血红蛋白氧载体通过蛋白激酶B信号通路抑制细胞凋亡减轻蛛网膜下腔出血后早期脑损伤

Hemoglobin-based oxygen carriers attenuate early brain injury after subarachnoid hemorrhage by inhibiting apoptosis via protein kinase B signaling pathway

目的探讨血红蛋白氧载体(HBOCs)对蛛网膜下腔出血(SAH)后早期脑损伤的保护作用及机制。方法采用血管内穿孔法制SAH模型。将成年雄性Sprague-Dawley大鼠(贵州医科大学实验动物中心)按随机数字表法分为假手术(Sham)组、SAH组和HBOC组,每组15只。HBOC组术后立即经股静脉输注15 ml/kg HBOCs,SAH组大鼠输注等体积乳酸林格氏液。术后24 h行SAH评分、神经功能评分及脑含水量的测定。采用尼氏染色和原位末端转移酶标记(TUNEL)检测神经元损伤及细胞凋亡。利用蛋白免疫印迹法检测蛋白激酶B(Akt)通路蛋白及凋亡相关蛋白的表达。组间比较采用t检验。结果SAH组神经功能评分低于Sham组和HBOC组(14.97±1.70比17.80±0.32,t=6.363,P<0.05;14.97±1.70比16.33±1.44,t=2.383,P<0.05)。SAH组细胞凋亡率高于Sham组和HBOC组[(26.66±6.01)%比(3.90±1.83)%,t=14.030,P<0.05;(26.66±6.01)%比(11.30±4.26)%,t=8.075,P<0.05]。SAH组磷酸化Akt(p-Akt)/Akt比值低于Sham组和HBOC组(0.51±0.10比0.97±0.09,t=5.936,P<0.05;0.51±0.10比0.86±0.17,t=3.088,P<0.05)。结论HBOCs通过激活Akt信号通路抑制细胞凋亡,减轻SAH后早期脑损伤。

Objective To investigate the protective effect and mechanism of hemoglobin-based ox-ygen carriers(HBOCs)in early brain injury after subarachnoid hemorrhage(SAH).Methods The SAH model was made by intravascular perforation method.Adult male Sprague-Dawley rats were divided into Sham surgery(Sham)group,SAH group and HBOC group with 15 rats in each group according to the ran-dom number table method.Rats in HBOC group were infused with 15 ml/kg HBOCs via femoral vein im-mediately after operation,while those in SAH group were infused with an equal volume of lactated Ringer's solution.SAH score,neurological function score and brain water content were measured after 24 h of sur-gery.Neuronal damage and apoptosis were detected by Nissl staining and Terminal-deoxynucleoitidyl trans-ferase mediated nick end labeling(TUNEL).The expression of protein kinase B(Akt)pathway proteins and apoptosis-related proteins was detected using Western blotting.The t-test was used for comparison be-tween groups.Results The score of neurological function in SAH group was lower than that in Sham group and HB0C group(14.97±1.70 vs.17.80±0.32,t=6.363,P<0.05;14.97±1.70 vs.16.33±1.44,t=2.383,P<0.05).The apoptosis rate in SAH group was higher than that in Sham group and HB0C group[(26.66±6.01)%vs.(3.90±1.83)%,t=14.030,P<0.05;(26.66±6.01)%vs.(11.30±4.26)%,t=8.075,P<0.05].The ratio of phosphorylated Akt(p-Akt)/Akt in SAH group was lower than that in Sham group and HB0C group(0.51±0.10 vs.0.97±0.09,t=5.936,P<0.05;0.51±0.10 vs.0.86±0.17,t=3.088,P<0.05).Conclusion HB0Cs inhibit apoptosis and reduce early brain injury after SAH by activating the Akt signaling pathway.