脐血单个核细胞移植对缺氧缺血性脑损伤新生大鼠促红细胞生成素蛋白及少突胶质祖细胞的影响

Effects of umbilical cord blood monocytes transplantation on EPO protein and oligodendrocyte progenitors in neonatal rats with hypoxic-ischemic brain damage

摘要:

目的 探讨脐血单个核细胞(UCBMC)移植对缺氧缺血性脑损伤(HIBD)新生大鼠脑促红细胞生成素(EPO)蛋白及少突胶质祖细胞的影响。方法 7 日龄健康 Sprague-Dawley 新生大鼠40只随机分为正常对照组、HI组、UCBMC对照组和HI+UCBMC组,每组10只。采用经典Rice法制成HIBD模型,造模24 h后,正常对照组和HI组经侧脑室注入2 μL PBS,UCBMC对照组和HI+UCBMC组经侧脑室注入3×10⁶ UCBMC。移植后7 d,采用EPO/DAPI与NG2/DAPI免疫荧光双标法观察损伤侧室管膜下区(SVZ)EPO蛋白及少突胶质祖细胞的变化,并进行相关性分析。结果 移植后7 d,HI+UCBMC组NG2⁺DAPI⁺及EPO⁺DAPI⁺细胞数均显著高于UCBMC对照组(均P<0.05)、HI组及正常对照组(均P<0.01),UCBMC对照组NG2⁺DAPI⁺及EPO⁺DAPI⁺细胞数均显著高于正常对照组和HI组(均P<0.01),正常对照组NG2⁺DAPI⁺细胞数显著高于HI组(P<0.01)。HI+UCBMC组NG2⁺DAPI⁺细胞数与EPO⁺DAPI⁺细胞数呈正相关(r=0.898)及直线回归(β=1.4604,P<0.01)。结论 UCBMC可促进HIBD新生大鼠少突胶质祖细胞的表达,其机制与EPO蛋白的表达增加相关,从而修复脑白质损伤。

Abstract:

Objective To study the effects of umbilical cord blood monocytes (UCBMC) transplantation on erythropoietin (EPO) protein and oligodendrocyte progenitor cells in hypoxia-ischemia (HI) neonatal rats. Methods Forty seven-day-old Sprague-Dawley rats were randomly divided into normal control (N), HI, UCBMC and HI+UCBMC groups (n=10 each). Hypoxic-ischemic brain damage (HIBD) model was prepared according to the Rice method. Twenty-four hours after hypoxia, the N and HI groups were injected with 2 μL phosphate buffered saline (PBS), and the UCBMC and HI+UCBMC groups were injected with 3×10⁶ UCBMC via the lateral ventricle. EPO protein and oligodendrocyte progenitor cells in the subventricular zone of the injured brain were observed by EPO/DAPI and NG2/DAPI immunofluorescence double staining, and their correlation was analyzed. Results Seven days after transplantation, there were more NG2⁺DAPI⁺ and EPO⁺DAPI⁺ cells in the HI+UCBMC group than in the UCBMC (P<0.05), N and HI groups (P<0.01). More NG2⁺DAPI⁺ and EPO⁺DAPI⁺ cells were observed in the UCBMC group compared with the N and HI groups (P<0.01). There were more NG2⁺DAPI⁺ cells in the N group than in the HI group (P<0.01). The number of NG2⁺DAPI⁺ cells was correlated with the number of EPO⁺DAPI⁺ cells in the HI+UCBMC group (r=0.898, β=1.4604, P<0.01). Conclusions UCBMC can promote expression of oligodendrocyte progenitor cells, which is correlated with an increase in EPO protein and thus repairs brain white matter damage in neonatal rats with HIBD.