scholarly journals Computational modelling of epidermal stratification highlights the importance of asymmetric cell division for predictable and robust layer formation

2014 ◽  
Vol 11 (99) ◽  
pp. 20140631 ◽  
Author(s):  
Alexander Gord ◽  
William R. Holmes ◽  
Xing Dai ◽  
Qing Nie
Keyword(s):  
Cell Adhesion ◽  
Cell Division ◽  
Asymmetric Cell Division ◽  
Three Dimensional ◽  
Interaction Strength ◽  
Computational Modelling ◽  
Protective Layer ◽  
The Body ◽  
Cell Interactions ◽  
Cell Cell

Skin is a complex organ tasked with, among other functions, protecting the body from the outside world. Its outermost protective layer, the epidermis, is comprised of multiple cell layers that are derived from a single-layered ectoderm during development. Using a new stochastic, multi-scale computational modelling framework, the anisotropic subcellular element method, we investigate the role of cell morphology and biophysical cell–cell interactions in the formation of this layered structure. This three-dimensional framework describes interactions between collections of hundreds to thousands of cells and (i) accounts for intracellular structure and morphology, (ii) easily incorporates complex cell–cell interactions and (iii) can be efficiently implemented on parallel architectures. We use this approach to construct a model of the developing epidermis that accounts for the internal polarity of ectodermal cells and their columnar morphology. Using this model, we show that cell detachment, which has been previously suggested to have a role in this process, leads to unpredictable, randomized stratification and that this cannot be abrogated by adjustment of cell–cell adhesion interaction strength. Polarized distribution of cell adhesion proteins, motivated by epithelial polarization, can however eliminate this detachment, and in conjunction with asymmetric cell division lead to robust and predictable development.

scholarly journals Mechanisms of endothelial cell coverage by pericytes: computational modelling of cell wrapping and in vitro experiments

2020 ◽  
Vol 17 (162) ◽  
pp. 20190739
Author(s):  
Kei Sugihara ◽  
Saori Sasaki ◽  
Akiyoshi Uemura ◽  
Satoru Kidoaki ◽  
Takashi Miura
Keyword(s):  
Cell Adhesion ◽  
Three Dimensional ◽  
Computational Modelling ◽  
Cellular Level ◽  
Cellular Potts Model ◽  
Contributing Factors ◽  
Modelling Framework ◽  
Cell Cell

Pericytes (PCs) wrap around endothelial cells (ECs) and perform diverse functions in physiological and pathological processes. Although molecular interactions between ECs and PCs have been extensively studied, the morphological processes at the cellular level and their underlying mechanisms have remained elusive. In this study, using a simple cellular Potts model, we explored the mechanisms for EC wrapping by PCs. Based on the observed in vitro cell wrapping in three-dimensional PC–EC coculture, the model identified four putative contributing factors: preferential adhesion of PCs to the extracellular matrix (ECM), strong cell–cell adhesion, PC surface softness and larger PC size. While cell–cell adhesion can contribute to the prevention of cell segregation and the degree of cell wrapping, it cannot determine the orientation of cell wrapping alone. While atomic force microscopy revealed that PCs have a larger Young’s modulus than ECs, the experimental analyses supported preferential ECM adhesion and size asymmetry. We also formulated the corresponding energy minimization problem and numerically solved this problem for specific cases. These results give biological insights into the role of PC–ECM adhesion in PC coverage. The modelling framework presented here should also be applicable to other cell wrapping phenomena observed in vivo .

Sertoli Cell Adhesion Molecules: Comparative Expression of Lselectin and Other Cams in Primary Cells And Immortalized Sertoli Cell Lines

1998 ◽  
Vol 4 (S2) ◽  
pp. 1068-1069
Author(s):  
Ann-Marie Broome ◽  
Clarke F. Millette
Keyword(s):  
Cell Adhesion ◽  
Adhesion Molecules ◽  
Sertoli Cell ◽  
Cell Adhesion Molecules ◽  
Three Dimensional ◽  
Cell Interactions ◽  
Seminiferous Epithelium ◽  
Testicular Development ◽  
And Function ◽  
Cell Cell

Cell adhesion and cell adhesion molecules (CAMs) play a crucial role in testicular development and function. The seminiferous epithelium, the functional unit of the testis, represents a three dimensional architecture of supporting Sertoli cells (SC), and developing germ cells (GC). The seminiferous epithelium, therefore, must be receptive not only to individual cell growth and differentiation, but also to cell-cell interactions. Morphologically distinct cell-cell interactions occur between SC and GC and also between SC.[1] In general, these junctions can be categorized into three types: adhesive, occluding, and gap junctions. The orientation and function of these junctions are interaction dependent. For example, desmosome-like junctions (spot desmosomes) are found between SC and GC. These junctions are present in the basal and intermediate compartments of the testis and serve to translocate developing GC. SC-SC interactions, like the zonula occludens (tight junction), function as vectorial mediators, maintaining the blood-testis barrier and SC polarity.

Approaches for Understanding Dynamic Cell Movements, Cell-Cell Interactions and Tissue Shaping During Embryogenesis of the Vertebrate Body Plan

1999 ◽  
Vol 5 (S2) ◽  
pp. 1078-1079
Author(s):  
G.C. Schoenwolf
Keyword(s):  
Descriptive Analysis ◽  
Molecular Genetic ◽  
Three Dimensional ◽  
Body Plan ◽  
The Body ◽  
Cell Interactions ◽  
Cell Movements ◽  
Dynamic Cell ◽  
Specialized Region ◽  
Cell Cell

The early vertebrate embryo develops a characteristic tube-within-a-tube body plan. This plan is realized through a series of cell movements and cell-cell interactions that collectively result in tissue shaping and the formation of the three-dimensional body plan. Tissue shaping is a highly choreographed process that is under the control of the organizer--a specialized region of the embryo that is both sufficient and required for formation of the body plan. Recent technical advances have greatly increased our understanding of the role of the organizer in vertebrate embryogenesis. Such advances include the use of new cellular, molecular, genetic, and embryological approaches.A hallmark of embryogenesis is its dynamic nature. Classically, embryos were studied in three major ways. 1) With morphological/descriptive analysis, initially involving histological procedures (stained whole mounts and serial sections cut in the three cardinal axes) and more recently electron microscopy.

scholarly journals Localization and site-specific cell–cell interactions of group 2 innate lymphoid cells

2021 ◽  
Author(s):  
Kiniwa Tsuyoshi ◽  
Kazuyo Moro
Keyword(s):  
Lipid Production ◽  
Allergic Diseases ◽  
Innate Lymphoid Cells ◽  
The Body ◽  
Cell Interactions ◽  
Lymphoid Cells ◽  
Specific Cell ◽  
Inflammatory Conditions ◽  
Group 2 ◽  
Cell Cell

Abstract Group 2 innate lymphoid cells (ILC2s) are novel lymphocytes discovered in 2010. Unlike T or B cells, ILC2s are activated nonspecifically by environmental factors and produce various cytokines, thus playing a role in tissue homeostasis, diseases including allergic diseases, and parasite elimination. ILC2s were first reported as cells abundantly present in fat-associated lymphoid clusters in adipose tissue. However, subsequent studies revealed their presence in various tissues throughout the body, acting as key players in tissue-specific diseases. Recent histologic analyses revealed that ILC2s are concentrated in specific regions in tissues, such as the lamina propria and perivascular regions, with their function being controlled by the surrounding cells, such as epithelial cells and other immune cells, via cytokine and lipid production or by cell–cell interactions through surface molecules. Especially, some stromal cells are identified as the niche cells for ILC2s, both in the steady state and under inflammatory conditions, through the production of IL-33 or extracellular-matrix factors. Additionally, peripheral neurons reportedly co-localize with ILC2s and alter their function directly through neurotransmitters. These findings suggest that the different localizations or different cell–cell interactions might affect the function of ILC2s. Furthermore, generally, ILC2s are thought to be tissue-resident cells; however, they occasionally migrate to other tissues and perform a new role; this supports the importance of the microenvironment for their function. We summarize here the current understanding of how the microenvironment controls ILC2 localization and function with the aim of promoting the development of novel diagnostic and therapeutic methods.

Cell Adhesion

2004 ◽  
Author(s):  
W. Mark Saltzman
Keyword(s):  
Extracellular Matrix ◽  
Cell Migration ◽  
Cell Adhesion ◽  
Cell Surface ◽  
Extracellular Space ◽  
Cell Aggregation ◽  
Solid Substrate ◽  
Cell Interactions ◽  
Phospholipid Bilayer ◽  
Cell Cell

The external surface of the cell consists of a phospholipid bilayer which carries a carbohydrate-rich coat called the glycocalyx; ionizable groups within the glycocalyx, such as sialic acid (N-acetyl neuraminate), contribute a net negative charge to the cell surface. Many of the carbohydrates that form the glycocalyx are bound to membrane-associated proteins. Each of these components— phospholipid bilayer, carbohydrate-rich coat, membrane-associated protein—has distinct physicochemical characteristics and is abundant. Plasma membranes contain ∼50% protein, ∼45% lipid, and ∼5% carbohydrate by weight. Therefore, each component influences cell interactions with the external environment in important ways. Cells can become attached to surfaces. The surface of interest may be geometrically complex (for example, the surface of another cell, a virus, a fiber, or an irregular object), but this chapter will focus on adhesion between a cell and a planar surface. The consequences of cell–cell adhesion are considered further in Chapter 8 (Cell Aggregation and Tissue Equivalents) and Chapter 9 (Tissue Barriers to Molecular and Cellular Transport). The consequences of cell–substrate adhesion are considered further in Chapter 7 (Cell Migration) and Chapter 12 (Cell Interactions with Polymers). Since the growth and function of many tissue-derived cells required attachment and spreading on a solid substrate, the events surrounding cell adhesion are fundamentally important. In addition, the strength of cell adhesion is an important determinant of the rate of cell migration, the kinetics of cell–cell aggregation, and the magnitude of tissue barriers to cell and molecule transport. Cell adhesion is therefore a major consideration in the development of methods and materials for cell delivery, tissue engineering, and tissue regeneration. The most stable and versatile mechanism for cell adhesion involves the specific association of cell surface glycoproteins, called receptors, and complementary molecules in the extracellular space, called ligands. Ligands may exist freely in the extracellular space, they may be associated with the extracellular matrix, or they may be attached to the surface of another cell. Cell–cell adhesion can occur by homophilic binding of identical receptors on different cells, by heterophilic binding of a receptor to a ligand expressed on the surface of a different cell, or by association of two receptors with an intermediate linker. Cell–matrix adhesion usually occurs by heterophilic binding of a receptor to a ligand attached to an insoluble element of the extracellular matrix.

scholarly journals Cadherins Promote Skeletal Muscle Differentiation in Three-dimensional Cultures

1997 ◽  
Vol 138 (6) ◽  
pp. 1323-1331 ◽  
Author(s):  
Ann Redfield ◽  
Marvin T. Nieman ◽  
Karen A. Knudsen
Keyword(s):  
Skeletal Muscle ◽  
Cell Adhesion ◽  
Three Dimensional ◽  
Muscle Differentiation ◽  
Skeletal Muscle Differentiation ◽  
Skeletal Myogenesis ◽  
Bhk Cells ◽  
Vitro Model ◽  
Cell Cell

The cell–cell adhesion molecule N-cadherin, with its associated catenins, is expressed by differentiating skeletal muscle and its precursors. Although N-cadherin's role in later events of skeletal myogenesis such as adhesion during myoblast fusion is well established, less is known about its role in earlier events such as commitment and differentiation. Using an in vitro model system, we have determined that N-cadherin– mediated adhesion enhances skeletal muscle differentiation in three-dimensional cell aggregates. We transfected the cadherin-negative BHK fibroblastlike cell line with N-cadherin. Expression of exogenous N-cadherin upregulated endogenous β-catenin and induced strong cell–cell adhesion. When BHK cells were cultured as three-dimensional aggregates, N-cadherin enhanced withdrawal from the cell cycle and stimulated differentiation into skeletal muscle as measured by increased expression of sarcomeric myosin and the 12/101 antigen. In contrast, N-cadherin did not stimulate differentiation of BHK cells in monolayer cultures. The effect of N-cadherin was not unique since E-cadherin also increased the level of sarcomeric myosin in BHK aggregates. However, a nonfunctional mutant N-cadherin that increased the level of β-catenin failed to promote skeletal muscle differentiation suggesting an adhesion-competent cadherin is required. Our results suggest that cadherin-mediated cell–cell interactions during embryogenesis can dramatically influence skeletal myogenesis.

scholarly journals Physical confinement signals regulate the organization of stem cells in three dimensions

2016 ◽  
Vol 13 (123) ◽  
pp. 20160613 ◽  
Author(s):  
Sebastian V. Hadjiantoniou ◽  
David Sean ◽  
Maxime Ignacio ◽  
Michel Godin ◽  
Gary W. Slater ◽  
...  
Keyword(s):  
Stem Cells ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Three Dimensional ◽  
Embryonic Stem ◽  
Cell Interactions ◽  
Three Dimensions ◽  
Cell Substrate ◽  
Cell Cell

During embryogenesis, the spherical inner cell mass (ICM) proliferates in the confined environment of a blastocyst. Embryonic stem cells (ESCs) are derived from the ICM, and mimicking embryogenesis in vitro , mouse ESCs (mESCs) are often cultured in hanging droplets. This promotes the formation of a spheroid as the cells sediment and aggregate owing to increased physical confinement and cell–cell interactions. In contrast, mESCs form two-dimensional monolayers on flat substrates and it remains unclear if the difference in organization is owing to a lack of physical confinement or increased cell–substrate versus cell–cell interactions. Employing microfabricated substrates, we demonstrate that a single geometric degree of physical confinement on a surface can also initiate spherogenesis. Experiment and computation reveal that a balance between cell–cell and cell–substrate interactions finely controls the morphology and organization of mESC aggregates. Physical confinement is thus an important regulatory cue in the three-dimensional organization and morphogenesis of developing cells.

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