genistein and Cystic-Fibrosis

Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) ion channel are established as the primary causative factor in the devastating lung disease cystic fibrosis (CF). More recently, cigarette smoke exposure has been shown to be associated with dysfunctional airway epithelial ion transport, suggesting a role for CFTR in the pathogenesis of chronic obstructive pulmonary disease (COPD). Here, the identification and characterization of a high throughput screening hit

Topics: Administration, Oral; Aminopyridines; Animals; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Disease Models, Animal; Drug Evaluation, Preclinical; Gene Deletion; Half-Life; Humans; Protein Binding; Pulmonary Disease, Chronic Obstructive; Rats; Rats, Sprague-Dawley; Solubility; Structure-Activity Relationship

The pharmacology of the cystic fibrosis transmembrane conductance regulator (CFTR) Cl(-) channel has attracted significant interest in recent years with the aim to search for rational new therapies for diseases caused by CFTR malfunction. Mutations that abolish the function of CFTR cause the life-threatening genetic disease cystic fibrosis (CF). The most common cause of CF is the deletion of phenylalanine 508 (ΔF508) in the CFTR chloride channel. Felodipine, nifedipine, and other antihypertensive 1,4-dihydropyridines (1,4-DHPs) that block L-type Ca(2+) channels are also effective potentiators of CFTR gating, able to correct the defective activity of ΔF508 and other CFTR mutants ( Mol. Pharmacol. 2005 , 68 , 1736 ). For this purpose, we evaluated the ability of the previously and newly synthesized 4-imidazo[2,1-b]thiazoles-1,4-dihydropyridines without vascular activity and inotropic and/or chronotropic cardiac effects ( J. Med. Chem. 2008 , 51 , 1592 ) to enhance the activity of ΔF508-CFTR. Our studies indicate compounds 17, 18, 20, 21, 38, and 39 as 1,4-DHPs with an interesting profile of activity.

Topics: Amino Acid Sequence; Animals; Antihypertensive Agents; Bacterial Proteins; Cell Line; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Epithelial Cells; Guinea Pigs; Heart Rate; Ion Channel Gating; Luminescent Proteins; Molecular Targeted Therapy; Mutation; Myocardial Contraction; Myocytes, Smooth Muscle; Nifedipine; Sequence Deletion

Chemical modulation of histone deacetylase (HDAC) activity by HDAC inhibitors (HDACi) is an increasingly important approach for modifying the etiology of human disease. Loss-of-function diseases arise as a consequence of protein misfolding and degradation, which lead to system failures. The DeltaF508 mutation in cystic fibrosis transmembrane conductance regulator (CFTR) results in the absence of the cell surface chloride channel and a loss of airway hydration, leading to the premature lung failure and reduced lifespan responsible for cystic fibrosis. We now show that the HDACi suberoylanilide hydroxamic acid (SAHA) restores surface channel activity in human primary airway epithelia to levels that are 28% of those of wild-type CFTR. Biological silencing of all known class I and II HDACs reveals that HDAC7 plays a central role in restoration of DeltaF508 function. We suggest that the tunable capacity of HDACs can be manipulated by chemical biology to counter the onset of cystic fibrosis and other human misfolding disorders.

Topics: Animals; Bronchi; Cell Membrane; Cricetinae; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Epithelial Cells; Gene Silencing; Histone Deacetylases; Humans; Hydroxamic Acids; Mutation; Protein Denaturation; Protein Folding; RNA, Small Interfering; Vorinostat

The gating of the CFTR chloride channel is altered by a group of mutations that cause cystic fibrosis. This gating defect may be corrected by small molecules called potentiators. Some 1,4-dihydropyridine (DHP) derivatives, bearing a thiophen-2-yl and a furanyl ring at the 4-position of the nucleus, were prepared and tested as CFTR potentiators. In particular, we evaluated the ability of novel DHPs to enhance the activity of the rescued DeltaF508-CFTR as measured with a functional assay based on the halide-sensitive yellow fluorescent protein. Most DHPs showed an effect comparable to or better than that of the reference compound genistein. The potency was instead significantly improved, with some compounds, such as 3g, 3h, 3n, 4a, 4b, and 4d, having a half effective concentration in the submicromolar range. CoMFA analysis gave helpful suggestions to improve the activity of DHPs.

Topics: Animals; Cell Line; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Dihydropyridines; Humans; Ion Channel Gating; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microscopy, Fluorescence; Quantitative Structure-Activity Relationship; Rats; Thiophenes

The mechanism of action of a novel CFTR activator UC(CF)-029 on NIH3T3 cells stably expressing DeltaF508-CFTR was investigated and its effects compared to those of genistein, a known CFTR activator. This study shows that UC(CF)-029 and genistein have differing efficacies. The efficacy of UC(CF)-029 in the presence of forskolin (10microM) is approximately 50% that of genistein; however, the EC(50)'s for both drugs are comparable; 3.5microM for UC(CF)-029 and 4.4muM for genistein. Using NIH3T3 cells stably transfected with K1250A-CFTR we find that CFTR channel open time is unaffected by UC(CF)-029 or genistein, supporting the hypothesis that these compounds stabilize the open state by inhibiting ATP hydrolysis at NBD2. Our data suggest that the ability of UC(CF)-029 to augment DeltaF508-CFTR channel activity necessitates further interest.

Topics: Adenosine Triphosphate; Animals; Benzoflavones; Colforsin; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Dose-Response Relationship, Drug; Drug Design; Genistein; Hydrolysis; Mice; Models, Chemical; NIH 3T3 Cells; Protein Kinase Inhibitors; Transfection