scholarly journals A Novel Cell Vertex Model Formulation that Distinguishes the Strength of Contraction Forces and Adhesion at Cell Boundaries

2021 ◽  
Vol 9 ◽  
Author(s):  
Katsuhiko Sato ◽  
Daiki Umetsu
Keyword(s):  
Cell Sheet ◽  
Fruit Fly ◽  
Cell Boundary ◽  
Vertex Model ◽  
Cell Sheets ◽  
Vertex Models ◽  
Compartment Boundary ◽  
A Cell ◽  
External Forces ◽  
Strength Of Adhesion

The vertex model is a useful mathematical model to describe the dynamics of epithelial cell sheets. However, existing vertex models do not distinguish contraction forces on the cell boundary from adhesion between cells, employing a single parameter to express both. In this paper, we introduce the rest length of the cell boundary and its dynamics into the existing vertex model, giving a novel formulation of the model that treats separately the contraction force and the strength of adhesion between cells. We apply this vertex model to the phenomenon of compartment boundary in the fruit fly pupa, recapturing the observation that increasing the strength of adhesion between cells straightens the compartment boundary, even though contraction forces at cell boundaries remain unchanged. We also discuss possibilities of the novel vertex models by considering the stretching of a cell sheet by external forces.

scholarly journals Active inter-cellular forces in collective cell motility

2020 ◽  
Vol 17 (169) ◽  
pp. 20200312
Author(s):  
Guanming Zhang ◽  
Romain Mueller ◽  
Amin Doostmohammadi ◽  
Julia M. Yeomans
Keyword(s):  
Field Model ◽  
Cell Sheet ◽  
Phase Field Model ◽  
Cell Junctions ◽  
Sharp Transition ◽  
Cell Sheets ◽  
Persistent Random Walk ◽  
Confluent Cell ◽  
A Cell ◽  
Cellular Forces

The collective behaviour of confluent cell sheets is strongly influenced both by polar forces, arising through cytoskeletal propulsion, and by active inter-cellular forces, which are mediated by interactions across cell-cell junctions. We use a phase-field model to explore the interplay between these two contributions and compare the dynamics of a cell sheet when the polarity of the cells aligns to (i) their main axis of elongation, (ii) their velocity and (iii) when the polarity direction executes a persistent random walk. In all three cases, we observe a sharp transition from a jammed state (where cell rearrangements are strongly suppressed) to a liquid state (where the cells can move freely relative to each other) when either the polar or the inter-cellular forces are increased. In addition, for case (ii) only, we observe an additional dynamical state, flocking (solid or liquid), where the majority of the cells move in the same direction. The flocking state is seen for strong polar forces, but is destroyed as the strength of the inter-cellular activity is increased.

How Cell Shape Affects the Stresses in a Cell Sheet

2000 ◽  
Author(s):  
G. W. Brodland ◽  
Jim H. Veldhuis ◽  
Daniel I-Li Chen
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Cell Shape ◽  
Cell Sheet ◽  
Element Formulation ◽  
Analytical Mechanics ◽  
Cell Sheets ◽  
Average Cell ◽  
Real Cell ◽  
A Cell

Abstract Computer simulations and analytical mechanics are used to investigate the mechanics of cell sheets. The simulations are based on a recent finite element formulation [1] in which each cell is modeled using multiple finite elements, and cells can rearrange. Sheet stresses calculated using an analytical expression based on average cell shape are found to agree well with those calculated in the finite element simulations. This is an important step towards the development of constitutive equations to describe real cell sheets.

A Method for Electron Microscopic Study of Tissue Culture Cell Monolayers Grown in Tubes

1967 ◽  
Vol 25 ◽  
pp. 132-133
Author(s):  
R. Stephens ◽  
G. Schidlovsky ◽  
S. Kuzmic ◽  
P. Gaudreau
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Light Microscopy ◽  
Cell Sheet ◽  
Culture Cell ◽  
Tissue Culture Cell ◽  
Electron Microscopic ◽  
Cell Sheets ◽  
Morphological Alterations ◽  
Culture Cells

The usual method of scraping or trypsinization to detach tissue culture cell sheets from their glass substrate for further pelletization and processing for electron microscopy introduces objectionable morphological alterations. It is also impossible under these conditions to study a particular area or individual cell which have been preselected by light microscopy in the living state.Several schemes which obviate centrifugation and allow the embedding of nondetached tissue culture cells have been proposed. However, they all preserve only a small part of the cell sheet and make use of inverted gelatin capsules which are in this case difficult to handle.We have evolved and used over a period of several years a technique which allows the embedding of a complete cell sheet growing at the inner surface of a tissue culture roller tube. Observation of the same cell by light microscopy in the living and embedded states followed by electron microscopy is performed conveniently.

Abstract 020: Cell-sheet-based Bioengineered Human Cardiac Tissue Using Pluripotent Stem Cells For Heart Repair And Disease Models

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Katsuhisa Matsuura ◽  
Tatsuya Shimizu ◽  
Nobuhisa Hagiwara ◽  
Teruo Okano
Keyword(s):  
Cardiac Tissue ◽  
Subcutaneous Tissue ◽  
Cell Sheet ◽  
Three Dimensional ◽  
Embryoid Bodies ◽  
Cardiac Differentiation ◽  
Cardiac Cell ◽  
Cell Sheets ◽  
High Efficient ◽  
Human Cardiac Tissue

We have developed an original scaffold-free tissue engineering approach, “cell sheet engineering”, and this technology has been already applied to regenerative medicine of various organs including heart. As the bioengineered three-dimensional cardiac tissue is expected to not only function for repairing the broad injured heart but also to be the practicable heart tissue models, we have developed the cell sheet-based perfusable bioengineered three-dimensional cardiac tissue. Recently we have also developed the unique suspension cultivation system for the high-efficient cardiac differentiation of human iPS cells. Fourteen-day culture with the serial treatments of suitable growth factors and a small compound in this stirring system with the suitable dissolved oxygen concentration produced robust embryoid bodies that showed the spontaneous beating and were mainly composed of cardiomyocytes (~80%). When these differentiated cells were cultured on temperature-responsive culture dishes after the enzymatic dissociation, the spontaneous and synchronous beating was observed accompanied with the intracellular calcium influx all over the area even after cell were detached from culture dishes as cell sheets by lowering the culture temperature. The cardiac cell sheets were mainly composed of cardiomyocytes (~80%) and partially mural cells (~20%). Furthermore, extracellular action potential propagation was observed between cell sheets when two cardiac cell sheets were partially overlaid, and this propagation was inhibited by the treatment with some anti-arrhythmic drugs. When the triple layered cardiac tissue was transplanted onto the subcutaneous tissue of nude rats, the spontaneous pulsation was observed over 2 months and engrafted cardiomyocytes were vascularized with the host tissue-derived endothelial cells. These findings suggest that cardiac cell sheets formed by hiPSC-derived cardiomyocytes might have sufficient properties for the creation of thickened cardiac tissue. Now we are developing the vascularized thickened human cardiac tissue by the repeated layering of cardiac cell sheets on the artificial vascular bed in vitro.

scholarly journals Recent Advances in ROS-Responsive Cell Sheet Techniques for Tissue Engineering

2019 ◽  
Vol 20 (22) ◽  
pp. 5656 ◽  
Author(s):  
Min-Ah Koo ◽  
Mi Hee Lee ◽  
Jong-Chul Park
Keyword(s):  
Tissue Engineering ◽  
Cell Sheet ◽  
Cell Detachment ◽  
Oxygen Species ◽  
Cell Sheets ◽  
Cell Sheet Engineering ◽  
New Approach ◽  
Responsive Systems ◽  
Cell Based Therapy ◽  
Responsive Cell

Cell sheet engineering has evolved rapidly in recent years as a new approach for cell-based therapy. Cell sheet harvest technology is important for producing viable, transplantable cell sheets and applying them to tissue engineering. To date, most cell sheet studies use thermo-responsive systems to detach cell sheets. However, other approaches have been reported. This review provides the progress in cell sheet detachment techniques, particularly reactive oxygen species (ROS)-responsive strategies. Therefore, we present a comprehensive introduction to ROS, their application in regenerative medicine, and considerations on how to use ROS in cell detachment. The review also discusses current limitations and challenges for clarifying the mechanism of the ROS-responsive cell sheet detachment.

scholarly journals Mechanical bistability enabled by ectodermal compression facilitates Drosophila mesoderm invagination

2021 ◽  
Author(s):  
Hanqing Guo ◽  
Michael Swan ◽  
Shicheng Huang ◽  
Bing He
Keyword(s):  
Myosin Ii ◽  
Cell Sheet ◽  
Apical Surface ◽  
Apical Constriction ◽  
Out Of Plane ◽  
A Cell ◽  
Plane Compression ◽  
Contractile Forces ◽  
Tissue Relaxation ◽  
Muscle Myosin

Apical constriction driven by non-muscle myosin II (″myosin″) provides a well-conserved mechanism to mediate epithelial folding. It remains unclear how contractile forces near the apical surface of a cell sheet drive out-of-plane bending of the sheet and whether myosin contractility is required throughout folding. By optogenetic-mediated acute inhibition of myosin, we find that during Drosophila mesoderm invagination, myosin contractility is critical to prevent tissue relaxation during the early, ″priming″ stage of folding but is dispensable for the actual folding step after the tissue passes through a stereotyped transitional configuration, suggesting that the mesoderm is mechanically bistable during gastrulation. Combining computer modeling and experimental measurements, we show that the observed mechanical bistability arises from an in-plane compression from the surrounding ectoderm, which promotes mesoderm invagination by facilitating a buckling transition. Our results indicate that Drosophila mesoderm invagination requires a joint action of local apical constriction and global in-plane compression to trigger epithelial buckling.

scholarly journals Cell Sheets Restore Secretory Function in Wounded Mouse Submandibular Glands

Cells ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2645
Author(s):  
Harim T. dos Santos ◽  
Kyungsook Kim ◽  
Teruo Okano ◽  
Jean M. Camden ◽  
Gary A. Weisman ◽  
...  
Keyword(s):  
Cell Culture ◽  
Cell Sheet ◽  
Early Time ◽  
Cell Polarization ◽  
Cell Sheets ◽  
Long Term Stability ◽  
Tissue Integrity ◽  
Tissue Organization ◽  
Post Surgery ◽  
Salivary Gland Regeneration

Thermoresponsive cell culture plates release cells as confluent living sheets in response to small changes in temperature, with recovered cell sheets retaining functional extracellular matrix proteins and tight junctions, both of which indicate formation of intact and functional tissue. Our recent studies demonstrated that cell sheets are highly effective in promoting mouse submandibular gland (SMG) cell differentiation and recovering tissue integrity. However, these studies were performed only at early time points and extension of the observation period is needed to investigate duration of the cell sheets. Thus, the goal of this study was to demonstrate that treatment of wounded mouse SMG with cell sheets is capable of increasing salivary epithelial integrity over extended time periods. The results indicate that cell sheets promote tissue organization as early as eight days after transplantation and that these effects endure through Day 20. Furthermore, cell sheet transplantation in wounded SMG induces a significant time-dependent enhancement of cell polarization, differentiation and ion transporter expression. Finally, this treatment restored saliva quantity to pre-wounding levels at both eight and twenty days post-surgery and significantly improved saliva quality at twenty days post-surgery. These data indicate that cell sheets engineered with thermoresponsive cell culture plates are useful for salivary gland regeneration and provide evidence for the long-term stability of cell sheets, thereby offering a potential new therapeutic strategy for treating hyposalivation.

scholarly journals Stem cell-derived cell sheet transplantation for heart tissue repair in myocardial infarction

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Rui Guo ◽  
Masatoshi Morimatsu ◽  
Tian Feng ◽  
Feng Lan ◽  
Dehua Chang ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cell ◽  
Tissue Repair ◽  
Cardiac Tissue ◽  
Cell Sheet ◽  
Clinical Manifestations ◽  
Induced Pluripotent Stem Cell ◽  
Heart Tissue ◽  
Therapeutic Effects ◽  
Cell Sheets

AbstractStem cell-derived sheet engineering has been developed as the next-generation treatment for myocardial infarction (MI) and offers attractive advantages in comparison with direct stem cell transplantation and scaffold tissue engineering. Furthermore, induced pluripotent stem cell-derived cell sheets have been indicated to possess higher potential for MI therapy than other stem cell-derived sheets because of their capacity to form vascularized networks for fabricating thickened human cardiac tissue and their long-term therapeutic effects after transplantation in MI. To date, stem cell sheet transplantation has exhibited a dramatic role in attenuating cardiac dysfunction and improving clinical manifestations of heart failure in MI. In this review, we retrospectively summarized the current applications and strategy of stem cell-derived cell sheet technology for heart tissue repair in MI.

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