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Biology subjects

van den Dungen, N. A. M.

Publications and source records attributed to van den Dungen, N. A. M..

3 recordsLinked to original sources

Identification of endothelial-to-mesenchymal transition gene signatures in single-cell transcriptomics of human atherosclerotic tissue

RationaleEndothelial cells can differentiate into mesenchymal-like cells via endothelial to mesenchymal transition (EndoMT). In murine models, cell transitions of EndoMT have been assessed with lineage tracing techniques. Knowledge on molecular mechanisms of EndoMT in human vascular lesions is scarce as studies in human atherosclerosis are limited by observational study designs such as histo-pathological studies. ObjectiveWe aim to identify a human EndoMT gene expression signature by combining experimentally induced in vitro EndoMT with lineage-traced pathways from atherosclerotic mice and extrapolate this to human plaque scRNA-seq data. Methods and resultsFirst, we stimulated human coronary artery endothelial cells (HCAEC) with TNF and TFG{beta} to trigger EndoMT. We executed transcriptomic analyses and defined multiple temporal patterns of gene expression changes during EndoMT. We used Cdh5-CreERT2 Rosa-eYFP apoE-/- lineage traced mouse scRNA-seq data to demonstrate that the temporal in vitro gene expression changes are reflected in EndoMT trajectories in mice plaque tissue. Finally, we constructed three candidate EndoMT lineages across multiple subpopulations of ECs and SMCs in human carotid scRNA-seq data (n=46). We examined gene expression over the course of these lineages and identified 73 markers for the presence of EndoMT such as NRG1 and DEPP1. ConclusionThis study reveals the gene expression profile of EndoMT trajectories in human atherosclerotic plaques by combining RNA-seq data from in vitro models with single-cell transcriptomic datasets. Our gene expression atlas of EndoMT in atherosclerosis could serve as a reference for future studies, providing novel inroads to study atherosclerotic mechanisms for the development of novel therapies.

molecular biology↗

Human primary plaque cell cultures to study mechanisms of atherosclerosis

Plaque smooth muscle cells are critical players in the initiation and advancement of atherosclerotic disease. They produce extracellular matrix (ECM) components, which play a role in lesion progression and stabilization. Despite clear phenotypic differences between plaque smooth muscle cells and vascular smooth muscle cells (VSMCs), VSMCs are still widely used as a model system in atherosclerotic research. Here we present a conditioned outgrowth method to isolate plaque smooth muscle cells. We obtained plaque cells from 27 donors (24 carotid and 3 femoral endarterectomies). We show that these cells keep their proliferative capacity for eight passages, are transcriptionally stable, retain donor-specific gene expression programs, and express extracellular matrix proteins (FN1, COL1A1, DCN) and smooth muscle cell markers (ACTA2, MYH11, CNN1). Single-cell transcriptomics of plaque tissue and cultured cells reveals that cultured plaque cells closely resemble the myofibroblast fraction of plaque smooth muscle cells. Chromatin immunoprecipitation sequencing (ChIP-seq) shows the presence of histone H3 lysine 4 dimethylation (H3K4me2) at the MYH11 promoter, pointing to their smooth muscle cell origin. Finally, we demonstrated that plaque cells can be efficiently transduced (>97%) and are capable to take up oxidized LDL (oxLDL) and undergo calcification. In conclusion, we present a method to isolate and culture primary human plaque cells that retain plaque myofibroblast-like cells phenotypical and functional capabilities - making them a suitable in vitro model for studying selected mechanisms of atherosclerosis.

cell biology↗

Locational memory of macrovessel vascular cells is transcriptionally imprinted

The locational predisposition of vascular pathologies illustrates the need for a better insight into vascular heterogeneity. To investigate the transcriptomic basis of angiodiversity, we isolated and analyzed transcriptomes from endothelial cells and vascular smooth muscle cells from nine different adult canine macrovessels: the aorta, coronary artery, vena cava, portal vein, femoral artery, femoral vein, saphenous vein, pulmonary vein, and pulmonary artery. We identified both reported and novel expression patterns defining specialized adult blood vessels. Our findings also show that adult vascular cells in culture express a remarkably high number of transcription factors crucial to organ development in the embryo. The persistent expression of these genes in culture indicates that these genes are not regulated by the flow or surrounding cell types but are rather fixed in the molecular memory. Therefore, our findings prompt the re-thinking of the extrapolation of results from single-origin endothelial cell systems.

cell biology↗