Register for Children´s interstitial lung diseases (chILD)
Identification of novel candidate genes in children with rare idiopathic lung diseases by whole exome trio analysis
Characterization of the ATP-binding cassette (ABC) transporter ABCA3 and ABCA3 mutations as a cause for interstitial lung diseases in children (chILD)
Identification of therapeutic modulators for mutant ABCA3
Prof. Dr. med. Matthias Griese
✉ Matthias.griese@med.uni-muenchen.de
☎ +49-89-4400-57870
Interstitial lung diseases are rare entities but account for a broad range of pulmonary diseases in children. The final diagnosis is often difficult and frequently a lung biopsy is needed. The European management platform is a resource which supports care and research for rare lung diseases in children. Beyond peer-review by experts, the platform functions as a register with a biobank, and follows patients over time.
In addition to the histological phenotype, subcategories of interstitial lung diseases may be defined genetically. Cases with a strong genetic indication are analyzed using Whole Exome Trio Analysis (parallel analysis and interpretation with the genetic information of healthy parents). Aim of the study is the identification of the disease-causing variant to define novel candidate genes causing the specific phenotype. Reduction of invasive diagnostic procedure in the future is desirable.
The ATP-binding cassette (ABC) transporter ABCA3 is a phospholipid transporter, which is implicated in pulmonary surfactant homeostasis and localized at the limiting membrane of lamellar bodies, the storage compartment for surfactant in alveolar type II cells. Pulmonary surfactant, a complex mixture of lipids and proteins that lines the alveolar surface, prevents alveolar collapse by reducing the surface tension at the air-liquid interface in the alveoli. Mutations in ABCA3 were identified as the most common monogenetic cause of surfactant dysfunction disorders in newborns and interstitial lung diseases in children and young adults.
Although the effect of mutations resulting in truncated or incomplete proteins can be predicted, the consequences of missense variants cannot be as easily. Therefore, we investigate the intracellular handling and disturbance of the cellular surfactant system of clinically relevant ABCA3 missense mutations..
Missense mutations in ABCA3 might either impair correct folding of the protein or its function. Misfolding of the protein leads to its degradation and impedes its normal processing and trafficking to the outer membrane of lamellar bodies. Mutations in the nucleotide binding domains in contrast can lead to functional impairment of the protein by abolishing ATP binding or hydrolysis. Recent advances in the identification of modulators of CFTR, an ABC transporter that is mutated in cystic fibrosis patients, revealed the possibilities of pharmacological rescue of mutant proteins by so called correctors and potentiators, that either rescue the folding and processing of the mutant protein or its function, respectively. We identified several correctors and potentiators for mutant ABCA3 and established a high-throughput screen to identify further modulators in cooperation with the Assay Development and Screening Platform (ADSP) of the Helmholtz Center Munich.
