摘要目的：探讨 PTEN 抑制剂 BPV 对脑缺血再灌注损伤大鼠的神经保护作用及其机制。方法利用雄性 Sprague-Dawley 大鼠建立大脑中动脉闭塞1 h再灌注模型,于再灌注时立刻腹腔注射BPV 溶液(0．2 mg/kg,1次/d)或等容积生理盐水。缺血再灌注第1、3、5和7天时进行神经功能缺损评分；第4天时氯化三苯基四氮唑染色评估脑梗死体积,酶联免疫吸附法测定皮质缺血周围区白细胞介素(interleukin, IL)-10和肿瘤坏死因子(tumor necrosis factor, TNF)-α水平,实时定量聚合酶链反应检测 PTEN mRNA 表达水平,蛋白质印迹法测定 PI3K、Akt 和 p-GSK-3β表达水平；第7天时应用Bielschowsky 银染色检测纹状体缺血周围区轴突分布,免疫组织化学染色检测髓鞘碱性蛋白(myelin basic protein, MBP)表达。结果缺血再灌注第4天时,BPV 组大鼠脑梗死体积[(32．27±1．71)%对(45．49±2．12)%；P <0．001]、皮质缺血周围区 TNF-α浓度[(134．17±10．38)pg/ml 对(264．17±24．84)pg/ml；P <0．001]和 PTEN mRNA 水平(1．19±0．08对2．50±0．06；P <0．001)均显著低于生理盐水组, IL-10浓度[(186．83±10．83)pg/ml 对(147．83±11．62)pg/ml； P <0．001]以及 PI3K (0．43±0．08对0．26±0．06； P =0．004)、 Akt (0．52±0．05对0．40±0．04； P =0．001)和 p-GSK-3β(0．75±0．08对0．38±0．06；P <0．001)表达水平均显著高于生理盐水组。缺血再灌注第7天时,BPV组大鼠神经功能缺损评分[(4．83±0．41)分对(6．33±0．52)分；P <0．001]显著低于生理盐水组,缺血周围区轴突密度[(35．51±2．45)%对(25．31±2．79)%；P <0．001]和 MBP 表达水平[(32．56±3．46)%对(27．81±4．18)%；P =0．037]均显著高于生理盐水组。结论 BPV 对大鼠脑缺血再灌注损伤具有神经保护作用,其机制可能与通过上调 PTEN 下游蛋白质 PI3K、Akt 和 p-GSK-3β表达来调节炎症介质和减轻炎性反应有关。

abstractsObjective To investigated the neuroprotective effect of PTEN inhibitor BPV on cerebral ischemia-reperfusion injury in rats and its mechanism. Methods Male Sprague-Dawley rats were used to induce a reperfusion model of middle cerebral artery occlusion for 1 h. During the reperfusion, the BPV solution (0. 2 mg/kg daily) or the equal volume of saline was injected intraperitonealy immediately. The neurological deficit scores were conducted at day 1, 3,5, and 7 after ischemia-reperfusion. At day 4, triphenyl tetrazolium chloride staining was used to assess cerebral infarction volume. Enzyme-linked immunosorbent assay was used to detect the levels of interleukin 10 (IL-10) and tumor necrosis factor α(TNF-α) in cortical ischemic border zones. Real-time quantitative polymerase chain reaction was used to detect the expression level of PTEN mRNA. Western blotting was used to detect the expression levels of PI3K, Akt, and p-GSK-3β. At day 7, Bielschowsky silver staining was used to detect the axonal distribution in the ischemic border zone of the striatum. Immunohistochemical staining was used to detect the expression of myelin basic protein (MBP). Results At day 4 after ischemia-reperfusion, the infarct volume (32. 27% ± 1. 71% vs. 45. 49% ± 2. 12% ; P < 0. 001), TNF-α concentration in the cortical ischemic border zones (134. 17 ± 10. 38 pg/ml vs. 264. 17 ± 24. 84 pg/ml; P < ), and PTEN mRNA level (1. 19 ± 0. 08 vs. 2. 50 ± 0. 06; P < 0. 001) in the rats of the BPV group were al significantly lower than those of the normal saline group. The IL-10 concentration (186. 83 ± 10. 83 pg/ml vs. 147. 83 ± 11. 62 pg/ml; P < 0. 001), and the expression levels of PI3K (0. 43 ± 0. 08 vs. 0. 26 ± 0. 06; P = 0. 004), Akt (0. 52 ± 0. 05 vs. 0. 40 ± 0. 04;P = 0. 001), and p-GSK-3β (0. 75 ± 0. 08 vs. 0. 38 ± 0. 06; P < 0. 001) were al significantly higher than those of the normal saline group. At day 7 after ischemia-reperfusion, the neurological deficit score (4. 83 ± 0. 41 vs. 6. 33 ± 0. 52; P < 0. 001) in the rats of the BPV group was significantly lower than that of the normal saline group. The axon densities in the ischemic border zones (35. 51% ± 2. 45% vs. 25. 31% ± 2. 79% ; P < 0. 001) and the expression level of MBP (32. 56% ± 3. 46% vs. 27. 81% ± 4. 18% ; P = 0. 037) were significantly higher than those of the normal saline group. Conclusions BPV has neuroprotective effect for cerebral ischemia-reperfusion injury in rats. Its mechanism may be associated with the up-regulation of PTEN downstream proteins PI3K, Akt and p-GSK-3β expression to regulate inflammatory mediators and reduce the inflammatory response.