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 一种导致肺动脉狭窄的不明原因的疾病 引起高肺血压的脉管系统通常导致心脏 失败目前，对细胞和分子生物学的了解很少。 PPH的基础。通常，提高cAMP和cGMP的信号机制 在肺脉管系统中允许维持低压、高压 灌注环境。据文献记载， 大电导，钙和电压激活钾（BKca）通道是 在调节肺动脉压方面的首要作用， BKca通道的抑制与以下发展有关： 肺动脉高压肺动脉高压膜片钳研究的初步数据 动脉平滑肌细胞（PASM）的小鹿头巾大鼠（FHR），一个公认的 肺动脉高压动物模型，表明cAMP，一种激活剂， cAMP依赖性蛋白激酶（PKA），通过 cGMP依赖性蛋白激酶（PKG）的“交叉激活”。与此相反， 蛋白激酶C（PKC）可引起肺血管收缩， FHR PASM中的BKca通道，但激活Sprague-Dawley中的BKca通道 （对照）大鼠。因此，拟议研究的假设是， cAMP依赖性血管扩张剂通过开放BKca通道舒张肺动脉 通过刺激PKG的活性， FHR中PKC的激活可抑制这种作用。这一假设将由以下人员进行检验： 采用最先进的电生理学、血管 收缩和生物化学/分子生物学来确定：1） cAMP依赖性血管扩张剂对体外肺动脉的影响，2） cAMP升高剂对来自单个细胞的全细胞和单通道K+电流的影响 从肺动脉分离的肌细胞，3）cAMP依赖性“交叉激活” 4）PKC对BKca通道活性的作用，以及是否有一个 PKG和PKC之间的直接相互作用对BKca通道的调节。长 这项研究的长期目标是了解cAMP升高剂 通过非内皮依赖性机制引起肺动脉血管舒张。 相信这些研究会对小说的发展起到一定的推动作用 有助于降低相关发病率和死亡率的治疗剂 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.