Study on mesenchymal stem cells transplanting for the treatment of ischemic brain injury

Objective:To investigate the effect and mechanism of mesenchymal stem cells(MSCs)transplanted for treatment of ischemic brain injury in rats.Methods:The model of rats about cerebral ischemia-reperfusion injury was established with suture emboli method.40 adult male Sprague-Dawleye model rats were ramdomized into PBS control group and MSCs treated group.1 week later after 2 hours of middle cerebral artery occlusion,2×106 MSCs labeled with Bromodeoxyuridine(Brdu)and the same volume of PBS were transfered into MSCs treated group rats and PBS control group rats respectively through external carotid artery.The neurological deficits of rats were evaluated at every day after operation.Rats cerebral tissue was obtained at 1 w,2 w,3 w,4 w after cerebral ischemia-reperfusion injury,and area of infarct were investigated by HE dyeing.The SEPand histopathology was examined at different time points.Results:The neurological deficits of MSCs treated group rats(1W:9.77±2.54;2W:7.31±1.88;3W:6.97±2.46;4W:4.89±1.14)were much lower than PBS control group rats(1W:15.78±2.65;2W:14.42±3.23;3W:11.42±3.30;4W:9.82±2.19)(P0.05);Compared with PBS control group,histopathology of brain tissue presented that quantity of degenerative and necrotic neurocyte reduced,dropsy lessened obviously in MSCs treated group,Somatosensory evoked potentials of rats noticeable recovery in different time points(P0.05);Many Brdu positive cells existed in rat Infarct hemisphere of MSCs treated group at different time point,opposite side hemisphere had a little Brdu positive cells,they mainly existed in cerebral cortex,subcortex,hippocamp and so on.They were also some Brdu positive cells existed around vascular endothelial cell.The expression of BDNF in MSCs treated group was higher than the PBS control group at 2w,3w,4w.(P0.05).Conclusion:Through the external carotid artery,the transplanted MSCs could survive,migrate,excrete Brain-derived neurotrophic factors(BDNF)in rats brain,relieved cerebral ischemia-reperfusion injury,promoted neurofunctional recovery.The therapy of MSCs transplanted into rat brain after cerebral ischemia is effective.