scholarly journals Extracellular matrix stiffness modulates VEGF calcium signaling in endothelial cells: individual cell and population analysis

2015 ◽  
Vol 7 (9) ◽  
pp. 1011-1025 ◽  
Author(s):  
Kelsey E. Derricks ◽  
Vickery Trinkaus-Randall ◽  
Matthew A. Nugent

Endothelial cell responses to VEGF are heterogeneous and vary with ECM stiffness. We analyzed individual cell responses to VEGF as a function of substrate stiffness to identify unique clusters of cell signaling dynamics.

1997 ◽  
Vol 78 (05) ◽  
pp. 1392-1398 ◽  
Author(s):  
A Schneider ◽  
M Chandra ◽  
G Lazarovici ◽  
I Vlodavsky ◽  
G Merin ◽  
...  

SummaryPurpose: Successful development of a vascular prosthesis lined with endothelial cells (EC) may depend on the ability of the attached cells to resist shear forces after implantation. The present study was designed to investigate EC detachment from extracellular matrix (ECM) precoated vascular prostheses, caused by shear stress in vitro and to test the performance of these grafts in vivo. Methods: Bovine aortic endothelial cells were seeded inside untreated polytetrafluoro-ethylene (PTFE) vascular graft (10 X 0.6 cm), PTFE graft precoated with fibronectin (FN), or PTFE precoated with FN and a naturally produced ECM (106 cells/graft). Sixteen hours after seeding the medium was replaced and unattached cells counted. The strength of endothelial cell attachment was evaluated by subjecting the grafts to a physiologic shear stress of 15 dynes/cm2 for 1 h. The detached cells were collected and quantitated. PTFE or EC preseeded ECM coated grafts were implanted in the common carotid arteries of dogs. Results: While little or no differences were found in the extent of endothelial cell attachment to the various grafts (79%, 87% and 94% of the cells attached to PTFE, FN precoated PTFE, or FN+ECM precoated PTFE, respectively), the number of cells retained after a shear stress was significanly increased on ECM coated PTFE (20%, 54% and 85% on PTFE, FN coated PTFE, and FN+ECM coated PTFE, respectively, p <0.01). Implantation experiments in dogs revealed a significant increase in EC coverage and a reduced incidence of thrombus formation on ECM coated grafts that were seeded with autologous saphenous vein endothelial cells prior to implantation. Conclusion: ECM coating significantly increased the strength of endothelial cell attachment to vascular prostheses subjected to shear stress. The presence of adhesive macromolecules and potent endothelial cell growth promoting factors may render the ECM a promising substrate for vascular prostheses.


2001 ◽  
Vol 114 (5) ◽  
pp. 917-930 ◽  
Author(s):  
G.E. Davis ◽  
K.A. Pintar ◽  
Allen, R. Salazar ◽  
S.A. Maxwell

Here, we describe a new function for plasmin and matrix metalloproteinases (MMPs), which is to regulate the regression of capillary tubes in three-dimensional extracellular matrix environments. Using a well-described capillary morphogenesis system in three-dimensional collagen matrices, a new model of capillary regression has been established by adding plasminogen to the culture medium. Plasminogen is converted to plasmin by endothelial cell plasminogen activators which then induces matrix metalloproteinase-dependent collagen gel contraction and capillary regression. Plasminogen addition results in activation of MMP-1 and MMP-9, which then results in collagen proteolysis followed by capillary regression. The endothelial cells undergo apoptosis following gel contraction as detected by flow cytometric analysis as well as by detectable caspase-3 cleavage and caspase-dependent cleavage of the actin cytoskeletal regulatory protein, gelsolin. In addition, directly correlating with the contraction response, tyrosine phosphorylation of p130cas, an adapter protein in the focal adhesion complex, is observed followed by disappearance of the protein. Proteinase inhibitors that block MMPs (TIMP-1 or TIMP-2), plasminogen activators (PAI-1) or plasmin (aprotinin) completely block the gel contraction and regression process. In addition, chemical inhibitors of MMPs that block capillary regression also block MMP-1 and MMP-9 activation suggesting that a key element in this regression response is the molecular control of MMP activation by endothelial cells. Blocking antibodies directed to MMP-1 or MMP-9 interfere with capillary regression while blocking antibodies directed to PAI-1 accelerate capillary regression suggesting that endogenous synthesis of PAI-1 negatively regulates this process. These data present a novel system to study a new mechanism that may regulate regression of capillary tubes, namely, plasmin and MMP-mediated degradation of extracellular matrix.


2018 ◽  
Vol 10 (422) ◽  
pp. eaao0475 ◽  
Author(s):  
Marsha C. Lampi ◽  
Cynthia A. Reinhart-King

Tissues stiffen during aging and during the pathological progression of cancer, fibrosis, and cardiovascular disease. Extracellular matrix stiffness is emerging as a prominent mechanical cue that precedes disease and drives its progression by altering cellular behaviors. Targeting extracellular matrix mechanics, by preventing or reversing tissue stiffening or interrupting the cellular response, is a therapeutic approach with clinical potential. Major drivers of changes to the mechanical properties of the extracellular matrix include phenotypically converted myofibroblasts, transforming growth factor β (TGFβ), and matrix cross-linking. Potential pharmacological interventions to overcome extracellular matrix stiffening are emerging clinically. Aside from targeting stiffening directly, alternative approaches to mitigate the effects of increased matrix stiffness aim to identify and inhibit the downstream cellular response to matrix stiffness. Therapeutic interventions that target tissue stiffening are discussed in the context of their limitations, preclinical drug development efforts, and clinical trials.


1987 ◽  
Author(s):  
J H Reinders ◽  
C L Verweii ◽  
J A V Mourlk ◽  
Ph G de Groot

Endothelial cells, cultured from human umbilical veins, synthesize von Willebrand Factor (vWF), that is stored by the cells in Weibel-Palade bodies, secreted into the medium and incorporated into the extracellular matrix underneath the cells. We have studied the influence of perturbation by phorbol esters and thrombin on the cellular distribution of vWF. Short-term (< 1 hour) treatment of endothelial cells with phorbol ester PMA or thrombin resulted in the release of cellular stored vWF. Long-term treatment with perturbants evoked a distinct change in the endothelial cell distribution of vWF, evident 24 to 48 hours after exposure. While the contents of the vWF storage vesicles were gradually restored within 48 hours, enhanced amounts of vWF were secreted into the medium. However, PMA did not increase the endothelial cell contents of mRNA encoding for vWF. The number as well as the size of vWF storage granules in the cells increased after exposure to perturbants. The perturbed cells responded to stimuli in releasing stored vWF, the amounts secreted were even greater than those in control cells. The extracellular matrix lost its vWF contents as the result of PMA or thrombin treatment, by blocking deposition of vWF in the matrix, not by enhancing degradation of matrix vWF. In perfusion experiments, the adhesion of washed platelets onto the isolated matrix of perturbed cells was considerable less than that in controls. Addition of vWF to the perfusate overcame this impairment. Thus, perturbation of endothelial cells changes the cellular distribution of vWF.Supported in part by ZWO grants 13-30-31 and 13-90-91 and Netherlands Heart Foundation grant 28.004.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Takahiro Ebata ◽  
Hiroaki Hirata ◽  
Keiko Kawauchi

Mechanical microenvironments, such as extracellular matrix stiffness and strain, have crucial roles in cancer progression. Cells sense their microenvironments with mechanosensing biomolecules, which is accompanied by the modulation of actin cytoskeleton structures, and the signals are subsequently transduced downstream as biochemical signals. The tumor suppressors p53 and retinoblastoma protein (Rb) are known to prevent cancer progression. The p53 and Rb signaling pathways are disrupted in many types of cancers. Here, we review recent findings about the roles of these tumor suppressors in the regulation of mechanosensing biomolecules and the actin cytoskeleton. We further discuss how dysfunction in the p53- and/or Rb-mediated mechanosignaling pathways is potentially involved in cancer progression. These pathways might provide good targets for developing anticancer therapies.


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