Potentiation of ΔF508- and G551D-CFTR-Mediated Cl- Current by Novel Hydroxypyrazolines

• Published in: PloS one Vol. 11; no. 2; p. e0149131
• Main Authors: Park, Jinhong, Khloya, Poonam, Seo, Yohan, Kumar, Satish, Lee, Ho K., Jeon, Dong-Kyu, Jo, Sungwoo, Sharma, Pawan K., Namkung, Wan
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 10.02.2016; Public Library of Science (PLoS)
• Subjects: Aminopyridines - therapeutic use; Animals; Bacterial Proteins - chemistry; Benzodioxoles - therapeutic use; Biology and Life Sciences; Cell Line; Cell Line, Tumor; Cell Membrane - metabolism; Cell Proliferation; Channel gating; Chemical synthesis; Chloride; Chloride conductance; Chlorides; Chlorides - chemistry; Clinical trials; Cyclic AMP - metabolism; Cystic fibrosis; Cystic Fibrosis - drug therapy; Cystic Fibrosis - genetics; Cystic Fibrosis Transmembrane Conductance Regulator - genetics; Cytotoxicity; Defects; Epithelial Cells - cytology; Gene Deletion; Genistein; Genistein - chemistry; Humans; Kinases; Luminescent Proteins - chemistry; Medicine and Health Sciences; Membrane trafficking; Mutation; Nose - physiology; Patch-Clamp Techniques; Pharmaceutical sciences; Pharmacy; Phenylalanine; Phenylalanine - genetics; Physical Sciences; Plasma; Potentiation; Proteins; Pyrazoles - therapeutic use; Rats; Research and analysis methods; Resistance; Structure-Activity Relationship; Sulfonamides - therapeutic use; Toxicity; India
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0149131

The most common mutation of CFTR, affecting approximately 90% of CF patients, is a deletion of phenylalanine at position 508 (F508del, ΔF508). Misfolding of ΔF508-CFTR impairs both its trafficking to the plasma membrane and its chloride channel activity. To identify small molecules that can restore channel activity of ΔF508-CFTR, we synthesized and evaluated eighteen novel hydroxypyrazoline analogues as CFTR potentiators. To elucidate potentiation activities of hydroxypyrazolines for ΔF508-CFTR, CFTR activity was measured using a halide-sensitive YFP assay, Ussing chamber assay and patch-clamp technique. Compounds 7p, 7q and 7r exhibited excellent potentiation with EC50 value <10 μM. Among the compounds, 7q (a novel CFTR potentiator, CP7q) showed the highest potentiation activity with EC50 values of 0.88 ± 0.11 and 4.45 ± 0.31 μM for wild-type and ΔF508-CFTR, respectively. In addition, CP7q significantly potentiated chloride conductance of G551D-CFTR, a CFTR gating mutant; its maximal potentiation activity was 1.9 fold higher than the well-known CFTR potentiator genistein. Combination treatment with CP7q and VX-809, a corrector of ΔF508-CFTR, significantly enhanced functional rescue of ΔF508-CFTR compared with VX-809 alone. CP7q did not alter the cytosolic cAMP level and showed no cytotoxicity at the concentration showing maximum efficacy. The hydroxypyrazolines may be potential development candidates for drug therapy of cystic fibrosis.