Angiotensin II increases the release of endothelin-I from human cultured endothelial cells but does not regulate its circulating levels

1999 ◽  
Vol 96 (3) ◽  
pp. 261-270 ◽  
Author(s):  
Claudio FERRI ◽  
Giovambattista DESIDERI ◽  
Roberta BALDONCINI ◽  
Cesare BELLINI ◽  
Marco VALENTI ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Protein Synthesis ◽  
Angiotensin Ii ◽  
At1 Receptor ◽  
Dependent Manner ◽  
Synthesis Inhibitor ◽  
Endothelin 1 ◽  
Cultured Endothelial Cells

We investigated the effect of angiotensin II on endothelin-1 secretion in vitro and in vivo. In vivo, angiotensin II was given intravenously to 23 essential hypertensive and 8 control subjects according to different protocols: Study A, 1.0 ngċmin-1ċkg-1 and 3.0 ngċmin-1ċkg-1 angiotensin II for 30 min each; Study B, 1.0 ngċmin-1ċkg-1 and 3.0 ngċmin-1ċkg-1 angiotensin II for 120 min each; Study C, 3.0 ngċmin-1ċkg-1 angiotensin II for 30 min followed by a dose increment of 3.0 ngċmin-1ċkg-1 every 30 min until mean blood pressure levels increased by 25 mmHg; Study D, 1.0 ngċmin-1ċkg-1 followed by 3.0 ngċmin-1ċkg-1 angiotensin II for 60 min each on two different NaCl diets (either 20 mmol NaCl/day or 220 mmol NaCl/day, both for 1 week). In all in vivo studies neither plasma nor urine endothelin-1 levels changed with angiotensin II infusion. In contrast, angiotensin II (10-9, 10-8, 10-7 mol/l) stimulated endothelin-1 secretion from cultured human vascular endothelial cells derived from umbilical cord veins in a time- and dose-dependent manner. The in vitro angiotensin II effects were abolished by candesartan cilexetil, an inhibitor of the membrane-bound AT1 receptor, and also by actinomycin D, an RNA synthesis inhibitor, and cycloheximide, a protein synthesis inhibitor, indicating that endothelin-1 release depended on AT1 receptor subtype and de novo protein synthesis. Our findings indicate that angiotensin II regulates endothelin-1 release by cultured endothelial cells through an AT1 receptor-dependent pathway, but does not influence circulating endothelin-1 levels in vivo.

Shear Stress Modulates the Expression of Thrombospondin-1 and CD36 in Endothelial Cells in vitro and during Shear Stress-Induced Angiogenesis in vivo

2006 ◽  
Vol 19 (1) ◽  
pp. 205873920601900 ◽  
Author(s):  
M. Bongrazio ◽  
L. DA Silva-Azevedo ◽  
E.C. Bergmann ◽  
O. Baum ◽  
B. Hinz ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Western Blot ◽  
Dependent Manner ◽  
Vascular Networks ◽  
Thrombospondin 1 ◽  
Matrix Bound ◽  
Stress Dependent

Binding of thrombospondin-1 (TSP-1) to the CD36 receptor inhibits angiogenesis and induces apoptosis in endothelial cells (EC). Conversely, matrix-bound TSP-1 supports vessel formation. In this study we analyzed the shear stress-dependent expression of TSP-1 and CD36 in endothelial cells in vitro and in vivo to reveal its putative role in the blood flow-induced remodelling of vascular networks. Shear stress was applied to EC using a cone-and-plate apparatus and gene expression was analyzed by RT-PCR, Northern and Western blot. Angiogenesis in skeletal muscles of prazosin-fed (50 mg/1 drinking water; 4 d) mice was assessed by measuring capillary-to-fiber (C/F) ratios. Protein expression in whole muscle homogenates (WMH) or BS-1 lectin-enriched EC fractions (ECF) was analyzed by Western blot. Shear stress down-regulated TSP-1 and CD36 expression in vitro in a force- and time-dependent manner sustained for at least 72 h and reversible by restoration of no-flow conditions. In vivo, shear stress-driven increase of C/F in prazosin-fed mice was associated with reduced expression of TSP-1 and CD36 in ECF, while TSP-1 expression in WMH was increased. Down-regulation of endothelial TSP-1/CD36 by shear stress suggests a mechanism for inhibition of apoptosis in perfused vessels and pruning in the absence of flow. The increase of extra-endothelial (e.g. matrix-bound) TSP-1 could support a splitting type of vessel growth.

Abstract 5566: Recovery of Erk Signaling Restores Defective Angiogenesis and Arteriogenesis in Synectin-Deficient Animals

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Bin Ren ◽  
Arpita Mukhopadhyay* ◽  
Anthony A Lanahan ◽  
Zhen W Zhuang ◽  
Karen L Moodie ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Branching Morphogenesis ◽  
Erk Signaling ◽  
Dependent Manner ◽  
Wild Type ◽  
Erk Activation ◽  
Arterial Development ◽  
Constitutively Active

Background : Arterial morphogenesis is an important and poorly understood process. We have previously demonstrated that disruption of synectin gene expression in mice and zebrafish results in impaired arterial development and branching morphogenesis. Synectin null endothelial cells demonstrate reduced VEGF responsiveness in terms of migration, proliferation and differentiation and ERK-1/2 activation (Chittenden et al, Dev Cell 2006). Since ERK has been established as major participants in the regulation of cell growth and differentiation and Erk activation has been previously linked to arterial morphogenesis, we evaluated whether activation of Erk signaling in synectin disrupted mice and zebrafish as well as synectin KO arterial endothelial cells (ECs) would restore defective migration, arterial differentiation, angiogenesis and arteriogenesis. To stimulate ERK signaling we used partial inhibition of PI3-K activity to reduce Akt-dependent suppression of Raf1 activation or introduction of constitutively active ERK construct. Methods : In vitro studies were conducted with primary arterial ECs isolated from synectin wild type (WT) and knock out (KO) mice. In vivo studies were carried out in WT and synectin deficient mice and synectin knockdown zebrafish embryos. Results: Exposure of synectin −/− arterial EC to two selective PI3K inhibitors GS4898 or LY294002 in vitro restored ERK activation in a dose-dependent manner and returned cell migration and in vitro branching morphogenesis to wild type levels. Transduction of a constitutively active ERK construct in vitro or in a Matrigel model in vivo had similar effect. Systemic treatment of synectin −/− mice with GS4898 fully restored impaired angiogenesis and arterial morphogenesis in adult animals in the setting of hindlimb ischemia. Similar treatment nearly completely restored arterial development defects in zebrafish treated with a synectin morpholino. Conclusions: ERK activation plays a key role in arteriogenesis both in adult tissues and during embryonic development. Activation of compromised ERK-1/2 signaling may be a novel therapeutic intervention to stimulate arteriogenesis.

Accutin, a New Disintegrin, Inhibits Angiogenesis In Vitro and In Vivo by Acting as Integrin vβ3 Antagonist and Inducing Apoptosis

Blood ◽  
1998 ◽  
Vol 92 (9) ◽  
pp. 3268-3276 ◽  
Author(s):  
Chia Hsin Yeh ◽  
Hui-Chin Peng ◽  
Tur-Fu Huang
Keyword(s):  
Endothelial Cells ◽  
Umbilical Vein ◽  
Fluorescein Isothiocyanate ◽  
Adenosine Diphosphate ◽  
Tube Formation ◽  
Platelet Glycoprotein ◽  
Dependent Manner ◽  
Antiangiogenic Effect

Abstract Endothelial integrins play an essential role in angiogenesis and cell survival. Accutin, a new member of disintegrin family derived from venom of Agkistrodon acutus, potently inhibited human platelet aggregation caused by various agonists (eg, thrombin, collagen, and, adenosine diphosphate [ADP]) through the blockade of fibrinogen binding to platelet glycoprotein IIb/IIIa (ie, integrin IIbβ3). In this report, we describe that accutin specifically inhibited the binding of monoclonal antibody (MoAb) 7E3, which recognizes integrin vβ3, to human umbilical vein endothelial cells (HUVECs), but not those of other anti-integrin MoAbs such as 2β1, 3β1, and 5β1. Moreover, accutin, but not the control peptide GRGES, dose-dependently inhibited the 7E3 interaction with HUVECs. Both 7E3 and GRGDS, but not GRGES or Integrelin, significantly blocked fluorescein isothiocyanate-conjugated accutin binding to HUVEC. In functional studies, accutin exhibited inhibitory effects on HUVEC adhesion to immobilized fibrinogen, fibronectin and vitronectin, and the capillary-like tube formation on Matrigel in a dose- and RGD-dependent manner. In addition, it exhibited an effective antiangiogenic effect in vivo when assayed by using the 10-day-old embryo chick CAM model. Furthermore, it potently induced HUVEC apoptotic DNA fragmentation as examined by electrophoretic and flow cytometric assays. In conclusion, accutin inhibits angiogenesis in vivo and in vitro by blocking integrin vβ3 of endothelial cells and by inducing apoptosis. The antiangiogenic activity of disintegrins might be explored as the target of developing the potential antimetastatic agents. © 1998 by The American Society of Hematology.

Hydrocortisone abolishes the angiotensin II-mediated potentiation of endothelin-I in bovine bronchi

2000 ◽  
Vol 100 (1) ◽  
pp. 19-23
Author(s):  
A. J. BROWN ◽  
J. E. NALLY
Keyword(s):  
Angiotensin Ii ◽  
Species Differences ◽  
Inhaled Corticosteroids ◽  
Response Curves ◽  
Endothelin 1 ◽  
Asthmatic Patients ◽  
Presence And Absence ◽  
Evoked Contractions

Angiotensin II potentiates methacholine-evoked bronchoconstriction both in bovine airways in vitro and in asthmatic patients in vivo. Angiotensin II also potentiates endothelin-1-evoked contractions in vitro, but fails to alter such contractions in vivo. One possible confounding factor in patients is their use of inhaled corticosteroids. Accordingly the present study examined the effects of hydrocortisone (cortisol) on contractions evoked by methacholine and endothelin-1 in the presence and absence of angiotensin II. Contractions of rings of isolated bovine airways were measured isometrically in organ baths. Concentration–response curves were obtained for endothelin-1 or methacholine in the presence and absence of angiotensin II, hydrocortisone and a combination of angiotensin II and hydrocortisone. Hydrocortisone abolished the angiotensin II-mediated potentiation of endothelin-1-evoked, but not methacholine-evoked, contractions. Hydrocortisone alone evoked the enhancement of methacholine responses, similar to the effect produced by angiotensin II. While species differences may exist, our present results suggest that the use of corticosteroids can have a profound effect on the interaction between angiotensin II and endothelin-1. Accordingly, the presence of inhaled corticosteroids might explain the differences between the results obtained in vitro and in vivo.

scholarly journals PPARγ regulates adipose triglyceride lipase in adipocytes in vitro and in vivo

2007 ◽  
Vol 293 (6) ◽  
pp. E1736-E1745 ◽  
Author(s):  
Erin E. Kershaw ◽  
Michael Schupp ◽  
Hong-Ping Guan ◽  
Noah P. Gardner ◽  
Mitchell A. Lazar ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Adipose Tissue ◽  
Lipid Metabolism ◽  
Protein Synthesis Inhibitor ◽  
Adipose Triglyceride Lipase ◽  
Dependent Manner ◽  
Triglyceride Lipase ◽  
Brown Adipose

Peroxisome proliferator-activated receptor-γ (PPARγ) regulates adipocyte genes involved in adipogenesis and lipid metabolism and is the molecular target for thiazolidinedione (TZD) antidiabetic agents. Adipose triglyceride lipase (ATGL) is a recently described triglyceride-specific lipase that is induced during adipogenesis and remains highly expressed in mature adipocytes. This study evaluates the ability of PPARγ to directly regulate ATGL expression in adipocytes in vitro and in vivo. In fully differentiated 3T3-L1 adipocytes, ATGL mRNA and protein are increased by TZD and non-TZD PPARγ agonists in a dose- and time-dependent manner. Rosiglitazone-mediated induction of ATGL mRNA is rapid and is not inhibited by the protein synthesis inhibitor cycloheximide, indicating that intervening protein synthesis is not required for this effect. Rosiglitazone-mediated induction of ATGL mRNA and protein is inhibited by the PPARγ-specific antagonist GW-9662 and is also significantly reduced following siRNA-mediated knockdown of PPARγ, supporting the direct transcriptional regulation of ATGL by PPARγ. In vivo, ATGL mRNA and protein are increased by rosiglitazone treatment in white and brown adipose tissue of mice with and without obesity due to high-fat diet or leptin deficiency. Thus, PPARγ positively regulates ATGL mRNA and protein expression in mature adipocytes in vitro and in adipose tissue in vivo, suggesting a role for ATGL in mediating PPARγ's effects on lipid metabolism.

The mechanism of low molecular weight heparin (LMWH) inhibition of tumor growth

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 13093-13093 ◽  
Author(s):  
S. L. Smiley ◽  
D. O. Henry ◽  
M. K. Wong
Keyword(s):  
Endothelial Cells ◽  
Tumor Growth ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Receptor System ◽  
Fgf Receptor ◽  
Tumor Inhibition ◽  
Inhibition Of Tumor Growth

13093 Background: Clinical studies show that LMWHs improve survival in cancer patients. There is compelling and mounting evidence that non-anticoagulation factors are at play, and that these may be contributing in a major way to improved patient outcome. Methods and Results: Dalteparin, enoxaparin, and tinzaparin were tested for their in vivo ability to inhibit tumor lines engineered for aggressive angiogenesis-driven growth. Therapeutic daily doses of drug administered the day following tumor inoculation resulted in significant angiogenesis and tumor inhibition. We previously showed that LMWHs inhibit fibroblast growth factor (FGF) -induced mitogenesis of Tumor Derived Endothelial Cells (TDECs) in a time and concentration dependent manner in vitro. We now show that this endothelial inhibition occurs through LMWHs-mediated reduction of phosphorylation and down stream signaling through ERK. The potency of LMWH was significantly reduced when TDECs were pretreated with heparinase- suggesting that the molecular target for LMWH may be the cell surface, low affinity FGF receptor system. Both our in vivo and in vitro studies demonstrate that angiogenesis and tumor inhibition are greatest for dalteparin > tinzaparin > enoxaparin. Clues to the heparin-TDECs interaction comes from tracking the real-time movement of FGF using a highly fluorescent nanocrystal bead decorated on its surface with FGF. High resolution video-microscopy shows FGF binding onto TDEC surfaces, but once heparin enters the environment, FGF detaches from the TDECs and migrates to the heparin. This ultimately results in significant TDEC growth inhibition as compared to controls. Conclusion: LMWH treatment at pharmacologic doses significantly blunts tumor growth and angiogenesis. This inhibition resides in part via heparin’s ability to sequester FGF from the low affinity receptor system on tumor endothelial cells. No significant financial relationships to disclose.

scholarly journals Endogenous Ceramide Contributes to the Transcytosis of oxLDL across Endothelial Cells and Promotes Its Subendothelial Retention in Vascular Wall

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Wenjing Li ◽  
Xiaoyan Yang ◽  
Shasha Xing ◽  
Fang Bian ◽  
Wanjing Yao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Vascular Endothelial Cells ◽  
Atherosclerotic Lesion ◽  
Vascular Wall ◽  
Acid Sphingomyelinase ◽  
Synthesis Inhibitor ◽  
Ceramide Production

Oxidized low density of lipoprotein (oxLDL) is the major lipid found in atherosclerotic lesion and elevated plasma oxLDL is recognized to be a risk factor of atherosclerosis. Whether plasma oxLDL could be transported across endothelial cells and initiate atherosclerotic changes remains unknown. In an establishedin vitrocellular transcytosis model, the present study found that oxLDL could traffic across vascular endothelial cells and further that the regulation of endogenous ceramide production by ceramide metabolizing enzyme inhibitors significantly altered the transcytosis of oxLDL across endothelial cells. It was found that acid sphingomyelinase inhibitor, desipramine (DES), andde novoceramide synthesis inhibitor, myriocin (MYR), both decreasing the endogenous ceramide production, significantly inhibited the transcytosis of oxLDL. Ceramidase inhibitor, N-oleoylethanolamine (NOE), and sphingomyelin synthase inhibitor, O-Tricyclo[5.2.1.02,6]dec-9-yl dithiocarbonate potassium salt (D609), both increasing the endogenous ceramide production, significantly upregulated the transcytosis of oxLDL.In vivo, injection of fluorescence labeled oxLDL into mice body also predisposed to the subendothelial retention of these oxidized lipids. The observations provided in the present study demonstrate that endogenous ceramide contributes to the transcytosis of oxLDL across endothelial cells and promotes the initiating step of atherosclerosis—the subendothelial retention of lipids in vascular wall.

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