Objective To investigate the impact of recombinant human erythropoietin (rhEPO) pretreatment on liver ischemia-reperfusion injury (IRI) in rats and explore the molecular mechanism. Methods Thirty male Sprague-Dawley(SD)rats were randomly divided into three groups equally, including Sham, control and rhEPO groups. Rats in rhEPO group were treated with rhEPO (5 000 U/kg) 1 hour before IR induction while sham and control groups were pretreated with saline. 70% liver IR rat model was established in control and rhEPO groups except for sham group. Rat liver tissues and serum were harvested for hematoxylin and eosin (HE) staining, Western Blot, qPCR and enzyme linked immunosorbent assay(ELISA) assay, respectively. Liver histology, transaminases (AST, ALT), pro-inflammation cytokines (TNF-α, IL-6, IL-1β) and PI3K/AKT signaling were investigated. Results Distinct liver injury was observed with a higher histological damage score and the release of AST and ALT in serum after 70% tissue IR process. rhEPO significantly decreased the pathologic changes of liver and the release of AST and ALT in serum〔AST(U/L):582.0±52.5 vs. 245.0±31.7 ; ALT(U/L):388.0±39.6 vs. 166±24.3,both P＜0.05〕. The expression of p-p85 and p-AKT were increased in rhEPO group compared to control group. TNF-α, IL-6 and IL-1β mRNA levels were demonstrated to ascend after IR but lower expression was observed in rhEPO group. Remarkable IRI-induced secretion of TNF-α, IL-6 and IL-1β proteins in serum was verified but rhEPO inhibited the secretion 〔TNF-α(pg/ml):425.0±31.2 vs. 227.0±19.7 ;IL-6(pg/ml):353.0±26.4 vs. 189.0±16.3 ;IL-1β (pg/ml):511.0±39.6 vs. 328.0±23.2 ,all P＜0.05)〕. Conclusion rhEPO pretreatment can reduce the release of pro-inflammation cytokines and protect liver from IRI in rats through enhanced activation of PI3K/AKT signaling.%目的 探讨重组人促红细胞生成素(rhEPO)对大鼠肝脏缺血/再灌注损伤(IRI)的保护作用和机制.方法 选取健康雄性Sprague-Dawley(SD)大鼠30只,随机均分为实验组(rhEPO组)、对照组及假手术组.rhEPO组术前1小时通过尾静脉注射5 000 U/kg的rhEPO,然后建立大鼠70%肝脏IRI模型.苏木素-伊红(HE)染色观察肝脏组织学变化;生化仪测定血清中天冬氨酸转氨酶(AST)和丙氨酸转氨酶(ALT)的释放量;蛋白免疫印迹试验(Western Blot)检测PI3K/AKT蛋白磷酸化水平;qPCR测定炎性细胞因子〔肿瘤坏死因子(TNF-α)、白细胞介素(IL-6和IL-1β)〕 mRNA的表达;酶联免疫吸附试验(ELISA)测定血清中TNF-α、IL-6和IL-1β浓度.结果 对照组有明显的肝组织损伤,血清中AST和ALT释放量均增加,而rhEPO组肝组织损伤程度较轻,转氨酶水平低于对照组〔AST(U/L):582.0±52.5比245.0±31.7 ; ALT(U/L):388.0±39.6比166.0±24.3, 均P＜0.05〕.蛋白检测发现rhEPO组p-p85和p-AKT的表达显著增加,明显高于对照组.qPCR提示rhEPO组炎性因子TNF-α、IL-6和IL-1β mRNA表达明显低于对照组.ELISA亦证实rhEPO组血清中TNF-α、IL-6和IL-1β分泌低于对照组〔TNF-α (pg/ml):425.0±31.2 比 227.0±19.7 ;IL-6(pg/ml):353.0±26.4 比 189.0±16.3 ;IL-1β(pg/ml):511.0±39.6比328.0±23.2 , 均P＜0.05〕.结论 rhEPO预处理能抑制大鼠肝脏IRI时炎性因子释放,保护肝组织,其机制可能与PI3K/AKT信号的进一步活化有关.
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