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

脂类转运蛋白ABCA3对于肺泡II型细胞板层小体的生物发生和肺表面活性物质的产生是不可或缺的。由于突变导致的ABCA3活性降低或缺失会导致新生儿的急性呼吸窘迫综合征和儿童和年轻人的慢性间质性肺部疾病。因此，治疗方法必须以增加肺中ABCA3的活性为目标。我们建议资助的项目是处理调节正常和突变ABCA3的生理功能的因素。我们计划研究决定板层体膜中ABCA3含量的机制。其中包括蛋白质的贩运和翻译后调节。我们研究的另一个焦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一种新的磷脂酰胆碱衍生物的使用来分析，这种新的磷脂酰胆碱衍生物与自然产生的底物比迄今使用的大多数化合物更相似。为了能够精确地分析突变效应，我们使用锌指核酸酶技术产生了ABCA3基因敲除细胞系。除了体外研究，我们计划分析ABCA3突变患者肺组织中ABCA3的数量和定位，从而在体外数据和临床表型之间建立联系。体外研究结果与来自ABCA3突变患者肺组织的体外数据的相关性将促进旨在增加ABCA3肺功能活性的治疗干预的新方法。从我们建议的资助项目中，我们期待对ABCA3的功能和调节、ABCA3突变造成的它们的干扰以及纠正它们的新的实验方法有新的见解。这些发现将为ABCA3功能的调节提供新的治疗方法。此外，对ABCA3细胞生物学的更好理解也将使我们能够得出关于ABCA家族其他成员的结论，这些成员的细胞生物学基本上是未知的。

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.