骨髓基质细胞脑内移植对缺氧缺血性脑损伤新生大鼠脑白质的保护作用

Effect of intracerebral transplantation of rat bone marrow stromal cells on brain white matter of neonatal rats with hypoxic-ischemic brain damage

目的探讨骨髓基质细胞（BMSCs）脑内移植对缺氧缺血性脑损伤新生大鼠脑白质损伤的保护作用。方法34只7日龄新生SD大鼠，随机分为正常对照组（n=10）、HIBD组（n=12）和移植组（n=12），后两组大鼠结扎左颈总动脉后低氧暴露2h制作HIBD模型，移植组大鼠在HIBD后24h在大鼠脑立体定位仪下，将体外培养3～5代的SD大鼠BMSCs用Hochest33324标记24h后脑内移植于左侧海马。日龄45d时处死大鼠，用荧光显微镜观察BMSCs在脑内的存活及BMSCs的O4的阳性表达。行髓鞘碱性蛋白（MBP）检测左侧胼胝体和皮质下白质MBP表达，行O4免疫组织化学检测左侧侧脑室周围和皮质下白质O4的表达。结果BMSCs移植后37d，移植部位及左侧皮层区（损伤侧）均可见到胞核蓝色的BMSCs，移植细胞表达O4的阳性率为（3．70±1．09）％。HIBD组左侧（损伤侧）胼胝体和皮质下白质MBP染色变浅，有不同程度的髓鞘脱失改变，左侧侧脑室周围和皮质下白质04阳性细胞数较对照组明显减少，差异均有显著意义（P〈0．01）。移植组胼胝体和皮质下白质MBP染色较深，部分有髓鞘脱失改变，相同部位04阳性细胞数较对照组稍减少，比HIBD组明显增加，其差异有显著意义（P〈0．01）。结论BMSCs脑内移植对HIBD新生大鼠脑白质损伤具有保护作用。

Objective To study the effect of intracerebral transplantation of bone marrow stromal cells （BMSCs） on brain white matter of neonatal rats with hypoxic-ischemic brain damage （HIBD）. Methods Thirty-four 7-day-old neonatal rats were randomly assigned to three groups ： normal control （ n = 10）, HIBD （ n = 12） and HIBD ＋ BMSCs transplantation （ n = 12）. The HIBD and the HIBD ＋ BMSCs transplantation group rats were subjected to left carotid artery ligation, followed by hypoxia exposure for 2 hrs, in order to induce HIBD. The rats in the HIBD ＋ BMSCs transplantation group received transplantation of BMSCs labeled nucleus with Hochest 33324 into the left hippocampus 24 hrs after HIBD induction. Myelin basic protein （MBP） expression in the left corpus callosum and the subcortical white matter and the number of oligodendrocyte precursors positively stained 04 in the left periventricular area and the subcortical white matter were detected by immunohistechemistry at ages of 45 days. Results The labeled BMSCs survived and were found mainly in the left hemisphere 37 days after transplantation. The positive rate of 04 expressed by the transplanted BMSCs was 3.70 ＋ 1.09%. More hypomyelination in the left corpus callosum and the subcortical white matter, and less number of O4 positive oligodendrocytes in the left periventricular area and the subcortical white matter were found in the HIBD group compared with the normal control group （P 〈 0.01 ）. The HIBD rats receiving BMSCs transplantation had increased 04 positive oligodendrocytes in the left periventricular area and the subcortical white matter and improved MBP immunoreactivity in the left corpus callosum and the subcortical white matter compared with the HIBD group （ P 〈 0. 01 ）. Conclusions Intracerebral transplantation of BMSCs can improve brain white matter damage in neonatal rats with HIBD.