High uniform fluid shear stress (FSS) is atheroprotective and preserves the endothelial phenotype and function through activation of downstream mediators such as MAPK7 (Erk5). Endothelial cells respond to FSS thanks to mechanotransduction. However, how the resulting signaling is integrated and resolved at the epigenetic level, remains elusive. We hypothesized that Polycomb methyltransferase EZH2 is involved in the effects of FSS in human endothelial cells. We showed that FSS decreases the expression of the Polycomb methyltransferase EZH2. Despite simultaneous activation of MAPK7, MAPK7 pathway does not directly influence the transcription of EZH2. Interestingly though, the knock down of EZH2 activates the protective MAPK7 signaling in endothelial cells, even in the absence of FSS. To understand the influence of the FSS-decreased expression of EZH2 on endothelial transcriptome, we performed RNA-seq and differential gene expression analysis. We identified candidate groups of genes dependent on both EZH2 and FSS. Among those, Gene Ontology overrepresentation analysis revealed highly significant enrichment of the cell cycle-related genes, suggesting changes in proliferation. Indeed, the depletion of EZH2 strongly inhibited endothelial proliferation, indicating cell cycle arrest. The concomitant decrease in CCNA expression suggests the transition of endothelial cells into a quiescent phenotype. Further bioinformatical analysis suggested TXNIP as a possible mediator between EZH2 and cell cycle-related gene network. Our data show that EZH2 is a FSS-responsive gene. Decreased EZH2 levels enhance the activation of the atheroprotective MAPK7 signaling. Decrease in EZH2 under FSS mediates the decrease in the expression of the network of cell cycle-related genes, which allows the cells to enter quiescence. EZH2 is therefore important for the protective effects of FSS in endothelium. Overall design: Puromycin-selected HUVEC (Human Umbilical Vein Endothelial Cells, Lonza, Switzerland) cells, expressing either scrambled control (SCR) or anti-EZH2 short-hairpin (shEZH2) constructs (at total 7 days after the first viral transduction), were used in FSS experiments (72h of control static culture or exposure to 20 dynes/cm2 of fluid shear stress, using Ibidi pump system (in µ-Slides I 0.4 Luer, Ibidi, Planegg/Martinsried, Germany)). Each replicate experiment consisted of viral transductions and puromycin selection of a separate HUVEC batch, followed by the FSS experiment. Two FSS experimental sets of the same HUVEC batch were run every time in parallel and lysed at the same end time point, one in RNAse-free conditions with RNA-Easy Mini Plus kit RLT Plus lysis buffer (QIAGEN, Venlo, The Netherlands), and one with RIPA buffer. The RIPA-lysates were analyzed with Western blotting and confirmed the complete (no protein present) knock-down of EZH2. From the RNA-lysates, RNA was isolated using the RNA-Easy Mini Plus kit (QIAGEN, Venlo, The Netherlands). High quality RNA samples (pre-assessed by Nanodrop measurements) were further processed in the Genome Analysis Facility of the University Medical Center Groningen. The RNA quality and integrity were verified using PerkinElmer Labchip GX with a cut-off value of 9 (scale 1 to 10, where 9 is very high quality RNA). RNA library was created in accordance with the TruSeqTM RNA Sample Preparation v2 Guide (Illumina, San Diego, CA, USA), using the PerkinElmer Sciclone liquid handler, resulting in 330bp cDNA fragments. The paired-end sequencing (100bp reads) was performed using the Illumina HiSeqTM 2500. (Quoted from the Materials and Methods of the related manuscript, with adjustments).
The decrease in histone methyltransferase EZH2 in response to fluid shear stress alters endothelial gene expression and promotes quiescence.
No sample metadata fields
View SamplesType I IFN-signaling suppresses an excessive IFN-{gamma} response and prevents lung damage and chronic inflammation following Pneumocystis (PC)-infection and clearance in CD4 T cell-competent mice.
Type-I IFN signaling suppresses an excessive IFN-gamma response and thus prevents lung damage and chronic inflammation during Pneumocystis (PC) clearance in CD4 T cell-competent mice.
Specimen part
View SamplesHyperglycemia is an essential factor leading to micro- and macrovascular diabetic complications. Macrophages are key innate immune regulators of inflammation that undergo 2 major directions of functional polarization: classically (M1) and alternatively (M2) activated macrophages. The aim of the study was to examine the effect of hyperglycemia on transcriptional activation of M0, M1 and M2 human macrophages.
Hyperglycemia induces mixed M1/M2 cytokine profile in primary human monocyte-derived macrophages.
Specimen part, Treatment, Subject
View SamplesDerivation and expansion of human umbilical cord blood-derived endothelial colony forming cells under serum-free conditions - a transcriptome analysis.
Optimization of the culturing conditions of human umbilical cord blood-derived endothelial colony-forming cells under xeno-free conditions applying a transcriptomic approach.
Specimen part
View SamplesMost higher organisms, including plants and animals, have developed a time-keeping mechanism that allows them to anticipate daily fluctuations of environmental parameters such as light and temperature. This circadian clock efficiently coordinates plant growth and metabolism with respect to time-of-day by producing self-sustained rhythms of gene expression with an approximately 24-hour period. The importance of these rhythms has in fact been demonstrated in both phytoplankton and higher plants: organisms that have an internal clock period matched to the external environment possess a competitive advantage over those that do not.
The circadian clock regulates auxin signaling and responses in Arabidopsis.
No sample metadata fields
View SamplesOsteoblasts are key players in bone remodeling. The accessibility of human primary osteoblast-like cells (HOb) from bone explants render them a lucrative model for studying molecular physiology of bone turnover, discovery of novel anabolic therapeutics and mesenchymal cell biology in general. Relatively little is known about resting and dynamic expression profiles of HObs and no studies have been conducted to date to systematically assess the osteoblast transcriptome. The aim of this study was to characterize HObs and investigate signaling cascades and gene networks using genomewide expression profiling in resting and Bone Morphogenic Protein (BMP)-2 and Dexamethasone induced cells.
Systematic assessment of the human osteoblast transcriptome in resting and induced primary cells.
No sample metadata fields
View SamplesThe hypocotyl of Arabidopsis seedlings shows rhythmic periods of elongation. The patterns of elongation are controlled by a combination of internal factors, such as the circadian clock, and external factors such as light. In a previous study we had found that two transcription factors, PIF4 and PIF5 are important integrators of clock and light signals for the control of elongation. Here we use microarrays to find genes that are correlated with elongation and that are controlled by PIF4 and/or PIF5.
Genomic analysis of circadian clock-, light-, and growth-correlated genes reveals PHYTOCHROME-INTERACTING FACTOR5 as a modulator of auxin signaling in Arabidopsis.
No sample metadata fields
View SamplesTranscription factor FoxQ1 belongs to family of Fox transcription factors containing forkhead box (winged helix) domain. This family of proteins plays an important role in cell growth, proliferation, and differentiation. Expression of FoxQ1 was found in cancer cells and was associated with increased migration and invasion. Recently, elevated FoxQ1 expression was found in IL4 stimulated macrophages.
IL-4 driven transcription factor FoxQ1 is expressed by monocytes in atopic dermatitis and stimulates monocyte migration.
Cell line
View SamplesPseudomonas aeruginosa (P. aeruginosa) lung infection is a significant cause of mortality in patients with cystic fibrosis (CF). Existing experimental data in our lab showed significantly different levels of virulence of "early" and "late" P. aeruginosa infection isolates in a C. elegans slow killing model. We wished to examine the expression profile of these isolates in order to explore genes that may be responsible for the observed differences. The expression profiles of two pairs of isolates (four isolates in total) were compared to each other using the Affymetrix P. aeruginosa PAO1 genome array, to gain insight into properties mediating virulence in these isolates. Data analysis was carried out using BIOCONDUCTOR software.
Modulation of gene expression by Pseudomonas aeruginosa during chronic infection in the adult cystic fibrosis lung.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
PRDM16 represses the type I interferon response in adipocytes to promote mitochondrial and thermogenic programing.
Specimen part
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