TY - JOUR
T1 - Aberrant DNA methylation of phosphodiestarase 4D alters airway smooth muscle cell phenotypes
AU - Lin, Amanda H.Y.
AU - Shang, Yan
AU - Mitzner, Wayne
AU - Sham, James S.K.
AU - Tang, Wan Yee
N1 - Funding Information:
This work was supported by National Institute of Environmental Health Sciences grant ES016887 (W.-y.T.) and National Heart, Lung, and Blood Institute grant HL10342 (W.M.); A.H.Y.L. was supported by a postdoctoral fellowship from the American Lung Association, and Y.S. was supported by National Natural Science Foundation of China grant 81000006.
Publisher Copyright:
Copyright © 2016 by the American Thoracic Society.
PY - 2016/2
Y1 - 2016/2
N2 - 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 Ca2+ level. Moreover, PDE4D methylation reduced the phosphorylation level of downstream effectors of Ca 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.
AB - 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 Ca2+ level. Moreover, PDE4D methylation reduced the phosphorylation level of downstream effectors of Ca 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.
KW - Airway hyperresponsiveness
KW - Airway smooth muscle cell
KW - DNA methylation
KW - Methylated DNA oligonucleotides
KW - Phosphodiesterase 4D
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U2 - 10.1165/rcmb.2015-0079OC
DO - 10.1165/rcmb.2015-0079OC
M3 - Article
C2 - 26181301
AN - SCOPUS:84963818071
SN - 1044-1549
VL - 54
SP - 241
EP - 249
JO - American journal of respiratory cell and molecular biology
JF - American journal of respiratory cell and molecular biology
IS - 2
ER -