Transcriptional regulation of endothelial cell behavior during sprouting angiogenesis

Abstract

Mediating the expansion of vascular beds in many physiological and pathological settings, angiogenesis requires dynamic changes in endothelial cell behavior. However, the molecular mechanisms governing endothelial cell activity during different phases of vascular growth, remodeling, maturation, and quiescence remain elusive. Here, we characterize dynamic gene expression changes during postnatal development and identify critical angiogenic factors in mouse retinal endothelial cells. Using actively translating transcriptome analysis and in silico computational analyses, we determine candidate regulators controlling endothelial cell behavior at different developmental stages. We further show that one of the identified candidates, the transcription factor MafB, controls endothelial sprouting in vitro and in vivo, and perform an integrative analysis of RNA-Seq and ChIP-Seq data to define putative direct MafB targets, which are activated or repressed by the transcriptional regulator. Together, our results identify novel cell-autonomous regulatory mechanisms controlling sprouting angiogenesis.

A dynamic and integrated epigenetic program at distal regions orchestrates transcriptional responses to VEGFA

“…Our integrative transcriptional network analysis and subsequent validation experiments demonstrate that small MAFs have critical functions in angiogenesis by promoting endothelial cell migration, proliferation, and tube formation. This activity appears to be shared with other extended MAF family members, because MAFB, a large MAF factor, had been also recently found to activate vascular sprouting in rodents (Jeong et al 2017).…”

Apelin+ Endothelial Niche Cells Control Hematopoiesis and Mediate Vascular Regeneration after Myeloablative Injury

“…The analysis of rare recombined and therefore isolated GFP + cells indicates substantial changes in EC size and shape complexity at single-cell resolution ( Figures 1E and 1F). Next, we checked the density of ECs after irradiation, which was aided by Cdh5(PAC)-mtdTomato-nGFP (Cdh5-mTnG) reporter mice in which membrane-anchored tdTomato fluorescent protein labels the surface and histone H2B-coupled GFP (nGFP) the nuclei of ECs (Jeong et al, 2017) (Table S1). Confirming the specificity of this reporter, H2B-GFP signal co-localizes with nuclear ERG, a transcription factor and EC marker, in postnatal day (P) 6 heart endothelium but not in the EC-derived mesenchymal cell in heart valves (Figure S1E).…”

“…Cdh5(PAC)-mtdTomato-nGFP (Cdh5-mTnG) reporter mice were previously described and used for labeling of EC nuclei and FACS-sorting (Jeong et al, 2017).…”

Limbostomy: Longitudinal Intravital Microendoscopy in Murine Osteotomies

“…All animal experiments were approved by the local animal protection authority (LaGeSo Berlin; permission number G0302/17) following the German Animal Welfare Act. Cdh5‐GFP‐tdT mice express a membrane‐tagged tandem tomato fluorescent protein (tdT) and histone 2B linked enhanced green fluorescent protein (GFP) under a transgenic VE‐cadherin (Cdh5) promoter . Animals were bred in our colony and kept in a conventional specific pathogen‐free barrier facility.…”