UNI-MED Science / Mutation-specific therapies in cystic fibrosis

1.CFTR and cystic fibrosis13 1.1.To set the stage: Cystic Fibrosis - etiology and significance13 1.2.The Molecular Structures of CFTR13 1.2.1.CFTR is an unusual ABC transporter and an unusual ion channel14 1.2.2.Structure of the non-phosphorylated CFTR15 1.2.3.Structure of phosphorylated CFTR in complex with ATP16 1.2.4.Conformational changes leading to channel opening16 1.2.5.The TM hinge as a hotspot for CFTR potentiation17 1.3.Features of CFTR: an epithelial anion channel with complex regulation19 1.3.1.The functional architecture of CFTR19 1.3.2.Phosphorylation-dependent regulation of CFTR: the RD19 1.3.3.Regulation of CFTR channel gating by ATP binding and hydrolysis: the NBDs20 1.3.4.Anion flow through the CFTR pore: the MSDs21 1.3.5.Structural rearrangements of CFTR domains during channel gating22 1.4.Basic defect in cystic fibrosis23 1.4.1.CF mutations cause molecular defects in the CFTR Cl- channel24 1.4.2.CF-associated mutations cause deficits of CFTR function25 1.4.3.Functional deficits of CFTR mutants lead to defects in epithelial function25 1.4.4.CFTR dysfunction causes defects in non-epithelial tissues26 1.5.Population genetics of CFTR mutations26 1.6.Molecular pathology of CFTR mutations33 1.6.1.Deletions, frame-shift mutations and stop mutations33 1.6.2.Splice mutations34 1.6.3.Missense mutations34 1.6.4.The major mutation p.Phe508del34 1.7.References35 2.Bioassays to assess CFTR function in humans43 2.1.Sweat chloride test and b-adrenergic sweat secretion43 2.2.Nasal transepithelial potential difference measurements45 2.2.1.Background45 2.2.2.Principle of the assay45 2.2.3.Applications46 2.3.Intestinal current measurements47 2.3.1.Principle of the assay47 2.3.2.Applications48 2.4.Primary cystic fibrosis intestinal organoids51 2.4.1.What are organoids?51 2.4.2.Organoid swelling as measure of transepithelial ion transport51 2.4.3.Exploring organoids as living biomarker54 2.5.Immunochemical CFTR protein analysis in patients' tissues55 2.6.References56