Time-Dependent Extracellular Matrix Organization and Secretion from Vascular Endothelial Cells due to Macromolecular Crowding

2014 ◽  
Vol 1623 ◽  
Author(s):  
Frances D. Liu ◽  
Adam S. Zeiger ◽  
Krystyn J. Van Vliet

ABSTRACTInteractions between biological cells and surrounding extracellular matrix (ECM) materials modulate many cell behaviors including adhesion and migration. One key example of this cellmatrix reciprocity is in the context of angiogenesis, the sprouting of new blood vessels from preexisting vasculature. Vascular endothelial cells (VECs) create and remodel the ECM during this process. In vivo, the surrounding fluid environment includes high concentrations of macromolecules, and is considered “crowded” in comparison to in vitro environments. Here, we quantified the amount and organization of collagen IV, a prominent ECM component of VECs, that was produced by these cells over four weeks in vitro in the presence or absence of macromolecular crowder (MMC) nanoparticles that approximated in vivo crowding. In the presence of MMCs, the amount and degree of alignment of collagen IV was greater. This ECM difference emerged within one week and was sustained for over four weeks. We explored the effect of initial cell density (cells/µm2) on this matrix production, to consider potential differences at a wound site versus an intact vessel. Moreover, we found the biophysical effect of MMCs to be unmodulated by secretions from an adjacent cell type in microvessels (pericytes). These results suggest that macromolecular crowding plays a direct role in remodeling the basement membrane, and that such crowding can be induced in vitro to more closely approximate the cell microenvironment.

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.


1996 ◽  
Vol 316 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Ralf BIRKENHÄGER ◽  
Bernard SCHNEPPE ◽  
Wolfgang RÖCKL ◽  
Jörg WILTING ◽  
Herbert A. WEICH ◽  
...  

Vascular endothilial growth factor (VEGF) and placenta growth factor (PIGF) are members of a dimeric-growth-factor family with angiogenic properties. VEGF is a highly potent and specific mitogen for endothelial cells, playing a vital role in angiogenesis in vivo. The role of PIGF is less clear. We expressed the monomeric splice forms VEGF-165, VEGF-121, PIGF-1 and PlGF-2 as unfused genes in Escherichia coli using the pCYTEXP expression system. In vitro dimerization experiments revealed that both homo- and hetero-dimers can be formed from these monomeric proteins. The dimers were tested for their ability to promote capillary growth in vivo and stimulate DNA synthesis in cultured human vascular endothelial cells. Heterodimers comprising different VEGF splice forms, or combinations of VEGF/PlGF splice forms, showed mitogenic activity. The results demonstrate that four different heterodimeric growth factors are likely to have as yet uncharacterized functions in vivo.


Blood ◽  
2010 ◽  
Vol 115 (20) ◽  
pp. 4130-4137 ◽  
Author(s):  
Jinmin Gao ◽  
Lei Sun ◽  
Lihong Huo ◽  
Min Liu ◽  
Dengwen Li ◽  
...  

Cylindromatosis (CYLD) is a deubiquitinase that was initially identified as a tumor suppressor and has recently been implicated in diverse normal physiologic processes. In this study, we have investigated the involvement of CYLD in angiogenesis, the formation of new blood vessels from preexisting ones. We find that knockdown of CYLD expression significantly impairs angiogenesis in vitro in both matrigel-based tube formation assay and collagen-based 3-dimensional capillary sprouting assay. Disruption of CYLD also remarkably inhibits angiogenic response in vivo, as evidenced by diminished blood vessel growth into the angioreactors implanted in mice. Mechanistic studies show that CYLD regulates angiogenesis by mediating the spreading and migration of vascular endothelial cells. Silencing of CYLD dramatically decreases microtubule dynamics in endothelial cells and inhibits endothelial cell migration by blocking the polarization process. Furthermore, we identify Rac1 activation as an important factor contributing to the action of CYLD in regulating endothelial cell migration and angiogenesis. Our findings thus uncover a previously unrecognized role for CYLD in the angiogenic process and provide a novel mechanism for Rac1 activation during endothelial cell migration and angiogenesis.


Author(s):  
LeShana SaintJean ◽  
H.S. Baldwin

The endocardium represents a distinct population of endothelial cells that arises during the initiation of heart development. Endocardial cells can easily be distinguished from most of the other cardiac cell types. However, endocardial and vascular endothelial cells contain a similar genetic profile that limits the ability to study each group independently. Despite these limitations, tremendous progress has been made in identifying the different roles of endocardial cells throughout heart development. Initial studies focused on the origin of endocardial cells and their role in valvulogenesis, trabeculation, and formation of the ventricular and atrial septum. With the advancement of microscopy and the availability of endocardial specific reporter models (in vitro and in vivo) we have obtained more insight into the molecular, structural, and functional complexity of the endocardium. Additional studies have demonstrated how the endocardium is also involved in the development of coronary vessels within the compact myocardium and in heart regeneration.


2017 ◽  
Vol 38 (5) ◽  
pp. 3153-3159 ◽  
Author(s):  
Xinwen Wang ◽  
Weifeng Xu ◽  
Shenglin Wang ◽  
Feqiang Yu ◽  
Jinyi Feng ◽  
...  

2012 ◽  
Vol 302 (4) ◽  
pp. H983-H991 ◽  
Author(s):  
Ji Zhang ◽  
Morton H. Friedman

The adaptation of vascular endothelial cells to shear stress alteration induced by global hemodynamic changes, such as those accompanying exercise or digestion, is an essential component of normal endothelial physiology in vivo. An understanding of the transient regulation of endothelial phenotype during adaptation to changes in mural shear will advance our understanding of endothelial biology and may yield new insights into the mechanism of atherogenesis. In this study, we characterized the adaptive response of arterial endothelial cells to an acute increase in shear stress magnitude in well-defined in vitro settings. Porcine endothelial cells were preconditioned by a basal level shear stress of 15 ± 15 dyn/cm2 at 1 Hz for 24 h, after which an acute increase in shear stress to 30 ± 15 dyn/cm2 was applied. Endothelial permeability nearly doubled after 40-min exposure to the elevated shear stress and then decreased gradually. Transcriptomics studies using microarray techniques identified 86 genes that were sensitive to the elevated shear. The acute increase in shear stress promoted the expression of a group of anti-inflammatory and antioxidative genes. The adaptive response of the global gene expression profile is triphasic, consisting of an induction period, an early adaptive response (ca. 45 min) and a late remodeling response. Our results suggest that endothelial cells exhibit a specific phenotype during the adaptive response to changes in shear stress; this phenotype is different than that of fully adapted endothelial cells.


Author(s):  
Cheng-Jen Chang ◽  
Chung-Ho Sun ◽  
Lih-Huei L. Liaw ◽  
Michael W. Berns ◽  
J. Stuart Nelson

Development ◽  
1995 ◽  
Vol 121 (4) ◽  
pp. 1089-1098 ◽  
Author(s):  
T.M. Schlaeger ◽  
Y. Qin ◽  
Y. Fujiwara ◽  
J. Magram ◽  
T.N. Sato

Vascular endothelial cells play essential roles in the function and development of the cardiovascular system. However, due to the lack of lineage-specific markers suitable for molecular and biochemical analyses, very little is known about the molecular mechanisms that regulate endothelial cell differentiation. We report the first vascular endothelial cell lineage-specific (including angioblastic precursor cells) 1.2 kb promoter in transgenic mice. Moreover, deletion analysis of this promoter region in transgenic embryos revealed multiple elements that are required for the maximum endothelial cell lineage-specific expression. This is a powerful molecular tool that will enable us to identify factors and cellular signals essential for the establishment of vascular endothelial cell lineage. It will also allow us to deliver genes specifically into this cell type in vivo to test specifically molecules that have been implicated in cardiovascular development. Furthermore, we have established embryonic stem (ES) cells from the blastocysts of the transgenic mouse that carry the 1.2 kb promoter-LacZ reporter transgene. These ES cells were able to differentiate in vitro to form cystic embryoid bodies (CEB) that contain endothelial cells determined by PECAM immunohistochemistry. However, these in vitro differentiated endothelial cells did not express the LacZ reporter gene. This indicates the lack of factors and/or cellular interactions which are required to induce the expression of the reporter gene mediated by this 1.2 kb promoter in this in vitro differentiation system. Thus this system will allow us to screen for the putative inducers that exist in vivo but not in vitro. These putative inducers are presumably important for in vivo differentiation of vascular endothelial cells.


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