Epigenomic Modulation of Cystic Fibrosis

描述(申请人提供)：囊性纤维化(CF)是一种遗传性的蛋白质稳态(蛋白质稳态)功能丧失的儿童疾病。囊性纤维化跨膜电导调节因子(F508CFTR)是一种多膜跨膜、cAMP调节的氯离子通道，主要由Phe 508缺失引起。内质网中？F508的错误折叠和有效降解是胞外途径的第一步，降低了蛋白质的稳定性，导致细胞表面电导丧失，肺功能早衰和寿命缩短。Cf是一大组错误折叠疾病的成员之一，包括儿童肺气肿、溶酶体储存缺陷、II型糖尿病和与衰老相关的蛋白质平衡缺陷的神经退行性病变。我们现在证明，通过用组蛋白脱乙酰酶(HDACi)抑制剂(HDACi)调节表观基因组，我们可以重新编程肺细胞环境，以实现F508合成、折叠、降解和运输导致细胞表面电导(功能)之间的生产性平衡。这种纠正事件发生在用临床批准的HDACi SaHA治疗从F纯合子患者(HBE-CF-(F/F))获得的原代人支气管上皮(HBE)细胞时，达到被认为对疾病具有纠正作用的细胞表面通道活性的水平。HDAC7的小干扰(Si)-RNA特异性敲除导致肺细胞电导的恢复，这表明只有HDAC活性的一部分调节CFTR的折叠、稳定、运输和功能。我们认为，Hvacs控制一个与蛋白调控有关的转录程序，以实现F508的折叠、稳定、运输和功能，从而对CF具有保护作用。在这项建议中，我们建议开发特定的小分子来抑制HDAC7的功能(目标1)，并探索HDAC7在CF生物学中的作用(目标2)。使用HDACi来化学调节连接的转录和蛋白质稳态环境，预计将对纠正人类错误折叠疾病产生很大影响。 公共卫生相关性：囊性纤维化(CF)是一种遗传性的儿童功能丧失疾病，由囊性纤维化跨膜电导调节因子(F508CFTR)突变引起，囊性纤维跨膜传导调节因子是肺部的一种关键氯通道。突变通道的错误折叠和降解会导致细胞表面电导的丧失，过早的肺衰竭和寿命的缩短。我们证明，通过调节细胞表观基因组(通过修改DNA组织来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来纠正疾病，证明通过一组新的药物对细胞蛋白质组成的药物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.