ABSTRACT
OBJECTIVE: Gestational diabetes mellitus (GDM) produces fetal hyperglycemia with increased lifelong risks for the exposed offspring of cardiovascular and other diseases. Epigenetic mechanisms induce long-term gene expression changes in response to in utero environmental perturbations. Moreover, microRNAs (miRs) control the function of endothelial cells (ECs) under physiological and pathological conditions and can target the epigenetic machinery. We investigated the functional and expressional effect of GDM on human fetal ECs of the umbilical cord vein (HUVECs). We focused on miR-101 and 1 of its targets, enhancer of zester homolog-2 (EZH2), which trimethylates the lysine 27 of histone 3, thus repressing gene transcription. EZH2 exists as isoforms α and ß. APPROACH AND RESULTS: HUVECs were prepared from GDM or healthy pregnancies and tested in apoptosis, migration, and Matrigel assays. GDM-HUVECs demonstrated decreased functional capacities, increased miR-101 expression, and reduced EZH2- ß and trimethylation of histone H3 on lysine 27 levels. MiR-101 inhibition increased EZH2 expression and improved GDM-HUVEC function. Healthy HUVECs were exposed to high or normal d-glucose concentration for 48 hours and then tested for miR-101 and EZH2 expression. Similar to GDM, high glucose increased miR-101 expression. Chromatin immunoprecipitation using an antibody for EZH2 followed by polymerase chain reaction analyses for miR-101 gene promoter regions showed that both GDM and high glucose concentration reduced EZH2 binding to the miR-101 locus in HUVECs. Moreover, EZH2-ß overexpression inhibited miR-101 promoter activity in HUVECs. CONCLUSIONS: GDM impairs HUVEC function via miR-101 upregulation. EZH2 is both a transcriptional inhibitor and a target gene of miR-101 in HUVECs, and it contributes to some of the miR-101-induced defects of GDM-HUVECs.
Subject(s)
Diabetes, Gestational/enzymology , Human Umbilical Vein Endothelial Cells/enzymology , MicroRNAs/metabolism , Polycomb Repressive Complex 2/metabolism , Apoptosis , Binding Sites , Case-Control Studies , Cell Movement , Cell Survival , Cells, Cultured , Diabetes, Gestational/genetics , Diabetes, Gestational/pathology , Diabetes, Gestational/physiopathology , Enhancer of Zeste Homolog 2 Protein , Female , Gestational Age , Glucose/metabolism , Histones/metabolism , Human Umbilical Vein Endothelial Cells/pathology , Humans , Methylation , Neovascularization, Physiologic , Phenotype , Polycomb Repressive Complex 2/genetics , Pregnancy , Promoter Regions, Genetic , RNA Interference , Signal Transduction , Time Factors , Transcription, Genetic , Transfection , Up-RegulationABSTRACT
INTRODUCTION: The accurate evaluation of tubal patency as well of the morphologic characteristics of the uterine cavity is a fundamental step in the diagnostic work-up for infertility. Hysteroscopy and laparoscopy and dye have long been regarded as the reference methods to assess uterine morphology and tubal patency, respectively. However, their technical and clinical limitations have supported the introduction of an emerging technique: hysterosalpingo contrast sonography (HyCoSy), which has recently been improved with the use of modern contrast agents and three-dimensional resolution. METHODS: A systematic literature search was performed in electronic databases (PubMed and Scopus). Key search terms included Hysterosalpingo contrast sonography (HyCoSy), Tubal patency, Infertility, Uterine cavity, Ultrasounds. RESULTS: HyCoSy has proved to be as reliable as laparoscopic techniques in the assessment of tubal patency and uterine morphology, and also it overcomes such major drawbacks as hospitalization, radiation exposure, anesthesia and use of iodinated contrast media. All in all, HyCoSy is considered as a safe and well tolerated outpatient procedure, which apparently favors the onset of spontaneous pregnancies. CONCLUSION: This paper provides a comprehensive overview of the literature dealing with HyCoSy to support its use as a first-line technique in standard infertility work-up.
