热休克蛋白70抑制大鼠颅脑损伤诱生型一氧化氮合酶mRNA的表达

目的 探讨热休克蛋白７０（ＨＳＰ７０）对大鼠感染性脑损伤（感脑）诱生型一氧化氮合酶（ｉＮＯＳ）的表达及一氧化氮（ＮＯ）合成的影响。方法 将大鼠７２只随机分为正常对照组、感染性脑损伤组和热休克处理组，每组又ｈ共３个时间点。采用百日咳菌液通过左颈内动脉注入制成大鼠感染性脑损伤模型，用Ｗｅｓｔｅｒｎ印迹杂交技术检测各组各时间点的ＨＳＰ７０的表达，同时用原位杂交方法检测各组ｉＮＯＳｍＲＮＡ的表达及Ｇｒｉｅｓｓ法测定各组的ＮＯ含量的变化。结果 Ｗｅｓｔｅｒｎ印迹杂交分析结果表明，大鼠感脑各组及正常组有一定量的ＨＳＰ７０表达，而热休克处理组的ＨＳＰ７０的量明显高于感脑组（Ｐ〈０．０１）。原位杂交结果提示ｉＮＯＳ在感脑的大脑皮质神经细胞４、８、２４ｈ开始表达，可见明显的杂交信号，而休克处理组仅有少量的阳性颗粒。ＮＯ含量在感脑

Heat shock protein 70 inhibited inducible nitric oxide synthase gene expression in infectious cerebral injury in rat

Objective To study the effects of heat shock protein 70 (HSP70) on inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) synthesis in infectious cerebral injury in rat. Methods The infectious cerebral injury model was developed by injection of Pertussis Bacilli (PB) suspension via the left internal carotid artery. A total of 72 rats were divided randomly into 3 groups: normal saline control group (NS group), infection cerebral injury group (PB group) and HSP70 pretreatment group (HSP group). The animals were decapitated at 4 h, 8 h and 24 h after injection of PB or NS. HSP70 expression in brain tissue was detected by using Western blot analysis. iNOS mRNA expression in brain tissue was determined by using in situ hybridization method and NO in the brain homogenate was determined by using Griess method. Results Western blot analysis showed HSP70 in brain tissue elevated after heat shock response (HSR), whereas the level of HSP70 in the HSP group was significantly higher than in the PB group ( P <0.01). The signals of iNOS mRNA expression were observed in NS group, PB group and HSP group at 4th h. Hybridization signals in the PB group were significantly stronger than those in the HSP group at 8th h and 24th h. Similarly, the concentration of NO in the PB group was significantly increased, while decreased in the HSP group ( P <0.01). Conclusion The HSR might inhibit iNOS mRNA expression and the increase of NO, which might be associated with the induction of HSP70 synthesis in brain tissue, suggesting that HSP70 may be protective against infectious cerebral injury. [