中文摘要：

目的：探讨脐血单个核细胞移植对缺氧缺血性脑损伤（HIBD）新生大鼠脑神经元凋亡及Bax、Bcl-2蛋白的影响。方法7日龄Sprague-Dawley新生大鼠制备缺氧缺血性脑损伤（HIBD）模型，随机分为正常对照（N）＋生理盐水（NS）、HIBD＋NS、N＋脐血单个核细胞（UCBMC）及HIBD＋UCBMC组。N＋UCBMC与HIBD＋UCBMC组侧脑室注入3×106个UCBMC，N＋NS与HIBD＋NS组注入等体积NS。移植后7d采用NeuN/活性Caspase-3免疫荧光双标染色法、TUNEL法观察大脑皮层神经元凋亡，Western blot观察脑组织Bax、Bcl-2蛋白表达。结果 HIBD＋NS组的NeuN＋活性Caspase-3＋DAPI＋细胞及TUNEL＋DAPI＋细胞均多于N＋NS和N＋UCBMC组（P〈0.01）；HIBD＋UCBMC组的NeuN＋活性Caspase-3＋DAPI＋细胞及TUNEL＋DAPI＋细胞均少于HIBD＋NS组（P〈0.01）。HIBD＋NS组的Bax蛋白表达高于N＋NS与N＋UCBMC组，Bcl-2蛋白低于N＋NS与N＋UCBMC组（P〈0.01）；而HIBD＋UCBMC组的Bax蛋白较HIBD＋NS组降低（P〈0.01），Bcl-2蛋白则高于HIBD＋NS组、N＋NS和N＋UCBMC组（P〈0.05）。结论 HIBD新生大鼠侧脑室移植UCBMC可以减轻神经元凋亡，其机制可能与Bcl-2蛋白表达上调，Bax蛋白表达下调有关。

英文摘要：

ObjectiveTo explore the effects of umbilical cord blood mononuclear cells （UCBMC） transplantation on the neuronal apoptosis and the expression of Bcl-2 and Bax proteins in neonatal rats with hypoxic-ischemic brain damage （HIBD）.MethodsSeven-day-old Sprague-Dawley neonatal rats were randomly divided into normal control （N）＋normal saline （NS）, HIBD ＋ NS, N＋UCBMC, and HIBD ＋ UCBMC groups. HIBD model was prepared using the classical Rice-Vannucci method. Twenty-four hours after HIBD, UCBMC were transplanted in the N＋UCBMC and HIBD＋UCBMC groups. Seven days after transplantation, NeuN/Cleaved-Caspase-3 double immunolfuorescence staining and TUNEL methods were used to observe neural apoptosis in the cortex. The expression levels of Bax and Bcl-2 proteins were examined by Western blot analysis.ResultsThere were more NeuN＋ cleaved Caspase-3＋DAPI＋ and TUNEL＋DAPI＋ cells in the HIBD＋NS group compared with the N＋NS and N＋UCBMC groups （P〈0.01）. There were less NeuN＋ cleaved Caspase-3＋DAPI＋and TUNEL＋DAPI＋ cells in the HIBD＋UCBMC group compared with the HIBD ＋NS group （P〈0.01）. The concentration of Bax protein was higher and that of Bcl-2 proteins was lower in the HIBD＋NS group compared with the N＋NS and N＋UCBMC groups （P〈0.01）. The concentration of Bax protein in HIBD＋UCBMC group was lower than that in the HIBD＋NS group （P〈0.01）. The concentration of Bcl-2 protein was higher compared with the HIBD＋NS, N＋NS and N＋UCBMC groups （P〈0.05）.ConclusionsUCBMC transplantation via lateral ventricle can upregulate the expression of Bcl-2 protein and down-regulate the expression of Bax protein, thus alleviating brain neural apoptosis in neonatal rats with HIBD.