| Background and objectiveDue to the current progress and development of the society and the improvement of people’s living standards, the trend of the aging of the world makes the incidence rate of cerebrovascular diseases increase year by year. In modern life, high sugar, high fat, high salt diet and fast-paced lifestyle make the age of the patients with cerebrovascular disease progressively younger. In our country the cerebrovascular diseases is the first or the second cause of the death of the mid-aged and the aged,and its morbidity is high.Chronic ischemic is the common one of cerebrovascular disease, such as alzheimer’s disease (AD) and vascular dementia (VD) are included in nervous system degenerative disease,effect the quality of patients’life severity,and results in incubus of the patients、their families and the society.Chronic cerebral ischemia is a common pathological condition, refers to various causes of long-term insufficient of cerebral blood flow perfusion, can cause neurons apoptosis, glial cell proliferation, radical scavenging dysfunction, inflammation reaction and so on, could eventually lead cognitive and neural dysfunction. The main features of Hippocampus include learning and memory ability, which rich in glutamic acid can synaptic, due to the special structure of the delicate sex make it become the whole brain ischemia sensitive area. And cognitive function is closely related to the synaptic plasticity, the change of the synaptic transmission structure on neural cells can cause cognitive function change, dendritic spines constitute most excitability synaptic postsynaptic membrane, is the main information processing and storage place, the number of dendritic spines and length can reflect the pyramidal cells between the contact information and transfer degree. EphB2through regulating synaptic plasticity, and promote the maturity of dendritic spines, which affect learning and memory ability. Bone marrow mesenchymal stem cells transplantation can improve AD and diseases of the nervous system of cognitive dysfunction, can promote the damaged neurons synaptic regeneration and connecting, the transplantation improve chronic cerebral ischemic disease cognitive impairment research increase day by day, but the mechanism is not clear. In view of EphB2and dendritic spines and cognitive function relationships, whether BMSCs through EphB2improved cognitive, at present has not been reported. This study intends to use2VO model rats, tail vein injection BMSCs, application of water maze, immunohisto chemistry and Western-blot to observate the effect of bone marrow mesenchymal stem cells transplatation on cognitive impairment and the expression of EphB2in Hippocampus of the chronic cerebral ischemic rats.MethodsHealthy male SD rats72only,6months, weight450g or so, randomly divided into Sham operation group, model group and experimental group, choose8,10,12weeks three time points, each group of eight only. Healthy male SD rats,60-80g, used for bone marrow mesenchymal stem cells based on culture. The permanent bilateral common carotid artery ligation preparation chronic cerebral ischemia model. After the success of the model made1week, inject the fifth generation bone marrow mesenchymal stem cells2x106(blending in1ml PBS inside) through the rat tail vein, the rest of the group at the same time inject1ml PBS through the rat tail vein. Use water maze test to evaluate the learning and memory ability of rats in different time points. After the water maze test, put the rats to death, beheaded take brain, do immunohis to chemical, Western-blot to observate the EphB2expression in Hippocampal, use the SPSS17.0software statistics to process.Transfect the P5generation cells with the marked GFP virus, continue to cultivate2-3days,observate through the confocal fluorescence microscope. Take the cells2x106to inject the rats when made model1week from tail vein,1week after transplantation, put rats to death and fast take brain, frozen section and use the fluorescence microscope to observe whether the cells implanted into the brain.Results1. The result of BMSCs transplantation:Bone marrow mesenchymal stem cells can transplantate into2VO model rats through the rat tail vein;2. The result of Water maze test:Ischemia8,10,12weeks, and compared sham operation group, model group and experimental group were significantly prolong the escape latency (P<0.05). The same point in time, the escape latency period in experimental group is obviously reduced than model group (P<0.05).In the three time points, the escape latency period in sham operation group has no significant change (P>0.05).3.Immunohistochemical detection results:At the same time point, the expresstion of EphB2positive cells number in model group and experimental group is significantly reduced than sham operation group.(P<0.05), the experimental group is significantly increased than model group (P<0.05).4.Western-blot test results:In each group the hippocampus all have EphB2expression. At the same time, the expression of EphB2in model group and experimental group is significantly reduced than sham operation group(P<0.05), the EphB2expression in experimental group is significantly increased than model group (P<0.05).ConclusionsBone marrow mesenchymal stem cells can transplanted into the brian of the rats with chronic cerebral ischemia through tail vein injection and obviously improved the learning and memory ability of the rats,which may be by increasing the EphB2expression. |
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