活化蛋白C通过降低炎症因子表达减轻大鼠缺血性脑损伤研究

Activated Protein C Alleviate Ischemic Brain Injury by Anti-inflammation

目的探讨活化蛋白C(activated protein C,APC)在炎症反应参与的缺血性脑损伤中是否有保护作用。方法采用雄性SD大鼠右侧大脑中动脉闭塞模型,缺血2 h后恢复再灌注。大鼠随机分为3组(假手术组、溶剂对照组、APC组),每组6~8只,在缺血后6 h假手术组、溶剂对照组经腹腔注射给予生理盐水(1 mL/kg)、APC组给予APC(2 mg/kg)。制模后24 h观察APC对大鼠脑缺血再灌注后神经功能评分、梗死体积和血脑屏障通透性及脑组织中核转录因子-κB(nuclear transcription factor-κB,NF-κB)p65、核因子κB抑制蛋白(inhibitor of nuclear transcription factor-κB,IκB)、炎症因子肿瘤坏死因子-α(tumor necrosis factorα,TNF-α)、白细胞介素-1β(interleukin-1β,IL-1β)蛋白表达的影响。结果与溶剂对照组相比,APC组缺血后72 h的神经功能评分改善、梗死体积减小、血脑屏障通透性降低;APC组的胞浆NF-κB p65和IκB蛋白表达增加,而胞核部分NF-κB p65表达减少;胞浆TNF-α和IL-1β蛋白明显降低,以上差异均具有统计学意义。结论APC能通过抑制NF-κB p65的活化和核易位,降低炎症因子TNF-α和IL-1β蛋白的水平,减轻血脑屏障损伤,对大鼠局灶性脑缺血再灌注具有神经保护作用。

Objective To explore whether activated protein C(APC)plays a protective role in ischemic brain injury.Methods The models of cerebral ischemia-reperfusion were performed by clipping right middle cerebral artery(MCA)of male SD rats and releasing MCA after 2 hours of ischemia.The rats were randomly divided into three groups:sham operation group,normal saline(NS)control group and APC group,with 6-8 rats in each group.After 6 hours of ischemia,the rats in sham operation group and control group were given NS(1 mL/kg)by intraperitoneal injection,and the rats in APC group were given APC(2 mg/kg).At 24 hours after clipping MCA,the neurological function scores,infarct volume and the permeability of blood-brain barrier(BBB),the expression of protein NF-κB p65 and IκB and inflammatory factors TNF-αand IL-1βin brain tissue were measured to analyze the effect of APC in cerebral ischemia.Results Compared to control group,the neurological function score significantly improved,the infarct volume and BBB permeability both reduced in APC group.Compared to control group,the expression of proteins NF-κB p65 and IκB in the cytoplasm increased,the expression of protein NF-κB p65 in cell nuclei decreased,and the levels of TNF-αand IL-1βin the cytoplasm significantly decreased in APC group.Conclusions APC can reduce the levels of inflammatory factors TNF-αand IL-1β,reduce BBB permeability by inhibiting the activation and nuclear translocation of NF-κB p65.APC plays aneuroprotective role in cerebral ischemia-reperfusion injure.