1
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Berg C, Sieber M, Sun J. Finishing the egg. Genetics 2024; 226:iyad183. [PMID: 38000906 PMCID: PMC10763546 DOI: 10.1093/genetics/iyad183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/27/2023] [Indexed: 11/26/2023] Open
Abstract
Gamete development is a fundamental process that is highly conserved from early eukaryotes to mammals. As germ cells develop, they must coordinate a dynamic series of cellular processes that support growth, cell specification, patterning, the loading of maternal factors (RNAs, proteins, and nutrients), differentiation of structures to enable fertilization and ensure embryonic survival, and other processes that make a functional oocyte. To achieve these goals, germ cells integrate a complex milieu of environmental and developmental signals to produce fertilizable eggs. Over the past 50 years, Drosophila oogenesis has risen to the forefront as a system to interrogate the sophisticated mechanisms that drive oocyte development. Studies in Drosophila have defined mechanisms in germ cells that control meiosis, protect genome integrity, facilitate mRNA trafficking, and support the maternal loading of nutrients. Work in this system has provided key insights into the mechanisms that establish egg chamber polarity and patterning as well as the mechanisms that drive ovulation and egg activation. Using the power of Drosophila genetics, the field has begun to define the molecular mechanisms that coordinate environmental stresses and nutrient availability with oocyte development. Importantly, the majority of these reproductive mechanisms are highly conserved throughout evolution, and many play critical roles in the development of somatic tissues as well. In this chapter, we summarize the recent progress in several key areas that impact egg chamber development and ovulation. First, we discuss the mechanisms that drive nutrient storage and trafficking during oocyte maturation and vitellogenesis. Second, we examine the processes that regulate follicle cell patterning and how that patterning impacts the construction of the egg shell and the establishment of embryonic polarity. Finally, we examine regulatory factors that control ovulation, egg activation, and successful fertilization.
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Affiliation(s)
- Celeste Berg
- Department of Genome Sciences, University of Washington, Seattle, WA 98195-5065USA
| | - Matthew Sieber
- Department of Physiology, UT Southwestern Medical Center, Dallas, TX 75390USA
| | - Jianjun Sun
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT 06269USA
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2
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Quast T, Zölzer K, Guu D, Alvarez L, Küsters C, Kiermaier E, Kaupp UB, Kolanus W. A Stable Chemokine Gradient Controls Directional Persistence of Migrating Dendritic Cells. Front Cell Dev Biol 2022; 10:943041. [PMID: 36016652 PMCID: PMC9395945 DOI: 10.3389/fcell.2022.943041] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
Navigation of dendritic cells (DCs) from the site of infection to lymphoid organs is guided by concentration gradients of CCR7 ligands. How cells interpret chemokine gradients and how they couple directional sensing to polarization and persistent chemotaxis has remained largely elusive. Previous experimental systems were limited in the ability to control fast de novo formation of the final gradient slope, long-lasting stability of the gradient and to expose cells to dynamic stimulation. Here, we used a combination of microfluidics and quantitative in vitro live cell imaging to elucidate the chemotactic sensing strategy of DCs. The microfluidic approach allows us to generate soluble gradients with high spatio-temporal precision and to analyze actin dynamics, cell polarization, and persistent directional migration in both static and dynamic environments. We demonstrate that directional persistence of DC migration requires steady-state characteristics of the soluble gradient instead of temporally rising CCL19 concentration, implying that spatial sensing mechanisms control chemotaxis of DCs. Kymograph analysis of actin dynamics revealed that the presence of the CCL19 gradient is essential to stabilize leading edge protrusions in DCs and to determine directionality, since both cytoskeletal polarization and persistent chemotaxis are abrogated in the range of seconds when steady-state gradients are perturbed. In contrast to Dictyostelium amoeba, DCs are unable to decode oscillatory stimulation of soluble chemokine traveling waves into a directional response toward the wave source. These findings are consistent with the notion that DCs do not employ adaptive temporal sensing strategies that discriminate temporally increasing and decreasing chemoattractant concentrations in our setting. Taken together, in our experimental system DCs do not depend on increasing absolute chemokine concentration over time to induce persistent migration and do not integrate oscillatory stimulation. The observed capability of DCs to migrate with high directional persistence in stable gradients but not when subjected to periodic temporal cues, identifies spatial sensing as a key requirement for persistent chemotaxis of DCs.
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Affiliation(s)
- Thomas Quast
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Karolin Zölzer
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Donald Guu
- Molecular Sensory Systems, Max Planck Institute for Neurobiology of Behavior—Caesar, Bonn, Germany
| | - Luis Alvarez
- Molecular Sensory Systems, Max Planck Institute for Neurobiology of Behavior—Caesar, Bonn, Germany
| | - Carsten Küsters
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - Eva Kiermaier
- Immune and Tumor Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
| | - U. Benjamin Kaupp
- Molecular Sensory Systems, Max Planck Institute for Neurobiology of Behavior—Caesar, Bonn, Germany
| | - Waldemar Kolanus
- Molecular Immunology and Cell Biology, Life and Medical Sciences Institute (LIMES), University of Bonn, Bonn, Germany
- *Correspondence: Waldemar Kolanus,
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3
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Modeling protein dynamics in Caenorhabditis elegans embryos reveals that the PLK-1 gradient relies on weakly coupled reaction-diffusion mechanisms. Proc Natl Acad Sci U S A 2022; 119:e2114205119. [PMID: 35259017 PMCID: PMC8931239 DOI: 10.1073/pnas.2114205119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Intracellular gradients have essential roles in cell and developmental biology, but their formation is not fully understood. We have developed a computational approach facilitating interpretation of protein dynamics and gradient formation. We have combined this computational approach with experiments to understand how Polo-Like Kinase 1 (PLK-1) forms a cytoplasmic gradient in Caenorhabditis elegans embryos. Although the PLK-1 gradient depends on the Muscle EXcess-5/6 (MEX-5/6) proteins, we reveal differences in PLK-1 and MEX-5 gradient formation that can be explained by a model with two components, PLK-1 bound to MEX-5 and unbound PLK-1. Our combined approach suggests that a weak coupling between PLK-1 and MEX-5 reaction–diffusion mechanisms dictates the dynamic exchange of PLK-1 with the cytoplasm, explaining PLK-1 high diffusivity and smooth gradient. Protein gradients have fundamental roles in cell and developmental biology. In the one-cell Caenorhabditis elegans embryo, the mitotic Polo-Like Kinase 1 (PLK-1) forms an anterior-rich cytoplasmic gradient, which is crucial for asymmetric cell division and embryonic development. The PLK-1 gradient depends on the RNA-binding Muscle-EXcess-5 protein (MEX-5), whose slow-diffusing complexes accumulate in the anterior via a reaction–diffusion mechanism. Here, we combine experiments and a computational approach to investigate the dynamics of PLK-1 gradient formation. We find that the gradient of PLK-1 initiates later, is less steep, and forms with slower dynamics than does the MEX-5 gradient. The data show that PLK-1 diffuses faster than MEX-5 in both anterior and posterior cytoplasmic regions. Our simulations suggest that binding to slow-diffusing MEX-5 is required for PLK-1 gradient formation, but that a significant fraction of unbound PLK-1 is necessary to justify the different gradient dynamics. We provide a computational tool able to predict gradient establishment prior to cell division and show that a two-component, bound and unbound, model of PLK-1 dynamics recapitulates the experimental observations.
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4
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Lu P, Lu Y. Born to Run? Diverse Modes of Epithelial Migration. Front Cell Dev Biol 2021; 9:704939. [PMID: 34540829 PMCID: PMC8448196 DOI: 10.3389/fcell.2021.704939] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 07/20/2021] [Indexed: 12/15/2022] Open
Abstract
Bundled with various kinds of adhesion molecules and anchored to the basement membrane, the epithelium has historically been considered as an immotile tissue and, to migrate, it first needs to undergo epithelial-mesenchymal transition (EMT). Since its initial description more than half a century ago, the EMT process has fascinated generations of developmental biologists and, more recently, cancer biologists as it is believed to be essential for not only embryonic development, organ formation, but cancer metastasis. However, recent progress shows that epithelium is much more motile than previously realized. Here, we examine the emerging themes in epithelial collective migration and how this has impacted our understanding of EMT.
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Affiliation(s)
- Pengfei Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Yunzhe Lu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
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5
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Bischoff MC, Bogdan S. Collective cell migration driven by filopodia-New insights from the social behavior of myotubes. Bioessays 2021; 43:e2100124. [PMID: 34480489 DOI: 10.1002/bies.202100124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 01/12/2023]
Abstract
Collective migration is a key process that is critical during development, as well as in physiological and pathophysiological processes including tissue repair, wound healing and cancer. Studies in genetic model organisms have made important contributions to our current understanding of the mechanisms that shape cells into different tissues during morphogenesis. Recent advances in high-resolution and live-cell-imaging techniques provided new insights into the social behavior of cells based on careful visual observations within the context of a living tissue. In this review, we will compare Drosophila testis nascent myotube migration with established in vivo model systems, elucidate similarities, new features and principles in collective cell migration.
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Affiliation(s)
- Maik C Bischoff
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, Marburg, Germany
| | - Sven Bogdan
- Institute of Physiology and Pathophysiology, Department of Molecular Cell Physiology, Philipps-University Marburg, Marburg, Germany
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6
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Dai W, Guo X, Cao Y, Mondo JA, Campanale JP, Montell BJ, Burrous H, Streichan S, Gov N, Rappel WJ, Montell DJ. Tissue topography steers migrating Drosophila border cells. Science 2021; 370:987-990. [PMID: 33214282 DOI: 10.1126/science.aaz4741] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 05/11/2020] [Accepted: 09/28/2020] [Indexed: 12/16/2022]
Abstract
Moving cells can sense and respond to physical features of the microenvironment; however, in vivo, the significance of tissue topography is mostly unknown. Here, we used Drosophila border cells, an established model for in vivo cell migration, to study how chemical and physical information influences path selection. Although chemical cues were thought to be sufficient, live imaging, genetics, modeling, and simulations show that microtopography is also important. Chemoattractants promote predominantly posterior movement, whereas tissue architecture presents orthogonal information, a path of least resistance concentrated near the center of the egg chamber. E-cadherin supplies a permissive haptotactic cue. Our results provide insight into how cells integrate and prioritize topographical, adhesive, and chemoattractant cues to choose one path among many.
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Affiliation(s)
- Wei Dai
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Xiaoran Guo
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Yuansheng Cao
- Department of Physics, University of California, San Diego, CA 92093, USA
| | - James A Mondo
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Joseph P Campanale
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | | | - Haley Burrous
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA
| | - Sebastian Streichan
- Department of Physics, University of California, Santa Barbara, CA 93106, USA
| | - Nir Gov
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Wouter-Jan Rappel
- Department of Physics, University of California, San Diego, CA 92093, USA
| | - Denise J Montell
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106, USA.
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7
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All Roads Lead to Directional Cell Migration. Trends Cell Biol 2020; 30:852-868. [PMID: 32873438 DOI: 10.1016/j.tcb.2020.08.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/30/2020] [Accepted: 08/04/2020] [Indexed: 01/17/2023]
Abstract
Directional cell migration normally relies on a variety of external signals, such as chemical, mechanical, or electrical, which instruct cells in which direction to move. Many of the major molecular and physical effects derived from these cues are now understood, leading to questions about whether directional cell migration is alike or distinct under these different signals, and how cells might be directed by multiple simultaneous cues, which would be expected in complex in vivo environments. In this review, we compare how different stimuli are spatially distributed, often as gradients, to direct cell movement and the mechanisms by which they steer cells. A comparison of the downstream effectors of directional cues suggests that different external signals regulate a common set of components: small GTPases and the actin cytoskeleton, which implies that the mechanisms downstream of different signals are likely to be closely related and underlies the idea that cell migration operates by a common set of physical principles, irrespective of the input.
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8
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Dissemination of Ras V12-transformed cells requires the mechanosensitive channel Piezo. Nat Commun 2020; 11:3568. [PMID: 32678085 PMCID: PMC7366633 DOI: 10.1038/s41467-020-17341-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 06/24/2020] [Indexed: 12/31/2022] Open
Abstract
Dissemination of transformed cells is a key process in metastasis. Despite its importance, how transformed cells disseminate from an intact tissue and enter the circulation is poorly understood. Here, we use a fully developed tissue, Drosophila midgut, and describe the morphologically distinct steps and the cellular events occurring over the course of RasV12-transformed cell dissemination. Notably, RasV12-transformed cells formed the Actin- and Cortactin-rich invasive protrusions that were important for breaching the extracellular matrix (ECM) and visceral muscle. Furthermore, we uncovered the essential roles of the mechanosensory channel Piezo in orchestrating dissemination of RasV12-transformed cells. Collectively, our study establishes an in vivo model for studying how transformed cells migrate out from a complex tissue and provides unique insights into the roles of Piezo in invasive cell behavior. Drosophila tumours can be utilised to study the mechanisms of cell dissemination. Here, the authors use Drosophila midgut to examine the course of RasV12-transformed cell dissemination from midgut into circulation, which requires the actions of invasive protrusions and the mechanosensitive channel Piezo.
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9
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Kenwrick K, Mukherjee A, Renault AD. Hmgcr promotes a long-range signal to attract Drosophila germ cells independently of Hedgehog. J Cell Sci 2019; 132:jcs.232637. [PMID: 31719159 DOI: 10.1242/jcs.232637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 10/31/2019] [Indexed: 11/20/2022] Open
Abstract
During development, many cell types migrate along stereotyped routes determined through deployment of cell surface or secreted guidance molecules. Although we know the identity of many of these molecules, the distances over which they natively operate can be difficult to determine. Here, we have quantified the range of an attractive signal for the migration of Drosophila germ cells. Their migration is guided by an attractive signal generated by the expression of genes in the 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (Hmgcr) pathway, and by a repulsive signal generated by the expression of Wunens. We demonstrate that the attractive signal downstream of Hmgcr is cell-contact independent and acts at long range, the extent of which depends on Hmgcr levels. This range would be sufficient to reach all of the germ cells for their entire migration. Furthermore, Hmgcr-mediated attraction does not require Wunens but can operate simultaneously with Wunen-mediated repulsion. Finally, several papers posit Hedgehog (Hh) as being the germ cell attractant downstream of H mgcr Here, we provide evidence that this is not the case.
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Affiliation(s)
- Kim Kenwrick
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Amrita Mukherjee
- Department of Zoology, University of Cambridge, Downing St, Cambridge CB2 3EJ, UK
| | - Andrew D Renault
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK
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10
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Comai G, Heude E, Mella S, Paisant S, Pala F, Gallardo M, Langa F, Kardon G, Gopalakrishnan S, Tajbakhsh S. A distinct cardiopharyngeal mesoderm genetic hierarchy establishes antero-posterior patterning of esophagus striated muscle. eLife 2019; 8:e47460. [PMID: 31535973 PMCID: PMC6752947 DOI: 10.7554/elife.47460] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 08/27/2019] [Indexed: 02/06/2023] Open
Abstract
In most vertebrates, the upper digestive tract is composed of muscularized jaws linked to the esophagus that permits food ingestion and swallowing. Masticatory and esophagus striated muscles (ESM) share a common cardiopharyngeal mesoderm (CPM) origin, however ESM are unusual among striated muscles as they are established in the absence of a primary skeletal muscle scaffold. Using mouse chimeras, we show that the transcription factors Tbx1 and Isl1 are required cell-autonomously for myogenic specification of ESM progenitors. Further, genetic loss-of-function and pharmacological studies point to MET/HGF signaling for antero-posterior migration of esophagus muscle progenitors, where Hgf ligand is expressed in adjacent smooth muscle cells. These observations highlight the functional relevance of a smooth and striated muscle progenitor dialogue for ESM patterning. Our findings establish a Tbx1-Isl1-Met genetic hierarchy that uniquely regulates esophagus myogenesis and identify distinct genetic signatures that can be used as framework to interpret pathologies arising within CPM derivatives.
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Affiliation(s)
- Glenda Comai
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
| | - Eglantine Heude
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
- Department Adaptation du VivantCNRS/MNHN UMR 7221, Muséum national d’Histoire naturelleParisFrance
| | - Sebastian Mella
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
| | - Sylvain Paisant
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
| | - Francesca Pala
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
- Laboratory of Clinical Immunology and Microbiology (LCIM)National Institutes of HealthBethesdaUnited States
| | - Mirialys Gallardo
- Department of Human GeneticsUniversity of UtahSalt Lake CityUnited States
| | - Francina Langa
- Mouse Genetics Engineering CenterInstitut PasteurParisFrance
| | - Gabrielle Kardon
- Department of Human GeneticsUniversity of UtahSalt Lake CityUnited States
| | - Swetha Gopalakrishnan
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
- Institute of Biotechnology, HiLIFEUniversity of HelsinkiHelsinkiFinland
| | - Shahragim Tajbakhsh
- Department of Developmental and Stem Cell BiologyInstitut PasteurParisFrance
- CNRS UMR 3738ParisFrance
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11
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Du L, Sohr A, Yan G, Roy S. Feedback regulation of cytoneme-mediated transport shapes a tissue-specific FGF morphogen gradient. eLife 2018; 7:38137. [PMID: 30328809 PMCID: PMC6224196 DOI: 10.7554/elife.38137] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/16/2018] [Indexed: 12/22/2022] Open
Abstract
Gradients of signaling proteins are essential for inducing tissue morphogenesis. However, mechanisms of gradient formation remain controversial. Here we characterized the distribution of fluorescently-tagged signaling proteins, FGF and FGFR, expressed at physiological levels from the genomic knock-in alleles in Drosophila. FGF produced in the larval wing imaginal-disc moves to the air-sac-primordium (ASP) through FGFR-containing cytonemes that extend from the ASP to contact the wing-disc source. The number of FGF-receiving cytonemes extended by ASP cells decreases gradually with increasing distance from the source, generating a recipient-specific FGF gradient. Acting as a morphogen in the ASP, FGF activates concentration-dependent gene expression, inducing pointed-P1 at higher and cut at lower levels. The transcription-factors Pointed-P1 and Cut antagonize each other and differentially regulate formation of FGFR-containing cytonemes, creating regions with higher-to-lower numbers of FGF-receiving cytonemes. These results reveal a robust mechanism where morphogens self-generate precise tissue-specific gradient contours through feedback regulation of cytoneme-mediated dispersion. When an embryo develops, its cells must work together and ‘talk’ with each other so they can build the tissues and organs of the body. A cell can communicate with its neighbors by producing a signal, also known as a morphogen, which will tell the receiving cells what to do. Once outside the cell, a morphogen spreads through the surrounding tissue and forms a gradient: there is more of the molecule closer to the signaling cells and less further away. The cells that receive the message respond differently depending on how much morphogen they get, and therefore on where they are placed in the embryo. How morphogens move in tissues to create gradients is still poorly understood. One hypothesis is that, once released, they spread passively through the space between cells. Instead, recent research has shown that some morphogens travel through long, thin cellular extensions known as cytonemes. These structures directly connect the cells that produce a morphogen with the ones that receive the molecule. Yet, it is still unclear how cytonemes can help to form gradients. Du et al. aimed to resolve this question by following a morphogen called Branchless as it traveled through fruit fly embryos. Branchless is important for sculpting the embryonic airway tissue into a delicate network of branched tubes which supply oxygen to the cells of an adult fly. However, no one knew how cells communicate Branchless, whether or not Branchless formed a gradient, and if it did, how this gradient was created to set up the plan to form airway tubes. It was assumed that the molecule would diffuse passively to reach airway cells – but this is not what the experiments by Du et al. showed. To directly observe how Branchless moves among cells, insects were genetically engineered to produce Branchless molecules attached to a fluorescent ‘tag’. Microscopy experiments using these flies revealed that Branchless did not diffuse passively; instead, airway cells used cytonemes to ‘reach’ towards the cells that produced the molecule, collecting the signal directly from its source. The gradient was created because the airway cells near the cells that make Branchless had more cytonemes, and therefore received more of the molecule compared to the cells that were placed further away. Genetic analysis of the airway tissue showed that Branchless acts as a morphogen to switch on different genes in the receiving cells placed in different locations. The target genes activated by the gradient instruct the receiving cells on how many cytonemes need to be extended, which helps the gradient to maintain itself over time. Du et al. demonstrate for the first time how cytonemes can relay a signal to establish a gradient in a developing tissue. Dissecting how cells exchange information to create an organism could help to understand how this communication fails and leads to disorders.
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Affiliation(s)
- Lijuan Du
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, United States
| | - Alex Sohr
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, United States
| | - Ge Yan
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, United States
| | - Sougata Roy
- Department of Cell Biology and Molecular Genetics, University of Maryland, Maryland, United States
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12
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Wear HM, Eriksson A, Yao HHC, Watanabe KH. Cell-based computational model of early ovarian development in mice. Biol Reprod 2018; 97:365-377. [PMID: 29088396 DOI: 10.1093/biolre/iox089] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 08/09/2017] [Indexed: 11/13/2022] Open
Abstract
Despite its importance to reproduction, certain mechanisms of early ovarian development remain a mystery. To improve our understanding, we constructed the first cell-based computational model of ovarian development in mice that is divided into two phases: Phase I spans embryonic day 5.5 (E5.5) to E12.5; and Phase II spans E12.5 to postnatal day 2. We used the model to investigate four mechanisms: in Phase I, (i) whether primordial germ cells (PGCs) undergo mitosis during migration; and (ii) if the mechanism for secretion of KIT ligand from the hindgut resembles inductive cell-cell signaling or is secreted in a static manner; and in Phase II, (iii) that changes in cellular adhesion produce germ cell nest breakdown; and (iv) whether localization of primordial follicles in the cortex of the ovary is due to proliferation of granulosa cells. We found that the combination of the first three hypotheses produced results that aligned with experimental images and PGC abundance data. Results from the fourth hypothesis did not match experimental images, which suggests that more detailed processes are involved in follicle localization. Phase I and Phase II of the model reproduce experimentally observed cell counts and morphology well. A sensitivity analysis identified contact energies, mitotic rates, KIT chemotaxis strength, and diffusion rate in Phase I and oocyte death rate in Phase II as parameters with the greatest impact on model predictions. The results demonstrate that the computational model can be used to understand unknown mechanisms, generate new hypotheses, and serve as an educational tool.
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Affiliation(s)
- Hannah M Wear
- Institute of Environmental Health, Oregon Health & Science University, Portland, OR, USA
| | - Annika Eriksson
- Division of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University Portland, OR, USA
| | - Humphrey Hung-Chang Yao
- Reproductive Developmental Biology Group, National Institute of Environmental Health Sciences, Research Triangle Park, NC, USA
| | - Karen H Watanabe
- Institute of Environmental Health, Oregon Health & Science University, Portland, OR, USA.,School of Public Health, Oregon Health & Science University, Portland, OR, USA
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13
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Stuelten CH, Parent CA, Montell DJ. Cell motility in cancer invasion and metastasis: insights from simple model organisms. Nat Rev Cancer 2018; 18:296-312. [PMID: 29546880 PMCID: PMC6790333 DOI: 10.1038/nrc.2018.15] [Citation(s) in RCA: 305] [Impact Index Per Article: 50.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Metastasis remains the greatest challenge in the clinical management of cancer. Cell motility is a fundamental and ancient cellular behaviour that contributes to metastasis and is conserved in simple organisms. In this Review, we evaluate insights relevant to human cancer that are derived from the study of cell motility in non-mammalian model organisms. Dictyostelium discoideum, Caenorhabditis elegans, Drosophila melanogaster and Danio rerio permit direct observation of cells moving in complex native environments and lend themselves to large-scale genetic and pharmacological screening. We highlight insights derived from each of these organisms, including the detailed signalling network that governs chemotaxis towards chemokines; a novel mechanism of basement membrane invasion; the positive role of E-cadherin in collective direction-sensing; the identification and optimization of kinase inhibitors for metastatic thyroid cancer on the basis of work in flies; and the value of zebrafish for live imaging, especially of vascular remodelling and interactions between tumour cells and host tissues. While the motility of tumour cells and certain host cells promotes metastatic spread, the motility of tumour-reactive T cells likely increases their antitumour effects. Therefore, it is important to elucidate the mechanisms underlying all types of cell motility, with the ultimate goal of identifying combination therapies that will increase the motility of beneficial cells and block the spread of harmful cells.
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Affiliation(s)
- Christina H. Stuelten
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA
| | - Carole A. Parent
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, NCI, NIH, Bethesda, MD, USA
- Department of Pharmacology, Michigan Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
- ;
| | - Denise J. Montell
- Molecular, Cellular, and Developmental Biology Department, University of California, Santa Barbara, CA, USA
- ;
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14
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Mekus Z, Cooley J, George A, Sabo V, Strzegowski M, Starz-Gaiano M, E. Peercy B. Effects of cell packing on chemoattractant distribution within a tissue. AIMS BIOPHYSICS 2018. [DOI: 10.3934/biophy.2018.1.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
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15
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Clark AG, Simon A, Aizel K, Bibette J, Bremond N, Vignjevic DM. 3D cell migration in the presence of chemical gradients using microfluidics. Methods Cell Biol 2018; 147:133-147. [DOI: 10.1016/bs.mcb.2018.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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16
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Deshpande G, Barr J, Gerlitz O, Lebedeva L, Shidlovskii Y, Schedl P. Cells on the move: Modulation of guidance cues during germ cell migration. Fly (Austin) 2017; 11:200-207. [PMID: 28300473 DOI: 10.1080/19336934.2017.1304332] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In Drosophila melanogaster the progenitors of the germ-line stem cells, the primordial germ cells (PGCs) are formed on the outside surface of the early embryo, while the somatic gonadal precursor cells (SGPs) are specified during mid-embryogenesis. To form the primitive embryonic gonad, the PGCs travel from outside of the embryo, across the mid-gut and then migrate through the mesoderm to the SGPs. The migratory path of PGCs is dictated by a series of attractive and repulsive cues. Studies in our laboratory have shown that one of the key chemoattractants is the Hedgehog (Hh) ligand. Although, Hh is expressed in other cell types, the long-distance transmission of this ligand is specifically potentiated in the SGPs by the hmgcr isoprenoid biosynthetic pathway. The distant transmission of the Hh ligand is gated by restricting expression of hmgcr to the SGPs. This is particularly relevant in light of the recent findings that an ABC transporter, mdr49 also acts in a mesoderm specific manner to release the germ cell attractant. Our studies have demonstrated that mdr49 functions in hh signaling likely via its role in the transport of cholesterol. Given the importance of cholesterol in the processing and long distance transmission of the Hh ligand, this observation has opened up an exciting avenue concerning the possible role of components of the sterol transport machinery in PGC migration.
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Affiliation(s)
- Girish Deshpande
- a Department of Molecular Biology , Princeton University , Princeton , NJ , USA
| | - Justinn Barr
- a Department of Molecular Biology , Princeton University , Princeton , NJ , USA
| | - Offer Gerlitz
- b Department of Developmental Biology and Cancer Research, IMRIC , The Hebrew University , Jerusalem , Israel
| | - Lyubov Lebedeva
- c Laboratory of Gene Expression Regulation in Development . Institute of Gene Biology , Moscow , Russia
| | - Yulii Shidlovskii
- c Laboratory of Gene Expression Regulation in Development . Institute of Gene Biology , Moscow , Russia
| | - Paul Schedl
- a Department of Molecular Biology , Princeton University , Princeton , NJ , USA.,c Laboratory of Gene Expression Regulation in Development . Institute of Gene Biology , Moscow , Russia
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17
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Ha VQ, Lykotrafitis G. IMPETUS - Interactive MultiPhysics Environment for Unified Simulations. J Biomech 2016; 49:4034-4038. [PMID: 27871677 DOI: 10.1016/j.jbiomech.2016.10.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 11/29/2022]
Abstract
We introduce IMPETUS - Interactive MultiPhysics Environment for Unified Simulations, an object oriented, easy-to-use, high performance, C++ program for three-dimensional simulations of complex physical systems that can benefit a large variety of research areas, especially in cell mechanics. The program implements cross-communication between locally interacting particles and continuum models residing in the same physical space while a network facilitates long-range particle interactions. Message Passing Interface is used for inter-processor communication for all simulations.
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Affiliation(s)
- Vi Q Ha
- Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA
| | - George Lykotrafitis
- Mechanical Engineering, University of Connecticut, Storrs, CT 06269, USA; Biomedical Engineering, University of Connecticut, Storrs, CT 06269, USA
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18
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Kilic O, Pamies D, Lavell E, Schiapparelli P, Feng Y, Hartung T, Bal-Price A, Hogberg HT, Quinones-Hinojosa A, Guerrero-Cazares H, Levchenko A. Brain-on-a-chip model enables analysis of human neuronal differentiation and chemotaxis. LAB ON A CHIP 2016; 16:4152-4162. [PMID: 27722368 DOI: 10.1039/c6lc00946h] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Migration of neural progenitors in the complex tissue environment of the central nervous system is not well understood. Progress in this area has the potential to drive breakthroughs in neuroregenerative therapies, brain cancer treatments, and neurodevelopmental studies. To a large extent, advances have been limited due to a lack of controlled environments recapitulating characteristics of the central nervous system milieu. Reductionist cell culture models are frequently too simplistic, and physiologically more relevant approaches such as ex vivo brain slices or in situ experiments provide little control and make information extraction difficult. Here, we present a brain-on-chip model that bridges the gap between cell culture and ex vivo/in vivo conditions through recapitulation of self-organized neural differentiation. We use a new multi-layer silicone elastomer device, over the course of four weeks to differentiate pluripotent human (NTERA2) cells into neuronal clusters interconnected with thick axonal bundles and interspersed with astrocytes, resembling the brain parenchyma. Neurons within the device express the neurofilament heavy (NF200) mature axonal marker and the microtubule-associated protein (MAP2ab) mature dendritic marker, demonstrating that the devices are sufficiently biocompatible to allow neuronal maturation. This neuronal-glial environment is interfaced with a layer of human brain microvascular endothelial cells showing characteristics of the blood-brain barrier including the expression of zonula occludens (ZO1) tight junctions and increased trans-endothelial electrical resistance. We used this device to model migration of human neural progenitors in response to chemotactic cues within a brain-tissue setting. We show that in the presence of an environment mimicking brain conditions, neural progenitor cells show a significantly enhanced chemotactic response towards shallow gradients of CXCL12, a key chemokine expressed during embryonic brain development and in pathological tissue regions of the central nervous system. Our brain-on-chip model thus provides a convenient and scalable model of neural differentiation and maturation extensible to analysis of complex cell and tissue behaviors.
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Affiliation(s)
- Onur Kilic
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - David Pamies
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
| | - Emily Lavell
- Department of Neurosurgery and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Paula Schiapparelli
- Department of Neurosurgery and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Yun Feng
- Department of Neurosurgery and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA. and Department of Pharmacology, School of Medical Science and Laboratory Medicine, Jiangsu University, Zhenjiang, People's Republic of China
| | - Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA and CAAT-Europe, University of Konstanz, Germany
| | - Anna Bal-Price
- European Commission, Joint Research Centre, Institute for Health and Consumer Protection, Ispra, Italy
| | - Helena T Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins University, Baltimore, MD, USA
| | - Alfredo Quinones-Hinojosa
- Department of Neurosurgery and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Hugo Guerrero-Cazares
- Department of Neurosurgery and Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Andre Levchenko
- Department of Biomedical Engineering and Yale Systems Biology Institute, Yale University, New Haven, CT, USA.
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19
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Chemotaxis during neural crest migration. Semin Cell Dev Biol 2016; 55:111-8. [DOI: 10.1016/j.semcdb.2016.01.031] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 01/22/2016] [Indexed: 01/12/2023]
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20
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Spill F, Andasari V, Mak M, Kamm RD, Zaman MH. Effects of 3D geometries on cellular gradient sensing and polarization. Phys Biol 2016; 13:036008. [PMID: 27345945 DOI: 10.1088/1478-3975/13/3/036008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
During cell migration, cells become polarized, change their shape, and move in response to various internal and external cues. Cell polarization is defined through the spatio-temporal organization of molecules such as PI3K or small GTPases, and is determined by intracellular signaling networks. It results in directional forces through actin polymerization and myosin contractions. Many existing mathematical models of cell polarization are formulated in terms of reaction-diffusion systems of interacting molecules, and are often defined in one or two spatial dimensions. In this paper, we introduce a 3D reaction-diffusion model of interacting molecules in a single cell, and find that cell geometry has an important role affecting the capability of a cell to polarize, or change polarization when an external signal changes direction. Our results suggest a geometrical argument why more roundish cells can repolarize more effectively than cells which are elongated along the direction of the original stimulus, and thus enable roundish cells to turn faster, as has been observed in experiments. On the other hand, elongated cells preferentially polarize along their main axis even when a gradient stimulus appears from another direction. Furthermore, our 3D model can accurately capture the effect of binding and unbinding of important regulators of cell polarization to and from the cell membrane. This spatial separation of membrane and cytosol, not possible to capture in 1D or 2D models, leads to marked differences of our model from comparable lower-dimensional models.
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Affiliation(s)
- Fabian Spill
- Department of Biomedical Engineering, Boston University, 44 Cummington Street, Boston MA 02215, USA. Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
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21
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Modeling and analysis of collective cell migration in an in vivo three-dimensional environment. Proc Natl Acad Sci U S A 2016; 113:E2134-41. [PMID: 27035964 DOI: 10.1073/pnas.1522656113] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A long-standing question in collective cell migration has been what might be the relative advantage of forming a cluster over migrating individually. Does an increase in the size of a collectively migrating group of cells enable them to sample the chemical gradient over a greater distance because the difference between front and rear of a cluster would be greater than for single cells? We combined theoretical modeling with experiments to study collective migration of the border cells in-between nurse cells in the Drosophila egg chamber. We discovered that cluster size is positively correlated with migration speed, up to a particular point above which speed plummets. This may be due to the effect of viscous drag from surrounding nurse cells together with confinement of all of the cells within a stiff extracellular matrix. The model predicts no relationship between cluster size and velocity for cells moving on a flat surface, in contrast to movement within a 3D environment. Our analyses also suggest that the overall chemoattractant profile in the egg chamber is likely to be exponential, with the highest concentration in the oocyte. These findings provide insights into collective chemotaxis by combining theoretical modeling with experimentation.
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22
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Mayor R, Etienne-Manneville S. The front and rear of collective cell migration. Nat Rev Mol Cell Biol 2016; 17:97-109. [PMID: 26726037 DOI: 10.1038/nrm.2015.14] [Citation(s) in RCA: 514] [Impact Index Per Article: 64.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Collective cell migration has a key role during morphogenesis and during wound healing and tissue renewal in the adult, and it is involved in cancer spreading. In addition to displaying a coordinated migratory behaviour, collectively migrating cells move more efficiently than if they migrated separately, which indicates that a cellular interplay occurs during collective cell migration. In recent years, evidence has accumulated confirming the importance of such intercellular communication and exploring the molecular mechanisms involved. These mechanisms are based both on direct physical interactions, which coordinate the cellular responses, and on the collective cell behaviour that generates an optimal environment for efficient directed migration. The recent studies have described how leader cells at the front of cell groups drive migration and have highlighted the importance of follower cells and cell-cell communication, both between followers and between follower and leader cells, to improve the efficiency of collective movement.
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Affiliation(s)
- Roberto Mayor
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Sandrine Etienne-Manneville
- Institut Pasteur, CNRS UMR 3691, Cell Polarity, Migration and Cancer Unit, 25 Rue du Dr Roux, 75724 Paris Cedex 15, France
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23
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Collective cell migration: guidance principles and hierarchies. Trends Cell Biol 2015; 25:556-66. [DOI: 10.1016/j.tcb.2015.06.003] [Citation(s) in RCA: 227] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/21/2015] [Accepted: 06/08/2015] [Indexed: 12/18/2022]
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24
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Szabó A, Mayor R. Cell traction in collective cell migration and morphogenesis: the chase and run mechanism. Cell Adh Migr 2015; 9:380-3. [PMID: 26267782 DOI: 10.1080/19336918.2015.1019997] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Directional collective cell migration plays an important role in development, physiology, and disease. An increasing number of studies revealed key aspects of how cells coordinate their movement through distances surpassing several cell diameters. While physical modeling and measurements of forces during collective cell movements helped to reveal key mechanisms, most of these studies focus on tightly connected epithelial cultures. Less is known about collective migration of mesenchymal cells. A typical example of such behavior is the migration of the neural crest cells, which migrate large distances as a group. A recent study revealed that this persistent migration is aided by the interaction between the neural crest and the neighboring placode cells, whereby neural crest chase the placodes via chemotaxis, but upon contact both populations undergo contact inhibition of locomotion and a rapid reorganization of cellular traction. The resulting asymmetric traction field of the placodes forces them to run away from the chasers. We argue that this chase and run interaction may not be specific only to the neural crest system, but could serve as the underlying mechanism for several morphogenetic processes involving collective cell migration.
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Affiliation(s)
- András Szabó
- a Department of Cell and Developmental Biology ; University College London ; London UK
| | - Roberto Mayor
- a Department of Cell and Developmental Biology ; University College London ; London UK
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25
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E-cadherin junctions as active mechanical integrators in tissue dynamics. Nat Cell Biol 2015; 17:533-9. [PMID: 25925582 DOI: 10.1038/ncb3136] [Citation(s) in RCA: 356] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
During epithelial morphogenesis, E-cadherin adhesive junctions play an important part in mechanically coupling the contractile cortices of cells together, thereby distributing the stresses that drive cell rearrangements at both local and tissue levels. Here we discuss the concept that cellular contractility and E-cadherin-based adhesion are functionally integrated by biomechanical feedback pathways that operate on molecular, cellular and tissue scales.
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