MiR-21-5p directly contributes to regulating eNOS expression in human artery endothelial cells under normoxia and hypoxia

• Published in: Biochemical pharmacology 2020-12, Vol.182, p.114288-114288, Article 114288
• Main Authors: Peñaloza, Estefania, Soto-Carrasco, Gustavo, Krause, Bernardo J.
• Format: Article
• Language: English
• Subjects: Cell Hypoxia - physiology; Cells, Cultured; DNA methylation; Endothelium, Vascular - metabolism; Female; Fetal growth restriction; Gene Expression Regulation, Enzymologic; Humans; Hypoxia; Infant, Newborn; Male; MicroRNAs - antagonists & inhibitors; MicroRNAs - metabolism; miRNA; Nitric oxide; Nitric Oxide Synthase Type III - biosynthesis; Nitric Oxide Synthase Type III - genetics; Oxidative stress; Pregnancy; Umbilical Arteries - metabolism
• ISSN: 0006-2952; 1873-2968
• DOI: 10.1016/j.bcp.2020.114288

Proposed mechanism of miR-21-5p regulation by hypoxia and its contribution to regulation of eNOS and DDHA1 in response to acute and chronic exposure to low oxygen levels in human umbilical artery endothelial cells. [Display omitted] Clinical conditions associated with hypoxia and oxidative stress, such as fetal growth restriction (FGR), results in endothelial dysfunction. Previous reports show that changes in eNOS expression under these conditions are tightly controlled by DNA methylation and histone posttranslational modifications. However, the contribution of an orchestrating epigenetic mechanism, such as miRNAs, on the NO-related genes expression has not been addressed. We aimed to determine the levels of miRNAs highly expressed in normal endothelial cells (EC), miR-21 and miR-126, in FGR human umbilical artery EC (HUAEC), and their effects on hypoxia-dependent regulation of both, NO-related and oxidative stress-related genes. Results were validated by transcriptome analysis of HUAEC cultured under chronic low oxygen conditions. Cultured FGR-HUAEC showed decreased hsa-miR-21, DDAH1, SOD1, and NRF2, but increased miR-126, NOX4, and eNOS levels, compared with controls. MiR-21-5p levels in FGR were associated with increased hg-miR-21 gene promoter methylation, with no changes in hg-miR-126 gene promoter methylation. HUAEC exposed to hypoxia showed a transient increase in eNOS and DDAH11, paralleled by decrease miR-21-5p levels, but no changes in miR-126-3p and the other genes under study. Transcriptome profiling showed an inverse relationship among miR-21 and several transcripts targeted by miR-21 in HUAEC exposed to hypoxia, meanwhile miR-21-5p-mimic decreased eNOS and DDAH1 transcripts stability, blocking their induction by hypoxia. Consequently, FGR programs a hypoxia-related miRNA that contributes to the regulation of the NO pathway, involving a direct effect of miR-21-5p on eNOS transcript stability, not previously reported. Moreover, hypoxia downregulates miR-21-5p, contributing to increasing the expression of NO-related genes in arterial endothelial cells.