Endothelial Response to Increased Shear Stress Frequency
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ABSTRACT:
ORGANISM(S): Sus scrofa
SUBMITTER: Ji Zhang
PROVIDER: E-GEOD-26513 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:In this study, we characterized the adaptive response of arterial endothelial cells to acute increases in shear stress magnitude in well-defined in vitro settings. Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dynes/cm2 at 1 Hz for 24 hours, and an acute increase in shear stress magnitude (30 ± 15 dynes/cm2) was then applied. The transcriptomics studies using microarray identified genes that were sensitive to the elevated shear magnitude. A significant number of the identified genes in our study are previously unknown as sensitive to shear stress. Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dynes/cm2 at 1 Hz for 24 hours, and an acute increase in shear stress magnitude (30 ± 15 dynes/cm2) was then applied. Gene expression at multiple time points was measured using microarray.
2011-12-01 | E-GEOD-26505 | biostudies-arrayexpress
Project description:Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dynes/cm2 at 1 Hz for 24 hours, and an acute increase in shear stress frequency (2 Hz) was then applied. The transcriptomics studies using microarray identified genes that were sensitive to the elevated shear frequency. keywords: adaptation, shear stress, frequency, microarray, gene expression
2011-12-01 | GSE26513 | GEO
Project description:In this study, we characterized the adaptive response of arterial endothelial cells to acute increases in shear stress magnitude in well-defined in vitro settings. Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dynes/cm2 at 1 Hz for 24 hours, and an acute increase in shear stress magnitude (30 ± 15 dynes/cm2) was then applied. The transcriptomics studies using microarray identified genes that were sensitive to the elevated shear magnitude. A significant number of the identified genes in our study are previously unknown as sensitive to shear stress.
2011-12-01 | GSE26505 | GEO
Project description:This study characterizes the response of primary human endothelial cells (human umbilical vein endothelial cells, HUVECs) to the relative shear stress changes that occur during the initiation of arteriogenesis at the entrance regions to a collateral artery network. HUVECs were preconditioned to a baseline level of unidirectional shear of 15 dynes/cm2 for 24 hours. After 24 hours preconditioning, HUVECs were subjected to an arteriogenic stimulus that mimics the shear stress changes observed in the opposing entrance regions into a collateral artery network. The arteriogenic stimulus consisted of a 100% step wise increase in shear stress magnitude to a unidirectional 30 dynes/cm2 in either the same or opposite direction of the preconditioned shear stress. This simulates either the feeding entrance to the collateral artery circuit or the region that drains into the vasculature downstream of an obstruction in a major artery, respectively. In vivo analysis of collateral growth in the mouse hindlimb showed enhanced outward remodeling in the re-entrant (direction reversing) region that reconnects to the downstream arterial tree, suggesting reversal of shear stress direction as a key enhancer of arteriogenesis. Transcriptional profiling using microarray techniques identified that the reversal of shear stress direction, but not an increase in shear stress alone, yielded a broad-based enhancement of the mechanotransduction pathways necessary for the induction of arteriogenesis. Human umbilical vein endothelial cells (HUVECs) were preconditioned to a unidirectional clockwise shear stress of 15 dynes/cm2 for 24 hours. An acute increase in shear stress magnitude to 30 dynes/cm2 in either a clockwise (non-reversed) or counter-clockwise (reversed) direction was applied for 6 hours. An additional preconditioned control culture was maintained under a unidirectional clockwise shear stress of 15 dynes/cm2 and harvested at the same time point, 6 hours post-conditioning. Each condition of reversed, non-reversed, and control was performed in tandem from the same starting cell culture as one replicate. The total experiment consisted of four replicates. Gene transcription was then assessed using microarray expression analysis.
2016-04-01 | E-GEOD-46248 | biostudies-arrayexpress
Project description:To investigate the function of oscillating shear stress in the regulation of endothelial progenitor cell (EPCs) differentiation, we used EPCs derived from the umbilical cord blood loaded with OSS for 12h. OSS (±3.5 dynes/cm2, 1 Hz frequency) was loaded using a Flexcell flow STR-4000 parallel plate flow chamber system.
2022-08-19 | GSE211402 | GEO
Project description:In order to simulate the effects of shear stress in regions of the vasculature prone to developing atherosclerosis, we subjected human umbilical vein endothelial cells to reversing shear stress, in order to mimic hemodynamic conditions at the wall of the carotid sinus, a site of complex, reversing blood flow and commonly observed atherosclerosis. We compared the effects of reversing shear stress (time-average 1 dyne/cm2, maximum +11 dynes/cm2, minimum -11 dynes/cm2, 1 Hz), arterial steady shear stress (15 dynes/cm2), and low steady shear stress (1 dyne/cm2) in terms of gene expression, cell proliferation, and monocyte adhesiveness. Microarray analysis revealed most differentially expressed genes were similarly regulated by all three shear stress regimens when compared to static culture. Comparisons of the three shear stress regimens to each other allowed identification of 138 genes regulated by low average shear stress and 22 by fluid reversal. Functional assays indicated that low average shear stress induces increased cell proliferation as compared to high shear stress. Reversing shear stress was the only condition that induced monocyte adhesion. Monocyte adhesion was partially inhibited by incubation of the endothelial cells with ICAM-1 blocking antibody. Increased surface heparin sulfate proteoglycan expression was observed in cells exposed to reversing shear stress. When these cells were treated with heparinase III monocyte adhesion was significantly reduced. Our results suggest that low steady shear stress is the major impetus for differential gene expression and cell proliferation, while reversing flow regulates monocyte adhesion.
2009-11-16 | GSE16706 | GEO
Project description:We are interested in the role of NOTCH1 and Shear Stress in Aortic Valve Endothelium. Primary human aortic valve endothelium was subjected to 4 conditions in vitro. 1) Control siRNA, No shear stress. 2) NOTCH1 siRNA, No shear stress. 3) Control siRNA, 15 dynes/cm2 shear stress. 4) NOTCH1 siRNA, 15 dynes/cm2 shear stress. Triplicates of each condition were pooled for library perp and sequencing
2015-05-16 | E-GEOD-47157 | biostudies-arrayexpress
Project description:The arterial endothelium’s response to its flow environment is critical to vascular homeostasis. The endothelial glycocalyx has been shown to play a major role in mechanotransduction, but the extent to which the components of the glycocalyx affect the overall function of the endothelium remains unclear. The objective of this study was to further elucidate the role of heparan sulfate as a mechanosensor on the surface of the arterial endothelium, by (1) expanding the variety of shear waveforms investigated, (2) continuously suppressing heparan sulfate expression rather than using a pre-flow batch treatment, and (3) performing microarray analysis on post-flow samples. Porcine aortic endothelial cells were exposed to non-reversing, reversing, and oscillatory shear waveforms for 24 hours with or without continuous heparan sulfate suppression with heparinase. All shear waveforms significantly increased the amount of heparan sulfate on the surface of the endothelium. Suppression of heparan sulfate to less than 25% of control levels did not inhibit shear-induced cell alignment or nitric oxide production, or alter gene expression, for any of the shear waveforms investigated. We infer that heparan sulfate on the surface of porcine aortic endothelial cells is not the primary mechanosensor for many shear-responsive endothelial cell functions in this species. Porcine aortic endothelial cells were exposed to 3 different shear waveforms for 24 hours with or without the addition of 300 mU/ml heparinase III to the flow media. The shear waveforms inculded Non-reversing (15 ± 15 dyne/cm2, 1 Hz), Steady (15 dyne/cm2), or Oscillatory (0 ± 15 dyne/cm2, 1 Hz) shear. Four replicates of each condition were performed for a total of 24 experiments. Each experimental sample was hybridized to an oligonucleotide array along with a standard reference sample (static cells).
2011-07-21 | E-GEOD-30843 | biostudies-arrayexpress
Project description:The objective of this study was to advance the understanding of how in vivo arterial shear forces affect vascular endothelial gene expression. Complicated blood flow patterns at arterial branches create small regions that experience fluctuations in shear stress at frequencies higher than the heart rate. To assess whether such temporal variations in shear stress can affect endothelial gene expression, a series of in vitro microarray experiments was performed. The effects of three sinusoidal waveforms (1, 2, and 3 Hz) and one physiological waveform were compared to the expression profiles under steady flow. At each frequency, three levels of mean shear stress (0, 7.5, and 15 dyn/cm2) were used. Porcine aortic endothelial cells were exposed for 24 hours to each combination, replicated four times. Following shear exposure, phase contrast images of the cells were acquired, and RNA was extracted for microarray analysis against about 10,000 porcine oligonucleotides. Cell alignment with the flow was positively correlated with mean shear (p < 0.001) and independent of frequency. A two-way ANOVA identified 232 genes that were differentially regulated by frequency. The frequency sensitive genes were clustered to identify groups of genes exhibiting similar frequency responses. The largest response was seen at 2 Hz. At this frequency, several inflammatory molecules were upregulated, including VCAM, CTGF, TGF-beta2, c-jun, and IL-8, indicating a potential endothelial atherosusceptibility at this frequency. Mean shear significantly affected the expression of ~3,000 genes. Purely oscillatory flow (zero mean shear) enhanced the expression of several growth factors and adhesion molecules (E-selectin, VCAM, MCP-1, IL-8, c-jun), relative to non-reversing flow (15 dyn/cm2 mean shear). The 2 Hz upregulation of certain atherogenic molecules such as VCAM, c-jun, and IL-8 was enhanced as the mean shear was reduced. Thus, the inflammatory response evoked at certain frequencies appears to be exacerbated by low, oscillatory shear. Keywords: Shear stress response
2006-02-22 | GSE4281 | GEO
Project description:This study characterizes the response of primary human endothelial cells (human umbilical vein endothelial cells, HUVECs) to the relative shear stress changes that occur during the initiation of arteriogenesis at the entrance regions to a collateral artery network. HUVECs were preconditioned to a baseline level of unidirectional shear of 15 dynes/cm2 for 24 hours. After 24 hours preconditioning, HUVECs were subjected to an arteriogenic stimulus that mimics the shear stress changes observed in the opposing entrance regions into a collateral artery network. The arteriogenic stimulus consisted of a 100% step wise increase in shear stress magnitude to a unidirectional 30 dynes/cm2 in either the same or opposite direction of the preconditioned shear stress. This simulates either the feeding entrance to the collateral artery circuit or the region that drains into the vasculature downstream of an obstruction in a major artery, respectively. In vivo analysis of collateral growth in the mouse hindlimb showed enhanced outward remodeling in the re-entrant (direction reversing) region that reconnects to the downstream arterial tree, suggesting reversal of shear stress direction as a key enhancer of arteriogenesis. Transcriptional profiling using microarray techniques identified that the reversal of shear stress direction, but not an increase in shear stress alone, yielded a broad-based enhancement of the mechanotransduction pathways necessary for the induction of arteriogenesis.
2016-04-01 | GSE46248 | GEO