重组人促红细胞生成素对新生大鼠缺氧缺血性脑损伤后神经细胞增殖与凋亡的影响

Effects of recombinant human erythropoietin on the proliferation and apoptosis of neural cells after hypoxic ischemic brain damage in newborn rats

目的研究重组人促红细胞生成素(rh Epo)对新生Sprague-Dawley (SD)大鼠缺氧缺血性脑损伤(hypoxic-ischemic brain damage,HIBD)后神经细胞增殖与凋亡的影响。方法随机将60只7日龄SD大鼠均匀分为对照组(假手术组)、HIBD组和rh Epo干预组。在HIBD组和rh Epo干预组中建立HIBD损伤模型,对照组仅做假手术处理。rh Epo干预组于建模前、缺血缺氧后0、24、48、72 h分别给予5000 U/kg rh Epo腹腔注射; HIBD组和对照组于相同时间点给予等量rh Epo空白对照品。末次给药后24 h,快速取脑,HE染色法检测大鼠海马区病理学改变,免疫组织化学法检测海马区齿状回5-溴脱氧尿嘧啶(Brd U)以及活性半胱氨酸天冬氨酸蛋白酶-3(Caspase-3)阳性细胞的表达。结果对照组大鼠海马齿状回部位脑组织神经细胞未见明显增生与凋亡变化,HIBD组则出现了明显的脑组织病理缺氧缺血侧神经元坏死,大量空泡样变性,核异常深染、固缩及脑组织萎缩,rh Epo干预组神经细胞病变较轻,双侧脑组织镜下结构改变不明显。三组间Brd U阳性细胞数以rh Epo干预组最多,HIBD组次之,对照组最少,组间差异有显著统计学意义(P<0.05);三组间Caspase-3阳性细胞数以HIBD组最多,rh Epo干预组较HIBD组显著降低,对照组则处于较低水平,组间差异有显著统计学意义(P<0.05)。结论外源性rh Epo可以刺激缺氧缺血性脑损伤后神经细胞增殖,抑制神经细胞凋亡,从而发挥神经保护作用。

Objective To study the effect of recombinant human erythropoietin(rh Epo)on the proliferation and apoptosis of neural cells of newborn rats suffered with hypoxic-ischemic brain damage(HIBD).Methods Sixty Sprague-Dawley(SD)rats(7 days old)were randomly divided into three groups:control group(sham surgery group,n=20),the HIBD group(n=20)and the rh Epo intervention group(n=20).HIBD model was established in the HIBD group and the rh Epo intervention group.Sham surgery was performed in the control group.Rats in the rh Epo intervention group were intraperitoneally injected with 5000 U/kg rh Epo before modeling and at 0,24 th,48 th,72 th h after ischemia and hypoxia.Rats in the HIBD group and the control group were given the same amount of rh Epo blank control.All rats were killed 24 hours after the last administration.Brain tissues were quickly collected.HE staining was performed to check the brain pathological changes of test rats.Immunohistochemistry staining was used to detect the number of 5-bromodeoxyuracil(Brd U)positive and caspase-3 positive neural cells in the hippocampal dentate gyrus.Results No obvious changes of proliferation and apoptosis were observed in the brain tissue of the control group.Obvious histopathological anoxia-ischemic neuronal necrosis,massive vacuolar degeneration,abnormal nuclear hyperchromatism,consolidation and brain tissue atrophy were noticed in the HIBD group.While,lighter neurocytopathic changes was presented in the rh Epo intervention group as compared with the HIBD group.Among the three groups,the number of Brd U positive neural cells was highest in the rh Epo intervention group,followed by the HIBD group and the control group.The difference among the three groups was statistically significant(P<0.01).The HIBD group has the highest number of caspase-3 positive neural cells,followed by the rh Epo intervention group and the control group.The difference among the three groups was statistically significant(P<0.01).Conclusions The neuroprotective effect of exogenous rh Epo in the situation of hypoxic ischemic brain injury was related to the stimulation of proliferation,as well as inhibition of apoptosis of neural cells.