重组人促红细胞生成素对大鼠急性脑缺血脑组织中肿瘤坏死因子-α基质金属蛋白酶-9和血管生成素-2表达的影响

Effects of rhEPO on expression of TNF-α, MMP-9 and Ang-2 in brain tissues of rats with acute cerebral ischemia

目的探讨重组人促红细胞生成素(rhEPO)对大鼠急性局灶性脑缺血损伤的神经保护作用及其机制。方法健康雄性SD大鼠54只随机分为假手术组、模型组和rhEPO治疗组。采用线栓法制作大鼠永久性局灶性脑缺血(pMCAO)模型。rhEPO治疗组在缺血2h后腹腔注射rhEPO4000U/kg,模型组和假手术组在等时间点给予等量的生理盐水。缺血24h后断头取脑分别用干湿质量法计算脑组织含水量,2,3,5-氯化三苯基四氮唑(TTC)法测量脑梗死体积,免疫组织化学方法测定肿瘤坏死因子-α(TNF-α)、基质金属蛋白酶-9(MMP-9)、血管生成素-2(Ang-2)的表达。结果 rhEPO治疗组与模型组相比,脑组织含水量减少,脑梗死体积减小,TNF-α和MMP-9的表达降低,而Ang-2的表达较模型组升高(P<0.05)。结论 rhEPO对大鼠急性脑缺血有一定的神经保护作用,其机制可能是通过降低TNF-α、MMP-9的活性和促进Ang-2的表达来实现的。

Objective To explore the neuroprotective effects and mechanism of recombinant human erythropoietin （rhEPO） on acute focal cerebral ischemic injury in Sprague-Dawley rats. Methods Fifty-four healthy male SD rats were randomized into sham-operated group, model group and rhEPO treatment group. Suture method was used to establish permanent middle cerebral artery occlusion （pMCAO） model. rhEPO treatment group underwent intraperitoneal injection of 4000 U/kg rhEPO after ischemia for 2 hours, whereas model group and sham-operated group were given equivalent saline at the same time. All rats were decapitated after ischemia for 24 hours, and water contents in the brain tissues were measured by dry-wet weight method. The size of infarction was measured by TTC staining （2,3,5- triphenyl tetrazolium chloride）, and the expression of tumor necrosis factor （TNF-α）, matrix metalloproteinase-9 （MMP-9） and angiopoietin-2 （Ang-2） were detected by immunohistochemistry. Results Compared with the model group, rhEPO treatment group showed diminished brain tissue water contents, smaller infarction size and lowered expressions of TNF-α and MMP-9 but elevated expression of Ang-2 （P0.05）. Conclusion Recombinant human EPO may be neuroprotective against acute cerebral ischemia in rats, probably by inhibiting the activities of TNF-α and MMP-9 and enhancing expression of Ang-2.