Three-Dimensional Simulation of In Vitro Angiogenesis: Effects of Extracellular Matrix Structure and Density

2010 ◽  
Author(s):  
Lowell Taylor Edgar ◽  
James E. Guilkey ◽  
Clayton J. Underwood ◽  
Brenda Baggett ◽  
Urs Utzinger ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Chemical Factors ◽  
Dimensional Simulation ◽  
Endothelial Growth Factor ◽  
In Vitro Angiogenesis

The process of angiogenesis is regulated by both chemical and mechanical signaling. While the role of chemical factors such as vascular endothelial growth factor (VEGF) during angiogenesis has been extensively studied, the influence of the mechanostructural environment on new vessel generation has received significantly less attention. During angiogenesis, endothelial cells in the existing vasculature detach and migrate out into the surrounding extracellular matrix (ECM), forming tubular structures that eventually mature into new blood vessels. This process is modulated by the structure and composition of the ECM [1]. The ECM is then remodeled by endothelial cells in the elongating neovessel tip, resulting in matrix condensation and changes in fiber orientation [2]. The mechanism as to how angiogenic vasculature and the ECM influence each other is poorly understood.

Interaction between vascular endothelial cells and vascular intimal spindle-shaped cells in vitro

1983 ◽  
Vol 60 (1) ◽  
pp. 89-102
Author(s):  
D de Bono ◽  
C. Green
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Vascular Endothelial Cells ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Pure Cultures ◽  
Species Specific ◽  
Endothelial Growth Factor

The interactions between human or bovine vascular endothelial cells and fibroblast-like vascular intimal spindle-shaped cells have been studied in vitro, using species-specific antibodies to identify the different components in mixed cultures. Pure cultures of endothelial cells grow as uniform, nonoverlapping monolayers, but this growth pattern is lost after the addition of spindle cells, probably because the extracellular matrix secreted by the latter causes the endothelial cells to modify the way they are attached to the substrate. The result is a network of tubular aggregates of endothelial cells in a three-dimensional ‘polylayer’ of spindle-shaped cells. On the other hand, endothelial cells added to growth-inhibited cultures of spindle-shaped cells will grow in sheets over the surface of the culture. Human endothelial cells grown in contact with spindle-shaped cells have a reduced requirement for a brain-derived endothelial growth factor. The interactions of endothelial cells and other connective tissue cells in vitro may be relevant to the mechanisms of endothelial growth and blood vessel formation in vivo, and emphasize the potential importance of extracellular matrix in controlling endothelial cell behaviour.

scholarly journals Vascular Endothelial Growth Factor Induces Endothelial Fenestrations In Vitro

1998 ◽  
Vol 140 (4) ◽  
pp. 947-959 ◽  
Author(s):  
Sybille Esser ◽  
Karen Wolburg ◽  
Hartwig Wolburg ◽  
Georg Breier ◽  
Teymuras Kurzchalia ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Epithelial Cells ◽  
Choroid Plexus ◽  
Vascular Endothelial ◽  
Caveolin 1 ◽  
Endothelial Growth Factor

Abstract. Vascular endothelial growth factor (VEGF) is an important regulator of vasculogenesis, angiogenesis, and vascular permeability. In contrast to its transient expression during the formation of new blood vessels, VEGF and its receptors are continuously and highly expressed in some adult tissues, such as the kidney glomerulus and choroid plexus. This suggests that VEGF produced by the epithelial cells of these tissues might be involved in the induction or maintenance of fenestrations in adjacent endothelial cells expressing the VEGF receptors. Here we describe a defined in vitro culture system where fenestrae formation was induced in adrenal cortex capillary endothelial cells by VEGF, but not by fibroblast growth factor. A strong induction of endothelial fenestrations was observed in cocultures of endothelial cells with choroid plexus epithelial cells, or mammary epithelial cells stably transfected with cDNAs for VEGF 120 or 164, but not with untransfected cells. These results demonstrate that, in these cocultures, VEGF is sufficient to induce fenestrations in vitro. Identical results were achieved when the epithelial cells were replaced by an epithelial-derived basal lamina-type extracellular matrix, but not with collagen alone. In this defined system, VEGF-mediated induction of fenestrae was always accompanied by an increase in the number of fused diaphragmed caveolae-like vesicles. Caveolae, but not fenestrae, were labeled with a caveolin-1–specific antibody both in vivo and in vitro. VEGF stimulation led to VEGF receptor tyrosine phosphorylation, but no change in the distribution, phosphorylation, or protein level of caveolin-1 was observed. We conclude that VEGF in the presence of a basal lamina-type extracellular matrix specifically induces fenestrations in endothelial cells. This defined in vitro system will allow further study of the signaling mechanisms involved in fenestrae formation, modification of caveolae, and vascular permeability.

Inhibition of In Vitro Angiogenesis by Platelet Factor-4–Derived Peptides and Mechanism of Action

Blood ◽  
1999 ◽  
Vol 94 (3) ◽  
pp. 984-993 ◽  
Author(s):  
Valérie Jouan ◽  
Xavier Canron ◽  
Monica Alemany ◽  
Jacques P. Caen ◽  
Gérard Quentin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Growth Factor ◽  
Three Dimensional ◽  
Tube Formation ◽  
Platelet Factor 4 ◽  
Vascular Endothelial ◽  
Heparin Binding ◽  
Platelet Factor ◽  
Endothelial Growth Factor

In this study, we examined in detail the interaction of platelet factor-4 (PF-4) with fibroblast growth factor-2 (FGF-2) and vascular endothelial growth factor (VEGF) and the effect of PF-4–derived synthetic peptides. We show that a peptide between amino acids 47 and 70 that contains the heparin-binding lysine-rich site inhibits FGF-2 or VEGF function. This is based on the following observations: PF-4 peptide 47-70 inhibited FGF-2 or VEGF binding to endothelial cells; it inhibited FGF-2 or VEGF binding to FGFRs or VEGFRs in heparan sulfate–deficient CHO cells transfected with FGFR1 (CHOFGFR1) or VEGFR2 (CHOmVEGFR2) cDNA; it blocked proliferation or tube formation in three-dimensional angiogenesis assays; and, finally, it competed with the direct association of 125I-PF-4 with FGF-2 or VEGF, respectively, and inhibited heparin-induced FGF-2 dimerization. A shorter C-terminal peptide (peptide 58-70), which still contained the heparin-binding lysin-rich site, had no effect. Peptide 17-58, which is located in the central part of the molecule, although it does not inhibit FGF-2 or VEGF binding or biologic activity in endothelial cells, inhibited heparin-dependent binding of125I-FGF-2 or 125I-VEGF to CHOmFGFR1 or CHOmVEGFR2 cells, respectively. Shorter peptides (peptides 34-58 and 47-58) did not show any of these effects.

Tensional forces in fibrillar extracellular matrices control directional capillary sprouting

1999 ◽  
Vol 112 (19) ◽  
pp. 3249-3258 ◽  
Author(s):  
T. Korff ◽  
H.G. Augustin
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Three Dimensional ◽  
Type I ◽  
Cellular Delivery ◽  
Form Complex ◽  
Cell Spheroid ◽  
In Vitro Angiogenesis

During angiogenesis, anastomosing capillary sprouts align to form complex three-dimensional networks of new blood vessels. Using an endothelial cell spheroid model that was developed to study endothelial cell differentiation processes, we have devised a novel collagen gel-based three-dimensional in vitro angiogenesis assay. In this assay, cell number-defined, gel-embedded endothelial cell spheroids act as a cellular delivery device, which serves as a focal starting point for the sprouting of lumenized capillary-like structures that can be induced to form complex anastomosing networks. Formation of capillary anastomoses is associated with tensional remodeling of the collagen matrix and directional sprouting of outgrowing capillaries towards each other. To analyze whether directional sprouting is dependent on cytokine gradients or on endothelial cell-derived tractional forces transduced through the extracellular matrix, we designed a matrix tension generator that enables the application of defined tensional forces on the extracellular matrix. Using this matrix tension generator, causal evidence is presented that tensional forces on a fibrillar extracellular matrix such as type I collagen, but not fibrin, are sufficient to guide directional outgrowth of endothelial cells. RGD peptides but not control RAD peptides disrupted the integrity of sprouting capillary-like structures and induced detachment of outgrowing endothelial cells cultured on top of collagen gels, but did not inhibit primary outgrowth of endothelial cells. The data establish the endothelial cell spheroid-based three-dimensional angiogenesis technique as a standardized, highly reproducible quantitative assay for in vitro angiogenesis studies and demonstrate that integrin-dependent matrix tensional forces control directional capillary sprouting and network formation.

scholarly journals Telocytes are major constituents of the angiogenic apparatus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Soha A. Soliman
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Three Dimensional ◽  
Vascular Endothelial ◽  
Vascular Growth ◽  
Transmission Electron ◽  
Dimensional Network ◽  
And Migration ◽  
Endothelial Growth Factor

AbstractThe current study investigated role of telocytes (TCs) in angiogenesis during embryonic development of quail using immunohistochemistry (IHC), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The angiogenic apparatus consisted of TCs, endothelial cells, and macrophages. TCs were identified morphologically by their telopodes and podoms using TEM and SEM and immunohistochemically using CD34, and vascular endothelial growth factor (VEGF). TCs also expressed CD68. TCs formed a three-dimensional network and established direct contact with blood vessels, sprouting endothelial cells, and active macrophages, while exerting their effect through paracrine signaling. VEGF was also expressed by endothelial cells and macrophages. Matrix metalloproteinase–9 (MMP-9) was expressed by TCs, endothelial cells, and macrophages. In conclusion, the expression of VEGF by TCs, endothelial cells, and macrophages is required for the proliferation and migration of endothelial cells and vascular growth. The expression of MMP-9 by TCs, endothelial cells, and macrophages is essential for the degradation of extracellular matrix (ECM) components during neoangiogenesis. Macrophages may facilitate phagocytosis and elimination of the degraded ECM components.

Nerve growth factor is critical requirement for in vitro angiogenesis in gastric endothelial cells

2016 ◽  
Vol 311 (5) ◽  
pp. G981-G987 ◽  
Author(s):  
Amrita Ahluwalia ◽  
Michael K. Jones ◽  
Tomasz Brzozowski ◽  
Andrzej S. Tarnawski
Keyword(s):  
Endothelial Cells ◽  
Nerve Growth Factor ◽  
Growth Factor ◽  
Mucosal Injury ◽  
Vascular Endothelial ◽  
Nerve Growth ◽  
Critical Requirement ◽  
Endothelial Growth Factor ◽  
In Vitro Angiogenesis

Angiogenesis is critical for the healing of gastric mucosal injury and is considered to be primarily regulated by vascular endothelial growth factor (VEGF), the fundamental proangiogenic factor. The role of nerve growth factor (NGF) in gastric angiogenesis is unknown. We examined the expression of NGF and its TrkA receptor in endothelial cells (ECs) isolated from gastric mucosa of rats (GMECs), the effect of NGF treatment on in vitro angiogenesis in GMECs, and, the mechanisms underlying NGF's proangiogenic actions. Isolated GMECs from Fisher rats were treated with vehicle, NGF (10-1,000 ng/ml), VEGF (20 ng/ml), or NGF+VEGF. To determine whether and to what extent NGF is critical for angiogenesis in GMECs, we silenced NGF expression using specific siRNA and examined in vitro angiogenesis with and without treatment with exogenous NGF and/or VEGF. Treatment of GMECs with NGF significantly increased in vitro angiogenesis similar to that seen in GMECs treated with VEGF. Silencing of NGF in GMECs abolished angiogenesis, and this effect was reversed only by exogenous NGF but not VEGF, which indicates a direct proangiogenic action of NGF on GMECs that is, at least in part, distinct and independent of VEGF. NGF's proangiogenic action on GMECs was mediated via PI3-K/Akt signaling. This study showed for the first time that gastric mucosal ECs express NGF and its receptor TrkA and that NGF is critical for angiogenesis in these cells.

scholarly journals Porcine ovarian cortex-derived putative stem cells can differentiate into endothelial cells in vitro

2021 ◽  
Author(s):  
Kamil Wartalski ◽  
Gabriela Gorczyca ◽  
Jerzy Wiater ◽  
Zbigniew Tabarowski ◽  
Małgorzata Duda
Keyword(s):  
Stem Cells ◽  
Vascular Endothelial Growth Factor ◽  
Endothelial Cells ◽  
Growth Factor ◽  
Primary Component ◽  
Marker Genes ◽  
Vascular Endothelial ◽  
Ovarian Cortex ◽  
Endothelial Growth Factor

AbstractEndothelial cells (ECs), the primary component of the vasculature, play a crucial role in neovascularization. However, the number of endogenous ECs is inadequate for both experimental purposes and clinical applications. Porcine ovarian putative stem cells (poPSCs), although not pluripotent, are characterized by great plasticity. Therefore, this study aimed to investigate whether poPSCs have the potential to differentiate into cells of endothelial lineage. poPSCs were immunomagnetically isolated from postnatal pig ovaries based on the presence of SSEA-4 protein. Expression of mesenchymal stem cells (MSCs) markers after pre-culture, both at the level of mRNA: ITGB1, THY, and ENG and corresponding protein: CD29, CD90, and CD105 were significantly higher compared to the control ovarian cortex cells. To differentiate poPSCs into ECs, inducing medium containing vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF), epidermal growth factor (EGF), ascorbic acid, and heparin was applied. After 14 days, poPSC differentiation into ECs was confirmed by immunofluorescence staining for vascular endothelial cadherin (VECad) and vascular endothelial growth factor receptor-2 (VEGFR-2). Semi-quantitative WB analysis of these proteins confirmed their high abundance. Additionally, qRT-PCR showed that mRNA expression of corresponding marker genes: CDH5, KDR was significantly higher compared with undifferentiated poPSCs. Finally, EC functional status was confirmed by the migration test that revealed that they were capable of positive chemotaxis, while tube formation assay demonstrated their ability to develop capillary networks. In conclusion, our results provided evidence that poPSCs may constitute the MSC population in the ovary and confirmed that they might be a potential source of ECs for tissue engineering.

Differential roles of ICAM-1 and E-selectin in polymorphonuclear leukocyte-induced angiogenesis

2002 ◽  
Vol 282 (4) ◽  
pp. C917-C925 ◽  
Author(s):  
Masako Yasuda ◽  
Shunichi Shimizu ◽  
Kyoko Ohhinata ◽  
Shinji Naito ◽  
Shogo Tokuyama ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Polymorphonuclear Leukocytes ◽  
Vascular Endothelial Cell ◽  
Collagen Gel ◽  
Intercellular Adhesion Molecule ◽  
Vascular Endothelial ◽  
Endothelial Cell Cultures ◽  
In Vitro Angiogenesis

Ets-1, which stimulates metalloproteinase gene transcription, has a key role in angiogenesis. We first examined whether activated polymorphonuclear leukocytes (PMNs) enhanced angiogenesis through the induction of Ets-1. Addition of activated PMNs to endothelial cells stimulated both in vitro angiogenesis in collagen gel and Ets-1 expression. Both angiogenesis and Ets-1 expression induced by PMNs were reduced by ets-1 antisense oligonucleotide, suggesting that Ets-1 is an important factor in PMN-induced angiogenesis. Although intercellular adhesion molecule (ICAM)-1 and E-selectin are involved in PMN-induced angiogenesis, the mechanisms underlying their roles in angiogenesis have yet to be elucidated. PMN-induced Ets-1 expression was reduced by a monoclonal antibody against ICAM-1 but not E-selectin despite the inhibition of PMN-induced angiogenesis by both antibodies. Moreover, the stimulation of angiogenesis by H2O2without PMNs was inhibited by a monoclonal antibody to E-selectin but not ICAM-1. These findings suggested that ICAM-1 in endothelial cells may act as a signaling receptor to induce Ets-1 expression, whereas E-selectin seems to function in the formation of tubelike structures in vascular endothelial cell cultures.

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