Epigenetic regulation of the endothelial nitric oxide synthase gene in persistent pulmonary hypertension of the newborn rat.
OBJECTIVE
Persistent pulmonary hypertension of the newborn (PPHN) is a major clinical problem. Nitric oxide produced by endothelial nitric oxide synthase (eNOS) in endothelial cells plays an important role in the pathogenesis of PPHN. The eNOS expression in endothelial cells is controlled by epigenetic regulation. The aim of this study was to investigate the epigenetic regulatory mechanisms of the eNOS gene in PPHN.


METHODS
The rat model of PPHN was induced by hypoxia and indomethacin. Pulmonary vascular endothelial cells were isolated from the fetal rat lungs by magnetic-activated cell sorting. Chromatin immunoprecipitation and bisulfite sequencing methods were used to analyze epigenetic regulation.


RESULTS
The levels of acetylated histone H3 and acetylated histone H4 at the proximal promoter of the eNOS gene in pulmonary vascular endothelial cells from PPHN were significantly higher than those from the control group (P < 0.01, respectively). Total methylation percentage of the eNOS gene promoter in PPHN rat was slightly lower than that of control, but there was no statistically significant difference between the two groups (24.7 ± 2.0 vs. 27.3 ± 2.3%, P = 0.408). These changes of epigenetic modifications at the eNOS gene promoter were consistent with increased levels of eNOS mRNA and protein in PPHN.


CONCLUSIONS
The increased expression of eNOS in PPHN was associated with epigenetic regulation.
Xu
Xue-Feng
XF
The Children's Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.
Ma
Xiao-Lu
XL
Shen
Zheng
Z
Wu
Xi-Ling
XL
Cheng
Fen
F
Du
Li-Zhong
LZ
D000818:Animals; D000831:Animals, Newborn; D018899:CpG Islands; D019175:DNA Methylation; D004195:Disease Models, Animal; D042783:Endothelial Cells / Q000166:cytology; D044127:Epigenesis, Genetic; D005260:Female; D006976:Hypertension, Pulmonary / Q000235:genetics*; D020097:Natriuretic Peptide, Brain / Q000097:blood; D052250:Nitric Oxide Synthase Type III / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D020097:Natriuretic Peptide, Brain; D052250:Nitric Oxide Synthase Type III