Interstitial lung diseases (ILD) due to disturbed processing and function of the lipid transporter ABCA3 as a result of mutations in the ABCA3 gene

脂质转运体ABCA3在肺泡II型细胞板层体的生物形成和肺表面活性物质的产生中是不可或缺的。ABCA3基因突变导致的活性降低或缺失导致新生儿急性呼吸窘迫综合征和儿童和年轻人慢性间质性肺疾病。因此，治疗方法必须以增加肺中ABCA3活性为目标。我们建议资助的项目是研究调节正常和突变ABCA3生理功能的因素。我们计划研究决定ABCA3在片层体膜中数量的机制。其中包括蛋白质的转运和翻译后调节。我们研究的另一个重点是临床相关突变如何影响这些机制。此外，突变对ABCA3活性的影响将通过脂质组学和使用一种新的磷脂酰胆碱衍生物来分析，这种衍生物比目前使用的大多数化合物更接近天然底物。为了能够精确地分析突变效应，我们利用锌指核酸酶技术产生了ABCA3敲除细胞系。除体外研究外，我们计划分析ABCA3突变患者肺组织中ABCA3的数量和定位，从而建立体外数据与临床表型之间的联系。体外实验结果与ABCA3突变患者肺组织离体数据的相关性，将为旨在提高肺中ABCA3功能活性的治疗干预提供新的途径。从我们在此建议资助的项目中，我们期望对ABCA3的功能和调控，ABCA3突变引起的干扰以及纠正它们的新实验方法有新的见解。这些发现将促进ABCA3功能调节的新治疗方法。此外，对ABCA3细胞生物学的进一步了解也将有助于对abca家族中细胞生物学基本未知的其他成员得出结论。

The lipid transporter ABCA3 is indispensable for the biogenesis of lamellar bodies in alveolar type II cells and for the production of pulmonary surfactant. A reduced or missing activity of ABCA3 due to mutations causes acute respiratory distress syndrome in neonates and chronic interstitial lung disease in children and young adults. Therefore, therapeutic approaches must be aimed at increasing ABCA3 activity in the lung.The project we are suggesting for funding is dealing with factors regulating the physiological function of normal and mutant ABCA3. We plan to investigate the mechanisms that determine the amount of ABCA3 in the lamellar body membrane. Among these are the trafficking and posttranslational regulation of the protein. Another focus of our studies is the question how clinically relevant mutations affect these mechanisms. In addition, the effects of mutations on ABCA3 activity will be analyzed using lipidomics and also by the use of a new class of phosphatidylcholine derivatives that resemble the naturally occurring substrates more closely than most compounds that have been used so far. To be able to precisely analyze mutation effects we generate an ABCA3 knockout cell line using zinc-finger nuclease technology. In addition to in vitro studies, we plan to analyze the amount and localization of ABCA3 in lung tissue from patients with ABCA3 mutations, thereby establishing a link between in vitro data and clinical phenotype. The correlation of in vitro findings with ex vivo data from lung tissue of patients with ABCA3 mutations will facilitate new approaches for therapeutic interventions aimed at increasing functional activity of ABCA3 in the lung.From the project we suggest for funding herein we expect new insights into function and regulation of ABCA3, their disturbance as a result of ABCA3 mutations and new experimental approaches for their correction. These findings will facilitate new therapeutic approaches for the modulation of ABCA3 function. Moreover, an improved understanding of the cell biology of ABCA3 will also allow conclusions regarding other members of the ABCA-family whose cell biology is largely unknown.