Therapeutic targeting of MUC5B in a novel ferret model of idiopathic pulmonary fibrosis

项目摘要 特发性肺纤维化(IPF)是一种无法治愈的慢性间质性肺疾病 以纤维组织堆积为特征的。发展IPF的一个主要风险因素是 在呼吸粘蛋白的启动子中通常发现功能获得SNP(Rs35705950)， MUC5B。然而，MUC5B在IPF发生中的作用机制尚不清楚。小鼠 动物模型已经阐明了肺纤维化的一些基本过程，但它们 未能概括人类疾病的主要特征，并在 确定阻止或逆转疾病进展的治疗方法，可能是因为它们效果不佳 适合复制粘液和MUC5B的影响。 这突显了对1)代表表型的动物模型的迫切需要 和包括持续性纤维化在内的人IPF的机制特征；2)改进的 了解分子机制，包括与MUC5B的遗传关联 过度表达及其与疾病发病机制的联系；3)鉴定， 基于这些知识开发和评估新的治疗靶点。使用一个 与人类相似的肺生理和细胞生物学，包括MUC5B和其他粘液蛋白， 我们用雪貂建立了一种新的博莱霉素暴露模型。博莱霉素暴露 雪貂表现出人类疾病的特征，包括持续性的肺纤维化 富含胶原纤维的疾病；富含MUC5B的蜂窝状囊肿；成纤维细胞病灶； 气道重塑表现为远端气道间隙“近似化”的特征。 基于这些数据，我们的主要假设是MUC5B的高表达 促进异常修复机制以传播纤维化，代表治疗靶点 这可以在雪貂身上建模。在目标1中，我们将使用遗传和药理学方法来 检测MUC5B表达增加和减少对纤维化肺损伤和修复的影响 作为模型表型的验证。在目标2中，我们将确定烟雾暴露(a MUC5B表达的有效刺激物和IPF的危险因素)使雪貂倾向于进行性 纤维化和加重疾病的严重程度。在目标3中，我们将确定MUC5B是否具有治疗作用 MUC5B特异性反义寡核苷酸治疗肺纤维化的靶点 降低MUC5B的表达或一种使MUC5B蛋白正常化的新型合成生物聚合物 病理生理呼吸道的结构和功能。目标是开发一种IPF模型，该模型 提供了新的机会来确定MUC5B表达如何在IPF发病机制中起作用 并对MUC5B导向治疗进行评价，为IPF研究提供决定性的进展。

Project Summary Idiopathic Pulmonary Fibrosis (IPF) is an incurable, chronic, interstitial lung disease characterized by the accumulation of fibrotic tissue. A major risk factor for developing IPF is a commonly found gain-of-function SNP (rs35705950) in the promoter for the respiratory mucin, MUC5B. However, the mechanistic role of MUC5B in developing IPF remains unknown. Murine animal models have elucidated some fundamental processes of lung fibrosis, but they have failed to recapitulate key features of the human disease and have been unsuccessful in identifying therapies that halt or reverse disease progression, likely because they are poorly suited to replicate the impact of mucus and MUC5B. This highlights the critical need for 1) an animal model that represents the phenotypic and mechanistic features of human IPF, including sustained fibrosis; 2) an improved understanding of molecular mechanisms, including the genetic association with MUC5B overexpression and the connection to disease pathogenesis; and 3) the identification, development and evaluation of novel therapeutic targets based on this knowledge. With a similar lung physiology and cell biology to humans, including Muc5b and other mucus proteins, we have developed a novel bleomycin exposure model using ferrets. Bleomycin exposed ferrets exhibit hallmarks of the human condition including persistent, sustained fibrotic lung disease with collagen-rich fibrosis; Muc5b rich honeycomb cysts; fibroblastic foci; and prominent airway remodeling displaying characteristic ‘proximalization’ of the distal airway spaces. Based on these data, our overarching hypothesis is that heightened Muc5b expression promotes aberrant repair mechanisms to propagate fibrosis, representing a therapeutic target that can be modeled in ferrets. In Aim 1 we will use genetic and pharmacological approaches to test the effects of increased and reduced Muc5b expression on fibrotic lung injury and repair, serving as a validation of model phenotype. In Aim 2 we will determine if smoke exposure (a potent stimulator of Muc5b expression and risk factor for IPF) predisposes ferrets to progressive fibrosis and worsens disease severity. In Aim 3 we will determine if Muc5b is a therapeutic target for pulmonary fibrosis by administering Muc5b-specific antisense oligonucleotides to reduce Muc5b expression or a novel synthetic biopolymer that normalizes Muc5b protein structure and function in pathophysiologic airways. The goal is to develop a model of IPF that provides novel opportunities to define how Muc5b expression contributes to IPF pathogenesis and evaluate Muc5b-directed therapy, providing a definitive advance for IPF research.