scholarly journals Laminar Shear Stress Protects Against Premature Endothelial Senescence by SIRT1-Dependent Mechanisms

2021 ◽  
Vol 30 (2) ◽  
pp. 213-220
Author(s):  
Ji-Seok Kim ◽  
Jacqueline Sayoc ◽  
Kyung-Wan Baek ◽  
Joon-Young Park
Keyword(s):  
Shear Stress ◽  
Cellular Senescence ◽  
Wheel Running ◽  
High Flow ◽  
Premature Senescence ◽  
Protective Effects ◽  
Laminar Shear Stress ◽  
Protein Markers ◽  
Laminar Shear

PURPOSE:Accumulation of senescent endothelial cells (ECs) and development of vascular aging have been implicated in the etiology of vascular dysfunction and disease. Aerobic exercise has been recognized as the single most effective non-pharmacological anti-aging intervention via increased laminar shear stress (LSS). This study aimed to determine the protective effects of LSS against premature senescence and the underlying mechanism.METHODS: Carotid artery partial ligation surgery was performed on the left carotid arteries (LCAs) of C57BL/6J male mice to determine the effect of disturbed flow on the development of endothelial senescence. Senescence-associated β-galactosidase (SA-β-gal) staining was performed to measure cellular senescence. Expression levels of protein markers for cell senescence including p21, p16, and p53 were measured by western blotting.RESULTS: <i>En face</i> SA-β-gal staining was identified only in the partially ligated LCAs of voluntary wheel-running mice, suggesting a direct relevance of LSS on the prevention of vascular senescence. In the <i>in vitro</i> H<sub>2</sub>O<sub>2</sub>-induced premature senescence model, preconditioning of high-flow LSS (20 dyne/cm<sup>2</sup>, 36 hours) induced significant reduction in the percentage of SA-β-gal positive ECs. Expression of the molecular markers of cellular senescence such as p21, p16, and p53 was significantly decreased by LSS pretreatment. However, the protective effects of LSS against premature senescence were completely abolished by SIRT1 inhibition.CONCLUSIONS: The results suggest that high-flow LSS has protective effects against oxidative stress-induced premature endothelial senescence through a SIRT1-dependent mechanism.

Endothelial albumin permeability is shear dependent, time dependent, and reversible

1991 ◽  
Vol 260 (6) ◽  
pp. H1992-H1996 ◽  
Author(s):  
H. Jo ◽  
R. O. Dull ◽  
T. M. Hollis ◽  
J. M. Tarbell
Keyword(s):  
Shear Stress ◽  
Endothelial Cell ◽  
Fluorescein Isothiocyanate ◽  
Vascular Wall ◽  
Laminar Shear Stress ◽  
Aortic Endothelial Cells ◽  
Transendothelial Permeability ◽  
Steady Laminar Shear Stress ◽  
Laminar Shear

Altered permeability of vascular endothelium to macromolecules may play a role in vascular disease as well as vascular homeostasis. Because the shear stress of flowing blood on the vascular wall is known to influence many endothelial cell properties, an in vitro system to measure transendothelial permeability (Pe) to fluorescein isothiocyanate conjugated bovine serum albumin under defined physiological levels of steady laminar shear stress was developed. Bovine aortic endothelial cells grown on polycarbonate filters pretreated with gelatin and fibronectin constituted the model system. Onset of 1 dyn/cm2 shear stress resulted in a Pe rise from 5.1 +/- 1.3 x 10(-6) cm/s to 21.9 +/- 4.6 X 10(-6) cm/s at 60 min (n = 6); while 10 dyn/cm2 shear stress increased Pe from 4.8 +/- 1.5 X 10(-6) cm/s to 50.2 +/- 6.8 X 10(-6) cm/s at 30 min and 49.6 +/- 8.9 X 10(-6) cm/s at 60 (n = 9). Pe returned to preshear values within 120 and 60 min after removal of 1 and 10 dyn/cm2 shear stress, respectively. The data show that endothelial cell Pe in vitro is acutely sensitive to shear stress.

Abstract 13: Suppression of Atherosclerosis by CD39

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Yogendra Kanthi ◽  
Matthew Hyman ◽  
Hui Liao ◽  
Amy Baek ◽  
Scott Visovatti ◽  
...  
Keyword(s):  
Shear Stress ◽  
Platelet Activation ◽  
Receptor Expression ◽  
Plaque Burden ◽  
Laminar Shear Stress ◽  
Shear Forces ◽  
Lipoprotein Uptake ◽  
Laminar Shear ◽  
Deficient Mice

Atherosclerotic plaque rupture and thrombosis remains the leading cause of death in the United States. We investigated the role of CD39, a potent ecto-enzymatic regulator of platelet activation and leukocyte trafficking, in atherosclerosis. We generated mice deficient in CD39 on a hyperlipidemic, apoE -/- background and noted a two-fold higher plaque burden in when compared to apoE -/- controls ( P =0.003). We noted higher levels of circulating markers of platelet activation, soluble P-selectin (39%) and RANTES (60%), in the CD39-deficient mice ( P =0.003 and P =0.015, respectively, n=7-11). CD39-haploinsufficient mice had 1.8-fold greater enhanced platelet reactivity in response to ADP compared to controls ( P =0.03, n=3-8). Macrophages from CD39-deficient mice had significantly higher lipoprotein uptake in vitro . Correspondingly, CD39 overexpression in RAW cells inhibited scavenger receptor expression and lipoprotein uptake. Altered fluid mechanics contribute to atherosclerosis, with non-laminar shear stress enhancing regional plaque formation as seen in arterial bifurcations. We examined coronal sections of aortas from apoE −/− mice and observed that CD39 is poorly expressed in the endothelium in regions of turbulent blood flow, where plaque develops, supporting our hypothesis that endothelial CD39 can be induced by fluid phase shear forces. HUVEC treated with physiologic laminar shear stress (LS) (15 dynes/cm 2 ) had a 5.9-fold increase in CD39 protein ( P =0.004, N=3-7) and a concordant increase in nucleotidase activity ( P =0.03 N=3) compared to static controls (SS). We identified Krüppel like factor 2 (KLF2) as an upstream candidate for transcriptional regulation of CD39 induction by fluid shear forces. Silencing KLF2 in vitro led to a 55% decrease in CD39 mRNA induction with LS vs SS controls ( P =0.002, N=3-4). Chromatin immunoprecipitation revealed that KLF2 binds to the CD39 ( P =0.01, N=3) and this binding was further enhanced under laminar shear stress ( P =0.0007, N=3). These data show that CD39, an anti-thrombotic, anti-inflammatory enzyme is a critical regulator of atherosclerosis by modulating platelet, macrophage and endothelial function and mechanistically identify KLF2 as a direct, upstream regulator of CD39 expression.

Abstract 442: Flow-Dependent Regulation of Angiopoietin-2

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Winfried Goettsch ◽  
Corina Gryczka ◽  
Thomas Korff ◽  
Evelyn Ernst ◽  
Claudia Goettsch ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Transcription Factor ◽  
High Flow ◽  
Low Flow ◽  
Laminar Shear Stress ◽  
Forkhead Box ◽  
Angiopoietin 2 ◽  
Laminar Shear

Background: Endothelial cells are constantly exposed to high or low shear stress in arteries and veins by the flowing blood. Angiopoietin-2 (Ang-2) is acting as a critical regulator of vessel maturation and endothelial cell quiescence. In this study, we determined the effect of low and high laminar shear stress on the expression and release of angiopoietin (Ang-)2 in human endothelial cells, studied the role of nitric oxide and protein kinases in this context, determined the impact of VEGF on Ang-2, studied the expression, activity and translocation of the forkhead box O transcription factor FOXO1 by low and high shear stress, and analyzed the vessel- and flow-dependent expression of Ang-2 in vivo . Methods and Results: Primary cultures of human umbilical vein endothelial cells (HUVEC) were subjected to laminar shear stress at different physiological levels of laminar shear stress of 1, 5, 10, 15, and 30 dyne/cm 2 in a cone-and-plate viscometer. Ang-2 mRNA, protein expression and release was upregulated by 24 h of low (1 dyne/cm 2 ), but downregulated by high flow (30 dyne/cm 2 ) in human endothelial cells. Increased endothelial NO synthase expression and NO formation was not affecting regulation of Ang-2 by low or high flow. Tie2 protein expression, but not Tie2 phosphorylation was induced by high flow. Furthermore, low and high flow increased VEGF-A expression. Inhibition of VEGFR-2 prevented upregulation of Ang-2 by low flow, but not downregulation of Ang-2 by high flow. Upregulation of Ang-2 by VEGF was reduced by application of high flow. Forkhead box O (FOXO) transcription factor FOXO1 has been shown to regulate Ang-2 expression in endothelial cells. FOXO1 binding activity was reduced by high flow. Nuclear localization of transcription factor FOXO1 was not changed by low flow, but reduced by high flow. In vivo , Ang-2 was higher expressed in veins compared to arteries. Arterial ligation augmented Ang-2 expression in distal arterial low flow areas. Conclusion: Our results support a VEGF-dependent induction of Ang-2 in low flow areas, and FOXO1-dependent downregulation of Ang-2 in high flow areas. These data suggest a new mechanism of flow-dependent regulation of vessel stability and differentiation.

scholarly journals Resveratrol promotes endothelial cell wound healing under laminar shear stress through an estrogen receptor-α-dependent pathway

2014 ◽  
Vol 306 (6) ◽  
pp. H797-H806 ◽  
Author(s):  
Arif Yurdagul ◽  
James J. Kleinedler ◽  
Marshall C. McInnis ◽  
Alok R. Khandelwal ◽  
Allyson L. Spence ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Wound Healing ◽  
Shear Stress ◽  
Estrogen Receptor ◽  
Endothelial Cell ◽  
Endothelial Cell Proliferation ◽  
Laminar Shear Stress ◽  
Endothelial Cell Growth ◽  
Laminar Shear

Restenosis is an adverse outcome of angioplasty, characterized by vascular smooth muscle cell (VSMC) hyperplasia. However, therapies targeting VSMC proliferation delay reendothelialization, increasing the risk of thrombosis. Resveratrol (RESV) inhibits restenosis and promotes reendothelialization after arterial injury, but in vitro studies assessing RESV-mediated effects on endothelial cell growth contradict these findings. We thus hypothesized that fluid shear stress, mimicking physiological blood flow, would recapitulate RESV-dependent endothelial cell wound healing. Since RESV is an estrogen receptor (ER) agonist, we tested whether RESV promotes reendothelialization through an ER-α-dependent mechanism. Mice fed a high-fat diet or a diet supplemented with RESV were subjected to carotid artery injury. At 7 days after injury, RESV significantly accelerated reendothelialization compared with vehicle. In vitro wound healing assays demonstrated that RESV exhibits cell-type selectivity, inhibiting VSMC, but not endothelial cell growth. Under laminar shear stress (LSS), RESV dramatically enhanced endothelial cell wound healing and increased both the activation of extracellular signal-regulated kinase (ERK) and endothelial cell proliferation. Under LSS, small interfering RNA against ER-α, but not endothelial nitric oxide synthase, abolished RESV-induced ERK activation, endothelial cell proliferation, and wound healing. Thus these studies suggest that the EC phenotype induced by LSS better models the prohealing effects of RESV and that RESV and LSS interact to promote an ER-α-dependent mitogenic effect in endothelial cells.

scholarly journals Shear Stress Regulation of Endothelial Glycocalyx Structure Is Determined by Glucobiosynthesis

2020 ◽  
Vol 40 (2) ◽  
pp. 350-364 ◽  
Author(s):  
Gangqi Wang ◽  
Sarantos Kostidis ◽  
Gesa L. Tiemeier ◽  
Wendy M.P.J. Sol ◽  
Margreet R. de Vries ◽  
...  
Keyword(s):  
Shear Stress ◽  
Glucuronic Acid ◽  
Functional Adaptation ◽  
Endothelial Glycocalyx ◽  
Nuclear Magnetic Resonance Analysis ◽  
Laminar Shear Stress ◽  
Major Structural Component ◽  
Laminar Shear

Objective: Endothelial cells exposed to laminar shear stress express a thick glycocalyx on their surface that plays an important role in reducing vascular permeability and endothelial anti-inflammatory, antithrombotic, and antiangiogenic properties. Production and maintenance of this glycocalyx layer is dependent on cellular carbohydrate synthesis, but its regulation is still unknown. Approach and Results: Here, we show that biosynthesis of the major structural component of the endothelial glycocalyx, hyaluronan, is regulated by shear. Both in vitro as well as in in vivo, hyaluronan expression on the endothelial surface is increased on laminar shear and reduced when exposed to oscillatory flow, which is regulated by KLF2 (Krüppel-like Factor 2). Using a CRISPR-CAS9 edited small tetracysteine tag to endogenous HAS2 (hyaluronan synthase 2), we demonstrated increased translocation of HAS2 to the endothelial cell membrane during laminar shear. Hyaluronan production by HAS2 was shown to be further driven by availability of the hyaluronan substrates UDP-glucosamine and UDP-glucuronic acid. KLF2 inhibits endothelial glycolysis and allows for glucose intermediates to shuttle into the hexosamine- and glucuronic acid biosynthesis pathways, as measured using nuclear magnetic resonance analysis in combination with 13 C-labeled glucose. Conclusions: These data demonstrate how endothelial glycocalyx function and functional adaptation to shear is coupled to KLF2-mediated regulation of endothelial glycolysis.

scholarly journals miR-126 Is Involved in Vascular Remodeling under Laminar Shear Stress

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Ana Mondadori dos Santos ◽  
Laurent Metzinger ◽  
Oualid Haddad ◽  
Eléonore M’baya-Moutoula ◽  
Fatiha Taïbi ◽  
...  
Keyword(s):  
Shear Stress ◽  
Cell Phenotype ◽  
Laminar Shear Stress ◽  
Apo E ◽  
Micro Rnas ◽  
Significant Difference ◽  
High Level ◽  
Laminar Shear

Morphology and changes in gene expression of vascular endothelium are mainly due to shear stress and inflammation. Cell phenotype modulation has been clearly demonstrated to be controlled by small noncoding micro-RNAs (miRNAs). This study focused on the effect of laminar shear stress (LSS) on human endothelial cells (HUVECs), with an emphasis on the role of miRNA-126 (miR-126). Exposure of HUVECsin vitroto LSS modified the shape of HUVECs and concomitantly regulated the expression of miR-126, vascular cell adhesion molecule 1 (VCAM-1), and syndecan-4 (SDC-4). A significant upregulation of miR-126 during long-term exposure to flow was shown. Interestingly, LSS enhanced SDC-4 expression on the HUVEC membranes. Overexpression of miR-126 in HUVECs decreased the levels of targets stromal cell-derived factor-1 SDF-1/CXCL12 and VCAM-1 but increased the expression of RGS16, CXCR4, and SDC-4. No significant difference in terms of cell proliferation and apoptosis was observed between scramble, anti-miR-126, and pre-miR-126 transfected HUVECs. In Apo-E KO/CKD mice aortas expressing a high level of miR-126, SDC-4 was concomitantly increased. In conclusion, our results suggest that miR-126 (i) is overexpressed by long-term LSS, (ii) has a role in up- and downregulation of genes involved in atherosclerosis, and (iii) affects SDC-4 expression.

Abstract 15187: Shear Stress-regulated Mir-27b Controls Pericyte Recruitment in vitro and in vivo and Contributes to Vessel Maturation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Shemsi Demolli ◽  
Anuradha Doddaballapur ◽  
Konstantin Stark ◽  
Reinier A Boon ◽  
Ankathrin Eckart ◽  
...  
Keyword(s):  
Shear Stress ◽  
Endothelial Cell ◽  
Barrier Function ◽  
Molecular Mechanisms ◽  
Laminar Shear Stress ◽  
Pericyte Coverage ◽  
Vessel Maturation ◽  
Laminar Shear

Vessel maturation involves recruitment of mural cells. Laminar shear stress is a major trigger for vessel maturation. However, the molecular mechanisms by which shear stress affects recruitment of pericytes are unclear. MicroRNAs are small non-coding RNAs, which post-transcriptionally control gene expression. Since shear stress regulates various miRs, we hypothesize that flow-induced miRs inhibit repulsive cues and facilitate mural cell coverage. Laminar shear stress for 72h induces the up-regulation of miR-27b (2.8±0.24-fold vs static, p<0.05) in cultured endothelial cells (ECs) and in mouse femoral artery segments that were exposed to physiological shear stress ex vivo (1.5±0.14-fold vs no flow, p<0.05). Predicted targets for miR-27b include members of the semaphorin (SEMA) family (known to regulate repulsive signaling) and angiopoietin-2 (Ang2), which causes vessel destabilization. MiR-27b overexpression reduces SEMA6A (63.5±13.5%), SEMA6D (58±26%), and Ang2 (51.5±11%) expression. To determine whether miR-27b controls pericyte recruitment, we tested the effect of endothelial miR-27b on adhesion of pericytes. Overexpression of miR-27b increased the adhesion of pericytes (p<0.05) and inhibition of miR-27b reduced pericyte adhesion in vitro (p<0.05). In an in vitro matrigel assay, overexpression of miR-27b increased pericyte coverage of endothelial cell tubes (155±45%, p<0.05), whereas inhibition of miR-27b reduced pericyte coverage (81±15%). In addition, overexpression of miR-27b in vitro increases barrier function (p<0.05) in endothelial cell-pericyte co-culture assays whereas inhibition of miR-27b decreases barrier function (p<0.05). Silencing of SEMA6A and SEMA6D rescued the reduced pericyte adhesion that is caused by miR-27 inhibition (p<0.05). Furthermore, inhibition of SEMA6D increases barrier function. In vivo inhibition of miR-27a/b significantly increased edema (p<0.05) in the uterus which was associated with a significantly reduced pericyte coverage of the vessels (p<0.05). Taken together, our data demonstrate that shear stress regulate miR-27b, which targets Ang2 and semaphorins, thereby controlling pericyte adhesion and coverage in vitro and in vivo.

Epigenetic histones modification and cardiovascular lineage programming in mouse embryonic stem cells exposed to laminar shear stress

2006 ◽  
Vol 45 (3) ◽  
pp. e56
Author(s):  
Barbara Illi ◽  
Alessandro Scopece ◽  
Simona Nanni ◽  
Antonella Farsetti ◽  
Liliana Morgante ◽  
...  
Keyword(s):  
Stem Cells ◽  
Shear Stress ◽  
Embryonic Stem Cells ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells ◽  
Laminar Shear Stress ◽  
Laminar Shear
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