CFTR Chloride Channel Activator Screening And Molecular Pharmacology Researching

The CAMP-activated cystic fibrosis transmembrane conductance regulator (CFTR) belongs to a family of proteins called traffic ATPases or ABC transporters. Its mutation will cause the most prevalence lethal hereditary disease-cystic fibrosis (CF). It is most prominently expressed in the apical membrane of various epithelia in mammal involved secretion and absorption (such as intestine, airways, pancreas, sweat ducts), which works as Cl- channel and also a regulator of other anion channels. Therefore, CFTR is closely related to many physiological and pathological conditions. Impaired function of CFTR Cl- channels in CF disrupts transepithelial ion transport, thus leads to the wide-ranging manifestations of the disease such as idiopathic chronic pancreatitis (ICP), keratoconjunctivitis sicca (KCS), habitual constipation. Evidence also showed that over active of CFTR is associated with such diseases as secretory diarrhea and polycystic kidney disease. Identification of small-molecule modulators to regulate the function of wild-type and mutant CFTR have been attracted many attention in recent years and have obtained substantial progress, which is still one of most important fields of CFTR study.A stably transfected Fischer thyroid epithelial (FRT) cell lines co-expressing ?F508-CFTR or wt-CFTR and a green fluorescent protein mutant with ultra-high halide sensitivity (EYFP-H148Q) was generated as assay for the drug screening. Using this cell model, 8 alkaloid compounds and 6 volatile compounds were screened for CFTR-mediated halide transport. Previously, we have a systematic study to Holland and Dictamnine which have significantly activition, so we make further research and analysis on the remaining six compounds of alkaloid compounds, at the same time we also analyzedButyl-phydroxybenzoate (Bpb) which has strongest activity in the volatile oil compounds. As a result, the six alkaloid compounds and Bpb can attivate wild-type CFTR chloride channel gating. Papaverine hydrochloride, Nimodipine, Bpb and Piperine can stimulated ?F508-CFTR mediate anion transport, but had no effect on ?F508-CFTR misprocessing defect or G551D-CFTR channel gating defect. Pharmacological properties of the seven compounds were characterized systematically in terms of the dose-dependent, reversibility, activition time-course and so on. The study provided clues that they activate CFTR chloride channel through a direct binding mechanism.This studies indicated that we regard the seven compounds not only as important tools in better understanding the structure and function of CFTR but aslo as a lead compound to develop pharmacological therapy of CFTR-related disease. On the other hand, it lays a foundation for them at further exploring other aspects pharmacology mechanism.