Molecular basis of cystic fibrosis: from bench to bedside

Abstract

Cystic fibrosis (CF), is an autosomal recessive disease affecting different organs. The lung disease, characterized by recurrent and chronic bacterial infection and inflammation since infancy, is the main cause of morbidity and precocious mortality of these individuals. The innovative therapies directed to repair the defective CF gene should account for the presence of more than 200 disease-causing mutations of the CF transmembrane conductance regulator (CFTR) gene. The review will recall the different experimental approaches in discovering CFTR protein targeted molecules, such as the high throughput screening on chemical libraries to discover correctors and potentiators of CFTR protein, dual-acting compounds, read-through molecules, splicing defects repairing tools, CFTR "amplifiers".

Keywords: CFTR potentiators; Cystic fibrosis (CF); cystic fibrosis transmembrane conductance regulator correctors (CFTR correctors); personalized medicine.

Figure 1

The molecular defects of CFTR protein. Paradigmatic CF gene mutations are reported in association to the schematic representation of six classes of cellular and molecular defects of CFTR protein, as described in the text. CFTR, cystic fibrosis transmembrane conductance regulator; CF, cystic fibrosis.

Figure 2

Fluorescence-based assays for high-throughput screening of chemical libraries to detect functional CFTR protein. (A) Chloride-sensitive fluorescent probes (SPQ, MQAE) undergoing collisional quenching upon interaction with chloride ion or other halides (e.g., iodide). Agonists activating efflux of chloride ion from inside to outside the cell reduce the quenching of the fluorescent probe (47); (B) membrane potential-sensitive fluorescent molecules partition from extracellular space to the plasma membrane as a function of chloride efflux-dependent depolarization. Partition of the probe inside the less polar plasma membrane dramatically increases quantum yield and consequently the emission of fluorescence (48); (C) yellow fluorescent protein (YFP) made sensitive to collisional quenching to halides reduces the emission of light as a function of entry of chloride or iodide inside the cell (49). CFTR, cystic fibrosis transmembrane conductance regulator.