Genetic and Epigenetic Changes in MUC5B and Fibrosing Interstitial Lung Disease

描述(由申请人提供)： 摘要/摘要：这项拟议的研究建立在我们最近的观察基础上，即MUC5B启动子的常见多态性和吸烟与家族性间质性肺炎(FIP)和特发性肺纤维化(IPF)的发生密切相关。我们先前发现，在有2个IIP病例的家庭中，吸烟对FIP的发生有很大的影响。最近，利用连锁、精细定位和关联，我们发现MUC5B启动子区域(Rs35705950)存在一个常见的多态性，它与家族性间质性肺炎(FIP)(P=1.2x10-15)和特发性肺纤维化(IPF)(P=2.5x10-37)相关；该等位基因杂合子和纯合子的患病优势比分别为6.8(95%CI3.9~12.0)和2 0.8(95%CI3.8~113.7)和9.0(95%CI 6.2~13.1)和2 1.8(95%CI 5.1~93.5)。此外，MUC5B基因在肺纤维化患者肺组织中的表达是非肺纤维化患者的14.1倍(P=0.0001)，MUC5B基因启动子的变异等位基因与肺组织中MUC5B基因的表达上调有关(37.4倍；P=0.0003)，MUC5B蛋白在肺纤维化的病理病变中表达。在这项提案中，我们计划重点研究MUC5B、香烟烟雾和几种类型的纤维化间质性肺病(FIRD)的遗传和表观遗传变异，以确定为什么只有一些具有MUC5B启动子多态性的人会患上肺纤维化。尽管相当一部分FIP或IPF受试者携带MUC5B启动子SNP的罕见等位基因(59%的FIP和60-67%的IPF)，但大约1/3的FIP或IPF受试者携带MUC5B启动子SNP的野生型。此外，患有这种常见SNP的普通人群中的大多数人(存在于19%-20%的对照中)不会发展为肺纤维化。我们还发现，无论MUC5B启动子SNP如何，IPF患者肺组织中MUC5B基因的表达均升高，提示MUC5B过度表达是IPF发病的共同机制。由于其他人已报道MUC5B的表达受到MUC5B启动子甲基化的强烈影响，因此推测MUC5B启动子的甲基化缺失可能会增强MUC5B的表达，并影响那些未携带MUC5B启动子SNP的罕见等位基因的肺纤维化患者的MUC5B肺纤维化的发展。或者，超甲基化变体Marks可能会保护那些带有MUC5B启动子SNP的人不会发生IPF。推动这项研究的总体概念是，由遗传、表观遗传或环境因素引起的MUC5B过度表达纤维化会增加ILD和发展成纤维间质肺疾病的风险。因此，我们假设ExMpUreCs5sBion MUC5B基因变异(除了rs35705950)、MUC5B启动子的甲基化变化和/或香烟烟雾暴露影响MUC5B的表达，并与香烟的纤维化间质性肺疾病(FIRD)的发生有关。右边的烟雾暴露数字说明了我们研究这一假说的方法。目标1目标2目标3目标3目标3

DESCRIPTION (provided by applicant): Summary/Abstract: The proposed research builds on our recent observations that a common polymorphism in the promoter of MUC5B and cigarette smoke are strongly associated with the development of both familial interstitial pneumonia (FIP) and idiopathic pulmonary fibrosis (IPF). We have previously found that within families with e 2 cases of IIP, the development of FIP is strongly influenced by cigarette smoking. More recently, using linkage, fine mapping, and association, we have discovered a common polymorphism in the promoter region of MUC5B (rs35705950) that is associated with both familial interstitial pneumonia (FIP) (P=1.2x10-15) and idiopathic pulmonary fibrosis (IPF) (P=2.5x10-37); odds ratios of disease for subjects heterozygous and homozygous for the rarer allele of this SNP were 6.8 (95% CI 3.9-12.0) and 20.8 (95% CI 3.8-113.7) for FIP, and 9.0 (95% CI 6.2-13.1) and 21.8 (95% CI 5.1-93.5) for IPF. Moreover, MUC5B gene expression in the lung was 14.1 fold higher in IPF affected subjects versus unaffected subjects (P=0.0001), the variant promoter allele of MUC5B was associated with upregulation in lung MUC5B gene expression among unaffected (but not affected) subjects (37.4-fold; P=0.0003), and MUC5B protein was expressed in pathologic lesions of IPF. In this proposal, we plan to focus on genetic and epigenetic variants of MUC5B, cigarette smoke, and several types of fibrosing interstitial lung disease (fILD) to determine why only some individuals with the MUC5B promoter polymorphism develop pulmonary fibrosis. Although a substantial portion of subjects with FIP or IPF carry the rare allele of the MUC5B promoter SNP (59% of FIP and 60-67% of IPF), approximately 1/3 of subjects with either FIP or IPF are wild type for the MUC5B promoter SNP. Moreover, most individuals in the general population with this common SNP (present in 19-20% of controls) do not develop pulmonary fibrosis. We have also found that MUC5B gene expression in the lung of IPF affected subjects was elevated irrespective of the MUC5B promoter SNP, suggesting MUC5B overexpression is a common mechanism in the pathogenesis of IPF. Since others have reported that expression of MUC5B is strongly influenced by methylation of the MUC5B promoter, it is logical to speculate that loss of methylation in the MUC5B promoter may enhance MUC5B expression and influence the development of MUC5B MUC5B pulmonary fibrosis in those subjects with pulmonary fibrosis that do not carry Gene Methylation the rare allele of the MUC5B promoter SNP. Alternatively, hypermethylation Variants Marks may protect those with the MUC5B promoter SNP from developing IPF. The overall concept driving the proposed research is that MUC5B overexpression Fibrosing caused by either genetic, epigenetic, or environment factors enhances the ILD and risk of developing fibrosing interstitial lung disease. Thus, we hypothesize ExMpUreCs5sBion that gene variants in MUC5B (in addition to rs35705950), methylation changes in the promoter of MUC5B, and/or cigarette smoke exposure affect the expression of MUC5B and are associated with the Cigarette development of fibrosing interstitial lung disease (fILD). The figure on Smoke Exposure the right illustrates our approach to study this hypothesis. Aim 1 Aim 2 Aim 3 Aim 3 Aim 3