scholarly journals Topography-induced large-scale anti-parallel collective migration in vascular endothelium

2021 ◽  
Author(s):  
Claire Leclech ◽  
David Gonzalez-Rodriguez ◽  
Aur&eacutelien Villedieu ◽  
Th&eacutevy Lok ◽  
Anne-Marie D&eacuteplanche ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cell ◽  
Intact Cell ◽  
Cell Sheet ◽  
Cell Junctions ◽  
Periodic Pattern ◽  
Physical Factors ◽  
Collective Migration ◽  
Cell Assemblies ◽  
Collective Movement

Collective migration of vascular endothelial cells is central for embryonic development, angiogenesis, and wound closure. Although physical confinement of cell assemblies has been shown to elicit specific patterns of collective movement in various cell types, endothelial migration in vivo often occurs without confinement. Here we show that unconfined endothelial cell monolayers on microgrooved substrates that mimic the anisotropic organization of the extracellular matrix exhibit a new type of collective movement that takes the form of a periodic pattern of anti-parallel cell streams. We further establish that the development of these streams requires intact cell-cell junctions and that stream sizes are particularly sensitive to groove depth. Finally, we show that modeling the endothelial cell sheet as an active fluid with the microgrooves acting as constraints on cell orientation predicts the occurrence of the periodic anti-parallel cell streams as well as their lengths and widths. We posit that in unconfined cell assemblies, physical factors that constrain or bias cellular orientation such as anisotropic extracellular matrix cues or directed flow-derived shear forces dictate the pattern of collective cell movement.

scholarly journals PKM2 regulates endothelial cell junction dynamics and angiogenesis via ATP production

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jesús Gómez-Escudero ◽  
Cristina Clemente ◽  
Diego García-Weber ◽  
Rebeca Acín-Pérez ◽  
Jaime Millán ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Inflammatory Disease ◽  
Chronic Inflammatory Disease ◽  
Cell Junctions ◽  
Cell Junction ◽  
Collective Migration ◽  
Sprouting Angiogenesis ◽  
Cell Cell

Abstract Angiogenesis, the formation of new blood vessels from pre-existing ones, occurs in pathophysiological contexts such as wound healing, cancer, and chronic inflammatory disease. During sprouting angiogenesis, endothelial tip and stalk cells coordinately remodel their cell-cell junctions to allow collective migration and extension of the sprout while maintaining barrier integrity. All these processes require energy, and the predominant ATP generation route in endothelial cells is glycolysis. However, it remains unclear how ATP reaches the plasma membrane and intercellular junctions. In this study, we demonstrate that the glycolytic enzyme pyruvate kinase 2 (PKM2) is required for sprouting angiogenesis in vitro and in vivo through the regulation of endothelial cell-junction dynamics and collective migration. We show that PKM2-silencing decreases ATP required for proper VE-cadherin internalization/traffic at endothelial cell-cell junctions. Our study provides fresh insight into the role of ATP subcellular compartmentalization in endothelial cells during angiogenesis. Since manipulation of EC glycolysis constitutes a potential therapeutic intervention route, particularly in tumors and chronic inflammatory disease, these findings may help to refine the targeting of endothelial glycolytic activity in disease.

scholarly journals N-Isopropylacrylamide-co-glycidylmethacrylate as a Thermoresponsive Substrate for Corneal Endothelial Cell Sheet Engineering

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Bernadette K. Madathil ◽  
Pallickaveedu RajanAsari Anil Kumar ◽  
Thrikkovil Variyath Kumary
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cell ◽  
Cell Sheet ◽  
Corneal Endothelial Cell ◽  
Solution Temperature ◽  
Pcr Analysis ◽  
Cell Contact ◽  
Endothelial Keratoplasty ◽  
Matrix Deposition ◽  
Stimuli Responsive Polymers

Endothelial keratoplasty is a recent shift in the surgical treatment of corneal endothelial dystrophies, where the dysfunctional endothelium is replaced whilst retaining the unaffected corneal layers. To overcome the limitation of donor corneal shortage, alternative use of tissue engineered constructs is being researched. Tissue constructs with intact extracellular matrix are generated using stimuli responsive polymers. In this study we evaluated the feasibility of using the thermoresponsive poly(N-isopropylacrylamide-co-glycidylmethacrylate) polymer as a culture surface to harvest viable corneal endothelial cell sheets. Incubation below the lower critical solution temperature of the polymer allowed the detachment of the intact endothelial cell sheet. Phase contrast and scanning electron microscopy revealed the intact architecture, cobble stone morphology, and cell-to-cell contact in the retrieved cell sheet. Strong extracellular matrix deposition was also observed. The RT-PCR analysis confirmed functionally active endothelial cells in the cell sheet as evidenced by the positive expression of aquaporin 1, collagen IV, Na+-K+ATPase, and FLK-1. Na+-K+ATPase protein expression was also visualized by immunofluorescence staining. These results suggest that the in-house developed thermoresponsive culture dish is a suitable substrate for the generation of intact corneal endothelial cell sheet towards transplantation for endothelial keratoplasty.

scholarly journals Architecture of cell–cell junctions in situ reveals a mechanism for bacterial biofilm inhibition

2021 ◽  
Vol 118 (31) ◽  
pp. e2109940118
Author(s):  
Charlotte E. Melia ◽  
Jani R. Bolla ◽  
Stefan Katharios-Lanwermeyer ◽  
Daniel B. Mihaylov ◽  
Patrick C. Hoffmann ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Bacterial Infections ◽  
Intact Cell ◽  
Ion Beam ◽  
Cell Interactions ◽  
Bacterial Biofilm ◽  
Cell Junctions ◽  
Biofilm Inhibition ◽  
Cell Cell

Many bacteria, including the major human pathogen Pseudomonas aeruginosa, are naturally found in multicellular, antibiotic-tolerant biofilm communities, in which cells are embedded in an extracellular matrix of polymeric molecules. Cell–cell interactions within P. aeruginosa biofilms are mediated by CdrA, a large, membrane-associated adhesin present in the extracellular matrix of biofilms, regulated by the cytoplasmic concentration of cyclic diguanylate. Here, using electron cryotomography of focused ion beam–milled specimens, we report the architecture of CdrA molecules in the extracellular matrix of P. aeruginosa biofilms at intact cell–cell junctions. Combining our in situ observations at cell–cell junctions with biochemistry, native mass spectrometry, and cellular imaging, we demonstrate that CdrA forms an extended structure that projects from the outer membrane to tether cells together via polysaccharide binding partners. We go on to show the functional importance of CdrA using custom single-domain antibody (nanobody) binders. Nanobodies targeting the tip of functional cell-surface CdrA molecules could be used to inhibit bacterial biofilm formation or disrupt preexisting biofilms in conjunction with bactericidal antibiotics. These results reveal a functional mechanism for cell–cell interactions within bacterial biofilms and highlight the promise of using inhibitors targeting biofilm cell–cell junctions to prevent or treat problematic, chronic bacterial infections.

Thermo-Intelligent Surfaces for Cell Culture

2006 ◽  
Vol 53 ◽  
pp. 70-73
Author(s):  
Teruo Okano
Keyword(s):  
Intact Cell ◽  
Single Cells ◽  
Cell Sheet ◽  
Cell Junctions ◽  
Cell Sheets ◽  
Cell Sheet Engineering ◽  
Responsive Polymers ◽  
Temperature Responsive ◽  
Biodegradable Scaffolds ◽  
Tissue Reconstruction

In order to avoid several complications resulted from biodegradable scaffolds or single cell injection, we have developed “cell sheet engineering”. Our concept is novel tissue reconstruction not from single cells but from cell sheets. In order to prepare cell sheets, temperature-responsive culture dishes are utilized. Since temperature-responsive polymers are covalently grafted on the dishes, various types of cells adhere and proliferate on them at 37°C, but are spontaneously detached only by reducing temperature below 32°C without any need for proteolytic enzyme. All the confluent cells are noninvasively harvested as a single contiguous cell sheets with intact cell-cell junctions and deposited extracellular matrix. We have utilized these harvested cell sheets for various tissue reconstructions including ocular surfaces, periodontal ligament, cardiac patches as well as bladder.

scholarly journals Architecture of cell-cell junctions in situ reveals a mechanism for bacterial biofilm inhibition

2021 ◽  
Author(s):  
Charlotte E. Melia ◽  
Jani R. Bolla ◽  
Stefan Katharios-Lanwermeyer ◽  
Daniel B. Mihaylov ◽  
Patrick C. Hoffmann ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Bacterial Infections ◽  
Intact Cell ◽  
Ion Beam ◽  
Cell Interactions ◽  
Bacterial Biofilm ◽  
Cell Junctions ◽  
Biofilm Inhibition ◽  
Cell Cell

AbstractMany bacteria, including the major human pathogen Pseudomonas aeruginosa, are naturally found in multicellular, antibiotic-tolerant biofilm communities, where cells are embedded in an extracellular matrix of polymeric molecules. Cell-cell interactions within P. aeruginosa biofilms are mediated by CdrA, a large, membrane-associated adhesin present in the extracellular matrix of biofilms, regulated by the cytoplasmic concentration of cyclic diguanylate. Here, using electron cryotomography of focused-ion beam milled specimens, we report the architecture of CdrA molecules in the extracellular matrix of P. aeruginosa biofilms at intact cell-cell junctions. Combining our in situ observations at cell-cell junctions with biochemistry, native mass spectrometry and cellular imaging, we demonstrate that CdrA forms an extended structure that projects from the outer membrane to tether cells together via polysaccharide binding partners. We go on to show the functional importance of CdrA using custom single-domain antibody (nanobody) binders. Nanobodies targeting the tip of functional cell-surface CdrA molecules could be used to inhibit bacterial biofilm formation or disrupt pre-existing biofilms in conjunction with bactericidal antibiotics. These results reveal a functional mechanism for cell-cell interactions within bacterial biofilms and highlight the promise of using inhibitors targeting biofilm cell-cell junctions to prevent or treat problematic, chronic bacterial infections.

Naturally Produced Extracellular Matrix Is an Excellent Substrate for Canine Endothelial Cell Proliferation and Resistance to Shear Stress on PTFE Vascular Grafts

1997 ◽  
Vol 78 (05) ◽  
pp. 1392-1398 ◽  
Author(s):  
A Schneider ◽  
M Chandra ◽  
G Lazarovici ◽  
I Vlodavsky ◽  
G Merin ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Shear Stress ◽  
Endothelial Cell ◽  
Cell Attachment ◽  
Thrombus Formation ◽  
Endothelial Cell Proliferation ◽  
Ptfe Graft ◽  
Vascular Prostheses ◽  
Endothelial Cell Attachment

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.

scholarly journals Enhanced Piezoelectric Fibered Extracellular Matrix to Promote Cardiomyocyte Maturation and Tissue Formation: A 3D Computational Model

Biology ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 135
Author(s):  
Pau Urdeitx ◽  
Mohamed H. Doweidar
Keyword(s):  
Extracellular Matrix ◽  
Cell Migration ◽  
Computational Models ◽  
Cell Junctions ◽  
Tissue Formation ◽  
Cardiac Muscle Cells ◽  
Cell Processes ◽  
Electrical Stimuli ◽  
Cell Cell

Mechanical and electrical stimuli play a key role in tissue formation, guiding cell processes such as cell migration, differentiation, maturation, and apoptosis. Monitoring and controlling these stimuli on in vitro experiments is not straightforward due to the coupling of these different stimuli. In addition, active and reciprocal cell–cell and cell–extracellular matrix interactions are essential to be considered during formation of complex tissue such as myocardial tissue. In this sense, computational models can offer new perspectives and key information on the cell microenvironment. Thus, we present a new computational 3D model, based on the Finite Element Method, where a complex extracellular matrix with piezoelectric properties interacts with cardiac muscle cells during the first steps of tissue formation. This model includes collective behavior and cell processes such as cell migration, maturation, differentiation, proliferation, and apoptosis. The model has employed to study the initial stages of in vitro cardiac aggregate formation, considering cell–cell junctions, under different extracellular matrix configurations. Three different cases have been purposed to evaluate cell behavior in fibered, mechanically stimulated fibered, and mechanically stimulated piezoelectric fibered extra-cellular matrix. In this last case, the cells are guided by the coupling of mechanical and electrical stimuli. Accordingly, the obtained results show the formation of more elongated groups and enhancement in cell proliferation.

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