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Objective To investigate the mechanism of action of Huzhang Qingmai decoction (HZQMY) on the improvement of cognitive function in mice with chronic cerebral ischemia from the perspective of intestinal flora. Methods A mouse model of chronic cerebral ischemia was established by placing microcoils around the bilateral common carotid arteries to induce bilateral carotid artery stenosis (BCAS). After 12 weeks of intragastric administration, the cognitive function of the mice was measured by the Morris water maze; the myelin damage was analyzed by LFB staining; The contents of the cecum of the mice in each group were extracted and analyzed by 16S rRNA sequencing. Results The results of the water maze experiment showed that the mice in the HZQMY group had a significantly shorter escape latency, increased the number of crossings platform and the percentage of target quadrants. LFB staining showed that the white matter damage in the model group was severe; the white matter damage in the HZQMY group was milder. The results of 16S rRNA sequencing showed that compared with the model group, the abundance of Verrucomicrobiota, Akkermansia, and ErysiPelatoclostridium capsulatum in the intestinal flora in HZQMY group was significantly reduced (P<0.05), while the abundances of Eubacterium_xylanoPhilum and Allobaculum were significantly increased (P<0.05). Conclusion The protective effect of HZQMY, which has the effect of improving cognitive function in mice with chronic cerebral ischemia, may be related to the regulation of intestinal flora in mice with chronic cerebral ischemia.
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AIM:To investigate the regulatory effects and underlying molecule-mechanism of clonidine on learning and memory in rats with chronic cerebral ischemia.METHODS: Sprague-Dawley rats(n=45)were randomly divided into sham-operation group,cerebral ischemia model group and clonidine group,15 rats in each group.The chronic cerebral ischemia rat model was established by right middle cerebral artery occlusion for 2 h and reperfusion for 30 d. Clonidine was administrated by i.g.for 7 days in clonidine group.The ability of spatial reference memory of the rats with cerebral ischemia was tested by Morris water maze.The protein levels of extracellular signal-regulated kinase 1/2(ERK1/2),phosphorylated ERK1/2(p-ERK1/2), cAMP-response element binding protein(CREB)and phosphorylated CREB (p-CREB)were determined by immunohistochemistry and Western blot.RESULTS:The results of Morris water maze test showed that compared with the sham-operation group,the ability of spatial reference memory was obviously impaired in the cerebral ischemia model group.Compared with the cerebral ischemia model group,the ability of spatial reference memory in the clonidine group were improved.Compared with the sham-operation group, the protein levels of p-ERK1/2 and p-CREB in hippocampus were increased in model group(P<0.01).Compared with the cerebral ischemia model group,the protein levels of p-ERK1/2 and p-CREB in hippocampus were decreased in the clonidine group(P<0.01).CONCLU-SION:Clonidine improves the learning and memory abilities of the rats with cerebral ischemia, and ERK1/2 and CREB are involved in this process.
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OBJECTIVE Vascular dementia (VD) refers to a progressive decline in memory and cognitive function caused by chronic cerebral ischemia. 2-Vessels occlusion (2-VO) has been widely used as a model of VD. Xiao-Xu-Ming decoction, a well-known traditional Chinese medicine prescrip-tion,has been widely used to treat stroke and sequelae of stroke.The present study was to investigate the mechanism of Xiao-Xu-Ming decoction(XXM) against chronic cerebral ischemia injury in rats. METHODS After XXM treatment, rats were performed a memory testing with Morris water maze and motor ability testing using prehensile test and inclined screen test.Neuronal plasticity was observed by immunofluorescent staining with MAP2 antibody. Differentially expressed proteins of rat hippocampus were analyzed by Label-free quantitative proteomics. RESULTS XXM significantly alleviated 2-VO-induced learning and memory deficits, motor ability dysfunction, and neuronal plasticity injury in rats. The mechanism might be involved in up-regulation of 39 proteins and down-regulation of 13 proteins in the hippocampus of rats after XXM treatment vs 2-VO group rats.Gene ontology and pathway analysis showed that the regulated proteins are mainly involved in oxidation reduction process, intracellular signaling cascade process, and protein catabolic process, etc. The signal pathways are mainly involved in ubiquitin mediated proteolysis and phosphatidylinositol signaling system. CONCLUSION Current findings provide new insights into the molecular mechanisms of XXM on chronic cerebral ischemia.
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Objective To measure middle cerebral artery (MCA) hemodynamic parameters of chronic cerebral ischemia in middle aged and elderly people with phase contrast magnetic resonance imaging (PCMRI),and to explore cerebral blood flow dynamic pattern in different degrees of chronic cerebral ischemia patients.Methods Middle aged and elderly people underwent conventional MRI scan,and were divided into 12 cases of the normal group,16 cases of mild cerebral ischemia group and 13 cases of obvious cerebral ischemia group.All groups underwent bilateral MCA PCMRI.Bilateral MCA hemodynamic parameters and phase-velocity curve in a heartbeat cycle were obtained by QFLOW analysis software on the workstation for post-processing.Bilateral MCA vascular area,peak velocity (PV),mean velocity (MV) and mean flow (MF) were recorded.The differences of bilateral MCA hemodynamic parameters among the three groups were compared by SPSS17.0 software.Results Bilateral MCA vascular area,MV,MF and right MCA PV among three groups were statistically significant by one-Way ANOVA (P＜0.05).Compared with normal group,systolic peak of bilateral MCA phase-velocity curve was low,dull,widen,and the connection between the diastolic peak and systolic peak became flattened in chronic cerebral ischemia patients.Conclusion PCMRI can reflect the differences of the cerebral blood flow dynamic change pattern between different degrees of chronic cerebral ischemia.
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Aim To investigate the effects and possible mechanisms of kaemperol in the rats with chronic cere-bral ischemia.Methods Chronic cerebral hypoperfu-sion model was produced by permanent occlusion of bi-lateral common carotid arteries (2VO)in rats.After KAE treatment,the rats underwent Morris water maze and prehensile traction test.Neuronal morphology was observed using Nissl and HE staining.The activity of SOD and the content of MDA in brain tissue were de-termined.The DJ-1 protein expression was assayed by Western blot.Results Compared with 2VO model group,KAE significantly improved learning and memo-ry and the grasping ability.In addition,KAE signifi-cantly reduced brain tissue pathological injury induced by 2VO. Furthermore, KAE significantly increased SOD activity and enhanced antioxidant protein DJ-1 ex-pression in brain tissue.Conclusions KAE could sig-nificantly attenuate the cognitive impairment,limb bal-ance dysfunction and pathological injury in rats with chronic cerebral ischemia.The mechanism may be re-lated to improving the antioxidant system in vivo.
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Objective To investigate the therapeutic effect and mechanism of total flavone of haw-thorn leaf ( TFHL) on p38MAPK signaling pathway and inflammation factors in rats brain with chronic cere-bral ischemia.Methods SPF class healthy male SD rats were randomly divided into sham group, model group,TFHL group and Ginkgo leaf group( 12 rats in each group) .Permanent bilateral carotid artery ligation was used to prepare chronic cerebral ischemia model.Morris water maze method was used to evaluate learn-ing and memory abilities of rats.Immunohistochemistry and Western blot methods were used to measure the expression of caspase-3 and p38MAPK proteins.ELISA method was used to measure the amounts of TNF-αand IL-1βin hippocampal tissue.Results Compared with the model group,TFHL treatment (36 d) can im-prove learning and memory capabilities of vascular dementia rats,shorten the escape latency ( TFHL group(10.01±2.85) s vs Model group (19.54±6.12) s, P<0.05) and the course of searching platform(TFHL group(2.6044±0.3219)m vs model group(3.3502±0.6231)m, P<0.05),increase the numbers of crossing the platform (TFHL group(5.17±2.12) times vs Model group (3.96±1.34) time,s P<0.05) and the platform quadrant swimming distance percentage (TFHL group(48.22±7.39)%vs model group (33.42±5.32) %, P<0.01).The number of caspase-3 positive cells in the hippocampus significantly reduced (TFHL group(1.677 ±0.164) vs Model group (2.387±0.171), P<0.05),the expression level of P38MAPK protein (TFHL group (0.0161±0.0003) vs Model group (0.0254±0.0018), P<0.05),TNF-α(TFHL group(19.61±3.61) ng/10 mg vs Model group (27.82±6.57) ng/10 mg, P<0.01)and IL-1β(TFHL group(24.41±2.56) ng/10 mg vs Model group (29.43±5.26) ng/10 mg, P<0.05) were significantly decreased.Conclusion TFHL plays a protective role in nerve function of the chronic cerebral ischemia rats.The mechanism of its antia-poptosis might be associated with the activation of P 38MAPK signaling pathway,inflammation and the apoptosis of neurons in the brain.
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Objective To explore the roles of glycogen synthase kinase-3β (GSK-3β) in cognitive dysfunction and emotional alterations after rat's chronic cerebral ischemia.Methods 51 SD rats were randomly divided into sham group (sham group,n=17),chronic cerebral ischemia group (2VO group,n=17),chronic cerebral ischemia group + LiCl group (2VO + LiCl group,n=17),according to the table of random number.All groups were intraperitoneally injected with LiCl or saline on 3rd,7th,14th,21 st and 28th day,and then produced the chronic cerebral ischemia models.On the 28th day after model,the spatial learning and memory,fear memory,and anxiety emotion were detected.Results The Morris water maze test showed that 2VO group spent longer latent time searching and finding the platform than sham group (4th day P＜0.01,3rd,5th,6th,7th day P＜0.05).2VO+LiCl group spent shorter latent time than 2VO group (4th day P＜0.01,5th,6th,7th day P＜0.05).After removing the platform,2VO group spent longer time arriving the former location than sham group (P＜0.05).And 2VO+LiCl group spent dramatically different time compared to 2VO group (P＜0.01).Step-down test showed 2VO group spent shorter latent time than sham group (2VO group:(41.00±1.87)s,sham group:(44.55±2.77)s) (P＜0.05).2VO+ LiCl group spent dramatically longer latent time compared to 2VO group (2VO +LiCl group:(43.40± 1.35)s) (P＜ 0.05).2VO group made much more mistakes times than sham group (P＜0.05).2VO+LiCl group made dramatically less mistakes times compared to 2VO group (P＜0.05).The elevated plus maze test showed 2VO group had much less ratio of retention time in open arms (among total arms retention time) than sham group (2VO group:(0.23± 0.01),sham group:(0.25± 0.01)) (P＜ 0.01).2VO + LiCl group had much larger ratio than 2VO group (2VO + LiCl group:(0.24±0.01),P＜0.05).2VO group had much less ratio of entry times in open arms (among total arms entry times) than sham group (P＜0.01).2VO+LiC1 group had much larger ratio than 2VO group(P＜0.05).Conclusion Chronic cerebral ischemia can lead to deterioration of learning and memory,and anxiety emotion for rats.However,inhibition of GSK-3β can ameliorate these alterations.
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Objective To explore the roles and related mechanisms of Protein Phosphatase 2A(PP2A) in cognitive dysfunction after the chronic cerebral ischemia.Methods 70 male Sprague Dawley rats in clean degree were divided into sham group,chronic cerebral ischemia group (Bilateral carotid arteries occlusion,2VO),and chronic cerebral ischemia group with PP2A activation group(2VO+aPP2A).The rats were injected intraperitoneally with 1.88 μmol/ml sodium selenate(15 μmol · kg-1 · d-1) or equal volume of saline for 4 weeks.After one month,the chronic cerebral ischemia models were reproduced by the occlusion of bilateral common caroid artery.Then the abilities of learning and memory were tested by Morris water maze,electrophysiological indices were recorded to analyze the LTP changes,and destribution of synaptic vesicles was observed by electron microscope.Results Morris water maze test showed that the 2VO group had significantly longer latent time than sham group in searching platform(P＜0.05),and the 2VO+aPP2A group had dramatically shorter latent time (P＜0.01) than that of 2VO group.Then removing platform to test the rats memory,the data showed that 2VO group spent markedly longer time than sham group to reach the location of the former platform (sham group:(14.50±1.98)s ; 2VO group:(17.30±2.11) s) (P＜0.01),and the 2VO+aPP2A group((15.09± 1.45) s) spent dramatically shorter latent time(P＜0.05) than that of 2VO group.The electrophysiological data showed that 2VO group had the noticeably smaller field excitable postsynaptic potential slope (fEPSP) slope ratio between pre and post of the high frequency stimulations (Long-term potential,LTP) than sham group(sham group:1.69±0.27; 2VO group:2.02±0.137) (P＜0.01),and the 2VO+aPP2A group(1.86±0.19) had strikingly higher ratio than that of 2VO group(P＜0.01).The electromicroscope observation showed that presynaptic vesicles density of 2VO was remarkably lower than that of sham group (sham group:(4.51±0.29) /μm2 ; 2VO group:(2.02±0.14) /μm2) (P＜0.01),and presynaptic vesicles density of 2VO+aPP2A group((3.58±0.50) /μm2) was noticeably higher than that of 2VO group(P＜0.01).Conclusion Activating PP2A can prevent the cognitive dysfunction after chronic cerebral ischemia through regulating LTP and synaptic vesicle density.And PP2A is probably a potential target for preventing and treating the cognitive dysfunction after chronic cerebral ischemia.
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Objective To investigate the damage of hippocampal neurons induced by chronic cerebral ischemia in the rats,and to clarify its mechanism.Methods 90 healthy adult male SD rats were randomly divided into sham operation group (n=30 ) and experimental group (n=60 ). The chronic cerebral ischemia rat models were established by permanently ligating the common carotid arteries on both sides of the rats in experimental group.The rats in sham operation group were established by incising the cervical median,only the common carotid arteries on both sides were separated without ligating. The rats in sham operation group and experimental group were respectively sacrificed at the 7th,14th and 21st day after operation.At each time point 10 rats in sham operation group and 20 rats in experimental group were selected and sacrificed.Immunohistochemistry staining was used to observe the dynamic changes of the expression levels of choline acetyltransferase(ChAT)in hippocampus neurons, and TA-FE method was used to observe the dynamic changes of hippocampal microvascualr architecture. MiVnt image analytical system was used to quantitatively analyze the immunohistochemistry result,the microvessel density (MVD)and micorvessel area density (MVA)of horizontal part of hippocampus in the rats. Results Compared with sham operation group,the ChAT expression levels in hippocampus neurons of the rats in experimental group at different time points were significantly decreased(P<0.05);and with the prolongation of time,the ChAT expression levels were gradually decreased;the ChAT expression level in 14-day experimental group was significantly lower than that in 7-day experimental group (P<0.05 );the ChAT expression level in 21-day experimental group was significantly lower than those in 7-day and 14-day experimental groups(P<0.05).The MVD and MVA of hippocampus of the rats in experimental group at different time points were obviously decreased compared with sham operation group(P<0.05);the MVA was gradually decreased with the prolongation of time, and the MVA of hippocampus of the rats in 21-day and 14-day experimental groups were obviously decreased compared with 7-day experimental group(P<0.05);the MVD was gradually decreased with the prolongation of time,the MVD of hippocampus of the rats in 21-day and 14-day experimental groups was obviously decreased compared with 7-day experimental group(P<0.05);the MVD of hippocampus of the rats in 21-day experimental group was obviously decreased compared with 14-day experimental group(P<0.05).Conclusion Chronic cerebral ischemia can lead to the progressive decrease of the ChAT expression level,MVD and MVA of hippocampus of the rats to aggravate gradually the learning and memory dysfunction, which may be one of the reasons of vascular dementia.
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Objective To investigate the effects of escitalopram (ESC)on the cognitive function,the expression of brain-derived neurotrophic factor (BDNF)in the hippocampus,the dendritic length and arborization and dendritic spines density of chronic cerebral ischemic rats.Methods Rats were randomly divided into sham-operation group,model group (permanent occlusion of bilateral common carotid arteries,2VO)and experimental group (treated with escitalopram at the dosage of 30 mg/kg·d).Rats were selected as study objects at week 1,2,4 and 8 after administration in each group.Their cognitive function was evaluated by the Morris water maze,the expression of BDNF protein was measured by Western blot,and dendritic morphology was studied by Golgi staining. Results In the Morris water maze test,the escape latency obviously extended in model group and experimental group compared with that in sham-operation group (P<0 .0 5 ),while the escape latency was shorter in experimental group than in model group (P<0.05).Compared with those in sham-operation group,the dendritic length and arborization and the density of dendritic spines in hippocampal CA1 significantly decreased in model group and experimental group (P<0 .0 5 ),while they increased significantly in experimental group compared with model group (P<0.05)by Golgi staining.Compared with sham-operation group,the expression of BDNF in the hippocampus of experimental group and model group significantly decreased (P<0 .0 5 ),but it increased significantly in experiment group compared with model group (P<0.05)by Western blot.Conclusion Escitalopram could significantly delay the progression of cognitive impairment induced by chronic cerebral ischemia in rats.The improvement of learning and memory may be related to the increased expression of BDNF.
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OBJECTIVE: In Moyamoya disease, the primary goal of treatment is to improve collateral circulation through angiogenesis. In the present study, we obtained and sub-cultured bone marrow stromal cells (BMSCs) from rats without a cell-mediated immune response. Then, we injected the labeled BMSCs directly into adjacent temporal muscle during encephalomyosynangiosis (EMS). Three weeks after BMSC transplantation, we examined the survival of the cells and the extent of neovascularization. METHODS: We divided 20 rats into a BMSC transplantation group (n=12) and a control group (n=8). Seven days after the induction of chronic cerebral ischemia, an EMS operation was performed, and labeled BMSCs (1x106(6)/100 microliter) were injected in the temporal muscle for the transplantation group, while an equivalent amount of culture solution was injected for the control group. Three weeks after the transplantation, temporal muscle and brain tissue were collected for histological examination and western blot analysis. RESULTS: The capillary/muscle ratio in the temporal muscle was increased in the BMSC transplantation group compared to the control group, showing a greater increase of angiogenesis (p<0.05). In the brain tissue, angiogenesis was not significantly different between the two groups. The injected BMSCs in the temporal muscle were vascular endothelial growth factor (VEGF)-positive by immunofluorescence staining. In both temporal muscle and brain tissue, the expression of VEGF by western blot analysis was not much different between the two groups. CONCLUSION: During EMS in a chronic cerebral ischemia rat model, the injection of BMSCs resulted in accelerated angiogenesis in the temporal muscle compared to the control group.
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Animals , Rats , Blotting, Western , Bone Marrow , Brain , Brain Ischemia , Collateral Circulation , Fluorescent Antibody Technique , Mesenchymal Stem Cells , Moyamoya Disease , Temporal Muscle , Transplants , Vascular Endothelial Growth Factor AABSTRACT
Objective To investigate the brain protection effect of cinnamon water extract on chronic cerebral ischemia rats. Methods We selected male Wistar rats to make chronic cerebral ischemia model by bilateral carotid artery ligation permanently,and the models were randomized into a model group,cinnamon high or low dose group,with 20 in each group. A control group with 20 rats was treated with sham operation. The cinnamon high and low dose groups were given cinnamon water extract 4.2g/kg and 2.1g/kg respectively by gavage in succession for 4 weeks. Y-maze test was used to test the cognitive ability of the rats. The superoxide dismutase (SOD) activity,malondialdehyde (MDA) content,and the expressions of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) were determined. Results Compared with the sham-operated group,the cognitive ability of the model group declined,the SOD activity of brain tissues decreased,and the MDA content increased. Cinnamon improved the SOD activity,reduced the MDA content,increased the NGF and BDNF expressions,and the effect of high-dose group was better than that of the low-dose group. Conclusion Cinnamon plays its role in cerebral protection through increasing the SOD activity and expression of NGF and BDNF and reducing content of MDA.