新生大鼠缺氧缺血性脑损伤神经干细胞移植部位的探讨

The best site of transplantation of neural stem cells into brain in treatment of hypoxic-ishemic damage:experiment with newborn rats

目的探讨神经干细胞(NSC)移植治疗新生大鼠缺氧缺血性脑损伤(HIBD)的最佳部位。方法7d 龄新生大鼠制成 HIBD 模型后随机分为 HIBD 组(12只),皮质移植组(CT,12只),海马移植组(HT,12只)和侧脑室移植组(VT,12只)。移植4周后行放射形迷宫测试学习记忆和空间辨别能力,4项感觉运动功能测试测试感觉运动功能的恢复情况。计数皮质和海马 CA1区单位面积的正常神经元。结果在放射形迷宫测试中,成绩为 HT组>VT 组>CT 组>HIBD 组[觅水时间依次为(s):48±17、51±21、58±22、89±26],各组与 HIBD 组差异均有统计学意义(均 P<0.05)。感觉运动功能测试中的成绩为 CT 组>VT 组>HT 组>HIBD 组,其中 CT 组,VT 组和 HIBD 组的差异有统计学意义(均 P<0.05)。尼氏染色示皮质区正常神经元数:CT 组>VT 组>HT 组>HIBD 组,CA1区正常神经无数:HT 组>VT组>CT 组>HIBD组[依次为(细胞/mm^2):98±12、90±8、79±9、57±10,均 P<0.05]。结论 NSC 移植到侧脑室可有效改善新生大鼠 HIBD 的全脑损伤。

Objective To investigate the best site of transplantation of neural stem cells （NSCs） into the brain to treat hypoxic-ishemic damage （HIBD）. Methods Forty-eight 7-day-old Spraque-Dawley rats underwent ligation of the left common carotid artery and exposure to 8% oxygen at 37℃ for 2 hours to establish HIBD models and then were randomly divided into 4 equal groups 3 days later： HIBD control group, HIBD ＋ cortex transplantation group （CT group） undergoing NSC transplantation into the sensorimotor cortex, HIBD ＋ hippocampus transplantation group （ HT group） undergoing NSC transplantation into the hippocampus, and HIBD ＋ ventricle transplantation group （VT group ）, undergoing NSC transplantation into the lateral ventricle. Since the rats were 40-day-old, they underwent radial maze waterseeking test and 4 sensorimotor tests. Then the brains of the rats were taken out to undergo histological examination by Nissl staining and immunohistochemistry to observer the 5-bromodeoxyuridine （BrdU） expression. Results The times the rats took to find the water in all 3 arms of the maze were arranged form short to long in the order HT group 〈 VT group 〈 CT group 〈 HIBD group with significant differences between the HT, VT, and CT groups and HIBD group （All P 〈 0.05 ） and between the groups HT and VT and the group CT （ both P 〈 0.05 ）. The results of the 4 sensorimotor tests were arranged from the best to the worst in the order CT group 〉 VT group 〉 HT group 〉 HIBD group with significant differences between the groups CT and VT and the group HIBD （ both P 〈 0.05 ）. Nissl staining showed that the number of normal neurons in the cortex area from more to less were arranged in the order CT group 〉 VT group 〉 HT group 〉 HIBD group; and the number of normal neurons in the CAI area from more to less were arranged in the order HT group 〉 VT group 〉 CT group 〉 HIBD group. Conclusion Transplantation of NSC attenuates the brain damage and the cognitive and sensorimotor dysfunction after HIBD. Transplantation into the lateral ventricle is the most effective.