Essential role of mitogen-activated protein kinase pathways in protease activated receptor 2-mediated nitric-oxide production from rat primary astrocytes
Essential role of mitogen-activated protein kinase pathways in protease activated receptor 2-mediated nitric-oxide production from rat primary astrocytes
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DOI：
10.1016/j.niox.2009.05.007
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发表时间：
2009-09-15
影响因子：
3.9
通讯作者：
Ko, Kwang Ho
中科院分区：
文献类型：
--
作者：
Park, Gyu Hwan;Jeon, Se Jin;Ko, Kwang Ho
蛋白酶激活受体（PAR）通过传递凝血酶和胰蛋白酶等蛋白水解酶的信号，在神经炎症等脑功能调节中发挥重要作用。我们和其他人报道了该家族的成员PAR-2被胰蛋白酶激活，胰蛋白酶对神经生理过程的参与越来越明显，并且参与神经炎症过程，包括星形胶质细胞的形态变化。在这项研究中，我们研究了 PAR-2 在大鼠原代星形胶质细胞产生一氧化氮 (NO) 中的作用。 PAR-2激动剂胰蛋白酶的治疗以剂量依赖性方式增加NO产生，这是通过诱导型一氧化氮合酶的诱导介导的。胰蛋白酶介导的 NO 产生被 PAR-2 激动剂肽模拟，并被药理学 PAR-2 拮抗剂肽或 siRNA 介导的 PAR-2 表达抑制所减少，这表明 PAR-2 在此过程中的关键作用。 PAR-2 产生的 NO 被 PKC 激活剂 PMA 模拟，并被蛋白激酶 C (PKC) 抑制剂 Go6976 减弱。 PAR-2 刺激激活丝裂原激活蛋白激酶 (MAPK) 的三种亚型：细胞外信号调节激酶 (ERK)、c-Jun N 末端激酶 (JNK) 和 p38 MAPK。 PAR-2 产生的 NO 可以通过抑制 ERK、p38 和 JNK 通路而被阻断。 PAR-2 刺激还激活核因子 kappa B (NF-kappa B) DNA 结合和转录活性以及 I kappa B α 磷酸化。 NF-κ B 通路抑制剂抑制 PAR-2 介导的 NO 产生。此外，MAPK 途径的抑制剂可阻止 NF-kappa B 报告基因构建体的转录激活。这些结果表明，星形胶质细胞中 PAR-2 激活介导的 NO 产生是通过 MAPK 激活以及 NF-κ B 途径转导的。 (C) 2009 Elsevier Inc. 保留所有权利。
Protease-activated receptors (PARs) play important roles in the regulation of brain function such as neuro-inflammation by transmitting the signal from proteolytic enzymes such as thrombin and trypsin. We and others have reported that a member of the family, PAR-2 is activated by trypsin, whose involvement in the neurophysiological process is increasingly evident, and is involved in the neuroinflammatory processes including morphological changes of astrocytes. In this study, we investigated the role of PAR-2 in the production of nitric oxide (NO) in rat primary astrocytes. Treatment of PAR-2 agonist trypsin increased NO production in a dose-dependent manner, which was mediated by the induction of inducible nitric-oxide synthase. The trypsin-mediated production of NO was mimicked by PAR-2 agonist peptide and reduced by either pharmacological PAR-2 antagonist peptide or by siRNA-mediated inhibition of PAR-2 expression, which suggests the critical role of PAR-2 in this process. NO production by PAR-2 was mimicked by PMA, a PKC activator, and was attenuated by Go6976, a protein kinase C (PKC) inhibitor. PAR-2 stimulation activated three subtypes of mitogen-activated protein kinases (MAPKs): extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38 MAPK. NO production by PAR-2 was blocked by inhibition of ERK, p38, and JNK pathways. PAR-2 stimulation also activated nuclear factor-kappa B (NF-kappa B) DNA binding and transcriptional activity as well as I kappa B alpha phosphorylation. Inhibitors of NF-kappa B pathway inhibited PAR-2-mediated NO production. In addition, inhibitors of MAPK pathways prevented transcriptional activation of NF-kappa B reporter constructs. These results suggest that PAR-2 activation-mediated NO production in astrocytes is transduced by the activation of MAPKs followed by NF-kappa B pathways. (C) 2009 Elsevier Inc. All rights reserved.