Alves E S, Haidar A A, Quadros C D, Carvalho D S, Morgan D, Rocha M S, Curi R, Carpinelli A R, Hirata A E
Department of Physiology, Federal University of Sao Paulo-UNIFESP, São Paulo, Brazil.
Regul Pept. 2012 Apr 10;175(1-3):1-6. doi: 10.1016/j.regpep.2012.01.003. Epub 2012 Jan 25.
Angiotensin II (AII), the active component of the renin angiotensin system (RAS), plays a vital role in the regulation of physiological processes of the cardiovascular system, but also has autocrine and paracrine actions in various tissues and organs. Many studies have shown the existence of RAS in the pancreas of humans and rodents. The aim of this study was to evaluate potential signaling pathways mediated by AII in isolated pancreatic islets of rats. Phosphorylation of MAPKs (ERK1/2, JNK and p38MAPK), and the interaction between proteins JAK/STAT were evaluated. AII increased JAK2/STAT1 (42%) and JAK2/STAT3 (100%) interaction without altering the total content of JAK2. Analyzing the activation of MAPKs (ERK1/2, JNK and p38MAPK) in isolated pancreatic islets from rats we observed that AII rapidly (3 min) promoted a significant increase in the phosphorylation degree of these proteins after incubation with the hormone. Curiously JNK protein phosphorylation was inhibited by DPI, suggesting the involvement of NAD(P)H oxidase in the activation of protein.
血管紧张素 II（AII）是肾素血管紧张素系统（RAS）的活性成分，在心血管系统生理过程的调节中起着至关重要的作用，同时在各种组织和器官中也具有自分泌和旁分泌作用。许多研究表明，人类和啮齿动物的胰腺中存在RAS。本研究的目的是评估AII在大鼠分离胰岛中介导的潜在信号通路。评估了丝裂原活化蛋白激酶（MAPKs，即细胞外信号调节激酶1/2、应激活化蛋白激酶和p38丝裂原活化蛋白激酶）的磷酸化以及JAK/STAT蛋白之间的相互作用。AII增加了JAK2/STAT1（42%）和JAK2/STAT3（100%）的相互作用，而不改变JAK2的总含量。分析大鼠分离胰岛中MAPKs（ERK1/2、JNK和p38MAPK）的激活情况，我们观察到，与该激素孵育后，AII迅速（3分钟）促使这些蛋白的磷酸化程度显著增加。奇怪的是，JNK蛋白磷酸化受到二苯基碘鎓（DPI）的抑制，这表明NAD（P）H氧化酶参与了该蛋白的激活。
