title: cAMP induces hypertrophy and alters DNA methylation in HL-1 cardiomyocytes.
abstract: cAMP is a highly regulated secondary messenger involved in many biological processes. Chronic activation of the cAMP pathway by catecholamines results in cardiac hypertrophy and fibrosis; however, the mechanism by which elevated cAMP leads to cardiomyopathy is not fully understood. To address this issue, we increased intracellular cAMP levels in HL-1 cardiomyocytes, a cell line derived from adult mouse atrium, using either the stable cAMP analog N(6),2'-O-dibutyryladenosine 3',5'-cyclic monophosphate (DBcAMP) or phosphodiesterase (PDE) inhibitors caffeine and theophylline. Elevated cAMP levels increased cell size and altered expression levels of cardiac genes and micro-RNAs associated with hypertrophic cardiomyopathy (HCM), including Myh6, Myh7, Myh7b, Tnni3, Anp, Bnp, Gata4, Mef2c, Mef2d, Nfatc1, miR208a, and miR208b. In addition, DBcAMP altered the expression of DNA methyltransferases (Dnmts) and Tet methylcytosine dioxygenases (Tets), enzymes that regulate genomic DNA methylation levels. Changes in expression of DNA methylation genes induced by elevated cAMP led to increased global DNA methylation in HL-1 cells. In contrast, inhibition of DNMT activity with 5-azacytidine treatment decreased global DNA methylation levels and blocked the increased expression of several HCM genes (Myh7, Gata4, Mef2c, Nfatc1, Myh7b, Tnni3, and Bnp) observed with DBcAMP treatment. These results demonstrate that cAMP induces cardiomyocyte hypertrophy and altered HCM gene expression in vitro and that DNA methylation patterns mediate the upregulation of HCM genes induced by cAMP. These data identify a previously unknown mechanism by which elevated levels of cAMP lead to increased expression of genes associated with cardiomyocyte hypertrophy.
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida xiefanfang@ufl.edu.
authors.forename: Xiefan
authors.initials: X
authors.lastname: Fang
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida.
authors.forename: Jourdon
authors.initials: J
authors.lastname: Robinson
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida.
authors.forename: John
authors.initials: J
authors.lastname: Wang-Hu
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida.
authors.forename: Lingli
authors.initials: L
authors.lastname: Jiang
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Freeman
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Rivkees
authors.affiliation: Department of Pediatrics, Child Health Research Institute, College of Medicine, University of Florida, Gainesville, Florida.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Wendler
mesh_terms: D000818:Animals; D006332:Cardiomegaly / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D009202:Cardiomyopathies / Q000235:genetics* / Q000473:pathology; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D019175:DNA Methylation / Q000235:genetics* / Q000502:physiology; D015870:Gene Expression / Q000235:genetics; D006321:Heart / Q000503:physiopathology; D051379:Mice; D035683:MicroRNAs / Q000235:genetics; D032383:Myocytes, Cardiac / Q000378:metabolism* / Q000473:pathology*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D035683:MicroRNAs; D000242:Cyclic AMP
keywords: adenosine 3′,5′-cyclic monophosphate; cardiomyocyte hypertrophy; deoxyribonucleic acid methylation