Role of Epac1 in the Pathogenesis of Pulmonary Fibrosis

项目摘要 这个建议的总体目标是描述由cAMP直接激活的交换蛋白的作用 （Epac 1）在特发性肺纤维化（IPF）疾病中的作用。IPF的特征是进行性瘢痕形成和纤维化 导致危及生命的并发症，如呼吸衰竭。不幸的是， 治愈IPF和我们的老龄化世界人口需要绝大多数新的治疗靶点和策略 来治疗这种致命疾病的患者 大多数关于纤维化的研究都集中在增加cAMP，通过增加cAMP来抑制成纤维细胞增殖和分化。 然而，PKA通路既不调节Epac 1的表达，也不影响Epac 1对IPF的作用， 病理生理过程已明确定义。因此，通过具体的方法来指导研究是很有趣的。 在IPF中独立于PKA调节Epac酶的作用。最近，化合物AM-001已经 已被鉴定和表征为一种新的和有效的Epac 1药理学抑制剂。AM-001选择性 抑制Epac 1催化活性并显示心脏保护特性。这些发现反映了评估 Epac 1及其特异性抑制剂AM-001在肺纤维化（PF）疾病中的关键作用。我们的初步 研究显示Epac 1的表达在来自IPF患者的肺组织中显著增加， 成纤维细胞和博来霉素（BLM）攻击的小鼠。此外，Epac 1缺陷小鼠 保护免受BLM诱导的肺损伤和纤维化。此外，Epac 1的敲低和抑制 AM-001抑制正常和IPF成纤维细胞增殖和促纤维化标志物TGFβ的表达 和白细胞介素-6（IL-6）。此外，AM-001在BLM诱导的PF中显著降低体内肺纤维化 小鼠模型RNA测序数据分析显示IPF促纤维化基因特征的关键组分 在AM-001处理的NHLF细胞中。基于这些数据，我们的总体假设是Epac 1是一个重要的调节因子， Epac 1可能作为AM-001潜在的治疗靶点 PF疾病。在本提案中，我们将通过测试以下具体目标来扩展这些初步结果： 具体目的1：确定Epac 1在人和小鼠PF中的表达模式。 具体目标2：明确Epac 1在成纤维细胞活化中的作用机制。 具体目的3：评估新型Epac 1特异性抑制剂AM-001在小鼠模型中的有效性。 肺纤维化总的来说，拟议的研究将有助于增加我们对Epac 1在肺中作用的理解。 与老年PF发病机制相关的重塑，并可能导致新的潜在靶点的鉴定， 阻止这种致命疾病的进展。

PROJECT SUMMARY The overall objective of this proposal is to delineate the role of the exchange protein directly activated by cAMP (Epac1) in idiopathic pulmonary fibrosis (IPF) disease. IPF is characterized by progressive scarring and fibrosis of the lungs that results in life-threatening complications such as respiratory failure. Unfortunately, there is no cure for IPF, and our aging world population requires a vast majority of new therapeutic targets and strategies for treating patients with this fatal disease. Most studies in fibrosis focused on increased cAMP to inhibit fibroblast proliferation and differentiation through the PKA pathway, however, neither the regulation of the expression nor the contribution of Epac1 to IPF pathophysiological processes are well defined. Thus, it is interesting to direct the research by specifically regulating the actions of the Epac enzymes independently of PKA in IPF. Recently, the compound AM-001 has been identified and characterized as a novel and potent Epac1 pharmacological inhibitor. AM-001 selectively inhibits Epac1 catalytic activity and displays cardioprotective properties. Such findings reflect the need to assess the key role of Epac1 and its specific inhibitor AM-001 in pulmonary fibrosis (PF) disease. Our preliminary studies show that the expression of Epac1 is significantly increased in lung tissue from IPF patients, IPF diseased fibroblasts, and bleomycin (BLM)-challenged mice compared to controls. Furthermore, Epac1 deficiency mice are protected against BLM induced-lung injury and fibrosis. Furthermore, the knockdown and inhibition of Epac1 by AM-001 attenuate normal and IPF fibroblasts proliferation and the expression of pro-fibrotic markers, TGFβ and interleukin-6 (IL-6). In addition, AM-001 significantly decreases lung fibrosis in vivo in the BLM-induced PF mouse model. RNA sequencing data analyses show key components of the pro-fibrotic genes signature of IPF in AM-001-treated NHLF cells. Based on these data our overall hypothesis is that Epac1 is an important regulator of the fibroblast's pathological state in PF and that Epac1 can serve as a potential therapeutic target by AM-001 for PF disease. In this proposal, we will extend these preliminary findings by testing the following specific aims: Specific Aim 1: To define the expression pattern of Epac1 in humans and mice with PF. Specific Aim 2: To define the mechanisms of Epac1 function in fibroblast activation. Specific Aim 3: To evaluate the effectiveness of a novel Epac1-specific inhibitor AM-001 in a mouse model of pulmonary fibrosis. Collectively, the proposed studies will help increase our understanding of Epac1 role in lung remodeling associated with aged-PF pathogenesis and may lead to the identification of new potential targets to block the progression of this deadly disease.