Natriuretic Peptides in Pulmonary Endothelial Cell Barrier Function

利钠肽在肺内皮细胞屏障功能中的作用

• 批准号: 7809486
• 负责人: JAMES Raymond KLINGER
• 金额: $ 27.58万
• 依托单位: RHODE ISLAND HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7809486
• 关键词: Acute; Acute Lung Injury; Adult Respiratory Distress Syndrome; Affect; Agonist; Alveolar; Attenuated; Blood Vessels; Blood capillaries; Brain; Capillary Endothelial Cell; Cells; Conflict (Psychology); Cyclic GMP; Cyclic GMP-Dependent Protein Kinases; Data; Dominant-Negative Mutation; Edema; Endothelial Cells; Event; Failure; Functional disorder; Gases; Goals; Guanosine Triphosphate Phosphohydrolases; Guanylate Cyclase; Heart Atrium; In Vitro; Inflammatory; Lead; Link; Liquid substance; Lung; Mediating; Monomeric GTP-Binding Proteins; Mus; Natriuretic Peptides; Pathway interactions; Peptide Receptor; Peptides; Permeability; Phosphodiesterase Inhibitors; Physiological; Play; Proteins; Pulmonary Edema; Receptor Signaling; Recovery; Respiratory physiology; Role; Severe Acute Respiratory Syndrome; Signal Pathway; Signal Transduction; Testing; Thrombin; Vascular Endothelial Cell; atrial natriuretic factor receptor A; capillary; inhibitor/antagonist; injured; interstitial; monolayer; protective effect; pulmonary artery endothelial cell; receptor; restoration; rho GTP-Binding Proteins; therapeutic development; therapeutic target

DESCRIPTION (provided by applicant): The aim of this proposal is to determine the receptor signaling pathways by which the natriuretic peptides (NP) modulate pulmonary microvascular endothelial cell (PMVEC) barrier function and pulmonary edema formation. Pulmonary edema is the primary cause of lung dysfunction in most cases of acute lung injury. Transudation of vascular fluid and protein from the pulmonary capillary lumen to the interstitial and alveolar space impairs gas exchange and initiates a cascade of inflammatory events that lead to acute respiratory distress syndrome. The NPs (atrial, ANP, brain, BNP, and C-type, CNP) play important physiologic roles in modulating vascular endothelial cell permeability. Numerous studies have documented their ability to reduce permeability of proximal pulmonary artery endothelial cells, however, the receptors and signal pathways responsible for this effect are not well defined and few studies have examined the effect of NPs on PMVECs, the cells that are responsible for regulating trans-pulmonary fluid flux. Recent studies in the applicant's lab have shown that the NPs differentially affect PMVEC barrier function and that the guanylyl cyclase- and non- guanylyl cyclase-linked receptors (NPR-A, NPR-C, respectively) have differing effects. The overall goal of this proposal is to identify the receptor-signaling pathways that mediate the inhibitory effects of the NPs on PMVEC barrier function. This proposal will test the hypotheses that NPs blunt thrombin-induced increases in PMVEC permeability via NPR-A by a cGMP/PKG pathway and facilitate restoration of PMVECs barrier dysfunction via NPR-C. In addition, the proposal hypothesizes that the inhibitory effects of the NPs on thrombin-induced increases in PMVEC permeability are mediated via downstream inhibition of the small GTPases RhoA, Rac1 and cdc42. The proposal aims to test these hypotheses by 1) examining the effect of NPs, phosphodiesterase inhibitors and PKG inhibitors on the permeability of PMVECs, 2) examining the effect of altered expression of NPR-A, NPR-C, PKG and the small GTPases on the ability of NPs to protect against thrombin-induced barrier dysfunction in vitro, and 3) examine the effect of NPs on pulmonary edema formation in mice with targeted disruption of NPR-A and NPR-C. Findings from these studies will further our understanding of cellular mechanism that modulate pulmonary edema formation and determine if the NPs and their receptors are potential therapeutic targets for acute lung injury.

描述（由申请人提供）：本提案的目的是确定利钠肽（NP）调节肺微血管内皮细胞（PMVEC）屏障功能和肺水肿形成的受体信号通路。在大多数急性肺损伤病例中，肺水肿是肺功能障碍的主要原因。血管液体和蛋白质从肺毛细血管腔转移到肺间质和肺泡间隙，损害气体交换，引发一系列炎症事件，导致急性呼吸窘迫综合征。NPs（心房、ANP、脑、BNP和c型CNP）在调节血管内皮细胞通透性中发挥重要的生理作用。许多研究已经证明它们能够降低近端肺动脉内皮细胞的通透性，然而，负责这种作用的受体和信号通路尚未得到很好的定义，很少有研究检查了NPs对PMVECs的影响，PMVECs负责调节经肺液体通量。申请人实验室最近的研究表明，NPs对PMVEC屏障功能的影响是不同的，观酰基环化酶连接受体和非观酰基环化酶连接受体（分别为NPR-A， NPR-C）具有不同的作用。本提案的总体目标是确定介导NPs对PMVEC屏障功能抑制作用的受体信号通路。该建议将验证NPs通过cGMP/PKG途径通过NPR-A抑制凝血酶诱导的PMVEC通透性增加的假设，并通过NPR-C促进PMVEC屏障功能障碍的恢复。此外，该建议假设NPs对凝血素诱导的PMVEC通透性增加的抑制作用是通过下游对小gtp酶RhoA， Rac1和cdc42的抑制介导的。为了验证这些假设，本研究将通过以下方法进行验证：1)检测NPs、磷酸二酯酶抑制剂和PKG抑制剂对pmvec通透性的影响；2)检测体外NPs、NPR-C、PKG和小gtpase表达改变对NPs抗凝血酶诱导的屏障功能障碍能力的影响；3)检测NPs对靶向破坏NPR-A和NPR-C小鼠肺水肿形成的影响。这些研究的发现将进一步加深我们对调节肺水肿形成的细胞机制的理解，并确定NPs及其受体是否是急性肺损伤的潜在治疗靶点。