1
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Landais Y, Vallot C. Multi-modal quantification of pathway activity with MAYA. Nat Commun 2023; 14:1668. [PMID: 36966153 PMCID: PMC10039856 DOI: 10.1038/s41467-023-37410-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 03/16/2023] [Indexed: 03/27/2023] Open
Abstract
Signaling pathways can be activated through various cascades of genes depending on cell identity and biological context. Single-cell atlases now provide the opportunity to inspect such complexity in health and disease. Yet, existing reference tools for pathway scoring resume activity of each pathway to one unique common metric across cell types. Here, we present MAYA, a computational method that enables the automatic detection and scoring of the diverse modes of activation of biological pathways across cell populations. MAYA improves the granularity of pathway analysis by detecting subgroups of genes within reference pathways, each characteristic of a cell population and how it activates a pathway. Using multiple single-cell datasets, we demonstrate the biological relevance of identified modes of activation, the robustness of MAYA to noisy pathway lists and batch effect. MAYA can also predict cell types starting from lists of reference markers in a cluster-free manner. Finally, we show that MAYA reveals common modes of pathway activation in tumor cells across patients, opening the perspective to discover shared therapeutic vulnerabilities.
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Affiliation(s)
| | - Céline Vallot
- CNRS UMR3244, Institut Curie, PSL University, Paris, France.
- Translational Research Department, Institut Curie, PSL University, Paris, France.
- Single Cell Initiative, Institut Curie, PSL University, Paris, France.
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2
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Donta MS, Srivastava Y, McCrea PD. Delta-Catenin as a Modulator of Rho GTPases in Neurons. Front Cell Neurosci 2022; 16:939143. [PMID: 35860313 PMCID: PMC9289679 DOI: 10.3389/fncel.2022.939143] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 06/09/2022] [Indexed: 12/03/2022] Open
Abstract
Small Rho GTPases are molecular switches that are involved in multiple processes including regulation of the actin cytoskeleton. These GTPases are activated (turned on) and inactivated (turned off) through various upstream effector molecules to carry out many cellular functions. One such upstream modulator of small Rho GTPase activity is delta-catenin, which is a protein in the p120-catenin subfamily that is enriched in the central nervous system. Delta-catenin affects small GTPase activity to assist in the developmental formation of dendrites and dendritic spines and to maintain them once they mature. As the dendritic arbor and spine density are crucial for synapse formation and plasticity, delta-catenin’s ability to modulate small Rho GTPases is necessary for proper learning and memory. Accordingly, the misregulation of delta-catenin and small Rho GTPases has been implicated in several neurological and non-neurological pathologies. While links between delta-catenin and small Rho GTPases have yet to be studied in many contexts, known associations include some cancers, Alzheimer’s disease (AD), Cri-du-chat syndrome, and autism spectrum disorder (ASD). Drawing from established studies and recent discoveries, this review explores how delta-catenin modulates small Rho GTPase activity. Future studies will likely elucidate how PDZ proteins that bind delta-catenin further influence small Rho GTPases, how delta-catenin may affect small GTPase activity at adherens junctions when bound to N-cadherin, mechanisms behind delta-catenin’s ability to modulate Rac1 and Cdc42, and delta-catenin’s ability to modulate small Rho GTPases in the context of diseases, such as cancer and AD.
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Affiliation(s)
- Maxsam S. Donta
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
- Program in Genetics and Epigenetics, The University of Texas MD Anderson Cancer Center University of Texas Health Science Center Houston Graduate School of Biomedical Science, Houston, TX, United States
- *Correspondence: Maxsam S. Donta,
| | - Yogesh Srivastava
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Pierre D. McCrea
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
- Program in Genetics and Epigenetics, The University of Texas MD Anderson Cancer Center University of Texas Health Science Center Houston Graduate School of Biomedical Science, Houston, TX, United States
- Program in Neuroscience, The University of Texas MD Anderson Cancer Center University of Texas Health Science Center Houston Graduate School of Biomedical Science, Houston, TX, United States
- Pierre D. McCrea,
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3
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Kamasaki T, Miyazaki Y, Ishikawa S, Hoshiba K, Kuromiya K, Tanimura N, Mori Y, Tsutsumi M, Nemoto T, Uehara R, Suetsugu S, Itoh T, Fujita Y. FBP17-mediated finger-like membrane protrusions in cell competition between normal and RasV12-transformed cells. iScience 2021; 24:102994. [PMID: 34485872 PMCID: PMC8405961 DOI: 10.1016/j.isci.2021.102994] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/02/2021] [Accepted: 08/13/2021] [Indexed: 01/23/2023] Open
Abstract
At the initial stage of carcinogenesis, cell competition often occurs between newly emerging transformed cells and the neighboring normal cells, leading to the elimination of transformed cells from the epithelial layer. For instance, when RasV12-transformed cells are surrounded by normal cells, RasV12 cells are apically extruded from the epithelium. However, the underlying mechanisms of this tumor-suppressive process still remain enigmatic. We first show by electron microscopic analysis that characteristic finger-like membrane protrusions are projected from both normal and RasV12 cells at their interface. In addition, FBP17, a member of the F-BAR proteins, accumulates in RasV12 cells, as well as surrounding normal cells, which plays a positive role in the formation of finger-like protrusions and apical elimination of RasV12 cells. Furthermore, cdc42 acts upstream of these processes. These results suggest that the cdc42/FBP17 pathway is a crucial trigger of cell competition, inducing “protrusion to protrusion response” between normal and RasV12-transformed cells. EM analysis shows finger-like membrane protrusions between normal and RasV12 cells Cdc42/FBP17 regulate the formation of the finger-like membrane protrusions Cdc42/FBP17-mediated finger-like protrusions promote elimination of RasV12 cells ‘Protrusion to protrusion response’ triggers cell competition
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Affiliation(s)
- Tomoko Kamasaki
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan.,Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
| | - Yumi Miyazaki
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan
| | - Susumu Ishikawa
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan
| | - Kazuya Hoshiba
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan
| | - Keisuke Kuromiya
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan.,Department of Molecular Oncology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Nobuyuki Tanimura
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan.,Department of Molecular Oncology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Yusuke Mori
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan.,Department of Molecular Oncology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Motosuke Tsutsumi
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS) & National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Tomomi Nemoto
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan.,Exploratory Research Center on Life and Living Systems (ExCELLS) & National Institute for Physiological Sciences, National Institutes of Natural Sciences, Okazaki, Aichi 444-8787, Japan
| | - Ryota Uehara
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
| | - Shiro Suetsugu
- Division of Biological Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Toshiki Itoh
- Division of Membrane Biology, Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, Kobe, Hyogo 650-0017, Japan.,Biosignal Research Center, Kobe University, Kobe, Hyogo 657-8501, Japan
| | - Yasuyuki Fujita
- Division of Molecular Oncology, Institute for Genetic Medicine, Hokkaido University Graduate School of Chemical Sciences and Engineering, Sapporo, Hokkaido 060-0815, Japan.,Department of Molecular Oncology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
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4
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Argentati C, Morena F, Tortorella I, Bazzucchi M, Porcellati S, Emiliani C, Martino S. Insight into Mechanobiology: How Stem Cells Feel Mechanical Forces and Orchestrate Biological Functions. Int J Mol Sci 2019; 20:E5337. [PMID: 31717803 PMCID: PMC6862138 DOI: 10.3390/ijms20215337] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 10/23/2019] [Accepted: 10/25/2019] [Indexed: 12/12/2022] Open
Abstract
The cross-talk between stem cells and their microenvironment has been shown to have a direct impact on stem cells' decisions about proliferation, growth, migration, and differentiation. It is well known that stem cells, tissues, organs, and whole organisms change their internal architecture and composition in response to external physical stimuli, thanks to cells' ability to sense mechanical signals and elicit selected biological functions. Likewise, stem cells play an active role in governing the composition and the architecture of their microenvironment. Is now being documented that, thanks to this dynamic relationship, stemness identity and stem cell functions are maintained. In this work, we review the current knowledge in mechanobiology on stem cells. We start with the description of theoretical basis of mechanobiology, continue with the effects of mechanical cues on stem cells, development, pathology, and regenerative medicine, and emphasize the contribution in the field of the development of ex-vivo mechanobiology modelling and computational tools, which allow for evaluating the role of forces on stem cell biology.
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Affiliation(s)
- Chiara Argentati
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Francesco Morena
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Ilaria Tortorella
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Martina Bazzucchi
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Serena Porcellati
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
| | - Carla Emiliani
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
- CEMIN, Center of Excellence on Nanostructured Innovative Materials, Via del Giochetto, 06126 Perugia, Italy
| | - Sabata Martino
- Department of Chemistry, Biology and Biotechnologies, University of Perugia, Via del Giochetto, 06126 Perugia, Italy; (C.A.); (F.M.); (I.T.); (M.B.); (S.P.); (C.E.)
- CEMIN, Center of Excellence on Nanostructured Innovative Materials, Via del Giochetto, 06126 Perugia, Italy
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5
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Ankyrin-G regulated epithelial phenotype is required for mouse lens morphogenesis and growth. Dev Biol 2018; 446:119-131. [PMID: 30562487 DOI: 10.1016/j.ydbio.2018.12.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 12/13/2018] [Accepted: 12/14/2018] [Indexed: 11/24/2022]
Abstract
Epithelial cell polarity, adhesion, proliferation, differentiation and survival are essential for morphogenesis of various organs and tissues including the ocular lens. The molecular mechanisms regulating the lens epithelial phenotype however, are not well understood. Here we investigated the role of scaffolding protein ankyrin-G (AnkG) in mouse lens development by conditional suppression of AnkG expression using the Cre-LoxP recombination approach. AnkG, which serves to link integral membrane proteins to the spectrin/actin cytoskeleton, was found to distribute predominantly to the lateral membranes of lens epithelium with several isoforms of the protein being detected in the mouse lens. Conditional deficiency of AnkG impaired mouse lens morphogenesis starting from embryonic stage E15.5, with neonatal (P1) AnkG cKO lenses exhibiting overt abnormalities in shape, size, epithelial cell height, sheet length and lateral membrane assembly together with defective fiber cell orientation relative to lenses from littermate AnkG floxed or Cre expressing mice. Severe disruptions in E-cadherin/β-catenin-based adherens junctions, and the membrane organization of spectrin-actin cytoskeleton, ZO-1, connexin-50 and Na+-K+-ATPase were noted in AnkG deficient lenses, along with detection in lens epithelium of α-smooth muscle actin, a marker of epithelial to mesenchymal transition. Moreover, lens epithelial cell proliferation and survival were severely compromised while differentiation appears to be normal in AnkG deficient mouse lenses. Collectively, these results indicate that AnkG regulates establishment of the epithelial phenotype via lateral membrane assembly, stabilization of E-cadherin-based cell-cell junctions, polarity and membrane organization of transport and adhesion proteins and the spectrin-actin skeleton, and provide evidence for an obligatory role for AnkG in lens morphogenesis and growth.
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Hildebrand S, Hultin S, Subramani A, Petropoulos S, Zhang Y, Cao X, Mpindi J, Kalloniemi O, Johansson S, Majumdar A, Lanner F, Holmgren L. The E-cadherin/AmotL2 complex organizes actin filaments required for epithelial hexagonal packing and blastocyst hatching. Sci Rep 2017; 7:9540. [PMID: 28842668 PMCID: PMC5572699 DOI: 10.1038/s41598-017-10102-w] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 08/03/2017] [Indexed: 12/13/2022] Open
Abstract
Epithelial cells connect via cell-cell junctions to form sheets of cells with separate cellular compartments. These cellular connections are essential for the generation of cellular forms and shapes consistent with organ function. Tissue modulation is dependent on the fine-tuning of mechanical forces that are transmitted in part through the actin connection to E-cadherin as well as other components in the adherens junctions. In this report we show that p100 amotL2 forms a complex with E-cadherin that associates with radial actin filaments connecting cells over multiple layers. Genetic inactivation or depletion of amotL2 in epithelial cells in vitro or zebrafish and mouse in vivo, resulted in the loss of contractile actin filaments and perturbed epithelial packing geometry. We further showed that AMOTL2 mRNA and protein was expressed in the trophectoderm of human and mouse blastocysts. Genetic inactivation of amotL2 did not affect cellular differentiation but blocked hatching of the blastocysts from the zona pellucida. These results were mimicked by treatment with the myosin II inhibitor blebbistatin. We propose that the tension generated by the E-cadherin/AmotL2/actin filaments plays a crucial role in developmental processes such as epithelial geometrical packing as well as generation of forces required for blastocyst hatching.
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Affiliation(s)
- Sebastian Hildebrand
- Department of Clinical Sciences, Intervention and Technology (CLINTEC), Karolinska Institutet and Division of Obstetrics and Gynecology, Karolinska University Hospital, Huddinge, Sweden.,Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm, Sweden
| | - Sara Hultin
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm, Sweden
| | - Aravindh Subramani
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm, Sweden
| | - Sophie Petropoulos
- Department of Clinical Sciences, Intervention and Technology (CLINTEC), Karolinska Institutet and Division of Obstetrics and Gynecology, Karolinska University Hospital, Huddinge, Sweden
| | - Yuanyuan Zhang
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm, Sweden
| | - Xiaofang Cao
- Department of Medical Biochemistry and Microbiology, Uppsala Biomedical Center (BMC), Uppsala University, Uppsala, Sweden
| | - John Mpindi
- Medical Biotechnology, VTT Technical Research Centre of Finland, Turku, Finland.,Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Olli Kalloniemi
- Medical Biotechnology, VTT Technical Research Centre of Finland, Turku, Finland.,Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Helsinki, Finland
| | - Staffan Johansson
- Department of Medical Biochemistry and Microbiology, Uppsala Biomedical Center (BMC), Uppsala University, Uppsala, Sweden
| | - Arindam Majumdar
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm, Sweden.,Eli Lilly and Company, Lilly Corporate Center, Indianapolis, IN, 46285, USA
| | - Fredrik Lanner
- Department of Clinical Sciences, Intervention and Technology (CLINTEC), Karolinska Institutet and Division of Obstetrics and Gynecology, Karolinska University Hospital, Huddinge, Sweden.
| | - Lars Holmgren
- Department of Oncology-Pathology, Cancer Centrum Karolinska (CCK), Karolinska Institutet, Stockholm, Sweden.
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7
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Duzyj CM, Buhimschi IA, Motawea H, Laky CA, Cozzini G, Zhao G, Funai EF, Buhimschi CS. The invasive phenotype of placenta accreta extravillous trophoblasts associates with loss of E-cadherin. Placenta 2015; 36:645-51. [PMID: 25904157 DOI: 10.1016/j.placenta.2015.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/26/2015] [Accepted: 04/04/2015] [Indexed: 01/16/2023]
Abstract
INTRODUCTION Epithelial-to-mesenchymal transition (EMT) is a process of molecular and phenotypic epithelial cell alteration promoting invasiveness. Loss of E-cadherin (E-CAD), a transmembrane protein involved in cell adhesion, is a marker of EMT. Proteolysis into N- and C-terminus fragments by ADAM10 and presenilin-1 (PSEN-1) generates soluble (sE-CAD) and transcriptionally active forms. We studied the protein expression patterns of E-CAD in the serum and placenta of women with histologically-confirmed over-invasive placentation. METHODS The patterns of expression and levels of sE-CAD were analyzed by Western blot, immunoassay, and immunoprecipitation. Tissue immunostaining for E-CAD, cytokeratin-7 (epithelial marker), vimentin (mesenchymal marker), ADAM10, PSEN-1 and β-catenin expression were investigated in parallel. RESULTS N-terminus cleaved 80 kDa sE-CAD fragments were present in serum of pregnant women with gestational age regulation of the circulatory levels. Women with advanced trophoblast invasion did not display circulatory levels of sE-CAD different from those of women with normal placentation. Histologically, extravillous trophoblasts (EVT) closer to the placental-myometrial interface demonstrated less E-CAD staining than those found deeper in the myometrium. These cells expressed both vimentin and cytokeratin, an additional feature of EMT. EVT of placentas with advanced invasion displayed intracellular E-CAD C-terminus immunoreactivity predominating over that of the extracellular N-terminus, a pattern consistent with preferential PSEN-1 processing. DISCUSSION Local processing of E-CAD may be an important molecular mechanism controlling the invasive phenotype of accreta EVT.
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Affiliation(s)
- C M Duzyj
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA.
| | - I A Buhimschi
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA; Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43215, USA
| | - H Motawea
- Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43215, USA
| | - C A Laky
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - G Cozzini
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - G Zhao
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA; Center for Perinatal Research, The Research Institute at Nationwide Children's Hospital and Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH 43215, USA
| | - E F Funai
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
| | - C S Buhimschi
- Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, CT 06520, USA
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9
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Bhatt T, Rizvi A, Batta SPR, Kataria S, Jamora C. Signaling and mechanical roles of E-cadherin. ACTA ACUST UNITED AC 2013; 20:189-99. [PMID: 24205986 DOI: 10.3109/15419061.2013.854778] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The epithelium comprises an important tissue that lines the internal and external surfaces of metazoan organs. In order to organize sheets of epithelial cells into three-dimensional tissues, it requires the coordination of basic cellular processes such as polarity, adhesion, growth, and differentiation. Moreover, as a primary barrier to the external environment, epithelial tissues are often subjected to physical forces and damage. This critical barrier function dictates that these fundamental cellular processes are continually operational in order to maintain tissue homeostasis in the face of almost constant trauma and stress. A protein that is largely responsible for the organization and maintenance of epithelial tissues is the transmembrane protein, E-cadherin, found at the surface of epithelial cells. Though originally investigated for its essential role in mediating intercellular cohesion, its impact on a wide array of physiological processes underscores its fundamental contributions to tissue development and its perturbation in a variety of common diseases.
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Affiliation(s)
- Tanay Bhatt
- IFOM-inStem Joint Research Laboratory, Institute for Stem Cell Biology and Regenerative Medicine , Bangalore , India
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10
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ERK and RSK regulate distinct steps of a cellular program that induces transition from multicellular epithelium to single cell phenotype. Cell Signal 2013; 25:2743-51. [PMID: 24012955 DOI: 10.1016/j.cellsig.2013.08.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/23/2013] [Indexed: 01/13/2023]
Abstract
The ERK (extracellular signal-regulated kinases) cascade has an evolutionarily conserved three tier architecture consisting of protein kinases Raf, MEK (MAPK/ERK kinase) and ERK. Following activation, ERK phosphorylates various cellular elements leading to diverse cellular responses. Downstream of ERK the family of p90 ribosomal S6 kinases (RSKs) has been proven to be an important conveyor of ERK signaling, however, little is known if ERK and RSK coordinate their functions to generate a specific biological response. Here we show that in epithelial cells conditional activation of the ERK pathway causes phenotypic conversion of epithelial cells to autonomously migrating cells. This process involves two sequential steps characterized by loss of apical-basal polarity followed by cell scattering. The activation of ERK, but not RSK, is sufficient for the execution of the first step and it requires calpain mediated remodeling of actin cytoskeleton. Conversely, RSK regulates the successive stage characterized by cell-cell contact weakening and increased cellular migration. Thus, ERK and RSK regulate different cellular subprograms and coordinated execution of these subprograms in time generates a relevant biological response. Our data also suggest that the mechanism by which the ERK pathway controls a cellular response may be distributed between ERK and RSK, rather than being elicited by a single effector kinase.
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11
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Priya R, Yap AS, Gomez GA. E-cadherin supports steady-state Rho signaling at the epithelial zonula adherens. Differentiation 2013; 86:133-40. [PMID: 23643492 DOI: 10.1016/j.diff.2013.01.002] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Revised: 01/14/2013] [Accepted: 01/15/2013] [Indexed: 11/15/2022]
Abstract
In simple polarized epithelial cells, the Rho GTPase commonly localizes to E-cadherin-based cell-cell junctions, such as the zonula adherens (ZA), where it regulates the actomyosin cytoskeleton to support junctional integrity and tension. An important question is how E-cadherin contributes to Rho signaling, notably whether junctional Rho may depend on cadherin adhesion. We sought to investigate this by assessing Rho localization and activity in epithelial monolayers depleted of E-cadherin by RNAi. We report that E-cadherin depletion reduced both Rho and Rho-GTP at the ZA, an effect that was rescued by expressing a RNAi-resistant full-length E-cadherin transgene. This impact on Rho signaling was accompanied by reduced junctional localization of the Rho GEF ECT2 and the centralspindlin complex that recruits ECT2. Further, the Rho signaling pathway contributes to the selective stabilization of E-cadherin molecules in the apical zone of the cells compared with E-cadherin at the lateral surface, thereby creating a more defined and restricted pool of E-cadherin that forms the ZA. Thus, E-cadherin and Rho signaling cooperate to ensure proper ZA architecture and function.
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Affiliation(s)
- Rashmi Priya
- Division of Molecular Cell Biology, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Brisbane, Queensland 4072, Australia
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12
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Choi HJ, Kim J, Do KH, Park SH, Moon Y. Enteropathogenic Escherichia coli-induced macrophage inhibitory cytokine 1 mediates cancer cell survival: an in vitro implication of infection-linked tumor dissemination. Oncogene 2013; 32:4960-9. [PMID: 23503457 DOI: 10.1038/onc.2012.508] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 08/16/2012] [Accepted: 09/18/2012] [Indexed: 01/22/2023]
Abstract
Mucosally adherent Escherichia coli is frequently observed in intestinal surface of patients with colorectal cancer, but rarely in healthy control. Particularly, enteropathogenic Escherichia coli (EPEC) is known to be closely associated with colorectal carcinogenesis in human. In this study, one consequence of EPEC infection in human intestinal cancer cells was induction of macrophage inhibitory cytokine 1 (MIC-1), which is a multifunctional cytokine with biological activities involved in cancer cell growth, differentiation and migration. The present investigation assessed the involvement of MIC-1 protein in EPEC infection-mediated cancer cell survival. The challenge with EPEC induced cancer cell detachment via cytoskeleton rearrangement, which was positively associated with induced MIC-1 expression. Moreover, MIC-1 also mediated RhoA GTPase-linked survival of the detached cancer cells. Blocking of MIC-1 or RhoA activity increased cellular apoptosis of the detached cancer cells. In terms of signaling pathway, MIC-1 triggered transforming growth factorβ-activated kinase 1 (TAK1), which enhanced expression of RhoA GTPase. We conclude that EPEC enhances MIC-1 gene expression in the human intestinal cancer cells, which can be associated with enhanced tumor cell resistance to anchorage-dependent tumor cell death via enhanced TAK1 and RhoA GTPase.
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Affiliation(s)
- H J Choi
- Laboratory of Mucosal Exposome and Biomodulation, Department of Microbiology and Immunology and Medical Research Institute, Pusan National University School of Medicine, Yangsan, Kyungnam, Korea
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Abstract
In order to metastasize, cancer cells must first detach from the primary tumor, migrate, invade through tissues, and attach to a second site. Hakai was discovered as an E3 ubiquitin-ligase that mediates the posttranslational downregulation of E-cadherin, a major component of adherens junctions in epithelial cells that is characterized as a potent tumor suppressor and is modulated during various processes including epithelial–mesenchymal transition. Recent data have provided evidences for novel biological functional role of Hakai during tumor progression and other diseases. Here, we will review the knowledge that has been accumulated since Hakai discovery 10 years ago and its implication in human cancer disease. We will highlight the different signaling pathways leading to the influence on Hakai and suggest its potential usefulness as therapeutic target for cancer.
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Regulation of adherens junctions by Rho GTPases and p120-catenin. Arch Biochem Biophys 2012; 524:48-55. [PMID: 22583808 DOI: 10.1016/j.abb.2012.04.019] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 04/10/2012] [Accepted: 04/23/2012] [Indexed: 01/05/2023]
Abstract
The molecular mechanisms leading to tumor progression and acquisition of a metastatic phenotype are highly complex and only partially understood. The spatiotemporal regulation of E-cadherin-mediated adherens junctions is essential for normal epithelia function and tissue integrity. Perturbation of the E-cadherin complex assembly is a key event in epithelial-mesenchymal transition and is directed by a huge number of mechanisms that differ greatly with regard to cell types and tissues. The reduction in intercellular adhesion interferes with tissue integrity and allows cancer cells to disseminate from the primary tumor thereby initiating cancer metastasis. In the present review we will summarize the current findings about the influence of Rho GTPases on the formation and maintenance of adherens junction and will then proceed to discuss the involvement of p120-catenin on cell-cell adhesion and tumor cell migration.
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15
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McMullan R, Anderson A, Nurrish S. Behavioral and immune responses to infection require Gαq- RhoA signaling in C. elegans. PLoS Pathog 2012; 8:e1002530. [PMID: 22359503 PMCID: PMC3280986 DOI: 10.1371/journal.ppat.1002530] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 12/28/2011] [Indexed: 11/18/2022] Open
Abstract
Following pathogen infection the hosts' nervous and immune systems react with coordinated responses to the danger. A key question is how the neuronal and immune responses to pathogens are coordinated, are there common signaling pathways used by both responses? Using C. elegans we show that infection by pathogenic strains of M. nematophilum, but not exposure to avirulent strains, triggers behavioral and immune responses both of which require a conserved Gαq-RhoGEF Trio-Rho signaling pathway. Upon infection signaling by the Gαq pathway within cholinergic motorneurons is necessary and sufficient to increase release of the neurotransmitter acetylcholine and increase locomotion rates and these behavioral changes result in C. elegans leaving lawns of M. nematophilum. In the immune response to infection signaling by the Gαq pathway within rectal epithelial cells is necessary and sufficient to cause changes in cell morphology resulting in tail swelling that limits the infection. These Gαq mediated behavioral and immune responses to infection are separate, act in a cell autonomous fashion and activation of this pathway in the appropriate cells can trigger these responses in the absence of infection. Within the rectal epithelium the Gαq signaling pathway cooperates with a Ras signaling pathway to activate a Raf-ERK-MAPK pathway to trigger the cell morphology changes, whereas in motorneurons Gαq signaling triggers behavioral responses independent of Ras signaling. Thus, a conserved Gαq pathway cooperates with cell specific factors in the nervous and immune systems to produce appropriate responses to pathogen. Thus, our data suggests that ligands for Gq coupled receptors are likely to be part of the signals generated in response to M. nematophilum infection. Once infected by a pathogen the nervous and immune systems of many animals react with coordinated responses to the danger. A key question is what are the pathways by which responses to infection occur and to what extent are the same pathways involved in differing responses? Here we demonstrate that a Gαq-RhoA pathway is required for both behavioral and immune responses to infection in C. elegans. We show that Gαq-RhoA signaling is a late step in the response to infection and their site of action defines the cellular targets of signals generated internally in response to infection. One response is to move away from sites of pathogenic bacteria and Gαq-RhoA signaling acts in motorneurons to achieve this. A second response is an innate immune response where Gαq-RhoA signaling acts within cells close to sites of infection, the rectal epithelial cells, to cause major changes in their size and shape to mitigate the effects of infection. Our work demonstrates that ligands for Gq coupled GPCRs are likely to be required for response to infection. Identifying these ligands and the cells that release them will help define the mechanisms by which C. elegans recognizes pathogens and coordinates behavioral and immune responses to infection.
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Affiliation(s)
- Rachel McMullan
- MRC Cell Biology Unit, MRC Laboratory for Molecular Cell Biology and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London, United Kingdom
- * E-mail: (RM); (SN)
| | - Alexandra Anderson
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Stephen Nurrish
- MRC Cell Biology Unit, MRC Laboratory for Molecular Cell Biology and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- * E-mail: (RM); (SN)
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16
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Singh A, Winterbottom E, Daar IO. Eph/ephrin signaling in cell-cell and cell-substrate adhesion. Front Biosci (Landmark Ed) 2012; 17:473-97. [PMID: 22201756 DOI: 10.2741/3939] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cell-cell and cell-matrix adhesion are critical processes for the formation and maintenance of tissue patterns during development, as well as control of invasion and metastasis of cancer cells. Although great strides have been made regarding our understanding of the processes that play a role in cell adhesion and cell movement, the precise mechanisms by which diverse signaling events regulate cell and tissue architecture are poorly understood. One group of cell surface molecules, Eph receptor tyrosine kinases, and their membrane-bound ligands, ephrins, are key regulators in these processes. It is the ability of Eph/ephrin signaling pathways to regulate cell-cell adhesion and motility that establishes this family as a formidable system for regulating tissue separation and morphogenesis. Moreover, the de-regulation of this signaling system is linked to the promotion of more aggressive and metastatic tumors in humans.
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Affiliation(s)
- Arvinder Singh
- Laboratory of Cell and Developmental Signaling, National Cancer Institute-Frederick, Frederick, Maryland 21702, USA
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17
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Guillame-Gentil O, Semenov O, Roca AS, Groth T, Zahn R, Vörös J, Zenobi-Wong M. Engineering the extracellular environment: Strategies for building 2D and 3D cellular structures. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:5443-62. [PMID: 20842659 DOI: 10.1002/adma.201001747] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Indexed: 05/22/2023]
Abstract
Cell fate is regulated by extracellular environmental signals. Receptor specific interaction of the cell with proteins, glycans, soluble factors as well as neighboring cells can steer cells towards proliferation, differentiation, apoptosis or migration. In this review, approaches to build cellular structures by engineering aspects of the extracellular environment are described. These methods include non-specific modifications to control the wettability and stiffness of surfaces using self-assembled monolayers (SAMs) and polyelectrolyte multilayers (PEMs) as well as methods where the temporal activation and spatial distribution of adhesion ligands is controlled. Building on these techniques, construction of two-dimensional cell sheets using temperature sensitive polymers or electrochemical dissolution is described together with current applications of these grafts in the clinical arena. Finally, methods to pattern cells in three-dimensions as well as to functionalize the 3D environment with biologic motifs take us one step closer to being able to engineer multicellular tissues and organs.
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18
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Air–Liquid Interface Culture of Nasal Epithelial Cells on Denuded Amniotic Membranes. Cell Mol Bioeng 2010. [DOI: 10.1007/s12195-010-0118-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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19
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Suh HN, Han HJ. Laminin regulates mouse embryonic stem cell migration: involvement of Epac1/Rap1 and Rac1/cdc42. Am J Physiol Cell Physiol 2010; 298:C1159-69. [PMID: 20089929 DOI: 10.1152/ajpcell.00496.2009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Laminin is the first extracellular matrix (ECM) component to be expressed in the developing mammalian embryo. However, the roles of laminin or the related signal pathways are not well known in mouse embryonic stem cells (mESCs). Presently, we examined the effect of laminin on mESC migration. Laminin (10 microg/ml) decreased cell aggregation, whereas migration was increased. Laminin bound alpha6beta1 integrin and laminin receptor 1 (LR1), decreasing their mRNA levels. Laminin increased focal adhesion kinase (FAK) and paxillin phosphorylation, cAMP intracellular concentration, and the protein levels of exchange factor directly activated by cAMP (Epac1) and Rap1. These increases were completely blocked by alpha6beta1 integrin and LR1 neutralizing antibody, indicating that laminin-bound LR1 assists laminin-induced alpha6beta1 integrin activity and initiates signal. As a downstream signal molecule, laminin activated small G protein such as Rac1/cdc42 and its effector protein p21-activated kinase (PAK). Subsequently, laminin stimulated E-cadherin complex disruption. Inhibition of each pathway such as those for alpha6beta1 integrin and LR1, FAK, Rap1, and PAK1 blocked laminin-induced migration. We conclude that laminin binds both alpha6beta1 integrin and LR1 and induces signaling FAK/paxillin and cAMP/Epac1/Rap1. These signaling merge at Rac1/cdc42 subsequently activate PAK1. Activated PAK1 enhances E-cadherin complex disruption and finally increases mESCs migration.
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Affiliation(s)
- Han Na Suh
- Dept. of Veterinary Physiology, Chonnam National Univ., Gwangju, Korea
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20
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21
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Bradley WD, Koleske AJ. Regulation of cell migration and morphogenesis by Abl-family kinases: emerging mechanisms and physiological contexts. J Cell Sci 2009; 122:3441-54. [PMID: 19759284 DOI: 10.1242/jcs.039859] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The Abl-family non-receptor tyrosine kinases are essential regulators of the cytoskeleton. They transduce diverse extracellular cues into cytoskeletal rearrangements that have dramatic effects on cell motility and morphogenesis. Recent biochemical and genetic studies have revealed several mechanisms that Abl-family kinases use to mediate these effects. Abl-family kinases stimulate actin polymerization through the activation of cortactin, hematopoietic lineage cell-specific protein (HS1), WASp- and WAVE-family proteins, and Rac1. They also attenuate cell contractility by inhibiting RhoA and altering adhesion dynamics. These pathways impinge on several physiological processes, including development and maintenance of the nervous and immune systems, and epithelial morphogenesis. Elucidating how Abl-family kinases are regulated, and where and when they coordinate cytoskeletal changes, is essential for garnering a better understanding of these complex processes.
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Affiliation(s)
- William D Bradley
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA.
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22
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Kuznetsova LA, Bazou D, Edwards GO, Coakley WT. Multiple three-dimensional mammalian cell aggregates formed away from solid substrata in ultrasound standing waves. Biotechnol Prog 2009; 25:834-41. [PMID: 19399828 DOI: 10.1002/btpr.164] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Single and multiple three-dimensional cell aggregates of human red blood cells (RBCs) and HepG2 cells were formed rapidly in low mega-Hertz ultrasound standing wave fields of different geometries. A single discoid aggregate was formed in a half-wavelength pathlength resonator at a cell concentration sufficient to produce a 3D structure. Multiple cell aggregates were formed on the axis of a cylindrical resonator with a plane transducer (discoid aggregates); in a resonator with a tubular transducer and in the cross-fields of plane and tubular transducers and two plane orthogonal transducers (all cylindrical aggregates). Mechanically strong RBC aggregates were obtained by crosslinking with wheat germ agglutinin (WGA, a lectin). Scanning electron microscopy showed aggregate surface porous structures when RBCs were mixed with WGA before sonication and tighter packing when ultrasonically preformed aggregates were subsequently exposed to a flow containing WGA. HepG2 cell aggregates showed strong accumulation of F-actin at sites of cell-cell contact consistent with increased mechanical stability. The aggregates had a porous surface, and yet confocal microscopy revealed a tight packing of cells in the aggregate's inner core.
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23
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Hauge H, Fjelland KE, Sioud M, Aasheim HC. Evidence for the involvement of FAM110C protein in cell spreading and migration. Cell Signal 2009; 21:1866-73. [PMID: 19698782 DOI: 10.1016/j.cellsig.2009.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 08/03/2009] [Accepted: 08/07/2009] [Indexed: 10/20/2022]
Abstract
A number of factors, including protein kinases, Rho GTPases and actin and microtubule cytoskeletons play a crucial role in cell migration and spreading. We have recently shown that ectopic expression of FAM110C can alter cellular morphology by mechanisms yet to be determined. In this study, a FAM110C antiserum has been developed and used to study endogenously expressed FAM110C. Our data show that FAM110C is expressed by different cell lines and it can be detected throughout the cell. Interestingly, depletion of FAM110C by short interfering RNA reduced integrin-mediated filopodia formation, hepatocyte growth factor-induced migration, and phosphorylation of the Akt1 kinase in the epithelial cell line HepG2. Furthermore, co-immunoprecipitation and co-localization studies show that both ectopically and endogenously expressed FAM110C interact, or is part of a protein complex, with the Akt1 kinase. This interaction is transient and follows the activation of Akt1. In addition, we show that alpha-tubulin co-precipitates with FAM110C which further supports an interaction with the microtubule cytoskeleton. Collectively, these findings suggest a new function for FAM110C in the regulation of cell spreading, migration and filopodia induction.
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Affiliation(s)
- Helena Hauge
- Department of Immunology the Norwegian Radium Hospital Rikshospitalet University Hospital, Oslo, Norway
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24
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Meng W, Takeichi M. Adherens junction: molecular architecture and regulation. Cold Spring Harb Perspect Biol 2009; 1:a002899. [PMID: 20457565 DOI: 10.1101/cshperspect.a002899] [Citation(s) in RCA: 389] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The adherens junction (AJ) is an element of the cell-cell junction in which cadherin receptors bridge the neighboring plasma membranes via their homophilic interactions. Cadherins associate with cytoplasmic proteins, called catenins, which in turn bind to cytoskeletal components, such as actin filaments and microtubules. These molecular complexes further interact with other proteins, including signaling molecules, rendering the AJs into highly dynamic and regulatable structures. The AJs of such nature contribute to the physical linking of cells, as well as to the regulation of cell-cell contacts, which is essential for morphogenesis and remodeling of tissues and organs. Thus, elucidating the molecular architecture of the AJs and their regulatory mechanisms are crucial for understanding how the multicellular system is organized.
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Affiliation(s)
- Wenxiang Meng
- RIKEN Center for Developmental Biology, Chuo-ku, Kobe 650-0047, Japan
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25
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Bazou D, Blain EJ, Terence Coakley W, Bazou D, Blain EJ, Terence Coakley W. NCAM and PSA-NCAM dependent membrane spreading and F-actin reorganization in suspended adhering neural cells. Mol Membr Biol 2009; 25:102-14. [DOI: 10.1080/09687680701618365] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Despina Bazou
- School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Emma J. Blain
- School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | | | - Despina Bazou
- School of Biosciences, Cardiff University, Cardiff, Wales, UK
| | - Emma J. Blain
- School of Biosciences, Cardiff University, Cardiff, Wales, UK
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26
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Bazou D, Foster GA, Ralphs JR, Coakley WT. Molecular adhesion development in a neural cell monolayer forming in an ultrasound trap. Mol Membr Biol 2009; 22:229-40. [PMID: 16096265 DOI: 10.1080/09687860500093396] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A 2-dimensional aggregate of C6 neural cells was formed rapidly (within 30 s) in suspension in a recently developed 1.5 MHz ultrasound standing wave trap. A typical 1 mm diameter aggregate contained about 3,500 cells. Spreading of membrane occurred between the aggregated cells. The rate of spreading of the tangentially developing intercellular contact area was 0.19 microm/min. The form of the suspended aggregate changed from one of a hexagonal arrangement of cells to one of a cell-monolayer-like continuous sheet of mostly quadrilateral and pentagonal cells as in a cell monolayer on a solid substratum. A range of fluorescent indicators showed that the >99% viability of the cells did not change during 1 h exposures; therefore cell viability was not compromised during the monolayer development. The average integral intensities from stained actin filaments at the spreading cell-cell interfaces after 1, 8 and 30 min were 14, 25 and 46 microm(2) respectively. The cells in this work progressed from physical aggregation, through molecular adhesion, to displaying the intracellular consequences of receptor interactions. The ability to form mechanically strong confluent monolayer structures that can be monitored in situ or harvested from the trap provides a technique with general potential for monitoring the synchronous development of cell responses to receptor-triggered adhesion.
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Affiliation(s)
- Despina Bazou
- Cardiff School of Biosciences, Cardiff University, Cardiff CF10 3TL, Wales, UK
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27
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Deplazes J, Fuchs M, Rauser S, Genth H, Lengyel E, Busch R, Luber B. Rac1 and Rho contribute to the migratory and invasive phenotype associated with somatic E-cadherin mutation. Hum Mol Genet 2009; 18:3632-44. [PMID: 19584084 DOI: 10.1093/hmg/ddp312] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Recent evidence suggests a close association between extracellular E-cadherin mutation in diffuse-type gastric carcinoma and the acquisition of a migratory phenotype of tumour cells. To characterize the cellular machinery that mediates the gain of motility of tumour cells with mutant E-cadherin, we turned to the small Rho GTPases Rac1 and Rho because they have been implicated in pathological processes including tumour cell migration and invasion. In the present study, we analyse the activity of Rac1 and Rho in relation to E-cadherin harbouring an in-frame deletion of exon 8 and prove for the first time that the mutation reduces the ability of E-cadherin to activate Rac1 and to inhibit Rho. We provide evidence that the lack of Rac1 activation observed in response to mutant E-cadherin influences the downstream signalling of Rac1, as is shown by the decrease in the binding of the Rac1 effector protein IQGAP1 to Rac1-GTP. Moreover, reduced membranous localization of p120-catenin in mutant E-cadherin expressing cells provides an explanation for the lack of negative regulation of Rho by mutant E-cadherin. Further, we show by time-lapse laser scanning microscopy and invasion assay that the enhanced motility and invasion associated with mutant E-cadherin is sensitive to the inhibition of Rac1 and Rho. Together, these findings present evidence that the mutation of E-cadherin influences Rac1 and Rho activation in opposite directions and that Rac1 and Rho are involved in the establishment of the migratory and invasive phenotype of tumour cells that have an E-cadherin mutation.
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Affiliation(s)
- Joëlle Deplazes
- Institut für Allgemeine Pathologie und Pathologische Anatomie, Technische Universität München, Klinikum rechts der Isar, 81675 München, Germany
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28
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Popoff MR, Geny B. Multifaceted role of Rho, Rac, Cdc42 and Ras in intercellular junctions, lessons from toxins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2009; 1788:797-812. [PMID: 19366594 DOI: 10.1016/j.bbamem.2009.01.011] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 01/20/2009] [Accepted: 01/22/2009] [Indexed: 12/20/2022]
Abstract
Tight junctions (TJs) and adherens junctions (AJs) are dynamic structures linked to the actin cytoskeleton, which control the paracellular permeability of epithelial and endothelial barriers. TJs and AJs are strictly regulated in a spatio-temporal manner by a complex signaling network, including Rho/Ras-GTPases, which have a pivotal role. Rho preferentially regulates TJs by controlling the contraction of apical acto-myosin filaments, whereas Rac/Cdc42 mainly coordinate the assembly-disassembly of AJ components. However, a subtle balance of Rho/Ras-GTPase activity and interplay between these molecules is required to maintain an optimal organization and function of TJs and AJs. Conversely, integrity of intercellular junctions generates signals through Rho-GTPases, which are involved in the regulation of multiple cellular processes. Rho/Ras-GTPases and the control of intercellular junctions are the target of various bacterial toxins responsible for severe diseases in man and animals, and are part of their mechanism of action. This review focuses on the regulation of TJs and AJs by Rho/Ras-GTPases through molecular approaches and bacterial toxins.
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Affiliation(s)
- Michel R Popoff
- Institut Pasteur, Unité des Bactéries anaérobies et Toxines, 75724 Paris cedex151, France.
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29
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Asuri S, Yan J, Paranavitana NC, Quilliam LA. E-cadherin dis-engagement activates the Rap1 GTPase. J Cell Biochem 2009; 105:1027-37. [PMID: 18767072 DOI: 10.1002/jcb.21902] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
E-cadherin based adherens junctions are finely regulated by multiple cellular signaling events. Here we show that the Ras-related Rap1 GTPase is enriched in regions of nascent cell-cell contacts and strengthens E-cadherin junctions: constitutively active Rap1 expressing MDCK cells exhibit increased junctional contact and resisted calcium depletion-induced cell-cell junction disruption. E-cadherin disengagement activated Rap1 and this correlated with E-cadherin association with the Rap GEFs, C3G and PDZ-GEF I. PDZ-GEF I associated with E-cadherin and beta-catenin whereas C3G interaction with E-cadherin did not involve beta-catenin. Knockdown of PDZ-GEF I in MDCK cells decreased Rap1 activity following E-cadherin junction disruption. We hereby show that Rap1 plays a role in the maintenance and repair of E-cadherin junctions and is activated via an "outside-in" signaling pathway initiated by E-cadherin and mediated at least in part by PDZ-GEF I.
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Affiliation(s)
- Sirisha Asuri
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine and Walther Oncology Center, Indianapolis, Indiana 46202, USA
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30
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A negative modulatory role for rho and rho-associated kinase signaling in delamination of neural crest cells. Neural Dev 2008; 3:27. [PMID: 18945340 PMCID: PMC2577655 DOI: 10.1186/1749-8104-3-27] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 10/22/2008] [Indexed: 11/27/2022] Open
Abstract
Background Neural crest progenitors arise as epithelial cells and then undergo a process of epithelial to mesenchymal transition that precedes the generation of cellular motility and subsequent migration. We aim at understanding the underlying molecular network. Along this line, possible roles of Rho GTPases that act as molecular switches to control a variety of signal transduction pathways remain virtually unexplored, as are putative interactions between Rho proteins and additional known components of this cascade. Results We investigated the role of Rho/Rock signaling in neural crest delamination. Active RhoA and RhoB are expressed in the membrane of epithelial progenitors and are downregulated upon delamination. In vivo loss-of-function of RhoA or RhoB or of overall Rho signaling by C3 transferase enhanced and/or triggered premature crest delamination yet had no effect on cell specification. Consistently, treatment of explanted neural primordia with membrane-permeable C3 or with the Rock inhibitor Y27632 both accelerated and enhanced crest emigration without affecting cell proliferation. These treatments altered neural crest morphology by reducing stress fibers, focal adhesions and downregulating membrane-bound N-cadherin. Reciprocally, activation of endogenous Rho by lysophosphatidic acid inhibited emigration while enhancing the above. Since delamination is triggered by BMP and requires G1/S transition, we examined their relationship with Rho. Blocking Rho/Rock function rescued crest emigration upon treatment with noggin or with the G1/S inhibitor mimosine. In the latter condition, cells emigrated while arrested at G1. Conversely, BMP4 was unable to rescue cell emigration when endogenous Rho activity was enhanced by lysophosphatidic acid. Conclusion Rho-GTPases, through Rock, act downstream of BMP and of G1/S transition to negatively regulate crest delamination by modifying cytoskeleton assembly and intercellular adhesion.
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Klein EA, Campbell LE, Kothapalli D, Fournier AK, Assoian RK. Joint requirement for Rac and ERK activities underlies the mid-G1 phase induction of cyclin D1 and S phase entry in both epithelial and mesenchymal cells. J Biol Chem 2008; 283:30911-8. [PMID: 18715870 DOI: 10.1074/jbc.m804537200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cyclin D1 gene induction is a key event in G1 phase progression. Our previous studies indicated that signaling to cyclin D1 is cell type-dependent because the timing of cyclin D1 gene expression in MCF10A mammary epithelial cells and mesenchymal cells such as fibroblasts and vascular smooth muscle cells is very different, with epithelial cells first expressing cyclin D1 in early rather than mid-G1 phase. In this report, we induced a mesenchymal phenotype in MCF10A cells by long-term exposure to TGF-beta and used the control and transitioned cells to examine cell type specificity of the signaling pathways that regulate cyclin D1 gene expression. We show that early-G1 phase cyclin D1 gene expression in MCF10A cells is under the control of Rac, whereas mid-G1 phase cyclin D1 induction requires parallel signaling from Rac and ERK, both in the control and transitioned cells. This combined requirement for Rac and ERK signaling is associated with an increased requirement for intracellular tension, Rb phosphorylation, and S phase entry. A similar co-regulation of cyclin D1 mRNA by Rac and ERK is seen in primary mesenchymal cells. Overall, our results reveal two mechanistically distinct phases of Rac-dependent cyclin D1 expression and emphasize that the acquisition of Rac/ERK co-dependence is required for the mid-G1 phase induction of cyclin D1 associated with S phase entry.
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Affiliation(s)
- Eric A Klein
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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32
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Epithelial histogenesis during tooth development. Arch Oral Biol 2008; 54 Suppl 1:S25-33. [PMID: 18656852 DOI: 10.1016/j.archoralbio.2008.05.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2008] [Revised: 05/07/2008] [Accepted: 05/07/2008] [Indexed: 12/31/2022]
Abstract
This paper reviews the current understanding of the progressive changes mediating dental epithelial histogenesis as a basis for future collaborative studies. Tooth development involves morphogenesis, epithelial histogenesis and cell differentiation. The consecutive morphological stages of lamina, bud, cap and bell are also characterized by changes in epithelial histogenesis. Differential cell proliferation rates, apoptosis, and alterations in adhesion and shape lead to the positioning of groups of cells with different functions. During tooth histo-morphogenesis changes occur in basement membrane composition, expression of signalling molecules and the localization of cell surface components. Cell positional identity may be related to cell history. Another important parameter is cell plasticity. Independently of signalling molecules, which play a major role in inducing or modulating specific steps, cell-cell and cell-matrix interactions regulate the plasticity/rigidity of particular domains of the enamel organ. This involves specifying in space the differential growth and influences the progressive tooth morphogenesis by shaping the epithelial-mesenchymal junction. Deposition of a mineralized matrix determines the final shape of the crown. All data reviewed in this paper were investigated in the mouse.
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33
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Lozano E, Frasa MAM, Smolarczyk K, Knaus UG, Braga VMM. PAK is required for the disruption of E-cadherin adhesion by the small GTPase Rac. J Cell Sci 2008; 121:933-8. [DOI: 10.1242/jcs.016121] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
E-cadherin cell-cell adhesion plays a major role in the maintenance of the morphology and function of epithelial tissues. Modulation of E-cadherin function is an important process in morphogenesis and tumour de-differentiation. We have previously shown that constitutively active Rac1 induces the disassembly of E-cadherin complexes from junctions in human keratinocytes. Here, we compare this activity in three members of the Rac subfamily (Rac1, Rac3 and Rac1b) and investigate the molecular mechanisms underlying Rac1-induced destabilization of junctions. We demonstrate that Rac3 shares with Rac1 the ability to interfere with cadherin-mediated adhesion. Rac1b is an alternative splice variant of Rac1 but, surprisingly, Rac1b cannot induce junction disassembly. Thus, Rac family members differ on their potential to perturb keratinocyte cell-cell contacts. The mechanism through which Rac promotes disassembly of cadherin-dependent adhesion does not involve an increase in contractility. Instead, activation of the Rac target PAK1 is necessary for destabilization of cell-cell contacts. Inhibition of PAK1 by dominant-negative constructs or depletion of endogenous PAK1 by RNA interference efficiently blocked Rac1-induced perturbation of junctions. Interestingly, PAK1 cannot be activated by Rac1b, suggesting that this may contribute to the inability of Rac1b to disrupt cell-cell contacts in keratinocytes. As PAK1 also plays a crucial role in lamellipodia formation, our data indicate that PAK1 is at the interface between junction destabilization and increased motility during morphogenetic events.
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Affiliation(s)
- Encarnación Lozano
- Molecular Medicine Section, NHLI, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
- Ecology and Evolution Research Section, Faculty of Life Sciences, Imperial College London, London, SW7 2AZ, UK
| | - Marieke A. M. Frasa
- Molecular Medicine Section, NHLI, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Katarzyna Smolarczyk
- Molecular Medicine Section, NHLI, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Ulla G. Knaus
- Department of Immunology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Vania M. M. Braga
- Molecular Medicine Section, NHLI, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
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Yue PYK, Mak NK, Cheng YK, Leung KW, Ng TB, Fan DTP, Yeung HW, Wong RNS. Pharmacogenomics and the Yin/Yang actions of ginseng: anti-tumor, angiomodulating and steroid-like activities of ginsenosides. Chin Med 2007; 2:6. [PMID: 17502003 PMCID: PMC1876803 DOI: 10.1186/1749-8546-2-6] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Accepted: 05/15/2007] [Indexed: 12/17/2022] Open
Abstract
In Chinese medicine, ginseng (Panax ginseng C.A. Meyer) has long been used as a general tonic or an adaptogen to promote longevity and enhance bodily functions. It has also been claimed to be effective in combating stress, fatigue, oxidants, cancer and diabetes mellitus. Most of the pharmacological actions of ginseng are attributed to one type of its constituents, namely the ginsenosides. In this review, we focus on the recent advances in the study of ginsenosides on angiogenesis which is related to many pathological conditions including tumor progression and cardiovascular dysfunctions. Angiogenesis in the human body is regulated by two sets of counteracting factors, angiogenic stimulators and inhibitors. The 'Yin and Yang' action of ginseng on angiomodulation was paralleled by the experimental data showing angiogenesis was indeed related to the compositional ratio between ginsenosides Rg1 and Rb1. Rg1 was later found to stimulate angiogenesis through augmenting the production of nitric oxide (NO) and vascular endothelial growth factor (VEGF). Mechanistic studies revealed that such responses were mediated through the PI3K-->Akt pathway. By means of DNA microarray, a group of genes related to cell adhesion, migration and cytoskeleton were found to be up-regulated in endothelial cells. These gene products may interact in a hierarchical cascade pattern to modulate cell architectural dynamics which is concomitant to the observed phenomena in angiogenesis. By contrast, the anti-tumor and anti-angiogenic effects of ginsenosides (e.g. Rg3 and Rh2) have been demonstrated in various models of tumor and endothelial cells, indicating that ginsenosides with opposing activities are present in ginseng. Ginsenosides and Panax ginseng extracts have been shown to exert protective effects on vascular dysfunctions, such as hypertension, atherosclerotic disorders and ischemic injury. Recent work has demonstrates the target molecules of ginsenosides to be a group of nuclear steroid hormone receptors. These lines of evidence support that the interaction between ginsenosides and various nuclear steroid hormone receptors may explain the diverse pharmacological activities of ginseng. These findings may also lead to development of more efficacious ginseng-derived therapeutics for angiogenesis-related diseases.
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Affiliation(s)
- Patrick Ying Kit Yue
- Department of Biology, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Nai Ki Mak
- Department of Biology, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Yuen Kit Cheng
- Department of Chemistry, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Kar Wah Leung
- Department of Biology, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
| | - Tzi Bun Ng
- Department of Biochemistry, Faculty of Medicine, Chinese University of Hong Kong, Hong Kong SAR, China
| | - David Tai Ping Fan
- Angiogenesis & TCM Laboratory, Department of Pharmacology, University of Cambridge, Tennis Court Road, CB2 1PD, UK
| | - Hin Wing Yeung
- International Society for Chinese Medicine, A & C, 1floor, Block 2, University of Macau, Av. Padre Tomas Pereira, Taipa, Macao SAR, China
| | - Ricky Ngok Shun Wong
- Department of Biology, Faculty of Science, Hong Kong Baptist University, Kowloon Tong, Hong Kong SAR, China
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Bisson N, Poitras L, Mikryukov A, Tremblay M, Moss T. EphA4 signaling regulates blastomere adhesion in the Xenopus embryo by recruiting Pak1 to suppress Cdc42 function. Mol Biol Cell 2007; 18:1030-43. [PMID: 17215521 PMCID: PMC1805096 DOI: 10.1091/mbc.e06-04-0294] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Revised: 12/04/2006] [Accepted: 12/29/2006] [Indexed: 12/19/2022] Open
Abstract
The control of cell adhesion is an important mechanism by which Eph receptors regulate cell sorting during development. Activation of EphA4 in Xenopus blastulae induces a reversible, cell autonomous loss-of-adhesion and disruption of the blastocoel roof. We show this phenotype is rescued by Nckbeta (Grb4) dependent on its interaction with EphA4. Xenopus p21(Cdc42/Rac)-activated kinase xPAK1 interacts with Nck, is activated in embryo by EphA4 in an Nck-dependent manner, and is required for EphA4-induced loss-of-adhesion. Ectopic expression of xPAK1 phenocopies EphA4 activation. This does not require the catalytic activity of xPAK1, but it does require its GTPase binding domain and is enhanced by membrane targeting. Indeed, membrane targeting of the GTPase binding domain (GBD) of xPAK1 alone is sufficient to phenocopy EphA4 loss-of-adhesion. Both EphA4 and the xPAK1-GBD down-regulate RhoA-GTP levels, and consistent with this, loss-of-adhesion can be rescued by activated Cdc42, Rac, and RhoA and can be epistatically induced by dominant-negative RhoA. Despite this, neither Cdc42 nor Rac activities are down-regulated by EphA4 activation or by the xPAK1-GBD. Together, the data suggest that EphA4 activation sequesters active Cdc42 and in this way down-regulates cell-cell adhesion. This novel signaling pathway suggests a mechanism for EphA4-guided migration.
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Affiliation(s)
- Nicolas Bisson
- Cancer Research Centre and Department of Medical Biology, Laval University, Hôtel-Dieu de Québec, Québec, G1R 2J6 Québec, Canada
| | - Luc Poitras
- Cancer Research Centre and Department of Medical Biology, Laval University, Hôtel-Dieu de Québec, Québec, G1R 2J6 Québec, Canada
| | - Alexander Mikryukov
- Cancer Research Centre and Department of Medical Biology, Laval University, Hôtel-Dieu de Québec, Québec, G1R 2J6 Québec, Canada
| | - Michel Tremblay
- Cancer Research Centre and Department of Medical Biology, Laval University, Hôtel-Dieu de Québec, Québec, G1R 2J6 Québec, Canada
| | - Tom Moss
- Cancer Research Centre and Department of Medical Biology, Laval University, Hôtel-Dieu de Québec, Québec, G1R 2J6 Québec, Canada
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36
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Brusés JL. N-cadherin signaling in synapse formation and neuronal physiology. Mol Neurobiol 2007; 33:237-52. [PMID: 16954598 DOI: 10.1385/mn:33:3:237] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Revised: 11/30/1999] [Accepted: 02/22/2006] [Indexed: 11/11/2022]
Abstract
Neural cadherin (N-cadherin) is an adhesion receptor that is localized in abundance at neuronto- neuron synapses. N-cadherin contains an extracellular domain that binds to other cadherins on juxtaposed cell membranes, a single-pass transmembrane region, and a cytoplasmic tail that interacts with various proteins, including catenins, kinases, phosphatases, and presenilin 1. N-cadherin contributes to the structural and functional organization of the synaptic complex by ensuring the adhesion between synaptic membranes and organizing the underlying actin cytoskeleton. Additionally, recent findings have shown that N-cadherin may participate in synaptic physiology by regulating calcium influx through voltage-activated calcium currents. The diverse activities of N-cadherin stem from its ability to operate as both an adhesion molecule that links cytoskeletons across cell membranes and a ligand-activated homophilic receptor capable of initiating intracellular signaling. An important mechanism of cadherin signaling is the regulation of small Rho guanosine triphosphatase activity that affects cytoskeleton dynamics and calcium influx. Because both the regulation of cadherin adhesive activity and cadherin-mediated signaling are affected by the binding of molecules to the intracellular domain, changes in the composition of the N-cadherin complex are central to the regulation of cadherin-mediated functions. This article focuses on the roles that N-cadherin might play at the level of the synapse through its effect on adhesion and signaling in the proximity of the synaptic junction.
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Affiliation(s)
- Juan L Brusés
- Department of Anatomy and Cell Biology, Kansas University Medical Center, Kansas City, KS, USA.
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37
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Ohashi T, Sugaya Y, Sakamoto N, Sato M. Hydrostatic pressure influences morphology and expression of VE-cadherin of vascular endothelial cells. J Biomech 2007; 40:2399-405. [PMID: 17261311 DOI: 10.1016/j.jbiomech.2006.11.023] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Accepted: 11/28/2006] [Indexed: 11/30/2022]
Abstract
Bovine aortic endothelial cells (BAECs) were exposed to hydrostatic pressures of 50, 100, and 150 mmHg and changes in morphology and expression of vascular endothelial (VE)-cadherin were studied. After exposure to hydrostatic pressure, BAECs exhibited elongated and tortuous shape without predominant orientation, together with the development of centrally located, thick stress fibers. Pressured BAECs also exhibited a multilayered structure unlike those under control conditions and showed a significant increase in proliferation compared with control cells. Western blot analysis demonstrated that protein level of VE-cadherin were significantly lower under pressure conditions than under control conditions. Inhibition of VE-cadherin expression, using an antibody to VE-cadherin, induced the formation of numerous randomly distributed intercellular gaps, elongated and tortuous shapes, and multilayering. These responses were similar to those of pressured BAECs. The exposure of BAECs to hydrostatic pressure may therefore downregulate the expression of VE-cadherin, resulting in loss of contact inhibition followed by increased proliferation and formation of a multilayered structure.
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Affiliation(s)
- Toshiro Ohashi
- Department of Bioengineering and Robotics, Graduate School of Engineering, Tohoku University, 6-6-01 Aramaki-Aoba, Aoba, Sendai 980-8579, Japan.
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38
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Simões S, Denholm B, Azevedo D, Sotillos S, Martin P, Skaer H, Hombría JCG, Jacinto A. Compartmentalisation of Rho regulators directs cell invagination during tissue morphogenesis. Development 2006; 133:4257-67. [PMID: 17021037 DOI: 10.1242/dev.02588] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
During development, small RhoGTPases control the precise cell shape changes and movements that underlie morphogenesis. Their activity must be tightly regulated in time and space, but little is known about how Rho regulators(RhoGEFs and RhoGAPs) perform this function in the embryo. Taking advantage of a new probe that allows the visualisation of small RhoGTPase activity in Drosophila, we present evidence that Rho1 is apically activated and essential for epithelial cell invagination, a common morphogenetic movement during embryogenesis. In the posterior spiracles of the fly embryo, this asymmetric activation is achieved by at least two mechanisms: the apical enrichment of Rho1; and the opposing distribution of Rho activators and inhibitors to distinct compartments of the cell membrane. At least two Rho1 activators, RhoGEF2 and RhoGEF64C are localised apically, whereas the Rho inhibitor RhoGAP Cv-c localises at the basolateral membrane. Furthermore, the mRNA of RhoGEF64C is also apically enriched, depending on signals present within its open reading frame, suggesting that apical transport of RhoGEF mRNA followed by local translation is a mechanism to spatially restrict Rho1 activity during epithelial cell invagination.
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Affiliation(s)
- Sérgio Simões
- Instituto de Medicina Molecular, Faculdade de Medicina de Lisboa, Portugal
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39
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Abstract
E-cadherin has been linked to the suppression of tumor growth and the inhibition of cell proliferation in culture. We observed that progressively decreasing the seeding density of normal rat kidney-52E (NRK-52E) or MCF-10A epithelial cells from confluence, indeed, released cells from growth arrest. Unexpectedly, a further decrease in seeding density so that cells were isolated from neighboring cells decreased proliferation. Experiments using microengineered substrates showed that E-cadherin engagement stimulated the peak in proliferation at intermediate seeding densities, and that the proliferation arrest at high densities did not involve E-cadherin, but rather resulted from a crowding-dependent decrease in cell spreading against the underlying substrate. Rac1 activity, which was induced by E-cadherin engagement specifically at intermediate seeding densities, was required for the cadherin-stimulated proliferation, and the control of Rac1 activation by E-cadherin was mediated by p120-catenin. Together, these findings demonstrate a stimulatory role for E-cadherin in proliferative regulation, and identify a simple mechanism by which cell–cell contact may trigger or inhibit epithelial cell proliferation in different settings.
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Affiliation(s)
- Wendy F Liu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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40
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Wu H, Liang YL, Li Z, Jin J, Zhang W, Duan L, Zha X. Positive expression of E-cadherin suppresses cell adhesion to fibronectin via reduction of alpha5beta1 integrin in human breast carcinoma cells. J Cancer Res Clin Oncol 2006; 132:795-803. [PMID: 16821070 DOI: 10.1007/s00432-006-0128-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Accepted: 04/25/2006] [Indexed: 01/03/2023]
Abstract
E-cadherin mainly mediated the epithelial cell-cell adhesion, and integrin signaling can modulate the signaling pathway of E-cadherin in the different levels. Up to now, however, it is still unclear that whether E-cadherin could interfere with cell-matrix interaction, a typical adhesion through integrins. In this study we investigated the effects of E-cadherin on cell-matrix adhesion and alpha5beta1 integrin expression in human breast carcinoma cells. It was found that either mRNA or protein level of alpha5 and beta1 subunits of integrin decreased in E-cad-231 compared with Mock-231. Furthermore, the promoter activity of alpha5 gene was inhibited in E-cad-231 compared with Mock-231. Consistently, phosphorylated focal adhesion kinase, a closer key downstream protein kinase of integrin signaling, were also down-regulated in E-cad-231. Furthermore, distribution of beta-catenin was observed and data showed beta-catenin was accumulated in the nucleus in Mock-231, while disappeared from the nucleus and mainly accumulated near the cell surface membrane in E-cad-231. LiCl, a molecule that can inhibit the GSK-3beta activity and down-regulate beta-catenin degradation, could inversely stimulate expression of alpha5 and beta1 integrin. Taken together, these results indicated that positive expression of E-cadherin inhibits the cell adhesion to extracellular matrix mediated by alpha5beta1 integrin signaling.
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Affiliation(s)
- Heng Wu
- Key Laboratory of Glycoconjugate Research, Ministry of Health, Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, 138 Yi Xue Yuan Road, Shanghai, 200032, People's Republic of China
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41
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Lasaitiene D, Chen Y, Adams MA, Friberg P. Further insights into the role of angiotensin II in kidney development. Clin Physiol Funct Imaging 2006; 26:197-204. [PMID: 16836691 DOI: 10.1111/j.1475-097x.2006.00676.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Over the past decade, compelling studies have highlighted the fundamental role of the renin-angiotensin system (RAS) in renal development and long-term control of renal function and arterial pressure. The present review provides an update of the understanding of how the RAS controls nephrogenesis and nephrovascular development. In addition, the investigations linking the perinatal development of RAS inhibition-induced renal dysmorphology and establishment of adult blood pressure are discussed.
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Affiliation(s)
- Daina Lasaitiene
- Wallenberg Laboratory for Cardiovascular Research, Sahlgrenska University Hospital, University of Gothenburg, Sweden.
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42
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Matsuda T, Fujio Y, Nariai T, Ito T, Yamane M, Takatani T, Takahashi K, Azuma J. N-cadherin signals through Rac1 determine the localization of connexin 43 in cardiac myocytes. J Mol Cell Cardiol 2006; 40:495-502. [PMID: 16515795 DOI: 10.1016/j.yjmcc.2005.12.010] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2005] [Revised: 11/08/2005] [Accepted: 12/15/2005] [Indexed: 11/28/2022]
Abstract
It has been proposed that the formation of gap junction is influenced by adherens junction in cardiac myocytes. To examine whether signals through N-cadherin are involved in the distribution of connexin 43 (Cx43), the distribution of cell-cell adhesion molecules, N-cadherin and Cx43, was analyzed in aligned cardiac myocytes. To induce cell orientation running in parallel to tension direction, neonatal rat cardiac myocytes were plated for 3 hours and exposed to 20% cyclic stretch for 24 hours on silicone dishes. The aligned cells cultured for 0-5 days were immunostained with anti- N-cadherin or anti-Cx43 antibody. After cultivation for 3-5 days, following the accumulation of N-cadherin, Cx43 was localized at the longitudinal cell termini. Adenoviral gene transfer of dominant negative N-cadherin significantly attenuated the localization of Cx43 at the longitudinal cell termini, suggesting that Cx43 localization is regulated downstream of N-cadherin. In the process of Cx43 localization, Rho family proteins, RhoA and Rac1, were activated, but not Cdc42. RhoA and Rac1 activation was inhibited by the transfection of dominant negative N-cadherin, indicating that RhoA and Rac1 were activated by N-cadherin in the oriented cardiac myocytes. The inhibition of Rho family proteins by Rho GDI significantly attenuated the accumulation of Cx43, but not that of N-cadherin. Furthermore, the translocation of Cx43 to longitudinal cell termini was prevented by the inhibition of Rac1, but not RhoA. Collectively, these findings suggest that the localization of Cx43 was determined through the Rac1 pathway downstream of N-cadherin in cardiac myocytes.
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Affiliation(s)
- Takahisa Matsuda
- Department of Clinical Evaluation of Medicines and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita City, Osaka 565-0871, Japan
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43
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Aijaz S, Balda MS, Matter K. Tight junctions: molecular architecture and function. INTERNATIONAL REVIEW OF CYTOLOGY 2006; 248:261-98. [PMID: 16487793 DOI: 10.1016/s0074-7696(06)48005-0] [Citation(s) in RCA: 218] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Tight junctions are the most apical component of the epithelial junctional complex and are crucial for the formation and functioning of epithelial and endothelial barriers. They regulate selective diffusion of ions and solutes along the paracellular pathway and restrict apical/basolateral intramembrane diffusion of lipids. Research over the past years provided much insight into the molecular composition of tight junctions, and we are starting to understand the mechanisms that permit selective paracellular diffusion. Moreover, a complex network of proteins has been identified at tight junctions that is based on cytoskeleton-linked adaptors that recruit and thereby often regulate different types of signaling components that regulate epithelial proliferation, differentiation, and polarization.
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Affiliation(s)
- Saima Aijaz
- Division of Cell Biology, Institute of Ophthalmology, University College London, London, United Kingdom
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44
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Yue PYK, Wong DYL, Ha WY, Fung MC, Mak NK, Yeung HW, Leung HW, Chan K, Liu L, Fan TPD, Wong RNS. Elucidation of the mechanisms underlying the angiogenic effects of ginsenoside Rg(1) in vivo and in vitro. Angiogenesis 2005; 8:205-16. [PMID: 16328162 DOI: 10.1007/s10456-005-9000-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2005] [Revised: 04/04/2005] [Accepted: 05/31/2005] [Indexed: 01/14/2023]
Abstract
The major active constituents of ginseng are ginsenosides, and Rg(1) is a predominant compound of the total extract. Recent studies have demonstrated that Rg(1) can promote angiogenesis in vivo and in vitro. In this study, we used a DNA microarray technology to elucidate the mechanisms of action of Rg(1). We report that Rg(1) induces the proliferation of HUVECs, monitored using [(3)H]-thymidine incorporation and Trypan blue exclusion assays. Furthermore, Rg(1) (150-600 nM) also showed an enhanced tube forming inducing effect on the HUVEC. Rg(1) was also demonstrated to promote angiogenesis in an in vivo Matrigel plug assay, and increase endothelial sprouting in the ex vivo rat aorta ring assay. Differential gene expression profile of HUVEC following treatment with Rg(1) revealed the expression of genes related to cell adhesion, migration and cytoskeleton, including RhoA, RhoB, IQGAP1, CALM2, Vav2 and LAMA4. Our results suggest that Rg(1) can promote angiogenesis in multiple models, and this effect is partly due to the modulation of genes that are involved in the cytoskeletal dynamics, cell-cell adhesion and migration.
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Affiliation(s)
- Patrick Y K Yue
- Hung Lai Ching Laboratory of Biomedical Science, Research and Development Division, School of Chinese Medicine, Hong Kong Baptist University, Kowloon, Hong Kong
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45
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Walker JL, Fournier AK, Assoian RK. Regulation of growth factor signaling and cell cycle progression by cell adhesion and adhesion-dependent changes in cellular tension. Cytokine Growth Factor Rev 2005; 16:395-405. [PMID: 15886049 DOI: 10.1016/j.cytogfr.2005.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Accepted: 03/07/2005] [Indexed: 12/20/2022]
Abstract
The proliferation of most non-transformed cell types requires cell adhesion and cellular tension as well as exposure to mitogenic growth factors. Integrins and cadherins provide the adhesion signals, which ultimately allow for the cytoskeletal changes that control cellular tension. This review discusses the roles of integrins, cadherins, and the actin cytoskeleton as mediators of the mechanical tension critical for growth factor-dependent signaling and cell cycle progression.
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Affiliation(s)
- Janice L Walker
- Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, 19104-6084, USA
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46
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Jeon S, Kim S, Kim E, Lee JE, Kim SJ, Juhnn YS, Kim YS, Bae CD, Park J. Chloride Conductance Is Required for the Protein Kinase A and Rac1-dependent Phosphorylation of Moesin at Thr-558 by KCl in PC12 Cells. J Biol Chem 2005; 280:12181-9. [PMID: 15634677 DOI: 10.1074/jbc.m408253200] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Moesin is a member of the ERM family, a family of cross-linkers between the plasma membrane and the actin cytoskeleton, which are known to be activated by phosphorylation. Previously, we reported the RhoA and Rho kinase-dependent phosphorylation of moesin at Thr-558 in hippocampal neuronal cells by glutamate. Here we studied the induction of moesin phosphorylation by KCl (60 mm) in PC12 cells. Moesin phosphorylation at Thr-558 was increased after 2 min of KCl treatment, peaked at 5 min, and returned to the basal level by 60 min. KCl also activated Rac1, but not RhoA, in PC12 cells, and KCl-induced moesin phosphorylation was suppressed in dominant negative Rac1 (N17 Rac1)-expressed cells. The inhibition of protein kinase A (PKA), known as an upstream kinase of Rac1, abolished Rac1 activation and moesin phosphorylation by KCl. Interestingly, the phosphorylation of moesin by KCl was independent of KCl-induced membrane depolarization and calcium influx but was dependent on KCl-induced chloride conductance. 60 mm KCl induced chloride conductance in PC12 cells, and pretreatment with Cl- channel blocker abolished Rac1 activation and moesin phosphorylation by KCl. These results suggest that the phosphorylation of moesin at Thr-558 in PC12 cells by KCl treatment is PKA- and Rac1-dependent and that KCl-induced chloride conductance is involved in the activation of this signaling system.
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Affiliation(s)
- Songhee Jeon
- Department of Molecular Cell Biology, Samsung Biomedical Research Institute, and Center for Neuronal Cell Excitability Research, Sungkyunkwan University School of Medicine, Suwon 440-746, Korea
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47
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Cohen M, Joester D, Geiger B, Addadi L. Spatial and temporal sequence of events in cell adhesion: from molecular recognition to focal adhesion assembly. Chembiochem 2005; 5:1393-9. [PMID: 15457530 DOI: 10.1002/cbic.200400162] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A new concept that attributes a pivotal role to the pericellular coat in the regulation of the early stages of cell adhesion is presented. Quick, adaptable, and transient adhesion through multiple cooperative weak interactions provides the cell with an additional level of modulation in the decision-making process that precedes the commitment to adhesion at a particular site. Hyaluronan emerges as a modulator of cell adhesion in certain cells, mediating binding or repulsion through its polyelectrolyte character, in addition to its chirality and molecular-recognition properties. The biophysical properties of hyaluronan as well as its ultrastructural organization are analyzed in relation to this proposed function.
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Affiliation(s)
- Miriam Cohen
- Department of Molecular Cell Biology, Weizmann Institute of Science, Rehovot 76100, Israel
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48
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Brunton VG, MacPherson IRJ, Frame MC. Cell adhesion receptors, tyrosine kinases and actin modulators: a complex three-way circuitry. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2004; 1692:121-44. [PMID: 15246683 DOI: 10.1016/j.bbamcr.2004.04.010] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2004] [Accepted: 04/19/2004] [Indexed: 12/31/2022]
Abstract
The interaction of cells with surrounding matrix and neighbouring cells governs many aspects of cell behaviour. Aside from transmitting signals from the external environment, adhesion receptors also receive signals from the cell interior. Here we review the interrelationship between adhesion receptors, tyrosine kinases (both growth factor receptor and non-receptor) and modulators of the actin cytoskeletal network. Deregulation of many aspects of these signalling pathways in cancer highlights the need for a better understanding of the complexities involved.
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Affiliation(s)
- V G Brunton
- The Beatson Institute for Cancer Research, Cancer Research UK Beatson Laboratories, Garscube Estate, Switchback Road, Bearsden, Glasgow G61 1BD.
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Mruk DD, Cheng CY. Sertoli-Sertoli and Sertoli-germ cell interactions and their significance in germ cell movement in the seminiferous epithelium during spermatogenesis. Endocr Rev 2004; 25:747-806. [PMID: 15466940 DOI: 10.1210/er.2003-0022] [Citation(s) in RCA: 614] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Spermatogenesis is the process by which a single spermatogonium develops into 256 spermatozoa, one of which will fertilize the ovum. Since the 1950s when the stages of the epithelial cycle were first described, reproductive biologists have been in pursuit of one question: How can a spermatogonium traverse the epithelium, while at the same time differentiating into elongate spermatids that remain attached to the Sertoli cell throughout their development? Although it was generally agreed upon that junction restructuring was involved, at that time the types of junctions present in the testis were not even discerned. Today, it is known that tight, anchoring, and gap junctions are found in the testis. The testis also has two unique anchoring junction types, the ectoplasmic specialization and tubulobulbar complex. However, attention has recently shifted on identifying the regulatory molecules that "open" and "close" junctions, because this information will be useful in elucidating the mechanism of germ cell movement. For instance, cytokines have been shown to induce Sertoli cell tight junction disassembly by shutting down the production of tight junction proteins. Other factors such as proteases, protease inhibitors, GTPases, kinases, and phosphatases also come into play. In this review, we focus on this cellular phenomenon, recapping recent developments in the field.
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Affiliation(s)
- Dolores D Mruk
- Population Council, Center for Biomedical Research, New York, New York 10021, USA.
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Uhlenbrock K, Eberth A, Herbrand U, Daryab N, Stege P, Meier F, Friedl P, Collard JG, Ahmadian MR. The RacGEF Tiam1 inhibits migration and invasion of metastatic melanoma via a novel adhesive mechanism. J Cell Sci 2004; 117:4863-71. [PMID: 15340013 DOI: 10.1242/jcs.01367] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Rho-like GTPases such as RhoA, Rac1 and Cdc42 are key regulators of actin-dependent cell functions including cell morphology, adhesion and migration. Tiam1 (T lymphoma invasion and metastasis 1), a guanine nucleotide exchange factor that activates Rac, is an important regulator of cell shape and invasiveness in epithelial cells and fibroblasts. Overexpression of Tiam1 in metastatic melanoma cells converted the constitutive mesenchymal phenotype into an epithelial-like phenotype. This included the induction of stringent cell-cell contacts mediated by the Ig-like receptor ALCAM (activated leukocyte cell adhesion molecule) and actin redistribution to cell-cell junctions. This phenotypic switch was dependent on increased Rac but not Rho activity, and on the redistribution and adhesive function of ALCAM, whereas cadherins were not involved. Although cell proliferation was significantly enhanced, the gain of cell-cell junctions strongly counteracted cell motility and invasion as shown for two- and three-dimensional collagen assays as well as invasion into human skin reconstructs. The reverse transition from mesenchymal invasive to a resident epithelial-like phenotype implicates a role for Tiam1/Rac signaling in the control of cell-cell contacts through a novel ALCAM-mediated mechanism.
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Affiliation(s)
- Katharina Uhlenbrock
- Department of Structural Biology, Max-Planck-Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany
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