| Objective:Stress is a kind of non-specific defensive response.When it is too strong or prolonged,it will lead to different degrees of mental and psychological problems.At present,with the changes of social environment and lifestyle,mental disorders related to psychological stress have seriously affected people’s physical and mental health,and brought heavy burden to family and society.In judicial practice,cases of neuropsychiatric dysfunction caused by stress are also increasing.Due to the unknown pathogenesis and the lack of evaluation system,it brings difficulties and challenges to relevant judicial expertise.A large number of literatures have reported that stress can cause anxiety,depression and other emotional damage,and it is related to neurotransmitters,neuroinflammation,HPA axis and other factors.However,the specific mechanism is complex and has not been fully elucidated.It has been reported that the injury of myelin and oligodendrocyte occurred in some areas of the brain of patients with affective disorder.Proteomics analysis also confirmed that the differentially expressed proteins in the amygdala of psychological stress mice were enriched in myelin related components and functions,suggesting that psychological stress-induced affective disorders are related to amygdala myelin.We established a psychological stress mouse model by spectating electric shocks,and observed the changes in the expression of myelin-related proteins and oligodendrocytes in the amygdala of affective disorder mice,and administered clemastine to observe whether it could improve the affective disorder of mice,and to explore whether neuroinflammation was involved in the changes of myelin proteins in the amygdala.This study aims to clarify the mechanism of emotional damage caused by psychological stress from the perspective of myelin damage,and to provide new ideas for the intervention treatment of patients with related emotional disorders and the screening of evaluation indicators for related mental damage.Methods:In this study,8-week-old healthy C57BL/6J male mice were randomly divided into control group,psychological stress group,and psychological stress+clemastine group(10mg/kg).The mouse model of simple psychological stress was established by observing electric shock method,and the differential protein enrichment pathway was analyzed by proteomics.Behavioral methods such as sucrose preference test,elevated plus maze test,open field test and forced swimming test were used to observe the behavioral changes of mice,and the behavioral performance of improving myelin function by clemastine.Western Blot,ELISA,q PCR,immunofluorescence,transmission electron microscope and other molecular biological and morphological methods were used to study the expression of myelin related proteins MBP and PLP in the amygdala of mice;observe the expression of oligodendrocytes and their co-labeling with Brd U and Caspase-3;detect the expression of NLRP3,Caspase-1,ASC and IL-1βand TNF-αin the amygdala,as well as the expression and activity of microglia.Results:1.Compared with the control group,the sucrose preference test showed that the sucrose preference index of the psychological stress group was significantly decreased(P<0.001);The results of forced swimming showed that the immobility time of the psychological stress group was significantly prolonged(P<0.05).The results of open field test showed that the frequency of crossing the central area of the mice in the psychological stress group was significantly reduced(P<0.001).The elevated plus maze test showed that times spent in the open arms of the psychological stress group was significantly reduced(P<0.05).2.Proteomics results showed that the differentially expressed proteins in amygdala of psychological stress mice were enriched in myelin-related components and functions.The results of transmission electron microscopy showed that the myelin lamina of the control group was closely and regularly arranged.In stress mice,the myelin lamina was arranged disorderly and loosened,and the thickness of myelin sheath decreased.Compared with the control group,the Western-Blot results showed that the expression of MBP and PLP protein in the psychological stress group were decreased(P<0.01).The results of immunofluorescence staining showed that the number of oligodendrocyte precursor cell NG2~+(P<0.05),Olig2~+(P<0.05)and mature oligodendrocyte CC-1~+(P<0.05)in the amygdala of the psychological stress group were decreased.The number of NG2~+/Brd U~+(P<0.05),Olig2~+/Brd U~+cells(P<0.01)and CC-1~+/Brd U~+cells(P<0.01)were decreased.3.Compared with the stress group,the clemastine group showed a significant increase in sucrose preference(P<0.05)and a significant reduction in forced swimming immobility time(P<0.05).There was no significant difference in the number of crossing the central area in open field test(P>0.05)and the time spent in the open arms in elevated plus maze test(P>0.05).Western-Blot results showed that the expression of MBP and PLP protein in clemastine group was significantly increased(P>0.01).The results of immunofluorescence staining showed that the number of oligodendrocyte precursor cell NG2~+(P<0.05),Olig2~+(P<0.01)and mature oligodendrocyte CC-1~+(P<0.05)were increased in the clemastine group.There was no significant difference in the number of Caspase-3~+/CC-1~+cells(P>0.05).4.Compared with the control group,Western-Blot results showed that the expression of NLRP3 protein the mice in the psychological stress group was increased(P<0.05);ELISA results showed that the expression of IL-1β(P<0.001)and TNF-α(P<0.01)protein in the psychological stress group was increased.q PCR results showed that the m RNA expression of NLRP3 and Caspase-1 in the psychological stress group was increased(P<0.01).Immunofluorescence staining showed that the number of IBA-1~+/INOS~+cells in the amygdala was increased in the psychological stress group(P<0.001).Conclusion:1.Simple psychological stress induced emotional damage such as anxiety and depression in mice.2.Psychological stress caused by emotional disorders of the amygdala sheath damage in mice,reduce the proliferation and differentiation of the amygdala oligodendrocytes.3.Clemastine could reverse the depressive-like behavior of the psychologically stressed mice,but had no significant effect on the anxiety-like behavior.Clemastine can promote the proliferation and differentiation of oligodendrocytes and prevent the damage of amygdala myelin sheath induced by psychological stress,but it has no significant effect on the apoptosis of oligodendrocytes.4.Stress-induced amygdala myelin damage may be associated with neuroinflammation. |
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