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Abstract
ABSTRACT
Three-dimensional (3D) cell motility underlies essential processes, such as embryonic development, tissue repair and immune surveillance, and is involved in cancer progression. Although the cytoskeleton is a well-studied regulator of cell migration, most of what we know about its functions originates from studies conducted in two-dimensional (2D) cultures. This research established that the microtubule network mediates polarized trafficking and signaling that are crucial for cell shape and movement in 2D. In parallel, developments in light microscopy and 3D cell culture systems progressively allowed to investigate cytoskeletal functions in more physiologically relevant settings. Interestingly, several studies have demonstrated that microtubule involvement in cell morphogenesis and motility can differ in 2D and 3D environments. In this Commentary, we discuss these differences and their relevance for the understanding the role of microtubules in cell migration in vivo. We also provide an overview of microtubule functions that were shown to control cell shape and motility in 3D matrices and discuss how they can be investigated further by using physiologically relevant models.
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Affiliation(s)
- Benjamin P. Bouchet
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
| | - Anna Akhmanova
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands
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2
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Vasiliev JM, Samoylov VI. Regulatory functions of microtubules. BIOCHEMISTRY (MOSCOW) 2014; 78:37-40. [PMID: 23379557 DOI: 10.1134/s0006297913010045] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This mini-review summarizes literature and original data about the role of microtubules in interphase animal cells. Recent data have shown that functioning of microtubules is essential for such diverse phenomena as directional cell movements, distribution of organelles in the cytoplasm, and neuronal memory in the central nervous system. It is suggested that microtubules can act as an important regulatory system in eukaryotic cells. Possible mechanisms of these functions are discussed.
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Affiliation(s)
- J M Vasiliev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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3
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Lynch CD, Lazar AM, Iskratsch T, Zhang X, Sheetz MP. Endoplasmic spreading requires coalescence of vimentin intermediate filaments at force-bearing adhesions. Mol Biol Cell 2012; 24:21-30. [PMID: 23115305 PMCID: PMC3530776 DOI: 10.1091/mbc.e12-05-0377] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Interaction of vimentin filaments (vIFs) and force-bearing adhesions is essential for endoplasm spreading. For adhesions to be connected to a contractile network involved in endoplasm spreading, vIFs are needed. Thus endoplasm spreading and microtubule stabilization in the periphery require a multicomponent actin network anchored at adhesions. For cells to develop long-range forces and carry materials to the periphery, the microtubule and organelle-rich region at the center of the cell—the endoplasm—needs to extend to near the cell edge. Depletion of the actin cross-linking protein filamin A (FlnA) causes a collapse of the endoplasm into a sphere around the nucleus of fibroblasts and disruption of matrix adhesions, indicating that FlnA is involved in endoplasmic spreading and adhesion growth. Here, we report that treatment with the calpain inhibitor N-[N-(N-acetyl-l-leucyl)-l-leucyl]-l-norleucine (ALLN) restores endoplasmic spreading as well as focal adhesion (FA) growth on fibronectin-coated surfaces in a Fln-depleted background. Addback of calpain-uncleavable talin, not full-length talin, achieves a similar effect in Fln-depleted cells and indicates a crucial role for talin in endoplasmic spreading. Because FA maturation involves the vimentin intermediate filament (vIF) network, we also examined the role of vIFs in endoplasmic spreading. Wild-type cells expressing a vimentin variant incapable of polymerization exhibit deficient endoplasmic spreading as well as defects in FA growth. ALLN treatment restores FA growth despite the lack of vIFs but does not restore endoplasmic spreading, implying that vIFs are essential for endoplasm spreading. Consistent with that hypothesis, vIFs are always displaced from adhesions when the endoplasm does not spread. In Fln-depleted cells, vIFs extend beyond adhesions, nearly to the cell edge. Finally, inhibiting myosin II–mediated contraction blocks endoplasmic spreading and adhesion growth. Thus we propose a model in which myosin II–mediated forces and coalescence of vIFs at mature FAs are required for endoplasmic spreading.
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Affiliation(s)
- Christopher D Lynch
- Department of Biological Sciences, Columbia University, New York, NY 10027, USA
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4
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Abstract
Biomechanical signals such as cell shape and spreading play an important role in controlling stem cell commitment. Cell shape, adhesion and spreading are also affected by calreticulin, a multifunctional calcium-binding protein, which influences several cellular processes, including adipogenesis. Here we show that cytoskeletal disruption in mouse embryonic stem cells using cytochalasin D or nocodazole promotes adipogenesis. While cytochalasin D disrupts stress fibres and inhibits focal adhesion formation, nocodazole depolymerises microtubules and promotes focal adhesion formation. Furthermore, cytochalasin D increases the levels of both total and activated calcium/calmodulin-dependent protein kinase II, whereas nocodazole decreases it. Nevertheless, both treatments significantly increase the adipogenic potential of embryonic stem cells in vitro. Both cytochalasin D and nocodazole exposure caused cell rounding suggesting that it is cell shape that causes the switch towards the adipogenic programme. Calreticulin-containing embryonic stem cells, under baseline conditions, show low adipogenic potential, have low activity of signalling via calcium/calmodulin-dependent protein kinase II and display normal adhesive properties and cellular spreading in comparison to the highly adipogenic but poorly spread calreticulin-deficient ES cells. We conclude that forced cell rounding via cytoskeletal disruption overrides the effects of calreticulin, an ER chaperone, thus negatively regulating adipogenesis via focal adhesion-mediated cell spreading.
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5
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Binker MG, Zhao DY, Pang SJY, Harrison RE. Cytoplasmic linker protein-170 enhances spreading and phagocytosis in activated macrophages by stabilizing microtubules. THE JOURNAL OF IMMUNOLOGY 2007; 179:3780-91. [PMID: 17785815 DOI: 10.4049/jimmunol.179.6.3780] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Activation of macrophages causes increased cell spreading, increased secretion of cytokines and matrix metalloproteinases, and enhanced phagocytosis. The intracellular mechanisms driving the up-regulation of these activities have not been completely clarified. We observe that classical activation of murine resident peritoneal or RAW 264.7 macrophages with a combination of IFN-gamma and LPS induces an increase in stabilized cytoplasmic microtubules (MTs), measured with an anti-acetylated alpha-tubulin Ab. We examined the mechanism of this MT stabilization and find that macrophage activation causes redistribution of the MT plus-end tracking protein, cytoplasmic linker protein-170 (CLIP-170). CLIP-170 is localized at the distal plus-ends of MTs in resting macrophages, but accumulates along the length of MTs in IFN-gamma/LPS-activated cells. A direct involvement of CLIP-170 in MT stabilization has not been thoroughly established. In this study, we show that expression of a mutant CLIP-170 chimeric protein (dominant-negative CLIP-170-GFP), lacking the MT-binding domain, prevents MT stabilization in activated RAW 264.7 macrophages. Furthermore, we find enhanced CLIP-170 association with MTs and MT stabilization by treating resting macrophages with okadaic acid, implicating the protein phosphatase 2A in CLIP-170 binding and MT stabilization in RAW 264.7 cells. Finally, we observed enhanced cell spreading and phagocytosis in both IFN-gamma/LPS-activated and okadaic acid-treated resting RAW 264.7 cells, which are markedly reduced in activated cells expressing dominant-negative CLIP-170-GFP. These results identify CLIP-170 as a key regulator of MT stabilization and establish a prominent role for stabilized MTs in cell spreading and phagocytosis in activated macrophages.
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Affiliation(s)
- Marcelo G Binker
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, Ontario, Canada
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6
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Prager-Khoutorsky M, Goncharov I, Rabinkov A, Mirelman D, Geiger B, Bershadsky AD. Allicin inhibits cell polarization, migration and division via its direct effect on microtubules. ACTA ACUST UNITED AC 2007; 64:321-37. [PMID: 17323373 DOI: 10.1002/cm.20185] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Allicin (diallyl thiosulfinate) is a major biologically active component of garlic that is known to inhibit cell proliferation and induce apoptosis. The effects of allicin are attributed to its ability to react with thiol groups. However, the mechanism underlying the cytostatic activity of allicin, as well as the identity of the relevant subcellular targets, are not known. In the present study, we found that the effects of allicin on cell polarization, migration, and mitosis are similar to the effects of microtubule-depolymerizing drugs such as nocodazole. Moreover, treatment of cultured fibroblasts with micromolar doses of allicin results in microtubule depolymerization in cells within minutes of its application, without disrupting the actin cytoskeleton or inducing direct cytotoxic effects. Furthermore, allicin blocks the polymerization of pure tubulin in vitro in a concentration-dependent manner, suggesting that it acts directly on tubulin dimers. Sulfhydryl (SH)-reducing reagents such as 2-mercaptoethanol and dithiothreitol abolish the effect of allicin on microtubule polymerization. Thus, allicin is a potent microtubule-disrupting reagent interfering with tubulin polymerization by reaction with tubulin SH groups.
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7
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Jin T, Li J. Dynamitin controls Beta 2 integrin avidity by modulating cytoskeletal constraint on integrin molecules. J Biol Chem 2002; 277:32963-9. [PMID: 12082093 DOI: 10.1074/jbc.m201525200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dynamitin, a subunit of the microtubule-dependent motor complex, was implicated in cell adhesion by binding to MacMARCKS (Macrophage-enriched myristoylated alanine-rice C kinase substrate). However, how dynamitin is involved in cell adhesion is unclear despite the fact that both MacMARCKS and microtubules regulate beta(2) integrin activation. We report that dynamitin regulates beta(2) integrin avidity toward iC3b by modulating the lateral mobility of beta(2) integrin molecules. Using the single particle tracking method, we found that integrin molecular mobility in cells expressing the fusion protein CFP (cyan fluorescent protein)-dynamitin or CFP-MB (the MacMARCKS binding domain peptide of dynamitin) increased 6-fold over the control cells, suggesting that disturbing dynamitin function dramatically altered the cytoskeletal constraint on beta(2) integrin molecules. Further mechanistic studies revealed that overexpression of dynamitin stimulated the phosphorylation of endogenous MacMARCKS protein, which lead to the enhanced tyrosine phosphorylation of paxillin. This effect of dynamitin correlates with the observation that higher concentration of PKC inhibitor is required to block beta(2) integrin mobility in dynamitin-expressing cells. Although dynamitin acts at the point of MacMARCKS phosphorylation, it is upstream of RhoA, because its effect was blocked by RhoA inhibitor. Thus, we conclude that dynamitin is a part of the cytoskeletal constraint that locks beta(2) integrin in the inactive form.
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Affiliation(s)
- Tianquan Jin
- Department of Oral Biology, College of Dentistry, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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8
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Omelchenko T, Vasiliev JM, Gelfand IM, Feder HH, Bonder EM. Mechanisms of polarization of the shape of fibroblasts and epitheliocytes: Separation of the roles of microtubules and Rho-dependent actin-myosin contractility. Proc Natl Acad Sci U S A 2002; 99:10452-7. [PMID: 12149446 PMCID: PMC124937 DOI: 10.1073/pnas.152339899] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cultured fibroblasts possess a characteristic polarized phenotype manifested by an elongate cell body with an anterior lamella whose cell edge is divided into protrusion-forming and inactive zones. Disruption of the fibroblast microtubule cytoskeleton leads to an increase in Rho-dependent acto-myosin contractile activity and concomitant loss of structural polarity. The functional relationship of myosin-driven contractile activity to loss of fibroblast anterior-posterior polarity is unknown. To dissect the roles of microtubule assembly and of Rho-dependent contractility on structural polarization of cells, polarized fibroblasts and nonpolarized epitheliocytes were treated with the microtubule-depolymerizing drug, nocodazole, and/or the Rho kinase inhibitor, Y-27632. Fibroblasts incubated with Y-27632 increased their degree of polarization by developing a highly elongate cell body with multiple narrow processes extended from the edges of the cell. Treatment of fibroblasts with nocodazole, alone or in combination with Rho kinase inhibitor, produced discoid or polygonal cells having broad, flattened lamellae that did not form long lamellar extensions. Single cultured epitheliocytes of the IAR-2 line do not display anterior-posterior polarization. When treated with Y-27632, the cells acquired a polarized, elongate shape with narrow protrusions and wide lamellas. Nocodazole alone or in combination with Y-27632 did not change the discoid shape of epitheliocytes, however treatment with Y-27632 produced thinning of the lamellar cytoplasm. We conclude that microtubules provide the necessary framework for polarization of fibroblasts and epitheliocytes, whereas Rho-regulated contractility modulates the degree of polarization of fibroblasts and completely inhibits polarization in epitheliocytes.
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Affiliation(s)
- T Omelchenko
- Program in Cellular and Molecular Biodynamics and Department of Biological Sciences, Rutgers University, Newark, NJ 07102, USA
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9
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Zhou X, Li J, Kucik DF. The microtubule cytoskeleton participates in control of beta2 integrin avidity. J Biol Chem 2001; 276:44762-9. [PMID: 11579083 DOI: 10.1074/jbc.m104029200] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Leukocyte avidity is regulated by cytoskeletal constraints, which keep beta(2) integrins in an inactive mode. Releasing these constraints results in increased lateral mobility and clustering of integrins, effectively activating adhesion. At least part of the constraint on beta(2) integrins is due to actin; whether other cytoskeletal components are involved has not previously been investigated. Microtubules are a candidate for control of integrin rearrangement, because they modulate focal adhesions, which are sites of interaction between integrins and the cytoskeleton. Here we report that both depolymerization of microtubules by colchicine or nocodazole and stabilization of microtubules by taxol increased the lateral mobility of beta(2) integrins, activating adhesion. Increased integrin mobility was accompanied by an increase in tyrosine phosphorylation of paxillin, a biochemical event associated with activation of beta(2) integrins. Further, C3 exoenzyme, an inhibitor of Rho, blocked induction of integrin mobility by nocodazole, but not by taxol, suggesting that there are multiple microtubule-dependent pathways to integrin rearrangement, only some of which require Rho activity. Taken together, our data suggest that a dynamic microtubule system is required to regulate integrin-cytoskeleton interactions. Furthermore, these data demonstrate that microtubules participate in control of integrin rearrangement, one of the earliest steps in activation of integrin-mediated adhesion.
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Affiliation(s)
- X Zhou
- Department of Oral Biology, College of Dentistry, University of Illinois at Chicago, 60612, USA
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10
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Pletjushkina OJ, Rajfur Z, Pomorski P, Oliver TN, Vasiliev JM, Jacobson KA. Induction of cortical oscillations in spreading cells by depolymerization of microtubules. CELL MOTILITY AND THE CYTOSKELETON 2001; 48:235-44. [PMID: 11276073 DOI: 10.1002/cm.1012] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Actomyosin-based cortical contractility is a common feature of eukaryotic cells but the capability to produce rhythmic contractions is found in only a few types such as cardiomyocytes. Mechanisms responsible for the acquisition of this capability remain largely unknown. Rhythmic contractility can be induced in non-muscle cells by microtubule depolymerization. Spreading epithelial cells and fibroblasts in which microtubules were depolymerized with nocodazole or colcemid underwent rhythmic oscillations of the body that lasted for several hours before the cells acquired a stable, flattened shape. By contrast, control cells spread and flattened into discoid shapes in a smooth and regular manner. Quantitative analysis of the oscillations showed that they have a period of about 50 seconds. The kinase inhibitors, HA 1077 and H7, and the more specific rho-kinase inhibitor, Y 27632, caused the oscillations to immediately cease and the cells to become flat. Transient increases in cytoplasmic calcium preceded the contractile phase of the oscillations. Wrinkle formation by cells plated on elastic substrata indicated that the contractility of colcemid-treated cells increased in comparison to controls but was drastically decreased after HA 1077 addition. These data suggest that an intact microtubular system normally prevents pulsations by moderating excessive rho-mediated actin myosin contractility. Possible mechanistic interactions between rho-mediated and calcium activated contractile pathways that could produce morphological oscillations are discussed.
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Affiliation(s)
- O J Pletjushkina
- A. N. Belozersky Institute of Physical and Chemical Biology, Moscow State University, Vorobyevy Gory, Moscow, Russia
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11
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Yue L, Lu S, Garces J, Jin T, Li J. Protein kinase C-regulated dynamitin-macrophage-enriched myristoylated alanine-rice C kinase substrate interaction is involved in macrophage cell spreading. J Biol Chem 2000; 275:23948-56. [PMID: 10827182 DOI: 10.1074/jbc.m001845200] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Macrophage spreading requires the microtubule cytoskeleton and protein kinase C (PKC). The mechanism of involvement of the microtubules and PKC in this event is not fully understood. Dynamitin is a subunit of dynactin, which is important for linking the microtubule-dependent motor protein dynein to vesicle membranes. We report that dynamitin is a Ca(2+)/calmodulin-binding protein and that dynamitin binds directly to macrophage-enriched myristoylated alanine-rice C kinase substrate (MacMARCKS), a membrane-associated PKC substrate involved in macrophage spreading and integrin activation. Dynamitin was found to copurify with MacMARCKS both during MacMARCKS purification with conventional chromatography and during the immunoabsorption of MacMARCKS using anti-MacMARCKS antibody. Vice versa, MacMARCKS was also found to cosediment with the 20 S dynactin complex. We determined that the effector domain of MacMARCKS is required to interact with the N-terminal domain of dynamitin. MacMARCKS and dynamitin also partially colocalized at peripheral regions of macrophages and in the cell-cell border of 293 epithelial cells. Treatment with phorbol esters abolished this colocalization. Disrupting the interaction with a short peptide derived from the MacMARCKS-binding domain of dynamitin caused macrophages to spread and flatten. These data suggest that the dynamitin-MacMARCKS interaction is involved in cell spreading. Furthermore, the regulation of this interaction by PKC and Ca(2+)/calmodulin provides a possible regulatory mechanism for cell adhesion and spreading.
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Affiliation(s)
- L Yue
- Department of Oral Biology, College of Dentistry, the Cancer Center and Department of Microbiology & Immunology, College of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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12
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Abstract
Clustering of integrins into focal adhesions and focal complexes is regulated by the actin cytoskeleton. In turn, actin dynamics are governed by Rho family GTPases. Integrin-mediated adhesion activates these GTPases, triggering assembly of filopodia, lamellipodia and stress fibers. In the past few years, signaling pathways have begun to be identified that promote focal adhesion disassembly and integrin dispersal. Many of these pathways result in decreased myosin-mediated cell contractility.
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Affiliation(s)
- S M Schoenwaelder
- The Department of Cell Biology and Anatomy, 108 Taylor Hall, CB#7090, University of North Carolina, Chapel Hill, NC 27599, USA.
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13
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Small JV, Rottner K, Kaverina I, Anderson KI. Assembling an actin cytoskeleton for cell attachment and movement. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1404:271-81. [PMID: 9739149 DOI: 10.1016/s0167-4889(98)00080-9] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- J V Small
- Institute of Molecular Biology, Austrian Academy of Sciences, Billrothstrasse 11, A-5020 Salzburg, Austria
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14
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Kaverina I, Rottner K, Small JV. Targeting, capture, and stabilization of microtubules at early focal adhesions. J Biophys Biochem Cytol 1998; 142:181-90. [PMID: 9660872 PMCID: PMC2133026 DOI: 10.1083/jcb.142.1.181] [Citation(s) in RCA: 245] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
By co-injecting fluorescent tubulin and vinculin into fish fibroblasts we have revealed a "cross talk" between microtubules and early sites of substrate contact. This mutuality was first indicated by the targeting of vinculin-rich foci by microtubules during their growth towards the cell periphery. In addition to passing directly over contact sites, the ends of single microtubules could be observed to target several contacts in succession or the same contact repetitively, with intermittent withdrawals. Targeting sometimes involved side-stepping, or the major re-routing of a microtubule, indicative of a guided, rather than a random process. The paths that microtubules followed into contacts were unrelated to the orientation of stress fiber assemblies and targeting occurred also in mouse fibroblasts that lacked a system of intermediate filaments. Further experiments with microtubule inhibitors showed that adhesion foci can: (a) capture microtubules and stabilize them against disassembly by nocodazole; and (b), act as preferred sites of microtubule polymerization, during either early recovery from nocodazole, or brief treatment with taxol. From these and other findings we speculate that microtubules are guided into substrate contact sites and through the motor-dependent delivery of signaling molecules serve to modulate their development. It is further proposed this modulation provides the route whereby microtubules exert their influence on cell shape and polarity.
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Affiliation(s)
- I Kaverina
- Austrian Academy of Sciences, Institute of Molecular Biology, Department of Cell Biology, A-5020 Salzburg, Austria
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15
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Evans MD, Steele JG. Multiple attachment mechanisms of corneal epithelial cells to a polymer--cells can attach in the absence of exogenous adhesion proteins through a mechanism that requires microtubules. Exp Cell Res 1997; 233:88-98. [PMID: 9184079 DOI: 10.1006/excr.1997.3523] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The initial adhesion of epithelial cells is recognized as a critical determinant in the epithelialization of a polymer. Previously, the attachment of a variety of cell types to a polymer has been shown to be mediated by fibronectin and/or vitronectin that adsorb onto the polymer surface from the serum used to supplement the culture medium. Such an attachment reaction, dependent upon exogenous cell-adhesive proteins, is likely to involve the actin cytoskeleton and integrin receptors on the cell surface. In the current study, we have examined the attachment of recently isolated corneal epithelial cells to tissue culture polystyrene in the absence of such exogenous cell-adhesive proteins. Under these circumstances, there is an alternative mechanism of attachment operative between corneal epithelial cells and the polymer surface which is essentially independent of the adsorption of serum-derived fibronectin and vitronectin. This is an unusual phenomenon not previously observed with other normal cell types. The presence of cycloheximide inhibited this alternative attachment mechanism in corneal epithelial cells, indicating the role of newly synthesized proteins in this reaction. Additionally, we found that cell attachment to the polymer surface in the absence of cell-adhesive proteins was substantially inhibited by the presence of demecolcine, but not by cytochalasin B, thereby demonstrating the involvement of microtubules rather than actin microfilaments in this reaction. In the presence of serum-derived fibronectin and vitronectin, the attachment of corneal epithelial cells to a polymer may involve dual attachment mechanisms.
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Affiliation(s)
- M D Evans
- CSIRO Division of Biomolecular Engineering, Sydney, Australia.
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16
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Svitkina TM, Rovensky YA, Bershadsky AD, Vasiliev JM. Transverse pattern of microfilament bundles induced in epitheliocytes by cylindrical substrata. J Cell Sci 1995; 108 ( Pt 2):735-45. [PMID: 7769015 DOI: 10.1242/jcs.108.2.735] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cylindrical culture substrata are known to induced longitudinal orientation of polarized fibroblasts and corresponding alignment of actin microfilament bundles in these cells. We studied microfilament bundle distribution in two cell types, fibroblasts and epitheliocytes, spread on two kinds of anisotropic substrata, quartz glass cylinders with a diameter 32 microns and narrow (25-40 microns wide) flat glass adhesive strips with non-adhesive borders. Rat embryo and human diploid fibroblasts, as expected, formed predominantly longitudinally aligned bundles on both substrata. In contrast, transverse bundles on cylinders and randomly oriented bundles on flat strips were formed in IAR-2 and MDCK epithelial cells. We interpret these data as showing that the epitheliocyte attempts to override the guiding influence of anisotropic substrata. The microfilament bundle pattern on cylinders depends on the integrity of the microtubules. Colcemid-induced microtubule depolymerization caused formation of longitudinal as well as transverse bundles both in fibroblasts and epitheliocytes, thus diminishing the differences in microfilament bundle patterns in two cell types. These results show that microtubules control the cell-type-specific distribution of microfilament bundles both in polarized fibroblasts and in discoid epitheliocytes. However, the results of this control are opposite: microtubules enhance cell polarization in fibroblasts, but prevent it in epithelial cells.
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Affiliation(s)
- T M Svitkina
- Belozersky Institute of Physical and Chemical Biology, Moscow State University, Russia
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17
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Oakley C, Brunette DM. Topographic compensation: guidance and directed locomotion of fibroblasts on grooved micromachined substrata in the absence of microtubules. CELL MOTILITY AND THE CYTOSKELETON 1995; 31:45-58. [PMID: 7553901 DOI: 10.1002/cm.970310106] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Fibroblasts cultured on grooved substrata align themselves and migrate in the direction of the grooves, a phenomenon called contact guidance. Microtubules have been deemed important for cell polarization, directed locomotion, and contact guidance. Because microtubules were the first cytoskeletal element to align with the grooves when fibroblasts spread on grooved substrata, we investigated the consequences of eliminating the influence of microtubules by seeding fibroblasts onto smooth and grooved micromachined substrata in the presence of colcemid. Fibroblasts were examined by time-lapse cinematography and epifluorescence or confocal microscopy to determine cell shape and orientation and the distribution of cytoskeletal or associated elements including actin filaments, vinculin, intermediate filaments, microtubules, and kinesin. As expected, cells spreading on smooth surfaces in the presence of colcemid did not polarize or locomote. Surprisingly however, by 24 hours, cells spread on grooves in the presence of colcemid were morphologically indistinguishable from controls spread on grooves. Both groups were aligned and polarized with the direction of the grooves and demonstrated directional locomotion along the grooves. In the absence of microtubules, kinesin localized to some of the aligned stress fibers and to leading edges of cells spreading on grooves. The grooved substratum compensated for the microtubule deficiency by organizing and maintaining an aligned actin filament framework. Thus, microtubules are not required to establish or maintain stable, polarized cell shapes or directed locomotion, provided an alternate oriented cytoskeletal component is available.
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Affiliation(s)
- C Oakley
- Department of Oral Biology, University of British Columbia, Vancouver, Canada
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Brown DA, Warn RM. Primary and secondary chick heart fibroblasts: fast and slow-moving cells show no significant difference in microtubule dynamics. CELL MOTILITY AND THE CYTOSKELETON 1993; 24:233-44. [PMID: 8477456 DOI: 10.1002/cm.970240404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Highly motile chick heart fibroblasts in primary culture (1 degree CHFs) gradually convert into much slower-moving secondary (2 degrees) cells. The polarized movement of the latter, but not the former, cell type has been found to be dependent on an intact microtubule (MT) network [Middleton et al., 1989, J. Cell Sci. 94:25-32]. To investigate the comparative stability of the MT networks of 1 degree s and 2 degrees s, turnover was investigated by microinjection of biotin-labeled brain tubulin to act as a reporter. MTs in both cell types were found to be very dynamic, with the MT networks effectively disassembled by about 30 min in 1 degree CHFs and 60 min in 2 degrees CHFs, with mainly MT fragments remaining beyond these times. All MTs and fragments were found to have turned over by 1 h in 1 degree CHFs and 80 min in 2 degrees s. Because 2 degrees CHFs were found to be on average six times larger than 1 degree s, the difference in MT turnover time was considered largely due to the size difference. For both 1 degree and 2 degrees cells, the more slowly turning over MTs were generally curly and perinuclear in distribution, resembling stable MTs in other systems, but they appeared significantly earlier in CHFs. However, no discrete subpopulations of slower turning over MTs were found to be associated with either the leading edges or the processes of either cell type. In addition, no major differences were identified in the patterns of modified alpha-tubulin along the MTs or of MT cold or drug stability. It is concluded that MTs do not have a direct structural or skeletal function in maintaining a polarized 2 degrees CHF cell shape, but rather play an ancillary role.
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Affiliation(s)
- D A Brown
- School of Biological Sciences, University of East Anglia, Norwich, United Kingdom
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Rovensky YA, Bershadsky AD, Givargizov EI, Obolenskaya LN, Vasiliev JM. Spreading of mouse fibroblasts on the substrate with multiple spikes. Exp Cell Res 1991; 197:107-12. [PMID: 1915657 DOI: 10.1016/0014-4827(91)90486-e] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Mouse embryo fibroblasts were cultivated on special substrates with discontinuous surfaces. The substrates were silicon plates with multiple vertical (65-90 microns height) spike-like silicon microcrystals evenly distributed on the plate surfaces. It was shown that the cells were successfully spread and flattened on these substrates. The spread cells formed several discrete attachment zones at the tops and side surfaces of the spikes; these zones were separated from one another by distances considerably greater than the diameter of the unspread cell. At early stages of spreading the unspread cells attached to the tops of single spikes and extended long filopodia attached to the distant spikes. At later stages the lamellae were formed between the filopodia: probably these filopodia served as guidelines for extension of lamellae and progressive cell spreading. These experiments demonstrated that continuity of substrate surface is not a necessary condition for advanced cell spreading.
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Affiliation(s)
- Y A Rovensky
- Cancer Research Center, Academy of Medical Sciences of the USSR, Moscow
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20
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Cytoskeletal organization and cell organelle transport in basal epithelial cells of the freshwater sponge Spongilla lacustris. Cell Tissue Res 1990. [DOI: 10.1007/bf00329447] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Conrad PA, Nederlof MA, Herman IM, Taylor DL. Correlated distribution of actin, myosin, and microtubules at the leading edge of migrating Swiss 3T3 fibroblasts. CELL MOTILITY AND THE CYTOSKELETON 1989; 14:527-43. [PMID: 2696599 DOI: 10.1002/cm.970140410] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The formation of lamellipodia in migrating cells involves dynamic processes that occur in a cyclic manner as the leading edge of a cell slowly advances. We used video-enhanced contrast microscopy (VEC) to monitor the motile behavior of cells to classify protrusions into the temporal stages of initial and established protrusions (Fisher et al.: Cell Motility and the Cytoskeleton 11:235-247, 1988), and to monitor the fixation of cells. Multiple parameter fluorescence imaging methods (DeBiasio et al.: Journal of Cell Biology 105:1613-1622, 1987; Waggoner et al.: Methods in Cell Biology, Vol. 30, Part B, pp. 449-478, 1989) were then used to determine and to map accurately the distributions of actin, myosin and microtubules in specific types of protrusions. Initial protrusions exhibited no substructure as evidenced by VEC and actin was diffusely arranged, while myosin and microtubules were absent. Newly established protrusions contained diffuse actin as well as actin in microspikes. There was a delay in the appearance of myosin into established protrusions relative to the presence of actin. Microtubules were found in established protrusions after myosin was detected, and they were oriented parallel to the direction of migration. Actin and myosin were also localized in fibers transverse to the direction of migration at the base of initial and established protrusions. Image analysis was used to quantify the orientation of actin fibers relative to the leading edge of motile cells. The combined use of VEC, multiple parameter immunofluorescence, and image analysis should have a major impact on defining complex relationships within cells.
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Affiliation(s)
- P A Conrad
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213
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22
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Mareel MM, De Mets M. Effect of microtubule inhibitors on invasion and on related activities of tumor cells. INTERNATIONAL REVIEW OF CYTOLOGY 1984; 90:125-68. [PMID: 6389412 DOI: 10.1016/s0074-7696(08)61489-8] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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23
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24
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Domnina LV, Gelfand VI, Ivanova OY, Leonova EV, Pletjushkina OY, Vasiliev JM, Gelfand IM. Effects of small doses of cytochalasins on fibroblasts: preferential changes of active edges and focal contacts. Proc Natl Acad Sci U S A 1982; 79:7754-7. [PMID: 6961447 PMCID: PMC347426 DOI: 10.1073/pnas.79.24.7754] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The effects of low doses of cytochalasin B (2 micrograms/ml) and cytochalasin D (0.2 microgram/ml) on the spreading of normal mouse fibroblasts in culture were investigated to find out which components of cell-substrate interactions are most sensitive to alterations of the state of actin cytoskeleton. Cytochalasin B disorganized the cortical layer of actin microfilaments and caused partial or complete disappearance of microfilament bundles; focal contacts with the substrate seen by interference-reflection microscopy also disappeared. Diffuse close contacts were apparently insensitive to cytochalasin B. Low doses of cytochalasin B did not inhibit the outgrowth and maintenance of lamellas at the cell periphery. However, in contrast to controls, these lamellas had no distal zones with convex outer edges and ruffles at the upper surfaces. The disappearance of these ruffling active edges was accompanied by loss of the ability to clear the surface of the lamellas from the concanavalin A receptors crosslinked by the corresponding ligand. The effects of cytochalasin D were similar to those of cytochalasin B. Thus, ruffling active edges and focal contacts can be regarded as specialized parts of lamellas with increased sensitivity to cytochalasins; the presence of ruffling active edges is essential for the initiation of centripetal movement of the patches of crosslinked surface receptors.
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25
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Udoh P, Derby A. The effect of the substrate on tadpole tailfin epidermal cells in vitro. ACTA ACUST UNITED AC 1982. [DOI: 10.1002/jez.1402190109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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26
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Englander LL, Malech HL. Abnormal movement of polymorphonuclear neutrophils in the Immotile Cilia Syndrome. Cinemicrographic analysis. Exp Cell Res 1981; 135:468-72. [PMID: 6975720 DOI: 10.1016/0014-4827(81)90193-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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27
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Tsuchiya W, Okada Y, Yano J, Inouye A, Sasaki S, Doida Y. Effects of cytochalasin B and local anesthetics on electrical and morphological properties in L cells. Exp Cell Res 1981; 133:83-92. [PMID: 7238599 DOI: 10.1016/0014-4827(81)90359-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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28
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Dahl JE, Stene T, Koppang HS, Koppang R, Stokke T. beta-Lumicolchicine as a tool to elucidate microtubular function in dentinogenesis. Acta Odontol Scand 1981; 39:195-200. [PMID: 6948490 DOI: 10.3109/00016358109162280] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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29
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Bliokh ZL, Domnina LV, Ivanova OY, Pletjushkina OY, Svitkina TM, Smolyaninov VA, Vasiliev JM, Gelfand IM. Spreading of fibroblasts in medium containing cytochalasin B: formation of lamellar cytoplasm as a combination of several functional different processes. Proc Natl Acad Sci U S A 1980; 77:5919-22. [PMID: 6934523 PMCID: PMC350183 DOI: 10.1073/pnas.77.10.5919] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Normal cultured mouse fibroblasts spreading on solid substrate extend and attach numerous pseudopods; lamellar cytoplasm is eventually formed from the attached pseudopods. Fibroblasts spreading in the presence of cytochasin B (CB) from de novo a system of arbor-like branched processes rather than lamellar cytoplasm. The growing and fully formed arbor-like processes, in contrast to normal lamellar cytoplasm, have low contractility and are unable to clear patched concanavalin A receptors from their surfaces; their attachement sites are not associated with microfilament bundles. The cells spreading in medium containing CB and Colcemid do not form well-organized branched structures but extend and attach numerous unstable pseudopods. It is suggested that normal formation of lamellar cytoplasm can be regarded as a combination of several functionally different processes: (a) of rudimentary pseudopodial reactions resistant to CB and Colcemid; (b) of CB-sensitive lamellization; and (c) of Colcemid-sensitive stabilization.
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30
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Ivanova OY, Svitkina TM, Vasiliev JM, Gelfand IM. Effect of colcemid on the distribution of pseudopodial activity in fibroblasts. Microtubule-independent stabilization of cell surface. Exp Cell Res 1980; 128:457-61. [PMID: 7409000 DOI: 10.1016/0014-4827(80)90081-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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31
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Pearlstein E, Gold LI, Garcia-Pardo A. Fibronectin: a review of its structure and biological activity. Mol Cell Biochem 1980; 29:103-28. [PMID: 6988694 DOI: 10.1007/bf00220304] [Citation(s) in RCA: 286] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
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32
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Stern CD. A re-examination of mitotic activity in the early chick embryo. ANATOMY AND EMBRYOLOGY 1979; 156:319-29. [PMID: 475001 DOI: 10.1007/bf00299630] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
As a result of extensive mitotic index analysis in colchicine-arrested chick embryos during gastrulation, it was ascertained that the primitive streak is a region of elevated mitotic index as compared to the surrounding tissue. Along the cephalo-caudal axis, the embryo displays two large peaks of mitotic index, one at the posterior end of the primitive streak and the other just anterior to Hensen's node. The length of the various phases of the mitotic period was determined in vitro by time-lapse filming, and the colchicine-arrested mitotic indices in vivo and in vitro were determined and compared for various regions. Some observations regarding the orientation of mitotic spindles and abnormal mitosis in vitro are also included, and the relevance of the above observations to early embryonic development is discussed.
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33
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Armstrong MT, Armstrong PB. The effects of antimicrotubule agents on cell motility in fibroblast aggregates. Exp Cell Res 1979; 120:359-64. [PMID: 436963 DOI: 10.1016/0014-4827(79)90395-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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34
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Allred LE. Cloning of normal and transformed cells on plastic films. Methods Cell Biol 1978; 20:237-45. [PMID: 692431 DOI: 10.1016/s0091-679x(08)62021-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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35
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Grinnell F. Cellular adhesiveness and extracellular substrata. INTERNATIONAL REVIEW OF CYTOLOGY 1978; 53:65-144. [PMID: 208994 DOI: 10.1016/s0074-7696(08)62241-x] [Citation(s) in RCA: 664] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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36
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Biochemical Determinants of Cell Adhesion. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/s0070-2161(08)60752-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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37
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Vasiliev JM, Gelfand IM. Mechanisms of morphogenesis in cell cultures. INTERNATIONAL REVIEW OF CYTOLOGY 1977; 50:159-274. [PMID: 332655 DOI: 10.1016/s0074-7696(08)60099-6] [Citation(s) in RCA: 88] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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