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Huguet F, Calvez ML, Benz N, Le Hir S, Mignen O, Buscaglia P, Horgen FD, Férec C, Kerbiriou M, Trouvé P. Function and regulation of TRPM7, as well as intracellular magnesium content, are altered in cells expressing ΔF508-CFTR and G551D-CFTR. Cell Mol Life Sci 2016; 73:3351-73. [PMID: 26874684 DOI: 10.1007/s00018-016-2149-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 01/14/2016] [Accepted: 01/25/2016] [Indexed: 02/03/2023]
Abstract
Cystic fibrosis (CF), one of the most common fatal hereditary disorders, is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR gene product is a multidomain adenosine triphosphate-binding cassette (ABC) protein that functions as a chloride (Cl(-)) channel that is regulated by intracellular magnesium [Mg(2+)]i. The most common mutations in CFTR are a deletion of a phenylalanine residue at position 508 (ΔF508-CFTR, 70-80 % of CF phenotypes) and a Gly551Asp substitution (G551D-CFTR, 4-5 % of alleles), which lead to decreased or almost abolished Cl(-) channel function, respectively. Magnesium ions have to be finely regulated within cells for optimal expression and function of CFTR. Therefore, the melastatin-like transient receptor potential cation channel, subfamily M, member 7 (TRPM7), which is responsible for Mg(2+) entry, was studies and [Mg(2+)]i measured in cells stably expressing wildtype CFTR, and two mutant proteins (ΔF508-CFTR and G551D-CFTR). This study shows for the first time that [Mg(2+)]i is decreased in cells expressing ΔF508-CFTR and G551D-CFTR mutated proteins. It was also observed that the expression of the TRPM7 protein is increased; however, membrane localization was altered for both ΔF508del-CFTR and G551D-CFTR. Furthermore, both the function and regulation of the TRPM7 channel regarding Mg(2+) is decreased in the cells expressing the mutated CFTR. Ca(2+) influx via TRPM7 were also modified in cells expressing a mutated CFTR. Therefore, there appears to be a direct involvement of TRPM7 in CF physiopathology. Finally, we propose that the TRPM7 activator Naltriben is a new potentiator for G551D-CFTR as the function of this mutant increases upon activation of TRPM7 by Naltriben.
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Affiliation(s)
- F Huguet
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Faculté de Médecine et des sciences de la santé, Université de Bretagne Occidentale, Brest, 29200, France
| | - M L Calvez
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Faculté de Médecine et des sciences de la santé, Université de Bretagne Occidentale, Brest, 29200, France.,Association G. Saleun, Brest, 29218, France
| | - N Benz
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Association G. Saleun, Brest, 29218, France
| | - S Le Hir
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Laboratoire de Génétique Moléculaire, Hôpital Morvan, C.H.U. Brest, Brest, 29200, France
| | - O Mignen
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Faculté de Médecine et des sciences de la santé, Université de Bretagne Occidentale, Brest, 29200, France
| | - P Buscaglia
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Faculté de Médecine et des sciences de la santé, Université de Bretagne Occidentale, Brest, 29200, France
| | - F D Horgen
- Laboratory of Marine Biological Chemistry, Department of Natural Sciences, Hawaii Pacific University, Kaneohe, HI, 96744, USA
| | - C Férec
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France. .,Faculté de Médecine et des sciences de la santé, Université de Bretagne Occidentale, Brest, 29200, France. .,Laboratoire de Génétique Moléculaire, Hôpital Morvan, C.H.U. Brest, Brest, 29200, France. .,Etablissement Français du Sang - Bretagne, Brest, 29200, France.
| | - M Kerbiriou
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.,Faculté de Médecine et des sciences de la santé, Université de Bretagne Occidentale, Brest, 29200, France
| | - P Trouvé
- Inserm, UMR1078, 46, rue Félix le Dantec, CS 51819, 29218, Brest Cedex 2, France.
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