Faculty Collaboration Database

Persistent pulmonary hypertension alters the epigenetic characteristics of endothelial nitric oxide synthase gene in pulmonary artery endothelial cells in a fetal lamb model. Physiol Genomics 2018 Oct 01;50(10):828-836

Date

07/14/2018

Pubmed ID

30004838

Pubmed Central ID

PMC6230868

DOI

10.1152/physiolgenomics.00047.2018

Scopus ID

2-s2.0-85055279790 (requires institutional sign-in at Scopus site)   24 Citations

Abstract

Decreased expression of endothelial nitric oxide synthase (eNOS), a key mediator of perinatal transition, characterizes persistent pulmonary hypertension of the newborn (PPHN) in neonates and a fetal lamb model; the mechanisms are unclear. We investigated whether increased DNA CpG methylation at the eNOS promoter in estrogen response elements (EREs) and altered histone code together contribute to decreased eNOS expression in PPHN. We isolated pulmonary artery endothelial cells (PAEC) from fetal lambs with PPHN induced by prenatal ductus arteriosus constriction from 128 to 136 days gestation or gestation-matched twin controls. We measured right ventricular systolic pressure (RVSP) and Fulton index and determined eNOS expression in PAEC in control and PPHN lambs. We determined DNA CpG methylation by pyrosequencing and activity of ten eleven translocase demethylases (TET) by colorimetric assay. We quantified the occupancy of transcription factors, specificity protein 1 (Sp1), and estrogen receptors and density of four histone marks around Sp1 binding sites by chromatin immunoprecipitation (ChIP) assays. Fetal lambs with PPHN developed increased RVSP and Fulton index. Levels of eNOS mRNA and protein were decreased in PAEC from PPHN lambs. PPHN significantly increased the DNA CpG methylation in eNOS promoter and decreased TET activity in PAEC. PPHN decreased Sp1 occupancy and density of the active mark, lysine 12 acetylation of histone 4, and increased density of the repression mark, lysine 9 trimethylation of histone 3 around Sp1 binding sites in eNOS promoter. These results suggest that epigenetic modifications are primed to decrease Sp1 binding at the eNOS gene promoter in PPHN.

Author List

Ke X, Johnson H, Jing X, Michalkiewicz T, Huang YW, Lane RH, Konduri GG

Authors

Xi-Gang Jing Research Scientist I in the Pediatrics department at Medical College of Wisconsin
Hollis M. Johnson Instructor II in the Pediatrics department at Medical College of Wisconsin
Girija Ganesh Konduri MD Chief, Professor in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Animals, Newborn
Cells, Cultured
DNA Methylation
Disease Models, Animal
Endothelial Cells
Epigenesis, Genetic
Female
Gene Expression Regulation, Developmental
Histone Code
Hypertension, Pulmonary
Nitric Oxide Synthase Type III
Pregnancy
Promoter Regions, Genetic
Pulmonary Artery
Sheep