人脐带间充质干细胞移植对新生大鼠缺氧缺血性脑损伤的保护作用

Intracerebral transplantation of human umbilical cord-derived mesenchymal stem cells in neonatal rat model of hypoxic-ischemic brain damage: protective effect to injured brain

摘要:

目的 探讨人脐带间充质干细胞（hUC-MSCs）对新生大鼠缺氧缺血性脑损伤（HIBD）的保护作用及可能机制。方法 10 日龄 Sprague-Dawley 大鼠随机分为假手术组、HIBD 组和 MSCs 组，建立新生大鼠HIBD 模型，建模后 24 h MSCs 组侧脑室注入 hUC-MSCs。移植后 24、48 h 应用 TUNEL 及 Western blot 分别检测细胞凋亡及 Caspase-3 的表达；移植后 1、2、3 周应用 Longa 评分评价大鼠的神经行为，免疫荧光观察 hUC-MSCs 的存活、分化情况。结果 移植后 24、48 h，MSCs 组大鼠的细胞凋亡及 Caspase-3 的表达较 HIBD 组减少（P<0.05）；移植后 2、3 周，MSCs 组 Longa 评分低于 HIBD 组（P<0.05）；移植后脑组织中可见 BrdU 阳性细胞；MSCs组胶质纤维酸性蛋白（GFAP）及神经元特异烯醇化酶（NSE）阳性表达高于HIBD组及假手术组（P<0.05），随时间延长其表达逐渐增强（P<0.05）。结论 hUC-MSCs 移植治疗新生大鼠 HIBD 时，早期可抑制 Caspase-3的表达，减少细胞凋亡；后期存活的 hUC-MSCs 可分化为神经样细胞，并促进内源性神经样细胞的分化，发挥脑保护作用。

Abstract:

Objective To study the brain protection and the possible mechanism of human umbilical cord-derived mesenchymal stem cells（hUC-MSCs) in neonatal rat model of hypoxic-ischemic brain damage（HIBD). Methods Successfully establishing a neonatal rat model of HIBD, hUC-MSCs labeled with BrdU were transplanted into the lateral ventricle 24 hours after HIBD. The number of apoptotic cells and the expression of Caspase-3 were detected by TUNEL and Western blot respectively at 24 and 48 hours after transplantation. The neurological functions of HIBD rats were evaluated by Longa score, and the survival, differentiation and pro-differentiation effects of hUC-MSCs were identified by immunofluorescence at 1 to 3 weeks after transplantation. Results At 24 and 48 hours after transplantation, apoptotic cells and Caspase-3 expression in the MSCs group were less than in the HIBD group（P<0.05). At 2 and 3 weeks after transplantation, the Longa score in the MSCs group was lower than in the HIBD group（P<0.05). After transplantation, positive cells labeled with BrdU were seen in the brain tissue. The expression levels of glial fibrillary acidic protein（GFAP) and neuron specific esterase（NSE) in the MSCs group were higher than in the HIBD and sham-operated control groups（P<0.05), and increased gradually with the transplantation time（P<0.05). Conclusion hUC-MSCs transplantation in HIBD rats can inhibit Caspase-3 expression and reduce apoptotic cells in the early stage, and in the later period, the survival hUC-MSCs can differentiate into neural-like cells and promote the differentiation of endogenous neural-like cells, providing protective effects to brain.