Therapeutic Benefit Of Intravenous Administration Of RMSCs And Bone Marrow Cells After Cerebral Ischemia In Adult Rats

Objective To test the hypothesis that mesenchymal stem cells and bonemarrow cells intravenously grafted migrate to infarct focus, survive there,differentiate into nerve cells, and promote restoration of injured brain and improveneurological function after cerebral ischemia in adult rats.Methods Bone marrow aspirates were taken from two months old rats. Ratmesenchymal stem cells (rMSCs) were cultured in vitro. To detect the surface markerantigens, the labeled cells of 4 passages were analyzed with FACScan flow cytometer.Adult male S-D rats were subjected to transient (2 hours) middle cerebral arteryocclusion (MCAO). rMSCs or bone marrow cells or phosphate buffered saline wereinfused into tail vein at 24 hours after MCAO respectively (n=16 in each group). Forcellular identification, rMSCs and bone marrow cells were pre-labeled with CTO.Functional outcome measurements using the modified Neurological Severity Scoreswere performed at 24 hours post-MCAO , 1 week and 2 weeks post-transplantationrespectively. Immunohistochemical staining and laser scanning microscopy were usedto identify rMSCs and cells derived from bone marrow in the brain sections.Results rMSCs could adhere to tissue culture plastic wall and werepolymorphic. After p5 culture, 1-2×10¹¹ cells were obtained. Following the time ofpassage increases, the positive rate of CD29 tends increase; CD90 tends decrease, thenegative rates of CD34 and CD45 tend increase. There was significant neurologicalfunction improvement in rats treated with rMSCs and bone marrow cells comparedwith that of control group, as evidenced by mNSS scores(p<0.001), there's notsignificant difference in mNSS scores between rMSCs and bone marrow cells treatedgroups. In the treated group the local lesions of brain were smaller than that of thecontrol group. After transplantation , rMSCs and cells derived from bone marrowsurvived and were localized to the ischemic core and its boundary zone, and a fewcells expressed NSE, nestin, NF-200 and GFAP. There were not significantdifferences in the differentiated rates between rMSCs and bone marrow cells treatedgroups. Conclusions rMSCs can expand rapidly in vitro and retain the capacity of stemcells. Both rMSCs and bone marrow cells can survive and localize to the ischemicarea of the brain, and express the phenotypic protein marker of neural cells.Intravenous administration of both rMSCs and bone marrow cells can promote theneurological functional improvement after stroke.