吡格列酮对脑室注射脂多糖所致大鼠海马损伤的保护作用机制探讨  

Inhibitory effects of pioglitazone on LPS-induced neurotoxicity in rat hippocampus in vivo

作　　者：闫恩志[1] 范莹[1] 隋海娟[1] 刘卓[1] 刘婉珠[2] 金英[1] 

机构地区：[1]辽宁医学院药理学教研室,辽宁锦州121001 [2]辽宁医学院机能实验中心,辽宁锦州121001

出　　处：《中国药理学通报》2013年第6期859-862,共4页Chinese Pharmacological Bulletin

基　　金：辽宁省教育厅科学研究项目(No L2012310);辽宁省教育厅创新团队项目(No LT 2010064)

摘　　要：目的研究吡格列酮(Pio)对脂多糖(LPS)所致大鼠海马神经元损伤保护作用的信号传导机制。方法取SD大鼠40只,随机分为4组,每组10只,即生理盐水对照组,LPS组,LPS+Pio 40和80 mg.kg-1组。大鼠灌胃给予Pio24 h后,脑室注射LPS 5μl(1.0 mmol.L-1),生理盐水对照组注射等量生理盐水。脑室注射后继续给药7 d后,快速取海马CA1区,Western blot观察磷酸化的c-Jun氨基末端激酶1(JNK1)、c-Jun、Akt、p70S6K和Caspase-3表达,应用荧光免疫组织化学进行磷酸化JNK和OX-42双染,激光共聚焦显微镜观察磷酸化JNK的表达部位。结果 Western blot结果显示注射LPS后,与对照组相比海马CA1区磷酸化JNK1、c-Jun和Caspase-3表达水平明显增加(P<0.01),磷酸化Akt、p70S6K表达水平明显降低(P<0.01)。与LPS损伤组比较,Pio(40和80 mg.kg-1)能对抗LPS引起的海马CA1区磷酸化JNK1、c-Jun、Akt、p70S6K和Caspase-3表达的改变(P<0.01),激光共聚焦显微镜观察结果显示,脑室内注射LPS后小胶质细胞磷酸化的JNK表达明显增加。结论 Pio通过抑制JNK和Akt激酶信号传导通路的改变,对抗LPS引起的海马神经元损伤。Aim To observe the inhibitory effects of pi- oglitazone （ Pio ） on lipopolysaccharide （ LPS ） -induced neurotoxicity in rat hippocampus and its neuroprotec- rive mechanisms. Methods Forty Sprague-Dawley were randomly divided into four groups：control; LPS; LPS ＋ pioglitazone 40 mg . kg-1 ; LPS ＋ pioglitazone 80 mg . kg-1 Rats were given pioglitazone 24 h prior to intraeerebroventricular injection of LPS of a single dose of 5 μl （1 mmol . L-1）. The rats in control group were injected with saline of the same volume. All the rats were given DMSO or Pio for 7 d. Seven days af- ter injection, Western blot was used to determine the expression of p-JNK1, p-c-Jun, p-Akt, p-p70S6K and Caspase-3 in hippocampal CA1 region. Immunohisto- chemistry and double labeling immunofluorescenee combined with laser scanning confocal microscope were used to investigate the expression of p-JNK and 0X-42protein in hippocampal CA1 areas. Results Compared with normal control group, the protein levels of p- JNK1 ,p-c-Jun, and Caspase-3 in LPS treatment group were significantly increased ; the protein levels of p-Akt and p-pTOS6K in LPS treatment group were significant- ly decreased. The LPS-induced changes could be re- versed by Pio （ 40,80 mg . kg-1 ） treatment for 7 d. The result of p-JNK and OX-42 expressions examined by double labeling immunofluorescence combined with laser scanning confocal microscope showed that most of p-JNK immunoreactivity co-localized with microglia- speccific protein OX-42. Conclusion Pioglitazone prevents LPS-induced neurotoxicity through changing the expression of phosphorylated JNK and Akt signal pathway in hippocampal CA1 region.

关 键 词：吡格列酮 阿尔采末病 脂多糖 c-Jun氨基末端激 酶 Akt 细胞凋亡 

分 类 号：R-332[医药卫生] R322.81