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Objective:To observe the effects of exercise preconditioning on blood-brain barrier (BBB) permeability, and connexin 43 (Cx43) and pannexin 1 (Panx1) protein after cerebral ischemia-reperfusion injury in rats. Methods:Fifty-four male Sprague-Dawley rats were randomly divided into sham group (n = 18), model group (n = 18) and exercise preconditioning group (n = 18). The exercise preconditioning group was trained with treadmill for three weeks before modeling. The middle cerebral arteries were occluded in the model group and the exercise preconditioning group using the modified Koizumi suture. After reperfusion of 24 hours, the rats were assessed with modified Neurological Severity Score (mNSS). The permeability of BBB was observed with Evans blue (EB). The expression of Cx43 and Panx1 was detected with Western blotting and immunohistochemistry in the ischemic tissues. Results:Compared with the model group, the mNSS score decreased in the exercise preconditioning group (P < 0.05), while the Evans blue content and the expression of Cx43 and Panx1 decreased (P < 0.05), as well as the the positive areas of Cx43 and Panx1 (P < 0.05). Conclusion:Exercise preconditioning can improve the permeability of BBB in cerebral ischemia-reperfusion rats, which may associate with down-regulation of Cx43 and Panx1, to protect brain from injury.
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Objective:To investigate the effects of enriched environment on hippocampal neuronal apoptosis and brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) signaling pathway in neonatal rats with hypoxic-ischemic brain damage. Methods:Forty-eight newborn Wistar rats aged seven days were randomly divided into sham operation group, model group and enriched environment group, each group was divided in to 14 days group and 28 days group, with eight in each subgroup. The model was established with the Rice method. The sham operation group and the model group did not receive any intervention, and the enriched environment group received enriched environment stimulation 24 hours after modeling. Fourteen days and 28 days after modeling, the levels of neuronal apoptosis in hippocampus were detected by TUNEL and double immunofluorescence staining; BDNF and TrkB proteins in hippocampus were detected by immunohistochemical staining. Results:Fourteen days and 28 days after modeling, the numbers of TUNEL positive cells, double immunofluorescence positive cells, BDNF and TrkB positive cells were significantly more in the model group than in the sham operation group (t > 27.214, P < 0.001), while the numbers of TUNEL positive cells, double immunofluorescence positive cells were significantly less in the enriched environment group than in the model group (t > 12.687, P < 0.001); and the number of BDNF and TrkB positive cells were significantly more in the enriched environment group than in the model group 28 days after modeling (t > 137.998, P < 0.001). Conclusion:Enriched environmental stimulation could reduce the apoptosis of hippocampal neurons, and up-regulate the expression of BDNF and TrkB proteins in the neonatal rats with hypoxic-ischemic brain damage.
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The concept of neurovascular units studies the interaction between neural cells and blood vessels, regards the blood-brain barrier as the core,and relates with the neurodegenerative diseases.This paper reviewed the relationship be-tween neurovascular units and neurodegenerative diseases, such as Alzheimer's disease, amyotrophic lateral sclerosis, Huntington's disease,multiple sclerosis,etc.
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Exosome is a hot topic in the field of medical research in recent years, which can serve as new carriers for cell-to-cell communication, and show great potential in the diagnosis and treatment of ischemic stroke. microRNA containing in exosomes plays an important role in it. This article reviewed the research progress of exosomes in ischemic stroke on biomarkers, drug carriers, neurovascular remodeling, and treatment.