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Lorat Y, Fleckenstein J, Görlinger P, Rübe C, Rübe CE. Assessment of DNA damage by 53PB1 and pKu70 detection in peripheral blood lymphocytes by immunofluorescence and high-resolution transmission electron microscopy. Strahlenther Onkol 2020; 196:821-833. [PMID: 32006067 PMCID: PMC7449954 DOI: 10.1007/s00066-020-01576-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 01/07/2020] [Indexed: 11/29/2022]
Abstract
Purpose 53BP1 foci detection in peripheral blood lymphocytes (PBLs) by immunofluorescence microscopy (IFM) is a sensitive and quantifiable DNA double-strand break (DSB) marker. In addition, high-resolution transmission electron microscopy (TEM) with immunogold labeling of 53BP1 and DSB-bound phosphorylated Ku70 (pKu70) can be used to determine the progression of the DNA repair process. To establish this TEM method in the PBLs of patients with cancer, we analyzed and characterized whether different modes of irradiation influence the formation of DSBs, and whether accompanying chemotherapy influences DSB formation. Methods We obtained 86 blood samples before and 0.1, 0.5, and 24 h after irradiation from patients (n = 9) with head and neck or rectal cancers receiving radiotherapy (RT; n = 4) or radiochemotherapy (RCT; n = 5). 53BP1 foci were quantified by IFM. In addition, TEM was used to quantify gold-labelled pKu70 dimers and 53BP1 clusters within euchromatin and heterochromatin of PBLs. Results IFM analyses showed that during radiation therapy, persistent 53BP1 foci in PBLs accumulated with increasing numbers of administered RT fractions. This 53BP1 foci accumulation was not influenced by the irradiation technique applied (3D conformal radiotherapy versus intensity-modulated radiotherapy), dose intensity per fraction, number of irradiation fields, or isodose volume. However, more 53BP1 foci were detected in PBLs of patients treated with accompanying chemotherapy. TEM analyses showed that DSBs, indicated by pKu70, were present for longer periods in PBLs of RCT patients than in PBLs of RT only patients. Moreover, not every residual 53BP1 focus was equivalent to a remaining DSB, since pKu70 was not present at every damage site. Persistent 53BP1 clusters, visualized by TEM, without colocalizing pKu70 likely indicate chromatin alterations after repair completion or, possibly, defective repair. Conclusion IFM 53BP1 foci analyses alone are not adequate to determine individual repair capacity after irradiation of PBLs, as a DSB may be indicated by a 53BP1 focus but not every 53BP1 focus represents a DSB. Electronic supplementary material The online version of this article (10.1007/s00066-020-01576-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yvonne Lorat
- Department of Radiotherapy and Radiation Oncology, Medical Center, Saarland University, Homburg/Saar, Germany.
| | - Jochen Fleckenstein
- Department of Radiotherapy and Radiation Oncology, Medical Center, Saarland University, Homburg/Saar, Germany
| | - Patric Görlinger
- Department of Radiotherapy and Radiation Oncology, Medical Center, Saarland University, Homburg/Saar, Germany.,Department of Anesthesiology, DRK Hospitals Berlin Westend, Berlin, Germany
| | - Christian Rübe
- Department of Radiotherapy and Radiation Oncology, Medical Center, Saarland University, Homburg/Saar, Germany
| | - Claudia E Rübe
- Department of Radiotherapy and Radiation Oncology, Medical Center, Saarland University, Homburg/Saar, Germany
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2
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Abstract
Type I collagen is a fibrillar protein, a member of a large family of collagen proteins. It is present in most body tissues, usually in combination with other collagens and other components of extracellular matrix. Its synthesis is increased in various pathological situations, in healing wounds, in fibrotic tissues and in many tumors. After extraction from collagen-rich tissues it is widely used in studies of cell behavior, especially those of fibroblasts and myofibroblasts. Cells cultured in a classical way, on planar plastic dishes, lack the third dimension that is characteristic of body tissues. Collagen I forms gel at neutral pH and may become a basis of a 3D matrix that better mimics conditions in tissue than plastic dishes.
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Affiliation(s)
- Jiří Kanta
- a Department of Medical Biochemistry; Medical Faculty in Hradec Králové; Charles University ; Prague , Czech Republic
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3
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da Rocha-Azevedo B, Ho CH, Grinnell F. PDGF‑stimulated dispersal of cell clusters and disruption of fibronectin matrix on three-dimensional collagen matrices requires matrix metalloproteinase-2. Mol Biol Cell 2015; 26:1098-105. [PMID: 25589674 PMCID: PMC4357509 DOI: 10.1091/mbc.e14-09-1396] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Previous studies showed that morphogenic cell clustering depends on fibronectin fibrillar matrix assembly under procontractile conditions. The present study shows that disruption of fibronectin matrix necessary for dispersal of cell clusters under promigratory conditions requires matrix metalloproteinases, especially MMP-2. Formation of cell clusters is a common morphogenic cell behavior observed during tissue and organ development and homeostasis, as well as during pathological disorders. Dynamic regulation of cell clustering depends on the balance between contraction of cells into clusters and migration of cells as dispersed individuals. Previously we reported that under procontractile culture conditions, fibronectin fibrillar matrix assembly by human fibroblasts functioned as a nucleation center for cell clustering on three-dimensional collagen matrices. Here we report that switching preformed cell clusters from procontractile to promigratory culture conditions results in cell dispersal out of clusters and disruption of FN matrix. Experiments using small interfering RNA silencing and pharmacological inhibition demonstrated that matrix metalloproteinase activity involving MMP-2 was necessary for fibronectin matrix disruption and dispersal of cell clusters.
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Affiliation(s)
| | - Chin-Han Ho
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390-9039
| | - Frederick Grinnell
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, TX 75390-9039
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4
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Attachment-regulated signaling networks in the fibroblast-populated 3D collagen matrix. Sci Rep 2014; 3:1880. [PMID: 23697962 PMCID: PMC6504840 DOI: 10.1038/srep01880] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 05/02/2013] [Indexed: 01/03/2023] Open
Abstract
Fibroblasts in the attached collagen matrix are in a pro-survival, pro-proliferative state relative to fibroblasts in the released collagen matrix, such that matrix cell number increases in the former over time. Gene array data from attached vs. released matrices were analyzed for putative networks that regulated matrix cell number. Select networks then underwent augmentation and/or inhibition in order to determine their biologic relevance. Matrix stress-release was associated with modulation of signaling networks that involved IL6, IL8, NF-κB, TGF-β1, p53, interferon-γ, and other entities as central participants. Perturbation of select networks in multiple fibroblast strains suggested that IL6 and IL8 secretion may have been involved in preservation of matrix cell population in the released matrix, though there was variability in testing results among the strains. NF-κB activation may have contributed to the induction of population regression after matrix release.
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5
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Smithmyer ME, Sawicki LA, Kloxin AM. Hydrogel scaffolds as in vitro models to study fibroblast activation in wound healing and disease. Biomater Sci 2014; 2:634-650. [PMID: 25379176 PMCID: PMC4217222 DOI: 10.1039/c3bm60319a] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 02/19/2014] [Indexed: 12/16/2022]
Abstract
Wound healing results from complex signaling between cells and their environment in response to injury. Fibroblasts residing within the extracellular matrix (ECM) of various connective tissues are critical for matrix synthesis and repair. Upon injury or chronic insult, these cells activate into wound-healing cells, called myofibroblasts, and repair the damaged tissue through enzyme and protein secretion. However, misregulation and persistence of myofibroblasts can lead to uncontrolled accumulation of matrix proteins, tissue stiffening, and ultimately disease. Extracellular cues are important regulators of fibroblast activation and have been implicated in their persistence. Hydrogel-based culture models have emerged as useful tools to examine fibroblast response to ECM cues presented during these complex processes. In this Mini-Review, we will provide an overview of these model systems, which are built upon naturally-derived or synthetic materials, and mimic relevant biophysical and biochemical properties of the native ECM with different levels of control. Additionally, we will discuss the application of these hydrogel-based systems for the examination of fibroblast function and fate, including adhesion, migration, and activation, as well as approaches for mimicking both static and temporal aspects of extracellular environments. Specifically, we will highlight hydrogels that have been used to investigate the effects of matrix rigidity, protein binding, and cytokine signaling on fibroblast activation. Last, we will describe future directions for the design of hydrogels to develop improved synthetic models that mimic the complex extracellular environment.
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Affiliation(s)
- Megan E. Smithmyer
- Chemical & Biomolecular Engineering , University of Delaware , Newark , DE 19716 , USA
| | - Lisa A. Sawicki
- Chemical & Biomolecular Engineering , University of Delaware , Newark , DE 19716 , USA
| | - April M. Kloxin
- Chemical & Biomolecular Engineering , University of Delaware , Newark , DE 19716 , USA
- Materials Science & Engineering , University of Delaware , Newark , DE 19716 , USA .
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6
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Abstract
Fibroblast migration is essential to normal wound healing and pathological matrix deposition in fibrosis. This review summarizes our understanding of how fibroblasts navigate 2D and 3D extracellular matrices, how this behavior is influenced by the architecture and mechanical properties of the matrix, and how migration is integrated with the other principle functions of fibroblasts, including matrix deposition, contraction, and degradation.
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Affiliation(s)
- Daniel J Tschumperlin
- Department of Environmental Health, Molecular and Integrative Physiological Sciences, Harvard School of Public Health, Boston, Massachusetts
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7
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Chao J, Peña T, Heimann DG, Hansen C, Doyle DA, Yanala UR, Guenther TM, Carlson MA. Expression of green fluorescent protein in human foreskin fibroblasts for use in 2D and 3D culture models. Wound Repair Regen 2014; 22:134-40. [DOI: 10.1111/wrr.12121] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Accepted: 09/04/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Jie Chao
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - Tiffany Peña
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - Dean G. Heimann
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - Chris Hansen
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - David A. Doyle
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - Ujwal R. Yanala
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - Timothy M. Guenther
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
| | - Mark A. Carlson
- Departments of Surgery; University of Nebraska Medical Center; Omaha Nebraska USA
- VA Nebraska-Western Iowa Health Care System; Omaha Nebraska USA
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8
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Provenzano PP, Keely PJ. Mechanical signaling through the cytoskeleton regulates cell proliferation by coordinated focal adhesion and Rho GTPase signaling. J Cell Sci 2011; 124:1195-205. [PMID: 21444750 DOI: 10.1242/jcs.067009] [Citation(s) in RCA: 366] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The notion that cell shape and spreading can regulate cell proliferation has evolved over several years, but only recently has this been linked to forces from within and upon the cell. This emerging area of mechanical signaling is proving to be wide-spread and important for all cell types. The microenvironment that surrounds cells provides a complex spectrum of different, simultaneously active, biochemical, structural and mechanical stimuli. In this milieu, cells probe the stiffness of their microenvironment by pulling on the extracellular matrix (ECM) and/or adjacent cells. This process is dependent on transcellular cell-ECM or cell-cell adhesions, as well as cell contractility mediated by Rho GTPases, to provide a functional linkage through which forces are transmitted through the cytoskeleton by intracellular force-generating proteins. This Commentary covers recent advances in the underlying mechanisms that control cell proliferation by mechanical signaling, with an emphasis on the role of 3D microenvironments and in vivo extracellular matrices. Moreover, as there is much recent interest in the tumor-stromal interaction, we will pay particular attention to exciting new data describing the role of mechanical signaling in the progression of breast cancer.
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Affiliation(s)
- Paolo P Provenzano
- Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
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9
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Helary C, Zarka M, Giraud-Guille MM. Fibroblasts within concentrated collagen hydrogels favour chronic skin wound healing. J Tissue Eng Regen Med 2011; 6:225-37. [DOI: 10.1002/term.420] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 02/17/2011] [Indexed: 01/07/2023]
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10
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Kossodo S, Wong WR, Simon G, Kochevar IE. Effects of UVR and UVR-induced Cytokines on Production of Extracellular Matrix Proteins and Proteases by Dermal Fibroblasts Cultured in Collagen Gels¶. Photochem Photobiol 2011. [DOI: 10.1111/j.1751-1097.2004.tb09861.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Schedin P, Keely PJ. Mammary gland ECM remodeling, stiffness, and mechanosignaling in normal development and tumor progression. Cold Spring Harb Perspect Biol 2011; 3:a003228. [PMID: 20980442 DOI: 10.1101/cshperspect.a003228] [Citation(s) in RCA: 324] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Cells of the mammary gland are in intimate contact with other cells and with the extracellular matrix (ECM), both of which provide not only a biochemical context, but a mechanical context as well. Cell-mediated contraction allows cells to sense the stiffness of their microenvironment, and respond with appropriate mechanosignaling events that regulate gene expression and differentiation. ECM composition and organization are tightly regulated throughout development of the mammary gland, resulting in corresponding regulation of the mechanical environment and proper tissue architecture. Mechanical regulation is also at play during breast carcinoma progression, as changes in ECM deposition, composition, and organization accompany breast carcinoma. These changes result in stiffer matrices that activate mechanosignaling pathways and thereby induce cell proliferation, facilitate local tumor cell invasion, and promote progression. Thus, understanding the role of forces in the mammary gland is crucial to understanding both normal developmental and pathological processes.
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Affiliation(s)
- Pepper Schedin
- Department of Medicine, Division of Medical Oncology, University of Colorado, Denver, Colorado 80045, USA
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12
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Pinto MMPDL, Santos NFG, Amaral A. Current status of biodosimetry based on standard cytogenetic methods. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2010; 49:567-81. [PMID: 20617329 DOI: 10.1007/s00411-010-0311-3] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Accepted: 06/19/2010] [Indexed: 05/19/2023]
Abstract
Knowledge about dose levels in radiation protection is an important step for risk assessment. However, in most cases of real or suspected accidental exposures to ionizing radiation (IR), physical dosimetry cannot be performed for retrospective estimates. In such situations, biological dosimetry has been proposed as an alternative for investigation. Briefly, biodosimetry can be defined as individual dose evaluation based on biological endpoints induced by IR (so-called biomarkers). The relationship between biological endpoints and absorbed dose is not always straightforward: nausea, vomiting and diarrhoea, for example, are the most well-known biological effects of individual irradiation, but a precise correlation between those symptoms and absorbed dose is hardly achieved. The scoring of unstable chromosomal-type aberrations (such as dicentrics and rings) and micronuclei in mitogen-stimulated peripheral blood, up till today, has been the most extensively biodosimetry assay employed for such purposes. Dicentric assay is the gold standard in biodosimetry, since its presence is generally considered to be specific to radiation exposure; scoring of micronuclei (a kind of by-product of chromosomal damages) is easier and faster than that of dicentrics for dose assessment. In this context, the aim of this work is to present an overview on biodosimetry based on standard cytogenetic methods, highlighting its advantages and limitations as tool in monitoring of radiation workers' doses or investigation into accidental exposures. Recent advances and perspectives are also briefly presented.
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13
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Giraud Guille MM, Helary C, Vigier S, Nassif N. Dense fibrillar collagen matrices for tissue repair. SOFT MATTER 2010; 6:4963-4967. [PMID: 34154305 DOI: 10.1039/c0sm00260g] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The preparation of dense fibrillar collagen matrices, through a sol/gel transition at variable concentrations, offers routes to produce a range of simple, non toxic materials. Concentrated hydrogels entrapping cells show enhanced properties in terms of reduced contraction and enhanced cell proliferation . Dense fibrillar matrices attain tissue like mechanical properties and show ultrastructures described in connective tissues, namely liquid crystalline cholesteric geometries. Their colonization by cells and possible association with a mineral phase in a tissue like manner validate their use as biomimetic materials for regenerative medicine.
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Affiliation(s)
- Marie Madeleine Giraud Guille
- University Pierre and Marie Curie-Paris 6, Ecole Pratique des Hautes Etudes, CNRS-UMR 7574, Laboratoire Chimie de la Matière Condensée de Paris, 4 place Jussieu, 75005, Paris, France.
| | - Christophe Helary
- University Pierre and Marie Curie-Paris 6, Ecole Pratique des Hautes Etudes, CNRS-UMR 7574, Laboratoire Chimie de la Matière Condensée de Paris, 4 place Jussieu, 75005, Paris, France.
| | - Sylvain Vigier
- University Pierre and Marie Curie-Paris 6, Ecole Pratique des Hautes Etudes, CNRS-UMR 7574, Laboratoire Chimie de la Matière Condensée de Paris, 4 place Jussieu, 75005, Paris, France.
| | - Nadine Nassif
- University Pierre and Marie Curie-Paris 6, Ecole Pratique des Hautes Etudes, CNRS-UMR 7574, Laboratoire Chimie de la Matière Condensée de Paris, 4 place Jussieu, 75005, Paris, France.
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14
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Wang C, Varshney RR, Wang DA. Therapeutic cell delivery and fate control in hydrogels and hydrogel hybrids. Adv Drug Deliv Rev 2010; 62:699-710. [PMID: 20138940 DOI: 10.1016/j.addr.2010.02.001] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Revised: 01/29/2010] [Accepted: 02/01/2010] [Indexed: 11/18/2022]
Abstract
Hydrogels are synthetic or natural polymer networks that closely mimic native extracellular matrices. As hydrogel-based vehicles are being increasingly employed in therapeutic cell delivery, two inherent traits of most common hydrogels, namely low cell affinity and high cell constraint, have significantly drawn the attention of biomedical community. These two properties lead to the unfavourable settlement of anchorage-dependent cells (ADCs) and unsatisfactory cell delivery or tissue formation in hydrogel matrices. Tissue engineers have correspondingly made many efforts involving chemical modification or physical hybridisation to facilitate ADC settlement and promote tissue formation. On the other hand, these two 'bio-inert' characteristics have particularly favoured oncological cell therapists, who expect to utilize hydrogels to provide sufficiently high confinement of the delivered cells for anti-cancer purposes. In general, control of cell fate and behaviours in these three-dimensional (3D) microenvironments has become the central aim for hydrogel-mediated cell delivery, towards which various models based on hydrogels and their hybrids have emerged. In this paper, we will first review the development of strategies aiming to overcome the aforementioned two 'shortcomings' by (i) establishing ADC survival and (ii) creating space for tissue formation respectively, and then introduce how people take advantage of these 'disadvantages' of hydrogel encapsulation for (iii) an enhanced confinement of cell motion.
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Affiliation(s)
- Chunming Wang
- Nanyang Technological University, Singapore, Republic of Singapore
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15
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Mao Y, Schwarzbauer JE. Accessibility to the Fibronectin Synergy Site in a 3D Matrix Regulates Engagement of α 5β 1 versus α vβ 3 Integrin Receptors. ACTA ACUST UNITED AC 2009; 13:267-77. [PMID: 17162669 DOI: 10.1080/15419060601072215] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cell adhesion and migration on fibronectin (FN) extracellular matrix are mediated by integrin receptors. Integrins alpha5beta1 and alphavbeta3 require the RGD cell-binding sequence in FN, but alpha5beta1 also requires the nearby synergy site for maximal binding. In this study, we investigated how differences in the numbers of RGD or synergy sites within a three-dimensional (3D) FN-rich matrix influence cell adhesion and migration. CHO cell adhesion, spreading, and migration were reduced on 3D chimeric matrix containing FN lacking RGD (FN(RGD-)). Incorporation of FN with mutation of the synergy site (FN(syn-)), however, resulted in selective usage of integrins. CHO cells expressing alpha5beta1 showed decreased interactions with FN(syn-) chimeric matrix. In contrast, the presence of FN(syn-) had no effect on CHOalphavbeta3 cell migration. Interestingly, CHOalpha5/alphavbeta3 cells expressing both integrins selectively used alpha5beta1 for migration on wild type FN matrix but preferred alphavbeta3 for migration on FN(syn-) chimeric matrix. Thus sequestration or exposure of the FN synergy site within a 3D matrix may represent a novel mechanism for regulating cell functions through differential usage of integrin receptors. [Supplementary materials are available for this article. Go to the publisher's online edition of Cell Communication and Adhesion for the following free supplemental resource: a video recording shows migration of HT1080 cells on 3D matrix. HT1080 cells were allowed to attach to the matrix in serum-free DMEM for 2 h. FBS was then added to the medium to a final concentration of 10% and video recording was started. Images were taken every 5 min for 2 h. The video plays at 6 frames/s.].
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Affiliation(s)
- Yong Mao
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544-1014, USA
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16
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Hadjipanayi E, Mudera V, Brown RA. Close dependence of fibroblast proliferation on collagen scaffold matrix stiffness. J Tissue Eng Regen Med 2009; 3:77-84. [PMID: 19051218 DOI: 10.1002/term.136] [Citation(s) in RCA: 207] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Human dermal fibroblasts (HDFs) in free-floating collagen matrices show minimal proliferation, although this may increase when the matrix is 'under tension'. We have investigated the detailed mechanics underlying one of the possible controls of this important cell behaviour, in particular the hypothesis that this is a response to substrate stiffness. Hyperhydrated collagen gels were plastic-compressed (PC) to give a predetermined collagen density and stiffness. Mechanical properties were tested using a dynamic mechanical analyser; cell number by Alamar blue assay. In the stiffest PC matrices, cell proliferation was rapid and seeding density-dependent, with a population doubling time of 2 days. In contrast, compliant attached matrices showed a 4 day lag period and a doubling time of 6 days. HDF growth was directly related to matrix stiffness, such that increasing stiffness using a range of compression levels (0-75% fluid removal) supported increasing proliferation rate, doubling times and matrix elastic modulus. HDF quiescence in compliant matrices was reversible, such that increasing stiffness in situ by compression at 1 and 5 days initiated proliferation. We conclude that collagen matrix stiffness regulates proliferation of fibroblasts (a duro-response), with important implications for understanding fibroblast-matrix feedback controls during wound healing and the design and regulation of engineered connective tissues based on collagen and other hydrogel-based scaffolds.
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Affiliation(s)
- E Hadjipanayi
- University College London (UCL), Tissue Repair and Engineering Centre, Institute of Orthopaedics, Stanmore Campus, London, UK
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17
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Chiquet M, Gelman L, Lutz R, Maier S. From mechanotransduction to extracellular matrix gene expression in fibroblasts. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:911-20. [PMID: 19339214 DOI: 10.1016/j.bbamcr.2009.01.012] [Citation(s) in RCA: 257] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 01/12/2009] [Accepted: 01/22/2009] [Indexed: 12/22/2022]
Abstract
Tissue mechanics provide an important context for tissue growth, maintenance and function. On the level of organs, external mechanical forces largely influence the control of tissue homeostasis by endo- and paracrine factors. On the cellular level, it is well known that most normal cell types depend on physical interactions with their extracellular matrix in order to respond efficiently to growth factors. Fibroblasts and other adherent cells sense changes in physical parameters in their extracellular matrix environment, transduce mechanical into chemical information, and integrate these signals with growth factor derived stimuli to achieve specific changes in gene expression. For connective tissue cells, production of the extracellular matrix is a prominent response to changes in mechanical load. We will review the evidence that integrin-containing cell-matrix adhesion contacts are essential for force transmission from the extracellular matrix to the cytoskeleton, and describe novel experiments indicating that mechanotransduction in fibroblasts depends on focal adhesion adaptor proteins that might function as molecular springs. We will stress the importance of the contractile actin cytoskeleton in balancing external with internal forces, and describe new results linking force-controlled actin dynamics directly to the expression of specific genes, among them the extracellular matrix protein tenascin-C. As assembly lines for diverse signaling pathways, matrix adhesion contacts are now recognized as the major sites of crosstalk between mechanical and chemical stimuli, with important consequences for cell growth and differentiation.
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Affiliation(s)
- Matthias Chiquet
- Friedrich Miescher Institute for Biomedical Research, Novartis Research Foundation, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.
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18
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Erler JT, Weaver VM. Three-dimensional context regulation of metastasis. Clin Exp Metastasis 2008; 26:35-49. [PMID: 18814043 DOI: 10.1007/s10585-008-9209-8] [Citation(s) in RCA: 261] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2008] [Accepted: 09/01/2008] [Indexed: 02/04/2023]
Abstract
Tumor progression ensues within a three-dimensional microenvironment that consists of cellular and non-cellular components. The extracellular matrix (ECM) and hypoxia are two non-cellular components that potently influence metastasis. ECM remodeling and collagen cross-linking stiffen the tissue stroma to promote transformation, tumor growth, motility and invasion, enhance cancer cell survival, enable metastatic dissemination, and facilitate the establishment of tumor cells at distant sites. Matrix degradation can additionally promote malignant progression and metastasis. Tumor hypoxia is functionally linked to altered stromal-epithelial interactions. Hypoxia additionally induces the expression of pro-migratory, survival and invasion genes, and up-regulates expression of ECM components and modifying enzymes, to enhance tumor progression and metastasis. Synergistic interactions between matrix remodeling and tumor hypoxia influence common mechanisms that maximize tumor progression and cooperate to drive metastasis. Thus, clarifying the molecular pathways by which ECM remodeling and tumor hypoxia intersect to promote tumor progression should identify novel therapeutic targets.
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Affiliation(s)
- Janine T Erler
- Hypoxia and Metastasis Team, Section of Cell and Molecular Biology, The Institute of Cancer Research, London, UK.
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19
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Gupta V, Werdenberg JA, Mendez JS, Jane Grande-Allen K. Influence of strain on proteoglycan synthesis by valvular interstitial cells in three-dimensional culture. Acta Biomater 2008; 4:88-96. [PMID: 17928282 DOI: 10.1016/j.actbio.2007.08.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 08/14/2007] [Accepted: 08/20/2007] [Indexed: 11/29/2022]
Abstract
Differently loaded regions of the mitral valve contain distinct amounts and types of proteoglycans (PGs); these PG profiles are altered in abnormal loading and disease conditions. We developed an in vitro three-dimensional model to analyze PGs secreted by valvular interstitial cells (VICs) isolated from distinct regions of porcine mitral valves (leaflet or chordae) and subjected to either biaxial or uniaxial mechanical constraints. In addition, the PGs, DNA and collagen content of the collagen gels was monitored over time. All three PGs previously found in heart valves (decorin, biglycan and versican) were present in the collagen gels and the conditioned medium. Compared to unconstrained gels, the constrained collagen gels (whether biaxially or uniaxially loaded) retained more decorin and biglycan but less versican. However, the conditioned medium from constrained collagen gels contained higher amounts of all three PGs than did medium from unconstrained gels. Constrained collagen gels containing leaflet cells retained more decorin and biglycan than did those containing chordal cells. DNA content was maintained early in the culture period but was reduced by 55-80% after 7 days, whereas PG synthesis increased over time. At the end of the culture period, the cell density was highest in the biaxial region of gels seeded with leaflet cells. In contrast, collagen content in both constrained and unconstrained gels remained consistent over culture duration. This study provides valuable information about the role of applied loading on proteoglycan segregation, which should aid in tissue engineering applications and for understanding valve biology and pathology.
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Affiliation(s)
- Vishal Gupta
- Department of Bioengineering, Rice University, Houston, TX 77251-1892, USA
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20
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Watterson KR, Lanning DA, Diegelmann RF, Spiegel S. Regulation of fibroblast functions by lysophospholipid mediators: Potential roles in wound healing. Wound Repair Regen 2007; 15:607-16. [DOI: 10.1111/j.1524-475x.2007.00292.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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21
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Fuseler JW, Millette CF, Davis JM, Carver W. Fractal and image analysis of morphological changes in the actin cytoskeleton of neonatal cardiac fibroblasts in response to mechanical stretch. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2007; 13:133-43. [PMID: 17367553 DOI: 10.1017/s1431927607070225] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 01/11/2007] [Indexed: 05/10/2023]
Abstract
Cardiac fibroblasts are the most numerous cells in the heart and are critical in the formation and normal functioning of the organ. Cardiac fibroblasts are firmly attached to and surrounded by extracellular matrix (ECM). Mechanical forces transmitted through interaction with the ECM can result in changes of overall cellular shape, cytoskeletal organization, proliferation, and gene expression of cardiac fibroblasts. These responses may be different in the normally functioning heart, when compared with various pathological conditions, including inflammation or hypertrophy. It is apparent that cellular phenotype and physiology, in turn, are affected by multiple signal transduction pathways modulated directly by the state of polymerization of the actin cytoskeleton. Morphological changes in actin organization resulting from response to adverse conditions in fibroblasts and other cell types are basically descriptive. Some studies have approached quantifying changes in actin cytoskeletal morphology, but these have involved complex and difficult procedures. In this study, we apply image analysis and non-Euclidian geometrical fractal analysis to quantify and describe changes induced in the actin cytoskeleton of cardiac fibroblasts responding to mechanical stress. Characterization of these rapid responses of fibroblasts to mechanical stress may provide insight into the regulation of fibroblasts behavior and gene expression during heart development and disease.
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Affiliation(s)
- John W Fuseler
- Department of Cell and Developmental Biology and Anatomy, University of South Carolina, School of Medicine, Columbia, South Carolina 29209, USA.
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22
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Toriseva MJ, Ala-aho R, Karvinen J, Baker AH, Marjomäki VS, Heino J, Kähäri VM. Collagenase-3 (MMP-13) Enhances Remodeling of Three-Dimensional Collagen and Promotes Survival of Human Skin Fibroblasts. J Invest Dermatol 2007; 127:49-59. [PMID: 16917496 DOI: 10.1038/sj.jid.5700500] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Collagenase-3 (MMP-13) is a matrix metalloproteinase capable of cleaving a multitude of extracellular matrix proteins in addition to fibrillar collagens. Human MMP-13 is expressed by fibroblasts in chronic cutaneous ulcers, but not in normally healing adult skin wounds. However, MMP-13 is produced by fibroblasts in adult gingival and in fetal skin wounds characterized by rapid collagen remodeling and scarless healing. Here, we have examined the role of human MMP-13 in remodeling of three-dimensional (3D) collagenous matrix by primary adult human skin fibroblasts. The high level of human MMP-13 expression by fibroblasts achieved by adenoviral gene delivery resulted in potent enhancement of remodeling and contraction of 3D collagen. Fibroblasts expressing MMP-13 in 3D collagen possessed altered filamentous actin morphology with patch-like actin distribution in cell extensions. The expression of MMP-13 promotes survival and proliferation of fibroblasts in floating collagen gel, and results in activation of Akt and extracellular signal-regulated kinase-1/2 by these cells. The results provide evidence for a novel role for human MMP-13 in regulating dermal fibroblast survival, proliferation, and interaction in 3D collagen, which may be an important survival mechanism for fibroblasts in chronic skin ulcers and contribute to scarless healing of adult gingival and fetal skin wounds.
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23
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Abstract
Cardiac function is determined by the dynamic interaction of various cell types and the extracellular matrix that composes the heart. This interaction varies with the stage of development and the degree and duration of mechanical, chemical, and electrical signals between the various cell types and the ECM. Understanding how these complex signals interact at the molecular, cellular, and organ levels is critical to understanding the function of the heart under a variety of physiological and pathophysiological conditions. Quantitative approaches, both in vivo and in vitro, are essential to understand the dynamic interaction of mechanical, chemical, and electrical stimuli that govern cardiac function. The fibroblast can thus be a friend in normal function or a foe in pathophysiological conditions.
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Affiliation(s)
- Troy A Baudino
- Department of Cell and Developmental Biology and Anatomy, School of Medicine, University of South Carolina, Columbia, SC 29208, USA
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24
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Beacham DA, Cukierman E. Stromagenesis: the changing face of fibroblastic microenvironments during tumor progression. Semin Cancer Biol 2005; 15:329-41. [PMID: 15970443 DOI: 10.1016/j.semcancer.2005.05.003] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
During tumorigenesis, reciprocal changes in stromal fibroblasts and tumor cells induce changes to the neoplastic microenvironmental landscape. In stromagenesis, both the complex network of bi-directional stromal fibroblastic signaling pathways and the stromal extracellular matrix are modified. The presence of a 'primed' stroma during the early, reversible stage of tumorigenesis is optimal for stromal-directed therapeutic intervention. Three-dimensional (3D) cell culture systems have been developed that mimic the in vivo microenvironment. These systems provide unique experimental tools to identify early alterations in stromagenesis that are supportive of tumor progression with the ultimate goal of blocking neoplastic permissiveness and restoring normal phenotypes.
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Affiliation(s)
- Dorothy A Beacham
- Fox Chase Cancer Center, Basic Science/Tumor Cell Biology, 333 Cottman Avenue, Philadelphia, PA 19111-2497, USA
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25
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Walker JL, Fournier AK, Assoian RK. Regulation of growth factor signaling and cell cycle progression by cell adhesion and adhesion-dependent changes in cellular tension. Cytokine Growth Factor Rev 2005; 16:395-405. [PMID: 15886049 DOI: 10.1016/j.cytogfr.2005.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Accepted: 03/07/2005] [Indexed: 12/20/2022]
Abstract
The proliferation of most non-transformed cell types requires cell adhesion and cellular tension as well as exposure to mitogenic growth factors. Integrins and cadherins provide the adhesion signals, which ultimately allow for the cytoskeletal changes that control cellular tension. This review discusses the roles of integrins, cadherins, and the actin cytoskeleton as mediators of the mechanical tension critical for growth factor-dependent signaling and cell cycle progression.
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Affiliation(s)
- Janice L Walker
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, 19104-6084, USA
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26
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Edin ML, Juliano RL. Raf-1 serine 338 phosphorylation plays a key role in adhesion-dependent activation of extracellular signal-regulated kinase by epidermal growth factor. Mol Cell Biol 2005; 25:4466-75. [PMID: 15899852 PMCID: PMC1140616 DOI: 10.1128/mcb.25.11.4466-4475.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Activation of the extracellular signal-regulated kinase (ERK) 1/2 cascade by polypeptide growth factors is tightly coupled to adhesion to extracellular matrix in nontransformed cells. Raf-1, the initial kinase in this cascade, is intricately regulated by phosphorylation, localization, and molecular interactions. We investigated the complex interactions between Raf-1, protein kinase A (PKA), and p21-activated kinase (PAK) to determine their roles in the adhesion dependence of signaling from epidermal growth factor (EGF) to ERK. We conclude that Raf-1 phosphorylation on serine 338 (S338) is a critical step that is inhibited in suspended cells. Restoration of phosphorylation at S338, either by expression of highly active PAK or by expression of an S338 phospho-mimetic Raf-1 mutation, led to a partial rescue of ERK activation in suspended cells. Raf-1 inhibition in suspension was not due to excessive negative regulation on inhibitory sites S43 and S259, as these serines were largely dephosphorylated in suspended cells. Finally, strong phosphorylation of Raf-1 S338 provided resistance to PKA-mediated inhibition of ERK activation. Phosphorylation at Raf-1 S43 and S259 by PKA only weakly inhibited EGF activation of Raf-1 and ERK when cells maintained high Raf-1 S338 phosphorylation.
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Affiliation(s)
- Matthew L Edin
- Department of Pharmacology, University of North Carolina, Chapel Hill, 1017 Mary Ellen Jones Building, CB 7365, Chapel Hill, NC 27599-7365, USA
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27
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Roth JM, Akalu A, Zelmanovich A, Policarpio D, Ng B, MacDonald S, Formenti S, Liebes L, Brooks PC. Recombinant alpha2(IV)NC1 domain inhibits tumor cell-extracellular matrix interactions, induces cellular senescence, and inhibits tumor growth in vivo. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:901-11. [PMID: 15743801 PMCID: PMC1602358 DOI: 10.1016/s0002-9440(10)62310-3] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cellular interaction with the extracellular matrix is thought to be a critical event in controlling angiogenesis and tumor growth. In our previous studies, genetically distinct noncollagenous (NC) domains of type-IV collagen were shown to interact with integrin receptors expressed on the surface of endothelial cells. Moreover, these NC1 domains were shown to inhibit angiogenesis in vivo. Here, we provide evidence that a recombinant form of the alpha2(IV)NC1 domain of type-IV collagen could bind integrins alpha1beta1 and alphavbeta3 expressed on melanoma cells and inhibit tumor cell adhesion in a ligand-specific manner. Systemic administration of recombinant alpha2(IV)NC1 domain potently inhibited M21 melanoma tumor growth within full thickness human skin and exhibited a dose-dependent inhibition of tumor growth in nude mice. Interestingly, alpha2(IV)NC1 domain enhanced cellular senescence in tumor cells in vitro and in vivo. Taken together, these results suggest that recombinant alpha2(IV)NC1 domain is not only a potent anti-angiogenic reagent, but it also directly impacts tumor cell behavior. Thus, alpha2(IV)NC1 domain represents a potent inhibitor of tumor growth by impacting both endothelial and tumor cell compartments.
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Affiliation(s)
- Jennifer M Roth
- Department of Radiation Oncology, New York University School of Medicine, 400 East 34th St., New York, NY 10016, USA
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Wozniak MA, Modzelewska K, Kwong L, Keely PJ. Focal adhesion regulation of cell behavior. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1692:103-19. [PMID: 15246682 DOI: 10.1016/j.bbamcr.2004.04.007] [Citation(s) in RCA: 695] [Impact Index Per Article: 34.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 01/23/2004] [Accepted: 04/22/2004] [Indexed: 12/18/2022]
Abstract
Focal adhesions lie at the convergence of integrin adhesion, signaling and the actin cytoskeleton. Cells modify focal adhesions in response to changes in the molecular composition, two-dimensional (2D) vs. three-dimensional (3D) structure, and physical forces present in their extracellular matrix environment. We consider here how cells use focal adhesions to regulate signaling complexes and integrin function. Furthermore, we examine how this regulation controls complex cellular behaviors in response to matrices of diverse physical and biochemical properties. One event regulated by the physical structure of the ECM is phosphorylation of focal adhesion kinase (FAK) at Y397, which couples FAK to several signaling pathways that regulate cell proliferation, survival, migration, and invasion.
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Affiliation(s)
- Michele A Wozniak
- Department of Pharmacology, University of Wisconsin, 3630 MSC, 1300 University Ave, Madison 53706, USA
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29
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Abstract
The tissue microenvironment regulates mammary gland development and tissue homeostasis through soluble, insoluble and cellular cues that operate within the three dimensional architecture of the gland. Disruption of these critical cues and loss of tissue architecture characterize breast tumors. The developing and lactating mammary gland are also subject to a plethora of tensional forces that shape the morphology of the gland and orchestrate its functionally differentiated state. Moreover, malignant transformation of the breast is associated with dramatic changes in gland tension that include elevated compression forces, high tensional resistance stresses and increased extracellular matrix stiffness. Chronically increased mammary gland tension may influence tumor growth, perturb tissue morphogenesis, facilitate tumor invasion, and alter tumor survival and treatment responsiveness. Because mammary tissue differentiation is compromised by high mechanical force and transformed cells exhibit altered mechanoresponsiveness, malignant transformation of the breast may be functionally linked to perturbed tensional-homeostasis. Accordingly, it will be important to define the role of tensional force in mammary gland development and tumorigenesis. Additionally, it will be critical to identify the key molecular elements regulating tensional-homeostasis of the mammary gland and thereafter to characterize their associated mechanotransduction pathways.
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Affiliation(s)
- Matthew J Paszek
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6383, USA
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Carlson MA, Longaker MT, Thompson JS. Modulation of FAK, Akt, and p53 by stress release of the Fibroblast-Populated collagen matrix1,2. J Surg Res 2004; 120:171-7. [PMID: 15234210 DOI: 10.1016/j.jss.2003.12.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2003] [Indexed: 12/11/2022]
Abstract
BACKGROUND Fibroblast survival in a three-dimensional collagen matrix is dependent in part upon the rigid anchorage of the matrix to tissue culture plastic. We hypothesized that focal adhesion kinase (FAK) and protein kinase B (Akt) would be activated and that the p53 level would be low in the rigidly anchored (attached) collagen matrix; loss of anchorage (detachment) was hypothesized to have the opposite effects. MATERIALS AND METHODS Human foreskin fibroblasts were cultured in attached bovine collagen matrices for 48 h before detachment as free-floating matrices. At various time points postrelease, matrix lysates were blotted for the proteins of interest, and the terminal deoxynucleotidyltransferase-mediated dUTP nick-end label assay was performed on both whole matrices and cytospin preparations. Irradiated monolayer fibroblasts were used as positive controls for the amount of p53 protein. RESULTS Terminal deoxynucleotidyltransferase-mediated dUTP nick-end label positivity in attached versus detached matrices (at 24 h post detachment) was 0.7 +/- 03 versus 5.3 +/- 1.7% (P < 0.05, unpaired t test). FAK and Akt were phosphorylated (activated) in the attached matrix; there was a near complete of loss of both activated forms within 4 h of matrix detachment. Irradiated monolayer fibroblasts had increased levels of p53, mdm2, and p21. In contrast, the p53, mdm2, and p21 levels were just at the level of detection in the attached matrix, but were induced 5- to 10-fold within 2-4 h after matrix detachment. CONCLUSIONS FAK and Akt are activated in the attached fibroblast-populated collagen matrix whereas the p53 level is relatively low; matrix detachment downregulates FAK and Akt activity and induces p53. The state of mechanical anchorage of the collagen matrix regulates the survival of embedded fibroblasts through a mechanism which may involve FAK.
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Affiliation(s)
- Mark A Carlson
- Department of Surgery, University of Nebraska Medical Center and the Omaha VA Medical Center, 4101 Woolworth Avenue, Omaha, NE 68105, USA.
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31
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Kessler-Becker D, Krieg T, Eckes B. Expression of pro-inflammatory markers by human dermal fibroblasts in a three-dimensional culture model is mediated by an autocrine interleukin-1 loop. Biochem J 2004; 379:351-8. [PMID: 14686880 PMCID: PMC1224070 DOI: 10.1042/bj20031371] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Revised: 12/17/2003] [Accepted: 12/19/2003] [Indexed: 12/23/2022]
Abstract
In vivo, fibroblasts reside in connective tissues, with which they communicate in a reciprocal way. Such cell--extracellular matrix interactions can be studied in vitro by seeding fibroblasts in collagen lattices. Depending upon the mechanical properties of the system, fibroblasts are activated to assume defined phenotypes. In the present study, we examined a transcriptional profile of primary human dermal fibroblasts cultured in a relaxed collagen environment and found relative induction (>2-fold) of 393 out of approx. 7100 transcripts when compared with the same system under mechanical tension. Despite down-regulated proliferation and matrix synthesis, cells did not become generally quiescent, since they induced transcription of numerous other genes including matrix metalloproteinases (MMPs) and growth factors/cytokines. Of particular interest was the induction of gene transcripts encoding pro-inflammatory mediators, e.g. cyclo-oxygenase-2 (COX-2), and interleukins (ILs)-1 and -6. These are apparently regulated in a hierarchical fashion, since the addition of IL-1 receptor antagonist prevented induction of COX-2, IL-1 and IL-6, but not that of MMP-1 or keratinocyte growth factor (KGF). Our results suggest strongly that skin fibroblasts are versatile cells, which adapt to their extracellular environment by displaying specific phenotypes. One such phenotype, induced by a mechanically relaxed collagen environment, is the 'pro-inflammatory' fibroblast. We propose that fibroblasts that are embedded in a matrix environment can actively participate in the regulation of inflammatory processes.
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Affiliation(s)
- Daniela Kessler-Becker
- Department of Dermatology, University of Cologne, Joseph-Stelzmann-Strasse 9, D-50931 Cologne, Germany
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Vaughan MB, Ramirez RD, Brown SA, Yang JC, Wright WE, Shay JW. A Reproducible Laser-Wounded Skin Equivalent Model to Study the Effects of AgingIn Vitro. Rejuvenation Res 2004; 7:99-110. [PMID: 15312297 DOI: 10.1089/1549168041552982] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Skin aging involves both chronological and photoaging processes. The effects of these processes are often overlapping and include changes in both the stratified epithelium and the fibroblast-rich dermis. Wound healing is frequently delayed with aging and can result in scarring. A skin equivalent model can be used to study the role of cells and the extracellular matrix in the process of wound healing. Current studies using this model employ a full-thickness wound placed atop a nonwounded dermis to mimic a partial-thickness wound. However, a true reproducible partial-thickness wound model has yet to be described. In this study, we investigated whether a laser-wounded skin equivalent would be a useful partial-thickness wound healing model. Three lasers were compared for the ability to generate a reproducible wound: an erbium-YAG, a high-powered excimer, and a low-powered excimer laser. Reepithelialization ability was tested using newborn and adult skin keratinocytes, adult esophageal keratinocytes, and cdk4-overexpressing newborn keratinocytes. Keratinocyte compartmentalization and basement membrane formation were assessed by immunofluorescence. The erbium-YAG and high-powered excimer laser cut reproducible wounds but left the remaining surface either discolored due to thermal damage and/or ragged; keratinocytes were unable to migrate into the wound area. The low-powered excimer laser cut reproducible wounds, leaving the cut surface intact and visibly unaltered; keratinocytes reepithelialized the wound in a collagenase-dependent manner within 3 days; and return of compartmentalization and basement membrane occurred within 14 days. The laser-wounded skin equivalent is an adjustable, reproducible partial-thickness wound model where keratinocyte biology akin to in vivo can be studied, and will be useful to study the effects of aging on wound healing.
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Affiliation(s)
- Melville B Vaughan
- Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
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Kossodo S, Wong WR, Simon G, Kochevar IE. Effects of UVR and UVR-induced Cytokines on Production of Extracellular Matrix Proteins and Proteases by Dermal Fibroblasts Cultured in Collagen Gels¶. Photochem Photobiol 2004. [DOI: 10.1562/0031-8655(2004)79<86:eouauc>2.0.co;2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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