P38通路对帕金森病小鼠模型黑质环氧合酶-2、半胱氨酸蛋白酶-3表达的影响

摘要

目的 研究P38MAPK通路在1-甲基-4-苯基-1,2,3,6四氢吡啶(MPTP)所致亚急性帕金森病(PD)小鼠模型中对黑质环氧合酶-2(COX-2)、半胱氨酸蛋向酶-3(caspase-3)表达调控作用.方法 采用MPTP制备PD小鼠模型,观察行为学、免疫组化和免疫蛋白印记法观察小鼠黑质酪氨酸羟化酶(TH)、COX-2、caspase-3和磷酸化P38MAPK(P-P38MAPK)的变化,及给予P38MAPK抑制剂SB203580后对上述变化的影响.结果 模型7 d组小鼠出现典型的PD样症状,黑质区TH阳性神经元和蛋白水平分别下降约65%和75%(P<0.01);模型3 d组小鼠黑质区COX-2、P-P38MAPK、caspase-3阳性细胞数及蛋白水平显著增加.TH阳性神经元明显丢失;经P38MAPK抑制剂SB203580处理后,上述变化均显著减轻(P<0.01).结论 在MPTP所致亚急性小鼠PD模型中,P38MAPK通路对黑质区炎症与凋亡可能有重要调控作用,SB203580对PD小鼠具有一定神经保护作用.%Objective To investigate the effect of p38 mitogen-activated protein kinase (p38MAPK) on the expression of COX-2 and caspase-3 in the substania nigra (SN) of mice with MPTP-induced Parkinson disease (PD). Methods C57BL/CN mice were treated with MPTP to prepare a subacute PD model, and their behavioral changes following the treatment were observed. Immunohistochemistry and Western blotting were performed to detect the expression of tyrosine hydroxylase (TH), COX-2 and phosphorylation of P38MAPK in the SN and their changes following treatment with SB203580, a specific inhibitor of P38MAPK. Results The 7-day model group showed typical symptoms of PD with decrements of TH-positive neurons and TH protein level in the SN of the midbrain by about 65% and 75%, respectively (P<0.01). In the 3-day model group, the COX-2-, caspase-3- and phosphorylated P38MAPK-immunoreactive cells and their protein levels in the SN increased markedly with obvious loss of TH-positive neurons. Administration of SB203580 obviously lessened the above changes (P<0.0l). Conclusion P38MAPK regulates the inflammation and apoptosis in the SN of the mouse model of subacute PD, and SB203580 may provide some neuroprotective effect.