Regulation of phosphodiesterases and cAMP signaling during the host-pathogen interaction in the pulmonary endothelium

肺内皮宿主-病原体相互作用过程中磷酸二酯酶和 cAMP 信号传导的调节

• 批准号: 9901604
• 负责人: Wito H Richter
• 金额: $ 37.82万
• 依托单位: UNIVERSITY OF SOUTH ALABAMA
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9901604
• 关键词: Ablation; Adrenergic Agents; Adrenergic Receptor; Adult Respiratory Distress Syndrome; Agonist; Animal Model; Bacterial Infections; Bacterial exotoxin; Cell physiology; Clinical; Clinical Trials; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclic GMP; Cyclic Nucleotides; Data; Development; Edema; Endothelial Cells; Endothelium; Enzymes; Exotoxins; Failure; Family; Flagellin; Functional disorder; Genes; Genetic study; Health; Human; Impairment; Individual; Inflammation Mediators; Isoenzymes; Libraries; Lung; Lung infections; Mediating; Morbidity - disease rate; Nausea; Nosocomial pneumonia; Outcome; Pathway interactions; Patient-Focused Outcomes; Patients; Pharmacology; Phosphorylation; Physiological; Play; Pneumonia; Post-Translational Protein Processing; Pre-Clinical Model; Prevalence; Protein Isoforms; Proteins; Pseudomonas aeruginosa; Pseudomonas aeruginosa infection; Pyrimidine; Rattus; Regulation; Respiratory physiology; Role; Safety; Sepsis; Signal Transduction; Sterility; Testing; Therapeutic; Therapeutic Effect; Treatment Efficacy; Type III Secretion System Pathway; Virulence; Virulence Factors; Vomiting; cell growth regulation; desensitization; experimental study; improved; in vivo Model; inflammatory lung disease; inhibitor/antagonist; lung injury; mortality; novel strategies; pathogen; phosphodiesterase IV; phosphoric diester hydrolase; prevent; protective effect; side effect

PROJECT SUMMARY/ABSTRACT Acute respiratory distress syndrome (ARDS) is an inflammatory lung disease associated with high morbidity/mortality and limited treatment options. A breakdown of pulmonary endothelial barrier function, leading to edema and impaired lung function, is a hallmark of ARDS. It is well established that stimulation of cAMP synthesis, such as with β-adrenoceptor agonists, enhances endothelial barrier function and is protective in preclinical models of sterile lung injury such as upon LPS administration. However, clinical trials probing the utility of β-agonists in ARDS have failed and the reasons remain unclear. Cyclic nucleotide phosphodiesterases (PDEs), the enzymes that degrade and inactivate cAMP, play a critical role in the regulation of cellular cAMP levels, the subcellular compartmentalization of these signals, and hence endothelial cell functions. Our preliminary data indicate that a single Type-4 PDE isoform, PDE4D, contributes the predominant portion of cAMP-hydrolytic capacity in the pulmonary endothelium and is tightly regulated under physiologic conditions. P.aeruginosa (PA) is a common cause of nosocomial pneumonia that can progress to sepsis and ARDS. We observed that during the host-pathogen interaction, distinct PA virulence factors induce PDE4D activation, resulting in a suppression and dysregulation of endothelial cAMP signals. Specifically, the bacterial exotoxin cyclase ExoY promotes a PKA-mediated phosphorylation and activation of PDE4D that alters endothelial cAMP signaling. In addition, PA infection can induce a PKA-independent, but type-3 secretion system- and flagellin-dependent PDE4D regulation that results in activation and subcellular relocalization of the enzyme. With this proposal, we will define the pathways by which PA virulence factors alter PDE4D functions and its contribution to endothelial barrier disruption and lung injury. We will test the idea that PA-induced PDE4D activation correlates with health outcomes in patients with PA-associated ARDS, and that, conversely, inhibition of PDE4 is endothelial barrier protective. We will test the idea that aberrant PDE4 activation limits the therapeutic efficacy of β-agonists in settings of PA-lung infection as well as other causes of ARDS. The PDE4 family comprises four genes and non-selective PDE4 inhibitors have established therapeutic effects in preclinical models of ARDS, but also induce side effects, such as emesis and nausea, that limit their clinical utility. Given the unique and non-overlapping physiological and pathophysiological roles of each PDE4 isoform, targeting individual PDE4 proteins can serve to dissect the therapeutically beneficial from the side effects of the PAN-PDE4 inhibitors available to date. To this end, we will determine whether selective ablation of PDE4D is protective in ex vivo and in vivo models of PA-lung injury, paving the way for development of PDE4D-selective inhibitors as ARDS therapeutics with an improved safety profile compared to the non- selective PDE4 inhibitors available to date.

项目总结/摘要 急性呼吸窘迫综合征（ARDS）是一种与高血压相关的炎症性肺部疾病， 发病率/死亡率和有限的治疗选择。肺内皮屏障功能的破坏， 导致水肿和肺功能受损是ARDS的标志。众所周知，刺激 cAMP合成（例如使用β肾上腺素受体激动剂）可增强内皮屏障功能并具有保护作用 在无菌肺损伤的临床前模型中，例如在LPS施用后。然而，临床试验探索 β受体激动剂在成人呼吸窘迫综合征中的应用失败了，原因尚不清楚。环核苷酸 磷酸二酯酶（PDE），降解和分解cAMP的酶，在细胞内起关键作用。 细胞cAMP水平的调节，这些信号的亚细胞区室化，因此内皮细胞 细胞功能。我们的初步数据表明，单一的4型PDE亚型PDE 4D贡献了 cAMP水解能力的主要部分在肺内皮细胞中，并在 生理条件。铜绿假单胞菌（PA）是医院获得性肺炎的常见原因，可进展为 败血症和ARDS。我们观察到，在宿主-病原体相互作用过程中，不同的PA毒力因子诱导 PDE 4D活化，导致内皮cAMP信号的抑制和失调。具体而言是 细菌外毒素环化酶ExoY促进PKA介导的磷酸化和PDE 4D的活化， 改变内皮cAMP信号传导。此外，PA感染可诱导PKA非依赖性，但3型 分泌系统和鞭毛蛋白依赖性PDE 4D调节，导致活化和亚细胞 酶的重新定位。通过这一提议，我们将确定PA毒力因子 改变PDE 4D功能及其对内皮屏障破坏和肺损伤的作用。我们将测试这个想法 PA诱导的PDE 4D活化与PA相关ARDS患者的健康结局相关， 相反，抑制PDE 4是内皮屏障保护。我们将验证异常的PDE 4 激活限制了β-激动剂在PA-肺感染以及其他原因的情况下的治疗效果。 ARDS。PDE 4家族包括四个基因，并且非选择性PDE 4抑制剂已经建立了治疗作用。 在ARDS临床前模型中，这不仅会产生副作用，而且还会引起副作用，如呕吐和恶心，这限制了它们的治疗效果。 临床应用鉴于每种PDE的生理和病理生理作用独特且不重叠4 靶向单个PDE 4蛋白的同种型可以从侧面剖析治疗上有益的 PAN-PDE 4抑制剂的效果。为此，我们将确定是否选择性消融 PDE 4D在PA-肺损伤的离体和体内模型中具有保护作用，为开发 PDE 4D选择性抑制剂作为ARDS治疗剂，与非PDE 4D选择性抑制剂相比具有改善的安全性特征。 选择性PDE 4抑制剂。