scholarly journals Mechanical Interaction of Angiogenic Microvessels With the Extracellular Matrix

2014 ◽  
Vol 136 (2) ◽  
Author(s):  
Lowell T. Edgar ◽  
James B. Hoying ◽  
Urs Utzinger ◽  
Clayton J. Underwood ◽  
Laxminarayanan Krishnan ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Blood Vessels ◽  
Element Model ◽  
Mechanical Interaction ◽  
Matrix Mechanics ◽  
Two Photon ◽  
Cell Matrix ◽  
Vascular Elements ◽  
The Matrix

Angiogenesis is the process by which new blood vessels sprout from existing blood vessels, enabling new vascular elements to be added to an existing vasculature. This review discusses our investigations into the role of cell-matrix mechanics in the mechanical regulation of angiogenesis. The experimental aspects of the research are based on in vitro experiments using an organ culture model of sprouting angiogenesis with the goal of developing new treatments and techniques to either promote or inhibit angiogenic outgrowth, depending on the application. Computational simulations were performed to simulate angiogenic growth coupled to matrix deformation, and live two-photon microscopy was used to obtain insight into the dynamic mechanical interaction between angiogenic neovessels and the extracellular matrix. In these studies, we characterized how angiogenic neovessels remodel the extracellular matrix (ECM) and how properties of the matrix such as density and boundary conditions influence vascular growth and alignment. Angiogenic neovessels extensively deform and remodel the matrix through a combination of applied traction, proteolytic activity, and generation of new cell-matrix adhesions. The angiogenic phenotype within endothelial cells is promoted by ECM deformation and remodeling. Sensitivity analysis using our finite element model of angiogenesis suggests that cell-generated traction during growth is the most important parameter controlling the deformation of the matrix and, therefore, angiogenic growth and remodeling. Live two-photon imaging has also revealed numerous neovessel behaviors during angiogenesis that are poorly understood such as episodic growth/regression, neovessel colocation, and anastomosis. Our research demonstrates that the topology of a resulting vascular network can be manipulated directly by modifying the mechanical interaction between angiogenic neovessels and the matrix.

Variants of integrin β4 subunit in human endometrial adenocarcinoma cells: mediators of ECM-induced differentiation?

1996 ◽  
Vol 74 (6) ◽  
pp. 867-873 ◽  
Author(s):  
Elisabeth Strunck ◽  
Gunter Vollmer
Keyword(s):  
Extracellular Matrix ◽  
Endometrial Adenocarcinoma ◽  
Tumor Development ◽  
Functional Differentiation ◽  
Cell Matrix ◽  
Integrin Β4 ◽  
The Matrix ◽  
And Function ◽  
Cell Matrix Interactions

The influence of extracellular matrix (ECM) on expression and function of integrins in carcinogenesis and differentiation is not well understood, but the importance of altered adhesion features for tumor development and progression is obvious. Integrins as versatile molecules are mainly responsible for mediating cell–matrix interactions and transmembrane signal transduction. They are capable of transducing outside-in signals from ECM components or conversely to organize the matrix by inside-out signaling. In the study presented here, we report that the reconstituted basement membrane, Matrigel™, which induces morphological and functional differentiation of the endometrial adenocarcinoma cell line HEC 1B(L), also regulates the expression of various forms of the integrin β4 subunit. Furthermore, we were able to identify full-length isoforms with and without an altered cytoplasmic domain as well as truncated forms. Our findings suggest a regulatory role of integrin β4 isoforms and fragments in the process of in vitro differentiation of HEC 1B(L).Key words: endometrium, tumor cells, differentiation, extracellular matrix, β4-integrin expression.

Scaffolds in tissue engineering of blood vessels

2010 ◽  
Vol 88 (9) ◽  
pp. 855-873 ◽  
Author(s):  
Divya Pankajakshan ◽  
Devendra K. Agrawal
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Blood Vessels ◽  
Vascular Tissue ◽  
Small Diameter ◽  
Biological Scaffolds ◽  
Hemodynamic Forces ◽  
Biodegradable Scaffolds

Tissue engineering of small diameter (<5 mm) blood vessels is a promising approach for developing viable alternatives to autologous vascular grafts. It involves in vitro seeding of cells onto a scaffold on which the cells attach, proliferate, and differentiate while secreting the components of extracellular matrix that are required for creating the tissue. The scaffold should provide the initial requisite mechanical strength to withstand in vivo hemodynamic forces until vascular smooth muscle cells and fibroblasts reinforce the extracellular matrix of the vessel wall. Hence, the choice of scaffold is crucial for providing guidance cues to the cells to behave in the required manner to produce tissues and organs of the desired shape and size. Several types of scaffolds have been used for the reconstruction of blood vessels. They can be broadly classified as biological scaffolds, decellularized matrices, and polymeric biodegradable scaffolds. This review focuses on the different types of scaffolds that have been designed, developed, and tested for tissue engineering of blood vessels, including use of stem cells in vascular tissue engineering.

Molecular regulation of cellular invasion— role of gelatinase A and TIMP-2

1996 ◽  
Vol 74 (6) ◽  
pp. 823-831 ◽  
Author(s):  
Anita E. Yu ◽  
Robert E. Hewitt ◽  
David E. Kleiner ◽  
William G. Stetler-Stevenson
Keyword(s):  
Extracellular Matrix ◽  
Matrix Metalloproteinases ◽  
Tissue Inhibitors Of Metalloproteinases ◽  
Gelatinase A ◽  
Cellular Mechanisms ◽  
Cell Matrix ◽  
Matrix Interactions ◽  
The Matrix ◽  
Cell Matrix Interactions

Extracellular matrix (ECM) turnover is an event that is tightly regulated. Much of the coordinate (physiological) or discoordinate (pathological) degradation of the ECM is catalyzed by a class of proteases known as the matrix metalloproteinases (MMPs) or matrixins. Matrixins are a family of homologous Zn atom dependent endopeptidases that are usually secreted from cells as inactive zymogens. Net degradative activity in the extracellular environment is regulated by specific activators and inhibitors. One member of the matrixin family, gelatinase A, is regulated differently from other MMPs, suggesting that it may play a unique role in cell–matrix interactions, including cell invasion. The conversion from the 72 kDa progelatinase A to the active 62 kDa species may be a key event in the acquisition of invasive potential. This discussion reviews some recent findings on the cellular mechanisms involved in progelatinase A activation and, in particular, the role of tissue inhibitor of matrix metalloproteinases-2 (TIMP-2) and transmembrane containing metalloproteinases (MT-MMP) in this process.Key words: tissue inhibitors of metalloproteinases, metalloproteinase, gelatinases, extracellular matrix, activation.

P0658MATRIX AND FLOW MODULATE GENE EXPRESSION IN A 3D VASCULARISED TUBULE MODEL

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Julie Williams ◽  
Sanlin Robinson ◽  
Babak Alaei ◽  
Kimberly Homan ◽  
Maryam Clausen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Extracellular Matrix ◽  
Impact Analysis ◽  
Cell Types ◽  
Drug Uptake ◽  
Shear Stresses ◽  
The Matrix ◽  
And Function

Abstract Background and Aims Questions abound regarding the translation of in vitro 2D cell culture systems to the human setting. This is especially true of the kidney in which there is a complex hierarchical structure and a multitude of cell types. While it is well accepted that extracellular matrix plays a large part in directing cellular physiology emerging research has highlighted the importance of shear stresses and flow rates too. To fully recapitulate the normal gene expression and function of a particular renal cell type how important is it to completely reconstitute their in vivo surroundings? Method To answer this question, we have cultured proximal tubular (PT) epithelial cells in a 3-dimensional channel embedded within an engineered extracellular matrix (ECM) under physiological flow that is colocalised with an adjacent channel lined with renal microvascular endothelial cells that mimic a peritubular capillary. Modifications to the system were made to allow up to 12 chips to be run in parallel in an easily handleable form. After a period of maturation under continuous flow, both cell types were harvested for RNAseq analyses. RNA expression data was compared with cells cultured under static 2-dimensional conditions on plastic or the engineered ECM. Additionally, the perfusion of glucose through this 3D vascularised PT model has been investigated in the presence and absence of known diabetes modulating agents. Results PCA of RNAseq data showed that a) static non-coated, b) static matrix-coated and c) flow matrix-coated conditions separated into 3 distinct groups, while cell co-culture had less impact. Analysis of transcriptomic signatures showed that many genes were modulated by the matrix with additional genes influenced under flow conditions. Several of these genes, classified as transporters, are of particular importance when using this model to assess drug uptake and safety implications. Co-culture regulated some interesting genes, but fewer than anticipated. Preliminary experiments are underway to monitor glucose uptake and transport between tubules under different conditions. Conclusion We have developed a medium throughput system in which matrix and flow modulate gene expression. This system can be used to study the physiology of molecular cross-talk between cells. Ongoing analysis will further consider relevance to human physiology.

The matrix secreted by 804G cells contains laminin-related components that participate in hemidesmosome assembly in vitro

1993 ◽  
Vol 105 (3) ◽  
pp. 753-764 ◽  
Author(s):  
M. Langhofer ◽  
S.B. Hopkinson ◽  
J.C. Jones
Keyword(s):  
Lectin Binding ◽  
Rabbit Antiserum ◽  
Epithelial Cell Line ◽  
Antigenic Relationship ◽  
Matrix Elements ◽  
Cell Matrix ◽  
The Matrix ◽  
Bona Fide ◽  
Functional Analyses

Hemidesmosomes are important adhesion devices found in epithelial cells. They connect the intermediate filament cytoskeleton network with components of the basement membrane zone. 804G cells are an unusual epithelial cell line, since they form bona fide hemidesmosomes when plated on glass or plastic. In this study we tested an hypothesis: that this ability is a consequence of an extracellular component produced by the 804G cells. As probes for our study we generated a rabbit antiserum (J18) and monoclonal antibodies against components of urea-solubilized 804G matrix. Antibodies in the J18 serum recognize major lectin-binding polypeptides of 150, 140 and 135 kDa in the 804G matrix. A monoclonal antibody (5C5) that shows reactivity with the 150 and 135 kDa polypeptides in western immunoblots immunoprecipitates all three molecular mass species, indicating that these polypeptides are part of a matrix complex. Moreover, one, at least, of these matrix elements is immunologically related to laminin, since J18 antibodies selected on fusion protein fragments of a newly characterized laminin variant, laminin B2t (Kallunki et al., J. Cell Biol., 119, 679–694, 1992), react with the 140 kDa polypeptide component of the 804G cell matrix. To undertake functional analyses of 804G matrix, cells of the human epidermal carcinoma line SCC12, which do not assemble bona fide hemidesmosomes in vitro, were cultured on 804G matrix for 24 h and then analysed by confocal immunofluorescence and electron microscopy. In SCC12 cells maintained on 804G cell matrix, hemidesmosomal antigens localize in a distinctive leopard spot pattern that mirrors the distribution of 804G matrix elements. Furthermore, ultrastructural analysis reveals that the 804G cell matrix supports the formation of ‘mature’ hemidesmosomes by SCC12 cells. Thus 804G cell matrix is a remarkable tool for hemidesmosome studies and it will now be of great importance to determine the exact composition of the 804G matrix, especially its structural and antigenic relationship to laminins.

Epithelial-derived TGF-β2 modulates basal and wound-healing subepithelial matrix homeostasis

2006 ◽  
Vol 291 (6) ◽  
pp. L1277-L1285 ◽  
Author(s):  
H. Garrett R. Thompson ◽  
Justin D. Mih ◽  
Tatiana B. Krasieva ◽  
Bruce J. Tromberg ◽  
Steven C. George
Keyword(s):  
Extracellular Matrix ◽  
Wound Healing ◽  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Transforming Growth Factor ◽  
Second Harmonic ◽  
Smooth Muscle Actin ◽  
Critical Role ◽  
The Matrix

The epithelium influences the mesenchyme during dynamic processes such as embryogenesis, wound healing, fibrosis, and carcinogenesis. Since transforming growth factor-β (TGF-β) modulates these processes, we hypothesized that epithelial-derived TGF-β also plays a critical role in maintaining the extracellular matrix at basal conditions. We utilized an in vitro model of the epithelial-mesenchymal trophic unit in the human airways to determine the role of epithelial-derived TGF-β in modulating the extracellular matrix under basal and wound-healing conditions. When differentiated at an air-liquid interface, the human bronchial epithelium produces active TGF-β2 at a concentration of 50–70 pg/ml, whereas TGF-β1 is undetectable. TGF-β2 increases two- to threefold following scrape injury in a dose-dependent fashion and significantly enhances both α-smooth muscle actin expression in the underlying collagen-embedded fibroblasts and secretion of tenascin-C into the matrix. Multiphoton microscopy demonstrates substantially enhanced second harmonic generation from fibrillar collagen in the matrix. Pretreatment of the matrix with either sirolimus (2.5 nM) or paclitaxel (10 nM) abolishes the increases in both TGF-β2 and second harmonic generation in response to epithelial injury. In the absence of the epithelium, exogenous active TGF-β2 (0–400 pg/ml) produces a biphasic response in the second harmonic signal with a minimum occurring at the epithelial-derived basal level. We conclude that epithelial-derived TGF-β2 is secreted in response to injury, significantly alters the bulk optical properties of the extracellular matrix, and its tight regulation may be required for normal collagen homeostasis.

scholarly journals Interaction of the Leucine-Rich Repeats of Polycystin-1 with Extracellular Matrix Proteins: Possible Role in Cell Proliferation

2002 ◽  
Vol 13 (1) ◽  
pp. 19-26
Author(s):  
Ashraf N. Malhas ◽  
Ramadan A. Abuknesha ◽  
Robert G. Price
Keyword(s):  
Extracellular Matrix ◽  
Cell Proliferation ◽  
Fusion Protein ◽  
Cyst Fluid ◽  
Suppression Effect ◽  
Cell Matrix ◽  
Membrane Bound ◽  
Autosomal Dominant Polycystic Kidney ◽  
Leucine Rich Repeats

ABSTRACT. Polycystin-1, the product of the PKD1 gene, is a membrane-bound multidomain protein with a unique structure and a molecular weight of ≈460 kD. The purpose of this study is to investigate the binding of the cystein-flanked leucine-rich repeats (LRR) of polycystin-1 to extracellular matrix (ECM) components. These interactions may play a role in normal renal development as well as the pathogenesis of autosomal-dominant polycystic kidney disease (ADPKD). In vitro assays were used to assess the binding of a fusion protein containing the LRR of polycystin-1 and that of affinity purified polycystin-1 to a number of ECM components. The results showed that the LRR modulate the binding of polycystin-1 to collagen I, fibronectin, laminin, and cyst fluid–derived laminin fragments. The addition of the LRR fusion protein to cells in culture resulted in a significant dose-dependant reduction in the rate of proliferation. Cyst fluid–derived laminin fragments had a stimulatory effect on cell proliferation, which was reversed by the LRR fusion protein. These results suggest that the LRR of polycystin-1 act as mediators of the polycystin-1 interaction with the ECM. The observed suppression effect of the LRR on cell proliferation suggests a functional role of the LRR-mediated polycystin-1 involvement in cell-matrix and cell-cell interactions. These interactions may result in the enhanced cell proliferation that is a characteristic feature of ADPKD.

scholarly journals Developing defined substrates for stem cell culture and differentiation

2018 ◽  
Vol 373 (1750) ◽  
pp. 20170230 ◽  
Author(s):  
Louise Hagbard ◽  
Katherine Cameron ◽  
Paul August ◽  
Christopher Penton ◽  
Malin Parmar ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Stem Cell ◽  
Cell Fate ◽  
Cell Types ◽  
Specific Cell ◽  
Biologically Relevant ◽  
Stem Cell Maintenance ◽  
Signalling Molecules ◽  
Cell Matrix

Over the past few decades, a variety of different reagents for stem cell maintenance and differentiation have been commercialized. These reagents share a common goal in facilitating the manufacture of products suitable for cell therapy while reducing the amount of non-defined components. Lessons from developmental biology have identified signalling molecules that can guide the differentiation process in vitro , but less attention has been paid to the extracellular matrix used. With the introduction of more biologically relevant and defined matrices, that better mimic specific cell niches, researchers now have powerful resources to fine-tune their in vitro differentiation systems, which may allow the manufacture of therapeutically relevant cell types. In this review article, we revisit the basics of the extracellular matrix, and explore the important role of the cell–matrix interaction. We focus on laminin proteins because they help to maintain pluripotency and drive cell fate specification. This article is part of the theme issue ‘Designer human tissue: coming to a lab near you’.

scholarly journals Perturbation of human endothelial cells by thrombin or PMA changes the reactivity of their extracellular matrix towards platelets.

1987 ◽  
Vol 104 (3) ◽  
pp. 697-704 ◽  
Author(s):  
P G de Groot ◽  
J H Reinders ◽  
J J Sixma
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Von Willebrand Factor ◽  
De Novo ◽  
The Matrix ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Adhesion Of Platelets ◽  
De Novo Protein Synthesis

In this study we have examined the influence of perturbation of endothelial cells on the amounts of fibronectin and von Willebrand factor in their extracellular matrix and the consequences of a changed composition of the matrix on platelet adhesion. For this purpose, we have used an in vitro perfusion system with which we can investigate the interactions of platelets in flowing blood with cultured endothelial cells and their extracellular matrix (Sakariassen, K. S., P. A. M. M. Aarts, P. G. de Groot, W. P. M. Houdgk, and J. J. Sixma, 1983, J. Lab. Clin Med. 102:522-535). Treatment of endothelial cells with 0.1-1.0 U/ml thrombin for 2 h increased the reactivity of the extracellular matrix, isolated after the thrombin treatment, towards platelets by approximately 50%. The increased reactivity did not depend on de novo protein synthesis but was inhibited by 3-deazaadenosine, an inhibitor of phospholipid methylation, which also inhibits the stimulus-induced instantaneous release of von Willebrand factor from endothelial cells. However, no changes in the amounts of von Willebrand factor and fibronectin in the matrix were detected. Thrombin may change the organization of the matrix proteins, not the composition. When endothelial cells were perturbed with the phorbol ester PMA or thrombin for 3 d, the adhesion of platelets to the extracellular matrix of treated cells was strongly impaired. This impairment coincided with a decrease in the amounts of von Willebrand factor and fibronectin present in the matrix. These results indicate that, after perturbation, endothelial cells regulate the composition of their matrix, and that this regulation has consequences for the adhesion of platelets.

scholarly journals Extracellular matrix-specific induction of elastogenic differentiation and maintenance of phenotypic stability in bovine ligament fibroblasts.

1984 ◽  
Vol 98 (5) ◽  
pp. 1804-1812 ◽  
Author(s):  
R P Mecham ◽  
J G Madaras ◽  
R M Senior
Keyword(s):  
Extracellular Matrix ◽  
Cell Layer ◽  
Late Gestation ◽  
Induced Differentiation ◽  
Continuous Contact ◽  
Cell Matrix ◽  
Matrix Cell ◽  
Undifferentiated Cells ◽  
The Matrix ◽  
Entire Cell

We studied the process of elastogenic differentiation in the bovine ligamentum nuchae to assess the mechanisms that regulate elastin gene expression during development. Undifferentiated ( nonelastin -producing) ligament cells from early gestation animals initiate elastin synthesis when grown on an extracellular matrix (ECM) substratum prepared from late gestation ligamentum nuchae. ECM from ligaments of fetal calves younger than the time when elastin production occurs spontaneously in situ (i.e., beginning the last developmental trimester at approximately 180 d of gestation) does not stimulate elastin production in undifferentiated cells. Matrix-induced differentiation requires direct cell matrix interaction, is dependent upon cell proliferation after cell-matrix contact, and can be blocked selectively by incorporation of bromodeoxyuridine into the DNA of undifferentiated cells before (but not after) contact with inducing matrix. Quantitative analysis of elastin synthesis in young cells after matrix-induced differentiation indicates that the entire cell population is competent to respond to the matrix inducer, and continued synthesis of elastin after young cells are removed from the ECM substratum indicates that the phenotypic transition to elastin synthesis is stable and heritable. Although ligament cells do not require continuous contact with ECM to express the elastin phenotype, elastin synthesis is increased substantially when elastin-producing cells are grown on ligament matrix, suggesting that elastogenic differentiation is stabilized by ECM. The matrix substratum was also found to alter the distribution of tropoelastin between the medium and matrix cell layer. When grown on tissue culture plastic, ligament cells secrete greater than 80% of newly synthesized tropoelastin into the culture medium. When cultured on ECM, however, 50-70% of the newly synthesized tropoelastin remains associated with the cell layer and is cross-linked to form insoluble elastin as shown by the incorporation of radiolabeled lysine into desmosine.

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