scholarly journals In vitro rapid organization of endothelial cells into capillary-like networks is promoted by collagen matrices.

1983 ◽  
Vol 97 (5) ◽  
pp. 1648-1652 ◽  
Author(s):  
R Montesano ◽  
L Orci ◽  
P Vassalli

We have studied the behavior of cloned capillary endothelial cells grown inside a three dimensional collagen matrix. Cell monolayers established on the surface of collagen gels were covered with a second layer of collagen. This induced the monolayers of endothelial cells to reorganize into a network of branching and anastomosing capillary-like tubes. As seen by electron microscopy, the tubes were formed by at least two cells (in transverse sections) delimiting a narrow lumen. In addition, distinct basal lamina material was present between the abluminal face of the endothelial cells and the collagen matrix. These results showed that capillary endothelial cells have the capacity to form vessel-like structures with well-oriented cell polarity in vitro. They also suggest that an appropriate topological relationship of endothelial cells with collagen matrices, similar to that occurring in vivo, has an inducive role on the expression of this potential. This culture system provides a simple in vitro model for studying the factors involved in the formation of new blood vessels (angiogenesis).

1988 ◽  
Vol 89 (3) ◽  
pp. 441-447 ◽  
Author(s):  
R. Montesano ◽  
L. Orci

The endothelium of visceral capillaries is characterized by the occurrence of numerous fenestrae, which are usually bridged by a thin, single-layered diaphragm. Both in vivo and in vitro, diaphragmed fenestrae perforate the endothelial cell cytoplasm in the most attenuated regions of the cell. We report here that in capillary endothelial cells grown under experimental conditions promoting the development of intracellular lumina (for example, suspension within a three-dimensional collagen matrix), diaphragmed fenestrae can form in a unique, previously undescribed intracellular location - that is, within thin cytoplasmic septa separating contiguous luminal compartments.


2004 ◽  
Vol 126 (6) ◽  
pp. 699-708 ◽  
Author(s):  
Blayne A. Roeder ◽  
Klod Kokini ◽  
J. Paul Robinson ◽  
Sherry L. Voytik-Harbin

The ability to create extracellular matrix (ECM) constructs that are mechanically and biochemically similar to those found in vivo and to understand how their properties affect cellular responses will drive the next generation of tissue engineering strategies. To date, many mechanisms by which cells biochemically communicate with the ECM are known. However, the mechanisms by which mechanical information is transmitted between cells and their ECM remain to be elucidated. “Self-assembled” collagen matrices provide an in vitro-model system to study the mechanical behavior of ECM. To begin to understand how the ECM and the cells interact mechanically, the three-dimensional (3D) mechanical properties of the ECM must be quantified at the micro-(local) level in addition to information measured at the macro-(global) level. Here we describe an incremental digital volume correlation (IDVC) algorithm to quantify large (>0.05) 3D mechanical strains in the microstructure of 3D collagen matrices in response to applied mechanical loads. Strain measurements from the IDVC algorithm rely on 3D confocal images acquired from collagen matrices under applied mechanical loads. The accuracy and the precision of the IDVC algorithm was verified by comparing both image volumes collected in succession when no deformation was applied to the ECM (zero strain) and image volumes to which simulated deformations were applied in both 1D and 3D (simulated strains). Results indicate that the IDVC algorithm can accurately and precisely determine the 3D strain state inside largely deformed collagen ECMs. Finally, the usefulness of the algorithm was demonstrated by measuring the microlevel 3D strain response of a collagen ECM loaded in tension.


2017 ◽  
Vol 32 (3) ◽  
pp. 342-348
Author(s):  
Weiwei Jin ◽  
Yanxue Yin ◽  
Bo Zhang ◽  
Heng Mei ◽  
Huafang Wang ◽  
...  

Tissue factor is an upstream component of the cascade and a high-expressing factor under phathological conditions. In this study, a tissue factor cascade-targeted strategy for inducing local thrombosis was developed by combining ENP-HMME and photochemistry. In vitro study showed that protein EGFP-EGF1 conjugation to the nanoparticles could significantly contribute to the uptake of nanoparticles by tissue factor over-expressed brain capillary endothelial cells. Three-dimensional imaging and specklegram of brains in vivo showed that tissue factor cascade-targeted strategy successfully induced thrombosis of expected position. As shown by the in vivo multispectral fluorescent imaging, when ENP-HMME was combined with photochemistry, higher accumulation in the infarction hemisphere was observed, which might suggest that the photochemistry inducing tissue factor cascade recruited more ENP-HMME than HMME-loaded nanoparticles (NP-HMME). The data indicated the tissue factor cascade-targeted strategy has potential to induce local thrombosis, and might be applied in the treatment of a variety of hypervascular diseases.


Author(s):  
Susan Gallogly ◽  
Takeshi Fujisawa ◽  
John D. Hung ◽  
Mairi Brittan ◽  
Elizabeth M. Skinner ◽  
...  

Abstract Purpose Endothelial dysfunction is central to the pathogenesis of acute coronary syndrome. The study of diseased endothelium is very challenging due to inherent difficulties in isolating endothelial cells from the coronary vascular bed. We sought to isolate and characterise coronary endothelial cells from patients undergoing thrombectomy for myocardial infarction to develop a patient-specific in vitro model of endothelial dysfunction. Methods In a prospective cohort study, 49 patients underwent percutaneous coronary intervention with thrombus aspiration. Specimens were cultured, and coronary endothelial outgrowth (CEO) cells were isolated. CEO cells, endothelial cells isolated from peripheral blood, explanted coronary arteries, and umbilical veins were phenotyped and assessed functionally in vitro and in vivo. Results CEO cells were obtained from 27/37 (73%) atherothrombotic specimens and gave rise to cells with cobblestone morphology expressing CD146 (94 ± 6%), CD31 (87 ± 14%), and von Willebrand factor (100 ± 1%). Proliferation of CEO cells was impaired compared to both coronary artery and umbilical vein endothelial cells (population doubling time, 2.5 ± 1.0 versus 1.6 ± 0.3 and 1.2 ± 0.3 days, respectively). Cell migration was also reduced compared to umbilical vein endothelial cells (29 ± 20% versus 85±19%). Importantly, unlike control endothelial cells, dysfunctional CEO cells did not incorporate into new vessels or promote angiogenesis in vivo. Conclusions CEO cells can be reliably isolated and cultured from thrombectomy specimens in patients with acute coronary syndrome. Compared to controls, patient-derived coronary endothelial cells had impaired capacity to proliferate, migrate, and contribute to angiogenesis. CEO cells could be used to identify novel therapeutic targets to enhance endothelial function and prevent acute coronary syndromes.


1988 ◽  
Vol 16 (1) ◽  
pp. 48-53
Author(s):  
Marina Ziche ◽  
Lucia Morbidelli ◽  
Annalisa Rubino ◽  
Piero Dolara ◽  
Stefano Bianchi ◽  
...  

Polymorphonuclear neutrophil (PMN) interaction with vascular endothelial cells is the initial event in the migration of neutrophils through blood vessel walls before reaching inflammation sites in tissues. The interaction between fibroblasts and endothelial cells and their extracellular matrices might be modulated by the activation of neutrophils that occurs at inflammatory reaction sites. We have used an in vitro model to study PMN function, measuring the adhesion of human PMNs to capillary endothelial cells and fibroblasts grown in culture and to their extracellular matrices. The interaction was measured in basal conditions and in the presence of the chemotactic effector, formyl-methionyl-leucyl-phenylalanine (FMLP at the concentration of 10 7M). Adhesion was expressed by the number of adherent PMNs/mm2 on a histological specimen. Moreover, we have adapted a program for image analysis to quantify neutrophil adhesion. Three times more PMNs adhered to matrices than to monolayers, and adherence could be increased by the presence of 10-7M FMLP, except in the case of fibroblast monolayers. We found a good correlation between microscopic observation and computerised image analysis measuring PMN adhesiveness to extracellular matrices.


1982 ◽  
Vol 58 (1) ◽  
pp. 125-138
Author(s):  
C.G. Bellows ◽  
A.H. Melcher ◽  
J.E. Aubin

The relationship between the development of tension in sheets of fibroblasts and the orientation of these cells and collagen fibres in collagen gels was examined. Cell-containing, three-dimensional collagen gels were established in agarose-coated Epon dies measuring 10 mm X 4 mm X 4 mm, to which pieces of demineralized tooth and bone had been attached at opposite ends. Contraction of the gel into an opaque structure suspended between the two particles occurred over 24 h and resulted in concave upper and lateral surfaces and a flat to slightly concave lower surface. Initial orientation of the fibres along the tooth-bone axis was followed by similar orientation of the cells. Gels cast without cells exhibited no change in dimensions. Release of the tooth particle after 12 or 24 h of incubation led to shortening of the contracted gels 5 min following release. This shortening was significantly greater (P less than 0.001) than that of uncontracted or slightly contracted gels (1 h and 3 h incubation). Gels attached at one end only compacted around the site of attachment but did not show orientation of cells or fibres. Gels containing colcemid or cytochalasin D were only slightly compacted and did not develop tension. Collagen fibres, but not cell in colcemid-containing gels, showed some alignment; neither were aligned in the presence of cytochalasin D. These data suggest that both microtubules and microfilaments are necessary for alignment of cells and the establishment of tension between two points of attachment in collagen gels. Furthermore, they lend support to our previously advanced hypothesis that the development of tension between two points can result in the orientation of the cells along an axis connecting the points of attachment. This could provide a mechanism for the development of oriented fibre systems in vivo.


1983 ◽  
Vol 60 (1) ◽  
pp. 89-102
Author(s):  
D de Bono ◽  
C. Green

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.


2003 ◽  
Vol 31 (3) ◽  
pp. 273-276 ◽  
Author(s):  
Hanna Tähti ◽  
Heidi Nevala ◽  
Tarja Toimela

The purpose of this paper is to review the current state of development of advanced in vitro blood–brain barrier (BBB) models. The BBB is a special capillary bed that separates the blood from the central nervous system (CNS) parenchyma. Astrocytes maintain the integrity of the BBB, and, without astrocytic contacts, isolated brain capillary endothelial cells in culture lose their barrier characteristics. Therefore, when developing in vitro BBB models, it is important to add astrocytic factors into the culture system. Recently, novel filter techniques and co-culture methods have made it possible to develop models which resemble the in vivo functions of the BBB in an effective way. With a BBB model, kinetic factors can be added into the in vitro batteries used for evaluating the neurotoxic potential of chemicals. The in vitro BBB model also represents a useful tool for the in vitro prediction of the BBB permeability of drugs, and offers the possibility to scan a large number of drugs for their potential to enter the CNS. Cultured monolayers of brain endothelial cell lines or selected epithelial cell lines, combined with astrocyte and neuron cultures, form a novel three-dimensional technique for the screening of neurotoxic compounds.


2004 ◽  
Vol 287 (3) ◽  
pp. H994-H1002 ◽  
Author(s):  
Akinori Ueda ◽  
Masaki Koga ◽  
Mariko Ikeda ◽  
Susumu Kudo ◽  
Kazuo Tanishita

Shear stress stimulus is expected to enhance angiogenesis, the formation of microvessels. We determined the effect of shear stress stimulus on three-dimensional microvessel formation in vitro. Bovine pulmonary microvascular endothelial cells were seeded onto collagen gels with basic fibroblast growth factor to make a microvessel formation model. We observed this model in detail using phase-contrast microscopy, confocal laser scanning microscopy, and electron microscopy. The results show that cells invaded the collagen gel and reconstructed the tubular structures, containing a clearly defined lumen consisting of multiple cells. The model was placed in a parallel-plate flow chamber. A laminar shear stress of 0.3 Pa was applied to the surfaces of the cells for 48 h. Promotion of microvessel network formation was detectable after ∼10 h in the flow chamber. After 48 h, the length of networks exposed to shear stress was 6.17 (±0.59) times longer than at the initial state, whereas the length of networks not exposed to shear stress was only 3.30 (±0.41) times longer. The number of bifurcations and endpoints increased for networks exposed to shear stress, whereas the number of bifurcations alone increased for networks not exposed to shear stress. These results demonstrate that shear stress applied to the surfaces of endothelial cells on collagen gel promotes the growth of microvessel network formation in the gel and expands the network because of repeated bifurcation and elongation.


Sign in / Sign up

Export Citation Format

Share Document