Epigenomic Modulation of Cystic Fibrosis

描述（由申请人提供）：囊性纤维化（CF）是一种遗传性蛋白质稳态功能丧失性儿童疾病。CF主要是由囊性纤维化跨膜传导调节因子（？F508 CFTR），一种跨多膜cAMP调节的氯离子通道。错误折叠和有效降解？内质网中的F508是胞吐途径的第一步，它降低了蛋白质的稳定性，导致细胞表面电导的丧失、过早的肺衰竭和寿命缩短。CF是一大组错误折叠疾病的成员，包括儿童肺气肿、溶酶体储存缺陷、II型糖尿病和与蛋白质稳态缺陷的衰老相关的神经退行性病理学。我们现在表明，通过调节表观基因组与组蛋白脱乙酰酶（HDAC）抑制剂（HDACi），我们可以重新编程肺细胞环境，以实现生产率之间的平衡？F508的合成、折叠、降解和运输导致细胞表面的传导（功能）。这种纠正事件发生在处理从？F纯合子患者（HBE-CF-（？）F/？F）与临床上批准的HDACi SAHA结合至被认为是疾病矫正的功能性细胞表面通道活性水平。通过HDAC 7的小干扰（si）-RNA的特异性敲低导致肺细胞中电导的恢复，表明仅HDAC活性的子集调节CFTR折叠、稳定性、运输和功能。我们认为，HVACs控制的转录程序，是连接到蛋白质，以实现折叠，稳定性，贩运和功能？F508可以保护CF。在这项提案中，我们建议开发特异性小分子来抑制HDAC 7功能（目标1），并探索HDAC 7在CF生物学中的作用（目标2）。使用HDACi化学调节相关的转录和蛋白质稳态环境预计对纠正人类错误折叠疾病具有高度影响。 公共卫生相关性：囊性纤维化（CF）是一种遗传性功能丧失性儿童疾病，由囊性纤维化跨膜传导调节因子（？F508 CFTR），肺中的关键氯离子通道。突变通道的错误折叠和降解导致细胞表面电导的丧失、过早肺衰竭和寿命缩短。我们表明，通过调节细胞表观基因组（通过修饰DNA组织控制细胞核中基因表达的事件），我们可以重新编程肺细胞环境以纠正疾病，这表明通过一组新药物对细胞蛋白质组成的药理学调节可以对纠正人类错误折叠疾病产生很大影响。

DESCRIPTION (provided by applicant): Cystic fibrosis (CF) is an inherited loss-of-function childhood disease in protein homeostasis (proteostasis). CF is caused principally by the Phe 508 deletion in the cystic fibrosis transmembrane conductance regulator (?F508 CFTR), a multi-membrane spanning, cAMP-regulated chloride channel. Misfolding and efficient degradation of ?F508 in the endoplasmic reticulum, the first step in the exocytic pathway, reduces the stability of the protein resulting in the loss of cell surface conductance, premature lung failure and shortened lifespan. CF is a member of a large group of misfolding diseases including childhood emphysema, lysosomal storage deficiencies, type II diabetes and neurodegenerative pathologies associated with aging that are defective in proteostasis. We now show that by modulating the epigenome with histone deacetylase (HDAC) inhibitors (HDACi), we can reprogram the lung cell environment to achieve a productive balance between the rate of ?F508 synthesis, folding, degradation and trafficking leading to conductance (function) at the cell surface. This corrective event occurs upon treatment of primary human bronchial epithelial (HBE) cells obtained from ?F homozygous patients (HBE-CF-(?F/?F) with the clinically approved HDACi SAHA to a level of functional cell surface channel activity that is considered corrective for disease. Specific knockdown by small interfering (si)-RNA of HDAC7 results in recovery of conductance in lung cells, suggesting that only a subset of HDAC activities modulates CFTR folding, stability, trafficking and function. We suggest that HVACs control a transcriptional program that is linked to proteostasis to achieve folding, stability, trafficking and function of ?F508 that can be protective for CF. In this proposal, we propose to develop specific small molecules to inhibit HDAC7 function (Aim 1) and to explore the role of HDAC7 in CF biology (Aim 2). Use of HDACi to chemically modulate linked transcriptional and protein homeostasis environments is anticipated to have high impact on correction of human misfolding disease. PUBLIC HEALTH RELEVANCE: Cystic fibrosis (CF) is an inherited loss-of-function childhood disease caused by mutation of the cystic fibrosis transmembrane conductance regulator (?F508 CFTR), a critical chloride channel in the lung. Misfolding and degradation of the mutant channel results in the loss of cell surface conductance, premature lung failure and shortened lifespan. We show that by modulating the cellular epigenome (events that control gene expression in the nucleus through modification of DNA organization), we can reprogram the lung cell environment to correct disease, demonstrating that pharmacological modulation of the protein composition of the cell through a novel group of drugs can have a high impact on correction of human misfolding disease.