouse injury test increased significantly(p <0.01).After administration of YL-IPA08,the Caprin1 protein in the cortex and hippocampus was reduced.The number of positive cells in the area(p <0.01),the number of positive cells in SHH increased(p <0.01).(2)Caprin1-NFH double-label detection: After brain injury,the number of Caprin1 and NFH positive cells in the cortex and hippocampus DG area of mice increased significantly(p <0.01).And the number of positive cells in the hippocampus(p <0.01).(3)C3-GFAP double-label detection: After brain injury,the number of C3 and GFAP positive cells in the cortex and hippocampus DG area of the mouse injury test increased significantly(p <0.01).After administration of YL-IPA08,C3 and GFAP were reduced in the cortex.And the number of positive cells in the hippocampus(p <0.01).(4)TSPO-GFAP double-label detection: After TBI,the number of TSPO and GFAP positive cells in the cortex and hippocampus DG area of the mouse injury test increased significantly(p <0.01).The number of positive cells in the hippocampus(p<0.01).Conclusion:Moderate TBI caused damage to the cortex and hippocampus neurons in mice;it caused a significant decline in neurological function,motor function,spatial cognitive ability,social interaction and aggressive advantage of mice,and showed significant depression and anxiety.Administration of YL-IPA08 after TBI can significantly improve motor function,spatial cognitive ability,learning and memory ability,social interaction and aggressive advantages of TBI mice,and reduce depression and anxiety in TBI mice.The above-mentioned neuroprotective effects of YL-IPA08 may partly lie in: reducing the activation of A1 type AG after TBI(the number of C3,GFAP-positive cells is reduced),mitochondrial damage in AG(the number of TSPO-positive cells is reduced),which may alleviate Neuroinflammation and oxidative stress in the brain;reduce neuronal stress damage(decrease in the number of NFH and Caprin1 positive cells);promote the proliferation of neural precursor cells and regulate reactive AG(increase in the number of SHH positive cells).