PKC Signaling in cAMP-Induced Pulmonary Vasodilation

描述(由申请人提供)：原发性肺动脉高压(PPH)是 一种原因不明的疾病，导致肺变窄 导致肺高压的血管系统通常导致心脏 失败了。目前，关于细胞和分子方面的知识很少。 PPH的基础。正常情况下，升高cAMP和cGMP的信号机制 在肺血管系统中允许维持低压力、高压力 灌流环境。有充分的证据表明， 大电导、钙和电压激活钾(BKCa)通道 最重要的是调节肺动脉压和 BKCa通道的抑制与糖尿病的发生有关 肺动脉高压。肺组织膜片钳研究的初步数据 公认的乳头鹿大鼠动脉平滑肌细胞(PASM) 肺动脉高压的动物模型表明，cAMP是一种 CAMP依赖的蛋白激酶(PKA)，通过 CGMP依赖的蛋白激酶(PKG)的“交叉激活”。相比之下， 蛋白激酶C(PKC)引起肺血管收缩，抑制 FHR PASM的BKCa通道，但激活SpragueDawley的BKCa通道 (对照)大鼠。因此，拟议研究的假设是 CAMP依赖的血管扩张剂通过开放BKCa通道松弛肺动脉 在肺动脉平滑肌中通过刺激PKG的活性，以及 激活PKC可抑制FHR的作用。这一假设将通过以下方式检验 使用最先进的电生理学、血管 收缩，以及生物化学/分子生物学来确定：1)影响 CAMP依赖的血管扩张剂对体外大鼠肺动脉的作用 CAMP升高剂对大鼠全细胞和单通道钾电流的影响 从肺动脉分离的心肌细胞，3)cAMP依赖的“交叉激活” 4)PKC在BKCa通道活性中的作用以及是否存在 PKG和PKC在BKCa通道调制中的直接相互作用。《长河》 这项拟议研究的长期目标是了解提升阵营的药物是如何 通过非内皮依赖性机制引起肺血管扩张。 相信这些研究将对小说的发展起到推动作用。 有助于降低相关发病率和死亡率的治疗药物 伴有PPH和其他肺血管疾病。

DESCRIPTION (provided by applicant): Primary Pulmonary Hypertension (PPH) is a disease of unknown origin that results in narrowing Of the pulmonary vasculature causing high pulmonary blood pressure often leading to heart failure. Currently there is little knowledge on the cellular and molecular foundation of PPH. Normally, signaling mechanisms which elevate cAMP and cGMP in the pulmonary vasculature allow for the maintenance of a low pressure, high perfusion environment. It is well documented that the activation of the large-conductance, calcium-and voltage-activated potassium (BKca) channel is of primary importance in the regulation of pulmonary arterial pressure and inhibition of the BKca channel has been implicated in the development of pulmonary hypertension. Preliminary data from patch-clamp studies in pulmonary arterial smooth muscle cells (PASM) of the fawn-hooded rat (FHR), a recognized animal model of pulmonary hypertension, suggests that cAMP, an activator of cAMP-dependent protein kinase (PKA), opens the BKca channel through "cross-activation" of the cGMP-dependent protein kinase (PKG). In contrast, protein kinase C (PKC) which causes pulmonary vasoconstriction, inhibits the BKca channel in FHR PASM, but activates the BKca channel in Sprague-Dawley (control) rats. Therefore, the hypothesis of the proposed studies is that cAMP-dependent vasodilators relax pulmonary arteries by opening BKca channels in pulmonary arterial smooth muscle by stimulating the activity of PKG, an effect inhibited by activation of PKC in FHR. This hypothesis will be tested by employing state-of-the-art techniques of electrophysiology, vascular contraction, and biochemistry/molecular biology to determine: 1) the effect of cAMP-dependent vasodilators on pulmonary arteries in vitro, 2) the effect of cAMP-elevating agents on whole-cell and single channel K+ currents from single myocytes isolated from pulmonary arteries, 3) cAMP-dependent "cross-activation" of PKG, and 4) the role of PKC on BKca channel activity and whether there is a direct interaction between PKG and PKC on BKca channel modulation. The long term goal of the proposed study is to understand how cAMP-elevating agents cause pulmonary arterial vasodilation by an endothelium-independent mechanism. It is believed that these studies will lead to the development of novel therapeutic agents that will help reduce the morbidity and mortality associated with PPH and other pulmonary vascular diseases.