Abstract 5440: Klf2 Inhibits Hif-1α Expression and Function in the Endothelium

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Daiji Kawanami ◽  
Zhiyong Lin ◽  
Ganapati Mahabaleshwar ◽  
G. B Atkins ◽  
Anne Hamik ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Proteasome Inhibitors ◽  
Cell Types ◽  
Tube Formation ◽  
Protein Levels ◽  
Umbilical Vein Endothelial Cells ◽  
And Function ◽  
Mediated Reduction

Introduction: Hypoxia-inducible factor 1 (HIF-1) is a central regulator of the hypoxic response in many cell types. In endothelial cells, HIF-1 induces the expression of key pro-angiogenic factors such as vascular endothelial growth factor (VEGF) to induce new blood vessel formation. Recent studies have identified Kruppel-like Factor 2 (KLF2) as a potent inhibitor of angiogenesis. However, the role of KLF2 in regulating the expression and function of HIF-1 has not been evaluated. Hypothesis: KLF2 inhibits HIF-1α expression and function. Methods and Results: Adenoviral overexpression of KLF2 in human umbilical vein endothelial cells (HUVECs) inhibited hypoxia-induced expression of HIF-1α, VEGF secretion, and matrigel tube formation. Conversely, siRNA-mediated knockdown of KLF2 in HUVECs increased HIF-1α expression and VEGF secretion. Consistent with this observation, KLF2−/− mouse embryonic fibroblasts (MEFs) showed accelerated HIF-1α accumulation in response to hypoxia and a marked induction of VEGF secretion (90.4±7.4 pg/ml in KLF2+/+ versus 234.6±6.1 pg/ml in KLF2−/−, p<0.01). From a mechanistic standpoint, KLF2-mediated reduction of HIF-1α level was attenuated by three distinct proteasome inhibitors (MG132, ALLN, or lactacystin), demonstrating that KLF2 mediated reduction of HIF-1α protein was proteasome-dependent. In addition, KLF2 maintained its ability to inhibit HIF-1α protein levels in VHL−/− cells, thermo-sensitive E1 deficient cells, and p53−/− cells. Finally, co-immunoprecipitation experiments revealed that KLF2 overexpression disrupted the interaction between HIF-1α and its chaperone Hsp90, suggesting that KLF2 promotes degradation of HIF-1α by affecting its folding and maturation. Conclusions: These observations identify KLF2 as a novel inhibitor of HIF-1α expression and function through a VHL/p53 independent but proteasome dependent pathway. As such, KLF2 may be a target for modulating the angiogenic response in disease states.

scholarly journals Characterization of Heparin Affin Regulatory Peptide Signaling in Human Endothelial Cells

2005 ◽  
Vol 280 (23) ◽  
pp. 22454-22461 ◽  
Author(s):  
Apostolos Polykratis ◽  
Panagiotis Katsoris ◽  
José Courty ◽  
Evangelia Papadimitriou
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Tyrosine Phosphatase ◽  
Neuronal Cell ◽  
Cell Types ◽  
Tube Formation ◽  
Regulatory Peptide ◽  
Intracellular Signals ◽  
Umbilical Vein Endothelial Cells ◽  
Interfering Rna

Heparin affin regulatory peptide (HARP) is an 18-kDa secreted growth factor that has a high affinity for heparin and a potent role on tumor growth and angiogenesis. We have previously reported that HARP is mitogenic for different types of endothelial cells and also affects cell migration and differentiation (12). In this study we examined the signaling pathways involved in the migration and tube formation on matrigel of human umbilical vein endothelial cells (HUVEC) induced by HARP. We report for the first time that receptor-type protein-tyrosine phosphatase β/ζ (RPTPβ/ζ), which is a receptor for HARP in neuronal cell types, is also expressed in HUVEC. We also document that HARP signaling through RPTPβ/ζ leads to activation of Src kinase, focal adhesion kinase, phosphatidylinositol 3-kinase, and Erk1/2. Sodium orthovanadate, chondroitin sulfate-C, PP1, wortmannin, LY294002, and U0126 inhibit HARP-mediated signaling and HUVEC migration and tube formation. In addition, RPTPβ/ζ suppression using small interfering RNA technology interrupts intracellular signals and HUVEC migration and tube formation induced by HARP. These results establish the role of RPTPβ/ζ as a receptor of HARP in HUVEC and elucidate the HARP signaling pathway in endothelial cells.

scholarly journals Mir526b and Mir655 Promote Tumour Associated Angiogenesis and Lymphangiogenesis in Breast Cancer

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 938 ◽  
Author(s):  
Stephanie Hunter ◽  
Braydon Nault ◽  
Kingsley Chukwunonso Ugwuagbo ◽  
Sujit Maiti ◽  
Mousumi Majumder
Keyword(s):  
Breast Cancer ◽  
Endothelial Cells ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Breast Tumour ◽  
Tube Formation ◽  
Akt Pathway ◽  
Akt Inhibitor ◽  
Cox 2 ◽  
Umbilical Vein Endothelial Cells

MicroRNAs (miRNAs) are small endogenously produced RNAs, which regulate growth and development, and oncogenic miRNA regulate tumor growth and metastasis. Tumour-associated angiogenesis and lymphangiogenesis are processes involving the release of growth factors from tumour cells into the microenvioronemnt to communicate with endothelial cells to induce vascular propagation. Here, we examined the roles of cyclo-oxygenase (COX)-2 induced miR526b and miR655 in tumour-associated angiogenesis and lymphangiogenesis. Ectopic overexpression of miR526b and miR655 in poorly metastatic estrogen receptor (ER) positive MCF7 breast cancer cells resulted in upregulation of angiogenesis and lymphangiogenesis markers vascular endothelial growth factor A (VEGFA); VEGFC; VEGFD; COX-2; lymphatic vessel endothelial hyaluronan receptor-1 (LYVE1); and receptors VEGFR1, VEGFR2, and EP4. Further, miRNA-high cell free conditioned media promoted migration and tube formation by human umbilical vein endothelial cells (HUVECs), and upregulated VEGFR1, VEGFR2, and EP4 expression, showing paracrine stimulation of miRNA in the tumor microenvironment. The miRNA-induced migration and tube formation phenotypes were abrogated with EP4 antagonist or PI3K/Akt inhibitor treatments, confirming the involvement of the EP4 and PI3K/Akt pathway. Tumour supressor gene PTEN was found to be downregulated in miRNA high cells, confirming that it is a target of both miRNAs. PTEN inhibits hypoxia-inducible factor-1 (HIF1α) and the PI3K/Akt pathway, and loss of regulation of these pathways through PTEN results in upregulation of VEGF expression. Moreover, in breast tumors, angiogenesis marker VEGFA and lymphangiogenesis marker VEGFD expression was found to be significantly higher compared with non-adjacent control, and expression of miR526b and miR655 was positively correlated with VEGFA, VEGFC, VEGFD, CD31, and LYVE1 expression in breast tumour samples. These findings further strengthen the role of miRNAs as breast cancer biomarkers and EP4 as a potential therapeutic target to abrogate miRNA-induced angiogenesis and lymphangiogenesis in breast cancer.

Assembly and Activation of the Intrinsic Fibrinolytic Pathway on the Surface of Human Endothelial Cells in Culture

1995 ◽  
Vol 74 (02) ◽  
pp. 698-703 ◽  
Author(s):  
Catherine Lenich ◽  
Ralph Pannell ◽  
Victor Gurewich
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Factor Xii ◽  
Plasminogen Activation ◽  
High Molecular Weight Kininogen ◽  
Human Endothelial Cells ◽  
Intrinsic Pathway ◽  
Local Fibrinolysis ◽  
Umbilical Vein Endothelial Cells ◽  
And Function

SummaryFactor XII has long been implicated in the intrinsic pathway of fibrinolysis, but the mechanism by which it triggers plasminogen activation and targets fibrinolysis has not been established. In the present study, the assembly and function of activated Factor XII (F.XIIa), prourokinase (pro-u-PA), high molecular weight kininogen (H-kininogen), and prekallikrein on human umbilical vein endothelial cells (HUVEC) was investigated. 125I-prekallikrein was shown to bind to HUVEC via receptor-bound H-kininogen in the presence of 50 μM ZnCl2. After the addition of F.XIIa, 78% of the 125I-prekallikrein initially bound to HUVEC was converted to 125I-kallikrein. However, only 6% of the HUVEC-bound 125I-pro-u-PA was thereby activated. This discrepancy was shown to be related to rapid dissociation (>50% within 15 min) of prekallikrein/kallikrein, but not pro-u-PA, from HUVEC. Increasing the level of cell-bound kallikrein increased the portion of cell-bound pro-u-PA activated, indicating that their co-localization was important for this pathway. Finally, F.XIIa was shown to trigger plasminogen activation on HUVEC via this pathway. This assembly of reactants on the endothelium suggests a mechanism whereby local fibrinolysis may be triggered by blood coagulation.

INTERACTION OF S PROTEIN/VITRONECTIN WITH CULTURED ENDOTHELIAL CELLS: PROMOTION OF ATTACHMENT AND SPECIFIC BINDING

1987 ◽  
Author(s):  
K T Preissner ◽  
E Anders ◽  
G Müller-Berghaus
Keyword(s):  
Endothelial Cells ◽  
Cell Attachment ◽  
Specific Binding ◽  
Umbilical Vein ◽  
Attachment Site ◽  
Cell Types ◽  
S Protein ◽  
Specific Association ◽  
Umbilical Vein Endothelial Cells ◽  
Adhesive Proteins

The interaction of the complement inhibitor S protein, which is identical to the serum spreading factor, vitronectin, with cultured human endothelial cells of macro- and microvas- cular origin was investigated. Purified S protein, coated for 2 h on polystyrene petri dishes, induced concentration- and time-dependent attachment and spreading of human umbilical vein endothelial cells (HUVEC) as well as human omental tissqe microvasular endothelial cells (HOTMEC) at 37°C. With 3 × 105 cells/ml (final concentration) more than 50% of the cells attached within 2 h incubation at 0.3 - 3 μg/ml S protein. The effect of S protein was specific, since only monospecific antibodies against S protein prevented attachment of cells, while antibodies against fibronectin, fibrinogen or von Wille-brand factor were uneffective. The pentapeptide Gly-Arg-Gly-Asp-Ser, which contains the cell-attachment site of these adhesive proteins including S protein, inhibited the activity of S protein to promote attachment of endothelial cells in a concentration-dependent fashion; at 200 μM peptide, less than 10% of the cells became attached. Direct binding of S protein to HUVEC and HOTMEC was studied with cells in suspension at a concentration of 1 × 106 cells/ml in the presence of 1% (w/v) human serum albumin and 1 mM CaCl2 and was maximal after 120 min. Both cell types bound S protein in a concentration-dependent fashion with an estimated dissociation constant KD=0.2pM. More than 80% of bound radiolabelled S protein was displaced by unlabelled S protein, whereas binding was reduced to about 50% by the addition in excess of either fibronectin, fibrinogen, von Willebrand factor or the pentapeptide. These findings provide evidence for the specific association of S protein with endothelial cells, ultimately leading to attachment and spreading of cells. Although the promotion of attachment was highly specific for S protein, other adhesive proteins than S protein, also known to associate with endothelial cells, may in part compete with direct S protein binding.

Hypoxia-induced pulmonary endothelin-1 expression is unaltered by nitric oxide

2002 ◽  
Vol 92 (3) ◽  
pp. 1152-1158 ◽  
Author(s):  
Scott Earley ◽  
Leif D. Nelin ◽  
Louis G. Chicoine ◽  
Benjimen R. Walker
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Promoter Activity ◽  
Umbilical Vein ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Exposure ◽  
Mrna Levels ◽  
Protective Effects ◽  
No Donor ◽  
Umbilical Vein Endothelial Cells

Nitric oxide (NO) attenuates hypoxia-induced endothelin (ET)-1 expression in cultured umbilical vein endothelial cells. We hypothesized that NO similarly attenuates hypoxia-induced increases in ET-1 expression in the lungs of intact animals and reasoned that potentially reduced ET-1 levels may contribute to the protective effects of NO against the development of pulmonary hypertension during chronic hypoxia. As expected, hypoxic exposure (24 h, 10% O2) increased rat lung ET-1 peptide and prepro-ET-1 mRNA levels. Contrary to our hypothesis, inhaled NO (iNO) did not attenuate hypoxia-induced increases in pulmonary ET-1 peptide or prepro-ET-1 mRNA levels. Because of this surprising finding, we also examined the effects of NO on hypoxia-induced increases in ET peptide levels in cultured cell experiments. Consistent with the results of iNO experiments, administration of the NO donor S-nitroso- N-acetyl-penicillamine to cultured bovine pulmonary endothelial cells did not attenuate increases in ET peptide levels resulting from hypoxic (24 h, 3% O2) exposure. In additional experiments, we examined the effects of NO on the activity of a cloned ET-1 promoter fragment containing a functional hypoxia inducible factor-1 binding site in reporter gene experiments. Whereas moderate hypoxia (24 h, 3% O2) had no effect on ET-1 promoter activity, activity was increased by severe hypoxic (24 h, 0.5% O2) exposure. ET-1 promoter activity after S-nitroso- N-acetyl-penicillamine administration during severe hypoxia was greater than that in normoxic controls, although activity was reduced compared with that in hypoxic controls. These findings suggest that hypoxia-induced pulmonary ET-1 expression is unaffected by NO.

scholarly journals Anti-Inflammatory and Anti-Apoptotic Effects of Stybenpropol A on Human Umbilical Vein Endothelial Cells

2019 ◽  
Vol 20 (21) ◽  
pp. 5383 ◽  
Author(s):  
Li Zhang ◽  
Feifei Wang ◽  
Qing Zhang ◽  
Qiuming Liang ◽  
Shumei Wang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Adhesion ◽  
Adhesion Molecule ◽  
Cell Adhesion Molecule ◽  
Umbilical Vein ◽  
Caspase 9 ◽  
Protein Levels ◽  
Tnf Α ◽  
Umbilical Vein Endothelial Cells ◽  
Cell Adhesion Molecule 1

Inflammation is a key mediator in the progression of atherosclerosis (AS). Benzoinum, a resin secreted from the bark of Styrax tonkinensis, has been widely used as a form of traditional Chinese medicine in clinical settings to enhance cardiovascular function, but the active components of the resin responsible for those pharmaceutical effects remain unclear. To better clarify these components, a new phenylpropane derivative termed stybenpropol A was isolated from benzoinum and characterized via comprehensive spectra a nalysis. We further assessed how this phenylpropane derivative affected treatment of human umbilical vein endothelial cells (HUVECs) with tumor necrosis factor-α (TNF-α). Our results revealed that stybenpropol A reduced soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), interleukin-8 (IL-8), and interleukin-1β (IL-1β) expression by ELISA, inhibited apoptosis, and accelerated nitric oxide (NO) release in TNF-α-treated HUVECs. We further found that stybenpropol A decreased VCAM-1, ICAM-1, Bax, and caspase-9 protein levels, and increased the protein levels of Bcl-2, IKK-β, and IκB-α. This study identified a new, natural phenylpropane derivative of benzoinum, and is the first to reveal its cytoprotective effects in the context of TNF-α-treated HUVECs via regulation of the NF-κB and caspase-9 signaling pathways.

Proliferation and functionality of human umbilical vein endothelial cells on angiopoietin-1 immobilized 316L stainless steel

2015 ◽  
Vol 3 (44) ◽  
pp. 8717-8728 ◽  
Author(s):  
Xin Li ◽  
Shuheng Yuan ◽  
Si Chen ◽  
Rifang Luo ◽  
Kaiqin Xiong ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Endothelial Cells ◽  
316L Stainless Steel ◽  
Umbilical Vein ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells ◽  
And Function ◽  
Functionalized Surface ◽  
Angiopoietin 1

An angiopoietin-1 functionalized surface was establishedviapolydopamine coating and regulated HUVECs survival, proliferation and function.

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