ABCMdb

PMID: 14761197

Marivingt-Mounir C, Norez C, Derand R, Bulteau-Pignoux L, Nguyen-Huy D, Viossat B, Morgant G, Becq F, Vierfond JM, Mettey Y
Synthesis, SAR, crystal structure, and biological evaluation of benzoquinoliziniums as activators of wild-type and mutant cystic fibrosis transmembrane conductance regulator channels.
J Med Chem. 2004 Feb 12;47(4):962-72., 2004-02-12 [PubMed]

Sentences

No. Mutations Sentence Comment

5 ABCC7 p.Gly551Asp Synthesized compounds were evaluated on wild-type CFTR and on CFTR having the glycine-to-aspartic acid missense mutation at codon 551 (G551D-CFTR), using a robot and cell-based assay. Login to comment 11 ABCC7 p.Gly551Asp The class III mutation glycine-to-aspartic acid at codon 551 (G551D) is found with a frequency of 2-5% in chromosomal analysis, depending on the population of origin. Login to comment 12 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp G551D is indeed one of the five most frequent CF mutations being always associated with a severe CF phenotype, pulmonary dysfunction, and pancreatic insufficiency.7 The G551D mutation is located within the first nucleotide binding domain of CFTR.7 Despite the fact that G551D mutated protein is fully glycosylated6,8 and normally phosphorylated at the R domain by cAMP-dependent protein kinases,9 its chloride channel activity cannot be stimulated pharmacologically by cAMP-elevating agents.6,7,10 G551D mutation also confers a decreased nucleotide binding11 and a reduced ATPase activity at NBD1.12,13 Searching for potent and specific small molecules able to modulate normal and mutated CFTR is crucial for both our understanding of the physiological role of CFTR in epithelial cell function and for the development of molecules of therapeutic interest to cure CF. In this regard, the pharmacology of G551D-CFTR chloride channel activity has not been clearly and systematically characterized and compared to that of wild-type CFTR channel. Login to comment 13 ABCC7 p.Gly551Asp Recently, we have demonstrated that the benzo[c]quinolizinium derivatives MPB-07 (8a), MPB-27 (8d), and MPB-91 (8t) are activators of wild-type (wt) CFTR.14,15 Among these, only MPB-9115 but not MPB- 0715,16 was found capable to activate G551D-CFTR chloride channels. Login to comment 21 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp || Laboratoire de Cristallographie et RMN Biologiques, Universite´ de Paris V. 962 J. Med. Chem. 2004, 47, 962-972 10.1021/jm0308848 CCC: $27.50 (c) 2004 American Chemical Society Published on Web 01/17/2004 salts and generated many derivatives that have been tested on both wtand G551D-CFTR chloride channel activity. Login to comment 39 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp Functional Analysis of the Effect of Benzo[c]- quinolizinium and Benzo[f]indolo[2,3-a]quinolizinium Salts on the Chloride Channel Activities of Wtand G551D-CFTR. Login to comment 41 ABCC7 p.Gly551Asp Chinese hamster ovary (CHO) cell lines stably expressing wt-CFTR14 and G551D-CFTR15 were used. Login to comment 67 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp The pharmacological characteristics of CFTR chloride channel having the glycine-to-aspartate mutation at codon 551 (G551D) were then studied. Login to comment 69 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp G551D-CFTR channels expressed in CHO cells are not responsive to up to 10 µM Fsk, as previously reported.15,21 This lack of responsiveness of G551D-CFTR to cAMP agonists constitutes a hallmark of the mutant and a major difference with wild-type CFTR. Login to comment 70 ABCC7 p.Gly551Asp To determine the effect of compounds 8 on G551D-CFTR activity, cells were first exposed to 10 µM Fsk and then to these derivatives. Login to comment 71 ABCC7 p.Gly551Asp In G551D-CFTR cells, in the absence of Fsk, the peak rate of 125I efflux was 0.09 ( 0.01 min-1 (n ) 14) and did not significantly differ from experiments in which 10 µM Fsk was added (0.10 ( 0.01 min-1, n ) 14, Figure 2B). Login to comment 72 ABCC7 p.Gly551Asp We then studied the effect of compounds 8 on G551D-CFTR activity in the presence of 10 µM Fsk. Login to comment 74 ABCC7 p.Gly551Asp The stimulation of G551D-CFTR activity by 8u increased dose-dependently with an EC50 ) 0.75 ( 0.15 µM (Figure 2B and Table 4). Login to comment 77 ABCC7 p.Gly551Asp For each compound, the respective EC50 was determined for both wt-CFTR and G551D-CFTR channels. Login to comment 78 ABCC7 p.Gly551Asp As can be seen from Table 4, compounds 8a and 8d were considered inactive on G551D-CFTR, because we could not determine the EC50, which must be above 200 µM. Login to comment 79 ABCC7 p.Gly551Asp In contrast, the remaining six compounds 8u, 8v, 8t, 8w, 8s, and 8j were potent activators of both wt-CFTR and G551D-CFTR. Login to comment 97 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp Half-Maximal Effective Concentration (EC50) Determined for the Eight Most Potent Benzo[c]quinolizinium Derivativesa EC50 (µM) compound wt G551D 8u MPB-104 1.70 ( 0.15 0.75 ( 0.15 8v MPB-97 21.0 ( 1.5 20.0 ( 1.5 8t MPB-91 23.5 ( 1.5 34.0 ( 2 8w MPB-95 26.0 ( 1.5 32.5 ( 1.5 8s MPB-96 54.2 ( 1.2 48.0 ( 1.3 8j MPB-77 70.5 ( 1.5 95.0 ( 1.5 8a MPB-07 141 ( 15 >200 8d MPB-27 146 ( 14 >200 a Data are given as mean ( SEM for n ) 6 for each drug tested for wt-CFTR and G551D-CFTR. Login to comment 98 ABCC7 p.Gly551Asp For the effect of 8a and 8d on G551D-CFTR, the dose-response relationship was not completed and the EC50 was estimated to be above 200 µM, a concentration too high compared to the other congeners. Login to comment 99 ABCC7 p.Gly551Asp Experiments were performed in the presence of 1 µM Fsk (wt-CFTR) or 10 µM Fsk (G551D-CFTR). Login to comment 100 ABCC7 p.Gly551Asp trafficking-competent G551D mutant after forskolin exposure.21,35 In our first report concerning the activity of benzo[c]- quinoliziniums on wt-CFTR chloride channel expressed in CHO cells,14 we studied only four compounds. Login to comment 111 ABCC7 p.Gly551Asp Effect of MPB-104 (8u) on wt-CFTR (A) and G551D-CFTR (B) activity. Login to comment 113 ABCC7 p.Gly551Asp On the right are presented the dose-response relationships for MPB-104 in the presence of 1 µM Fsk (wt-CFTR, A) or 10 µM Fsk (G551D-CFTR, B). Login to comment 115 ABCC7 p.Gly551Asp The half-maximal effective concentration EC50 was 1.70 ( 0.15 µM and 0.75 ( 0.15 µM for wt-CFTR and G551D-CFTR, respectively. Login to comment 132 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp MPB-104, being the most potent drug of the series, has the same efficacy on both wtand G551D-CFTR. Login to comment 136 ABCC7 p.Gly551Asp These compounds were tested on wild-type CFTR and on G551D-CFTR, a class III CF mutation, using a robot and cell-based assay. Login to comment 240 ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp ABCC7 p.Gly551Asp Chinese hamster ovary (CHO) cells stably transfected with pNUT vector alone (pNUT CHO) or containing wild-type CFTR (CFTR(+) CHO) or G551D (G551D CHO) mutation were provided by J. R. Riordan and X.-B. Chang, Scottsdale, AZ.2,9 Cells cultured at 37 °C in 5% CO2 were maintained in MEM containing 7% fetal bovine serum, 0.5% antibiotics (50 IU/mL penicillin and 50 µg/mL streptomycin) and 100 or 20 µM methotrexate for CFTR(+) and G551D or pNUT CHO cells, respectively. Login to comment