人重组促红细胞生成素对大鼠创伤性颅脑损伤后神经细胞凋亡的影响及机制研究

The effect and mechanism of Rh-EPO on neuronal apoptosis after traumatic brain injury in rats

目的研究人重组促红细胞生成素(Rh-EPO)对大鼠创伤性颅脑损伤(TBI)后神经细胞凋亡影响,探讨其神经保护作用及作用的可能机制。方法选择55只健康雄性成年Wistar大鼠,鼠龄21周,体质量(220±20)g。随机数字表法分成假手术组(5只)、TBI组(25只)及Rh-EPO组(25只),TBI组和RhEPO组分别按2、6、24、72、168h时间点分为5个亚组,各5只。各组麻醉后,假手术组仅切开头皮,咬除颅骨,形成骨窗。TBI组和Rh-EPO组用Myneurolab脑立体定向仪及Beckman撞击器制造大鼠重型TBI模型,Rh-EPO组予以Rh-EPO 5000IU/kg腹腔注射。采用免疫组织化学SP法检测Bcl-2表达脑组织,并应用流式细胞仪检测脑组织神经元细胞凋亡率。结果与假手术组相比,TBI组脑组织神经元细胞凋亡率及Bcl-2的表达水平显著升高(P<0.01);与TBI组相比,Rh-EPO组Bcl-2表达升高,神经细胞凋亡率降低(P<0.05)。结论EPO能抑制大鼠TBI后神经细胞的凋亡,具有神经保护作用,其机制可能通过上调Bcl-2基因表达而实现。

Objective To study effects of Rh-EPO on neuronal apoptosis after traumatic brain injury in rats and explore the possible mechanism of neuroprotective effects and effects.Methods Fifty-five male adult Wistar rats,21 weeks old,were randomly divided into three groups as follow:sham operation group(n=5),TBI group(n=25)and EPO group(n=25).In the TBI group and EPO group,the rats were divided into 5 subgroups according to different time points,with 5 rats in each group.After each group was anesthetized,the sham operation group only cut the skin,bitten off the skull,and formed a bone window.The TBI group and the Rh-EPO group were made with the neurolab brain stereotaxic instrument and the beckman striker to make a rat model of severe craniocerebral injury.The Rh-EPO group was given Rh-EPO 5000 IU/kg intraperitoneally.Immunohistochemical SP(streptavidin-perosidase)method was used to detect the expression of Bcl-2,and flow cytometry was used to detect the apoptosis rate of nerve cells.Results Compared with the sham operation group,the apoptosis rate and Bcl-2 expression level in the TBI group were significantly increased(P<0.01);compared with the TBI group,Bcl-2 expression increased and the nerve cell apoptosis rate decreased in the Rh-EPO group(P<0.05).Conclusion EPO can inhibit neuronal apoptosis after TBI in rats.The mechanism may be achieved by up-regulating the expression of Bcl-2 gene.