Antenatal hypoxia induces epigenetic repression of glucocorticoid receptor and promotes ischemic-sensitive phenotype in the developing heart
Document Type
Article
Publication Date
2-1-2016
Publication Title
Journal of molecular and cellular cardiology
E-ISSN
1095-8584
Abstract
Large studies in humans and animals have demonstrated a clear association of an adverse intrauterine environment with an increased risk of cardiovascular disease later in life. Yet mechanisms remain largely elusive. The present study tested the hypothesis that gestational hypoxia leads to promoter hypermethylation and epigenetic repression of the glucocorticoid receptor (GR) gene in the developing heart, resulting in increased heart susceptibility to ischemia and reperfusion injury in offspring. Hypoxic treatment of pregnant rats from day 15 to 21 of gestation resulted in a significant decrease of GR exon 14, 15, 16, and 17 transcripts, leading to down-regulation of GR mRNA and protein in the fetal heart. Functional cAMP-response elements (CREs) at -4408 and -3896 and Sp1 binding sites at -3425 and -3034 were identified at GR untranslated exon 1 promoters. Hypoxia significantly increased CpG methylation at the CREs and Sp1 binding sites and decreased transcription factor binding to GR exon 1 promoter, accounting for the repression of the GR gene in the developing heart. Of importance, treatment of newborn pups with 5-aza-2'-deoxycytidine reversed hypoxia-induced promoter methylation, restored GR expression and prevented hypoxia-mediated increase in ischemia and reperfusion injury of the heart in offspring. The findings demonstrate a novel mechanism of epigenetic repression of the GR gene in fetal stress-mediated programming of ischemic-sensitive phenotype in the heart.
Volume
91
First Page
160
Last Page
71
DOI
10.1016/j.yjmcc.2016.01.003
PubMed ID
26779948
Recommended Citation
Xiong, Fuxia; Lin, Thant; Song, Minwoo; Ma, Qingyi; Martinez, Shannalee R.; Lv, Juanxiu; MataGreenwood, Eugenia; Xiao, Daliao; Xu, Zhice; and Zhang, Lubo, "Antenatal hypoxia induces epigenetic repression of glucocorticoid receptor and promotes ischemic-sensitive phenotype in the developing heart" (2016). Loma Linda University Faculty Publications. 340.
https://scholarsrepository.llu.edu/fac_pubs/340