Role of Muc5b in Honeycomb Cyst Formation

项目摘要 这项提案的总体科学目标是建立在我们在MUC5B相关的特发性 肺纤维化（IPF），了解肺纤维化的基本机制。IPF是一种毁灭性的 这种疾病每年在全世界夺走500万人的生命。其特征在于进行性肺纤维化， 形成微观蜂窝（HC）囊肿。虽然最近已经有一些治疗方法， IPF的治疗受限于我们对其病理生物学的理解。我们发现， MUC5B基因上游3kb多态性是IPF发生的最强危险因素。在 在小鼠的初步实验中，我们证明了Muc5b的过表达导致了 博莱霉素和流感引起的纤维化。然而，Muc5b过度表达而不伴有肺损伤， 足以引起纤维化。IPF中的基因表达分析表明MUC5B与IPF的发病相关。 表达HC。同样，我们和其他人已经发现HC含有大量MUC5B蛋白。一 最近的一份出版物指出，小鼠在流感损伤的情况下会产生HC样囊肿， 其形成依赖于Notch发育途径。Notch信号也被证明是 对IPF中HC的形成很重要。我们发现，小鼠体内流感相关的HC样囊肿含有 在人肺上皮细胞系中，Notch抑制显著降低MUC5B 表情然而，NOTCH和MUC5B在IPF中的相互作用完全未知。鉴于明显的 Notch在Muc5b和HC样囊肿表达中的作用，以及Muc5b在人类和 在小鼠纤维化模型中，我们假设Notch调节肺损伤修复并促进肺纤维化。 纤维化通过下游Muc5b表达。在本提案的目标1中，我将为Notch确立一个角色， 肺纤维化和Muc5b表达通过测试Notch是否是必要的或足够的。在Aim中 2、我将评估Muc5b在纤维化中的必要性，并确定Muc5b对纤维化的影响是否与其对纤维化的影响有关。 上皮细胞固有的。这些目标解决了我们对IPF发病机制的认识存在的重大空白，特别是 这可能会导致新的治疗方法。在这个新项目中接受的培训将 提高我对分子生物学的理解，并与生物信息学的具体课程相结合，将 使我能够专注于间质性肺病的功能遗传学方法。

Project summary The overall scientific goal of this proposal is to build upon our findings in MUC5B-associated idiopathic pulmonary fibrosis (IPF) to understand the basic mechanisms of pulmonary fibrosis. IPF is a devastating disease that claims 5 million lives worldwide annually. It is characterized by progressive lung fibrosis and formation of microscopic honeycomb (HC) cysts. Although some therapies have recently become available, treatment of IPF is limited by our understanding of its pathobiology. We have found that a gain-of-function polymorphism 3kb upstream of the MUC5B gene is the strongest risk factor for development of IPF. In preliminary experiments in mice, we demonstrate that overexpression of Muc5b leads to an enhancement of fibrosis provoked by bleomycin and influenza. However, overexpression of Muc5b without lung injury is not sufficient to provoke fibrosis. Gene expression analysis in IPF has demonstrated an association of MUC5B expression with HC. Likewise, we and others, have discovered that HCs contain significant MUC5B protein. A recent publication noted that mice develop HC-like cysts in the setting of influenza injury, and that cyst formation depends on the Notch developmental pathway. Notch signals have also been demonstrated to be important for HC formation in IPF. We have found that influenza-associated HC-like cysts in mice contain copious Muc5b, and in human lung epithelial cell lines Notch inhibition significantly reduces MUC5B expression. However, the interplay of NOTCH and MUC5B in IPF are completely unknown. Given the apparent role of Notch in the expression of Muc5b and HC-like cysts, and the characterized role of Muc5b in human and murine fibrosis models, we hypothesized that Notch modulates lung injury repair and promotes pulmonary fibrosis through downstream Muc5b expression. In Aim 1 of this proposal, I will establish a role for Notch in pulmonary fibrosis and Muc5b expression by testing whether Notch is necessary or sufficient for either. In Aim 2, I will evaluate the necessity of Muc5b in fibrosis, and determine whether effects of Muc5b on fibrosis are epithelial-cell intrinsic. These Aims address significant gaps in our knowledge of IPF pathogenesis, particularly where epithelia are concerned, and may lead to novel therapies. Training received during this novel project will enhance my understanding of molecular biology, and, paired with specific coursework in bioinformatics, will enable me to focus on functional genetic approaches to interstitial lung disease.