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Vascular endothelial growth factor A (VEGF-A) is a master regulator of angiogenesis, vascular development and function. In this study we investigated the transcriptional regulation of VEGF-A-responsive genes in primary human aortic endothelial cells (HAECs) and human umbilical vein endothelial cells (HUVECs) using genome-wide global run-on sequencing (GRO-Seq). We demonstrate that half of VEGF-A-regulated gene promoters are characterized by a transcriptionally competent paused RNA polymerase II (Pol II). We show that transition into productive elongation is a major mechanism of gene activation of virtually all VEGF-regulated genes, whereas only ∼40% of the genes are induced at the level of initiation. In addition, we report a comprehensive chromatin interaction map generated in HUVECs using tethered conformation capture (TCC) and characterize chromatin interactions in relation to transcriptional activity. We demonstrate that sites of active transcription are more likely to engage in chromatin looping and cell type-specific transcriptional activity reflects the boundaries of chromatin interactions. Furthermore, we identify large chromatin compartments with a tendency to be coordinately transcribed upon VEGF-A stimulation. We provide evidence that these compartments are enriched for clusters of regulatory regions such as super-enhancers and for disease-associated single nucleotide polymorphisms (SNPs). Collectively, these findings provide new insights into mechanisms behind VEGF-A-regulated transcriptional programs in endothelial cells.

Aims Oxidized phospholipids and microRNAs (miRNAs) are increasingly recognized to play a role in endothelial dysfunction driving atherosclerosis. NRF2 transcription factor is one of the key mediators of the effects of oxidized phospholipids, but the gene regulatory mechanisms underlying the process remain obscure. Here, we investigated the genome-wide effects of oxidized phospholipids on transcriptional gene regulation in human umbilical vein endothelial cells and aortic endothelial cells with a special focus on miRNAs. Methods and results We integrated data from HiC, ChIP-seq, ATAC-seq, GRO-seq, miRNA-seq, and RNA-seq to provide deeper understanding of the transcriptional mechanisms driven by NRF2 in response to oxidized phospholipids. We demonstrate that presence of NRF2 motif and its binding is more prominent in the vicinity of up-regulated transcripts and transcriptional initiation represents the most likely mechanism of action. We further identified NRF2 as a novel regulator of over 100 endothelial pri-miRNAs. Among these, we characterize two hub miRNAs miR-21-5p and miR-100-5p and demonstrate their opposing roles on mTOR , VEGFA , HIF1A , and MYC expressions. Finally, we provide evidence that the levels of miR-21-5p and miR-100-5p in exosomes are increased upon senescence and exhibit a trend to correlate with the severity of coronary artery disease. Conclusion Altogether, our analysis provides an integrative view into the regulation of transcription and miRNA function that could mediate the proatherogenic effects of oxidized phospholipids in endothelial cells. [ABSTRACT FROM AUTHOR]

Aims: Risk assessment is essential in the prevention of cardiovascular disease. In patients with recent acute coronary syndrome (ACS) or coronary revascularization, risk prediction tools, like the European Society of Cardiology guideline recommended SMART-REACH risk score, are increasingly used to predict the risk of recurrent cardiovascular events enabling risk-based personalized prevention. However, little is known about the association between risk stratification and the social and healthcare costs at a population level. This study evaluated the associations between baseline SMART-REACH risk scores, long-term recurrent clinical events, cumulative costs, and post-index event LDL-C goal attainment in patients with recent ACS and/or revascularization., Methods and Results: This retrospective study used electronic health records and was conducted in the North Karelia region of Finland. The study cohort included all patients aged 45-85 admitted to a hospital for ACS or who underwent percutaneous coronary intervention or coronary artery bypass surgery between 1 January 2017 and 31 December 2021. Patients were divided into quintiles based on their baseline SMART-REACH risk scores to examine the associations between predicted 5-year scores and selected clinical and economic outcomes. In addition, simple age-based stratification was conducted as a sensitivity analysis. The observed 5-year cumulative incidence of recurrent events ranged from 20% in the lowest to 41% in the highest risk quintile, whereas the corresponding predicted risks ranged from 13% to 51%, and cumulative 5-year mean total costs per patient ranged from 15 827 to 46 182€, respectively. Both monitoring and attainment of low LDL-C values were suboptimal., Conclusion: The use of the SMART-REACH quintiles as a population-level risk stratification tool successfully stratified patients into subgroups with different cumulative numbers of recurrent events and cumulative total costs. However, more research is needed to define clinically and economically optimal threshold values for a population-level stratification., Competing Interests: Conflict of interest: M.O. and C.A. are employees of ESiOR Oy. At the time of writing, J.P. was an employee of ESiOR Oy. J.P. is no longer an employee of ESiOR Oy. J.M. is a founding partner and shareholder of ESiOR Oy. A.K. is an employee of Novartis. Other declare no competing interest to the current study., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)