title: Proarrhythmic effect of sustained EPAC activation on TRPC3/4 in rat ventricular cardiomyocytes.
abstract: The Exchange Protein directly Activated by cAMP (EPAC) participates to the pathological signaling of cardiac hypertrophy and heart failure, in which the role of Ca(2+) entry through the Transient Receptor Potential Canonical (TRPC) channels begin to be appreciated. Here we studied whether EPAC activation could influence the activity and/or expression of TRPC channels in cardiac myocytes. In adult rat ventricular myocytes treated for 4 to 6h with the selective EPAC activator, 8-pCPT (10μM), we observed by Fluo-3 confocal fluorescence a Store-Operated Ca(2+) Entry (SOCE) like-activity, which was blunted by co-incubation with EPAC inhibitors (ESI-05 and CE3F4 at 10 μM). This SOCE-like activity, which was very small in control incubated cells, was sensitive to 30-μM SKF-96365. Molecular screening showed a specific upregulation of TRPC3 and C4 protein isoforms after 8-pCPT treatment. Moreover, sustained EPAC activation favored proarrhythmic Ca(2+) waves, which were reduced either by co-incubation with EPAC inhibitors or bath perfusion with TRPC inhibitors. Our study provides the first evidence that sustained selective EPAC activation leads to an increase in TRPC3 and C4 protein expression and induces a proarrhythmic SOCE-like activity in adult rat ventricular cardiomyocytes, which might be of importance during the development of cardiac diseases.
authors.affiliation: Inserm, UMR-S 1180, Châtenay-Malabry, France; Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France; Institute of Biomedicine of Seville, Seville, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Domínguez-Rodríguez
authors.affiliation: Inserm, UMR-S 1180, Châtenay-Malabry, France; Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France.
authors.forename: Gema
authors.initials: G
authors.lastname: Ruiz-Hurtado
authors.affiliation: Inserm, UMR-S 1180, Châtenay-Malabry, France; Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France.
authors.forename: Jessica
authors.initials: J
authors.lastname: Sabourin
authors.affiliation: Inserm, UMR-S 1180, Châtenay-Malabry, France; Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France.
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Gómez
authors.affiliation: Inserm, UMR-S 1180, Châtenay-Malabry, France; Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France; Laboratorio de Electrofisiología. Instituto de Cardiología y Cirugía Cardiovascular, La Habana, Cuba.
authors.forename: Julio L
authors.initials: JL
authors.lastname: Alvarez
authors.affiliation: Inserm, UMR-S 1180, Châtenay-Malabry, France; Faculté de Pharmacie, Université Paris Sud, Labex LERMIT, DHU TORINO, Châtenay-Malabry, France. Electronic address: jean-pierre.benitah@inserm.fr.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Benitah
mesh_terms: D000818:Animals; D001555:Benzene Derivatives / Q000008:administration & dosage; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects; D006332:Cardiomegaly / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology; D003181:Complement C4 / Q000096:biosynthesis* / Q000235:genetics; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000008:administration & dosage / Q000031:analogs & derivatives; D020662:Guanine Nucleotide Exchange Factors / Q000096:biosynthesis* / Q000235:genetics; D006352:Heart Ventricles / Q000378:metabolism / Q000473:pathology; D006801:Humans; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D011804:Quinolines / Q000008:administration & dosage; D051381:Rats; D013450:Sulfones / Q000008:administration & dosage; D050052:TRPC Cation Channels / Q000037:antagonists & inhibitors / Q000235:genetics*; D013873:Thionucleotides / Q000008:administration & dosage
chemical_list: C588037:6-fluoro-5,7-dibromo-2-methyl-1-formyl-1,2,3,4-tetrahydroquinoline; D001555:Benzene Derivatives; D003181:Complement C4; C000589230:ESI-05; D020662:Guanine Nucleotide Exchange Factors; D011804:Quinolines; C526973:Rapgef3 protein, rat; D013450:Sulfones; D050052:TRPC Cation Channels; C104603:TRPC3 cation channel; D013873:Thionucleotides; C055656:8-((4-chlorophenyl)thio)cyclic-3',5'-GMP; D000242:Cyclic AMP; D006152:Cyclic GMP; D002118:Calcium
keywords: Cardiomyocyte; Exchange Protein directly Activated by Cyclic AMP (EPAC); Store-Operated Ca(2+) Entry (SOCE); Transient Receptor Potential Canonical (TRPC) channels