Distribution And Transformation Of Intravenous Administration Of Mesenchymal Stem Cells After Cerebral Ischemia In Rats

PrefaceMesenchymal stem cells ( MSCs) have capacity for multipotential differentiation. MSCs have been more and more proved to differentiate into neural cells by lots of reseachs. MSCs express neural phenotype and migrate when placed in adult rat damaged brain and spinal cord. Systemic infusion of male BM cells into irradiated female mice results in an influx of Y chromosome cells into the brain. Intravenous infusion of bone marrow derived marrow stromal cells could enter the brain and reduce neurological functional deficits after stroke in rats. We search the distribution and differentiation of intravenous administration of MSCs after cerebral ischemia in rats, discover its possible mechanism.Materials and Methods1. Materials1.1 Study objective: Adult male Wistar rats (n = 30) weighing 270 to 300 g;Two weeks old Wistar rats.1.2 Instrument: Light and fluorescent microscopy (Olympus, BH - 2) , CO2 -incubator, et al.1.3 Reagents:Fetal buffer serum, Bromodeoxyuridine, Mouse anti -BrdU monoclone antibody, anti - NSE antibody, anti - GFAP antibody, SABC - per-oxydase kit, SABC -FITC kit, et al.2. MethodsMSCs were abstracted and cultured. Rats were subjected to 2 hours of middle cerebral artery occlusion. For cellular identification, MSGs were prelabled with bromodeoxyuridine and intravenously infused at 24 hours after middle cerebral artery occlusion. Immunohistochemistry was used to identify the mesenchymal stem cells in brain.ResultIntravenous administrated MSCs migrate into brain. Cells derived from MSCs were characterized by round - to - oval dark brown nuclei with irregularly shaped and thin cytoplasm by BrdU staining. Only cells with this morphology and with BrdU localized solely to nucleus were counted as MSCs. Most of them survive and are localized to the ipsilateral ischemia hemisphere, cell population (15002.75 ±4972.64). Some on the isoloci zone of contralateral nonischemic hemisphere, cell population (999.58 ±655.41). The location of MSCs in some brains seems to be symmetry distribution. Lots of MSCs encircled vessels of cortex. There is not BrdU - positive cell in the brains of sham operated rats.A few cells express protein marker phenotypic neural cells in ischemia hemisphere. The percentage of BrdU that labeled expressed NSE and GFAP proteins was 4.46% ±1.91% and 3.89% ±0.84% respectively.DiscussionMore MSCs were found in the lesioned hemisphere than in the intact hemisphere. These data are consistent with reports that maleBM cells systemically infused into female ischemic rats migrate preferentially to ischemic cortex. The mechanisms responsible for intravenously infused BM migration into ischemic zone and its contralateral nonischemic zone are not clear. Disruption of the blood - brain barriermay facilitate selective entry of MSCs into ischemic brain. However it isnt prerequisite. This movement is genetically controlled in part through changes in expression of cell surface adhesion molecules, such as intercellular...