scholarly journals The Role of Methionine Aminopeptidase 2 in Lymphangiogenesis

2020 ◽  
Vol 21 (14) ◽  
pp. 5148
Author(s):  
Rawnaq Esa ◽  
Eliana Steinberg ◽  
Dvir Dror ◽  
Ouri Schwob ◽  
Mehrdad Khajavi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Function ◽  
Loss Of Function ◽  
Methionine Aminopeptidase ◽  
Zebrafish Model ◽  
Lymphatic Capillary ◽  
Intracellular Enzyme

During the metastasis process, tumor cells invade the blood circulatory system directly from venous capillaries or indirectly via lymphatic vessels. Understanding the relative contribution of each pathway and identifying the molecular targets that affect both processes is critical for reducing cancer spread. Methionine aminopeptidase 2 (MetAp2) is an intracellular enzyme known to modulate angiogenesis. In this study, we investigated the additional role of MetAp2 in lymphangiogenesis. A histological staining of tumors from human breast-cancer donors was performed in order to detect the level and the localization of MetAp2 and lymphatic capillaries. The basal enzymatic level and activity in vascular and lymphatic endothelial cells were compared, followed by loss of function studies determining the role of MetAp2 in lymphangiogenesis in vitro and in vivo. The results from the histological analyses of the tumor tissues revealed a high MetAp2 expression, with detectable sites of co-localization with lymphatic capillaries. We showed slightly reduced levels of the MetAp2 enzyme and MetAp2 mRNA expression and activity in primary lymphatic cells when compared to the vascular endothelial cells. The genetic and biochemical manipulation of MetAp2 confirmed the dual activity of the enzyme in both vascular and lymphatic remodulation in cell function assays and in a zebrafish model. We found that cancer-related lymphangiogenesis is inhibited in murine models following MetAp2 inhibition treatment. Taken together, our study provides an indication that MetAp2 is a significant contributor to lymphangiogenesis and carries a dual role in both vascular and lymphatic capillary formation. Our data suggests that MetAp2 inhibitors can be effectively used as anti-metastatic broad-spectrum drugs.

Abstract 16761: Long Non-coding RNA Meg3 Controls Endothelial Cell Function: Implications for Endothelial Aging and Senescence (Best of Basic Science Abstract)

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Reinier Boon ◽  
Patrick Hofmann ◽  
Katharina Michalik ◽  
Andrea Knau ◽  
Yuliya Ponomareva ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Cell Function ◽  
Regulation Of Gene Expression ◽  
Limb Ischemia ◽  
Loss Of Function ◽  
Endothelial Cell Function ◽  
Aged Mice

The majority of transcribed RNA does not encode proteins, but may function as regulatory RNA. Long non-coding RNAs (lncRNAs) have been described to play an important role in many biological processes, including epigenetic regulation of gene expression. To determine the expression and functional role of lncRNAs in endothelial cells, we performed RNA deep sequencing of human umbilical venous endothelial cells (ECs). Among the highest expressed lncRNAs, we identified Meg3 (35.3±0.6 RPKM), which was increased in replicative senescent HUVECs in vitro (passage 16/17 vs 2/3, 2.9±0.99-fold). Interestingly, Meg3 is induced in the intima of aged mice and correlates with age in human hearts (p=0.016). In HUVECs, Meg3 localizes to the nucleus and is also induced by hypoxia (4.08±0.78-fold, p<0.05). Silencing of Meg3 using LNA-GapmeRs induced angiogenic sprouting and proliferation of endothelial cells in vitro (1.4±0.14-fold, P<0.05) and repressed SA-β-galactosidase activity. Conversely, lentiviral overexpression of Meg3 inhibited sprouting angiogenesis and cell cycle progression, although splicing isoforms of Meg3 show differential effects. Mechanistically, RNA immunoprecipitation showed that Meg3 associates specifically to H3K27me3, a silencing chromatin mark, and interacts with EZH2, a histone methyl transferase. Silencing of Meg3 in HUVECs represses, and overexpression of Meg3 induces, global gene expression, as measured by exon array analysis. As Meg3 was described to recruit Jarid2 to chromatin, we determined whether Meg3 requires Jarid2. The Meg3 loss-of-function induced repression of proliferation was normalized after silencing Jarid2, indicating that Meg3 effects are at least partly Jarid2-dependent. Finally, silencing of Meg3 in aged mice in vivo using gapmeRs in combination with hind limb ischemia significantly repressed Meg3 levels in the hindlimb and induced recovery of perfusion compared to control mice. Capillary and arteriole density was also markedly induced after silencing Meg3. These results demonstrate that silencing Meg3 may be a potential strategy to reduce endothelial senescence or increase regenerative angiogenesis.

scholarly journals Hyperglycaemia up-regulates placental growth factor (PlGF) expression and secretion in endothelial cells via suppression of PI3 kinase-Akt signalling and activation of FOXO1

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Samir Sissaoui ◽  
Stuart Egginton ◽  
Ling Ting ◽  
Asif Ahmed ◽  
Peter W. Hewett
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Endothelial Dysfunction ◽  
Akt Activation ◽  
Forkhead Box ◽  
Pi3k Activity ◽  
Binding Sequence

AbstractPlacenta growth factor (PlGF) is a pro-inflammatory angiogenic mediator that promotes many pathologies including diabetic complications and atherosclerosis. Widespread endothelial dysfunction precedes the onset of these conditions. As very little is known of the mechanism(s) controlling PlGF expression in pathology we investigated the role of hyperglycaemia in the regulation of PlGF production in endothelial cells. Hyperglycaemia stimulated PlGF secretion in cultured primary endothelial cells, which was suppressed by IGF-1-mediated PI3K/Akt activation. Inhibition of PI3K activity resulted in significant PlGF mRNA up-regulation and protein secretion. Similarly, loss or inhibition of Akt activity significantly increased basal PlGF expression and prevented any further PlGF secretion in hyperglycaemia. Conversely, constitutive Akt activation blocked PlGF secretion irrespective of upstream PI3K activity demonstrating that Akt is a central regulator of PlGF expression. Knock-down of the Forkhead box O-1 (FOXO1) transcription factor, which is negatively regulated by Akt, suppressed both basal and hyperglycaemia-induced PlGF secretion, whilst FOXO1 gain-of-function up-regulated PlGF in vitro and in vivo. FOXO1 association to a FOXO binding sequence identified in the PlGF promoter also increased in hyperglycaemia. This study identifies the PI3K/Akt/FOXO1 signalling axis as a key regulator of PlGF expression and unifying pathway by which PlGF may contribute to common disorders characterised by endothelial dysfunction, providing a target for therapy.

scholarly journals Metformin-stimulated AMPK-α1 promotes microvascular repair in acute lung injury

2013 ◽  
Vol 305 (11) ◽  
pp. L844-L855 ◽  
Author(s):  
Ming-Yuan Jian ◽  
Mikhail F. Alexeyev ◽  
Paul E. Wolkowicz ◽  
Jaroslaw W. Zmijewski ◽  
Judy R. Creighton
Keyword(s):  
Endothelial Cells ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Ex Vivo ◽  
Endothelial Permeability ◽  
Beneficial Effects ◽  
Isolated Lung

Acute lung injury secondary to sepsis is a leading cause of mortality in sepsis-related death. Present therapies are not effective in reversing endothelial cell dysfunction, which plays a key role in increased vascular permeability and compromised lung function. AMP-activated protein kinase (AMPK) is a molecular sensor important for detection and mediation of cellular adaptations to vascular disruptive stimuli. In this study, we sought to determine the role of AMPK in resolving increased endothelial permeability in the sepsis-injured lung. AMPK function was determined in vivo using a rat model of endotoxin-induced lung injury, ex vivo using the isolated lung, and in vitro using cultured rat pulmonary microvascular endothelial cells (PMVECs). AMPK stimulation using N1-(α-d-ribofuranosyl)-5-aminoimidizole-4-carboxamide or metformin decreased the LPS-induced increase in permeability, as determined by filtration coefficient ( Kf) measurements, and resolved edema as indicated by decreased wet-to-dry ratios. The role of AMPK in the endothelial response to LPS was determined by shRNA designed to decrease expression of the AMPK-α1 isoform in capillary endothelial cells. Permeability, wounding, and barrier resistance assays using PMVECs identified AMPK-α1 as the molecule responsible for the beneficial effects of AMPK in the lung. Our findings provide novel evidence for AMPK-α1 as a vascular repair mechanism important in the pulmonary response to sepsis and identify a role for metformin treatment in the management of capillary injury.

The recombinant lectin-like domain of thrombomodulin inhibits angiogenesis through interaction with Lewis Y antigen

Blood ◽  
2012 ◽  
Vol 119 (5) ◽  
pp. 1302-1313 ◽  
Author(s):  
Cheng-Hsiang Kuo ◽  
Po-Ku Chen ◽  
Bi-Ing Chang ◽  
Meng-Chen Sung ◽  
Chung-Sheng Shi ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Egf Receptor ◽  
Tube Formation ◽  
Endothelial Tube Formation ◽  
A Cell ◽  
Lewis Y ◽  
Tm Domain

AbstractLewis Y Ag (LeY) is a cell-surface tetrasaccharide that participates in angiogenesis. Recently, we demonstrated that LeY is a specific ligand of the recombinant lectin-like domain of thrombomodulin (TM). However, the biologic function of interaction between LeY and TM in endothelial cells has never been investigated. Therefore, the role of LeY in tube formation and the role of the recombinant lectin-like domain of TM—TM domain 1 (rTMD1)—in antiangiogenesis were investigated. The recombinant TM ectodomain exhibited lower angiogenic activity than did the recombinant TM domains 2 and 3. rTMD1 interacted with soluble LeY and membrane-bound LeY and inhibited soluble LeY-mediated chemotaxis of endothelial cells. LeY was highly expressed on membrane ruffles and protrusions during tube formation on Matrigel. Blockade of LeY with rTMD1 or Ab against LeY inhibited endothelial tube formation in vitro. Epidermal growth factor (EGF) receptor in HUVECs was LeY modified. rTMD1 inhibited EGF receptor signaling, chemotaxis, and tube formation in vitro, and EGF-mediated angiogenesis and tumor angiogenesis in vivo. We concluded that LeY is involved in vascular endothelial tube formation and rTMD1 inhibits angiogenesis via interaction with LeY. Administration of rTMD1 or recombinant adeno-associated virus vector carrying TMD1 could be a promising antiangiogenesis strategy.

Role of endothelial cells in regulating hemoglobin-induced changes in lymphatic pumping

1992 ◽  
Vol 263 (6) ◽  
pp. H1880-H1887 ◽  
Author(s):  
R. M. Elias ◽  
J. Eisenhoffer ◽  
M. G. Johnston
Keyword(s):  
Endothelial Cells ◽  
Smooth Muscle ◽  
Inhibitory Effect ◽  
Direct Inhibitory Effect ◽  
Induced Changes ◽  
Lymphatic Pumping ◽  
Pumping Activity

Studies with a sheep isolated duct preparation in vivo demonstrated that the route of administration of hemoglobin was important in demonstrating its inhibitory effect on lymphatic pumping. With autologous oxyhemoglobin administered intravenously (final plasma concentration 5 x 10(-5) M), pumping was not inhibited. However, the addition of oxyhemoglobin (5 x 10(-5) M) into the reservoir (lumen of the duct) resulted in > 95% inhibition of pumping. The extraluminal administration of oxyhemoglobin (10(-5) M) to bovine mesenteric lymphatics in vitro resulted in a 40% inhibition of pumping, whereas the introduction of oxyhemoglobin (10(-5) M) into the lumen of the vessels suppressed pumping 95%. In vessels mechanically denuded of endothelium, intraluminal oxyhemoglobin inhibited pumping 50%. These results suggested that oxyhemoglobin depressed pumping through an effect on both smooth muscle and endothelium. Once pumping was inhibited with oxyhemoglobin administration, stimulation of the duct with elevations in transmural pressure restored pumping activity when endothelial cells were present. However, in the absence of endothelium, pumping decreased with increases in distending pressures. We conclude that oxyhemoglobin has a direct inhibitory effect on lymphatic smooth muscle. The ability of oxyhemoglobin to alter the pressure range over which the lymph pump operates appears to be dependent on an intact endothelium.

scholarly journals The tight junctions protein Claudin-5 limits endothelial cell motility

2020 ◽  
pp. jcs.248237
Author(s):  
Zhenguo Yang ◽  
Shuilong Wu ◽  
Federica Fontana ◽  
Yanyu Li ◽  
Wei Xiao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Motility ◽  
Dorsal Aorta ◽  
Aortic Endothelial Cells ◽  
Differential Adhesion ◽  
Adhesive Forces

Steinberg's differential adhesion hypothesis suggests that adhesive mechanisms are important for sorting of cells and tissues during morphogenesis (Steinberg, 2007). During zebrafish vasculogenesis, endothelial cells sort into arterial and venous vessel beds but it is unknown whether this involves adhesive mechanisms. Claudins are tight junction proteins regulating the permeability of epithelial and endothelial tissue barriers. Previously, the roles of Claudins during organ development have exclusively been related to their canonical functions in determining paracellular permeability. Here, we use atomic force microscopy to quantify Claudin-5-dependent adhesion and find that this strongly contributes to the adhesive forces between arterial endothelial cells. Based on genetic manipulations, we reveal a non-canonical role of Claudin-5a during zebrafish vasculogenesis, which involves the regulation of adhesive forces between adjacent dorsal aortic endothelial cells. In vitro and in vivo studies demonstrate that loss of Claudin-5 results in increased motility of dorsal aorta endothelial cells and in a failure of the dorsal aorta to lumenize. Our findings uncover a novel role of Claudin-5 in limiting arterial endothelial cell motility, which goes beyond its traditional sealing function during embryonic development.

Contribution of Natural Killer Cells to Inhibition of Angiogenesis by Interleukin-12

Blood ◽  
1999 ◽  
Vol 93 (5) ◽  
pp. 1612-1621 ◽  
Author(s):  
Lei Yao ◽  
Cecilia Sgadari ◽  
Keizo Furuke ◽  
Eda T. Bloom ◽  
Julie Teruya-Feldstein ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Nk Cells ◽  
Natural Killer ◽  
Cell Function ◽  
Nk Cell ◽  
Primary Cultures ◽  
Interleukin 12 ◽  
Ifn Γ

Abstract Interleukin-12 (IL-12) inhibits angiogenesis in vivo by inducing interferon-γ (IFN-γ) and other downstream mediators. Here, we report that neutralization of natural killer (NK) cell function with antibodies to either asialo GM1 or NK 1.1 reversed IL-12 inhibition of basic fibroblast growth factor (bFGF)-induced angiogenesis in athymic mice. By immunohistochemistry, those sites where bFGF-induced neovascularization was inhibited by IL-12 displayed accumulation of NK cells and the presence of IP-10–positive cells. Based on expression of the cytolytic mediators perforin and granzyme B, the NK cells were locally activated. Experimental Burkitt lymphomas treated locally with IL-12 displayed tumor tissue necrosis, vascular damage, and NK-cell infiltration surrounding small vessels. After activation in vitro with IL-12, NK cells from nude mice became strongly cytotoxic for primary cultures of syngeneic aortic endothelial cells. Cytotoxicity was neutralized by antibodies to IFN-γ. These results document that NK cells are required mediators of angiogenesis inhibition by IL-12, and provide evidence that NK-cell cytotoxicity of endothelial cells is a potential mechanism by which IL-12 can suppress neovascularization.

Nitric oxide mediates mitogenic effect of VEGF on coronary venular endothelium

1996 ◽  
Vol 270 (1) ◽  
pp. H411-H415 ◽  
Author(s):  
L. Morbidelli ◽  
C. H. Chang ◽  
J. G. Douglas ◽  
H. J. Granger ◽  
F. Ledda ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Growth Factor ◽  
No Synthase ◽  
Mitogenic Effect ◽  
Microvascular Endothelium ◽  
Proliferative Effect

Vascular endothelial growth factor (VEGF) is a secreted protein that is a specific growth factor for endothelial cells. We have recently demonstrated that nitric oxide (NO) donors and vasoactive peptides promoting NO-mediated vasorelaxation induce angiogenesis in vivo as well as endothelial cell growth and motility in vitro; in contrast, inhibitors of NO synthase suppress angiogenesis. In this study we investigated the role of NO in mediating the mitogenic effect of VEGF on cultured microvascular endothelium isolated from coronary postcapillary venules. VEGF induced a dose-dependent increase in cell proliferation and DNA synthesis. The role of NO was determined by monitoring proliferation or guanosine 3',5'-cyclic monophosphate (cGMP) levels in the presence and absence of NO synthase blockers. The proliferative effect evoked by VEGF was reduced by pretreatment of the cells with NO synthase inhibitors. Exposure of the cells to VEGF induced a significant increment in cGMP levels. This effect was potentiated by superoxide dismutase addition and was abolished by NO synthase inhibitors. VEGF stimulates proliferation of postcapillary endothelial cells through the production of NO and cGMP accumulation.

Platelet-Derived Microparticles Induce Angiogenesis and Stimulate Post-Ischemic Revascularization.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3916-3916
Author(s):  
Olga Dashevsky ◽  
Alexander Brill ◽  
Julia Rivo ◽  
David Varon
Keyword(s):  
Endothelial Cells ◽  
Aortic Ring ◽  
In Vivo Model ◽  
Preliminary Evaluation ◽  
Vegf Receptor ◽  
In Vivo Models ◽  
Ischemic Region

Abstract Platelet attachment to the subcellular matrix at injured sites of the vasculature is followed by their activation and release of microparticles. Platelet-derived microparticles (PMP) have been shown to be involved in the regulation of hemostasis. However, little is known about the role of PMP in the regulation of angiogenesis and related clinical conditions. We have recently demonstrated that platelets as a cellular system induce angiogenic responses both in vitro and in vivo. In the present study, we investigated the potential role of PMP in angiogenesis. A strong dose-dependent pro-angiogenic effect of PMP in the rat aortic ring model (5.3±2.1 mm2 surface covered with sprouting vessels versus 0.24±0.2 mm2 in the control, p<0.001) was observed. This effect was reversed by selective inhibition of VEGF, bFGF and PDGF (surface covered with vessels 0.7±0.5 mm2, 1.7±1.5 mm2, and 2.4±1.2 mm2, respectively, p<0.02 versus control), but not by inhibition of heparanase (5.1±0.8 mm2, p>0.5 versus control). PMP exert their stimulatory effect via PI3-kinase, Src kinase and ERK, whereas protein kinase C seems not to be involved, as judged by the aortic ring sprouting model. Using confocal and electron microscopy, we also demonstrate that PMP bind to non-activated endothelial cells. In addition, PMP markedly increased invasion of human endothelial cells through a layer of matrigel. This effect was abolished by an inhibitor of VEGF receptor tyrosine phosphorylation or laminaran sulfate (heparanase inhibitor). It was also partially reduced by PDGF blocking mAb, whereas blocking of bFGF had no effect. Furthermore, we have demonstrated that PMP induce angiogenesis in an in vivo model, in which beads (30 μl) of 4% agarose gel containing the substances under study were transplanted subcutaneously into mice. Image analysis of the capillary area revealed the following: control beads − 0.2±0.05 mm2, VEGF + bFGF containing beads − 4.8±1.1 mm2, PMP (100 μg/ml) containing beads − 5.1±1.3 mm2, p<0.001 versus control. The latter finding was further supported by immunohistochemical staining of the skin in the vicinity of the beads for von Willebrand factor, a marker of endothelial cells (control − 4.0±3.2, VEGF+bFGF − 12±4.4, PMP − 17±6.5 capillaries per view field, p<0.05 versus control). Finally, we explored the potential effect of PMP in a rat myocardial infarction model. Ischemia was induced by LAD ligation followed by injection of either PMP or PBS into the ischemic region. Preliminary evaluation of the LAD myocardial territory in sham-operated animals revealed 157±42.0 capillaries per view field. In contrast, number of capillaries observed 3 weeks after induction of ischemia was reduced to 34±21.5. When PMP were injected into the ischemic region, there was an increase in capillary number up to 97±27.3. In conclusion, PMP induce angiogenesis in both in vitro and in vivo models. Local injection of PMP into the ischemic myocardium may improve revascularization.

Sign in / Sign up

Export Citation Format

Share Document