Non-canonical WNT signaling in emphysema and lung regeneration

项目总结/摘要 该提案的目标是确定“规范到非规范”的WNT信号转换如何有助于 肺气肿和受损的肺再生。肺气肿是一种慢性肺部疾病，影响超过400万人 在美国的人和治疗，停止进展或扭转疾病是不可用的。气肿是 特征在于实质肺组织的进行性和永久性破坏，特别是功能性的 肺泡上皮重要的是，远端肺激活自我修复机制的内源性能力是 肺气肿的缺陷远端肺上皮祖细胞（DLEP）群体可能有助于肺 在人类肺部已经发现了修复，这就提出了为什么以及哪些再生途径的问题。 和/或细胞在肺气肿中沉默。经典的WNT/β-catenin信号转导最近被确定为一种新的信号转导途径。 潜在的再生途径与肺气肿活动减少。值得注意的是，非经典WNT信号传导， 不依赖于β-catenin，可抑制经典的WNT/β-catenin信号传导。我们最近报告说 肺气肿中的非典型WNT信号传导，代表第一次典型到非典型WNT信号 已经证明这种转变会导致慢性肺病。在人类和实验性肺气肿中， 非典型WNT配体WNT 5A增加。抑制WNT 5A恢复经典WNT/β-连环蛋白 在体外肺泡上皮细胞中的信号传导和在体内两种肺气肿模型中减弱的组织破坏。 在这里，我们的目的是确定WNT 5A的抑制作用的分子机制和功能后果 对DLEP中典型WNT/β-catenin信号传导和肺气肿中肺再生的影响。我们假设非- 由WNT受体的疾病特异性和细胞特异性表达介导的典型WNT信号传导充当“制动器”， 内源性WNT/β-连环蛋白驱动的肺再生。目标1：确定是否和如何 WNT/β-连环蛋白反应性（WNT）-DLEP可能在肺气肿中发生变化，以及WNT 5A如何影响WNT-DLEP， 使用肺类器官测定，辅以健康肺和肺气肿肺的体内和离体研究 组织中目的2：鉴定DLEP上介导WNT 5A信号传导的非经典WNT受体，并测试其在DLEP中的表达。 假设这些是恢复WNT信号平衡从而减弱WNT的潜在治疗靶点， 体外和体内实验性肺气肿。目标3：确定是否将规范转换为非规范 WNT信号转移加速了体内实验性肺气肿的肺再生，并导致肺组织中的 离体来源于患者的3D-LTC中的COPD/肺气肿生物标志物。因此，该提案将：（1）提供深入的 了解新的WNT/β-catenin反应性DLEP亚群，并成为第一个阐明 肺气肿中DLEP功能的非经典WNT信号传导; 2）鉴定肺气肿中细胞特异性WNT受体， 健康和患病肺，这是肺病理学中基本上未探索的区域，对于开发新的 治疗靶点;以及3）从患者来源的组织中获得重要的原理验证数据，以进一步铺平 未来肺气肿转化和临床研究的方向。

PROJECT SUMMARY/ABSTRACT The goal of this proposal is to determine how the ‘canonical to non-canonical’ WNT signaling shift contributes to emphysema and impaired lung regeneration. Emphysema is a chronic lung disease affecting over 4 million people in the US and therapies that stop the progression or reverse disease are not available. Emphysema is characterized by progressive and permanent destruction of parenchymal lung tissue, in particular functional alveolar epithelium. Importantly, the endogenous ability of the distal lung to activate self-repair mechanisms is defective in emphysema. Distal lung epithelial progenitor cell (DLEP) populations that might contribute to lung repair have been identified in the human lung, which raises the question why and which regenerative pathways and/or cells are silenced in emphysema. Canonical WNT/β-catenin signaling has been recently identified as a potential regenerative pathway with reduced activity in emphysema. Notably, non-canonical WNT signaling, which is β-catenin independent, can inhibit canonical WNT/β-catenin signaling. We recently reported increased non-canonical WNT signaling in emphysema, representing the first time a canonical to non-canonical WNT signal shift has been demonstrated to contribute to a chronic lung disease. In human and experimental emphysema, the non-canonical WNT ligand WNT5A is increased. Inhibition of WNT5A restored canonical WNT/β-catenin signaling in alveolar epithelial cells in vitro and attenuated tissue destruction in two emphysema models in vivo. Here, we aim to identify the molecular mechanisms and functional consequence of the inhibitory effect of WNT5A on canonical WNT/β-catenin signaling in DLEP and lung regeneration in emphysema. We hypothesize that non- canonical WNT signaling, mediated by disease- and cell-specific expression of WNT receptors, acts as a “brake” for endogenous WNT/β-catenin-driven lung regeneration in emphysema. Aim 1: determine whether and how WNT/β-catenin-responsive (WNT)-DLEP might change in emphysema and how WNT5A impacts WNT-DLEPs, using lung organoid assays complemented by in vivo and ex vivo studies in healthy and emphysematous lung tissues. Aim 2: identify the non-canonical WNT receptor(s) on DLEP that mediates WNT5A signaling and test the hypothesis that these are potential therapeutic targets to restore WNT signal balance and thereby attenuate experimental emphysema in vitro and in vivo. Aim 3: determine whether reversing the canonical to non-canonical WNT signal shift accelerates lung regeneration in experimental emphysema in vivo and leads to a decrease in COPD/emphysema biomarkers in patient-derived 3D-LTCs ex vivo. This proposal will thus 1) provide in-depth knowledge about novel WNT/β-catenin-responsive DLEP subpopulations and be the first to elucidate the role of non-canonical WNT signaling for DLEP function in emphysema; 2) identify cell-specific WNT receptors in the healthy and diseased lung, an area largely unexplored in lung pathologies and critical for development of novel therapeutic targets; and 3) result in significant proof-of-principle data from patient-derived tissue to further pave the way for future translational and clinical investigations in emphysema.