title: Aberrant DNA Methylation of Phosphodiesterase [corrected] 4D Alters Airway Smooth Muscle Cell Phenotypes.
abstract: Airway hyperresponsiveness (AHR) is a hallmark feature in asthma characterized by exaggerated airway contractile response to stimuli due to increased airway sensitivity and chronic airway remodeling. We have previously shown that allergen-induced AHR in mice is associated with aberrant DNA methylation in the lung genome, suggesting that AHR could be epigenetically regulated, and these changes might predispose the animals to asthma. Previous studies demonstrated that overexpression of phosphodiesterase 4D (PDE4D) is associated with increased AHR. However, epigenetic regulation of this gene in asthmatic airway smooth muscle cells (ASMCs) has not been examined. In this study, we aimed to examine the relationship between epigenetic regulation of PDE4D and ASMC phenotypes. We identified CpG site-specific hypomethylation at PDE4D promoter in human asthmatic ASMCs. We next used methylated oligonucleotides to introduce CpG site-specific methylation at PDE4D promoter and examined its effect on ASMCs. We showed that PDE4D methylation decreased cell proliferation and migration of asthmatic ASMCs. We further elucidated that methylated PDE4D decreased PDE4D expression in asthmatic ASMCs, increased cAMP level, and inhibited the aberrant increase in Ca(2+) level. Moreover, PDE4D methylation reduced the phosphorylation level of downstream effectors of Ca(2+) signaling, including myosin light chain kinase and p38. Taken together, our findings demonstrate that gene-specific epigenetic changes may predispose ASMCs to asthma through alterations in cell phenotypes. Modulation of ASMC phenotypes by methylated PDE4D oligonucleotides can reverse the aberrant ASMC functions to normal phenotypes. This has provided new insight to the development of novel therapeutic options for this debilitative disease.
authors.affiliation: 1 Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland; and.
authors.forename: Amanda H Y
authors.initials: AH
authors.lastname: Lin
authors.affiliation: 2 Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Yan
authors.initials: Y
authors.lastname: Shang
authors.affiliation: 2 Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Wayne
authors.initials: W
authors.lastname: Mitzner
authors.affiliation: 1 Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland; and.|2 Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: James S K
authors.initials: JS
authors.lastname: Sham
authors.affiliation: 2 Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
authors.forename: Wan-yee
authors.initials: WY
authors.lastname: Tang
mesh_terms: D056151:Airway Remodeling; D001249:Asthma / Q000201:enzymology* / Q000235:genetics* / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D016022:Case-Control Studies; D002465:Cell Movement; D049109:Cell Proliferation; D002478:Cells, Cultured; D018899:CpG Islands; D000242:Cyclic AMP / Q000378:metabolism; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4 / Q000235:genetics*; D019175:DNA Methylation; D044127:Epigenesis, Genetic; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D032389:Myocytes, Smooth Muscle / Q000201:enzymology* / Q000473:pathology; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism; D010641:Phenotype; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012137:Respiratory System / Q000201:enzymology* / Q000473:pathology; D015398:Signal Transduction; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000242:Cyclic AMP; D009219:Myosin-Light-Chain Kinase; D048051:p38 Mitogen-Activated Protein Kinases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517376:PDE4D protein, human; D002118:Calcium
keywords: DNA methylation; airway hyperresponsiveness; airway smooth muscle cell; methylated DNA oligonucleotides; phosphodiesterase 4D