Sex Effect On Cardiac Damage And Gut Microbiota In EAE

Multiple sclerosis(MS)is a chronic autoimmune disease of the central nervous system.Recent clinical study suggested that MS patient exhibited acute heart failure.Further,12-lead electrocardiographic study showed a longer QTc interval in both MS patient and experimental autoimmune encephalomyelitis(EAE)Lewis rat.However,there is limited study regarding the effect of sex on cardiac injury in EAE.To our knowledge,sex effect on cardiac damage in mice with EAE has not yet been published.Herein,we examined the role of the immune system in mediating cardiac dysfunction after EAE in female and male mice.EAE induced severe neurology deficit by neurological function test every two days.In addition,EAE exhibited severe demyelination of central nervous system by immunoflurescence staining(MBP)of brain tissue coronal sections and western blot of MBP.Meanwhile EAE induced severe cognitive function deficits by Morris water maze test and novel odor cognition test,and male EAE exhibited more severe cognitive deficit than femal at second month after immunization in novel odor cognition test.Cardiac function was assessed by echocardiography at first month and second month after EAE induction.EAE mice exhibited severe cardiac dysfunction,including decreased left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS)at first and second month after EAE induction.Meanwhile male EAE presented increased expression of the oxidative stress(e.g.,nicotinamaide adenine dinucleotide phosphate oxidase-2;NOX-2)in immunofluorescence staining of heart coronary section,as well as cardiac hypertrophy(the value of heart weight to tibia length and H&E staining of cardiac coronary section),increased left ventricle(LV)mass(assessed by echocardiography)and more severe cardiac fibrosis(PSR staining of cardiac coronary section)compared with male control mice.In addition,male EAE mice showed significantly increased cardiac canonical inflammatory mediator(e.g.,monocyte chemoattractant protein-1;MCP-1,transforming growth factor-β;TGF-β and toll-like receptor 2;TLR-2)by immunofluorescence staining of cardiac coronary section compared with female EAE mice at second month after EAE induction.In addition,the counts of leukocytes and neutrophils were significant increased in female and male EAE mice heart by flow cytometry compared with female and male control mice,respectively.However,there was no significant statistic difference between female EAE male EAE.The number of macrophages was significantly increased in male EAE compared with male control mice,but it shown increase tendency in female EAE and there was no significant statistic difference between female EAE and female control.The counts of CD3+ T lymphocyte were significant increased in female EAE and male EAE heart by flow cytometry compared with female and male control,respectively.Moreover,the counts of CD3+ T lymphocyte was more increased in female EAE heart flow cytometry than male EAE mice.However,there was no significant statistic difference of CD3-CD19+ B lymphocyte in female and male EAE mice heart flow cytometry compared with female and male control,respectively.In addition,we studied the diversity of the intestinal microbiome in EAE mouse faeces.The OTU heatmap,Venn image,graphics of species relative abundance,alpha diversity,beta diversity(Unifrac distance matrix heatmap,PCA analysis,PCo A analysis and NMDS analysis)and the significance analysis of community structure difference between groups(Anosim,Metastats,LEf SE analysis)shown the similarity and difference degree of each group microbial community,and the important flora responsible for the difference.In conclusion,EAE induced severe cognitive function deficits and male EAE mice exhibited more severe cognitive function deficits than female EAE mice.Meanwhile EAE induced severe cardiac dysfunction and male EAE shown more severe cardiac dysfunction than female EAE mice.In addition,male EAE mice exhibited severe cardiac hypertrophy and cardiac fibrosis compared with male control.Moreover,male EAE induced the increase of inflammatory factor expression.Meanwhile the types of proliferating inflammatory cells were different between female and male EAE mice cardiac.