小檗碱对局部脑缺血组织中HIF-1α表达的影响

目的 研究大鼠局部性脑缺血再灌注损伤时,小檗碱(BE)对缺氧诱导因子-1α(HIF-1α)表达及脑神经元凋亡的影响.方法 雄性SD大鼠随机分为假手术组、大脑中动脉阻塞再灌注组(MCAO/R组)、假性治疗组(DMSO组)、小檗碱10mg/kg治疗组(BE10组)、小檗碱20mg/kg治疗组(BE20组)、小檗碱40mg/kg治疗组(BE40组).治疗组在术前48h、24h及术后6h腹腔注射相应剂量药物,观察各组大鼠神经行为学缺陷;再灌注7d,TTC染色观察脑梗死体积变化;再灌注24h,制备脑组织切片分别作Nissl染色、免疫组织化学染色、TUNEL标记及免疫荧光双标记.结果 BE20、BE40组神经功能较MCAO/R组有明显改善(P＜0.05),但BE10组神经学评分与MCAO/R组比较,差异无统计学意义(P＞0.05).不同剂量BE治疗均可以减小梗死灶体积(P＜0.05),且呈现剂量依赖性.Nissl染色可见BE治疗组皮质神经元结构较清晰,胞体肿胀、核固缩、核溶解程度较模型组及假性治疗组明显减轻,淡染区域减小;免疫组织化学法观察到,BE组HIF-1α、Caspase-3、BNIP3、VEGF及TUNEL标记的阳性细胞数减少;免疫荧光双标记显示HIF-1α与BNIP3、Caspase-3及TUNEL阳性颗粒共表达于细胞中.结论 BE可能通过降低HIF-1α水平并下调其下游的BNIP3和VEGF的表达,从而减少凋亡因子Caspase-3的作用而发挥神经元保护作用.

EFFECT OF BERBERING ON HIF-1α EXPRESSION INDUCED BY FOCAL CEREBRAL ISCHEMIA IN RATS

Objective To investigate the effect of berbering on the expression of hypoxia inducible factor 1α (HIF-1α) and the neuronal apoptosis after focal cerebral ischemia. Methods Male SD rats were randomly divided into six groups: control (sham surgery), middle cerebral artery occlusion and reperfusion(MCAO/R), MCAO/R treated with vehicle(DMSO), MCAO/R treated with berbering at concentrations of 10mg/kg, 20mg/kg, 40mg/kg,respectively. Berbering of different doses was injected intraperitoneally at 24hours, 48hours before operation and 6hours after operation. We observed the neurological deficits in different groups. Rats were sacrificed at 7days for TTC staining and at 24hours for Nissl staining, immunohistochemical, double fluorescence labeling, TUNEL studies. Results Berbering improved neurological deficits(P<0.05) except at the concentration of 10mg/kg(P>0.05), reduced the infarct volume (P<0.05)dependent of different concentrations. Berbering inhibited the neuronal deformation shown by Nissl staining and reduced the expression of HIF-1α, activated Caspase-3, BNIP3 and VEGF detected by immunohistochemical staining. HIF-1α positive immunoreactive materials were colocalized with BNIP3,Caspase-3 and TUNEL staining inside neurons in the injured cerebral cortex expressed by double fluorescence labeling. Conclusion Berbering may play a neural protection effect by inhi