布洛芬对淀粉样β蛋白片段1~40引起的大鼠海马p38 MAP激酶信号传导通路及半胱氨酸天冬氨酸蛋白酶级联的影响(英文)

Effects of ibuprofen on amyloid β-protein fragment 1-40-induced p38 MAP kinase signal pathway and caspase cascades in rat hippocampus in vivo

目的研究布洛芬对淀粉样β蛋白片段1-40 (Aβ1-40)所致大鼠海马损伤的保护作用及作用机制。方法大鼠ig给予布洛芬15 mg.kg-1,连续应用3周,脑室内一次性注射Aβ1-40(5μL,1 mmol.L-1),注射后6h快速取海马CA1区,Western免疫印迹法观察磷酸化丝裂原激活的蛋白激酶的激酶3/6(MKK3/MKK6)、磷酸化丝裂原激活的蛋白激酶p38(p38 MAP激酶)、磷酸化MAPK活化的蛋白激酶2(MAPKAPK2)、磷酸化热休克蛋白p27(Hsp27)、半胱氨酸天冬氨酸蛋白酶(caspase)9, 3,7以及ADP-核糖聚合酶(PARP)的蛋白表达水平的改变。结果脑室内注射Aβ1-40可引起海马CA1区磷酸化的MKK3/MKK6和磷酸化p38 MAP激酶表达明显增加,但可使磷酸化MAPKAPK2和磷酸化的Hsp27表达降低,这些改变伴随有caspase级联的激活。此外,也发现Aβ1-40可使海马CA1区完整的PARP蛋白表达明显减少,而劈切PARP(分子量为89 ku)表达明显增加。布洛芬可明显对抗Aβ1-40引起的磷酸化的MKK3/MKK6和磷酸化p38 MAP激酶表达增加,上调磷酸化MAPKAPK2和磷酸化的Hsp27表达水平,同时抑制Aβ1-40引起的caspase级联激活和PARP的劈切。结论布洛芬通过抑制Aβ1-40引起的磷酸化的MKK3/MKK6和磷酸化p38 MAP激酶表达,明显增加以及上调磷酸化的Hsp27表达水平,对抗Aβ1-40引起的海马的神经细胞损伤。

AIM To observe the neuroprotective effect and protective mechanisms of ibuprofen on amyloid β- protein fragment 1 - 40 （ Aβ1-40 ） -induced neurotoxicity in rat hippocampus. METHODS Rats were given ibuprofen （15 mg·kg^-1 daily, ig） for 3 weeks prior to icv single dose of Aβ1-40（5 μL, 1 mmol·L^-1）. Six hours after Aβ1-40 injection, Western blotting was used to determine the expressions of phospho-MAP kinase kinase （MKK） 3/MKK6, phospho-p38 MAP kinase, phospho-MAP kinase activating protein kinase 2 （ MAPKAPK2 ）, heat-shock protein 27 （ Hsp27 ）, procaspase 9, 3, and 7 cleavage, and poly （ ADPribose） polymerase （PARP） cleavage in hippocampal CA1 region. RESULTS Intraeerebroventricular injection of Aβ1-40 induced an increase in phosphorylated MKK3/MKK6 and p38 MAP kinase expressions in hippocampal CA1. These increases, in combination with reduced phospho-MAPKAPK2 and phospho-Hsp27 expressions, mediated Aβ1-40-induced the activation of caspases cascades. Ibuprofen （ 15 mg·kg^-1 · d^-1, 3 weeks） significantly prevented Aβ1-40-induced increases in phosphorylated MKK3/MKK6 and p38 MAP kinase expressions. In addition, Aβ1 -4o-induced decreases in phosphorylated MAPKAPK2 and Hsp27 expressions were abrogated by ibuprofen. Aβ1-40-induced changes in activation of caspases cascades were inhibited by ibuprofen. CONCLUSION Ibuprofen prevents Aβ1-40-induced neurotoxicity through suppres- sion of phosphorylated MKK3/MKK6 and p38 MAP kinase expressions and the up-regulation of phospho- Hsp27 expression.