CpG signalling, H2A.Z/H3 acetylation and microRNA-mediated deferred self-attenuation orchestrate foetal NOS3 expression

Abstract

BackgroundAn adverse intrauterine environment leads to permanent physiological changes including vascular tone regulation, potentially influencing the risk for adult vascular diseases. We therefore aimed to monitor responsive NOS3 expression in human umbilical artery endothelial cells (HUAEC) and to study the underlying epigenetic signatures involved in its regulation.ResultsNOS3 and STAT3 mRNA levels were elevated in HUAEC of patients who suffered from placental insufficiency. 5-hydroxymethylcytosine, H3K9ac and Histone 2A (H2A).Zac at the NOS3 transcription start site directly correlated with NOS3 mRNA levels. Concomitantly, we observed entangled histone acetylation patterns and NOS3 response upon hypoxic conditions in vitro. Knock-down of either NOS3 or STAT3 by RNAi provided evidence for a functional NOS3/STAT3 relationship. Moreover, we recognized massive turnover of Stat3 at a discrete binding site in the NOS3 promoter. Interestingly, induced hyperacetylation resulted in short-termed increase of NOS3 mRNA followed by deferred decrease indicating that NOS3 expression could become self-attenuated by co-expressed intronic 27 nt-ncRNA. Reporter assay results and phylogenetic analyses enabled us to propose a novel model for STAT3-3′-UTR targeting by this 27-nt-ncRNA.ConclusionsAn adverse intrauterine environment leads to adaptive changes of NOS3 expression. Apparently, a rapid NOS3 self-limiting response upon ectopic triggers co-exists with longer termed expression changes in response to placental insufficiency involving differential epigenetic signatures. Their persistence might contribute to impaired vascular endothelial response and consequently increase the risk of cardiovascular disease later in life.Electronic supplementary materialThe online version of this article (doi:10.1186/s13148-014-0042-4) contains supplementary material, which is available to authorized users.

N‐Acetylcysteine, a glutathione precursor, reverts vascular dysfunction and endothelial epigenetic programming in intrauterine growth restricted guinea pigs

“…) and pre‐term (Postberg et al . ) is characterized by an increased expression of eNOS mRNA with a parallel increase in eNOS protein levels, but a significant decrease in activating post‐translational modifications (Krause et al . a ).…”

Adult vascular dysfunction in foetal growth‐restricted guinea‐pigs is associated with a neonate‐adult switching in Nos3 DNA methylation

“…Conversely, studies in animal models show that foetal exposure to hypoxia or a suboptimal uteroplacental perfusion induces a DNA methylation‐mediated eNOS upregulation, but impaired endothelial function in foetal systemic and umbilical arteries. Similarly, human umbilical artery endothelial cells from pregnancies affected by FGR show an increased eNOS expression that results from permissive histone post‐translational modifications, as well as DNMT1‐mediated decreased NOS3 promoter DNA methylation . However, no studies have determined whether this altered epigenetic programming of eNOS expression is preserved until adulthood.…”

“…For instance, a decreased endothelial function is observed in small for gestational age neonates, as well as in umbilical and chorionic arteries derived from FGR placentas . These traits of FGR‐associated endothelial dysfunction persist in vitro, characterized by altered expression of proteins involved in NO‐dependent vasodilation (ie, eNOS and arginase). Specifically, altered expression of eNOS in FGR‐derived endothelium results from diverse epigenetic modifications in the NOS3 gene promoter, an effect that can be reprogrammed to a “normal type” by knocking‐down DNMT1 .…”

“…These traits of FGR‐associated endothelial dysfunction persist in vitro, characterized by altered expression of proteins involved in NO‐dependent vasodilation (ie, eNOS and arginase). Specifically, altered expression of eNOS in FGR‐derived endothelium results from diverse epigenetic modifications in the NOS3 gene promoter, an effect that can be reprogrammed to a “normal type” by knocking‐down DNMT1 . Additionally, we recently reported that FGR results in an altered eNOS expression and Nos3 gene promoter DNA methylation in a guinea‐pig model of FGR, which is comparable between foetal systemic and umbilical arteries .…”

Downregulation of MicroRNA-152 contributes to high expression of DKK1 in multiple myeloma

“…that predominantly determines cell survival and malignant transformation. [35][36][37] So far, a specific role for miR-152 and a relationship with DKK1 in MM has not been described.…”