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病 其特征在于纤维组织的积聚。发生IPF的主要风险因素是 呼吸道粘蛋白启动子中常见的功能获得性SNP（rs35705950）， MUC5B。然而，MUC 5 B在发展IPF中的机制作用仍然未知。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关键特征， 确定阻止或逆转疾病进展的疗法，可能是因为它们很难 适合于复制粘液和MUC 5 B的影响。 这突出了对1）代表表型的动物模型的迫切需要， 和机制特征，包括持续的纤维化; 2）改善的 了解分子机制，包括与MUC 5 B的遗传关联 过表达和与疾病发病机制的联系;和3）鉴定， 基于这些知识开发和评价新的治疗靶点。与 与人类相似的肺生理学和细胞生物学，包括Muc 5 b和其他粘液蛋白， 我们开发了一种使用雪貂的新型博来霉素暴露模型。博莱霉素暴露 雪貂表现出人类疾病的特征，包括持续的，持续的肺纤维化， 富含胶原纤维化的疾病;富含Muc 5 b的蜂窝囊肿;成纤维细胞灶;和突出 气道重塑显示远端气道空间的特征性“近端化”。 基于这些数据，我们的总体假设是，Muc 5 b表达增加 促进异常修复机制以传播纤维化，代表治疗靶点 可以在雪貂身上模仿。在目标1中，我们将使用遗传和药理学方法， 测试增加和减少的Muc 5 b表达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 Muc 5 b表达的有效刺激物和IPF的风险因子）使雪貂易于进行性 纤维化和纤维化疾病的严重程度。在目标3中，我们将确定Muc 5 b是否是一种治疗药物， 通过施用Muc 5 b特异性反义寡核苷酸靶向肺纤维化， 降低Muc 5 b表达或使Muc 5 b蛋白正常化的新型合成生物聚合物 病理生理气道的结构和功能。目标是开发一个IPF模型， 为确定Muc 5 b表达如何促进IPF发病机制提供了新的机会 并评估Muc 5 b导向治疗，为IPF研究提供明确的进展。

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.