Cell–Matrix Entanglement and Mechanical Anchorage of Fibroblasts in Three-dimensional Collagen Matrices

Fibroblast-3D collagen matrix culture provides a physiologically relevant model to study cell–matrix interactions. In tissues, fibroblasts are phagocytic cells, and in culture, they have been shown to ingest both fibronectin and collagen-coated latex particles. Compared with cells on collagen-coated coverslips, phagocytosis of fibronectin-coated beads by fibroblasts in collagen matrices was found to be reduced. This decrease could not be explained by integrin reorganization, tight binding of fibronectin beads to the collagen matrix, or differences in overall bead binding to the cells. Rather, entanglement of cellular dendritic extensions with collagen fibrils seemed to interfere with the ability of the extensions to interact with the beads. Moreover, once these extensions became entangled in the matrix, cells developed an integrin-independent component of adhesion. We suggest that cell–matrix entanglement represents a novel mechanism of cell anchorage that uniquely depends on the three-dimensional character of the matrix.

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Integrated computational and experimental pipeline for quantifying local cell–matrix interactions

Scientific Reports ◽

10.1038/s41598-021-95935-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Hugh Xiao ◽

Ryan Y. Nguyen ◽

Ryan LaRanger ◽

Erica L. Herzog ◽

Michael Mak

Keyword(s):

Collagen Gel ◽

Collagen Matrix ◽

Cellular Level ◽

Lung Fibroblasts ◽

Cellular Interactions ◽

Cell Matrix ◽

Matrix Interactions ◽

3D Collagen ◽

Local Cell ◽

Cell Matrix Interactions

AbstractCellular interactions with the extracellular matrix (ECM) play a key role in modulating biological processes. While studies have identified key molecular factors of these interactions, the mechanical regulation associated with these interactions is not well characterized. To address this, we present an image analysis platform to analyze time-dependent dynamics observed in lung fibroblasts embedded in a 3D collagen matrix. Combining drug studies with quantitative analysis of cell–matrix interactions, our results are able to provide cellular level quantitative insights for mechanical and biophysical phenomena relevant to cell-ECM interactions. This system overall represents an initial pipeline for understanding cell mechanics in a 3D collagen gel and their implications in a physiologically relevant context.

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Modulation of Fibroblast Morphology and Adhesion during Collagen Matrix Remodeling

Molecular Biology of the Cell ◽

10.1091/mbc.e02-05-0291 ◽

2002 ◽

Vol 13 (11) ◽

pp. 3915-3929 ◽

Cited By ~ 168

Author(s):

Elisa Tamariz ◽

Frederick Grinnell

Keyword(s):

Wound Repair ◽

Three Dimensional ◽

Rho Kinase ◽

Focal Adhesions ◽

Collagen Matrix ◽

Collagen Fibrils ◽

Matrix Remodeling ◽

Cell Matrix ◽

Matrix Interactions ◽

Cell Matrix Interactions

When fibroblasts are placed within a three-dimensional collagen matrix, cell locomotion results in translocation of the flexible collagen fibrils of the matrix, a remodeling process that has been implicated in matrix morphogenesis during development and wound repair. In the current experiments, we studied formation and maturation of cell–matrix interactions under conditions in which we could distinguish local from global matrix remodeling. Local remodeling was measured by the movement of collagen-embedded beads towards the cells. Global remodeling was measured by matrix contraction. Our observations show that no direct relationship occurs between protrusion and retraction of cell extensions and collagen matrix remodeling. As fibroblasts globally remodel the collagen matrix, however, their overall morphology changes from dendritic to stellate/bipolar, and cell–matrix interactions mature from punctate to focal adhesion organization. The less well organized sites of cell–matrix interaction are sufficient for translocating collagen fibrils, and focal adhesions only form after a high degree of global remodeling occurs in the presence of growth factors. Rho kinase activity is required for maturation of fibroblast morphology and formation of focal adhesions but not for translocation of collagen fibrils.

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A computational framework for modeling cell–matrix interactions in soft biological tissues

Biomechanics and Modeling in Mechanobiology ◽

10.1007/s10237-021-01480-2 ◽

2021 ◽

Author(s):

Jonas F. Eichinger ◽

Maximilian J. Grill ◽

Iman Davoodi Kermani ◽

Roland C. Aydin ◽

Wolfgang A. Wall ◽

...

Keyword(s):

Soft Tissues ◽

Three Dimensional ◽

Biological Tissues ◽

Computational Framework ◽

Cell Matrix ◽

Physiological Processes ◽

Matrix Interactions ◽

Mechanical Homeostasis ◽

Cell Matrix Interactions ◽

Short Time

AbstractLiving soft tissues appear to promote the development and maintenance of a preferred mechanical state within a defined tolerance around a so-called set point. This phenomenon is often referred to as mechanical homeostasis. In contradiction to the prominent role of mechanical homeostasis in various (patho)physiological processes, its underlying micromechanical mechanisms acting on the level of individual cells and fibers remain poorly understood, especially how these mechanisms on the microscale lead to what we macroscopically call mechanical homeostasis. Here, we present a novel computational framework based on the finite element method that is constructed bottom up, that is, it models key mechanobiological mechanisms such as actin cytoskeleton contraction and molecular clutch behavior of individual cells interacting with a reconstructed three-dimensional extracellular fiber matrix. The framework reproduces many experimental observations regarding mechanical homeostasis on short time scales (hours), in which the deposition and degradation of extracellular matrix can largely be neglected. This model can serve as a systematic tool for future in silico studies of the origin of the numerous still unexplained experimental observations about mechanical homeostasis.

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Molecular regulation of cellular invasion— role of gelatinase A and TIMP-2

Biochemistry and Cell Biology ◽

10.1139/o96-088 ◽

1996 ◽

Vol 74 (6) ◽

pp. 823-831 ◽

Cited By ~ 58

Author(s):

Anita E. Yu ◽

Robert E. Hewitt ◽

David E. Kleiner ◽

William G. Stetler-Stevenson

Keyword(s):

Extracellular Matrix ◽

Matrix Metalloproteinases ◽

Tissue Inhibitors Of Metalloproteinases ◽

Gelatinase A ◽

Cellular Mechanisms ◽

Cell Matrix ◽

Matrix Interactions ◽

The Matrix ◽

Cell Matrix Interactions

Extracellular matrix (ECM) turnover is an event that is tightly regulated. Much of the coordinate (physiological) or discoordinate (pathological) degradation of the ECM is catalyzed by a class of proteases known as the matrix metalloproteinases (MMPs) or matrixins. Matrixins are a family of homologous Zn atom dependent endopeptidases that are usually secreted from cells as inactive zymogens. Net degradative activity in the extracellular environment is regulated by specific activators and inhibitors. One member of the matrixin family, gelatinase A, is regulated differently from other MMPs, suggesting that it may play a unique role in cell–matrix interactions, including cell invasion. The conversion from the 72 kDa progelatinase A to the active 62 kDa species may be a key event in the acquisition of invasive potential. This discussion reviews some recent findings on the cellular mechanisms involved in progelatinase A activation and, in particular, the role of tissue inhibitor of matrix metalloproteinases-2 (TIMP-2) and transmembrane containing metalloproteinases (MT-MMP) in this process.Key words: tissue inhibitors of metalloproteinases, metalloproteinase, gelatinases, extracellular matrix, activation.

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β1-Integrin Orients Epithelial Polarity via Rac1 and Laminin

Molecular Biology of the Cell ◽

10.1091/mbc.e04-05-0435 ◽

2005 ◽

Vol 16 (2) ◽

pp. 433-445 ◽

Cited By ~ 221

Author(s):

Wei Yu ◽

Anirban Datta ◽

Pascale Leroy ◽

Lucy Erin O'Brien ◽

Grace Mak ◽

...

Keyword(s):

Basement Membrane ◽

Mdck Cells ◽

Single Cells ◽

Three Dimensional ◽

Collagen Matrix ◽

Β1 Integrin ◽

Cell Matrix ◽

Β1 Integrins ◽

Normal Polarity ◽

Cell Matrix Interactions

Epithelial cells polarize and orient polarity in response to cell-cell and cell-matrix adhesion. Although there has been much recent progress in understanding the general polarizing machinery of epithelia, it is largely unclear how this machinery is controlled by the extracellular environment. To explore the signals from cell-matrix interactions that control orientation of cell polarity, we have used three-dimensional culture systems in which Madin-Darby canine kidney (MDCK) cells form polarized, lumen-containing structures. We show that interaction of collagen I with apical β1-integrins after collagen overlay of a polarized MDCK monolayer induces activation of Rac1, which is required for collagen overlay-induced tubulocyst formation. Cysts, comprised of a monolayer enclosing a central lumen, form after embedding single cells in collagen. In those cultures, addition of a β1-integrin function-blocking antibody to the collagen matrix gives rise to cysts that have defects in the organization of laminin into the basement membrane and have inverted polarity. Normal polarity is restored by either expression of activated Rac1, or the inclusion of excess laminin-1 (LN-1). Together, our results suggest a signaling pathway in which the activation of β1-integrins orients the apical pole of polarized cysts via a mechanism that requires Rac1 activation and laminin organization into the basement membrane.

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Imaging and Analysis of Cellular Locations in Three-Dimensional Tissue Models

Microscopy and Microanalysis ◽

10.1017/s1431927619000102 ◽

2019 ◽

Vol 25 (3) ◽

pp. 753-761 ◽

Cited By ~ 3

Author(s):

Warren Colomb ◽

Matthew Osmond ◽

Charles Durfee ◽

Melissa D. Krebs ◽

Susanta K. Sarkar

Keyword(s):

Three Dimensional ◽

Human Mesenchymal Stem Cells ◽

Basic Research ◽

Light Sheet ◽

Cell Matrix ◽

Matrix Interactions ◽

Cell Matrix Interactions ◽

Tissue Models ◽

Alginate Matrix

AbstractThe absence of quantitative in vitro cell–extracellular matrix models represents an important bottleneck for basic research and human health. Randomness of cellular distributions provides an opportunity for the development of a quantitative in vitro model. However, quantification of the randomness of random cell distributions is still lacking. In this paper, we have imaged cellular distributions in an alginate matrix using a multiview light sheet microscope and developed quantification metrics of randomness by modeling it as a Poisson process, a process that has constant probability of occurring in space or time. We imaged fluorescently labeled human mesenchymal stem cells embedded in an alginate matrix of thickness greater than 5 mm with $\sim\! {\rm 2}{\rm. 9} \pm {\rm 0}{\rm. 4}\,\mu {\rm m}$ axial resolution, the mean full width at half maximum of the axial intensity profiles of fluorescent particles. Simulated randomness agrees well with the experiments. Quantification of distributions and validation by simulations will enable quantitative study of cell–matrix interactions in tissue models.

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