Search bioRxiv⌕ Search

Biology subjects

McVey, D. G.

Publications and source records attributed to McVey, D. G..

4 recordsLinked to original sources

Dissecting the Cellular Genetics of Cardiovascular Disease Through Endothelial and Immune Compartments Profiling

BackgroundNon-communicable diseases such as coronary artery disease, atrial fibrillation, type 2 diabetes, hypertension, and others share endothelial dysfunction as one of their underlying features. The endothelium, as the interface between blood and vasculature, shapes disease onset and progression through its response to environmental cues. However, while the genetic component of these diseases has been captured by genome wide association studies (GWAS), which also highlighted a shared immune component, it remains unclear which of these disease loci exerts their effects through endothelial cells. This study identifies, and quantifies, the genetic determinants of endothelial cells molecular traits and their overlap to the common genetic variation component of these diseases. MethodsWe generated genotype, RNA-sequencing, H3K27ac ChIP-sequencing, ATAC-sequencing, and endothelial cells barrier stimuli response measurements for 100 samples of human umbilical vein endothelial cells. These were used to identify quantitative trait loci (QTL) for gene expression, transcriptional isoform usage, splice junction usage, chromatin activity and barrier response. We applied statistical colocalisation to identify the overlap between data layers, and to explain molecular QTLs contribution to GWAS disease loci. ResultsWe used molecular QTLs to identify the regulatory features of 8,214 genes, representing 36% of all expressed genes in endothelial cells. We also identified the molecular mechanisms underlying 815 loci across 16 disease GWAS. These represent between 29% and 40% of all loci for each disease, compared to the previous average of 23%. This is due to the choice of a cell type often underrepresented in tissue level data, and the inclusion of isoform, splicing and chromatin activity datasets. Furthermore, we compared the endothelial cells molecular QTLs with similar datasets in monocytes, neutrophils and CD4 T lymphocytes to shed light on the interplay between the endothelial and the immune compartments in these diseases. We identified loci acting through both the endothelial and the immune compartment, mostly with the same directionality of effect, and endothelial specific ones. ConclusionsThis work expands the knowledge of the mechanisms and genes underlying the effect of common genetic variation on non-communicable diseases having endothelial dysfunction as a shared feature. It also illustrates the interplay between endothelial cells and immune cell types in these diseases, highlighting shared and unique pathways.

genomics↗

Oscillatory and elevated flow distinctly regulate gene expression in human coronary artery endothelial cells

BackgroundAtherosclerosis develops at arterial sites exposed to disturbed flow, while plaque rupture and plaque erosion predominantly occur in regions subjected to elevated flow. The impact of elevated flow on regulation of endothelial gene expression is less well studied; therefore, we undertook a comprehensive analysis of primary human coronary artery endothelial cell (HCAEC) gene expression under elevated flow, comparing it to gene expression induced by normal physiological and oscillatory flow. MethodsAnalysis of HCAEC mRNA, microRNA and protein expression cultured under oscillatory shear stress (OSS), physiological laminar shear stress (LSS), and elevated shear stress (ESS) for 72 hours. Identification of changes in RNA isoform expression and proximity of flow-responsive genes to established coronary artery disease (CAD) risk loci were also performed. Results2,175 shear-regulated genes were identified, with 665 uniquely responsive to ESS. Both ESS and OSS induced significant changes in RNA isoform selection, predicted to affect 848 and 580 genes respectively. Signalling pathways regulating CAD pathogenesis including HIPPO, TGF{beta}/BMP, and IRF, showed altered RNA isoform selection which may influence plaque development and plaque erosion. 65% of linkage disequilibrium (LD)-filtered CAD-associated genetic variants contained at least one OSS or ESS-regulated gene within 250Kb. Proteomic analysis identified 289 proteins differentially expressed under OSS and 171 under ESS, with notable discordance between mRNA and protein changes observed in 28.7% (OSS vs LSS) and 16.6% (ESS vs LSS) genes. Additionally, 40 shear-responsive microRNAs were identified. ConclusionElevated flow elicits a distinct gene expression programme in HCAECs, modulating pathways central to CAD pathogenesis. Research PerspectiveWhat New Question Does This Study Raise? O_LIPlaque erosion predominantly occurs on the upstream surface of the plaque, where the endothelium is exposed to elevated flow, which we show within this study to evoke a significant and largely unique regulation of the transcriptome, miRome and proteome within primary human coronary artery endothelial cells. C_LIO_LIIdentify shear stress as a significant regulator of alternative splicing, with elevated flow causing the greatest shift in alternative transcript selection. C_LIO_LIIdentify 135 oscillatory, and 101 elevated differentially expressed genes in proximity to CAD risk loci. C_LI What Question Should be Addressed Next? O_LIStudy of the response of the coronary endothelium directly in patients to understand how the risk factors involved in plaque erosion change endothelial function. C_LIO_LICreation of physiological 3D arterial models replicating in vivo observations to study the precipitating factors involved in plaque erosion. C_LI

cell biology↗

Allele-specific epigenetic regulation of FURIN expression at a coronary artery disease susceptibility locus

BackgroundGenome-wide association studies have revealed an association between the genetic variant rs17514846 on chromosome 15q26.1 and coronary artery disease susceptibility. Studies have shown that rs17514846 influences the expression of the FES Upstream Region (FURIN) gene located at this locus in monocytes. We investigated the mechanism through which rs17514846 modulates FURIN expression. Methods and ResultsAn analysis of isogenic monocytic cell lines with either the rs17514846 C/C or A/A genotype showed that the cells of the A/A genotype expressed higher levels of FURIN than cells of the C/C genotype. A pyrosequencing methylation analysis showed that the cytosine (in a CpG motif) at the rs17514846 position on the C allele was methylated. Treatment with the DNA methylation inhibitor 5-aza-2-deoxycytidine increased FURIN expression. A bioinformatic analysis indicated that the rs17514846 site might interact with the transcription factor MeCP2 that often functions as a gene repressor by binding to methylated CpG sites. An electrophoretic mobility super-shift assay with a probe corresponding to the DNA sequence at and around the rs17514846 position of the C allele detected two DNA-protein complex bands, which were altered by the addition of an anti-MeCP2 antibody in the assay, whilst these DNA-protein complexes were barely detectable with a probe for the A allele. A chromatin immunoprecipitation assay showed an enrichment of the DNA sequence containing the rs17514846 site in chromatin precipitates pulled down by an anti-MeCP2 antibody. siRNA-mediated knockdown of MeCP2 caused an increase in FURIN expression. Furthermore, MeCP2 knockdown increased monocyte migration and proliferation, and this effect was diminished by a FURIN inhibitor. ConclusionsThe results of our study suggest that DNA methylation inhibits FURIN expression and that the coronary artery disease predisposing variant rs17514846 modulates FURIN expression and monocyte migration via an allele-specific effect on DNA methylation.

genetics↗

Identification and Characterization of novel long non-coding RNAs in vascular smooth cells

A significant portion of the RNA produced from the human genome consists of long non-coding RNAs (lncRNAs). These molecules tend to have lower levels of expression, are more specific to certain tissues, and show greater variation in expression between individuals compared to protein-coding messenger RNAs (mRNAs). LncRNAs have been linked with regulatory roles in gene expression and genome architecture. There is growing evidence that lncRNAs play important roles in many biological processes and diseases, and a number of lncRNAs have been identified as potential therapeutic targets. Here, we report the identification and characterization of the lncRNA landscape of vascular smooth muscle cells (VSMC). We used an ensemble of bioinformatics tools to identify 329 novel lncRNAs from a large VSMC RNA-Seq dataset. We found that majority of the novel lncRNAs are natural antisense transcripts of protein-coding genes. In addition, we predicted cellular localization and potential miRNAs that targets the novel lncRNAs and found that most localize in the cytoplasm and that miRNA target site ranged from 2-889 sites on each novel lncRNA. Furthermore, we identified co-expressed lncRNAs that correlate with the proliferation, migration and apoptosis of vascular smooth muscle cells. These results suggest that we have identified a diverse set of previously unknown lncRNAs that may be involved in important regulatory pathways in vascular smooth muscle cells.

bioinformatics↗