Protective effect of intracerebral transplantation of human mesenchymal stem cells on hypoxic-ischemic brain damage in rats / 第二军医大学学报

ABSTRACT

Objective: To explore the migration,differentiation and the therapeutic effect of intracerebral transplantation of human mesenchymal stem cells (hMSCs) after hypoxic-ischemic brain damage in rats, and to test whether three anti-hMSCs monoclonal antibodies prepared by our group can detect hMSCs in rat brains. Methods: hMSCs were isolated and purified by density gradient centrifugation and adherence to culture flask. Cells of passage 3-5 were prelabeled with bromodeoxyuridine (BrdU) for 72 h before transplantation. Animal models of hypoxic-ischemic brain damage (HIBD) were built with 1 month old Wistar rats. Three days after hypoxia-ischemia, HIBD rats in hMSCs-treated group (n=18) received intracerebral transplantation of 5×105 hMSCs. In control group (n=18) HIBD rats received phosphate buffered saline of the same volume. In sham-operated group (n=6) and HIBD group (n=6), rats did not receive any transplantation. Rats in hMSCs-treated group and control group were allowed to survive for 0 day,3 days, 1 weeks,2 weeks (all n=3) and 4 weeks (n=6, after transplantation). Rats in sham-operated group and HIBD group were allowed to survive for 31 days (4 weeks after transplantation). Rats of all the 4 groups received behavior test (alternative electro-stimulus Y-maze) 4 weeks after transplantation before sacrificed; their brains were sectioned for H-E staining. The brains from all rats were also prepared for immunohistochemistry analysis to detect the distribution of hMSCs. Results: Immunohistochemistry results showed that hMSCs migrated mainly along the ventricular system 1 week later,and a few hMSCs migrated along the corpus callosum to the opposite side. Four weeks after transplantaion, hMSCs migrated to the parenchyma and distributed throughout the cerebra. Behavior test showed that the total errors (TE) in hMSCs-treated group (TE= 5.00±2.82) were significantly less than those in the control group (TE = 12.67±3.72, P < 0.05). H-E staining showed that the brain damage in the hMSCs-treated group was slighter than that of the control group and HIBD group. Conclusion: After transplanted in the brain of rats,hMSCs can survive and migrate in the central nervous system (CNS). hMSCs can promote tissue repair and functional recovery of rat brain, suggesting that hMSCs might be a possible treatment for hypoxic-ischemic brain damage.