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Sample records for affect cell migration

  1. How does cancer cell metabolism affect tumor migration and invasion?

    PubMed

    Han, Tianyu; Kang, De; Ji, Daokun; Wang, Xiaoyu; Zhan, Weihua; Fu, Minggui; Xin, Hong-Bo; Wang, Jian-Bin

    2013-01-01

    Cancer metastasis is the major cause of cancer-associated death. Accordingly, identification of the regulatory mechanisms that control whether or not tumor cells become "directed walkers" is a crucial issue of cancer research. The deregulation of cell migration during cancer progression determines the capacity of tumor cells to escape from the primary tumors and invade adjacent tissues to finally form metastases. The ability to switch from a predominantly oxidative metabolism to glycolysis and the production of lactate even when oxygen is plentiful is a key characteristic of cancer cells. This metabolic switch, known as the Warburg effect, was first described in 1920s, and affected not only tumor cell growth but also tumor cell migration. In this review, we will focus on the recent studies on how cancer cell metabolism affects tumor cell migration and invasion. Understanding the new aspects on molecular mechanisms and signaling pathways controlling tumor cell migration is critical for development of therapeutic strategies for cancer patients.

  2. How Tissue Mechanical Properties Affect Enteric Neural Crest Cell Migration

    NASA Astrophysics Data System (ADS)

    Chevalier, N. R.; Gazguez, E.; Bidault, L.; Guilbert, T.; Vias, C.; Vian, E.; Watanabe, Y.; Muller, L.; Germain, S.; Bondurand, N.; Dufour, S.; Fleury, V.

    2016-02-01

    Neural crest cells (NCCs) are a population of multipotent cells that migrate extensively during vertebrate development. Alterations to neural crest ontogenesis cause several diseases, including cancers and congenital defects, such as Hirschprung disease, which results from incomplete colonization of the colon by enteric NCCs (ENCCs). We investigated the influence of the stiffness and structure of the environment on ENCC migration in vitro and during colonization of the gastrointestinal tract in chicken and mouse embryos. We showed using tensile stretching and atomic force microscopy (AFM) that the mesenchyme of the gut was initially soft but gradually stiffened during the period of ENCC colonization. Second-harmonic generation (SHG) microscopy revealed that this stiffening was associated with a gradual organization and enrichment of collagen fibers in the developing gut. Ex-vivo 2D cell migration assays showed that ENCCs migrated on substrates with very low levels of stiffness. In 3D collagen gels, the speed of the ENCC migratory front decreased with increasing gel stiffness, whereas no correlation was found between porosity and ENCC migration behavior. Metalloprotease inhibition experiments showed that ENCCs actively degraded collagen in order to progress. These results shed light on the role of the mechanical properties of tissues in ENCC migration during development.

  3. How Tissue Mechanical Properties Affect Enteric Neural Crest Cell Migration

    PubMed Central

    Chevalier, N.R.; Gazguez, E.; Bidault, L.; Guilbert, T.; Vias, C.; Vian, E.; Watanabe, Y.; Muller, L.; Germain, S.; Bondurand, N.; Dufour, S.; Fleury, V.

    2016-01-01

    Neural crest cells (NCCs) are a population of multipotent cells that migrate extensively during vertebrate development. Alterations to neural crest ontogenesis cause several diseases, including cancers and congenital defects, such as Hirschprung disease, which results from incomplete colonization of the colon by enteric NCCs (ENCCs). We investigated the influence of the stiffness and structure of the environment on ENCC migration in vitro and during colonization of the gastrointestinal tract in chicken and mouse embryos. We showed using tensile stretching and atomic force microscopy (AFM) that the mesenchyme of the gut was initially soft but gradually stiffened during the period of ENCC colonization. Second-harmonic generation (SHG) microscopy revealed that this stiffening was associated with a gradual organization and enrichment of collagen fibers in the developing gut. Ex-vivo 2D cell migration assays showed that ENCCs migrated on substrates with very low levels of stiffness. In 3D collagen gels, the speed of the ENCC migratory front decreased with increasing gel stiffness, whereas no correlation was found between porosity and ENCC migration behavior. Metalloprotease inhibition experiments showed that ENCCs actively degraded collagen in order to progress. These results shed light on the role of the mechanical properties of tissues in ENCC migration during development. PMID:26887292

  4. Iodine Affects Differentiation and Migration Process in Trophoblastic Cells.

    PubMed

    Olivo-Vidal, Zendy Evelyn; Rodríguez, Roció Coutiño; Arroyo-Helguera, Omar

    2016-02-01

    Iodine deficiency is associated with oxidative stress increase and preeclampsia during gestation, suggesting that iodine concentration plays an important role in the normal placenta physiology. The question raised is to analyze the effect of iodine deficiency on oxidative stress, viability, differentiation, and migration process and changes in the expression of differentiation and migration markers. Iodine deprivation was done using potassium perchlorate (KCLO4) to block sodium iodide symporter (NIS) transporter and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid DIDS to inhibit pendrine (PEN) transport for 3-48 h. Then trophoblast cells were treated with low iodine doses of 5-500 μM and high iodine doses of 100-5000 μM. Oxidative stress, viability, and human chorionic gonadotropin (hGC) were measured by colorimetric methods. Migration throphoblast cells were evaluated by both wound healing and Boyden chamber assays. Changes in mRNA expression were analyzed by real-time RT-PCR. Iodine deprivation induces a significant increase of reactive oxygen species (ROS), viability, and migration process vs control cells. We found a significant overregulation in the mRNA's peroxisome proliferator-activated receptor (PPAR-gamma), Snail, and matrix metalloproteinase-9 (MMP-9) mRNA's in cells deprived of iodine, as well as a down glial cell missing-1 (GCM-1) regulation, hGC, pregnancy-associated plasma protein-A (PAPP-A), and E-cadherin mRNA expression. The expression of hypoxic induction factor alpha (HIFα) mRNA does not change with iodine deprivation. In cells deprived of iodine, supplementing low iodine doses (5-500 μM) does not induce any significant changes in viability. However, ROS and migration process were decreased, although we found an increased human chorionic gonadotropin (hCG) secretion as a differentiation marker. In addition, we found that PPAR-gamma, Snail, and MPP-9 mRNAs expression are downregulated with low iodine doses, in contrast with GCM-1, PAPP

  5. Anabolic androgens affect the competitive interactions in cell migration and adhesion between normal mouse urothelial cells and urothelial carcinoma cells.

    PubMed

    Huang, Chi-Ping; Hsieh, Teng-Fu; Chen, Chi-Cheng; Hung, Xiao-Fan; Yu, Ai-Lin; Chang, Chawnshang; Shyr, Chih-Rong

    2014-09-26

    The urothelium is constantly rebuilt by normal urothelial cells to regenerate damaged tissues caused by stimuli in urine. However, the urothelial carcinoma cells expand the territory by aberrant growth of tumor cells, which migrate and occupy the damaged tissues to spread outside and disrupt the normal cells and organized tissues and form a tumor. Therefore, the interaction between normal urothelial cells and urothelial carcinoma cells affect the initiation and progression of urothelial tumors if normal urothelial cells fail to migrate and adhere to the damages sites to regenerate the tissues. Here, comparing normal murine urothelial cells with murine urothelial carcinoma cells (MBT-2), we found that normal cells had less migration ability than carcinoma cells. And in our co-culture system we found that carcinoma cells had propensity migrating toward normal urothelial cells and carcinoma cells had more advantages to adhere than normal cells. To reverse this condition, we used anabolic androgen, dihyrotestosterone (DHT) to treat normal cells and found that DHT treatment increased the migration ability of normal urothelial cells toward carcinoma cells and the adhesion capacity in competition with carcinoma cells. This study provides the base of a novel therapeutic approach by using anabolic hormone-enforced normal urothelial cells to regenerate the damage urothelium and defend against the occupancy of carcinoma cells to thwart cancer development and recurrence.

  6. Cell Migration

    PubMed Central

    Trepat, Xavier; Chen, Zaozao; Jacobson, Ken

    2015-01-01

    Cell migration is fundamental to establishing and maintaining the proper organization of multicellular organisms. Morphogenesis can be viewed as a consequence, in part, of cell locomotion, from large-scale migrations of epithelial sheets during gastrulation, to the movement of individual cells during development of the nervous system. In an adult organism, cell migration is essential for proper immune response, wound repair, and tissue homeostasis, while aberrant cell migration is found in various pathologies. Indeed, as our knowledge of migration increases, we can look forward to, for example, abating the spread of highly malignant cancer cells, retarding the invasion of white cells in the inflammatory process, or enhancing the healing of wounds. This article is organized in two main sections. The first section is devoted to the single-cell migrating in isolation such as occurs when leukocytes migrate during the immune response or when fibroblasts squeeze through connective tissue. The second section is devoted to cells collectively migrating as part of multicellular clusters or sheets. This second type of migration is prevalent in development, wound healing, and in some forms of cancer metastasis. PMID:23720251

  7. Golgi Anti-apoptotic Proteins Are Highly Conserved Ion Channels That Affect Apoptosis and Cell Migration*

    PubMed Central

    Carrara, Guia; Saraiva, Nuno; Parsons, Maddy; Byrne, Bernadette; Prole, David L.; Taylor, Colin W.; Smith, Geoffrey L.

    2015-01-01

    Golgi anti-apoptotic proteins (GAAPs) are multitransmembrane proteins that are expressed in the Golgi apparatus and are able to homo-oligomerize. They are highly conserved throughout eukaryotes and are present in some prokaryotes and orthopoxviruses. Within eukaryotes, GAAPs regulate the Ca2+ content of intracellular stores, inhibit apoptosis, and promote cell adhesion and migration. Data presented here demonstrate that purified viral GAAPs (vGAAPs) and human Bax inhibitor 1 form ion channels and that vGAAP from camelpox virus is selective for cations. Mutagenesis of vGAAP, including some residues conserved in the recently solved structure of a related bacterial protein, BsYetJ, altered the conductance (E207Q and D219N) and ion selectivity (E207Q) of the channel. Mutation of residue Glu-207 or -178 reduced the effects of GAAP on cell migration and adhesion without affecting protection from apoptosis. In contrast, mutation of Asp-219 abrogated the anti-apoptotic activity of GAAP but not its effects on cell migration and adhesion. These results demonstrate that GAAPs are ion channels and define residues that contribute to the ion-conducting pore and affect apoptosis, cell adhesion, and migration independently. PMID:25713081

  8. Characterization of the activities of actin-affecting drugs on tumor cell migration

    SciTech Connect

    Hayot, Caroline; Debeir, Olivier; Ham, Philippe van; Damme, Marc van; Kiss, Robert; Decaestecker, Christine . E-mail: cdecaes@ulb.ac.be

    2006-02-15

    Metastases kill 90% of cancer patients. It is thus a major challenge in cancer therapy to inhibit the spreading of tumor cells from primary tumor sites to those particular organs where metastases are likely to occur. Whereas the actin cytoskeleton is a key component involved in cell migration, agents targeting actin dynamics have been relatively poorly investigated. Consequently, valuable in vitro pharmacological tools are needed to selectively identify this type of agent. In response to the absence of any standardized process, the present work aims to develop a multi-assay strategy for screening actin-affecting drugs with anti-migratory potentials. To validate our approach, we used two cancer cell lines (MCF7 and A549) and three actin-affecting drugs (cytochalasin D, latrunculin A, and jasplakinolide). We quantified the effects of these drugs on the kinetics of actin polymerization in tubes (by means of spectrofluorimetry) and on the dynamics of actin cytoskeletons within whole cells (by means of fluorescence microscopy). Using quantitative videomicroscopy, we investigated the actual effects of the drugs on cell motility. Finally, the combined drug effects on cell motility and cell growth were evaluated by means of a scratch-wound assay. While our results showed concordant drug-induced effects on actin polymerization occurring in vitro in test tubes and within whole cells, the whole cell assay appeared more sensitive than the tube assay. The inhibition of actin polymerization induced by cytochalasin D was paralleled by a decrease in cell motility for both cell types. In the case of jasplakinolide, which induces actin polymerization, while it significantly enhanced the locomotion of the A549 cells, it significantly inhibited that of the MCF-7 ones. All these effects were confirmed by means of the scratch-wound assay except of the jasplakinolide-induced effects on MCF-7 cell motility. These later seemed compensated by an additional effect occurring during wound

  9. Slits Affect the Timely Migration of Neural Crest Cells via Robo Receptor

    PubMed Central

    Giovannone, Dion; Reyes, Michelle; Reyes, Rachel; Correa, Lisa; Martinez, Darwin; Ra, Hannah; Gomez, Gustavo; Kaiser, Josh; Ma, Le; Stein, Mary-Pat; de Bellard, Maria Elena

    2013-01-01

    SUMMARY Background Neural crest cells emerge by delamination from the dorsal neural tube and give rise to various components of the peripheral nervous system in vertebrate embryos. These cells change from non-motile into highly motile cells migrating to distant areas before further differentiation. Mechanisms controlling delamination and subsequent migration of neural crest cells are not fully understood. Slit2, a chemorepellant for axonal guidance that repels and stimulates motility of trunk neural crest cells away from the gut has recently been suggested to be a tumor suppressor molecule. The goal of this study was to further investigate the role of Slit2 in trunk neural crest cell migration by constitutive expression in neural crest cells. Results We found that Slit gain-of-function significantly impaired neural crest cell migration while Slit loss-of-function favored migration. In addition, we observed that the distribution of key cytoskeletal markers was disrupted in both gain and loss of function instances. Conclusions These findings suggest that Slit molecules might be involved in the processes that allow neural crest cells to begin migration and transitioning to a mesenchymal type. PMID:22689303

  10. Axitinib affects cell viability and migration of a primary foetal lung adenocarcinoma culture.

    PubMed

    Menna, Cecilia; De Falco, Elena; Pacini, Luca; Scafetta, Gaia; Ruggieri, Paola; Puca, Rosa; Petrozza, Vincenzo; Ciccone, Anna Maria; Rendina, Erino Angelo; Calogero, Antonella; Ibrahim, Mohsen

    2014-01-01

    Fetal lung adenocarcinoma (FLAC) is a rare variant of lung adenocarcinoma. Studies regarding FLAC have been based only on histopathological observations, thus representative in vitro models of FLAC cultures are unavailable. We have established and characterized a human primary FLAC cell culture, exploring its biology, chemosensitivity, and migration. FLAC cells and specimen showed significant upregulation of VEGF165 and HIF-1α mRNA levels. This observation was confirmed by in vitro chemosensitivity and migration assay, showing that only Axitinib was comparable to Cisplatin treatment. We provide a suitable in vitro model to further investigate the nature of this rare type of cancer. PMID:24380379

  11. Defective neuroepithelial cell cohesion affects tangential branchiomotor neuron migration in the zebrafish neural tube.

    PubMed

    Stockinger, Petra; Maître, Jean-Léon; Heisenberg, Carl-Philipp

    2011-11-01

    Facial branchiomotor neurons (FBMNs) in zebrafish and mouse embryonic hindbrain undergo a characteristic tangential migration from rhombomere (r) 4, where they are born, to r6/7. Cohesion among neuroepithelial cells (NCs) has been suggested to function in FBMN migration by inhibiting FBMNs positioned in the basal neuroepithelium such that they move apically between NCs towards the midline of the neuroepithelium instead of tangentially along the basal side of the neuroepithelium towards r6/7. However, direct experimental evaluation of this hypothesis is still lacking. Here, we have used a combination of biophysical cell adhesion measurements and high-resolution time-lapse microscopy to determine the role of NC cohesion in FBMN migration. We show that reducing NC cohesion by interfering with Cadherin 2 (Cdh2) activity results in FBMNs positioned at the basal side of the neuroepithelium moving apically towards the neural tube midline instead of tangentially towards r6/7. In embryos with strongly reduced NC cohesion, ectopic apical FBMN movement frequently results in fusion of the bilateral FBMN clusters over the apical midline of the neural tube. By contrast, reducing cohesion among FBMNs by interfering with Contactin 2 (Cntn2) expression in these cells has little effect on apical FBMN movement, but reduces the fusion of the bilateral FBMN clusters in embryos with strongly diminished NC cohesion. These data provide direct experimental evidence that NC cohesion functions in tangential FBMN migration by restricting their apical movement.

  12. Heparan Sulfate Proteoglycans May Promote or Inhibit Cancer Progression by Interacting with Integrins and Affecting Cell Migration

    PubMed Central

    Soares, Mariana A.; Teixeira, Felipe C. O. B.; Fontes, Miguel; Arêas, Ana Lúcia; Leal, Marcelo G.; Pavão, Mauro S. G.; Stelling, Mariana P.

    2015-01-01

    The metastatic disease is one of the main consequences of tumor progression, being responsible for most cancer-related deaths worldwide. This review intends to present and discuss data on the relationship between integrins and heparan sulfate proteoglycans in health and cancer progression. Integrins are a family of cell surface transmembrane receptors, responsible for cell-matrix and cell-cell adhesion. Integrins' main functions include cell adhesion, migration, and survival. Heparan sulfate proteoglycans (HSPGs) are cell surface molecules that play important roles as cell receptors, cofactors, and overall direct or indirect contributors to cell organization. Both molecules can act in conjunction to modulate cell behavior and affect malignancy. In this review, we will discuss the different contexts in which various integrins, such as α5, αV, β1, and β3, interact with HSPGs species, such as syndecans and perlecans, affecting tissue homeostasis. PMID:26558271

  13. Plakophilin 2 Affects Cell Migration by Modulating Focal Adhesion Dynamics and Integrin Protein Expression

    PubMed Central

    Koetsier, Jennifer L.; Amargo, Evangeline V.; Todorović, Viktor; Green, Kathleen J.; Godsel, Lisa M.

    2014-01-01

    Plakophilin 2 (PKP2), a desmosome component, modulates the activity and localization of the small GTPase RhoA at sites of cell–cell contact. PKP2 regulates cortical actin rearrangement during junction formation, and its loss is accompanied by an increase in actin stress fibers. We hypothesized that PKP2 may regulate focal adhesion dynamics and cell migration. Here we show that PKP2-deficient cells bind efficiently to the extracellular matrix, but upon spreading display total cell areas ~30% smaller than control cells. Focal adhesions in PKP2-deficient cells are ~2× larger and more stable than in control cells, and vinculin displays an increased time for fluorescence recovery after photobleaching. Furthermore, β4 and β1 integrin protein and mRNA expression is elevated in PKP2-silenced cells. Normal focal adhesion phenotypes can be restored in PKP2-null cells by dampening the RhoA pathway or silencing β1 integrin. However, integrin expression levels are not restored by RhoA signaling inhibition. These data uncover a potential role for PKP2 upstream of β1 integrin and RhoA in integrating cell–cell and cell–substrate contact signaling in basal keratinocytes necessary for the morphogenesis, homeostasis, and reepithelialization of the stratified epidermis. PMID:23884246

  14. Γ-aminobutyric acid receptors affect the progression and migration of tumor cells.

    PubMed

    Zhang, Xiaoxue; Du, Zuoyi; Liu, Jun; He, Jianxing

    2014-12-01

    Γ-aminobutyric acid (GABA) is a multifunctional molecule found in the nervous system and non-neuronal tissues. GABA receptors combine with GABA molecules and transmit signal stimuli into cells. In addition to traditional neurotransmission and regulation of secretion, GABA and GABA receptors are involved in cell differentiation and proliferation throughout peripheral organs, as well as in tumorigenesis. The exact mechanism of the GABAergic system in regulating tumor development is unclear, but many studies have revealed that GABA receptors exert critical regulative effects on tumor cell proliferation and migration. In this review, the molecular structure, distribution and biological function of GABA receptors associated with tumorigenesis are described. Recent advances in the elucidation of mechanisms underlying GABAergic signaling control over tumor growth are also discussed.

  15. Cyclin-dependent kinase-mediated phosphorylation of breast cancer metastasis suppressor 1 (BRMS1) affects cell migration.

    PubMed

    Roesley, Siti Nur Ain; Suryadinata, Randy; Morrish, Emma; Tan, Anthonius Ricardo; Issa, Samah M A; Oakhill, Jonathan S; Bernard, Ora; Welch, Danny R; Šarčević, Boris

    2016-01-01

    Expression of Breast Cancer Metastasis Suppressor 1 (BRMS1) reduces the incidence of metastasis in many human cancers, without affecting tumorigenesis. BRMS1 carries out this function through several mechanisms, including regulation of gene expression by binding to the mSin3/histone deacetylase (HDAC) transcriptional repressor complex. In the present study, we show that BRMS1 is a novel substrate of Cyclin-Dependent Kinase 2 (CDK2) that is phosphorylated on serine 237 (S237). Although CDKs are known to regulate cell cycle progression, the mutation of BRMS1 on serine 237 did not affect cell cycle progression and proliferation of MDA-MB-231 breast cancer cells; however, their migration was affected. Phosphorylation of BRMS1 does not affect its association with the mSin3/HDAC transcriptional repressor complex or its transcriptional repressor activity. The serine 237 phosphorylation site is immediately proximal to a C-terminal nuclear localization sequence that plays an important role in BRMS1-mediated metastasis suppression but phosphorylation does not control BRMS1 subcellular localization. Our studies demonstrate that CDK-mediated phosphorylation of BRMS1 regulates the migration of tumor cells.

  16. Aquaporins and cell migration.

    PubMed

    Papadopoulos, M C; Saadoun, S; Verkman, A S

    2008-07-01

    Aquaporin (AQP) water channels are expressed primarily in cell plasma membranes. In this paper, we review recent evidence that AQPs facilitate cell migration. AQP-dependent cell migration has been found in a variety of cell types in vitro and in mice in vivo. AQP1 deletion reduces endothelial cell migration, limiting tumor angiogenesis and growth. AQP4 deletion slows the migration of reactive astrocytes, impairing glial scarring after brain stab injury. AQP1-expressing tumor cells have enhanced metastatic potential and local infiltration. Impaired cell migration has also been seen in AQP1-deficient proximal tubule epithelial cells, and AQP3-deficient corneal epithelial cells, enterocytes, and skin keratinocytes. The mechanisms by which AQPs enhance cell migration are under investigation. We propose that, as a consequence of actin polymerization/depolymerization and transmembrane ionic fluxes, the cytoplasm adjacent to the leading edge of migrating cells undergoes rapid changes in osmolality. AQPs could thus facilitate osmotic water flow across the plasma membrane in cell protrusions that form during migration. AQP-dependent cell migration has potentially broad implications in angiogenesis, tumor metastasis, wound healing, glial scarring, and other events requiring rapid, directed cell movement. AQP inhibitors may thus have therapeutic potential in modulating these events, such as slowing tumor growth and spread, and reducing glial scarring after injury to allow neuronal regeneration. PMID:17968585

  17. Heparin-disaccharide affects T cells: inhibition of NF-kappaB activation, cell migration, and modulation of intracellular signaling.

    PubMed

    Hecht, Iris; Hershkoviz, Rami; Shivtiel, Shoham; Lapidot, Tzvi; Cohen, Irun R; Lider, Ofer; Cahalon, Liora

    2004-06-01

    We previously reported that disaccharides (DS), generated by enzymatic degradation of heparin or heparan sulfate, inhibit T cell-mediated immune reactions in rodents and regulate cytokine [tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-8, and IL-1beta] secretion by T cells, macrophages, or intestinal epithelial cells. Here, we investigated the effects of a trisulfated heparin DS (3S-DS) on two aspects of T cell function: secretion of proinflammatory cytokines and migration to an inflamed site. 3S-DS down-regulated nuclear factor-kappaB activity and reduced the secretion of TNF-alpha and interferon-gamma (IFN-gamma) by anti-CD3-activated T cells. In addition, 3S-DS inhibited CXC chemokine ligand 12 (CXCL12; stromal cell-derived factor-1alpha)-dependent migration in vitro and in vivo and decreased CXCL12-induced T cell adhesion to the extracellular matrix glycoprotein, fibronectin (FN). This inhibition was accompanied by attenuation of CXCL12-induced Pyk2 phosphorylation but did not involve internalization of the CXCL12 receptor, CXCR4, or phosphorylation of extracellular-regulated kinase. Despite inhibiting CXCL12-induced adhesion, 3S-DS, on its own, induced T cell adhesion to FN, which was accompanied by phosphorylation of Pyk2. A monosulfated DS showed no effect. Taken together, these data provide evidence that 3S-DS can regulate inflammation by inducing and modulating T cell-signaling events, desensitizing CXCR4, and modulating T cell receptor-induced responses. PMID:15020655

  18. Prenatal Hypoxia in Different Periods of Embryogenesis Differentially Affects Cell Migration, Neuronal Plasticity, and Rat Behavior in Postnatal Ontogenesis

    PubMed Central

    Vasilev, Dmitrii S.; Dubrovskaya, Nadezhda M.; Tumanova, Natalia L.; Zhuravin, Igor A.

    2016-01-01

    Long-term effects of prenatal hypoxia on embryonic days E14 or E18 on the number, type and localization of cortical neurons, density of labile synaptopodin-positive dendritic spines, and parietal cortex-dependent behavioral tasks were examined in the postnatal ontogenesis of rats. An injection of 5′ethynyl-2′deoxyuridine to pregnant rats was used to label neurons generated on E14 or E18 in the fetuses. In control rat pups a majority of cells labeled on E14 were localized in the lower cortical layers V-VI while the cells labeled on E18 were mainly found in the superficial cortical layers II-III. It was shown that hypoxia both on E14 and E18 results in disruption of neuroblast generation and migration but affects different cell populations. In rat pups subjected to hypoxia on E14, the total number of labeled cells in the parietal cortex was decreased while the number of labeled neurons scattered within the superficial cortical layers was increased. In rat pups subjected to hypoxia on E18, the total number of labeled cells in the parietal cortex was also decreased but the number of scattered labeled neurons was higher in the lower cortical layers. It can be suggested that prenatal hypoxia both on E14 and E18 causes a disruption in neuroblast migration but with a different outcome. Only in rats subjected to hypoxia on E14 did we observe a reduction in the total number of pyramidal cortical neurons and the density of labile synaptopodin-positive dendritic spines in the molecular cortical layer during the first month after birth which affected development of the cortical functions. As a result, rats subjected to hypoxia on E14, but not on E18, had impaired development of the whisker-placing reaction and reduced ability to learn reaching by a forepaw. The data obtained suggest that hypoxia on E14 in the period of generation of the cells, which later differentiate into the pyramidal cortical neurons of the V-VI layers and form cortical minicolumns, affects formation of

  19. IAPs and cell migration.

    PubMed

    Dubrez, Laurence; Rajalingam, Krishnaraj

    2015-03-01

    Inhibitors of apoptosis (IAPs) constitute a family of cell signaling regulators controlling several fundamental biological processes such as innate immunity, inflammation, cell death, cell proliferation, and cell differentiation. Increasing evidence from in vivo and in vitro studies indicate a function for IAPs in the modulation of invasive and migratory properties of cells. Here, we present and discuss the mechanisms whereby IAPs can control cell migration.

  20. Integrin-linked kinase affects signaling pathways and migration in thyroid cancer cells and is a potential therapeutic target

    PubMed Central

    Shirley, Lawrence A.; McCarty, Samantha; Yang, Ming-Chen; Saji, Motoyasu; Zhang, Xiaoli; Phay, John; Ringel, Matthew D.; Chen, Ching-Shih

    2016-01-01

    Background Integrin-linked kinase (ILK) is a serine-threonine kinase that regulates interactions between the cell and the extracellular matrix. In many cancers, overexpression of ILK leads to increased cell proliferation, motility, and invasion. We hypothesized that ILK functions as a regulator of viability and migration in thyroid cancer cells. Methods Eleven human thyroid cancer cell lines were screened for ILK protein expression. The cell lines with the greatest expression were treated with either ILK small interfering RNA (siRNA) or a novel ILK inhibitor, T315, and the effects were evaluated via Western blot and migration assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays were performed to assess cell viability. Results siRNA against ILK decreased phosphorylation of downstream effectors Akt and MLC, as well as decreased migration. Treatment with T315 showed a dose-related decrease in both Akt and MLC phosphorylation, as well as decreased migration. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays showed T315 to have an half maximal inhibitory concentration of less than 1 µM in cell lines with high ILK expression. Conclusion ILK is expressed differentially in thyroid cancer cell lines. Both ILK siRNA and T315 inhibit motility of thyroid cancer cell lines, and T315 is shown to be cytotoxic at low concentrations. Altogether, our study suggests that ILK may represent an important kinase in aggressive thyroid cancers. PMID:26549818

  1. Interleukin-1β Affects MDAMB231 Breast Cancer Cell Migration under Hypoxia: Role of HIF-1α and NFκB Transcription Factors.

    PubMed

    Filippi, Irene; Carraro, Fabio; Naldini, Antonella

    2015-01-01

    Inflammation and tumor hypoxia are intimately linked and breast cancer provides a typical example of an inflammation-linked malignant disease. Indeed, breast cancer progression is actively supported by inflammatory components, including IL-1β, and by the hypoxia-inducible factor- (HIF-) 1α. In spite of many attempts where the role of either IL-1β or HIF-1α was evaluated, detailed mechanisms for their effects on breast cancer cell migration under hypoxia are still unclear. We here report that IL-1β increased MDAMB231 cell migration under hypoxic conditions along with HIF-1α accumulation and upregulation of CXCR1, which is transcriptionally regulated by HIF-1α, as well as an increased expression of CXCL8 and NFκB. In addition, IL-1β-induced cell migration in hypoxia was not affected when HIF-1α was inhibited by either siRNA or Topotecan, well known for its inhibitory effect on HIF-1α. Of interest, HIF-1α inhibition did not reduce NFκB and CXCL8 expression and the reduction of IL-1β-induced cell migration under hypoxia was achieved only by pharmacological inhibition of NFκB. Our findings indicate that inhibition of HIF-1α does not prevent the migratory program activated by IL-1β in hypoxic MDAMB231 cells. They also suggest a potential compensatory role of NFκB/CXCL8 pathway in IL-1β-induced MDAMB231 cell migration in a hypoxic microenvironment.

  2. MicroRNA-144 affects radiotherapy sensitivity by promoting proliferation, migration and invasion of breast cancer cells.

    PubMed

    Yu, Lei; Yang, Yanming; Hou, Jiguang; Zhai, Chengwei; Song, Yunhao; Zhang, Zhiliang; Qiu, Ling; Jia, Xiaojing

    2015-10-01

    Radiotherapy resistance remains a major obstacle for patients with breast cancer. miRNAs are important regulators in many biological processes including proliferation, apoptosis, invasion and metastasis and response to treatment in different types of tumors. Here, we describe the role of miRNA-144 in the regulation of radiotherapy sensitivity, migration and invasion of breast cancer cells. The cell survival rate of breast cancer cells was measured by WST-1 assay after irradiation. The caspase-3/-7 activity and apoptotic proteins were analyzed by Caspase-Glo3/7 assay and western blot analysis, respectively. The migration and invasion of breast cancer cells were evaluated by BD Transwell migration and Matrigel invasion assays. The EMT markers were detected by western blot analysis. We found that overexpression of miR-144 increased the proliferation rate of MDA-MB-231 cells without radiation. Both MDA-MB‑231 and SKBR3 cells exhibited significantly increased radiation resistance after overexpression of miR-144. Meanwhile, the migration and invasion of both MDA-MB-231 and SKBR3 cells were changed by altered miR-144 expression. In addition, the overexpression of miR-144 inhibited E-cadherin expression and promoted Snail expression. miR-144 activated AKT by downregulation of PTEN in breast cancer cells. Our results strongly suggest that miR-144 acts as an important regulator of tumorigenesis and tumor progression of breast cancer. These results indicate that miR-144 might serve as a potential molecular target for breast cancer treatment.

  3. Aptamer targeting EGFRvIII mutant hampers its constitutive autophosphorylation and affects migration, invasion and proliferation of glioblastoma cells

    PubMed Central

    Camorani, Simona; Crescenzi, Elvira; Colecchia, David; Carpentieri, Andrea; Amoresano, Angela; Fedele, Monica; Chiariello, Mario; Cerchia, Laura

    2015-01-01

    Glioblastoma Multiforme (GBM) is the most common and aggressive human brain tumor, associated with very poor survival despite surgery, radiotherapy and chemotherapy. The epidermal growth factor receptor (EGFR) and the platelet-derived growth factor receptor β (PDGFRβ) are hallmarks in GBM with driving roles in tumor progression. In approximately half of the tumors with amplified EGFR, the EGFRvIII truncated extracellular mutant is detected. EGFRvIII does not bind ligands, is highly oncogenic and its expression confers resistance to EGFR tyrosine kinase inhibitors (TKIs). It has been demonstrated that EGFRvIII-dependent cancers may escape targeted therapy by developing dependence on PDGFRβ signaling, thus providing a strong rationale for combination therapy aimed at blocking both EGFRvIII and PDGFRβ signaling. We have recently generated two nuclease resistant RNA aptamers, CL4 and Gint4.T, as high affinity ligands and inhibitors of the human wild-type EGFR (EGFRwt) and PDGFRβ, respectively. Herein, by different approaches, we demonstrate that CL4 aptamer binds to the EGFRvIII mutant even though it lacks most of the extracellular domain. As a consequence of binding, the aptamer inhibits EGFRvIII autophosphorylation and downstream signaling pathways, thus affecting migration, invasion and proliferation of EGFRvIII-expressing GBM cell lines. Further, we show that targeting EGFRvIII by CL4, as well as by EGFR-TKIs, erlotinib and gefitinib, causes upregulation of PDGFRβ. Importantly, CL4 and gefitinib cooperate with the anti-PDGFRβ Gint4.T aptamer in inhibiting cell proliferation. The proposed aptamer-based strategy could have impact on targeted molecular cancer therapies and may result in progresses against GBMs. PMID:26461476

  4. Acute stimulation of mesenchymal stem cells with cigarette smoke extract affects their migration, differentiation, and paracrine potential

    PubMed Central

    Wahl, Elizabeth A.; Schenck, Thilo L.; Machens, Hans-Günther; Egaña, J. Tomás

    2016-01-01

    Mesenchymal stem cells (MSCs) are known to play a key role in tissue regeneration, while smoking cigarettes is described to impair it. This work focuses on the effect cigarette smoke extract (CSE) has on the migration, differentiation, and paracrine potential of human adipose derived MSCs (AdMSCs). To mimic native conditions in vitro, AdMSCs were cultured in either monolayer or three-dimensional pellet cultures. While constant exposure to high concentrations of CSE had lethal effects on AdMSCs, lower concentrations of CSE impaired cell migration when compared to control conditions. The secretion of key interleukins was downregulated when CSE was exposed to the cells at low concentrations. Moreover, in this work AdMSCs were exposed to CSE while simultaneously being induced to differentiate into adipocytes, osteoblasts, and chondrocytes to determine the effect of CSE on the cells potential to differentiate. While adipogenic differentiation showed no significant variation, AdMSCs exposed to osteogenic and chondrogenic supplements showed both early and late genetic level variation when acutely exposed to low concentrations of CSE. Our results indicate that even a small amount of cigarette smoke can have detrimental effects on the regenerative potential of MSCs. PMID:26976359

  5. Differential Expression of CX3CL1 in Hepatitis B Virus-Replicating Hepatoma Cells Can Affect the Migration Activity of CX3CR1+ Immune Cells

    PubMed Central

    Kimura, Osamu; Tanaka, Yasuhito; Ninomiya, Masashi; Iwata, Tomoaki; Kogure, Takayuki; Inoue, Jun; Sugiyama, Masaya; Morosawa, Tatsuki; Fujisaka, Yasuyuki; Shimosegawa, Tooru

    2015-01-01

    ABSTRACT In addition to stellate cells and immune cells, inflamed hepatocytes and hepatoma cells express various kinds of chemokines that attract various kinds of immune cells. Previously, we reported that hepatitis B virus (HBV) replication can induce physiological stress. The aim of this study was to analyze the effect of chemokines produced by HBV-infected hepatocytes and hepatoma cells. A real-time PCR array targeting genes related to chemokines and enzyme-linked immunosorbent assay (ELISA) were carried out to detect the specific chemokines produced by Huh7 cells and HepG2 cells infected with various HBV genotypes. A migration assay, flow cytometry analysis, and immunohistochemistry were carried out to analyze the candidate immune cells that can affect the immunopathogenesis of HBV infection. The expressions of CX3CL1 mRNA and protein were significantly different among HBV genotypes A, B, and C and control cells (mock) (P < 0.05). CD56+ NK cells and CD8+ T cells migrated to the hepatoma cells with HBV replication. Moreover, the migration activity of both immune cells was partially cancelled after the treatment of CX3CL1 neutralizing antibody. The expression level of NKG2D on CX3CR1+ NK cells in HCC with HBV infection was significantly lower than that in hepatocellular carcinoma (HCC) with HCV infection and chronic hepatitis B and C patients (P < 0.05). On the other hand, the frequency of PD-1high CX3CR1+ CD8+ T cells in HCC with HBV infection was significantly higher than that in HCC with HCV infection and chronic hepatitis B and C (P < 0.05). The expression of CX3CL1 in HBV-replicating hepatocytes and hepatoma cells could contribute to the immunopathogenesis of HBV infection. IMPORTANCE The progressions of the disease are significantly different among HBV genotypes. However, it has not been clear that how different HBV genotypes could induce different inflammatory responses. Here, we first report that the levels of expression of CX3CL1 mRNA and protein were

  6. Entropy measures of collective cell migration

    NASA Astrophysics Data System (ADS)

    Whitby, Ariadne; Parrinello, Simona; Faisal, Aldo

    2015-03-01

    Collective cell migration is a critical process during tissue formation and repair. To this end there is a need to develop tools to quantitatively measure the dynamics of collective cell migration obtained from microscopy data. Drawing on statistical physics we use entropy of velocity fields derived from dense optic flow to quantitatively measure collective migration. Using peripheral nerve repair after injury as experimental system, we study how Schwann cells, guided by fibroblasts, migrate in cord-like structures across the cut, paving a highway for neurons. This process of emergence of organised behaviour is key for successful repair, yet the emergence of leader cells and transition from a random to ordered state is not understood. We find fibroblasts induce correlated directionality in migrating Schwann cells as measured by a decrease in the entropy of motion vector. We show our method is robust with respect to image resolution in time and space, giving a principled assessment of how various molecular mechanisms affect macroscopic features of collective cell migration. Finally, the generality of our method allows us to process both simulated cell movement and microscopic data, enabling principled fitting and comparison of in silico to in vitro. ICCS, Imperial College London & MRC Clinical Sciences Centre.

  7. Cell migration in the postnatal subventricular zone.

    PubMed

    Menezes, J R L; Marins, M; Alves, J A J; Froes, M M; Hedin-Pereira, C

    2002-12-01

    New neurons are constantly added to the olfactory bulb of rodents from birth to adulthood. This accretion is not only dependent on sustained neurogenesis, but also on the migration of neuroblasts and immature neurons from the cortical and striatal subventricular zone (SVZ) to the olfactory bulb. Migration along this long tangential pathway, known as the rostral migratory stream (RMS), is in many ways opposite to the classical radial migration of immature neurons: it is faster, spans a longer distance, does not require radial glial guidance, and is not limited to postmitotic neurons. In recent years many molecules have been found to be expressed specifically in this pathway and to directly affect this migration. Soluble factors with inhibitory, attractive and inductive roles in migration have been described, as well as molecules mediating cell-to-cell and cell-substrate interactions. However, it is still unclear how the various molecules and cells interact to account for the special migratory behavior in the RMS. Here we will propose some candidate mechanisms for roles in initiating and stopping SVZ/RMS migration.

  8. A Discrete Cell Migration Model

    SciTech Connect

    Nutaro, James J; Kruse, Kara L; Ward, Richard C; O'Quinn, Elizabeth; Woerner, Matthew M; Beckerman, Barbara G

    2007-01-01

    Migration of vascular smooth muscle cells is a fundamental process in the development of intimal hyperplasia, a precursor to development of cardiovascular disease and a potential response to injury of an arterial wall. Boyden chamber experiments are used to quantify the motion of cell populations in response to a chemoattractant gradient (i.e., cell chemotaxis). We are developing a mathematical model of cell migration within the Boyden chamber, while simultaneously conducting experiments to obtain parameter values for the migration process. In the future, the model and parameters will be used as building blocks for a detailed model of the process that causes intimal hyperplasia. The cell migration model presented in this paper is based on the notion of a cell as a moving sensor that responds to an evolving chemoattractant gradient. We compare the results of our three-dimensional hybrid model with results from a one-dimensional continuum model. Some preliminary experimental data that is being used to refine the model is also presented.

  9. Zebrafish germ cells: motility and guided migration.

    PubMed

    Paksa, Azadeh; Raz, Erez

    2015-10-01

    In the course of embryonic development, the process of cell migration is critical for establishment of the embryonic body plan, for morphogenesis and for organ function. Investigating the molecular mechanisms underlying cell migration is thus crucial for understanding developmental processes and clinical conditions resulting from abnormal cell migration such as cancer metastasis. The long-range migration of primordial germ cells toward the region at which the gonad develops occurs in embryos of various species and thus constitutes a useful in vivo model for single-cell migration. Recent studies employing zebrafish embryos have greatly contributed to the understanding of the mechanisms facilitating the migration of these cells en route to their target.

  10. Endothelial cells enhance migration of meniscus cells

    PubMed Central

    Yuan, Xiaoning; Eng, George M.; Arkonac, Derya E.; Chao, Pen-hsiu Grace; Vunjak-Novakovic, Gordana

    2014-01-01

    Objective To study the interactions between vascular endothelial cells and meniscal fibrochondrocytes from the inner avascular and outer vascular regions of the meniscus, and identify angiogenic factors that enhance cell migration and integrative repair. Methods Bovine meniscal fibrochondrocytes (bMFCs) from the inner and outer regions of meniscus were cultured for seven days with and without human umbilical vein endothelial cells (HUVECs) in a micropatterned three-dimensional hydrogel system for cell migration. Angiogenic factors secreted by HUVECs were probed for their role in paracrine mechanisms governing bMFC migration, and applied to a full-thickness defect model of meniscal repair in explants from the inner and outer regions over four weeks. Results Endothelial cells enhanced migration of inner and outer bMFCs in the micropatterned system via endothelin-1 (ET-1) signaling. Supplementation of ET-1 significantly enhanced integration strength of full-thickness defects in inner and outer explants, and cell migration at the macro-scale, compared to controls without ET-1 treatment. Conclusion We report for the first time that bMFCs from both the avascular and vascular regions respond to the presence of endothelial cells with increased migration. Paracrine signaling by endothelial cells regulates the bMFCs differentially by region, but we identify ET-1 as an angiogenic factor that stimulates migration of inner and outer cells at the micro-scale, and integrative repair of inner and outer explants at the macro-scale. These findings reveal the regional interactions between vasculature and MFCs, and suggest ET-1 as a potential new treatment modality for avascular meniscal injuries, in order to prevent the development of osteoarthritis. PMID:25307081

  11. Texture sensing of cytoskeletal dynamics in cell migration

    NASA Astrophysics Data System (ADS)

    Das, Satarupa; Lee, Rachel; Hourwitz, Matthew J.; Sun, Xiaoyu; Parent, Carole; Fourkas, John T.; Losert, Wolfgang

    Migrating cells can be directed towards a target by gradients in properties such as chemical concentration or mechanical properties of the surrounding microenvironment. In previous studies we have shown that micro/nanotopographical features on scales comparable to those of natural collagen fibers can guide fast migrating amoeboid cells by aligning actin polymerization waves to such nanostructures. We find that actin microfilaments and microtubules are aligned along the nanoridge topographies, modulating overall cell polarity and directional migration in epithelial cells. This work shows that topographic features on a biologically relevant length scale can modulate migration outcomes by affecting the texture sensing property of the cytoskeleton.

  12. Flight mode affects allometry of migration range in birds.

    PubMed

    Watanabe, Yuuki Y

    2016-08-01

    Billions of birds migrate to exploit seasonally available resources. The ranges of migration vary greatly among species, but the underlying mechanisms are poorly understood. I hypothesise that flight mode (flapping or soaring) and body mass affect migration range through their influence on flight energetics. Here, I compiled the tracks of migratory birds (196 species, weighing 12-10 350 g) recorded by electronic tags in the last few decades. In flapping birds, migration ranges decreased with body mass, as predicted from rapidly increasing flight cost with increasing body mass. The species with higher aspect ratio and lower wing loading had larger migration ranges. In soaring birds, migration ranges were mass-independent and larger than those of flapping birds, reflecting their low flight costs irrespective of body mass. This study demonstrates that many animal-tracking studies are now available to explore the general patterns and the underlying mechanisms of animal migration.

  13. Alignment of cell division axes in directed epithelial cell migration

    NASA Astrophysics Data System (ADS)

    Marel, Anna-Kristina; Podewitz, Nils; Zorn, Matthias; Oskar Rädler, Joachim; Elgeti, Jens

    2014-11-01

    Cell division is an essential dynamic event in tissue remodeling during wound healing, cancer and embryogenesis. In collective migration, tensile stresses affect cell shape and polarity, hence, the orientation of the cell division axis is expected to depend on cellular flow patterns. Here, we study the degree of orientation of cell division axes in migrating and resting epithelial cell sheets. We use microstructured channels to create a defined scenario of directed cell invasion and compare this situation to resting but proliferating cell monolayers. In experiments, we find a strong alignment of the axis due to directed flow while resting sheets show very weak global order, but local flow gradients still correlate strongly with the cell division axis. We compare experimental results with a previously published mesoscopic particle based simulation model. Most of the observed effects are reproduced by the simulations.

  14. Characterization of Collective Cell Migration Dynamics

    NASA Astrophysics Data System (ADS)

    Lee, Rachel; Yue, Haicen; Rappel, Wouter-Jan; Losert, Wolfgang

    2015-03-01

    During cancer progression, tumor cells invade the surrounding tissue and migrate throughout the body, forming clinically dangerous secondary tumors. This metastatic process begins when cells leave the primary tumor, either as individual cells or collectively migrating groups. Here we present data on the migration dynamics of epithelial sheets composed of many cells. Using quantitative image analysis techniques, we are able to extract motion information from time-lapse images of cell lines with varying malignancy. Adapting metrics originally used to study fluid flows we are able to characterize the migration dynamics of these cell lines. By describing the migration dynamics in great detail, we are able to make a clear comparison of our results to a simulation of collective cell migration. Specifically, we explore whether leader cells are required to describe our expanding sheets of cells and whether the answer depends on individual cell activity.

  15. Schwann cells promote endothelial cell migration

    PubMed Central

    Ramos, Tiago; Ahmed, Maqsood; Wieringa, Paul; Moroni, Lorenzo

    2015-01-01

    Directed cell migration is a crucial orchestrated process in embryonic development, wound healing, and immune response. The underlying substrate can provide physical and/or chemical cues that promote directed cell migration. Here, using electrospinning we developed substrates of aligned poly(lactic-co-glycolic acid) nanofibres to study the influence of glial cells on endothelial cells (ECs) in a 3-dimensional (3D) co-culture model. ECs build blood vessels and regulate their plasticity in coordination with neurons. Likewise, neurons construct nerves and regulate their circuits in coordination with ECs. In our model, the neuro-vascular cross-talk was assessed using a direct co-culture model of human umbilical vein endothelial cells (HUVECs) and rat Schwann cells (rSCs). The effect of rSCs on ECs behavior was demonstrated by earlier and higher velocity values and genetic expression profiles different of those of HUVECs when seeded alone. We observed 2 different gene expression trends in the co-culture models: (i) a later gene expression of angiogenic factors, such as interleukin-8 (IL-8) and vascular endothelial growth factor (VEGF), and (ii) an higher gene expression of genes involved in actin filaments rearrangement, such as focal adhesion kinase (FAK), Mitogen-activated protein kinase-activated protein kinase 13 (MAPKAPK13), Vinculin (VCL), and Profilin (PROF). These results suggested that the higher ECs migration is mainly due to proteins involved in the actin filaments rearrangement and in the directed cell migration rather than the effect of angiogenic factors. This co-culture model provides an approach to enlighten the neurovascular interactions, with particular focus on endothelial cell migration. PMID:26491999

  16. Factors controlling cardiac neural crest cell migration

    PubMed Central

    Hutson, Mary R

    2010-01-01

    Cardiac neural crest cells originate as part of the postotic caudal rhombencephalic neural crest stream. Ectomesenchymal cells in this stream migrate to the circumpharyngeal ridge and then into the caudal pharyngeal arches where they condense to form first a sheath and then the smooth muscle tunics of the persisting pharyngeal arch arteries. A subset of the cells continues migrating into the cardiac outflow tract where they will condense to form the aorticopulmonary septum. Cell signaling, extracellular matrix and cell-cell contacts are all critical for the initial migration, pauses, continued migration and condensation of these cells. This Review elucidates what is currently known about these factors. PMID:20890117

  17. Epithelial MUC1 promotes cell migration, reduces apoptosis and affects levels of mucosal modulators during acetylsalicylic acid (aspirin)-induced gastropathy.

    PubMed

    Banerjee, Debashish; Fernandez, Harvey Robert; Patil, Pradeep Bhatu; Premaratne, Pushpa; Quiding-Järbrink, Marianne; Lindén, Sara Katarina

    2015-02-01

    MUC1 is a transmembrane mucin highly expressed in the stomach. Although extensive research has uncovered many of its roles in cancer, knowledge about the functions of MUC1 in normal tissues is limited. In the present study, we showed that acetylsalicylic acid (ASA; aspirin) up-regulated MUC1/Muc1 expression in the gastric mucosa of humans and wild-type (WT) mice. ASA induced mucosal injury in all mice to a similar extent; however, WT animals and those chimaeras with Muc1 on the epithelia recovered faster than Muc1-knockout (KO) mice and chimaeras carrying Muc1 on haemopoietic but not epithelial cells. MUC1 enhanced proliferation and migration of the human gastric cell line MKN-7 and increased resistance to apoptosis. The repeated treatment regime used caused a reduction in cyclo-oxygenase-1 (Cox-1) expression, though WT animals returned faster towards pre-treatment levels and had increased Cox-2 and vascular endothelial growth factor levels during recovery. Thus we found that epithelial Muc1 is more important for the healing process than haemopoietic Muc1 and Muc1/MUC1 facilitates wound healing by enhancing cell migration and proliferation, protecting against apoptosis and mediating expression of mucosal modulators. Thus MUC1 plays essential roles during wound healing and development of treatment modalities targeting enhanced expression of MUC1 may be beneficial to treat mucosal wounds.

  18. Transplantation stimulates interstitial cell migration in hydra

    SciTech Connect

    Fujisawa, T.; David, C.N.; Bosch, T.C. )

    1990-04-01

    Migration of interstitial cells and nerve cell precursors was analyzed in Hydra magnipapillata and Hydra vulgaris (formerly Hydra attenuata). Axial grafts were made between ({sup 3}H)thymidine-labeled donor and unlabeled host tissue. Migration of labeled cells into the unlabeled half was followed for 4 days. The results indicate that the rate of migration was initially high and then slowed on Days 2-4. Regrafting fresh donor tissue on Days 2-4 maintained high levels of migration. Thus, migration appears to be stimulated by the grafting procedure itself.

  19. Nanotopography guides and directs cell migration in amoeboid and epithelial cells

    NASA Astrophysics Data System (ADS)

    Lee, Rachel; Das, Satarupa; Hourwitz, Matthew; Sun, Xiaoyu; Parent, Carole; Fourkas, John; Losert, Wolfgang

    Cell migration plays a critical role in development, angiogenesis, immune response, wound healing, and cancer metastasis. In many cases, cells also move in the context of a matrix of collagen fibers, and the alignment of these fibers can both affect the migration phenotype and guide cells. Here we show that both fast and slow migrating cells - amoeboid HL-60 and epithelial MCF10A - are affected in similar ways by micro/nanostructures with dimensions similar to those of collagen fibers. Cell alignment enhances the efficiency of migration by increasing directional persistence.

  20. Regulation of C6 glioma cell migration by thymol

    PubMed Central

    LEE, KANG PA; KIM, JAI-EUN; PARK, WON-HWAN; HONG, HEEOK

    2016-01-01

    Tumor cell motility exhibits a crucial role in tumor development. Therefore, the present study aimed to investigate whether thymol could reduce C6 glioma cell migration. Cell viability was determined using the EZ-Cytox Cell Viability kit. The scratch wound healing and Boyden chamber assays were performed to test C6 glioma cell migration in the presence of fetal bovine serum (FBS). Additionally, the study investigated whether signaling proteins relevant to C6 glioma cell migration, i.e., extracellular signal-regulated kinases (ERK)1/2, protein kinase Cα (PKCα), matrix metallopeptidase (MMP)9 and MMP2, were affected by thymol treatment. Up to 30 µM, thymol did not alter cell viability, whereas 100 µM thymol induced the death of ~20% of the cells. Furthermore, thymol (30 µM) significantly reduced FBS-induced migration. In the FBS-stimulated C6 glioma cells, thymol (30 µM) suppressed PKCα and ERK1/2 phosphorylation. MMP9 and MMP2 production was also significantly reduced by treatment with 30 µM thymol in the C6 glioma cells. Taken together, these results indicate that thymol attenuates C6 glioma cell migration. Additionally, the study suggests that the effect of thymol on the FBS-induced migration of C6 glioma cells affects PKCα and ERK1/2 signaling, and suppresses MMP9 and MMP2 production. PMID:27073528

  1. Cerebellar granule cell migration and the effects of alcohol.

    PubMed

    Jiang, Yulan; Kumada, Tatsuro; Cameron, D Bryant; Komuro, Hitoshi

    2008-01-01

    In the developing brain the majority of neurons migrate from their birthplace to their final destination. This active movement is essential for the formation of cortical layers and nuclei. The impairment of migration does not affect the viability of neurons but often results in abnormal differentiation. The proper migration of neurons requires the orchestrated activities of multiple cellular and molecular events, such as pathway selection, the activation of specific receptors and channels, and the assembly and disassembly of cytoskeletal components. The migration of neurons is very vulnerable to exposure to environmental toxins, such as alcohol. In this article, we will focus on recent developments in the migration of cerebellar granule cells. First, we will describe when, where and how granule cells migrate through different cortical layers to reach their final destination. Second, we will present how internal programs control the sequential changes in granule cell migration. Third, we will review the roles of external guidance cues and transmembrane signals in granule cell migration. Finally, we will reveal mechanisms by which alcohol exposure impairs granule cell migration. PMID:18075250

  2. Rho GTPase signalling in cell migration

    PubMed Central

    Ridley, Anne J

    2015-01-01

    Cells migrate in multiple different ways depending on their environment, which includes the extracellular matrix composition, interactions with other cells, and chemical stimuli. For all types of cell migration, Rho GTPases play a central role, although the relative contribution of each Rho GTPase depends on the environment and cell type. Here, I review recent advances in our understanding of how Rho GTPases contribute to different types of migration, comparing lamellipodium-driven versus bleb-driven migration modes. I also describe how cells migrate across the endothelium. In addition to Rho, Rac and Cdc42, which are well known to regulate migration, I discuss the roles of other less-well characterized members of the Rho family. PMID:26363959

  3. Glycation of extracellular matrix proteins impairs migration of immune cells.

    PubMed

    Haucke, Elisa; Navarrete-Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-01-01

    The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells. PMID:24635174

  4. Glycation of extracellular matrix proteins impairs migration of immune cells.

    PubMed

    Haucke, Elisa; Navarrete-Santos, Alexander; Simm, Andreas; Silber, Rolf-Edgar; Hofmann, Britt

    2014-01-01

    The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells.

  5. Multiscale Cues Drive Collective Cell Migration

    NASA Astrophysics Data System (ADS)

    Nam, Ki-Hwan; Kim, Peter; Wood, David K.; Kwon, Sunghoon; Provenzano, Paolo P.; Kim, Deok-Ho

    2016-07-01

    To investigate complex biophysical relationships driving directed cell migration, we developed a biomimetic platform that allows perturbation of microscale geometric constraints with concomitant nanoscale contact guidance architectures. This permits us to elucidate the influence, and parse out the relative contribution, of multiscale features, and define how these physical inputs are jointly processed with oncogenic signaling. We demonstrate that collective cell migration is profoundly enhanced by the addition of contract guidance cues when not otherwise constrained. However, while nanoscale cues promoted migration in all cases, microscale directed migration cues are dominant as the geometric constraint narrows, a behavior that is well explained by stochastic diffusion anisotropy modeling. Further, oncogene activation (i.e. mutant PIK3CA) resulted in profoundly increased migration where extracellular multiscale directed migration cues and intrinsic signaling synergistically conspire to greatly outperform normal cells or any extracellular guidance cues in isolation.

  6. Multiscale Cues Drive Collective Cell Migration

    PubMed Central

    Nam, Ki-Hwan; Kim, Peter; Wood, David K.; Kwon, Sunghoon; Provenzano, Paolo P.; Kim, Deok-Ho

    2016-01-01

    To investigate complex biophysical relationships driving directed cell migration, we developed a biomimetic platform that allows perturbation of microscale geometric constraints with concomitant nanoscale contact guidance architectures. This permits us to elucidate the influence, and parse out the relative contribution, of multiscale features, and define how these physical inputs are jointly processed with oncogenic signaling. We demonstrate that collective cell migration is profoundly enhanced by the addition of contract guidance cues when not otherwise constrained. However, while nanoscale cues promoted migration in all cases, microscale directed migration cues are dominant as the geometric constraint narrows, a behavior that is well explained by stochastic diffusion anisotropy modeling. Further, oncogene activation (i.e. mutant PIK3CA) resulted in profoundly increased migration where extracellular multiscale directed migration cues and intrinsic signaling synergistically conspire to greatly outperform normal cells or any extracellular guidance cues in isolation. PMID:27460294

  7. Cyclin D1 functions in cell migration.

    PubMed

    Li, Zhiping; Wang, Chenguang; Prendergast, George C; Pestell, Richard G

    2006-11-01

    Cell migration is essential for developmental morphogenesis, tissue repair, and tumor metastasis. A recent study reveals that cyclin D1 acts to promote cell migration by inhibiting Rho/ROCK signaling and expression of thrombospondin-1 (TSP-1), an extracellular matrix protein that regulates cell migration in many settings including cancer. Given the frequent overexpression of cyclin D1 in cancer cells, due to its upregulation by Ras, Rho, Src, and other genes that drive malignant development, the new findings suggest that cyclin D1 may have a central role in mediating invasion and metastasis of cancer cells by controlling Rho/ROCK signaling and matrix deposition of TSP-1.

  8. Centrosome Positioning in 1D Cell Migration

    NASA Astrophysics Data System (ADS)

    Adlerz, Katrina; Aranda-Espinoza, Helim

    During cell migration, the positioning of the centrosome and nucleus define a cell's polarity. For a cell migrating on a two-dimensional substrate the centrosome is positioned in front of the nucleus. Under one-dimensional confinement, however, the centrosome is positioned behind the nucleus in 60% of cells. It is known that the centrosome is positioned by CDC42 and dynein for cells moving on a 2D substrate in a wound-healing assay. It is currently unknown, however, if this is also true for cells moving under 1D confinement, where the centrosome position is often reversed. Therefore, centrosome positioning was studied in cells migrating under 1D confinement, which mimics cells migrating through 3D matrices. 3 to 5 μm fibronectin lines were stamped onto a glass substrate and cells with fluorescently labeled nuclei and centrosomes migrated on the lines. Our results show that when a cell changes directions the centrosome position is maintained. That is, when the centrosome is between the nucleus and the cell's trailing edge and the cell changes direction, the centrosome will be translocated across the nucleus to the back of the cell again. A dynein inhibitor did have an influence on centrosome positioning in 1D migration and change of directions.

  9. Deoxynivalenol affects the composition of the basement membrane proteins and influences en route the migration of CD16(+) cells into the intestinal epithelium.

    PubMed

    Nossol, Constanze; Diesing, A K; Kahlert, S; Kersten, S; Kluess, J; Ponsuksili, S; Hartig, R; Wimmers, K; Dänicke, S; Rothkötter, H J

    2013-11-01

    The numerous pores in the basement membrane (BM) of the intestinal villi are essential for the communication of enterocytes with cells in the lamina propria, an important mechanism for the induction of intestinal immune responses. The intestinal epithelial barrier is affected by the mycotoxin deoxynivalenol (DON) from both the apical (luminal) and basolateral (serosal) side. The pig is the most susceptible species to the anorectic and immune-modulating effects of DON, which is most prevalent in crops. We analysed in pigs the effect of DON-contaminated feed on the composition and perforation of the BM and the presence of CD16(+) cells or their dendrites in the epithelium. In addition to in vivo experiments, in vitro studies were carried out. Using microarray analyses, the effects of DON on IPEC-J2 cells were studied with the focus on the BM. Our in vivo results showed in the control pigs: (1) a significant increased pore number (p ≤ 0.001) in the jejunum in comparison to ileum, (2) no difference in the pore size, and (3) comparable frequency of intraepithelial CD16(+) cells/dendrites in the jejunum and ileum. There was a marked trend that DON feeding increases: (1) the pore number in jejunum, and (2) the number of CD16(+) cells/dendrites in the epithelium (Tukey-Kramer; p = 0.055 and p = 0.067, respectively). The in vivo results were extended with microarray analyses of epithelial cell (IPEC-J2 cells). The down-regulation of genes like syndecan, fibulin 6 and BM-40 was observed. These proteins are important factors in the BM composition and in formation of pores. Our results provide evidence that already low basolateral concentrations of DON (50 ng/mL) influence the production of the BM protein laminin by epithelial cells. Thus, DON affects the composition of the BM.

  10. A PTK7/Ror2 Co-Receptor Complex Affects Xenopus Neural Crest Migration

    PubMed Central

    Berger, Hanna; Rollwitz, Erik; Borchers, Annette

    2015-01-01

    Neural crest cells are a highly migratory pluripotent cell population that generates a wide array of different cell types and failure in their migration can result in severe birth defects and malformation syndromes. Neural crest migration is controlled by various means including chemotaxis, repellent guidance cues and cell-cell interaction. Non-canonical Wnt PCP (planar cell polarity) signaling has previously been shown to control cell-contact mediated neural crest cell guidance. PTK7 (protein tyrosine kinase 7) is a transmembrane pseudokinase and a known regulator of Wnt/PCP signaling, which is expressed in Xenopus neural crest cells and required for their migration. PTK7 functions as a Wnt co-receptor; however, it remains unclear by which means PTK7 affects neural crest migration. Expressing fluorescently labeled proteins in Xenopus neural crest cells we find that PTK7 co-localizes with the Ror2 Wnt-receptor. Further, co-immunoprecipitation experiments demonstrate that PTK7 interacts with Ror2. The PTK7/Ror2 interaction is likely relevant for neural crest migration, because Ror2 expression can rescue the PTK7 loss of function migration defect. Live cell imaging of explanted neural crest cells shows that PTK7 loss of function affects the formation of cell protrusions as well as cell motility. Co-expression of Ror2 can rescue these defects. In vivo analysis demonstrates that a kinase dead Ror2 mutant cannot rescue PTK7 loss of function. Thus, our data suggest that Ror2 can substitute for PTK7 and that the signaling function of its kinase domain is required for this effect. PMID:26680417

  11. Hedgehog does not guide migrating Drosophila germ cells

    PubMed Central

    Renault, Andrew D.; Ricardo, Sara; Kunwar, Prabhat S.; Santos, Ana; Starz-Gaiano, Michelle; Stein, Jennifer; Lehmann, Ruth

    2009-01-01

    In many species, the germ cells, precursors of sperm and egg, migrate during embryogenesis. The signals that regulate this migration are thus essential for fertility. In flies, lipid signals have been shown to affect germ cell guidance. In particular, the synthesis of geranylgeranyl pyrophosphate through the 3-hydroxy-3-methyl-glutaryl coenzyme A reductase (Hmgcr) pathway is critical for attracting germ cells to their target tissue. In a genetic analysis of signaling pathways known to affect cell migration of other migratory cells, we failed to find a role for the Hedgehog (Hh) pathway in germ cell migration. However, previous reports had implicated Hh as a germ cell attractant in flies and suggested that Hh signaling is enhanced through the action of the Hmgcr pathway. We therefore repeated several critical experiments and carried out further experiments to test specifically whether Hh is a germ cell attractant in flies. In contrast to previously reported findings and consistent with findings in zebrafish our data do not support the notion that Hh has a direct role in the guidance of migrating germ cells in flies. PMID:19389345

  12. miR-186 and 326 predict the prognosis of pancreatic ductal adenocarcinoma and affect the proliferation and migration of cancer cells.

    PubMed

    Zhang, Zheng-liang; Bai, Zheng-hai; Wang, Xiao-bo; Bai, Ling; Miao, Fei; Pei, Hong-hong

    2015-01-01

    MicroRNAs can function as key tumor suppressors or oncogenes and act as biomarkers for cancer diagnosis or prognosis. Although high-throughput assays have revealed many miRNA biomarkers for pancreatic ductal adenocarcinoma (PDAC), only a few have been validated in independent populations or investigated for functional significance in PDAC pathogenesis. In this study, we correlated the expression of 36 potentially prognostic miRNAs within PDAC tissue with clinico-pathological features and survival in 151 Chinese patients. We then analyzed the functional roles and target genes of two miRNAs in PDAC development. We found that high expression of miR-186 and miR-326 predict poor and improved survival, respectively. miR-186 was over-expressed in PDAC patients compared with controls, especially in patients with large tumors (>2 cm), lymph node metastasis, or short-term survival (< 24 months). In contrast, miR-326 was down-regulated in patients compared with controls and displayed relatively increased expression in the patients with long-term survival or without venous invasion. Functional experiments revealed that PDAC cell proliferation and migration was decreased following inhibition and enhanced following over-expression of miR-186. In contrast, it was enhanced following inhibition and decreased after over-expression of miR-326. A luciferase assay indicated that miR-186 can bind directly to the 3'-UTR of NR5A2 to repress gene expression. These findings suggest that miR-186 over-expression contributes to the invasive potential of PDAC, likely via suppression of NR5A2, thereby leading to a poor prognosis; high miR-326 expression prolongs survival likely via the decreasing invasive potential of PDAC cells. These two miRNAs can be used as markers for clinical diagnosis and prognosis, and they represent therapeutic targets for PDAC.

  13. Migration of Airway Smooth Muscle Cells

    PubMed Central

    Gerthoffer, William T.

    2008-01-01

    Migration of smooth muscle cells is a process fundamental to development of hollow organs, including blood vessels and the airways. Migration is also thought to be part of the response to tissue injury. It has also been suggested to contribute to airways remodeling triggered by chronic inflammation. In both nonmuscle and smooth muscle cells numerous external signaling molecules and internal signal transduction pathways contribute to cell migration. The review includes evidence for the functional significance of airway smooth muscle migration, a summary of promigratory and antimigratory agents, and summaries of important signaling pathways mediating migration. Important signaling pathways and effector proteins described include small G proteins, phosphatidylinositol 3-kinases (PI3-K), Rho activated protein kinase (ROCK), p21-activated protein kinases (PAK), Src family tyrosine kinases, and mitogen-activated protein kinases (MAPK). These signaling modules control multiple critical effector proteins including actin nucleating, capping and severing proteins, myosin motors, and proteins that remodel microtubules. Actin filament remodeling, focal contact remodeling and propulsive force of molecular motors are all coordinated to move cells along gradients of chemical cues, matrix adhesiveness, or matrix stiffness. Airway smooth muscle cell migration can be modulated in vitro by drugs commonly used in pulmonary medicine including β-adrenergic agonists and corticosteroids. Future studies of airway smooth muscle cell migration may uncover novel targets for drugs aimed at modifying airway remodeling. PMID:18094091

  14. Cyclin D1/cyclin dependent kinase 4 interacts with filamin A and affects the migration and invasion potential of breast cancer cells

    PubMed Central

    Zhong, Zhijiu; Yeow, Wen-Shuz; Zou, Chunhua; Wassell, Richard; Wang, Chenguang; Pestell, Richard G.; Quong, Judy N.; Quong, Andrew A.

    2010-01-01

    Cyclin D1 belongs to the family of proteins that regulates progression through the G1-S phase of the cell cycle through binding to cyclin dependent kinase 4 to phosphorylate the retinoblastoma protein and release E2F transcription factors for progression through cell cycle. Several cancers, including breast, colon and prostate over-express the cyclin D1 gene. However, the correlation between cyclin D1 over-expression with E2F target gene regulation or cyclin dependent kinase-dependent cyclin D1 activity with tumor development have not been identified. This suggests that the role of cyclin D1 in oncogenesis may be independent of its function as a cell cycle regulator. One such function is the role of cyclin D1 in cell adhesion and motility. Filamin A, a member of the actin-binding filamin protein family, regulates signaling events involved in cell motility and invasion. Filamin A has also been associated with a variety of cancers including lung, prostate, melanoma, human bladder cancer, and neuroblastoma. We hypothesized that elevated cyclin D1 facilitates motility in the invasive MDA-MB-231 breast cancer cell line. We show that MDA-MB-231 motility is affected by disturbing cyclin D1 levels or cyclin D1-cdk4/6 kinase activity. Using mass spectrometry, we found that cyclin D1 and Filamin A co-immunoprecipitate and that lower levels of cyclin D1 are associated with decreased phosphorylation of FLNa at serine 2152 and 1459. We also identify many proteins related to cytoskeletal function, biomolecular synthesis, organelle biogenesis, and calcium regulation whose levels of expression change concomitant with decreased cell motility induced by decreased cyclin D1 and cyclin D1-cdk4/6 activity. PMID:20179208

  15. Modelling Rho GTPase biochemistry to predict collective cell migration

    NASA Astrophysics Data System (ADS)

    Merchant, Brian; Feng, James

    The collective migration of cells, due to individual cell polarization and intercellular contact inhibition of locomotion, features prominently in embryogenesis and metastatic cancers. Existing methods for modelling collectively migrating cells tend to rely either on highly abstracted agent-based models, or on continuum approximations of the group. Both of these frameworks represent intercellular interactions such as contact inhibition of locomotion as hard-coded rules defining model cells. In contrast, we present a vertex-dynamics framework which predicts polarization and contact inhibition of locomotion naturally from an underlying model of Rho GTPase biochemistry and cortical mechanics. We simulate the interaction between many such model cells, and study how modulating Rho GTPases affects migratory characteristics of the group, in the context of long-distance collective migration of neural crest cells during embryogenesis.

  16. Emergence of oligarchy in collective cell migration

    NASA Astrophysics Data System (ADS)

    Schumacher, Linus; Maini, Philip; Baker, Ruth

    Identifying the principles of collective cell migration has the potential to help prevent birth defects, improve regenerative therapies and develop model systems for cancer metastasis. In collaboration with experimental biologists, we use computational simulations of a hybrid model, comprising individual-based stochastic cell movement coupled to a reaction-diffusion equation for a chemoattractant, to explore the role of cell specialisation in the guidance of collective cell migration. In the neural crest, an important migratory cell population in vertebrate embryo development, we present evidence that just a few cells are guiding group migration in a cell-induced chemoattractant gradient that determines the switch between ``leader'' and ``follower'' behaviour in individual cells. This leads us to more generally consider under what conditions cell specialisation might become advantageous for collective migration. Alternatively, individual cell responses to locally different microenvironmental conditions could create the (artefactual) appearance of heterogeneity in a population of otherwise identical cellular agents. We explore these questions using a self-propelled particle model as a minimal description for collective cell migration in two and three dimensions.

  17. Cell density determines epithelial migration in culture.

    PubMed Central

    Rosen, P; Misfeldt, D S

    1980-01-01

    The dog kidney epithelial cell line (MDCK) has been shown to exhibit a density-correlated inhibition of growth at approxmately 6.6 X 10(5) cells per cm2. When a confluent monolayer at its maximal density was wounded by removal of a wide swath of cells, migration of the cell sheet into the denuded area occurred. Precise measurements of the rate of migration for 5 day showed that the cells accelerated at a uniform rate of 0.24 micrometer . hr-2 and, by extrapolation, possessed an apparent initial velocity of 2.8 micrometer . hr-1 at the time of wounding. The apparent initial velocity was considered to be the result of a brief (< 10 hr) and rapid acceleration dependent on cell density. To verify this, wounds were made at different densities below the maximum. In these experiments, the cells did not migrate until a "threshold" density of 2.0 X 10(5) cells per cm2 was reached regardless of the density at the time of wounding. At the threshold density, the cell sheet began to accelerate at the previously measured rate (0.24 micrometer . hr-2). Any increase in density by cell division was balanced by cell migration, so that the same threshold density was maintained by the migrating cells. Each migrating cell sustained the movement of the cell sheet at a constant rate of acceleration. It is proposed that an acceleration is, in general, characteristic of the vectorial movement of an epithelial cell sheet. Images PMID:6933523

  18. Chemistry and biology of the compounds that modulate cell migration.

    PubMed

    Tashiro, Etsu; Imoto, Masaya

    2016-03-01

    Cell migration is a fundamental step for embryonic development, wound repair, immune responses, and tumor cell invasion and metastasis. Extensive studies have attempted to reveal the molecular mechanisms behind cell migration; however, they remain largely unclear. Bioactive compounds that modulate cell migration show promise as not only extremely powerful tools for studying the mechanisms behind cell migration but also as drug seeds for chemotherapy against tumor metastasis. Therefore, we have screened cell migration inhibitors and analyzed their mechanisms for the inhibition of cell migration. In this mini-review, we introduce our chemical and biological studies of three cell migration inhibitors: moverastin, UTKO1, and BU-4664L.

  19. Visualizing T Cell Migration in situ

    PubMed Central

    Benechet, Alexandre P.; Menon, Manisha; Khanna, Kamal M.

    2014-01-01

    Mounting a protective immune response is critically dependent on the orchestrated movement of cells within lymphoid tissues. The structure of secondary lymphoid organs regulates immune responses by promoting optimal cell–cell and cell–extracellular matrix interactions. Naïve T cells are initially activated by antigen presenting cells in secondary lymphoid organs. Following priming, effector T cells migrate to the site of infection to exert their functions. Majority of the effector cells die while a small population of antigen-specific T cells persists as memory cells in distinct anatomical locations. The persistence and location of memory cells in lymphoid and non-lymphoid tissues is critical to protect the host from re-infection. The localization of memory T cells is carefully regulated by several factors including the highly organized secondary lymphoid structure, the cellular expression of chemokine receptors and compartmentalized secretion of their cognate ligands. This balance between the anatomy and the ordered expression of cell surface and soluble proteins regulates the subtle choreography of T cell migration. In recent years, our understanding of cellular dynamics of T cells has been advanced by the development of new imaging techniques allowing in situ visualization of T cell responses. Here, we review the past and more recent studies that have utilized sophisticated imaging technologies to investigate the migration dynamics of naïve, effector, and memory T cells. PMID:25120547

  20. Chemokine-Mediated Migration of Mesencephalic Neural Crest Cells

    PubMed Central

    Rezzoug, Francine; Seelan, Ratnam S.; Bhattacherjee, Vasker; Greene, Robert M.; Pisano, M. Michele

    2011-01-01

    Clefts of the lip and/or palate are among the most prevalent birth defects affecting approximately 7000 newborns in the United States annually. Disruption of the developmentally programmed migration of neural crest cells (NCCs) into the orofacial region is thought to be one of the major causes of orofacial clefting. Signaling of the chemokine SDF-1 (Stromal Derived Factor-1) through its specific receptor, CXCR4, is required for the migration of many stem cell and progenitor cell populations from their respective sites of emergence to the regions where they differentiate into complex cell types, tissues and organs. In the present study, “transwell” assays of chick embryo mesencephalic (cranial) NCC migration and ex ovo whole embryo “bead implantation” assays were utilized to determine whether SDF-1/CXCR4 signaling mediates mesencephalic NCC migration. Results from this study demonstrate that attenuation of SDF-1 signaling, through the use of specific CXCR4 antagonists (AMD3100 and TN14003), disrupts the migration of mesencephalic NCCs into the orofacial region, suggesting a novel role for SDF-1/CXCR4 signaling in the directed migration of mesencephalic NCCs in the early stage embryo. PMID:22015108

  1. Primordial Germ Cell Specification and Migration

    PubMed Central

    Marlow, Florence

    2015-01-01

    Primordial germ cells are the progenitor cells that give rise to the gametes. In some animals, the germline is induced by zygotic transcription factors, whereas in others, primordial germ cell specification occurs via inheritance of maternally provided gene products known as germ plasm. Once specified, the primordial germ cells of some animals must acquire motility and migrate to the gonad in order to survive. In all animals examined, perinuclear structures called germ granules form within germ cells. This review focuses on some of the recent studies, conducted by several groups using diverse systems, from invertebrates to vertebrates, which have provided mechanistic insight into the molecular regulation of germ cell specification and migration. PMID:26918157

  2. Inhibition of REST Suppresses Proliferation and Migration in Glioblastoma Cells.

    PubMed

    Zhang, Dianbao; Li, Ying; Wang, Rui; Li, Yunna; Shi, Ping; Kan, Zhoumi; Pang, Xining

    2016-01-01

    Glioblastoma (GBM) is the most common primary brain tumor, with poor prognosis and a lack of effective therapeutic options. The aberrant expression of transcription factor REST (repressor element 1-silencing transcription factor) had been reported in different kinds of tumors. However, the function of REST and its mechanisms in GBM remain elusive. Here, REST expression was inhibited by siRNA silencing in U-87 and U-251 GBM cells. Then CCK-8 assay showed significantly decreased cell proliferation, and the inhibition of migration was verified by scratch wound healing assay and transwell assay. Using cell cycle analysis and Annexin V/PI straining assay, G1 phase cell cycle arrest was found to be a reason for the suppression of cell proliferation and migration upon REST silencing, while apoptosis was not affected by REST silencing. Further, the detection of REST-downstream genes involved in cytostasis and migration inhibition demonstrated that CCND1 and CCNE1 were reduced; CDK5R1, BBC3, EGR1, SLC25A4, PDCD7, MAPK11, MAPK12, FADD and DAXX were enhanced, among which BBC3 and DAXX were direct targets of REST, as verified by ChIP (chromatin immunoprecipitation) and Western blotting. These data suggested that REST is a master regulator that maintains GBM cells proliferation and migration, partly through regulating cell cycle by repressing downstream genes, which might represent a potential target for GBM therapy. PMID:27153061

  3. Inhibition of REST Suppresses Proliferation and Migration in Glioblastoma Cells

    PubMed Central

    Zhang, Dianbao; Li, Ying; Wang, Rui; Li, Yunna; Shi, Ping; Kan, Zhoumi; Pang, Xining

    2016-01-01

    Glioblastoma (GBM) is the most common primary brain tumor, with poor prognosis and a lack of effective therapeutic options. The aberrant expression of transcription factor REST (repressor element 1-silencing transcription factor) had been reported in different kinds of tumors. However, the function of REST and its mechanisms in GBM remain elusive. Here, REST expression was inhibited by siRNA silencing in U-87 and U-251 GBM cells. Then CCK-8 assay showed significantly decreased cell proliferation, and the inhibition of migration was verified by scratch wound healing assay and transwell assay. Using cell cycle analysis and Annexin V/PI straining assay, G1 phase cell cycle arrest was found to be a reason for the suppression of cell proliferation and migration upon REST silencing, while apoptosis was not affected by REST silencing. Further, the detection of REST-downstream genes involved in cytostasis and migration inhibition demonstrated that CCND1 and CCNE1 were reduced; CDK5R1, BBC3, EGR1, SLC25A4, PDCD7, MAPK11, MAPK12, FADD and DAXX were enhanced, among which BBC3 and DAXX were direct targets of REST, as verified by ChIP (chromatin immunoprecipitation) and Western blotting. These data suggested that REST is a master regulator that maintains GBM cells proliferation and migration, partly through regulating cell cycle by repressing downstream genes, which might represent a potential target for GBM therapy. PMID:27153061

  4. Bursts of activity in collective cell migration

    PubMed Central

    Chepizhko, Oleksandr; Giampietro, Costanza; Mastrapasqua, Eleonora; Nourazar, Mehdi; Ascagni, Miriam; Sugni, Michela; Fascio, Umberto; Leggio, Livio; Malinverno, Chiara; Scita, Giorgio; Santucci, Stéphane; Alava, Mikko J.; Zapperi, Stefano; La Porta, Caterina A. M.

    2016-01-01

    Dense monolayers of living cells display intriguing relaxation dynamics, reminiscent of soft and glassy materials close to the jamming transition, and migrate collectively when space is available, as in wound healing or in cancer invasion. Here we show that collective cell migration occurs in bursts that are similar to those recorded in the propagation of cracks, fluid fronts in porous media, and ferromagnetic domain walls. In analogy with these systems, the distribution of activity bursts displays scaling laws that are universal in different cell types and for cells moving on different substrates. The main features of the invasion dynamics are quantitatively captured by a model of interacting active particles moving in a disordered landscape. Our results illustrate that collective motion of living cells is analogous to the corresponding dynamics in driven, but inanimate, systems. PMID:27681632

  5. Networking galore: intermediate filaments and cell migration.

    PubMed

    Chung, Byung-Min; Rotty, Jeremy D; Coulombe, Pierre A

    2013-10-01

    Intermediate filaments (IFs) are assembled from a diverse group of evolutionarily conserved proteins and are specified in a tissue-dependent, cell type-dependent, and context-dependent fashion in the body. IFs are involved in multiple cellular processes that are crucial for the maintenance of cell and tissue integrity and the response and adaptation to various stresses, as conveyed by the broad array of crippling clinical disorders caused by inherited mutations in IF coding sequences. Accordingly, the expression, assembly, and organization of IFs are tightly regulated. Migration is a fitting example of a cell-based phenomenon in which IFs participate as both effectors and regulators. With a particular focus on vimentin and keratin, we here review how the contributions of IFs to the cell's mechanical properties, to cytoarchitecture and adhesion, and to regulatory pathways collectively exert a significant impact on cell migration.

  6. The effects of acoustic vibration on fibroblast cell migration.

    PubMed

    Mohammed, Taybia; Murphy, Mark F; Lilley, Francis; Burton, David R; Bezombes, Frederic

    2016-12-01

    Cells are known to interact and respond to external mechanical cues and recent work has shown that application of mechanical stimulation, delivered via acoustic vibration, can be used to control complex cell behaviours. Fibroblast cells are known to respond to physical cues generated in the extracellular matrix and it is thought that such cues are important regulators of the wound healing process. Many conditions are associated with poor wound healing, so there is need for treatments/interventions, which can help accelerate the wound healing process. The primary aim of this research was to investigate the effects of mechanical stimulation upon the migratory and morphological properties of two different fibroblast cells namely; human lung fibroblast cells (LL24) and subcutaneous areolar/adipose mouse fibroblast cells (L929). Using a speaker-based system, the effects of mechanical stimulation (0-1600Hz for 5min) on the mean cell migration distance (μm) and actin organisation was investigated. The results show that 100Hz acoustic vibration enhanced cell migration for both cell lines whereas acoustic vibration above 100Hz was found to decrease cell migration in a frequency dependent manner. Mechanical stimulation was also found to promote changes to the morphology of both cell lines, particularly the formation of lamellipodia and filopodia. Overall lamellipodia was the most prominent actin structure displayed by the lung cell (LL24), whereas filopodia was the most prominent actin feature displayed by the fibroblast derived from subcutaneous areolar/adipose tissue. Mechanical stimulation at all the frequencies used here was found not to affect cell viability. These results suggest that low-frequency acoustic vibration may be used as a tool to manipulate the mechanosensitivity of cells to promote cell migration. PMID:27612824

  7. Impact of jamming on collective cell migration

    NASA Astrophysics Data System (ADS)

    Nnetu, Kenechukwu David; Knorr, Melanie; Pawlizak, Steve; Fuhs, Thomas; Zink, Mareike; KäS, Josef A.

    2012-02-01

    Multi-cellular migration plays an important role in physiological processes such as embryogenesis, cancer metastasis and tissue repair. During migration, single cells undergo cycles of extension, adhesion and retraction resulting in morphological changes. In a confluent monolayer, there are inter-cellular interactions and crowding, however, the impact of these interactions on the dynamics and elasticity of the monolayer at the multi-cellular and single cell level is not well understood. Here we study the dynamics of a confluent epithelial monolayer by simultaneously measuring cell motion at the multi-cellular and single cell level for various cell densities and tensile elasticity. At the multi-cellular level, the system exhibited spatial kinetic transitions from isotropic to anisotropic migration on long times and the velocity of the monolayer decreased with increasing cell density. Moreover, the dynamics was spatially and temporally heterogeneous. Interestingly, the dynamics was also heterogeneous in wound-healing assays and the correlation length was fitted by compressed exponential. On the single cell scale, we observed transient caging effects with increasing cage rearrangement times as the system age due to an increase in density. Also, the density dependent elastic modulus of the monolayer scaled as a weak power law. Together, these findings suggest that caging effects at the single cell level initiates a slow and heterogeneous dynamics at the multi-cellular level which is similar to the glassy dynamics of deformable colloidal systems.

  8. Contractile forces in tumor cell migration.

    PubMed

    Mierke, Claudia Tanja; Rösel, Daniel; Fabry, Ben; Brábek, Jan

    2008-09-01

    Cancer is a deadly disease primarily because of the ability of tumor cells to spread from the primary tumor, to invade into the connective tissue, and to form metastases at distant sites. In contrast to cell migration on a planar surface where large cell tractions and contractile forces are not essential, tractions and forces are thought to be crucial for overcoming the resistance and steric hindrance of a dense three-dimensional connective tissue matrix. In this review, we describe recently developed biophysical tools, including 2-D and 3-D traction microscopy to measure contractile forces of cells. We discuss evidence indicating that tumor cell invasiveness is associated with increased contractile force generation.

  9. Endothelial Cell Morphology and Migration are Altered by Changes in Gravitational Fields

    NASA Technical Reports Server (NTRS)

    Melhado, Caroline; Sanford, Gary; Harris-Hooker, Sandra

    1997-01-01

    Endothelial cell migration is important to vascular wall regeneration following injury or stress. However, the mechanism(s) governing this response is not well understood. The microgravity environment of space may complicate the response of these cells to injury. To date, there are no reports in this area. We examined how bovine aortic (BAEC) and pulmonary (BPEC) endothelial cells respond to denudation injury under hypergravity (HGrav) and simulated microgravity (MGrav), using image analysis. In 10% FBS, the migration of confluent BAEC and BPEC into the denuded area was not affected by HGrav or MGrav. However, in low FBS (0.5%), signficantly retarded migration under MGrav, and increased migration under HGrav was found. MGrav also decreased the migration of postconfluent BPEC while HGrav showed no difference. Both MGrav and HGrav strongly decreased the migration of postconfluent BAEC. Also, both cell lines showed significant morphological changes by scanning electron microscopy. These studies indicate that endothelial cell function is affected by changes in gravity.

  10. T cell migration, search strategies and mechanisms.

    PubMed

    Krummel, Matthew F; Bartumeus, Frederic; Gérard, Audrey

    2016-03-01

    T cell migration is essential for T cell responses; it allows for the detection of cognate antigen at the surface of antigen-presenting cells and for interactions with other cells involved in the immune response. Although appearing random, growing evidence suggests that T cell motility patterns are strategic and governed by mechanisms that are optimized for both the activation stage of the cell and for environment-specific cues. In this Opinion article, we discuss how the combined effects of T cell-intrinsic and -extrinsic forces influence T cell motility patterns in the context of highly complex tissues that are filled with other cells involved in parallel motility. In particular, we examine how insights from 'search theory' can be used to describe T cell movement across an 'exploitation-exploration trade-off' in the context of activation versus effector function and lymph nodes versus peripheral tissues. PMID:26852928

  11. Tre1, a G Protein-Coupled Receptor, Directs Transepithelial Migration of Drosophila Germ Cells

    PubMed Central

    2003-01-01

    In most organisms, germ cells are formed distant from the somatic part of the gonad and thus have to migrate along and through a variety of tissues to reach the gonad. Transepithelial migration through the posterior midgut (PMG) is the first active step during Drosophila germ cell migration. Here we report the identification of a novel G protein-coupled receptor (GPCR), Tre1, that is essential for this migration step. Maternal tre1 RNA is localized to germ cells, and tre1 is required cell autonomously in germ cells. In tre1 mutant embryos, most germ cells do not exit the PMG. The few germ cells that do leave the midgut early migrate normally to the gonad, suggesting that this gene is specifically required for transepithelial migration and that mutant germ cells are still able to recognize other guidance cues. Additionally, inhibiting small Rho GTPases in germ cells affects transepithelial migration, suggesting that Tre1 signals through Rho1. We propose that Tre1 acts in a manner similar to chemokine receptors required during transepithelial migration of leukocytes, implying an evolutionarily conserved mechanism of transepithelial migration. Recently, the chemokine receptor CXCR4 was shown to direct migration in vertebrate germ cells. Thus, germ cells may more generally use GPCR signaling to navigate the embryo toward their target. PMID:14691551

  12. IL-1α Expression in Pancreatic Ductal Adenocarcinoma Affects the Tumor Cell Migration and Is Regulated by the p38MAPK Signaling Pathway

    PubMed Central

    Tjomsland, Vegard; Bojmar, Linda; Sandström, Per; Bratthäll, Charlotte; Messmer, Davorka; Spångeus, Anna; Larsson, Marie

    2013-01-01

    The interplay between the tumor cells and the surrounding stroma creates inflammation, which promotes tumor growth and spread. The inflammation is a hallmark for pancreatic adenocarcinoma (PDAC) and is to high extent driven by IL-1α. IL-1α is expressed and secreted by the tumor cells and exerting its effect on the stroma, i.e. cancer associated fibroblasts (CAF), which in turn produce massive amount of inflammatory and immune regulatory factors. IL-1 induces activation of transcription factors such as nuclear factor-κβ (NF-κβ), but also activator protein 1 (AP-1) via the small G-protein Ras. Dysregulation of Ras pathways are common in cancer as this oncogene is the most frequently mutated in many cancers. In contrast, the signaling events leading up to the expression of IL-1α by tumor cells are not well elucidated. Our aim was to examine the signaling cascade involved in the induction of IL-1α expression in PDAC. We found p38MAPK, activated by the K-Ras signaling pathway, to be involved in the expression of IL-1α by PDAC as blocking this pathway decreased both the gene and protein expression of IL-1α. Blockage of the P38MAPK signaling in PDAC also dampened the ability of the tumor cell to induce inflammation in CAFs. In addition, the IL-1α autocrine signaling regulated the migratory capacity of PDAC cells. Taken together, the blockage of signaling pathways leading to IL-1α expression and/or neutralization of IL-1α in the PDAC microenvironment should be taken into consideration as possible treatment or complement to existing treatment of this cancer. PMID:23951028

  13. Cadmium migration in aerospace nickel cadmium cells

    NASA Technical Reports Server (NTRS)

    Mcdermott, P. P.

    1976-01-01

    The effects of temperature, the nature of separator material, charge and discharge, carbonate contamination, and the mode of storage are studied with respect to the migration of active material from the negative toward the positive plate. A theoretical model is proposed which takes into account the solubility of cadmium in various concentrations of hydroxide and carbonate at different temperatures, the generation of the cadmiate ion, Cd(OH)3(-), during discharge, the migration of the cadmiate ion and particulate Cd(OH)2 due to electrophoretic effects and the movement of electrolyte in and out of the negative plate and, finally, the recrystallization of cadmiate ion in the separator as Cd(OH)2. Application of the theoretical model to observations of cadmium migration in cycled cells is also discussed.

  14. Nestin(+) cells direct inflammatory cell migration in atherosclerosis.

    PubMed

    Del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin(+) cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin(+) cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin(+) cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin(+) cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin(+) stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin(+) cells-but not in endothelial cells only- increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  15. Cell migration during heart regeneration in zebrafish.

    PubMed

    Tahara, Naoyuki; Brush, Michael; Kawakami, Yasuhiko

    2016-07-01

    Zebrafish possess the remarkable ability to regenerate injured hearts as adults, which contrasts the very limited ability in mammals. Although very limited, mammalian hearts do in fact have measurable levels of cardiomyocyte regeneration. Therefore, elucidating mechanisms of zebrafish heart regeneration would provide information of naturally occurring regeneration to potentially apply to mammalian studies, in addition to addressing this biologically interesting phenomenon in itself. Studies over the past 13 years have identified processes and mechanisms of heart regeneration in zebrafish. After heart injury, pre-existing cardiomyocytes dedifferentiate, enter the cell cycle, and repair the injured myocardium. This process requires interaction with epicardial cells, endocardial cells, and vascular endothelial cells. Epicardial cells envelope the heart, while endocardial cells make up the inner lining of the heart. They provide paracrine signals to cardiomyocytes to regenerate the injured myocardium, which is vascularized during heart regeneration. In addition, accumulating results suggest that local migration of these major cardiac cell types have roles in heart regeneration. In this review, we summarize the characteristics of various heart injury methods used in the research community and regeneration of the major cardiac cell types. Then, we discuss local migration of these cardiac cell types and immune cells during heart regeneration. Developmental Dynamics 245:774-787, 2016. © 2016 Wiley Periodicals, Inc. PMID:27085002

  16. Nestin+ cells direct inflammatory cell migration in atherosclerosis

    PubMed Central

    del Toro, Raquel; Chèvre, Raphael; Rodríguez, Cristina; Ordóñez, Antonio; Martínez-González, José; Andrés, Vicente; Méndez-Ferrer, Simón

    2016-01-01

    Atherosclerosis is a leading death cause. Endothelial and smooth muscle cells participate in atherogenesis, but it is unclear whether other mesenchymal cells contribute to this process. Bone marrow (BM) nestin+ cells cooperate with endothelial cells in directing monocyte egress to bloodstream in response to infections. However, it remains unknown whether nestin+ cells regulate inflammatory cells in chronic inflammatory diseases, such as atherosclerosis. Here, we show that nestin+ cells direct inflammatory cell migration during chronic inflammation. In Apolipoprotein E (ApoE) knockout mice fed with high-fat diet, BM nestin+ cells regulate the egress of inflammatory monocytes and neutrophils. In the aorta, nestin+ stromal cells increase ∼30 times and contribute to the atheroma plaque. Mcp1 deletion in nestin+ cells—but not in endothelial cells only— increases circulating inflammatory cells, but decreases their aortic infiltration, delaying atheroma plaque formation and aortic valve calcification. Therefore, nestin expression marks cells that regulate inflammatory cell migration during atherosclerosis. PMID:27586429

  17. Directing cell migration and organization via nanocrater-patterned cell-repellent interfaces.

    PubMed

    Jeon, Hojeong; Koo, Sangmo; Reese, Willie Mae; Loskill, Peter; Grigoropoulos, Costas P; Healy, Kevin E

    2015-09-01

    Although adhesive interactions between cells and nanostructured interfaces have been studied extensively, there is a paucity of data on how nanostructured interfaces repel cells by directing cell migration and cell-colony organization. Here, by using multiphoton ablation lithography to pattern surfaces with nanoscale craters of various aspect ratios and pitches, we show that the surfaces altered the cells' focal-adhesion size and distribution, thus affecting cell morphology, migration and ultimately localization. We also show that nanocrater pitch can disrupt the formation of mature focal adhesions to favour the migration of cells towards higher-pitched regions, which present increased planar area for the formation of stable focal adhesions. Moreover, by designing surfaces with variable pitch but constant nanocrater dimensions, we were able to create circular and striped cellular patterns. Our surface-patterning approach, which does not involve chemical treatments and can be applied to various materials, represents a simple method to control cell behaviour on surfaces. PMID:26213899

  18. Describing Directional Cell Migration with a Characteristic Directionality Time

    PubMed Central

    Loosley, Alex J.; O’Brien, Xian M.; Reichner, Jonathan S.; Tang, Jay X.

    2015-01-01

    Many cell types can bias their direction of locomotion by coupling to external cues. Characteristics such as how fast a cell migrates and the directedness of its migration path can be quantified to provide metrics that determine which biochemical and biomechanical factors affect directional cell migration, and by how much. To be useful, these metrics must be reproducible from one experimental setting to another. However, most are not reproducible because their numerical values depend on technical parameters like sampling interval and measurement error. To address the need for a reproducible metric, we analytically derive a metric called directionality time, the minimum observation time required to identify motion as directionally biased. We show that the corresponding fit function is applicable to a variety of ergodic, directionally biased motions. A motion is ergodic when the underlying dynamical properties such as speed or directional bias do not change over time. Measuring the directionality of nonergodic motion is less straightforward but we also show how this class of motion can be analyzed. Simulations are used to show the robustness of directionality time measurements and its decoupling from measurement errors. As a practical example, we demonstrate the measurement of directionality time, step-by-step, on noisy, nonergodic trajectories of chemotactic neutrophils. Because of its inherent generality, directionality time ought to be useful for characterizing a broad range of motions including intracellular transport, cell motility, and animal migration. PMID:25992908

  19. Taking Aim at Moving Targets in Computational Cell Migration.

    PubMed

    Masuzzo, Paola; Van Troys, Marleen; Ampe, Christophe; Martens, Lennart

    2016-02-01

    Cell migration is central to the development and maintenance of multicellular organisms. Fundamental understanding of cell migration can, for example, direct novel therapeutic strategies to control invasive tumor cells. However, the study of cell migration yields an overabundance of experimental data that require demanding processing and analysis for results extraction. Computational methods and tools have therefore become essential in the quantification and modeling of cell migration data. We review computational approaches for the key tasks in the quantification of in vitro cell migration: image pre-processing, motion estimation and feature extraction. Moreover, we summarize the current state-of-the-art for in silico modeling of cell migration. Finally, we provide a list of available software tools for cell migration to assist researchers in choosing the most appropriate solution for their needs.

  20. Silencing of VAMP3 inhibits cell migration and integrin-mediated adhesion

    SciTech Connect

    Luftman, Kevin; Hasan, Nazarul; Day, Paul; Hardee, Deborah; Hu Chuan

    2009-02-27

    Integrins are transmembrane receptors for cell adhesion to the extracellular matrix. In cell migration, integrins are endocytosed from the plasma membrane or the cell surface, transported in vesicles and exocytosed actively at the cell front. In the present study, we examined the roles of VAMP3, a SNARE protein that mediates exocytosis, in cell migration and integrin trafficking. Small interfering RNA (siRNA)-induced silencing of VAMP3 inhibited chemotactic cell migration by more than 60% without affecting cell proliferation. VAMP3 silencing reduced the levels of {beta}1 integrin at the cell surface but had no effect on total cellular {beta}1 integrin, indicating that VAMP3 is required for trafficking of {beta}1 integrin to the plasma membrane. Furthermore, VAMP3 silencing diminished cell adhesion to laminin but not to fibronectin or collagen. Taken together, these data suggest that VAMP3-dependent integrin trafficking is crucial in cell migration and cell adhesion to laminin.

  1. Dynamic contact guidance of migrating cells

    NASA Astrophysics Data System (ADS)

    Losert, Wolfgang; Sun, Xiaoyu; Guven, Can; Driscoll, Meghan; Fourkas, John

    2014-03-01

    We investigate the effects of nanotopographical surfaces on the cell migration and cell shape dynamics of the amoeba Dictyostelium discoideum. Amoeboid motion exhibits significant contact guidance along surfaces with nanoscale ridges or grooves. We show quantitatively that nanoridges spaced 1.5 μm apart exhibit the greatest contact guidance efficiency. Using principal component analysis, we characterize the dynamics of the cell shape modulated by the coupling between the cell membrane and ridges. We show that motion parallel to the ridges is enhanced, while the turning, at the largest spatial scales, is suppressed. Since protrusion dynamics are principally governed by actin dynamics, we imaged the actin polymerization of cells on ridges. We found that actin polymerization occurs preferentially along nanoridges in a ``monorail'' like fashion. The ridges then provide us with a tool to study actin dynamics in an effectively reduced dimensional system.

  2. Confinement and low adhesion induce fast amoeboid migration of slow mesenchymal cells.

    PubMed

    Liu, Yan-Jun; Le Berre, Maël; Lautenschlaeger, Franziska; Maiuri, Paolo; Callan-Jones, Andrew; Heuzé, Mélina; Takaki, Tohru; Voituriez, Raphaël; Piel, Matthieu

    2015-02-12

    The mesenchymal-amoeboid transition (MAT) was proposed as a mechanism for cancer cells to adapt their migration mode to their environment. While the molecular pathways involved in this transition are well documented, the role of the microenvironment in the MAT is still poorly understood. Here, we investigated how confinement and adhesion affect this transition. We report that, in the absence of focal adhesions and under conditions of confinement, mesenchymal cells can spontaneously switch to a fast amoeboid migration phenotype. We identified two main types of fast migration--one involving a local protrusion and a second involving a myosin-II-dependent mechanical instability of the cell cortex that leads to a global cortical flow. Interestingly, transformed cells are more prone to adopt this fast migration mode. Finally, we propose a generic model that explains migration transitions and predicts a phase diagram of migration phenotypes based on three main control parameters: confinement, adhesion, and contractility.

  3. T Cell Migration in Rheumatoid Arthritis.

    PubMed

    Mellado, Mario; Martínez-Muñoz, Laura; Cascio, Graciela; Lucas, Pilar; Pablos, José L; Rodríguez-Frade, José Miguel

    2015-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation in joints, associated with synovial hyperplasia and with bone and cartilage destruction. Although the primacy of T cell-related events early in the disease continues to be debated, there is strong evidence that autoantigen recognition by specific T cells is crucial to the pathophysiology of rheumatoid synovitis. In addition, T cells are key components of the immune cell infiltrate detected in the joints of RA patients. Initial analysis of the cytokines released into the synovial membrane showed an imbalance, with a predominance of proinflammatory mediators, indicating a deleterious effect of Th1 T cells. There is nonetheless evidence that Th17 cells also play an important role in RA. T cells migrate from the bloodstream to the synovial tissue via their interactions with the endothelial cells that line synovial postcapillary venules. At this stage, selectins, integrins, and chemokines have a central role in blood cell invasion of synovial tissue, and therefore in the intensity of the inflammatory response. In this review, we will focus on the mechanisms involved in T cell attraction to the joint, the proteins involved in their extravasation from blood vessels, and the signaling pathways activated. Knowledge of these processes will lead to a better understanding of the mechanism by which the systemic immune response causes local joint disorders and will help to provide a molecular basis for therapeutic strategies.

  4. T Cell Migration in Rheumatoid Arthritis

    PubMed Central

    Mellado, Mario; Martínez-Muñoz, Laura; Cascio, Graciela; Lucas, Pilar; Pablos, José L.; Rodríguez-Frade, José Miguel

    2015-01-01

    Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation in joints, associated with synovial hyperplasia and with bone and cartilage destruction. Although the primacy of T cell-related events early in the disease continues to be debated, there is strong evidence that autoantigen recognition by specific T cells is crucial to the pathophysiology of rheumatoid synovitis. In addition, T cells are key components of the immune cell infiltrate detected in the joints of RA patients. Initial analysis of the cytokines released into the synovial membrane showed an imbalance, with a predominance of proinflammatory mediators, indicating a deleterious effect of Th1 T cells. There is nonetheless evidence that Th17 cells also play an important role in RA. T cells migrate from the bloodstream to the synovial tissue via their interactions with the endothelial cells that line synovial postcapillary venules. At this stage, selectins, integrins, and chemokines have a central role in blood cell invasion of synovial tissue, and therefore in the intensity of the inflammatory response. In this review, we will focus on the mechanisms involved in T cell attraction to the joint, the proteins involved in their extravasation from blood vessels, and the signaling pathways activated. Knowledge of these processes will lead to a better understanding of the mechanism by which the systemic immune response causes local joint disorders and will help to provide a molecular basis for therapeutic strategies. PMID:26284069

  5. Microfluidic Assay To Study the Combinatorial Impact of Substrate Properties on Mesenchymal Stem Cell Migration.

    PubMed

    Menon, Nishanth V; Chuah, Yon Jin; Phey, Samantha; Zhang, Ying; Wu, Yingnan; Chan, Vincent; Kang, Yuejun

    2015-08-12

    As an alternative to complex and costly in vivo models, microfluidic in vitro models are being widely used to study various physiological phenomena. It is of particular interest to study cell migration in a controlled microenvironment because of its vital role in a large number of physiological processes, such as wound healing, disease progression, and tissue regeneration. Cell migration has been shown to be affected by variations in the biochemical and physical properties of the extracellular matrix (ECM). To study the combinatorial impact of the ECM physical properties on cell migration, we have developed a microfluidic assay to induce migration of human bone marrow derived mesenchymal stem cells (hBMSCs) on polydimethylsiloxane (PDMS) substrates with varying combinatorial properties (hydrophobicity, stiffness, and roughness). The results show that although the initial cell adhesion and viability appear similar on all PDMS samples, the cell spreading and migration are enhanced on PDMS samples exhibiting intermediate levels of hydrophobicity, stiffness, and roughness. This study suggests that there is a particular range of substrate properties for optimal cell spreading and migration. The influence of substrate properties on hBMSC migration can help understand the physical cues that affect cell migration, which may facilitate the development of optimized engineered scaffolds with desired properties for tissue regeneration applications. PMID:26186177

  6. ERP44 inhibits human lung cancer cell migration mainly via IP3R2.

    PubMed

    Huang, Xue; Jin, Meng; Chen, Ying-Xiao; Wang, Jun; Zhai, Kui; Chang, Yan; Yuan, Qi; Yao, Kai-Tai; Ji, Guangju

    2016-06-01

    Cancer cell migration is involved in tumour metastasis. However, the relationship between calcium signalling and cancer migration is not well elucidated. In this study, we used the human lung adenocarcinoma A549 cell line to examine the role of endoplasmic reticulum protein 44 (ERP44), which has been reported to regulate calcium release inside of the endoplasmic reticulum (ER), in cell migration. We found that the inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs) inhibitor 2-APB significantly inhibited A549 cell migration by inhibiting cell polarization and pseudopodium protrusion, which suggests that Ca2+ is necessary for A549 cell migration. Similarly, the overexpression of ERP44 reduced intracellular Ca2+ release via IP3Rs, altered cell morphology and significantly inhibited the migration of A549 cells. These phenomena were primarily dependent on IP3R2 because wound healing in A549 cells with IP3R2 rather than IP3R1 or IP3R3 siRNA was markedly inhibited. Moreover, the overexpression of ERP44 did not affect the migration of the human neuroblastoma cell line SH-SY5Y, which mainly expresses IP3R1. Based on the above observations, we conclude that ERP44 regulates A549 cell migration mainly via an IP3R2-dependent pathway.

  7. ERP44 inhibits human lung cancer cell migration mainly via IP3R2

    PubMed Central

    Zhai, Kui; Chang, Yan; Yuan, Qi; Yao, Kai-Tai; Ji, Guangju

    2016-01-01

    Cancer cell migration is involved in tumour metastasis. However, the relationship between calcium signalling and cancer migration is not well elucidated. In this study, we used the human lung adenocarcinoma A549 cell line to examine the role of endoplasmic reticulum protein 44 (ERP44), which has been reported to regulate calcium release inside of the endoplasmic reticulum (ER), in cell migration. We found that the inositol 1,4,5-trisphosphate receptors (IP3Rs/ITPRs) inhibitor 2-APB significantly inhibited A549 cell migration by inhibiting cell polarization and pseudopodium protrusion, which suggests that Ca2+ is necessary for A549 cell migration. Similarly, the overexpression of ERP44 reduced intracellular Ca2+ release via IP3Rs, altered cell morphology and significantly inhibited the migration of A549 cells. These phenomena were primarily dependent on IP3R2 because wound healing in A549 cells with IP3R2 rather than IP3R1 or IP3R3 siRNA was markedly inhibited. Moreover, the overexpression of ERP44 did not affect the migration of the human neuroblastoma cell line SH-SY5Y, which mainly expresses IP3R1. Based on the above observations, we conclude that ERP44 regulates A549 cell migration mainly via an IP3R2-dependent pathway. PMID:27347718

  8. Flow-Driven Cell Migration under External Electric Fields

    NASA Astrophysics Data System (ADS)

    Li, Yizeng; Mori, Yoichiro; Sun, Sean X.

    2015-12-01

    Electric fields influence many aspects of cell physiology, including various forms of cell migration. Many cells are sensitive to electric fields, and they can migrate toward a cathode or an anode, depending on the cell type. In this Letter, we examine an actomyosin-independent mode of cell migration under electrical fields. Our theory considers a one-dimensional cell with water and ionic fluxes at the cell boundary. Water fluxes through the membrane are governed by the osmotic pressure difference across the cell membrane. Fluxes of cations and anions across the cell membrane are determined by the properties of the ion channels as well as the external electric field. Results show that without actin polymerization and myosin contraction, electric fields can also drive cell migration, even when the cell is not polarized. The direction of migration with respect to the electric field direction is influenced by the properties of ion channels, and are cell-type dependent.

  9. A simple non-perturbing cell migration assay insensitive to proliferation effects

    PubMed Central

    Glenn, Honor L.; Messner, Jacob; Meldrum, Deirdre R.

    2016-01-01

    Migration is a fundamental cellular behavior that plays an indispensable role in development and homeostasis, but can also contribute to pathology such as cancer metastasis. Due to its relevance to many aspects of human health, the ability to accurately measure cell migration is of broad interest, and numerous approaches have been developed. One of the most commonly employed approaches, because of its simplicity and throughput, is the exclusion zone assay in which cells are allowed to migrate into an initially cell-free region. A major drawback of this assay is that it relies on simply counting cells in the exclusion zone and therefore cannot distinguish the effects of proliferation from migration. We report here a simple modification to the exclusion zone migration assay that exclusively measures cell migration and is not affected by proliferation. This approach makes use of a lineage-tracing vital stain that is retained through cell generations and effectively reads out migration relative to the original, parental cell population. This modification is simple, robust, non-perturbing, and inexpensive. We validate the method in a panel of cell lines under conditions that inhibit or promote migration and demonstrate its use in normal and cancer cell lines as well as primary cells. PMID:27535324

  10. A simple non-perturbing cell migration assay insensitive to proliferation effects.

    PubMed

    Glenn, Honor L; Messner, Jacob; Meldrum, Deirdre R

    2016-01-01

    Migration is a fundamental cellular behavior that plays an indispensable role in development and homeostasis, but can also contribute to pathology such as cancer metastasis. Due to its relevance to many aspects of human health, the ability to accurately measure cell migration is of broad interest, and numerous approaches have been developed. One of the most commonly employed approaches, because of its simplicity and throughput, is the exclusion zone assay in which cells are allowed to migrate into an initially cell-free region. A major drawback of this assay is that it relies on simply counting cells in the exclusion zone and therefore cannot distinguish the effects of proliferation from migration. We report here a simple modification to the exclusion zone migration assay that exclusively measures cell migration and is not affected by proliferation. This approach makes use of a lineage-tracing vital stain that is retained through cell generations and effectively reads out migration relative to the original, parental cell population. This modification is simple, robust, non-perturbing, and inexpensive. We validate the method in a panel of cell lines under conditions that inhibit or promote migration and demonstrate its use in normal and cancer cell lines as well as primary cells. PMID:27535324

  11. Migrating Oligodendrocyte Progenitor Cells Swell Prior to Soma Dislocation

    PubMed Central

    Happel, Patrick; Möller, Kerstin; Schwering, Nina K.; Dietzel, Irmgard D.

    2013-01-01

    The migration of oligodendrocyte progenitor cells (OPCs) to the white matter is an indispensable requirement for an intact brain function. The mechanism of cell migration in general is not yet completely understood. Nevertheless, evidence is accumulating that besides the coordinated rearrangement of the cytoskeleton, a finetuned interplay of ion and water fluxes across the cell membrane is essential for cell migration. One part of a general hypothesis is that a local volume increase towards the direction of movement triggers a mechano-activated calcium influx that regulates various procedures at the rear end of a migrating cell. Here, we investigated cell volume changes of migrating OPCs using scanning ion conductance microscopy. We found that during accelerated migration OPCs undergo an increase in the frontal cell body volume. These findings are supplemented with time lapse calcium imaging data that hint an increase in calcium content the frontal part of the cell soma. PMID:23657670

  12. Mechanisms guiding primordial germ cell migration: strategies from different organisms

    PubMed Central

    Richardson, Brian E.; Lehmann, Ruth

    2015-01-01

    Preface The regulated migration of cells is essential for development and tissue homeostasis, and aberrant cell migration can lead to an impaired immune response and the progression of cancer. Primordial germ cells (PGCs), precursors to sperm and eggs, have to migrate across the embryo to reach somatic gonadal precursors (SGPs) and fulfill their function. Studies of model organisms have revealed that, despite important differences, several features of PGC migration are conserved. PGCs require both an intrinsic motility program and external guidance cues to survive and successfully migrate. Proper guidance involves both attractive and repulsive cues mediated by protein and lipid signalling. PMID:20027186

  13. Vinculin is required for cell polarization, migration, and extracellular matrix remodeling in 3D collagen.

    PubMed

    Thievessen, Ingo; Fakhri, Nikta; Steinwachs, Julian; Kraus, Viola; McIsaac, R Scott; Gao, Liang; Chen, Bi-Chang; Baird, Michelle A; Davidson, Michael W; Betzig, Eric; Oldenbourg, Rudolf; Waterman, Clare M; Fabry, Ben

    2015-11-01

    Vinculin is filamentous (F)-actin-binding protein enriched in integrin-based adhesions to the extracellular matrix (ECM). Whereas studies in 2-dimensional (2D) tissue culture models have suggested that vinculin negatively regulates cell migration by promoting cytoskeleton-ECM coupling to strengthen and stabilize adhesions, its role in regulating cell migration in more physiologic, 3-dimensional (3D) environments is unclear. To address the role of vinculin in 3D cell migration, we analyzed the morphodynamics, migration, and ECM remodeling of primary murine embryonic fibroblasts (MEFs) with cre/loxP-mediated vinculin gene disruption in 3D collagen I cultures. We found that vinculin promoted 3D cell migration by increasing directional persistence. Vinculin was necessary for persistent cell protrusion, cell elongation, and stable cell orientation in 3D collagen, but was dispensable for lamellipodia formation, suggesting that vinculin-mediated cell adhesion to the ECM is needed to convert actin-based cell protrusion into persistent cell shape change and migration. Consistent with this finding, vinculin was necessary for efficient traction force generation in 3D collagen without affecting myosin II activity and promoted 3D collagen fiber alignment and macroscopical gel contraction. Our results suggest that vinculin promotes directionally persistent cell migration and tension-dependent ECM remodeling in complex 3D environments by increasing cell-ECM adhesion and traction force generation.

  14. Light activated cell migration in synthetic extracellular matrices.

    PubMed

    Guo, Qiongyu; Wang, Xiaobo; Tibbitt, Mark W; Anseth, Kristi S; Montell, Denise J; Elisseeff, Jennifer H

    2012-11-01

    Synthetic extracellular matrices provide a framework in which cells can be exposed to defined physical and biological cues. However no method exists to manipulate single cells within these matrices. It is desirable to develop such methods in order to understand fundamental principles of cell migration and define conditions that support or inhibit cell movement within these matrices. Here, we present a strategy for manipulating individual mammalian stem cells in defined synthetic hydrogels through selective optical activation of Rac, which is an intracellular signaling protein that plays a key role in cell migration. Photoactivated cell migration in synthetic hydrogels depended on mechanical and biological cues in the biomaterial. Real-time hydrogel photodegradation was employed to create geometrically defined channels and spaces in which cells could be photoactivated to migrate. Cell migration speed was significantly higher in the photo-etched channels and cells could easily change direction of movement compared to the bulk hydrogels.

  15. Differential migration and proliferation of geometrical ensembles of cell clusters

    SciTech Connect

    Kumar, Girish; Chen, Bo; Co, Carlos C.; Ho, Chia-Chi

    2011-06-10

    Differential cell migration and growth drives the organization of specific tissue forms and plays a critical role in embryonic development, tissue morphogenesis, and tumor invasion. Localized gradients of soluble factors and extracellular matrix have been shown to modulate cell migration and proliferation. Here we show that in addition to these factors, initial tissue geometry can feedback to generate differential proliferation, cell polarity, and migration patterns. We apply layer by layer polyelectrolyte assembly to confine multicellular organization and subsequently release cells to demonstrate the spatial patterns of cell migration and growth. The cell shapes, spreading areas, and cell-cell contacts are influenced strongly by the confining geometry. Cells within geometric ensembles are morphologically polarized. Symmetry breaking was observed for cells on the circular pattern and cells migrate toward the corners and in the direction parallel to the longest dimension of the geometric shapes. This migration pattern is disrupted when actomyosin based tension was inhibited. Cells near the edge or corner of geometric shapes proliferate while cells within do not. Regions of higher rate of cell migration corresponded to regions of concentrated growth. These findings demonstrate that multicellular organization can result in spatial patterns of migration and proliferation.

  16. Water permeation drives tumor cell migration in confined microenvironments.

    PubMed

    Stroka, Kimberly M; Jiang, Hongyuan; Chen, Shih-Hsun; Tong, Ziqiu; Wirtz, Denis; Sun, Sean X; Konstantopoulos, Konstantinos

    2014-04-24

    Cell migration is a critical process for diverse (patho)physiological phenomena. Intriguingly, cell migration through physically confined spaces can persist even when typical hallmarks of 2D planar migration, such as actin polymerization and myosin II-mediated contractility, are inhibited. Here, we present an integrated experimental and theoretical approach ("Osmotic Engine Model") and demonstrate that directed water permeation is a major mechanism of cell migration in confined microenvironments. Using microfluidic and imaging techniques along with mathematical modeling, we show that tumor cells confined in a narrow channel establish a polarized distribution of Na+/H+ pumps and aquaporins in the cell membrane, which creates a net inflow of water and ions at the cell leading edge and a net outflow of water and ions at the trailing edge, leading to net cell displacement. Collectively, this study presents an alternate mechanism of cell migration in confinement that depends on cell-volume regulation via water permeation. PMID:24726433

  17. Water Permeation Drives Tumor Cell Migration in Confined Microenvironments

    PubMed Central

    Stroka, Kimberly M.; Jiang, Hongyuan; Chen, Shih-Hsun; Tong, Ziqiu; Wirtz, Denis; Sun, Sean X.; Konstantopoulos, Konstantinos

    2014-01-01

    SUMMARY Cell migration is a critical process for diverse (patho) physiological phenomena. Intriguingly, cell migration through physically confined spaces can persist even when typical hallmarks of 2D planar migration, such as actin polymerization and myosin II-mediated contractility, are inhibited. Here, we present an integrated experimental and theoretical approach (“Osmotic Engine Model”) and demonstrate that directed water permeation is a major mechanism of cell migration in confined microenvironments. Using microfluidic and imaging techniques along with mathematical modeling, we show that tumor cells confined in a narrow channel establish a polarized distribution of Na+/H+ pumps and aquaporins in the cell membrane, which creates a net inflow of water and ions at the cell leading edge and a net outflow of water and ions at the trailing edge, leading to net cell displacement. Collectively, this study presents an alternate mechanism of cell migration in confinement that depends on cell-volume regulation via water permeation. PMID:24726433

  18. Systems microscopy approaches to understand cancer cell migration and metastasis

    PubMed Central

    Le Dévédec, Sylvia E.; Yan, Kuan; de Bont, Hans; Ghotra, Veerander; Truong, Hoa; Danen, Erik H.; Verbeek, Fons

    2010-01-01

    Cell migration is essential in a number of processes, including wound healing, angiogenesis and cancer metastasis. Especially, invasion of cancer cells in the surrounding tissue is a crucial step that requires increased cell motility. Cell migration is a well-orchestrated process that involves the continuous formation and disassembly of matrix adhesions. Those structural anchor points interact with the extra-cellular matrix and also participate in adhesion-dependent signalling. Although these processes are essential for cancer metastasis, little is known about the molecular mechanisms that regulate adhesion dynamics during tumour cell migration. In this review, we provide an overview of recent advanced imaging strategies together with quantitative image analysis that can be implemented to understand the dynamics of matrix adhesions and its molecular components in relation to tumour cell migration. This dynamic cell imaging together with multiparametric image analysis will help in understanding the molecular mechanisms that define cancer cell migration. PMID:20556632

  19. Lutein inhibits the migration of retinal pigment epithelial cells via cytosolic and mitochondrial Akt pathways (lutein inhibits RPE cells migration).

    PubMed

    Su, Ching-Chieh; Chan, Chi-Ming; Chen, Han-Min; Wu, Chia-Chun; Hsiao, Chien-Yu; Lee, Pei-Lan; Lin, Victor Chia-Hsiang; Hung, Chi-Feng

    2014-08-08

    During the course of proliferative vitreoretinopathy (PVR), the retinal pigment epithelium (RPE) cells will de-differentiate, proliferate, and migrate onto the surfaces of the sensory retina. Several studies have shown that platelet-derived growth factor (PDGF) can induce migration of RPE cells via an Akt-related pathway. In this study, the effect of lutein on PDGF-BB-induced RPE cells migration was examined using transwell migration assays and Western blot analyses. We found that both phosphorylation of Akt and mitochondrial translocation of Akt in RPE cells induced by PDGF-BB stimulation were suppressed by lutein. Furthermore, the increased migration observed in RPE cells with overexpressed mitochondrial Akt could also be suppressed by lutein. Our results demonstrate that lutein can inhibit PDGF-BB induced RPE cells migration through the inhibition of both cytoplasmic and mitochondrial Akt activation.

  20. The effects of laser immunotherapy on cancer cell migration

    NASA Astrophysics Data System (ADS)

    Bahavar, Cody F.; Zhou, Feifan; Hasanjee, Aamr M.; Layton, Elivia; Lam, Anh; Chen, Wei R.; Vaughan, Melville B.

    2016-03-01

    Laser immunotherapy (LIT) uses laser irradiation and immunological stimulation to target all types of metastases and creates a long-term tumor resistance. Glycated chitosan (GC) is the immunological stimulant used in LIT. Interestingly, GC can act as a surfactant for single-walled carbon nanotubes (SWNTs) to immunologically modify SWNTs. SWNT-GC retains the optical properties of SWNTs and the immunological functions of GC to help increase the selectivity of the laser and create a more optimal immune response. One essential aspect of understanding this immune response is knowing how laser irradiation affects cancer cells' ability to metastasize. In this experiment, a cell migration assay was performed. A 2mm circular elastomer plugs were placed at the bottom of multi-well dishes. Pre-cancerous keratinocytes, different tumor cells, and fibroblasts were then plated separately in treated wells. Once the cells reached 100% confluence, they were irradiated by either a 980nm or 805nm wavelength laser. The goal was to determine the effects of laser irradiation and immunological stimulation on cancer cell migration in vitro, paying the way to understand the mechanism of LIT in treating metastatic tumors in cancer patients.

  1. Cell migration does not produce membrane flow

    PubMed Central

    1990-01-01

    We have previously reported that rearward migration of surface particles on slowly moving cells is not driven by membrane flow (Sheetz, M. P., S. Turney, H. Qian, and E. L. Elson. 1989. Nature (Lond.). 340:284-288) and recent photobleaching measurements have ruled out any rapid rearward lipid flow (Lee, J., M. Gustafsson, D. E. Magnussen, and K. Jacobson. 1990. Science (Wash. DC.) 247:1229-1233). It was not possible, however, to conclude from those studies that a slower or tank-tread membrane lipid flow does not occur. Therefore, we have used the technology of single particle tracking to examine the movements of diffusing particles on rapidly locomoting fish keratocytes where the membrane current is likely to be greatest. The keratocytes had a smooth lamellipodial surface on which bound Con A-coated gold particles were observed either to track toward the nuclear region (velocity of 0.35 +/- 0.15 micron/s) or to diffuse randomly (apparent diffusion coefficient of [3.5 +/- 2.0] x 10(-10) cm2/s). We detected no systematic drift relative to the cell edge of particles undergoing random diffusion even after the cell had moved many micrometers. The average net particle displacement was 0.01 +/- 2.7% of the cell displacement. These results strongly suggest that neither the motions of membrane proteins driven by the cytoskeleton nor other possible factors produce a bulk flow of membrane lipid. PMID:2211827

  2. Cell crawling mediates collective cell migration to close undamaged epithelial gaps

    PubMed Central

    Anon, Ester; Serra-Picamal, Xavier; Hersen, Pascal; Gauthier, Nils C.; Sheetz, Michael P.; Trepat, Xavier; Ladoux, Benoît

    2012-01-01

    Fundamental biological processes such as morphogenesis and wound healing involve the closure of epithelial gaps. Epithelial gap closure is commonly attributed either to the purse-string contraction of an intercellular actomyosin cable or to active cell migration, but the relative contribution of these two mechanisms remains unknown. Here we present a model experiment to systematically study epithelial closure in the absence of cell injury. We developed a pillar stencil approach to create well-defined gaps in terms of size and shape within an epithelial cell monolayer. Upon pillar removal, cells actively respond to the newly accessible free space by extending lamellipodia and migrating into the gap. The decrease of gap area over time is strikingly linear and shows two different regimes depending on the size of the gap. In large gaps, closure is dominated by lamellipodium-mediated cell migration. By contrast, closure of gaps smaller than 20 μm was affected by cell density and progressed independently of Rac, myosin light chain kinase, and Rho kinase, suggesting a passive physical mechanism. By changing the shape of the gap, we observed that low-curvature areas favored the appearance of lamellipodia, promoting faster closure. Altogether, our results reveal that the closure of epithelial gaps in the absence of cell injury is governed by the collective migration of cells through the activation of lamellipodium protrusion. PMID:22711834

  3. Cell crawling mediates collective cell migration to close undamaged epithelial gaps.

    PubMed

    Anon, Ester; Serra-Picamal, Xavier; Hersen, Pascal; Gauthier, Nils C; Sheetz, Michael P; Trepat, Xavier; Ladoux, Benoît

    2012-07-01

    Fundamental biological processes such as morphogenesis and wound healing involve the closure of epithelial gaps. Epithelial gap closure is commonly attributed either to the purse-string contraction of an intercellular actomyosin cable or to active cell migration, but the relative contribution of these two mechanisms remains unknown. Here we present a model experiment to systematically study epithelial closure in the absence of cell injury. We developed a pillar stencil approach to create well-defined gaps in terms of size and shape within an epithelial cell monolayer. Upon pillar removal, cells actively respond to the newly accessible free space by extending lamellipodia and migrating into the gap. The decrease of gap area over time is strikingly linear and shows two different regimes depending on the size of the gap. In large gaps, closure is dominated by lamellipodium-mediated cell migration. By contrast, closure of gaps smaller than 20 μm was affected by cell density and progressed independently of Rac, myosin light chain kinase, and Rho kinase, suggesting a passive physical mechanism. By changing the shape of the gap, we observed that low-curvature areas favored the appearance of lamellipodia, promoting faster closure. Altogether, our results reveal that the closure of epithelial gaps in the absence of cell injury is governed by the collective migration of cells through the activation of lamellipodium protrusion. PMID:22711834

  4. Does human migration affect international trade? A complex-network perspective.

    PubMed

    Fagiolo, Giorgio; Mastrorillo, Marina

    2014-01-01

    This paper explores the relationships between international human migration and merchandise trade, using a complex-network approach. We firstly compare the topological structure of worldwide networks of human migration and bilateral trade over the period 1960-2000. Next, we ask whether the position of any pair of countries in the migration network affects their bilateral trade flows. We show that: (i) both weighted and binary versions of the networks of international migration and trade are strongly correlated; (ii) such correlations can be mostly explained by country economic/demographic size and geographical distance; and (iii) pairs of countries that are more central in the international-migration network trade more. Our findings suggest that bilateral trade between any two countries is not only affected by the presence of migrants from either countries but also by their relative embeddedness in the complex web of corridors making up the network of international human migration.

  5. MicroRNA‑21 expression is associated with the clinical features of patients with gastric carcinoma and affects the proliferation, invasion and migration of gastric cancer cells by regulating Noxa.

    PubMed

    Sun, Haibin; Wang, Panzhi; Zhang, Qiangnu; He, Xiaoyan; Zai, Guozhen; Wang, Xudong; Ma, Mei; Sun, Xiaoli

    2016-03-01

    The expression levels of microRNA‑21 (miR‑21) are increased in a number of types of solid tumors. However, the association between miR‑21 expression and clinical features of patients with gastric carcinoma, and gastric cancer proliferation, invasion and migration remains to be elucidated. The present study investigated the effect of miR‑21 on the clinical features, proliferation, invasion and migration of gastric cancer and the underlying mechanisms associated with Noxa. Reverse transcription quantitative polymerase chain reaction (RT‑qPCR) was performed to detect the expression levels of miR‑21 and Noxa in samples of gastric cancer tissue and matched, adjacent, non‑tumor tissue. The association between miR‑21 expression and the clinical features of patients with gastric carcinoma, as well as the correlation between the mRNA and protein expression levels of miR‑21 and Noxa were analyzed. SGC‑7901 gastric cancer cells were cultured in vitro and transfected with an miR‑21 mimic. The effect of miR‑21 upregulation on proliferation and the cell cycle was determined using the MTT assay and flow cytometry. In addition, migration and invasion of SGC‑7901 cells were observed using the Transwell assay. The target gene of miR‑21 was identified using bioinformatics software and a dual luciferase reporting system. The effect of miR‑21 upregulation on Noxa expression levels in SGC‑7901 cells was also analyzed by RT‑qPCR and western blotting. Increased levels of miR‑21 expression and decreased levels of Noxa expression were observed in gastric cancer tissue samples when compared with the adjacent non‑tumor tissue samples. An increased miR‑21 expression level was identified as a risk factor for advanced stage gastric cancer, lymph node metastasis and larger primary tumors. Furthermore, the overexpression of miR‑21 inhibited Noxa expression levels in SGC‑7901 cells. Therefore, high levels of miR‑21 expression may induce gastric cancer

  6. Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma.

    PubMed

    Ramos, Grasieli de Oliveira; Bernardi, Lisiane; Lauxen, Isabel; Sant'Ana Filho, Manoel; Horwitz, Alan Rick; Lamers, Marcelo Lazzaron

    2016-01-01

    Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization. PMID:26978651

  7. Fibronectin Modulates Cell Adhesion and Signaling to Promote Single Cell Migration of Highly Invasive Oral Squamous Cell Carcinoma

    PubMed Central

    Ramos, Grasieli de Oliveira; Bernardi, Lisiane; Lauxen, Isabel; Sant’Ana Filho, Manoel; Horwitz, Alan Rick; Lamers, Marcelo Lazzaron

    2016-01-01

    Cell migration is regulated by adhesion to the extracellular matrix (ECM) through integrins and activation of small RhoGTPases, such as RhoA and Rac1, resulting in changes to actomyosin organization. During invasion, epithelial-derived tumor cells switch from laminin-enriched basal membrane to collagen and fibronectin-enriched connective tissue. How this switch affects the tumor migration is still unclear. We tested the hypothesis that ECM dictates the invasiveness of Oral Squamous Cell Carcinoma (OSCC). We analyzed the migratory properties of two OSCC lines, a low invasive cell line with high e-cadherin levels (Linv/HE-cad) or a highly invasive cell line with low e-cadherin levels (Hinv/LE-cad), plated on different ECM components. Compared to laminin, fibronectin induced non-directional collective migration and decreased RhoA activity in Linv/HE-cad OSCC. For Hinv/LE-cad OSCC, fibronectin increased Rac1 activity and induced smaller adhesions, resulting in a fast single cell migration in both 2D and 3D environments. Consistent with these observations, human OSCC biopsies exhibited similar changes in cell-ECM adhesion distribution at the invasive front of the tumor, where cells encounter fibronectin. Our results indicate that ECM composition might induce a switch from collective to single cell migration according to tumor invasiveness due to changes in cell-ECM adhesion and the resulting signaling pathways that alter actomyosin organization. PMID:26978651

  8. Correlation between cell migration and reactive oxygen species under electric field stimulation.

    PubMed

    Wu, Shang-Ying; Hou, Hsien-San; Sun, Yung-Shin; Cheng, Ji-Yen; Lo, Kai-Yin

    2015-09-01

    Cell migration is an essential process involved in the development and maintenance of multicellular organisms. Electric fields (EFs) are one of the many physical and chemical factors known to affect cell migration, a phenomenon termed electrotaxis or galvanotaxis. In this paper, a microfluidics chip was developed to study the migration of cells under different electrical and chemical stimuli. This chip is capable of providing four different strengths of EFs in combination with two different chemicals via one simple set of agar salt bridges and Ag/AgCl electrodes. NIH 3T3 fibroblasts were seeded inside this chip to study their migration and reactive oxygen species (ROS) production in response to different EF strengths and the presence of β-lapachone. We found that both the EF and β-lapachone level increased the cell migration rate and the production of ROS in an EF-strength-dependent manner. A strong linear correlation between the cell migration rate and the amount of intracellular ROS suggests that ROS are an intermediate product by which EF and β-lapachone enhance cell migration. Moreover, an anti-oxidant, α-tocopherol, was found to quench the production of ROS, resulting in a decrease in the migration rate. PMID:26487906

  9. Neuronal migration and its disorders affecting the CA3 region

    PubMed Central

    Belvindrah, Richard; Nosten-Bertrand, Marika; Francis, Fiona

    2014-01-01

    In this review, we focus on CA3 neuronal migration disorders in the rodent. We begin by introducing the main steps of hippocampal development, and we summarize characteristic hippocampal malformations in human. We then describe various mouse mutants showing structural hippocampal defects. Notably, genes identified in human cortical neuronal migration disorders consistently give rise to a CA3 phenotype when mutated in the mouse. We successively describe their molecular, physiological and behavioral phenotypes that together contribute to a better understanding of CA3-dependent functions. We finally discuss potential factors underlying the CA3 vulnerability revealed by these mouse mutants and that may also contribute to other human neurological and psychiatric disorders. PMID:24624057

  10. Moult Strategies Affect Age Differences in Autumn Migration Timing in East Mediterranean Migratory Passerines.

    PubMed

    Kiat, Yosef; Izhaki, Ido

    2016-01-01

    Adult passerines renew their flight feathers at least once every year. This complete moult occurs either in the breeding areas, just after breeding (summer moult), or, in some long-distance migratory species, at the non-breeding areas, after arrival to the southern wintering area at the end of autumn migration (winter moult). The aim of this study was to relate moult strategies with the DMD, the difference in median migration date, through Israel, between juveniles and adults. Our data on autumn migration timing in juveniles and adults was based on ringing data of 49,125 individuals belonging to 23 passerine species that breed in Europe and Western Asia and migrate through Israel. We found that DMD was associated with moult timing. In all species that perform a winter moult, adults preceded juveniles during autumn. Among migrants who perform a summer moult, we found evidence of both migration timing patterns: juveniles preceding adults or adults preceding juveniles. In addition, in summer moulters, we found a significant, positive correlation between mean breeding latitude and DMD. Although previous studies described that moult duration and extent can be affected by migration, we suggest that moult strategies affect both migration timing and migration strategy. These two moult strategies (summer or winter moult) also represent two unique migration strategies. Our findings highlight the evolutionary interplay between moult and migration strategies.

  11. Moult Strategies Affect Age Differences in Autumn Migration Timing in East Mediterranean Migratory Passerines

    PubMed Central

    Kiat, Yosef; Izhaki, Ido

    2016-01-01

    Adult passerines renew their flight feathers at least once every year. This complete moult occurs either in the breeding areas, just after breeding (summer moult), or, in some long-distance migratory species, at the non-breeding areas, after arrival to the southern wintering area at the end of autumn migration (winter moult). The aim of this study was to relate moult strategies with the DMD, the difference in median migration date, through Israel, between juveniles and adults. Our data on autumn migration timing in juveniles and adults was based on ringing data of 49,125 individuals belonging to 23 passerine species that breed in Europe and Western Asia and migrate through Israel. We found that DMD was associated with moult timing. In all species that perform a winter moult, adults preceded juveniles during autumn. Among migrants who perform a summer moult, we found evidence of both migration timing patterns: juveniles preceding adults or adults preceding juveniles. In addition, in summer moulters, we found a significant, positive correlation between mean breeding latitude and DMD. Although previous studies described that moult duration and extent can be affected by migration, we suggest that moult strategies affect both migration timing and migration strategy. These two moult strategies (summer or winter moult) also represent two unique migration strategies. Our findings highlight the evolutionary interplay between moult and migration strategies. PMID:26797292

  12. Leader Cells Define Directionality of Trunk, but Not Cranial, Neural Crest Cell Migration.

    PubMed

    Richardson, Jo; Gauert, Anton; Briones Montecinos, Luis; Fanlo, Lucía; Alhashem, Zainalabdeen Mohmammed; Assar, Rodrigo; Marti, Elisa; Kabla, Alexandre; Härtel, Steffen; Linker, Claudia

    2016-05-31

    Collective cell migration is fundamental for life and a hallmark of cancer. Neural crest (NC) cells migrate collectively, but the mechanisms governing this process remain controversial. Previous analyses in Xenopus indicate that cranial NC (CNC) cells are a homogeneous population relying on cell-cell interactions for directional migration, while chick embryo analyses suggest a heterogeneous population with leader cells instructing directionality. Our data in chick and zebrafish embryos show that CNC cells do not require leader cells for migration and all cells present similar migratory capacities. In contrast, laser ablation of trunk NC (TNC) cells shows that leader cells direct movement and cell-cell contacts are required for migration. Moreover, leader and follower identities are acquired before the initiation of migration and remain fixed thereafter. Thus, two distinct mechanisms establish the directionality of CNC cells and TNC cells. This implies the existence of multiple molecular mechanisms for collective cell migration.

  13. HIF-1α Promotes A Hypoxia-Independent Cell Migration.

    PubMed

    Li, Liyuan; Madu, Chikezie O; Lu, Andrew; Lu, Yi

    2010-01-01

    Hypoxia-inducible factor-1α (HIF-1α) is known as a transactivator for VEGF gene promoter. It can be induced by hypoxia. However, no study has been done so far to dissect HIF-1α-mediated effects from hypoxia or VEGF-mediated effects. By using a HIF-1α knockout (HIF-1α KO) cell system in mouse embryonic fibroblast (MEF) cells, this study analyzes cell migration and HIF-1α, hypoxia and VEGF activation. A hypoxia-mediated HIF-1α induction and VEGF transactivation were observed: both HIF-1α WT lines had significantly increased VEGF transactivation, as an indicator for HIF-1α induction, in hypoxia compared to normoxia; in contrast, HIF-1α KO line had no increased VEGF transactivation under hypoxia. HIF-1α promotes cell migration: HIF-1α-KO cells had a significantly reduced migration compared to that of the HIF-1α WT cells under both normoxia and hypoxia. The significantly reduced cell migration in HIF-1α KO cells can be partially rescued by the restoration of WT HIF-1α expression mediated by adenoviral-mediated gene transfer. Interestingly, hypoxia has no effect on cell migration: the cells had a similar cell migration rate under hypoxic and normoxic conditions for both HIF-1α WT and HIF-1α KO lines, respectively. Collectively, these data suggest that HIF-1α plays a role in MEF cell migration that is independent from hypoxia-mediated effects.

  14. HIF-1α Promotes A Hypoxia-Independent Cell Migration

    PubMed Central

    Li, Liyuan; Madu, Chikezie O.; Lu, Andrew; Lu, Yi

    2010-01-01

    Hypoxia-inducible factor-1α (HIF-1α) is known as a transactivator for VEGF gene promoter. It can be induced by hypoxia. However, no study has been done so far to dissect HIF-1α-mediated effects from hypoxia or VEGF-mediated effects. By using a HIF-1α knockout (HIF-1α KO) cell system in mouse embryonic fibroblast (MEF) cells, this study analyzes cell migration and HIF-1α, hypoxia and VEGF activation. A hypoxia-mediated HIF-1α induction and VEGF transactivation were observed: both HIF-1α WT lines had significantly increased VEGF transactivation, as an indicator for HIF-1α induction, in hypoxia compared to normoxia; in contrast, HIF-1α KO line had no increased VEGF transactivation under hypoxia. HIF-1α promotes cell migration: HIF-1α-KO cells had a significantly reduced migration compared to that of the HIF-1α WT cells under both normoxia and hypoxia. The significantly reduced cell migration in HIF-1α KO cells can be partially rescued by the restoration of WT HIF-1α expression mediated by adenoviral-mediated gene transfer. Interestingly, hypoxia has no effect on cell migration: the cells had a similar cell migration rate under hypoxic and normoxic conditions for both HIF-1α WT and HIF-1α KO lines, respectively. Collectively, these data suggest that HIF-1α plays a role in MEF cell migration that is independent from hypoxia-mediated effects. PMID:20882121

  15. 3D cancer cell migration in a confined matrix

    NASA Astrophysics Data System (ADS)

    Alobaidi, Amani; Sun, Bo

    Cancer cell migration is widely studied in 2D motion, which does not mimic the invasion processes in vivo. More recently, 3D cell migration studies have been performed. The ability of cancer cells to migrate within the extracellular matrix depends on the physical and biochemical features of the extracellular matrix. We present a model of cell motility in confined matrix geometry. The aim of the study is to study cancer migration in collagen matrix, as a soft tissue, to investigate their motility within the confined and surrounding collagen environment. Different collagen concentrations have been used to show the ability of these cancer cells to move through such a complex structure by measuring Cancer cell migration velocity as well as the displacement. Graduate student physics department.

  16. Physical role for the nucleus in cell migration.

    PubMed

    Fruleux, Antoine; Hawkins, Rhoda J

    2016-09-14

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration.

  17. Physical role for the nucleus in cell migration

    NASA Astrophysics Data System (ADS)

    Fruleux, Antoine; Hawkins, Rhoda J.

    2016-09-01

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration.

  18. Physical role for the nucleus in cell migration.

    PubMed

    Fruleux, Antoine; Hawkins, Rhoda J

    2016-09-14

    Cell migration is important for the function of many eukaryotic cells. Recently the nucleus has been shown to play an important role in cell motility. After giving an overview of cell motility mechanisms we review what is currently known about the mechanical properties of the nucleus and the connections between it and the cytoskeleton. We also discuss connections to the extracellular matrix and mechanotransduction. We identify key physical roles of the nucleus in cell migration. PMID:27406341

  19. Follow-the-leader cell migration requires biased cell-cell contact and local microenvironmental signals.

    PubMed

    Wynn, Michelle L; Rupp, Paul; Trainor, Paul A; Schnell, Santiago; Kulesa, Paul M

    2013-06-01

    Directed cell migration often involves at least two types of cell motility that include multicellular streaming and chain migration. However, what is unclear is how cell contact dynamics and the distinct microenvironments through which cells travel influence the selection of one migratory mode or the other. The embryonic and highly invasive neural crest (NC) are an excellent model system to study this question since NC cells have been observed in vivo to display both of these types of cell motility. Here, we present data from tissue transplantation experiments in chick and in silico modeling that test our hypothesis that cell contact dynamics with each other and the microenvironment promote and sustain either multicellular stream or chain migration. We show that when premigratory cranial NC cells (at the pre-otic level) are transplanted into a more caudal region in the head (at the post-otic level), cells alter their characteristic stream behavior and migrate in chains. Similarly, post-otic NC cells migrate in streams after transplantation into the pre-otic hindbrain, suggesting that local microenvironmental signals dictate the mode of NC cell migration. Simulations of an agent-based model (ABM) that integrates the NC cell behavioral data predict that chain migration critically depends on the interplay of biased cell-cell contact and local microenvironment signals. Together, this integrated modeling and experimental approach suggests new experiments and offers a powerful tool to examine mechanisms that underlie complex cell migration patterns.

  20. An open data ecosystem for cell migration research.

    PubMed

    Masuzzo, Paola; Martens, Lennart; Ampe, Christophe; Anderson, Kurt I; Barry, Joseph; De Wever, Olivier; Debeir, Olivier; Decaestecker, Christine; Dolznig, Helmut; Friedl, Peter; Gaggioli, Cedric; Geiger, Benjamin; Goldberg, Ilya G; Horn, Elias; Horwitz, Rick; Kam, Zvi; Le Dévédec, Sylvia E; Vignjevic, Danijela Matic; Moore, Josh; Olivo-Marin, Jean-Christophe; Sahai, Erik; Sansone, Susanna A; Sanz-Moreno, Victoria; Strömblad, Staffan; Swedlow, Jason; Textor, Johannes; Van Troys, Marleen; Zantl, Roman

    2015-02-01

    Cell migration research has recently become both a high content and a high throughput field thanks to technological, computational, and methodological advances. Simultaneously, however, urgent bioinformatics needs regarding data management, standardization, and dissemination have emerged. To address these concerns, we propose to establish an open data ecosystem for cell migration research.

  1. Screening of genes involved in cell migration in Dictyostelium.

    PubMed

    Nagasaki, Akira; Uyeda, Taro Q P

    2008-03-10

    A single cell of wild-type Dictyostelium discoideum forms a visible colony on a plastic dish in several days, but due to enhanced cell migration, amiB-null mutant cells scatter over a large area and do not form noticeable colonies. Here, with an aim to identify genes involved in cell migration, we isolated suppresser mutants of amiB-null mutants that restore the ability to form colonies. From REMI (restriction enzyme-mediated integration)-mutagenized pool of double-mutants, we identified 18 responsible genes from them. These genes can be categorized into several biological processes. One cell line, Sab16 (Suppressor of amiB) was chosen for further analysis, which had a disrupted phospholipase D pldB gene. To confirm the role of pldB gene in cell migration, we knocked out the pldB gene and over-expressed gfp-pldB in wild-type cells. GFP-PLDB localized to plasma membrane and on vesicles, and in migrating cells, at the protruding regions of pseudopodia. Migration speed of vegetative pldB-null cells was reduced to 73% of that of the wild-type. These results suggest that PLDB plays an important role in migration in Dictyostelium cells, and that our screening system is useful for the identification of genes involved in cell migration. PMID:18164290

  2. Osteoactivin Promotes Migration of Oral Squamous Cell Carcinomas.

    PubMed

    Arosarena, Oneida A; Dela Cadena, Raul A; Denny, Michael F; Bryant, Evan; Barr, Eric W; Thorpe, Ryan; Safadi, Fayez F

    2016-08-01

    Nearly 50% of patients with oral squamous cell carcinoma (OSCC) die of metastases or locoregional recurrence. Metastasis is mediated by cancer cell adhesion, migration, and invasion. Osteoactivin (OA) overexpression plays a role in metastases in several malignancies. The aims were to determine how integrin interactions modulate OA-induced OSCC cell migration; and to investigate OA effects on cell survival and proliferation. We confirmed OA mRNA and protein overexpression in OSCC cell lines. We assessed OA's interactions with integrins using adhesion inhibition assays, fluorescent immunocytochemistry and co-immunoprecipitation. We investigated OA-mediated activation of mitogen-activated protein kinases (MAPKs) and cell survival. Integrin inhibition effects on OA-mediated cell migration were determined. We assessed effects of OA knock-down on cell migration and proliferation. OA is overexpressed in OSCC cell lines, and serves as a migration-promoting adhesion molecule. OA co-localized with integrin subunits, and co-immunoprecipitated with the subunits. Integrin blocking antibodies, especially those directed against the β1 subunit, inhibited cell adhesion (P = 0.03 for SCC15 cells). Adhesion to OA activated MAPKs in UMSCC14a cells and OA treatment promoted survival of SCC15 cells. Integrin-neutralizing antibodies enhanced cell migration with OA in the extracellular matrix. OA knock-down resulted in decreased proliferation of SCC15 and SCC25 cells, but did not inhibit cell migration. OA in the extracellular matrix promotes OSCC cell adhesion and migration, and may be a novel target in the prevention of HNSCC spread. J. Cell. Physiol. 231: 1761-1770, 2016. © 2015 Wiley Periodicals, Inc. PMID:26636434

  3. Osteoactivin Promotes Migration of Oral Squamous Cell Carcinomas.

    PubMed

    Arosarena, Oneida A; Dela Cadena, Raul A; Denny, Michael F; Bryant, Evan; Barr, Eric W; Thorpe, Ryan; Safadi, Fayez F

    2016-08-01

    Nearly 50% of patients with oral squamous cell carcinoma (OSCC) die of metastases or locoregional recurrence. Metastasis is mediated by cancer cell adhesion, migration, and invasion. Osteoactivin (OA) overexpression plays a role in metastases in several malignancies. The aims were to determine how integrin interactions modulate OA-induced OSCC cell migration; and to investigate OA effects on cell survival and proliferation. We confirmed OA mRNA and protein overexpression in OSCC cell lines. We assessed OA's interactions with integrins using adhesion inhibition assays, fluorescent immunocytochemistry and co-immunoprecipitation. We investigated OA-mediated activation of mitogen-activated protein kinases (MAPKs) and cell survival. Integrin inhibition effects on OA-mediated cell migration were determined. We assessed effects of OA knock-down on cell migration and proliferation. OA is overexpressed in OSCC cell lines, and serves as a migration-promoting adhesion molecule. OA co-localized with integrin subunits, and co-immunoprecipitated with the subunits. Integrin blocking antibodies, especially those directed against the β1 subunit, inhibited cell adhesion (P = 0.03 for SCC15 cells). Adhesion to OA activated MAPKs in UMSCC14a cells and OA treatment promoted survival of SCC15 cells. Integrin-neutralizing antibodies enhanced cell migration with OA in the extracellular matrix. OA knock-down resulted in decreased proliferation of SCC15 and SCC25 cells, but did not inhibit cell migration. OA in the extracellular matrix promotes OSCC cell adhesion and migration, and may be a novel target in the prevention of HNSCC spread. J. Cell. Physiol. 231: 1761-1770, 2016. © 2015 Wiley Periodicals, Inc.

  4. Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos).

    PubMed

    Hill, Nichola J; Takekawa, John Y; Ackerman, Joshua T; Hobson, Keith A; Herring, Garth; Cardona, Carol J; Runstadler, Jonathan A; Boyce, Walter M

    2012-12-01

    Studies of pathogen transmission typically overlook that wildlife hosts can include both migrant and resident populations when attempting to model circulation. Through the application of stable isotopes in flight feathers, we estimated the migration strategy of mallards (Anas platyrhynchos) occurring on California wintering grounds. Our study demonstrates that mallards- a principal host of avian influenza virus (AIV) in nature, contribute differently to virus gene flow depending on migration strategy. No difference in AIV prevalence was detected between resident (9.6%), intermediate-distance (9.6%) and long-distance migrants (7.4%). Viral diversity among the three groups was also comparable, possibly owing to viral pool mixing when birds converge at wetlands during winter. However, migrants and residents contributed differently to the virus gene pool at wintering wetlands. Migrants introduced virus from northern breeding grounds (Alaska and the NW Pacific Rim) into the wintering population, facilitating gene flow at continental scales, but circulation of imported virus appeared to be limited. In contrast, resident mallards acted as AIV reservoirs facilitating year-round circulation of limited subtypes (i.e. H5N2) at lower latitudes. This study supports a model of virus exchange in temperate regions driven by the convergence of wild birds with separate geographic origins and exposure histories. PMID:22971007

  5. Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos).

    USGS Publications Warehouse

    Takekawa, John Y.; Hill, Nichola J.; Ackerman, Joshua T.; Herring, Garth; Hobson, Keith; Cardona, Carol J.; Runstadler, Jonathan; Boyce, Walter M.

    2012-01-01

    Studies of pathogen transmission typically overlook that wildlife hosts can include both migrant and resident populations when attempting to model circulation. Through the application of stable isotopes in flight feathers, we estimated the migration strategy of mallards (Anas platyrhynchos) occurring on California wintering grounds. Our study demonstrates that mallards- a principal host of avian influenza virus (AIV) in nature, contribute differently to virus gene flow depending on migration strategy. No difference in AIV prevalence was detected between resident (9.6%), intermediate-distance (9.6%) and long-distance migrants (7.4%). Viral diversity among the three groups was also comparable, possibly owing to viral pool mixing when birds converge at wetlands during winter. However, migrants and residents contributed differently to the virus gene pool at wintering wetlands. Migrants introduced virus from northern breeding grounds (Alaska and the NW Pacific Rim) into the wintering population, facilitating gene flow at continental scales, but circulation of imported virus appeared to be limited. In contrast, resident mallards acted as AIV reservoirs facilitating year-round circulation of limited subtypes (i.e. H5N2) at lower latitudes. This study supports a model of virus exchange in temperate regions driven by the convergence of wild birds with separate geographic origins and exposure histories.

  6. Migration strategy affects avian influenza dynamics in mallards (Anas platyrhynchos).

    PubMed

    Hill, Nichola J; Takekawa, John Y; Ackerman, Joshua T; Hobson, Keith A; Herring, Garth; Cardona, Carol J; Runstadler, Jonathan A; Boyce, Walter M

    2012-12-01

    Studies of pathogen transmission typically overlook that wildlife hosts can include both migrant and resident populations when attempting to model circulation. Through the application of stable isotopes in flight feathers, we estimated the migration strategy of mallards (Anas platyrhynchos) occurring on California wintering grounds. Our study demonstrates that mallards- a principal host of avian influenza virus (AIV) in nature, contribute differently to virus gene flow depending on migration strategy. No difference in AIV prevalence was detected between resident (9.6%), intermediate-distance (9.6%) and long-distance migrants (7.4%). Viral diversity among the three groups was also comparable, possibly owing to viral pool mixing when birds converge at wetlands during winter. However, migrants and residents contributed differently to the virus gene pool at wintering wetlands. Migrants introduced virus from northern breeding grounds (Alaska and the NW Pacific Rim) into the wintering population, facilitating gene flow at continental scales, but circulation of imported virus appeared to be limited. In contrast, resident mallards acted as AIV reservoirs facilitating year-round circulation of limited subtypes (i.e. H5N2) at lower latitudes. This study supports a model of virus exchange in temperate regions driven by the convergence of wild birds with separate geographic origins and exposure histories.

  7. Does Human Migration Affect International Trade? A Complex-Network Perspective

    PubMed Central

    Fagiolo, Giorgio; Mastrorillo, Marina

    2014-01-01

    This paper explores the relationships between international human migration and merchandise trade using a complex-network approach. We firstly compare the topological structure of worldwide networks of human migration and bilateral trade over the period 1960–2000. Next, we ask whether pairs of countries that are more central in the migration network trade more. We show that: (i) the networks of international migration and trade are strongly correlated, and such correlation can be mostly explained by country economic/demographic size and geographical distance; (ii) centrality in the international-migration network boosts bilateral trade; (iii) intensive forms of country centrality are more trade enhancing than their extensive counterparts. Our findings suggest that bilateral trade between any two countries is not only affected by the presence of migrants from either countries, but also by their relative embeddedness in the complex web of corridors making up the network of international human migration. PMID:24828376

  8. Role of Cortactin Homolog HS1 in Transendothelial Migration of Natural Killer Cells

    PubMed Central

    Mukherjee, Suranjana; Kim, Joanna; Mooren, Olivia L.; Shahan, Stefanie T.; Cohan, Megan; Cooper, John A.

    2015-01-01

    Natural Killer (NK) cells perform many functions that depend on actin assembly, including adhesion, chemotaxis, lytic synapse assembly and cytolysis. HS1, the hematopoietic homolog of cortactin, binds to Arp2/3 complex and promotes actin assembly by helping to form and stabilize actin filament branches. We investigated the role of HS1 in transendothelial migration (TEM) by NK cells. Depletion of HS1 led to a decrease in the efficiency of TEM by NK cells, as measured by transwell assays with endothelial cell monolayers on porous filters. Transwell assays involve chemotaxis of NK cells across the filter, so to examine TEM more specifically, we imaged live-cell preparations and antibody-stained fixed preparations, with and without the chemoattractant SDF-1α. We found small to moderate effects of HS1 depletion on TEM, including whether the NK cells migrated via the transcellular or paracellular route. Expression of HS1 mutants indicated that phosphorylation of HS1 tyrosines at positions 222, 378 and 397 was required for rescue in the transwell assay, but HS1 mutations affecting interaction with Arp2/3 complex or SH3-domain ligands had no effect. The GEF Vav1, a ligand of HS1 phosphotyrosine, influenced NK cell transendothelial migration. HS1 and Vav1 also affected the speed of NK cells migrating across the surface of the endothelium. We conclude that HS1 has a role in transendothelial migration of NK cells and that HS1 tyrosine phosphorylation may signal through Vav1. PMID:25723543

  9. Neuronal Neuregulin 1 type III directs Schwann cell migration

    PubMed Central

    Perlin, Julie R.; Lush, Mark E.; Stephens, W. Zac; Piotrowski, Tatjana; Talbot, William S.

    2011-01-01

    During peripheral nerve development, each segment of a myelinated axon is matched with a single Schwann cell. Tight regulation of Schwann cell movement, proliferation and differentiation is essential to ensure that these glial cells properly associate with axons. ErbB receptors are required for Schwann cell migration, but the operative ligand and its mechanism of action have remained unknown. We demonstrate that zebrafish Neuregulin 1 (Nrg1) type III, which signals through ErbB receptors, controls Schwann cell migration in addition to its previously known roles in proliferation and myelination. Chimera analyses indicate that ErbB receptors are required in all migrating Schwann cells, and that Nrg1 type III is required in neurons for migration. Surprisingly, expression of the ligand in a few axons is sufficient to induce migration along a chimeric nerve constituted largely of nrg1 type III mutant axons. These studies also reveal a mechanism that allows Schwann cells to fasciculate axons regardless of nrg1 type III expression. Time-lapse imaging of transgenic embryos demonstrated that misexpression of human NRG1 type III results in ectopic Schwann cell migration, allowing them to aberrantly enter the central nervous system. These results demonstrate that Nrg1 type III is an essential signal that controls Schwann cell migration to ensure that these glia are present in the correct numbers and positions in developing nerves. PMID:21965611

  10. Silk Film Topography Directs Collective Epithelial Cell Migration

    PubMed Central

    Rosenblatt, Mark I.

    2012-01-01

    The following study provides new insight into how surface topography dictates directed collective epithelial cell sheet growth through the guidance of individual cell movement. Collective cell behavior of migrating human corneal limbal-epithelial cell sheets were studied on highly biocompatible flat and micro-patterned silk film surfaces. The silk film edge topography guided the migratory direction of individual cells making up the collective epithelial sheet, which resulted in a 75% increase in total culture elongation. This was due to a 3-fold decrease in cell sheet migration rate efficiency for movement perpendicular to the topography edge. Individual cell migration direction is preferred in the parallel approach to the edge topography where localization of cytoskeletal proteins to the topography’s edge region is reduced, which results in the directed growth of the collective epithelial sheet. Findings indicate customized biomaterial surfaces may be created to direct both the migration rate and direction of tissue epithelialization. PMID:23185573

  11. Lamellipodia and Membrane Blebs Drive Efficient Electrotactic Migration of Rat Walker Carcinosarcoma Cells WC 256

    PubMed Central

    Sroka, Jolanta; Krecioch, Izabela; Zimolag, Eliza; Lasota, Slawomir; Rak, Monika; Kedracka-Krok, Sylwia; Borowicz, Pawel; Gajek, Marta; Madeja, Zbigniew

    2016-01-01

    The endogenous electric field (EF) may provide an important signal for directional cell migration during wound healing, embryonic development and cancer metastasis but the mechanism of cell electrotaxis is poorly understood. Additionally, there is no research addressing the question on the difference in electrotactic motility of cells representing various strategies of cell movement—specifically blebbing vs. lamellipodial migration. In the current study we constructed a unique experimental model which allowed for the investigation of electrotactic movement of cells of the same origin but representing different modes of cell migration: weakly adherent, spontaneously blebbing (BC) and lamellipodia forming (LC) WC256 cells. We report that both BC and LC sublines show robust cathodal migration in a physiological EF (1–3 V/cm). The directionality of cell movement was completely reversible upon reversing the field polarity. However, the full reversal of cell direction after the change of EF polarity was much faster in the case of BC (10 minutes) than LC cells (30 minutes). We also investigated the distinct requirements for Rac, Cdc42 and Rho pathways and intracellular Ca2+ in electrotaxis of WC256 sublines forming different types of cell protrusions. It was found that Rac1 is required for directional movement of LC to a much greater extent than for BC, but Cdc42 and RhoA are more crucial for BC than for LC cells. The inhibition of ROCK did not affect electrotaxis of LC in contrast to BC cells. The results also showed that intracellular Ca2+ is essential only for the electrotactic reaction of BC cells. Moreover, inhibition of MLCK and myosin II did not affect the electrotaxis of LC in contrast to BC cells. In conclusion, our results revealed that both lamellipodia and membrane blebs can efficiently drive electrotactic migration of WC 256 carcinosarcoma cells, however directional migration is mediated by different signalling pathways. PMID:26863616

  12. Colonizing while migrating: how do individual enteric neural crest cells behave?

    PubMed Central

    2014-01-01

    Background Directed cell migration is essential for normal development. In most of the migratory cell populations that have been analyzed in detail to date, all of the cells migrate as a collective from one location to another. However, there are also migratory cell populations that must populate the areas through which they migrate, and thus some cells get left behind while others advance. Very little is known about how individual cells behave to achieve concomitant directional migration and population of the migratory route. We examined the behavior of enteric neural crest-derived cells (ENCCs), which must both advance caudally to reach the anal end and populate each gut region. Results The behavior of individual ENCCs was examined using live imaging and mice in which ENCCs express a photoconvertible protein. We show that individual ENCCs exhibit very variable directionalities and speed; as the migratory wavefront of ENCCs advances caudally, each gut region is populated primarily by some ENCCs migrating non-directionally. After populating each region, ENCCs remain migratory for at least 24 hours. Endothelin receptor type B (EDNRB) signaling is known to be essential for the normal advance of the ENCC population. We now show that perturbation of EDNRB principally affects individual ENCC speed rather than directionality. The trajectories of solitary ENCCs, which occur transiently at the wavefront, were consistent with an unbiased random walk and so cell-cell contact is essential for directional migration. ENCCs migrate in close association with neurites. We showed that although ENCCs often use neurites as substrates, ENCCs lead the way, neurites are not required for chain formation and neurite growth is more directional than the migration of ENCCs as a whole. Conclusions Each gut region is initially populated by sub-populations of ENCCs migrating non-directionally, rather than stopping. This might provide a mechanism for ensuring a uniform density of ENCCs along the

  13. Redundant control of migration and adhesion by ERM proteins in vascular smooth muscle cells

    SciTech Connect

    Baeyens, Nicolas; Latrache, Iman; Yerna, Xavier; Noppe, Gauthier; Horman, Sandrine; Morel, Nicole

    2013-11-22

    Highlights: •The three ERM proteins are expressed in vascular smooth muscle cell. •ERM depletion inhibited PDGF-evoked migration redundantly. •ERM depletion increased cell adhesion redundantly. •ERM depletion did not affect PDGF-evoked Ca signal, Rac1 activation, proliferation. •ERM proteins control PDGF-induced migration by regulating adhesion. -- Abstract: Ezrin, radixin, and moesin possess a very similar structure with a C-terminal actin-binding domain and a N-terminal FERM interacting domain. They are known to be involved in cytoskeleton organization in several cell types but their function in vascular smooth muscle cells (VSMC) is still unknown. The aim of this study was to investigate the role of ERM proteins in cell migration induced by PDGF, a growth factor involved in pathophysiological processes like angiogenesis or atherosclerosis. We used primary cultured VSMC obtained from rat aorta, which express the three ERM proteins. Simultaneous depletion of the three ERM proteins with specific siRNAs abolished the effects of PDGF on cell architecture and migration and markedly increased cell adhesion and focal adhesion size, while these parameters were only slightly affected by depletion of ezrin, radixin or moesin alone. Rac1 activation, cell proliferation, and Ca{sup 2+} signal in response to PDGF were unaffected by ERM depletion. These results indicate that ERM proteins exert a redundant control on PDGF-induced VSMC migration by regulating focal adhesion turn-over and cell adhesion to substrate.

  14. Cell migration in the normal and pathological postnatal mammalian brain

    PubMed Central

    Canoll, Peter; Goldman, James E.

    2009-01-01

    In the developing brain, cell migration is a crucial process for structural organization, and is therefore highly regulated to allow the correct formation of complex networks, wiring neurons, and glia. In the early postnatal brain, late developmental processes such as the production and migration of astrocyte and oligodendrocyte progenitors still occur. Although the brain is completely formed and structured few weeks after birth, it maintains a degree of plasticity throughout life, including axonal remodeling, synaptogenesis, but also neural cell birth, migration and integration. The subventricular zone (SVZ) and the dentate gyrus of the hippocampus (DG) are the two main neurogenic niches in the adult brain. Neural stem cells reside in these structures and produce progenitors that migrate toward their ultimate location: the olfactory bulb and granular cell layer of the DG respectively. The aim of this review is to synthesize the increasing information concerning the organization, regulation and function of cell migration in a mature brain. In a normal brain, protein involved in cell-cell or cell-matrix interactions together with secreted proteins acting as chemoattractant or chemorepellant play key roles in the regulation of neural progenitor cell migration. In addition, recent data suggest that gliomas arise from the transformation of neural stem cells or progenitor cells and that glioma cell infiltration recapitulates key aspects of glial progenitor migration. Thus, we will consider glioma migration in the context of progenitor migration. Finally, many observations show that brain lesions and neurological diseases trigger neural stem/progenitor cell activation and migration towards altered structures. The factors involved in such cell migration/recruitment are just beginning to be understood. Inflammation which has long been considered as thoroughly disastrous for brain repair is now known to produce some positive effects on stem/progenitor cell recruitment via

  15. Single cell migration dynamics mediated by geometric confinement.

    PubMed

    Zhang, Hua; Hou, Ruixia; Xiao, Peng; Xing, Rubo; Chen, Tao; Han, Yanchun; Ren, Penggang; Fu, Jun

    2016-09-01

    The migration dynamics of cells plays a key role in tissue engineering and regenerative medicine. Previous studies mostly focus on regulating stem cell fate and phenotype by biophysical cues. In contrast, less is known about how the geometric cues mediate the migration dynamics of cells. Here, we fabricate graphene oxide (GO) microstripes on cell non-adhesive PEG substrate by using micromolding in capillary (MIMIC) method. Such micropatterns with alternating cell adhesion and cell resistance enable an effective control of selective adhesion and migration of single cells. The sharp contrast in cell adhesion minimizes the invasion of cells into the PEG patterns, and thereby strongly confines the cells on GO microstripes. As a result, the cells are forced to adapt highly polarized, elongated, and oriented geometry to fit the patterns. A series of pattern widths have been fabricated to modulate the extent of cell deformation and polarization. Under strong confinement, the cytoskeleton contractility, intracellular traction, and actin filament elongation are highly promoted, which result in enhanced cell migration along the patterns. This work provides an important insight into developing combinatorial graphene-based patterns for the control of cell migration dynamics, which is of great significance for tissue engineering and regenerative medicine. PMID:27137805

  16. Extracellular glutathione promotes migration of hydrogen peroxide-stressed cultured chick embryonic skin cells.

    PubMed

    Denunzio, Mia; Gomez, George

    2014-04-01

    The ability of glutathione to affect melanocyte survival has fostered its use in a variety of applications related to epithelial cells. Our study focused on fibroblast migration and the effects of oxidative stress. We used scratch assays to measure cell migration: fibroblasts were harvested from embryonic chicks, grown to confluence in a monolayer, and the layer was scratched to initiate migration. Migration rates were measured over 8 h using photomicrographs, and vinculin expression as an indicator focal adhesion formation was measured using immunofluorescence. Addition of 200 μM glutathione to the culture media in which the cells grew resulted in a significantly increased rate of scratch closure. When the scratch assays were performed in the presence of 100 μM H2O2 (to simulate oxidative stress), the cells ceased to migrate. Addition of 200 μM glutathione to the H2O2-treated scratched layers resulted in a restoration of the scratch closure capabilities. At the subcellular level, addition of extracellular glutathione resulted in a redistribution of vinculin into fewer but larger aggregates. In cells at the edge of scratched monolayers that were treated with H2O2, vinculin particles were distributed throughout the cell in smaller aggregates; addition of glutathione resulted in vinculin aggregates that were larger and closer to the edges of the cell, indicating that these cells were more migratory. Our results suggest that glutathione promotes fibroblast migration, possibly via a mechanism that promotes the formation of focal adhesions.

  17. Glass-like dynamics in collective cell migration

    NASA Astrophysics Data System (ADS)

    Angelini, Thomas; Weitz, David

    2011-03-01

    The collective movement of tissue cells is essential to fundamental biological processes in both health and disease, and occurs throughout embryonic development, during wound healing, and in cancerous tumor invasion. Most knowledge of cell migration, however, comes from single cell studies. Single cells migrate by executing cyclic processes of extension, adhesion, and retraction, during which the cell body fluctuates dramatically and the cell changes direction erratically. These sub-cellular motions must be coupled between neighbors in confluent layers, yet the influence of this coupling on collective migration is not known. In this talk we present a study of motion in confluent epithelial cell sheets. We measure collective migration and sub-cellular motions, covering a broad range of length-scales, time-scales, and cell densities. We find that that collective cell migration exhibits many behaviors characteristic of classical supercooled particulate fluids, including growing dynamic heterogeneities in the migration velocity field, non-Arrhenius relaxation behavior, and peaks in the density of states analogous to the Boson peak. These results provide a suggestive analogy between collective cell motion and the dynamics of supercooled fluids approaching a glass transition.

  18. Reduced migration of Ishikawa cells associated with downregulation of aquaporin-5

    PubMed Central

    JIANG, XIU XIU; XU, KAI HONG; MA, JUN YAN; TIAN, YONG HONG; GUO, XIAO YAN; LIN, JUN; WU, RUI JIN

    2012-01-01

    Aquaporin (AQP)-dependent cell migration has broad implications in angiogenesis, tumor metastasis, wound healing, glial scarring and other events requiring cell movement. There are 13 isoforms of AQP (0–12) that have been identified in mammals. It is unclear whether AQP5 plays a role in the development of endometrial cancer. We recently demonstrated that ovarian steroids may affect the expression of AQP5 in the female genital tract. In this study, we considered whether AQP5 may affect cell migration in Ishikawa cells, an adenocarcinoma cell line derived from the endometrium. The results showed that the downregulation of AQP5 results in reduced Ishikawa cell migration. The estrogen (E2) receptor in the promoter of AQP5 mediated the regulation of AQP5 expression in the normal endometrium and endometrial cancer. By contrast, the upregulation of AQP5 by E2 increased cell migration, invasion and adhesion through increased annexin-2, which is responsible for F-actin remodeling and rearrangement. E2 regulates Ishikawa cell migration by regulating the AQP5 expression. PMID:22844365

  19. Ring-Shaped Microlanes and Chemical Barriers as a Platform for Probing Single-Cell Migration

    PubMed Central

    Schreiber, Christoph; Segerer, Felix J.; Wagner, Ernst; Roidl, Andreas; Rädler, Joachim O.

    2016-01-01

    Quantification and discrimination of pharmaceutical and disease-related effects on cell migration requires detailed characterization of single-cell motility. In this context, micropatterned substrates that constrain cells within defined geometries facilitate quantitative readout of locomotion. Here, we study quasi-one-dimensional cell migration in ring-shaped microlanes. We observe bimodal behavior in form of alternating states of directional migration (run state) and reorientation (rest state). Both states show exponential lifetime distributions with characteristic persistence times, which, together with the cell velocity in the run state, provide a set of parameters that succinctly describe cell motion. By introducing PEGylated barriers of different widths into the lane, we extend this description by quantifying the effects of abrupt changes in substrate chemistry on migrating cells. The transit probability decreases exponentially as a function of barrier width, thus specifying a characteristic penetration depth of the leading lamellipodia. Applying this fingerprint-like characterization of cell motion, we compare different cell lines, and demonstrate that the cancer drug candidate salinomycin affects transit probability and resting time, but not run time or run velocity. Hence, the presented assay allows to assess multiple migration-related parameters, permits detailed characterization of cell motility, and has potential applications in cell biology and advanced drug screening. PMID:27242099

  20. Ring-Shaped Microlanes and Chemical Barriers as a Platform for Probing Single-Cell Migration.

    PubMed

    Schreiber, Christoph; Segerer, Felix J; Wagner, Ernst; Roidl, Andreas; Rädler, Joachim O

    2016-01-01

    Quantification and discrimination of pharmaceutical and disease-related effects on cell migration requires detailed characterization of single-cell motility. In this context, micropatterned substrates that constrain cells within defined geometries facilitate quantitative readout of locomotion. Here, we study quasi-one-dimensional cell migration in ring-shaped microlanes. We observe bimodal behavior in form of alternating states of directional migration (run state) and reorientation (rest state). Both states show exponential lifetime distributions with characteristic persistence times, which, together with the cell velocity in the run state, provide a set of parameters that succinctly describe cell motion. By introducing PEGylated barriers of different widths into the lane, we extend this description by quantifying the effects of abrupt changes in substrate chemistry on migrating cells. The transit probability decreases exponentially as a function of barrier width, thus specifying a characteristic penetration depth of the leading lamellipodia. Applying this fingerprint-like characterization of cell motion, we compare different cell lines, and demonstrate that the cancer drug candidate salinomycin affects transit probability and resting time, but not run time or run velocity. Hence, the presented assay allows to assess multiple migration-related parameters, permits detailed characterization of cell motility, and has potential applications in cell biology and advanced drug screening. PMID:27242099

  1. Directing cell migration and organization via nanocrater-patterned cell-repellent interfaces

    PubMed Central

    Jeon, Hojeong; Koo, Sangmo; Reese, Willie Mae; Loskill, Peter; Grigoropoulos, Costas P.; Healy, Kevin E.

    2015-01-01

    Although adhesive interactions between cells and nanostructured interfaces have been studied extensively1–6, there is a paucity of data on how nanostructured interfaces repel cells by directing cell migration and cell-colony organization. Here, by using multiphoton ablation lithography7 to pattern surfaces with nanoscale craters of various aspect ratios and pitches, we show that the surfaces altered the cells’ focal-adhesion size and distribution, thus affecting cell morphology, migration and ultimately localization. We also show that nanocrater pitch can disrupt the formation of mature focal adhesions to favour the migration of cells toward higher-pitched regions, which present increased planar area for the formation of stable focal adhesions. Moreover, by designing surfaces with variable pitch but constant nanocrater dimensions, we were able to create circular and striped cellular patterns. Our surface-patterning approach, which does not involve chemical treatments and can be applied to various materials, represents a simple method to control cell behaviour on surfaces. PMID:26213899

  2. Bioengineering Paradigms for Cell Migration in Confined Microenvironments

    PubMed Central

    Stroka, Kimberly M.; Gu, Zhizhan; Sun, Sean X.; Konstantopoulos, Konstantinos

    2014-01-01

    Cell migration is a fundamental process underlying diverse (patho)physiological phenomena. The classical understanding of the molecular mechanisms of cell migration has been based on in vitro studies on two-dimensional substrates. More recently, mounting evidence from intravital studies has shown that during metastasis, tumor cells must navigate complex microenvironments in vivo, including narrow, pre-existing microtracks created by anatomical structures. It is becoming apparent that unraveling the mechanisms of confined cell migration in this context requires a multi-disciplinary approach through integration of in vivo and in vitro studies, along with sophisticated bioengineering techniques and mathematical modeling. Here, we highlight such an approach that has led to discovery of a new model for cell migration in confined microenvironments (i.e., the Osmotic Engine Model). PMID:24973724

  3. Bioengineering paradigms for cell migration in confined microenvironments.

    PubMed

    Stroka, Kimberly M; Gu, Zhizhan; Sun, Sean X; Konstantopoulos, Konstantinos

    2014-10-01

    Cell migration is a fundamental process underlying diverse (patho)physiological phenomena. The classical understanding of the molecular mechanisms of cell migration has been based on in vitro studies on two-dimensional substrates. More recently, mounting evidence from intravital studies has shown that during metastasis, tumor cells must navigate complex microenvironments in vivo, including narrow, pre-existing microtracks created by anatomical structures. It is becoming apparent that unraveling the mechanisms of confined cell migration in this context requires a multi-disciplinary approach through integration of in vivo and in vitro studies, along with sophisticated bioengineering techniques and mathematical modeling. Here, we highlight such an approach that has led to discovery of a new model for cell migration in confined microenvironments (i.e., the Osmotic Engine Model). PMID:24973724

  4. Migration of adhesive glioma cells: Front propagation and fingering

    NASA Astrophysics Data System (ADS)

    Khain, Evgeniy; Katakowski, Mark; Charteris, Nicholas; Jiang, Feng; Chopp, Michael

    2012-07-01

    We investigate the migration of glioma cells as a front propagation phenomenon both theoretically (by using both discrete lattice modeling and a continuum approach) and experimentally. For small effective strength of cell-cell adhesion q, the front velocity does not depend on q. When q exceeds a critical threshold, a fingeringlike front propagation is observed due to cluster formation in the invasive zone. We show that the experiments correspond to the transient regime, before the regime of front propagation is established. We performed an additional experiment on cell migration. A detailed comparison with experimental observations showed that the theory correctly predicts the maximal migration distance but underestimates the migration of the main mass of cells.

  5. Fundulus deep cells: directional migration in response to epithelial wounding.

    PubMed

    Fink, R D; Trinkaus, J P

    1988-09-01

    During the normal embryogenesis of the killifish Fundulus heteroclitus deep cells migrate in an apparently random fashion throughout the subepithelial space of the yolk sac. These cells migrate by blebbing locomotion, and individual cells show tendencies for persistence in the directionality of their movement. Immediately after the wounding of the yolk sac epithelium (the enveloping layer), these deep cells reorient and migrate directionally toward the site of wound closure. This directional migration results in the aggregation of a large number of cells at the wound site. The response is both rapid and widespread; cells as far away as 800 micron respond as quickly as those nearby, and by 100 min after wounding up to 90% of the blebbing deep cells within this radius have clustered about the wound site. Then, cells begin to disperse, and by 150 min after wounding, it is almost impossible to tell where the wound had been made. Because of the transparency of the Fundulus yolk sac, this phenomenon can be utilized as a model system for observing details of in vivo directional cell movements. Time-lapse video micrography has revealed that the modes, rates, and overall cell morphologies during locomotion are identical for cells migrating in both unwounded and wounded embryos. What is different in the wounded embryos is that a single directionality is imposed upon a large population of cells, resulting in aggregation. Several aspects of the aggregation phenomenon suggest that a possible attractant originating at the wound site may travel through the subepithelial space by diffusion.

  6. Dynamic cell adhesion and migration on nanoscale grooved substrates.

    PubMed

    Lamers, E; te Riet, J; Domanski, M; Luttge, R; Figdor, C G; Gardeniers, J G E; Walboomers, X F; Jansen, J A

    2012-01-01

    Organised nanotopography mimicking the natural extracellular matrix can be used to control morphology, cell motility, and differentiation. However, it is still unknown how specific cell types react with specific patterns. Both initial adhesion and preferential cell migration may be important to initiate and increase cell locomotion and coverage with cells, and thus achieve an enhanced wound healing response around an implantable material. Therefore, the aim of this study was to evaluate how MC3T3-E1 osteoblast initial adhesion and directional migration are influenced by nanogrooves with pitches ranging from 150 nm up to 1000 nm. In this study, we used a multi-patterned substrate with five different groove patterns and a smooth area with either a concentric or radial orientation. Initial cell adhesion measurements after 10 s were performed using atomic force spectroscopy-assisted single-cell force spectroscopy, and demonstrated that nascent cell adhesion was highly induced by a 600 nm pitch and reduced by a 150 nm pitch. Addition of RGD peptide significantly reduced adhesion, indicating that integrins and cell adhesive proteins (e.g. fibronectin or vitronectin) are key factors in specific cell adhesion on nanogrooved substrates. Also, cell migration was highly dependent on the groove pitch; the highest directional migration parallel to the grooves was observed on a 600 nm pitch, whereas a 150 nm pitch restrained directional cell migration. From this study, we conclude that grooves with a pitch of 600 nm may be favourable to enhance fast wound closure, thereby promoting tissue regeneration.

  7. Live Imaging of Border Cell Migration in Drosophila.

    PubMed

    Dai, Wei; Montell, Denise J

    2016-01-01

    Border cells are a cluster of cells that migrate from the anterior tip of the Drosophila egg chamber to the border of the oocyte in stage 9. They serve as a useful model to study collective cell migration in a native tissue environment. Here we describe a protocol for preparing ex vivo egg chamber cultures from transgenic flies expressing fluorescent proteins in the border cells, and using confocal microscopy to take a multi-positional time-lapse movie. We include an image analysis method for tracking border cell cluster dynamics as well as tracking individual cell movements. PMID:27271901

  8. Live Imaging of Border Cell Migration in Drosophila.

    PubMed

    Dai, Wei; Montell, Denise J

    2016-01-01

    Border cells are a cluster of cells that migrate from the anterior tip of the Drosophila egg chamber to the border of the oocyte in stage 9. They serve as a useful model to study collective cell migration in a native tissue environment. Here we describe a protocol for preparing ex vivo egg chamber cultures from transgenic flies expressing fluorescent proteins in the border cells, and using confocal microscopy to take a multi-positional time-lapse movie. We include an image analysis method for tracking border cell cluster dynamics as well as tracking individual cell movements.

  9. The thioredoxin system in breast cancer cell invasion and migration.

    PubMed

    Bhatia, Maneet; McGrath, Kelly L; Di Trapani, Giovanna; Charoentong, Pornpimol; Shah, Fenil; King, Mallory M; Clarke, Frank M; Tonissen, Kathryn F

    2016-08-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration.

  10. The thioredoxin system in breast cancer cell invasion and migration.

    PubMed

    Bhatia, Maneet; McGrath, Kelly L; Di Trapani, Giovanna; Charoentong, Pornpimol; Shah, Fenil; King, Mallory M; Clarke, Frank M; Tonissen, Kathryn F

    2016-08-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration. PMID:26760912

  11. The thioredoxin system in breast cancer cell invasion and migration

    PubMed Central

    Bhatia, Maneet; McGrath, Kelly L.; Di Trapani, Giovanna; Charoentong, Pornpimol; Shah, Fenil; King, Mallory M.; Clarke, Frank M.; Tonissen, Kathryn F.

    2015-01-01

    Metastasis is the most life threatening aspect of breast cancer. It is a multi-step process involving invasion and migration of primary tumor cells with a subsequent colonization of these cells at a secondary location. The aim of the present study was to investigate the role of thioredoxin (Trx1) in the invasion and migration of breast cancer cells and to assess the strength of the association between high levels of Trx1 and thioredoxin reductase (TrxR1) expression with breast cancer patient survival. Our results indicate that the expression of both Trx1 and TrxR1 are statistically significantly increased in breast cancer patient cells compared with paired normal breast tissue from the same patient. Over-expression of Trx1 in MDA-MB-231 breast cancer cell lines enhanced cell invasion in in vitro assays while expression of a redox inactive mutant form of Trx1 (designated 1SS) or the antisense mRNA inhibited cell invasion. Addition of exogenous Trx1 also enhanced cell invasion, while addition of a specific monoclonal antibody that inhibits Trx1 redox function decreased cell invasion. Over-expression of intracellular Trx1 did not increase cell migration but expression of intracellular 1SS inhibited migration. Addition of exogenous Trx1 enhanced cell migration while 1SS had no effect. Treatment with auranofin inhibited TrxR activity, cell migration and clonogenic activity of MDA-MB-231 cells, while increasing reactive oxygen species (ROS) levels. Analysis of 25 independent cohorts with 5910 patients showed that Trx1 and TrxR1 were both associated with a poor patient prognosis in terms of overall survival, distant metastasis free survival and disease free survival. Therefore, targeting the Trx system with auranofin or other specific inhibitors may provide improved breast cancer patient outcomes through inhibition of cancer invasion and migration. PMID:26760912

  12. Collective dynamics of cell migration and cell rearrangements

    NASA Astrophysics Data System (ADS)

    Kabla, Alexandre

    Understanding multicellular processes such as embryo development or cancer metastasis requires to decipher the contributions of local cell autonomous behaviours and long range interactions with the tissue environment. A key question in this context concerns the emergence of large scale coordination in cell behaviours, a requirement for collective cell migration or convergent extension. I will present a few examples where physical and mechanical aspects play a significant role in driving tissue scale dynamics.

  1. Cerium migration during PEM fuel cell assembly and operation

    SciTech Connect

    Baker, Andrew M.; Torraco, Dennis; Judge, Elizabeth J.; Spernjak, Dusan; Mukundan, Rangachary; Borup, Rod L.; Advani, Suresh G.; Prasad, Ajay K.

    2015-09-14

    Cerium migration between PEM fuel cell components is influenced by potential-driven mobility, ionic diffusion, and gradients in water content. These factors were investigated in ex situ experiments and in operating fuel cells. Potential-induced migration was measured ex situ in hydrated window cells. Cerium-containing MEAs were also fabricated and tested under ASTs. MEA disassembly and subsequent XRF analysis were used to observe rapid cerium migration during cell assembly and operation. During MEA hot pressing, humidification, and low RH operation at OCV, ionic diffusion causes uniform migration from the membrane into the catalyst layers. During high RH operation at OCV, in-plane cerium gradients arise due to variations in water content. These gradients may diminish the scavenging efficacy of cerium by reducing its proximity to generated radicals.

  2. Phosphorylation of actopaxin regulates cell spreading and migration

    PubMed Central

    Clarke, Dominic M.; Brown, Michael C.; LaLonde, David P.; Turner, Christopher E.

    2004-01-01

    Actopaxin is an actin and paxillin binding protein that localizes to focal adhesions. It regulates cell spreading and is phosphorylated during mitosis. Herein, we identify a role for actopaxin phosphorylation in cell spreading and migration. Stable clones of U2OS cells expressing actopaxin wild-type (WT), nonphosphorylatable, and phosphomimetic mutants were developed to evaluate actopaxin function. All proteins targeted to focal adhesions, however the nonphosphorylatable mutant inhibited spreading whereas the phosphomimetic mutant cells spread more efficiently than WT cells. Endogenous and WT actopaxin, but not the nonphosphorylatable mutant, were phosphorylated in vivo during cell adhesion/spreading. Expression of the nonphosphorylatable actopaxin mutant significantly reduced cell migration, whereas expression of the phosphomimetic increased cell migration in scrape wound and Boyden chamber migration assays. In vitro kinase assays demonstrate that extracellular signal-regulated protein kinase phosphorylates actopaxin, and treatment of U2OS cells with the MEK1 inhibitor UO126 inhibited adhesion-induced phosphorylation of actopaxin and also inhibited cell migration. PMID:15353548

  3. Interior decoration: tropomyosin in actin dynamics and cell migration.

    PubMed

    Lees, Justin G; Bach, Cuc T T; O'Neill, Geraldine M

    2011-01-01

    Cell migration and invasion requires the precise temporal and spatial orchestration of a variety of biological processes. Filaments of polymerized actin are critical players in these diverse processes, including the regulation of cell anchorage points (both cell-cell and cell-extracellular matrix), the uptake and delivery of molecules via endocytic pathways and the generation of force for both membrane protrusion and retraction. How the actin filaments are specialized for each of these discrete functions is yet to be comprehensively elucidated. The cytoskeletal tropomyosins are a family of actin associating proteins that form head-to-tail polymers which lay in the major groove of polymerized actin filaments. In the present review we summarize the emerging isoform-specific functions of tropomyosins in cell migration and invasion and discuss their potential roles in the specialization of actin filaments for the diverse cellular processes that together regulate cell migration and invasion.

  4. Estrogen Stimulation of Cell Migration Involves Multiple Signaling Pathway Interactions

    PubMed Central

    Li, Yan; Wang, Ji-Ping; Santen, Richard J.; Kim, Tae-Hyun; Park, Hoyong; Fan, Ping; Yue, Wei

    2010-01-01

    Hormone-dependent breast cancers respond to inhibitors of estrogen synthesis or action with tumor regression and with a reduction of new metastases. The mechanisms underlying the effects of estrogen on metastasis likely differ from those on tumor regression. Cell migration is a key first step in the metastatic process. Based on our prior work and other published data, we designed and tested a working model that suggested that estrogen receptor α, epidermal growth factor receptor, focal adhesion kinase (FAK), paxillin, phosphatidylinositol 3 kinase, p60 Src tyrosine kinase (c-Src), c-Jun N-terminal kinase, and MAPK interact to facilitate estradiol (E2)-induced cell migration. Accordingly, we examined the effect of E2 on activation of these pathways and demonstrated mechanistic effects by blocking each component and assessing cell migration as a biologic endpoint. Initial studies validated a robust cell migration assay characterized by highly reproducible, dose-dependent responses to E2. Examining various mechanisms involved in migration, we showed that E2 induced activation of c-Src, FAK, and paxillin with early peaks within 5–30 min and later peaks at 24 h. ERK and protein kinase B phosphorylation exhibited only early peaks. Blockade of various steps in these signaling pathways with use of small interfering RNA or specific inhibitors demonstrated mechanistic effects of these signaling molecules on cell migration. Our results suggest that the effects of E2 on cell migration involve multiple, interacting signaling pathways. Important effects are mediated by the MAPK, phosphatidylinositol 3 kinase, and c-Jun N-terminal kinase pathways and use FAK, paxillin, and c-Src for activation. Each pathway represents a potential target for blocking cell migration and metastasis of breast cancer cells. PMID:20861240

  5. Displacement measurement of the depth migration of transparent cells

    SciTech Connect

    Yoshida, Makoto; Ishimaru, Ichirou; Ishizaki, Katsumi; Yasokawa, Toshiki; Kuriyama, Shigeki; Masaki, Tsutomu; Nakai, Seiji; Takegawa, Kaoru; Tanaka, Naoyuki

    2006-12-11

    This letter reports a method for displacement measurement of the depth migration of transparent cells. This proposed optical spatial filtering method allows visualization of the transparent cells and determination of depth migration as a horizontal displacement positive or negative first order diffracted light on the detector surface. When the sample is displaced upward or downward from the focal plane, first and negative first order diffracted light form images at a different point as a light circle. The coordinates of these two light circles on the detector surface change places when the displacement of depth migration moves to the opposite direction.

  6. Mast cell heparin stimulates migration of capillary endothelial cells in vitro

    PubMed Central

    1980-01-01

    Migration of capillary endothelial cells is an important component of angiogenesis in vivo. Increased numbers of mast cells have been associated with several types of angiogenesis. We have used a quantitative assay in vitro to demonstrate that mast cells release a factor that significantly increases bovine capillary endothelial cell migration. The factor is present in medium conditioned by mast cells as well as lysates of mast cells. The stimulatory effect of mast cells on migration is specific for capillary endothelial cells. Furthermore, mast cells have no mitogenic activity for capillary endothelial cells. Of all the secretory products of mast cells tested, only heparin stimulated capillary endothelial cell migration in vitro. Heparin preparations from a variety of sources stimulated capillary endothelial cell migration to the same degree but did not stimulate migration of several other cell types. The migration activity of heparin and mast cell conditioned medium was blocked by specific antagonists of heparin (protamine and heparinase), but not by chondroitinase ABC. The migration activity of mast cell conditioned medium was resistant to heat (100 degrees C) and incubation with proteolytic enzymes. These results suggest that the role of mast cells in angiogenesis may be to enhance migration of the endothelial cells of growing capillaries. PMID:7420025

  7. A model for cell density effect on stress fiber alignment and collective directional migration

    NASA Astrophysics Data System (ADS)

    Abeddoust, Mohammad; Shamloo, Amir

    2015-12-01

    In this study, numerical simulation of collective cell migration is presented in order to mimic the group migration of endothelial cells subjected to the concentration gradients of a biochemical factor. The developed 2D model incorporates basic elements of the cell, including both the cell membrane and the cell cytoskeleton, based on a viscoelastic cell mechanic model. Various cell processes—including cell random walk, cell-cell interactions, cell chemotaxis, and cellular cytoskeleton rearrangements—are considered and analyzed in our developed model. After validating the model by using available experimental data, the model is used to investigate various important parameters during collective cell chemotaxis, such as cell density, cytoskeleton organization, stress fiber reorientations, and intracellular forces. The results suggest that increasing the cell density causes the cell-cell interactions to affect the orientation of stress fibers throughout the cytoskeleton and makes the stress fibers more aligned in the direction of the imposed concentration gradient. This improved alignment of the stress fibers correlates with the intensification of the intracellular forces transferred in the gradient direction; this improves the cell group migration. Comparison of the obtained results with available experimental observations of collective chemotaxis of endothelial cells shows an interesting agreement.

  8. A model for cell density effect on stress fiber alignment and collective directional migration.

    PubMed

    Abeddoust, Mohammad; Shamloo, Amir

    2015-12-01

    In this study, numerical simulation of collective cell migration is presented in order to mimic the group migration of endothelial cells subjected to the concentration gradients of a biochemical factor. The developed 2D model incorporates basic elements of the cell, including both the cell membrane and the cell cytoskeleton, based on a viscoelastic cell mechanic model. Various cell processes--including cell random walk, cell-cell interactions, cell chemotaxis, and cellular cytoskeleton rearrangements--are considered and analyzed in our developed model. After validating the model by using available experimental data, the model is used to investigate various important parameters during collective cell chemotaxis, such as cell density, cytoskeleton organization, stress fiber reorientations, and intracellular forces. The results suggest that increasing the cell density causes the cell-cell interactions to affect the orientation of stress fibers throughout the cytoskeleton and makes the stress fibers more aligned in the direction of the imposed concentration gradient. This improved alignment of the stress fibers correlates with the intensification of the intracellular forces transferred in the gradient direction; this improves the cell group migration. Comparison of the obtained results with available experimental observations of collective chemotaxis of endothelial cells shows an interesting agreement. PMID:26717999

  9. Membrane nanowaves in single and collective cell migration.

    PubMed

    Zouani, Omar F; Gocheva, Veronika; Durrieu, Marie-Christine

    2014-01-01

    We report the characterization of three-dimensional membrane waves for migrating single and collective cells and describe their propagation using wide-field optical profiling technique with nanometer resolution. We reveal the existence of small and large membrane waves the amplitudes of which are in the range of ∼ 3-7 nm to ∼ 16-25 nm respectively, through the cell. For migrating single-cells, the amplitude of these waves is about 30 nm near the cell edge. Two or more different directions of propagation of the membrane nanowaves inside the same cell can be observed. After increasing the migration velocity by BMP-2 treatment, only one wave direction of propagation exists with an increase in the average amplitude (more than 80 nm near the cell edge). Furthermore for collective-cell migration, these membrane nanowaves are attenuated on the leader cells and poor transmission of these nanowaves to follower cells was observed. After BMP-2 treatment, the membrane nanowaves are transmitted from the leader cell to several rows of follower cells. Surprisingly, the vast majority of the observed membrane nanowaves is shared between the adjacent cells. These results give a new view on how single and collective-cells modulate their motility. This work has significant implications for the therapeutic use of BMPs for the regeneration of skin tissue. PMID:24846182

  10. Cell migration is another player of the minute virus of mice infection

    SciTech Connect

    Garcin, Pierre O.; Panté, Nelly

    2014-11-15

    The parvovirus minute virus of mice, prototype strain (MVMp), preferentially infects and kills cancer cells. This intrinsic MVMp oncotropism may depend in part on the early stages of MVMp infection. To test this hypothesis, we investigated the early events of MVMp infection in mouse LA9 fibroblasts and a highly invasive mouse mammary tumor cell line derived from polyomavirus middle T antigen-mediated transformation. Using a combination of fluorescence and electron microscopy, we found that various parameters of the cell migration process affect MVMp infection. We show that, after binding to the plasma membrane, MVMp particles rapidly cluster at the leading edge of migrating cells, which exhibit higher levels of MVMp uptake than non-motile cells. Moreover, promoting cell migration on a fibronectin matrix increased MVMp infection, and induction of epithelial–mesenchymal transition allowed MVMp replication in non-permissive epithelial cells. Hence, we propose that cell migration influences the early stages of MVMp infection. - Highlights: • We document early steps of MVMp infection. • We report that a fibronectin matrix promotes MVMp infection. • We show that cellular migration plays a role in MVMp uptake. • We show that epithelial–mesenchymal transition allows MVMp replication.

  11. Energy barriers and cell migration in confluent tissues

    NASA Astrophysics Data System (ADS)

    Bi, Dapeng; Lopez, J. H.; Schwarz, J. M.; Manning, M. Lisa

    2014-03-01

    Biological processes such as embryogensis, tumorigenesis and wound healing require cells to move within a tissue. While the migration of single cells has been extensively studied, it has remained unclear how single cell properties control migration through a confluent tissue. We develop numerical and theoretical models to calculate energy barriers to cell rearrangements, which govern cell motility. In contrast to sheared foams where energy barriers are power-law distributed, energy barriers in tissues are exponentially distributed and depend systematically on the cell's number of neighbors. Using simple extensions of `trap' and `Soft Glassy Rheology' models, we demonstrate that these energy barrier distributions give rise to glassy behavior and use the models to make testable predictions for two-time correlation functions and caging times. We incorporate these ideas into a continuum model that combines glassy rheology with active polarization to better understand collective migration in epithelial sheets.

  12. Laser-photophoretic migration and fractionation of human blood cells.

    PubMed

    Monjushiro, Hideaki; Tanahashi, Yuko; Watarai, Hitoshi

    2013-05-13

    Laser photophoretic migration behavior of human blood cells in saline solution was investigated under the irradiation of Nd:YAG laser beam (532 nm) in the absence and the presence of the flow in a fused silica capillary. Red blood cells (RBC) were migrated faster than white blood cells (WBC) and blood pellets to the direction of propagation of laser light. The observed photophoretic velocity of RBC was about 11 times faster than those of others. This was understood from the larger photophoretic efficiency of RBC than that of WBC, which was simulated based on the Mie scattering theory. Furthermore, it was found that, during the photophoretic migration, RBCs spontaneously orientated parallel to the migration direction so as to reduce the drag force. Finally, it was demonstrated that RBC and WBC were separated in a micro-channel flow system by the laser photophoresis.

  13. Cell migration in confinement: a micro-channel-based assay.

    PubMed

    Heuzé, Mélina L; Collin, Olivier; Terriac, Emmanuel; Lennon-Duménil, Ana-Maria; Piel, Matthieu

    2011-01-01

    This chapter describes a method to study cells migrating in micro-channels, a confining environment of well-defined geometry. This assay is a complement to more complex 3D migration systems and provides several advantages even if it does not recapitulate the full complexity of 3D migration. Important parameters such as degree of adhesion, degree of confinement, mechanical properties, and geometry can be varied independently of each other. The device is fully compatible with almost any type of light microscopy and the simple geometry makes automated analysis very easy to perform, which allows screening strategy. The chapters is divided into five parts describing the design of different types of migration chambers, the fabrication of a mold by photolithography, the assembly of the chamber, the loading of cells, and finally the imaging on live or fixed cells. PMID:21748692

  14. Facile preparation of a photoactivatable surface on a 96-well plate: a versatile and multiplex cell migration assay platform.

    PubMed

    Kamimura, Masao; Scheideler, Olivia; Shimizu, Yoshihisa; Yamamoto, Shota; Yamaguchi, Kazuo; Nakanishi, Jun

    2015-06-01

    reproducibility. Interestingly, the impact of blebbistatin on cell migration was dependent upon the widths of the migrating regions, resulting in both cases of migration acceleration and deceleration. These results clearly demonstrate that the cellular response to certain drugs is highly affected by their migrating geometries. Therefore, the obtained novel photoactivatable 96-well plate serves as a useful high-throughput platform for the identification of drug candidates that have an effect on cell migration behavior.

  15. Mechanics in Mechanosensitivity of Cell Adhesion and its Roles in Cell Migration

    NASA Astrophysics Data System (ADS)

    Zhong, Yuan; He, Shijie; Ji, Baohua

    2012-12-01

    Cells sense and respond to external stimuli and properties of their environment through focal adhesion complexes (FACs) to regulate a broad range of physiological and pathological processes, including cell migration. Currently, the basic principles in mechanics of the mechanosensitivity of cell adhesion and migration have not been fully understood. In this paper, an FEM-based mechano-chemical coupling model is proposed for studying the cell migration behaviors in which the dynamics of stability of FACs and the effect of cell shape on cell traction force distribution are considered. We find that the driving force of cell migration is produced by the competition of stability of cell adhesion between the cell front and cell rear, which consequently controls the speed of cell migration. We show that the rigidity gradient of matrix can bias this competition which allows cell to exhibit a durotaxis behavior, i.e. the larger the gradient, the higher the cell speed.

  16. Gold Nanorods Indirectly Promote Migration of Metastatic Human Breast Cancer Cells in Three-Dimensional Cultures.

    PubMed

    Grzincic, Elissa M; Murphy, Catherine J

    2015-07-28

    Gold nanomaterials are intensively studied for applications in disease detection, diagnosis and therapeutics, and this has motivated considerable research to determine their interaction with biomolecules, cells and cell behaviors. However, few studies look at how nanomaterials alter the extracellular matrix (ECM) and cell-ECM interactions. Nanomaterials in the body would interact with the entire cellular environment, and it is imperative to account for this when studying the impact of nanomaterials on living systems. Furthermore, recent evidence finds that migration rates of cells in 2D can be affected by nanomaterials, and uptake of the nanomaterials is not necessary to exert an effect. In this study, three-dimensional nested type I collagen matrices were utilized as a model ECM to study how gold nanorods affect the migration of MDA-MB-231 human breast cancer cells. Spontaneous cell migration through collagen containing gold nanorods was found to increase with increasing concentrations of gold nanorods, independent of intracellular uptake of the nanorods. Gold nanorods in the collagen matrix were found to alter collagen mechanical properties and structure, molecular diffusion, cellular adhesion, cell morphology, mode of migration and protease expression. Correlation between decreased cellular adhesion and rounded cell morphology and locomotion in nanorod-containing collagen suggests the induction of an amoeboid-like migratory phenotype.

  17. Commensal bacteria promote migration of mast cells into the intestine.

    PubMed

    Kunii, Junichi; Takahashi, Kyoko; Kasakura, Kazumi; Tsuda, Masato; Nakano, Kou; Hosono, Akira; Kaminogawa, Shuichi

    2011-06-01

    Mast cells differentiate from hematopoietic stem cells in the bone marrow and migrate via the circulation to peripheral tissues, where they play a pivotal role in induction of both innate and adaptive immune responses. In this study, the effect of intestinal commensal bacteria on the migration of mast cells into the intestine was investigated. Histochemical analyses showed that germ-free (GF) mice had lower mast cell densities in the small intestine than normal mice. It was also shown that GF mice had lower mast cell proportion out of lamina propria leukocytes in the small intestine and higher mast cell percentages in the blood than normal mice by flow cytometry. These results indicate that migration of mast cells from the blood to the intestine is promoted by intestinal commensal bacteria. In addition, MyD88⁻/⁻ mice had lower densities of intestinal mast cells than CV mice, suggesting that the promotive effect of commensals is, at least in part, TLR-dependent. The ligands of CXC chemokine receptor 2 (CXCR2), which is critical for homing of mast cells to the intestine, were expressed higher in intestinal tissues and in intestinal epithelial cells (IECs) of normal mice than in those of GF or MyD88⁻/⁻ mice. Collectively, it is suggested that commensals promote migration of mast cells into the intestine through the induction of CXCR2 ligands from IECs in a TLR-dependent manner.

  18. Insights into the role of sulfated glycans in cancer cell adhesion and migration through use of branched peptide probe

    PubMed Central

    Brunetti, Jlenia; Depau, Lorenzo; Falciani, Chiara; Gentile, Mariangela; Mandarini, Elisabetta; Riolo, Giulia; Lupetti, Pietro; Pini, Alessandro; Bracci, Luisa

    2016-01-01

    The tetra-branched peptide NT4 selectively binds to different human cancer cells and tissues. NT4 specifically binds to sulfated glycosaminoglycans on cancer cell membranes. Since sulfated glycosaminoglycans are involved in cancer cell interaction with the extracellular matrix, we evaluated the effect of NT4 on cancer cell adhesion and migration. We demonstrated here that the branched peptide NT4 binds sulfated glycosaminoglycans with high affinity and with preferential binding to heparan sulfate. NT4 inhibits cancer cell adhesion and migration on different proteins, without modifying cancer cell morphology or their ability to produce protrusions, but dramatically affecting the directionality and polarity of cell movement. Results obtained by taking advantage of the selective targeting of glycosaminoglycans chains by NT4, provide insights into the role of heparan sulfate proteoglycans in cancer cell adhesion and migration and suggest a determinant role of sulfated glycosaminoglycans in the control of cancer cell directional migration. PMID:27255651

  19. Magnetic micro-device for manipulating PC12 cell migration and organization.

    PubMed

    Alon, N; Havdala, T; Skaat, H; Baranes, K; Marcus, M; Levy, I; Margel, S; Sharoni, A; Shefi, O

    2015-05-01

    Directing neuronal migration and growth has an important impact on potential post traumatic therapies. Magnetic manipulation is an advantageous method for remotely guiding cells. In the present study, we have generated highly localized magnetic fields with controllable magnetic flux densities to manipulate neuron-like cell migration and organization at the microscale level. We designed and fabricated a unique miniaturized magnetic device composed of an array of rectangular ferromagnetic bars made of permalloy (Ni80Fe20), sputter-deposited onto glass substrates. The asymmetric shape of the magnets enables one to design a magnetic landscape with high flux densities at the poles. Iron oxide nanoparticles were introduced into PC12 cells, making the cells magnetically sensitive. First, we manipulated the cells by applying an external magnetic field. The magnetic force was strong enough to direct PC12 cell migration in culture. Based on time lapse observations, we analysed the movement of the cells and estimated the amount of MNPs per cell. We plated the uploaded cells on the micro-patterned magnetic device. The cells migrated towards the high magnetic flux zones and aggregated at the edges of the patterned magnets, corroborating that the cells with magnetic nanoparticles are indeed affected by the micro-magnets and attracted to the bars' magnetic poles. Our study presents an emerging method for the generation of pre-programmed magnetic micro-'hot spots' to locate and direct cellular growth, setting the stage for implanted magnetic devices. PMID:25792133

  20. Three-Dimensional Numerical Model of Cell Morphology during Migration in Multi-Signaling Substrates

    PubMed Central

    Mousavi, Seyed Jamaleddin; Hamdy Doweidar, Mohamed

    2015-01-01

    Cell Migration associated with cell shape changes are of central importance in many biological processes ranging from morphogenesis to metastatic cancer cells. Cell movement is a result of cyclic changes of cell morphology due to effective forces on cell body, leading to periodic fluctuations of the cell length and cell membrane area. It is well-known that the cell can be guided by different effective stimuli such as mechanotaxis, thermotaxis, chemotaxis and/or electrotaxis. Regulation of intracellular mechanics and cell’s physical interaction with its substrate rely on control of cell shape during cell migration. In this notion, it is essential to understand how each natural or external stimulus may affect the cell behavior. Therefore, a three-dimensional (3D) computational model is here developed to analyze a free mode of cell shape changes during migration in a multi-signaling micro-environment. This model is based on previous models that are presented by the same authors to study cell migration with a constant spherical cell shape in a multi-signaling substrates and mechanotaxis effect on cell morphology. Using the finite element discrete methodology, the cell is represented by a group of finite elements. The cell motion is modeled by equilibrium of effective forces on cell body such as traction, protrusion, electrostatic and drag forces, where the cell traction force is a function of the cell internal deformations. To study cell behavior in the presence of different stimuli, the model has been employed in different numerical cases. Our findings, which are qualitatively consistent with well-known related experimental observations, indicate that adding a new stimulus to the cell substrate pushes the cell to migrate more directionally in more elongated form towards the more effective stimuli. For instance, the presence of thermotaxis, chemotaxis and electrotaxis can further move the cell centroid towards the corresponding stimulus, respectively, diminishing the

  1. Cell speed, persistence and information transmission during signal relay and collective migration.

    PubMed

    McCann, Colin P; Kriebel, Paul W; Parent, Carole A; Losert, Wolfgang

    2010-05-15

    Collective migration is a key feature of the social amoebae Dictyostelium discoideum, where the binding of chemoattractants leads to the production and secretion of additional chemoattractant and the relay of the signal to neighboring cells. This then guides cells to migrate collectively in a head-to-tail fashion. We used mutants that were defective in signal relay to elucidate which quantitative metrics of cell migration are most strongly affected by signal relay and collective motion. We show that neither signal relay nor collective motion markedly impact the speed of cell migration. Cells maintained a preferred overall direction of motion for several minutes with similar persistence, regardless of whether or not they were attracted to moving neighbors, moving collectively in contact with their neighbors, or simply following a fixed exogenous signal. We quantitatively establish that signal relay not only increases the number of cells that respond to a chemotactic signal, but most remarkably, also transmits information about the location of the source accurately over large distances, independently of the strength of the exogenous signal. We envision that signal relay has a similar key role in the migration of a variety of chemotaxing mammalian cells that can relay chemoattractant signals. PMID:20427323

  2. Nuclear stiffening inhibits migration of invasive melanoma cells

    PubMed Central

    Ribeiro, Alexandre J.S.; Khanna, Payal; Sukumar, Aishwarya; Dong, Cheng; Dahl, Kris Noel

    2014-01-01

    During metastasis, melanoma cells must be sufficiently deformable to squeeze through extracellular barriers with small pore sizes. We visualize and quantify deformability of single cells using micropipette aspiration and examine the migration potential of a population of melanoma cells using a flow migration apparatus. We artificially stiffen the nucleus with recombinant overexpression of Δ50 lamin A, which is found in patients with Hutchison Gilford progeria syndrome and in aged individuals. Melanoma cells, both WM35 and Lu1205, both show reduced nuclear deformability and reduced cell invasion with the expression of Δ50 lamin A. These studies suggest that cellular aging including expression of Δ50 lamin A and nuclear stiffening may reduce the potential for metastatic cancer migration. Thus, the pathway of cancer metastasis may be kept in check by mechanical factors in addition to known chemical pathway regulation. PMID:25544862

  3. Mathematical Modeling of Eukaryotic Cell Migration: Insights Beyond Experiments

    PubMed Central

    Danuser, Gaudenz; Allard, Jun; Mogilner, Alex

    2014-01-01

    A migrating cell is a molecular machine made of tens of thousands of short-lived and interacting parts. Understanding migration means understanding the self-organization of these parts into a system of functional units. This task is one of tackling complexity: First, the system integrates numerous chemical and mechanical component processes. Second, these processes are connected in feedback interactions and over a large range of spatial and temporal scales. Third, many processes are stochastic, which leads to heterogeneous migration behaviors. Early on in the research of cell migration it became evident that this complexity exceeds human intuition. Thus, the cell migration community has led the charge to build mathematical models that could integrate the diverse experimental observations and measurements in consistent frameworks, first in conceptual and more recently in molecularly explicit models. The main goal of this review is to sift through a series of important conceptual and explicit mathematical models of cell migration and to evaluate their contribution to the field in their ability to integrate critical experimental data. PMID:23909278

  4. Cell collectivity regulation within migrating cell cluster during Kupffer's vesicle formation in zebrafish

    PubMed Central

    Matsui, Takaaki; Ishikawa, Hiroshi; Bessho, Yasumasa

    2015-01-01

    Although cell adhesion is thought to fasten cells tightly, cells that adhere to each other can migrate directionally. This group behavior, called “collective cell migration,” is observed during normal development, wound healing, and cancer invasion. Loss-of-function of cell adhesion molecules in several model systems of collective cell migration results in delay or inhibition of migration of cell groups but does not lead to dissociation of the cell groups, suggesting that mechanisms of cells staying assembled as a single cell cluster, termed as “cell collectivity,” remain largely unknown. During the formation of Kupffer's vesicle (KV, an organ of laterality in zebrafish), KV progenitors form a cluster and migrate together toward the vegetal pole. Importantly, in this model system of collective cell migration, knockdown of cell adhesion molecules or signal components leads to failure of cell collectivity. In this review, we summarize recent findings in cell collectivity regulation during collective migration of KV progenitor cells and describe our current understanding of how cell collectivity is regulated during collective cell migration. PMID:26000276

  5. Phototherapy promotes cell migration in the presence of hydroxyurea.

    PubMed

    Zungu, I L; Mbene, A B; Hawkins Evans, D H; Houreld, N N; Abrahamse, H

    2009-03-01

    Phototherapy has been shown to cause an increase in cell proliferation and migration. This study focused on viability (trypan blue), proliferation [sodium 3'-(1-(phenylaminocarbonyl)-3,4-tetrazolium)-bis(4-methoxy-6-nitro)-benzene sulphonic acid hydrate (XTT) and adenosine triphosphate (ATP)] and migration of WS1 cells following irradiation in the presence of hydroxyurea (HU), which is an inhibitor of proliferation. Wounded cells were irradiated on days 1 and 4 with a fluence of 5 J/cm(2) with a helium-neon (He-Ne) laser at 632.8 nm. After a repair time of 24 h, cellular responses were assessed. Wounded irradiated cells without HU showed an increase in cell viability and proliferation, which was confirmed by complete wound closure by day 4. Although wounded irradiated cells treated with 5 mM HU showed incomplete wound closure, these cells showed increased migration compared with that of control cells. This study showed that laser irradiation using an He-Ne laser with a fluence of 5 J/cm(2) stimulates cell viability. The HU results confirmed that laser irradiation promotes cell migration and proliferation. PMID:18214574

  6. Protrusive waves guide 3D cell migration along nanofibers.

    PubMed

    Guetta-Terrier, Charlotte; Monzo, Pascale; Zhu, Jie; Long, Hongyan; Venkatraman, Lakshmi; Zhou, Yue; Wang, PeiPei; Chew, Sing Yian; Mogilner, Alexander; Ladoux, Benoit; Gauthier, Nils C

    2015-11-01

    In vivo, cells migrate on complex three-dimensional (3D) fibrous matrices, which has made investigation of the key molecular and physical mechanisms that drive cell migration difficult. Using reductionist approaches based on 3D electrospun fibers, we report for various cell types that single-cell migration along fibronectin-coated nanofibers is associated with lateral actin-based waves. These cyclical waves have a fin-like shape and propagate up to several hundred micrometers from the cell body, extending the leading edge and promoting highly persistent directional movement. Cells generate these waves through balanced activation of the Rac1/N-WASP/Arp2/3 and Rho/formins pathways. The waves originate from one major adhesion site at leading end of the cell body, which is linked through actomyosin contractility to another site at the back of the cell, allowing force generation, matrix deformation and cell translocation. By combining experimental and modeling data, we demonstrate that cell migration in a fibrous environment requires the formation and propagation of dynamic, actin based fin-like protrusions.

  7. Protrusive waves guide 3D cell migration along nanofibers

    PubMed Central

    Guetta-Terrier, Charlotte; Monzo, Pascale; Zhu, Jie; Long, Hongyan; Venkatraman, Lakshmi; Zhou, Yue; Wang, PeiPei; Chew, Sing Yian; Mogilner, Alexander

    2015-01-01

    In vivo, cells migrate on complex three-dimensional (3D) fibrous matrices, which has made investigation of the key molecular and physical mechanisms that drive cell migration difficult. Using reductionist approaches based on 3D electrospun fibers, we report for various cell types that single-cell migration along fibronectin-coated nanofibers is associated with lateral actin-based waves. These cyclical waves have a fin-like shape and propagate up to several hundred micrometers from the cell body, extending the leading edge and promoting highly persistent directional movement. Cells generate these waves through balanced activation of the Rac1/N-WASP/Arp2/3 and Rho/formins pathways. The waves originate from one major adhesion site at leading end of the cell body, which is linked through actomyosin contractility to another site at the back of the cell, allowing force generation, matrix deformation and cell translocation. By combining experimental and modeling data, we demonstrate that cell migration in a fibrous environment requires the formation and propagation of dynamic, actin based fin-like protrusions. PMID:26553933

  8. Molecular mechanisms underlying progesterone-enhanced breast cancer cell migration

    PubMed Central

    Wang, Hui-Chen; Lee, Wen-Sen

    2016-01-01

    Progesterone (P4) was demonstrated to inhibit migration in vascular smooth muscle cells (VSMCs), but to enhance migration in T47D breast cancer cells. To investigate the mechanism responsible for this switch in P4 action, we examined the signaling pathway responsible for the P4-induced migration enhancement in breast cancer cell lines, T47D and MCF-7. Here, we demonstrated that P4 activated the cSrc/AKT signaling pathway, subsequently inducing RSK1 activation, which in turn increased phosphorylation of p27 at T198 and formation of the p27pT198-RhoA complex in the cytosol, thereby preventing RhoA degradation, and eventually enhanced migration in T47D cells. These findings were confirmed in the P4-treated MCF-7. Comparing the P4-induced molecular events in between breast cancer cells and VSMCs, we found that P4 increased p27 phosphorylation at T198 in breast cancer cells through RSK1 activation, while P4 increased p27 phosphorlation at Ser10 in VSMCs through KIS activation. P27pT198 formed the complex with RhoA and prevented RhoA degradation in T47D cells, whereas p-p27Ser10 formed the complex with RhoA and caused RhoA degradation in VSMCs. The results of this study highlight the molecular mechanism underlying P4-enhanced breast cancer cell migration, and suggest that RSK1 activation is responsible for the P4-induced migration enhancement in breast cancer cells. PMID:27510838

  9. Multidisciplinary approaches to understanding collective cell migration in developmental biology.

    PubMed

    Schumacher, Linus J; Kulesa, Paul M; McLennan, Rebecca; Baker, Ruth E; Maini, Philip K

    2016-06-01

    Mathematical models are becoming increasingly integrated with experimental efforts in the study of biological systems. Collective cell migration in developmental biology is a particularly fruitful application area for the development of theoretical models to predict the behaviour of complex multicellular systems with many interacting parts. In this context, mathematical models provide a tool to assess the consistency of experimental observations with testable mechanistic hypotheses. In this review, we showcase examples from recent years of multidisciplinary investigations of neural crest cell migration. The neural crest model system has been used to study how collective migration of cell populations is shaped by cell-cell interactions, cell-environmental interactions and heterogeneity between cells. The wide range of emergent behaviours exhibited by neural crest cells in different embryonal locations and in different organisms helps us chart out the spectrum of collective cell migration. At the same time, this diversity in migratory characteristics highlights the need to reconcile or unify the array of currently hypothesized mechanisms through the next generation of experimental data and generalized theoretical descriptions. PMID:27278647

  10. PRK1/PKN1 controls migration and metastasis of androgen-independent prostate cancer cells.

    PubMed

    Jilg, Cordula A; Ketscher, Anett; Metzger, Eric; Hummel, Barbara; Willmann, Dominica; Rüsseler, Vanessa; Drendel, Vanessa; Imhof, Axel; Jung, Manfred; Franz, Henriette; Hölz, Stefanie; Krönig, Malte; Müller, Judith M; Schüle, Roland

    2014-12-30

    The major threat in prostate cancer is the occurrence of metastases in androgen-independent tumor stage, for which no causative cure is available. Here we show that metastatic behavior of androgen-independent prostate tumor cells requires the protein-kinase-C-related kinase (PRK1/PKN1) in vitro and in vivo. PRK1 regulates cell migration and gene expression through its kinase activity, but does not affect cell proliferation. Transcriptome and interactome analyses uncover that PRK1 regulates expression of migration-relevant genes by interacting with the scaffold protein sperm-associated antigen 9 (SPAG9/JIP4). SPAG9 and PRK1 colocalize in human cancer tissue and are required for p38-phosphorylation and cell migration. Accordingly, depletion of either ETS domain-containing protein Elk-1 (ELK1), an effector of p38-signalling or p38 depletion hinders cell migration and changes expression of migration-relevant genes as observed upon PRK1-depletion. Importantly, a PRK1 inhibitor prevents metastases in mice, showing that the PRK1-pathway is a promising target to hamper prostate cancer metastases in vivo. Here we describe a novel mechanism controlling the metastatic behavior of PCa cells and identify PRK1 as a promising therapeutic target to treat androgen-independent metastatic prostate cancer. PMID:25504435

  11. Arachidonic Acid Randomizes Endothelial Cell Motion and Regulates Adhesion and Migration

    PubMed Central

    Rossen, Ninna Struck; Hansen, Anker Jon; Selhuber-Unkel, Christine; Oddershede, Lene Broeng

    2011-01-01

    Cell adhesion and migration are essential for the evolution, organization, and repair of living organisms. An example of a combination of these processes is the formation of new blood vessels (angiogenesis), which is mediated by a directed migration and adhesion of endothelial cells (ECs). Angiogenesis is an essential part of wound healing and a prerequisite of cancerous tumor growth. We investigated the effect of the amphiphilic compound arachidonic acid (AA) on EC adhesion and migration by combining live cell imaging with biophysical analysis methods. AA significantly influenced both EC adhesion and migration, in either a stimulating or inhibiting fashion depending on AA concentration. The temporal evolution of cell adhesion area was well described by a two-phase model. In the first phase, the spreading dynamics were independent of AA concentration. In the latter phase, the spreading dynamics increased at low AA concentrations and decreased at high AA concentrations. AA also affected EC migration; though the instantaneous speed of individual cells remained independent of AA concentration, the individual cells lost their sense of direction upon addition of AA, thus giving rise to an overall decrease in the collective motion of a confluent EC monolayer into vacant space. Addition of AA also caused ECs to become more elongated, this possibly being related to incorporation of AA in the EC membrane thus mediating a change in the viscosity of the membrane. Hence, AA is a promising non-receptor specific regulator of wound healing and angiogenesis. PMID:21966453

  12. PRK1/PKN1 controls migration and metastasis of androgen-independent prostate cancer cells.

    PubMed

    Jilg, Cordula A; Ketscher, Anett; Metzger, Eric; Hummel, Barbara; Willmann, Dominica; Rüsseler, Vanessa; Drendel, Vanessa; Imhof, Axel; Jung, Manfred; Franz, Henriette; Hölz, Stefanie; Krönig, Malte; Müller, Judith M; Schüle, Roland

    2014-12-30

    The major threat in prostate cancer is the occurrence of metastases in androgen-independent tumor stage, for which no causative cure is available. Here we show that metastatic behavior of androgen-independent prostate tumor cells requires the protein-kinase-C-related kinase (PRK1/PKN1) in vitro and in vivo. PRK1 regulates cell migration and gene expression through its kinase activity, but does not affect cell proliferation. Transcriptome and interactome analyses uncover that PRK1 regulates expression of migration-relevant genes by interacting with the scaffold protein sperm-associated antigen 9 (SPAG9/JIP4). SPAG9 and PRK1 colocalize in human cancer tissue and are required for p38-phosphorylation and cell migration. Accordingly, depletion of either ETS domain-containing protein Elk-1 (ELK1), an effector of p38-signalling or p38 depletion hinders cell migration and changes expression of migration-relevant genes as observed upon PRK1-depletion. Importantly, a PRK1 inhibitor prevents metastases in mice, showing that the PRK1-pathway is a promising target to hamper prostate cancer metastases in vivo. Here we describe a novel mechanism controlling the metastatic behavior of PCa cells and identify PRK1 as a promising therapeutic target to treat androgen-independent metastatic prostate cancer.

  13. PRK1/PKN1 controls migration and metastasis of androgen-independent prostate cancer cells

    PubMed Central

    Jilg, Cordula A.; Ketscher, Anett; Metzger, Eric; Hummel, Barbara; Willmann, Dominica; Rüsseler, Vanessa; Drendel, Vanessa; Imhof, Axel; Jung, Manfred; Franz, Henriette; Hölz, Stefanie; Krönig, Malte; Müller, Judith M.; Schüle, Roland

    2014-01-01

    The major threat in prostate cancer is the occurrence of metastases in androgen-independent tumor stage, for which no causative cure is available. Here we show that metastatic behavior of androgen-independent prostate tumor cells requires the protein-kinase-C-related kinase (PRK1/PKN1) in vitro and in vivo. PRK1 regulates cell migration and gene expression through its kinase activity, but does not affect cell proliferation. Transcriptome and interactome analyses uncover that PRK1 regulates expression of migration-relevant genes by interacting with the scaffold protein sperm-associated antigen 9 (SPAG9/JIP4). SPAG9 and PRK1 colocalize in human cancer tissue and are required for p38-phosphorylation and cell migration. Accordingly, depletion of either ETS domain-containing protein Elk-1 (ELK1), an effector of p38-signalling or p38 depletion hinders cell migration and changes expression of migration-relevant genes as observed upon PRK1-depletion. Importantly, a PRK1 inhibitor prevents metastases in mice, showing that the PRK1-pathway is a promising target to hamper prostate cancer metastases in vivo. Statement of significance Here we describe a novel mechanism controlling the metastatic behavior of PCa cells and identify PRK1 as a promising therapeutic target to treat androgen-independent metastatic prostate cancer. PMID:25504435

  14. Cerium migration during PEM fuel cell accelerated stress testing

    SciTech Connect

    Baker, Andrew M.; Mukundan, Rangachary; Borup, Rodney L.; Spernjak, Dusan; Judge, Elizabeth J.; Advani, Suresh G.; Prasad, Ajay K.

    2016-01-01

    Cerium is a radical scavenger which improves polymer electrolyte membrane (PEM) fuel cell durability. During operation, however, cerium rapidly migrates in the PEM and into the catalyst layers (CLs). In this work, membrane electrode assemblies (MEAs) were subjected to accelerated stress tests (ASTs) under different humidity conditions. Cerium migration was characterized in the MEAs after ASTs using X-ray fluorescence. During fully humidified operation, water flux from cell inlet to outlet generated in-plane cerium gradients. Conversely, cerium profiles were flat during low humidity operation, where in-plane water flux was negligible, however, migration from the PEM into the CLs was enhanced. Humidity cycling resulted in both in-plane cerium gradients due to water flux during the hydration component of the cycle, and significant migration into the CLs. Fluoride and cerium emissions into effluent cell waters were measured during ASTs and correlated, which signifies that ionomer degradation products serve as possible counter-ions for cerium emissions. Fluoride emission rates were also correlated to final PEM cerium contents, which indicates that PEM degradation and cerium migration are coupled. Lastly, it is proposed that cerium migrates from the PEM due to humidification conditions and degradation, and is subsequently stabilized in the CLs by carbon catalyst supports.

  15. Cerium migration during PEM fuel cell accelerated stress testing

    DOE PAGES

    Baker, Andrew M.; Mukundan, Rangachary; Borup, Rodney L.; Spernjak, Dusan; Judge, Elizabeth J.; Advani, Suresh G.; Prasad, Ajay K.

    2016-01-01

    Cerium is a radical scavenger which improves polymer electrolyte membrane (PEM) fuel cell durability. During operation, however, cerium rapidly migrates in the PEM and into the catalyst layers (CLs). In this work, membrane electrode assemblies (MEAs) were subjected to accelerated stress tests (ASTs) under different humidity conditions. Cerium migration was characterized in the MEAs after ASTs using X-ray fluorescence. During fully humidified operation, water flux from cell inlet to outlet generated in-plane cerium gradients. Conversely, cerium profiles were flat during low humidity operation, where in-plane water flux was negligible, however, migration from the PEM into the CLs was enhanced. Humiditymore » cycling resulted in both in-plane cerium gradients due to water flux during the hydration component of the cycle, and significant migration into the CLs. Fluoride and cerium emissions into effluent cell waters were measured during ASTs and correlated, which signifies that ionomer degradation products serve as possible counter-ions for cerium emissions. Fluoride emission rates were also correlated to final PEM cerium contents, which indicates that PEM degradation and cerium migration are coupled. Lastly, it is proposed that cerium migrates from the PEM due to humidification conditions and degradation, and is subsequently stabilized in the CLs by carbon catalyst supports.« less

  16. Role of urokinase and its receptor in basal and stimulated colonic epithelial cell migration in vitro

    PubMed Central

    Wilson, A; Gibson, P

    2000-01-01

    BACKGROUND—Migration of colonic epithelial cells is important for mucosal repair following injury. The urokinase (u-PA) system regulates migration in other cell types.
AIM—To examine the role of u-PA and its receptor (u-PAR) in colonic epithelial cell migration.
METHODS—Migration was assessed over 24 hours in circular wounds made in confluent monolayers of LIM1215 and Caco-2 human colon cancer cells. The function of u-PA and u-PAR was ablated with antisense oligonucleotides to block expression, with synthetic u-PA peptides to block interaction, and with aprotinin to block u-PA mediated proteolysis.
RESULTS—Migration was stimulated two to threefold by exogenous u-PA, an effect dependent on u-PAR binding but independent of u-PA mediated mitogenesis and proteolysis. Expression of u-PA and u-PAR was inhibited by 80% by the appropriate antisense oligonucleotide. Basal migration and the motogenic effects of butyrate, epidermal growth factor, and phorbol-12-myristate-13-acetate were suppressed by the u-PAR antisense oligonucleotide (40-60%) but were at best minimally affected following inhibition of u-PA expression and binding. 
CONCLUSIONS—In an in vitro model of wounded colonic epithelium, u-PAR promotes cell migration through mechanisms that are not exclusively dependent on u-PA binding. Therefore, u-PA and u-PAR may contribute to colonic mucosal repair in vivo.


Keywords: colon; migration; urokinase; urokinase receptor; epidermal growth factor; butyrate; protein kinase C PMID:10861271

  17. Junctional communication is induced in migrating capillary endothelial cells

    PubMed Central

    1989-01-01

    Using an in vitro model in which a confluent monolayer of capillary endothelial cells is mechanically wounded, gap junction-mediated intercellular communication has been studied by loading the cells with the fluorescent dye, Lucifer Yellow. Approximately 40-50% of the cells in a nonwounded confluent monolayer were coupled in groups of four to five cells (basal level). Basal levels of communication were also observed in sparse and preconfluent cultures, but were reduced in postconfluent monolayers. 30 min after wounding, coupling was markedly reduced between cells lining the wound. Communication at the wound was partially reestablished by 2 h, exceeded basal levels after 6 h and reached a maximum after 24 h, at which stage approximately 90% of the cells were coupled in groups of six to seven cells. When the wound had closed (after 8 d), the increase in communication was no longer observed. Induction of wound-associated communication was unaffected by exposure of the cells to the DNA synthesis inhibitor mitomycin C, but was prevented by the protein synthesis inhibitor, cycloheximide. The induction of wound-associated communication was also inhibited when migration was prevented by placing the cells immediately after wounding at 22 degrees C or after exposure to cytochalasin D, suggesting that the increase in communication is dependent on cells migrating into the wound area. In contrast, migration was not prevented when coupling was blocked by exposure of the cells to retinoic acid, although this agent did disrupt the characteristic sheet-like pattern of migration typically seen during endothelial repair. These results suggest that junctional communication may play an important role in wound repair, possibly by coordinating capillary endothelial cell migration. PMID:2592412

  18. Cellular Polarization and Contractility in Collective Cell Migration

    NASA Astrophysics Data System (ADS)

    Utuje, Kazage J. Christophe; Notbohm, Jacob; Banerjee, Shiladitya; Gweon, Bomi; Jang, Hwanseok; Park, Yongdoo; Shin, Jennifer; Butler, James P.; Fredberg, Jeffrey J.; Marchetti, M. Cristina

    Collective cell migration drives many biological processes such as metastasis, morphogenesis and wound healing. These coordinated motions are driven by active forces. The physical nature of these forces and the mechanisms by which they generate collective cell migration are still not fully understood. We have developed a minimum physical model of a cell monolayer as an elastic continuum whose deformation field is coupled to two internal degrees of freedom: the concentration of a chemical signal, controlling cell Contractility, and the polarization field controlling the direction of local cell motion. By combining theory with experiments, we show that these two internal variables account for the sloshing waves and the systematic deviations of the direction of cell polarization from that of local cell velocity observed in confined cell monolayers. KJCU and MCM were supported by the Simons Foundation.

  19. Two-dimensional DNAPL migration affected by groundwater flow in unconfined aquifer.

    PubMed

    Kamon, Masashi; Endo, Kazuto; Kawabata, Junichi; Inui, Toru; Katsumi, Takeshi

    2004-07-01

    The dense non-aqueous phase liquid (DNAPL) migration process was experimentally investigated in a laboratory-scale tank (150 cm width, 82.5 cm height, and 15 cm depth) to assess a site characterization on DNAPL contamination below a groundwater table. The heterogeneous ground of the tank model consisted of Toyoura sand (hydraulic conductivity, k = 1.5 x 10(-2) cm/s for void ratio, e = 0.62) and silica #7 sand (k = 2.3 x 10(-3) cm/s for e = 0.72). A series of experiments was carried out with or without lateral groundwater flow. Hydrofluoroether was used as a representative DNAPL. The main results obtained in this study are as follows: (1) the DNAPL plume does not invade into the less permeable soil layer with higher displacement pressure head; (2) the DNAPL plume migrates faster with lateral groundwater flow than without it; (3) lateral groundwater flow does not affect lateral DNAPL migration; rather, it promotes downward migration; and (4) pore DNAPL pressure without groundwater flow is higher than that with it. The above experimental results were compared with numerical analysis. The fundamental behaviors of DNAPL source migration observed experimentally are expected to be useful for assessing the characteristics of two-dimensional DNAPL migration in an aquifer.

  20. Hedgehog inhibitors selectively target cell migration and adhesion of mantle cell lymphoma in bone marrow microenvironment

    PubMed Central

    Zhang, Han; Chen, Zheng; Neelapu, Sattva S.; Romaguera, Jorge; McCarty, Nami

    2016-01-01

    The clinical benefits of a Hedgehog (Hh) inhibitor, LDE225 (NPV-LDE-225, Erismodegib), have been unclear in hematological cancers. Here, we report that LDE225 selectively inhibited migration and adhesion of mantle cell lymphoma (MCL) to bone marrows via very late antigen-4 (VLA-4) mediated inactivation of focal adhesion kinase (FAK) signaling. LDE225 treatment not only affected MCL cells, but also modulated stromal cells within the bone marrow microenvironment by decreasing their production of SDF-1, IL-6 and VCAM-1, the ligand for VLA-4. Surprisingly, LDE225 treatment alone did not suppress cell proliferation due to increased CXCR4 expression mediated by reactive oxygen species (ROS). The increased ROS/CXCR4 further stimulated autophagy formation. The combination of LDE225 with the autophagy inhibitors further enhanced MCL cell death. Our data, for the first time, revealed LDE225 selectively targets MCL cells migration and adhesion to bone marrows. The ineffectiveness of LDE225 in MCL is due to autophagy formation, which in turn increases cell viability. Inhibiting autophagy will be an effective adjuvant therapy for LDE225 in MCL, especially for advanced MCL patients with bone marrow involvement. PMID:26885608

  1. Hedgehog inhibitors selectively target cell migration and adhesion of mantle cell lymphoma in bone marrow microenvironment.

    PubMed

    Zhang, Han; Chen, Zheng; Neelapu, Sattva S; Romaguera, Jorge; McCarty, Nami

    2016-03-22

    The clinical benefits of a Hedgehog (Hh) inhibitor, LDE225 (NPV-LDE-225, Erismodegib), have been unclear in hematological cancers. Here, we report that LDE225 selectively inhibited migration and adhesion of mantle cell lymphoma (MCL) to bone marrows via very late antigen-4 (VLA-4) mediated inactivation of focal adhesion kinase (FAK) signaling. LDE225 treatment not only affected MCL cells, but also modulated stromal cells within the bone marrow microenvironment by decreasing their production of SDF-1, IL-6 and VCAM-1, the ligand for VLA-4. Surprisingly, LDE225 treatment alone did not suppress cell proliferation due to increased CXCR4 expression mediated by reactive oxygen species (ROS). The increased ROS/CXCR4 further stimulated autophagy formation. The combination of LDE225 with the autophagy inhibitors further enhanced MCL cell death. Our data, for the first time, revealed LDE225 selectively targets MCL cells migration and adhesion to bone marrows. The ineffectiveness of LDE225 in MCL is due to autophagy formation, which in turn increases cell viability. Inhibiting autophagy will be an effective adjuvant therapy for LDE225 in MCL, especially for advanced MCL patients with bone marrow involvement. PMID:26885608

  2. Controlled architectural and chemotactic studies of 3D cell migration

    PubMed Central

    Tayalia, Prakriti; Mazur, Eric; Mooney, David

    2010-01-01

    Chemotaxis plays a critical role in tissue development and wound repair, and is widely studied using ex vivo model systems in applications such as immunotherapy. However, typical chemotactic models employ 2D systems that are less physiologically relevant or use end-point assays, that reveal little about the stepwise dynamics of the migration process. To overcome these limitations, we developed a new model system using microfabrication techniques, sustained drug delivery approaches, and theoretical modeling of chemotactic agent diffusion. This model system allows us to study the effects of 3D architecture and chemotactic agent gradient on immune cell migration in real time. We find that dendritic cell migration is characterized by a strong interplay between matrix architecture and chemotactic gradients, and migration is also influenced dramatically by the cell activation state. Our results indicate that Lipopolysaccharide-activated dendritic cells studied in a traditional transwell system actually exhibit anomalous migration behavior. Such a 3D ex vivo system lends itself for analyzing cell migratory behavior in response to single or multiple competitive cues and could prove useful in vaccine development. PMID:21237507

  3. Live cell imaging analysis of the epigenetic regulation of the human endothelial cell migration at single-cell resolution.

    PubMed

    Zheng, Chunhong; Yu, Zhilong; Zhou, Ying; Tao, Louis; Pang, Yuhong; Chen, Tao; Zhang, Xiannian; Qiu, Haiwei; Zhou, Hongwei; Chen, Zitian; Huang, Yanyi

    2012-09-01

    Epigenetic regulation plays an important role in cell migration. Although many methods have been developed to measure the motility of mammalian cells, accurate quantitative assessments of the migration speed of individual cells remain a major challenge. It is difficult for conventional scratch assays to differentiate proliferation from migration during the so-called wound-healing processes because of the long experimental time required. In addition, it is also challenging to create identical conditions for evaluating cell migration by conventional methods. We developed a microfluidic device with precisely created blanks allowing for robust and reproducible cell migration inside accurately-controlled microenvironments to study the regulatory effect of the epigenetic regulator histone deacetylase 7 (HDAC7) on cell migration. Through analyzing time-lapse imaging of the cells migrating into individual blank regions, we can measure the migration speed parameter for human primary cells within a few hours, eliminating the confounding effect of cell proliferation. We also developed an automatic image analysis and a numeric model-based data fitting to set up an integrated cell migration analysis system at single-cell resolution. Using this system, we measured the motility of primary human umbilical vein endothelial cells (HUVECs) and the migration speed reduction due to the silencing of HDAC7 and various other genes. We showed that the migration behaviour of these human primary cells are clearly regulated by epigenetic mechanisms, demonstrating the great potential of this accurate and robust assay in the fields of quantitatively migration studies and high-throughput screening.

  4. Analyzing In Vivo Cell Migration using Cell Transplantations and Time-lapse Imaging in Zebrafish Embryos.

    PubMed

    Giger, Florence A; Dumortier, Julien G; David, Nicolas B

    2016-04-29

    Cell migration is key to many physiological and pathological conditions, including cancer metastasis. The cellular and molecular bases of cell migration have been thoroughly analyzed in vitro. However, in vivo cell migration somehow differs from in vitro migration, and has proven more difficult to analyze, being less accessible to direct observation and manipulation. This protocol uses the migration of the prospective prechordal plate in the early zebrafish embryo as a model system to study the function of candidate genes in cell migration. Prechordal plate progenitors form a group of cells which, during gastrulation, undergoes a directed migration from the embryonic organizer to the animal pole of the embryo. The proposed protocol uses cell transplantation to create mosaic embryos. This offers the combined advantages of labeling isolated cells, which is key to good imaging, and of limiting gain/loss of function effects to the observed cells, hence ensuring cell-autonomous effects. We describe here how we assessed the function of the TORC2 component Sin1 in cell migration, but the protocol can be used to analyze the function of any candidate gene in controlling cell migration in vivo.

  5. Flow and Diffusion in Channel-Guided Cell Migration

    PubMed Central

    Marel, Anna-Kristina; Zorn, Matthias; Klingner, Christoph; Wedlich-Söldner, Roland; Frey, Erwin; Rädler, Joachim O.

    2014-01-01

    Collective migration of mechanically coupled cell layers is a notable feature of wound healing, embryonic development, and cancer progression. In confluent epithelial sheets, the dynamics have been found to be highly heterogeneous, exhibiting spontaneous formation of swirls, long-range correlations, and glass-like dynamic arrest as a function of cell density. In contrast, the flow-like properties of one-sided cell-sheet expansion in confining geometries are not well understood. Here, we studied the short- and long-term flow of Madin-Darby canine kidney (MDCK) cells as they moved through microchannels. Using single-cell tracking and particle image velocimetry (PIV), we found that a defined averaged stationary cell current emerged that exhibited a velocity gradient in the direction of migration and a plug-flow-like profile across the advancing sheet. The observed flow velocity can be decomposed into a constant term of directed cell migration and a diffusion-like contribution that increases with density gradient. The diffusive component is consistent with the cell-density profile and front propagation speed predicted by the Fisher-Kolmogorov equation. To connect diffusion-mediated transport to underlying cellular motility, we studied single-cell trajectories and occurrence of vorticity. We discovered that the directed large-scale cell flow altered fluctuations in cellular motion at short length scales: vorticity maps showed a reduced frequency of swirl formation in channel flow compared with resting sheets of equal cell density. Furthermore, under flow, single-cell trajectories showed persistent long-range, random-walk behavior superimposed on drift, whereas cells in resting tissue did not show significant displacements with respect to neighboring cells. Our work thus suggests that active cell migration manifests itself in an underlying, spatially uniform drift as well as in randomized bursts of short-range correlated motion that lead to a diffusion-mediated transport

  6. Tousled-like kinase regulates cytokine-mediated communication between cooperating cell types during collective border cell migration

    PubMed Central

    Xiang, Wenjuan; Zhang, Dabing; Montell, Denise J.

    2016-01-01

    Collective cell migration is emerging as a major contributor to normal development and disease. Collective movement of border cells in the Drosophila ovary requires cooperation between two distinct cell types: four to six migratory cells surrounding two immotile cells called polar cells. Polar cells secrete a cytokine, Unpaired (Upd), which activates JAK/STAT signaling in neighboring cells, stimulating their motility. Without Upd, migration fails, causing sterility. Ectopic Upd expression is sufficient to stimulate motility in otherwise immobile cells. Thus regulation of Upd is key. Here we report a limited RNAi screen for nuclear proteins required for border cell migration, which revealed that the gene encoding Tousled-like kinase (Tlk) is required in polar cells for Upd expression without affecting polar cell fate. In the absence of Tlk, fewer border cells are recruited and motility is impaired, similar to inhibition of JAK/STAT signaling. We further show that Tlk in polar cells is required for JAK/STAT activation in border cells. Genetic interactions further confirmed Tlk as a new regulator of Upd/JAK/STAT signaling. These findings shed light on the molecular mechanisms regulating the cooperation of motile and nonmotile cells during collective invasion, a phenomenon that may also drive metastatic cancer. PMID:26510500

  7. Leukotrienes induce the migration of Th17 cells.

    PubMed

    Lee, Wonyong; Su Kim, Hyeong; Lee, Gap Ryol

    2015-01-01

    Th17 cell trafficking in response to leukotriene signaling is poorly understood. Here we showed that Th17 cells express high levels of leukotriene B4 receptor 1 (LTB4R1) and cysteinyl leukotriene receptor 1 (CysLTR1). Th17 cells migrated under the guidance of leukotriene B4 and D4. The migration of Th17 cells was more efficient than that of Th1 and Th2 cells, and it was blocked by specific inhibitors of LTB4R1 or CysLTR1. Studies in an animal model of experimental autoimmune encephalomyelitis revealed that treatment with montelukast alleviated disease symptoms and inhibited the recruitment of Th17 cells to the central nervous system. Thus, leukotrienes may act as chemoattractants for Th17 cells. PMID:25512344

  8. Multidisciplinary approaches to understanding collective cell migration in developmental biology

    PubMed Central

    Schumacher, Linus J.; Kulesa, Paul M.; McLennan, Rebecca; Baker, Ruth E.; Maini, Philip K.

    2016-01-01

    Mathematical models are becoming increasingly integrated with experimental efforts in the study of biological systems. Collective cell migration in developmental biology is a particularly fruitful application area for the development of theoretical models to predict the behaviour of complex multicellular systems with many interacting parts. In this context, mathematical models provide a tool to assess the consistency of experimental observations with testable mechanistic hypotheses. In this review, we showcase examples from recent years of multidisciplinary investigations of neural crest cell migration. The neural crest model system has been used to study how collective migration of cell populations is shaped by cell–cell interactions, cell–environmental interactions and heterogeneity between cells. The wide range of emergent behaviours exhibited by neural crest cells in different embryonal locations and in different organisms helps us chart out the spectrum of collective cell migration. At the same time, this diversity in migratory characteristics highlights the need to reconcile or unify the array of currently hypothesized mechanisms through the next generation of experimental data and generalized theoretical descriptions. PMID:27278647

  9. High Glucose-Mediated Oxidative Stress Impairs Cell Migration

    PubMed Central

    Lamers, Marcelo L.; Almeida, Maíra E. S.; Vicente-Manzanares, Miguel; Horwitz, Alan F.; Santos, Marinilce F.

    2011-01-01

    Deficient wound healing in diabetic patients is very frequent, but the cellular and molecular causes are poorly defined. In this study, we evaluate the hypothesis that high glucose concentrations inhibit cell migration. Using CHO.K1 cells, NIH-3T3 fibroblasts, mouse embryonic fibroblasts and primary skin fibroblasts from control and diabetic rats cultured in 5 mM D-glucose (low glucose, LG), 25 mM D-glucose (high glucose, HG) or 25 mM L-glucose medium (osmotic control - OC), we analyzed the migration speed, protrusion stability, cell polarity, adhesion maturation and the activity of the small Rho GTPase Rac1. We also analyzed the effects of reactive oxygen species by incubating cells with the antioxidant N-Acetyl-Cysteine (NAC). We observed that HG conditions inhibited cell migration when compared to LG or OC. This inhibition resulted from impaired cell polarity, protrusion destabilization and inhibition of adhesion maturation. Conversely, Rac1 activity, which promotes protrusion and blocks adhesion maturation, was increased in HG conditions, thus providing a mechanistic basis for the HG phenotype. Most of the HG effects were partially or completely rescued by treatment with NAC. These findings demonstrate that HG impairs cell migration due to an increase in oxidative stress that causes polarity loss, deficient adhesion and protrusion. These alterations arise, in large part, from increased Rac1 activity and may contribute to the poor wound healing observed in diabetic patients. PMID:21826213

  10. Cell migration in paediatric glioma; characterisation and potential therapeutic targeting

    PubMed Central

    Cockle, J V; Picton, S; Levesley, J; Ilett, E; Carcaboso, A M; Short, S; Steel, L P; Melcher, A; Lawler, S E; Brüning-Richardson, A

    2015-01-01

    Background: Paediatric high grade glioma (pHGG) and diffuse intrinsic pontine glioma (DIPG) are highly aggressive brain tumours. Their invasive phenotype contributes to their limited therapeutic response, and novel treatments that block brain tumour invasion are needed. Methods: Here, we examine the migratory characteristics and treatment effect of small molecule glycogen synthase kinase-3 inhibitors, lithium chloride (LiCl) and the indirubin derivative 6-bromoindirubin-oxime (BIO), previously shown to inhibit the migration of adult glioma cells, on two pHGG cell lines (SF188 and KNS42) and one patient-derived DIPG line (HSJD-DIPG-007) using 2D (transwell membrane, immunofluorescence, live cell imaging) and 3D (migration on nanofibre plates and spheroid invasion in collagen) assays. Results: All lines were migratory, but there were differences in morphology and migration rates. Both LiCl and BIO reduced migration and instigated cytoskeletal rearrangement of stress fibres and focal adhesions when viewed by immunofluorescence. In the presence of drugs, loss of polarity and differences in cellular movement were observed by live cell imaging. Conclusions: Ours is the first study to demonstrate that it is possible to pharmacologically target migration of paediatric glioma in vitro using LiCl and BIO, and we conclude that these agents and their derivatives warrant further preclinical investigation as potential anti-migratory therapeutics for these devastating tumours. PMID:25628092

  11. Epac Activation Regulates Human Mesenchymal Stem Cells Migration and Adhesion.

    PubMed

    Yu, Jiao-Le; Deng, Ruixia; Chung, Sookja K; Chan, Godfrey Chi-Fung

    2016-04-01

    How to enhance the homing of human mesenchymal stem cells (hMSCs) to the target tissues remains a clinical challenge nowadays. To overcome this barrier, the mechanism responsible for the hMSCs migration and engraftment has to be defined. Currently, the exact mechanism involved in migration and adhesion of hMSCs remains unknown. Exchange protein directly activated by cAMP (Epac), a novel protein discovered in cAMP signaling pathway, may have a potential role in regulating cells adhesion and migration by triggering the downstream Rap family signaling cascades. However, the exact role of Epac in cells homing is elusive. Our study evaluated the role of Epac in the homing of hMSCs. We confirmed that hMSCs expressed functional Epac and its activation enhanced the migration and adhesion of hMSCs significantly. The Epac activation was further found to be contributed directly to the chemotactic responses induced by stromal cell derived factor-1 (SDF-1) which is a known chemokine in regulating hMSCs homing. These findings suggested Epac is connected to the SDF-1 signaling cascades. In conclusion, our study revealed that Epac plays a role in hMSCs homing by promoting adhesion and migration. Appropriate manipulation of Epac may enhance the homing of hMSCs and facilitate their future clinical applications. PMID:26727165

  12. Eribulin targets a ch-TOG-dependent directed migration of cancer cells.

    PubMed

    Chanez, Brice; Gonçalves, Anthony; Badache, Ali; Verdier-Pinard, Pascal

    2015-12-01

    Non-cytotoxic concentrations of microtubule targeting agents (MTAs) interfere with the dynamics of interphase microtubules and affect cell migration, which could impair tumor angiogenesis and metastasis. The underlying mechanisms however are still ill-defined. We previously established that directed cell migration is dependent on stabilization of microtubules at the cell leading edge, which is controlled by microtubule +end interacting proteins (+TIPs). In the present study, we found that eribulin, a recently approved MTA interacting with a new class of binding site on β-tubulin, decreased microtubule growth speed, impaired their cortical stabilization and prevented directed migration of cancer cells. These effects were reminiscent of those observed when +TIP expression or cortical localization was altered. Actually, eribulin induced a dose-dependent depletion of EB1, CLIP-170 and the tubulin polymerase ch-TOG from microtubule +ends. Interestingly, eribulin doses that disturbed ch-TOG localization without significant effect on EB1 and CLIP-170 comets, had an impact on microtubule dynamics and directed migration. Moreover, knockdown of ch-TOG led to a similar inhibition of microtubule growth speed, microtubule capture and chemotaxis. Our data suggest that eribulin binding to the tip of microtubules and subsequent loss of ch-TOG is a priming event leading to alterations in microtubule dynamics and cancer cell migration. PMID:26497677

  13. MiR-340 suppresses cell migration and invasion by targeting MYO10 in breast cancer.

    PubMed

    Chen, Cai-Ping; Sun, Zong-Lin; Lu, Xiang; Wu, Wan-Xin; Guo, Wen-Li; Lu, Jian-Ju; Han, Chao; Huang, Jian-Qi; Fang, Ying

    2016-02-01

    Breast cancer is one of the most common malignant tumors among females, and can seriously affect the physical and mental health and even threaten the lives of women. Recently, research has demonstrated that microRNAs (miRNAs), as a new method of regulation, have been shown to have oncogenic and tumor‑suppressive functions in human breast cancer. Detection of their expression may lead to the identification of novel markers for breast cancer. In the present study, we firstly detected miR‑340 expression and found lower expression of miR‑340 in 6 human breast cancer cell lines by using RT‑qPCR. Then by using wound healing assay and Transwell migration and invasion experiments, we focused on the role of miR-340 in the regulation of tumor cell migration and invasion, exploring the relationship between them. The results revealed that induction of miR‑340 expression was able to suppress tumor cell migration and invasion, whereas knockdown of miR‑340 expression promoted breast cancer cell migration and invasion. At the gene level, MYO10 (myosin X), as a direct miR‑340 target gene, mediated the cell migration and invasion. Finally, we verified our research further at the tissue specimen level and in animal experiments. In brief, miR‑340 plays an important role in breast cancer progression. Thus, miR‑340 may be further explored as a novel biomarker for breast cancer metastasis and prognosis, and potentially a therapeutic target.

  14. Intermediate filaments in cell migration and invasion: the unusual suspects.

    PubMed

    Leduc, Cécile; Etienne-Manneville, Sandrine

    2015-02-01

    Cell migration is a multistep process which relies on the coordination of cytoskeletal structures in space and time. While the roles of actin and microtubules have been investigated in great details, the lack of inhibitors and visualizing tools and the large number of proteins forming intermediate filaments (IFs) have delayed the characterization of IF functions during migration. However, a large body of evidence has progressively pointed to changes in IF composition as an important parameter in the regulation of cell migratory properties both during development and tumor invasion. More recent in-depth analyses show that IFs are dynamically reorganized to participate, together with microfilaments and microtubules, to the key steps leading to cell migration.

  15. Modeling keratinocyte wound healing dynamics: Cell-cell adhesion promotes sustained collective migration.

    PubMed

    Nardini, John T; Chapnick, Douglas A; Liu, Xuedong; Bortz, David M

    2016-07-01

    The in vitro migration of keratinocyte cell sheets displays behavioral and biochemical similarities to the in vivo wound healing response of keratinocytes in animal model systems. In both cases, ligand-dependent Epidermal Growth Factor Receptor (EGFR) activation is sufficient to elicit collective cell migration into the wound. Previous mathematical modeling studies of in vitro wound healing assays assume that physical connections between cells have a hindering effect on cell migration, but biological literature suggests a more complicated story. By combining mathematical modeling and experimental observations of collectively migrating sheets of keratinocytes, we investigate the role of cell-cell adhesion during in vitro keratinocyte wound healing assays. We develop and compare two nonlinear diffusion models of the wound healing process in which cell-cell adhesion either hinders or promotes migration. Both models can accurately fit the leading edge propagation of cell sheets during wound healing when using a time-dependent rate of cell-cell adhesion strength. The model that assumes a positive role of cell-cell adhesion on migration, however, is robust to changes in the leading edge definition and yields a qualitatively accurate density profile. Using RNAi for the critical adherens junction protein, α-catenin, we demonstrate that cell sheets with wild type cell-cell adhesion expression maintain migration into the wound longer than cell sheets with decreased cell-cell adhesion expression, which fails to exhibit collective migration. Our modeling and experimental data thus suggest that cell-cell adhesion promotes sustained migration as cells pull neighboring cells into the wound during wound healing.

  16. Modeling keratinocyte wound healing dynamics: Cell-cell adhesion promotes sustained collective migration.

    PubMed

    Nardini, John T; Chapnick, Douglas A; Liu, Xuedong; Bortz, David M

    2016-07-01

    The in vitro migration of keratinocyte cell sheets displays behavioral and biochemical similarities to the in vivo wound healing response of keratinocytes in animal model systems. In both cases, ligand-dependent Epidermal Growth Factor Receptor (EGFR) activation is sufficient to elicit collective cell migration into the wound. Previous mathematical modeling studies of in vitro wound healing assays assume that physical connections between cells have a hindering effect on cell migration, but biological literature suggests a more complicated story. By combining mathematical modeling and experimental observations of collectively migrating sheets of keratinocytes, we investigate the role of cell-cell adhesion during in vitro keratinocyte wound healing assays. We develop and compare two nonlinear diffusion models of the wound healing process in which cell-cell adhesion either hinders or promotes migration. Both models can accurately fit the leading edge propagation of cell sheets during wound healing when using a time-dependent rate of cell-cell adhesion strength. The model that assumes a positive role of cell-cell adhesion on migration, however, is robust to changes in the leading edge definition and yields a qualitatively accurate density profile. Using RNAi for the critical adherens junction protein, α-catenin, we demonstrate that cell sheets with wild type cell-cell adhesion expression maintain migration into the wound longer than cell sheets with decreased cell-cell adhesion expression, which fails to exhibit collective migration. Our modeling and experimental data thus suggest that cell-cell adhesion promotes sustained migration as cells pull neighboring cells into the wound during wound healing. PMID:27105673

  17. Collisions of deformable cells lead to collective migration

    SciTech Connect

    Löber, Jakob; Ziebert, Falko; Aranson, Igor S.

    2015-03-17

    Collective migration of eukaryotic cells plays a fundamental role in tissue growth, wound healing and immune response. The motion, arising spontaneously or in response to chemical and mechanical stimuli, is also important for understanding life-threatening pathologies, such as cancer and metastasis formation. We present a phase-field model to describe the movement of many self-organized, interacting cells. The model takes into account the main mechanisms of cell motility – acto-myosin dynamics, as well as substrate-mediated and cell-cell adhesion. It predicts that collective cell migration emerges spontaneously as a result of inelastic collisions between neighboring cells: collisions lead to a mutual alignment of the cell velocities and to the formation of coherently-moving multi-cellular clusters. Small cell-to-cell adhesion, in turn, reduces the propensity for large-scale collective migration, while higher adhesion leads to the formation of moving bands. Our study provides valuable insight into biological processes associated with collective cell motility.

  18. Collisions of deformable cells lead to collective migration

    DOE PAGES

    Löber, Jakob; Ziebert, Falko; Aranson, Igor S.

    2015-03-17

    Collective migration of eukaryotic cells plays a fundamental role in tissue growth, wound healing and immune response. The motion, arising spontaneously or in response to chemical and mechanical stimuli, is also important for understanding life-threatening pathologies, such as cancer and metastasis formation. We present a phase-field model to describe the movement of many self-organized, interacting cells. The model takes into account the main mechanisms of cell motility – acto-myosin dynamics, as well as substrate-mediated and cell-cell adhesion. It predicts that collective cell migration emerges spontaneously as a result of inelastic collisions between neighboring cells: collisions lead to a mutual alignmentmore » of the cell velocities and to the formation of coherently-moving multi-cellular clusters. Small cell-to-cell adhesion, in turn, reduces the propensity for large-scale collective migration, while higher adhesion leads to the formation of moving bands. Our study provides valuable insight into biological processes associated with collective cell motility.« less

  19. Cell-permeable p38 MAP kinase promotes migration of adult neural stem/progenitor cells

    PubMed Central

    Hamanoue, Makoto; Morioka, Kazuhito; Ohsawa, Ikuroh; Ohsawa, Keiko; Kobayashi, Masaaki; Tsuburaya, Kayo; Akasaka, Yoshikiyo; Mikami, Tetsuo; Ogata, Toru; Takamatsu, Ken

    2016-01-01

    Endogenous neural stem/progenitor cells (NPCs) can migrate toward sites of injury, but the migration activity of NPCs is insufficient to regenerate damaged brain tissue. In this study, we showed that p38 MAP kinase (p38) is expressed in doublecortin-positive adult NPCs. Experiments using the p38 inhibitor SB203580 revealed that endogenous p38 participates in NPC migration. To enhance NPC migration, we generated a cell-permeable wild-type p38 protein (PTD-p38WT) in which the HIV protein transduction domain (PTD) was fused to the N-terminus of p38. Treatment with PTD-p38WT significantly promoted the random migration of adult NPCs without affecting cell survival or differentiation; this effect depended on the cell permeability and kinase activity of the fusion protein. These findings indicate that PTD-p38WT is a novel and useful tool for unraveling the roles of p38, and that this protein provides a reasonable approach for regenerating the injured brain by enhancing NPC migration. PMID:27067799

  20. Single-cell Migration Chip for Chemotaxis-based Microfluidic Selection of Heterogeneous Cell Populations

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Chih; Allen, Steven G.; Ingram, Patrick N.; Buckanovich, Ronald; Merajver, Sofia D.; Yoon, Euisik

    2015-05-01

    Tumor cell migration toward and intravasation into capillaries is an early and key event in cancer metastasis, yet not all cancer cells are imbued with the same capability to do so. This heterogeneity within a tumor is a fundamental property of cancer. Tools to help us understand what molecular characteristics allow a certain subpopulation of cells to spread from the primary tumor are thus critical for overcoming metastasis. Conventional in vitro migration platforms treat populations in aggregate, which leads to a masking of intrinsic differences among cells. Some migration assays reported recently have single-cell resolution, but these platforms do not provide for selective retrieval of the distinct migrating and non-migrating cell populations for further analysis. Thus, to study the intrinsic differences in cells responsible for chemotactic heterogeneity, we developed a single-cell migration platform so that individual cells’ migration behavior can be studied and the heterogeneous population sorted based upon chemotactic phenotype. Furthermore, after migration, the highly chemotactic and non-chemotactic cells were retrieved and proved viable for later molecular analysis of their differences. Moreover, we modified the migration channel to resemble lymphatic capillaries to better understand how certain cancer cells are able to move through geometrically confining spaces.

  1. Substrate properties affect collective cell motion

    NASA Astrophysics Data System (ADS)

    Pegoraro, Adrian; Guo, Ming; Ehrlicher, Allen; Weitz, David

    2013-03-01

    When cells move collectively, cooperative motion, which is characterized by long range correlations in cell movement, is necessary for migration. This collective cell motion is influenced by cell-cell interactions as well as by cell-substrate coupling. Furthermore, on soft substrates it is possible for cells to mechanically couple over long distances through the substrate itself. By changing the properties of the substrate, it is possible to decouple some of these contributions and better understand the role they play in collective cell motion. We vary both the substrate stiffness and adhesion protein concentration and find changes in the collective cell motion of the cells despite only small differences in total cell density and average cell size in the confluent layers. We test these changes on polyacrylamide and PDMS substrates as well as on structured substrates made of PDMS posts that prevent mechanical coupling through the substrate while still allowing stiffness to be varied.

  2. Electrolytic cell stack with molten electrolyte migration control

    DOEpatents

    Kunz, H.R.; Guthrie, R.J.; Katz, M.

    1987-03-17

    An electrolytic cell stack includes inactive electrolyte reservoirs at the upper and lower end portions thereof. The reservoirs are separated from the stack of the complete cells by impermeable, electrically conductive separators. Reservoirs at the negative end are initially low in electrolyte and the reservoirs at the positive end are high in electrolyte fill. During stack operation electrolyte migration from the positive to the negative end will be offset by the inactive reservoir capacity. In combination with the inactive reservoirs, a sealing member of high porosity and low electrolyte retention is employed to limit the electrolyte migration rate. 5 figs.

  3. Electrolytic cell stack with molten electrolyte migration control

    DOEpatents

    Kunz, H. Russell; Guthrie, Robin J.; Katz, Murray

    1988-08-02

    An electrolytic cell stack includes inactive electrolyte reservoirs at the upper and lower end portions thereof. The reservoirs are separated from the stack of the complete cells by impermeable, electrically conductive separators. Reservoirs at the negative end are initially low in electrolyte and the reservoirs at the positive end are high in electrolyte fill. During stack operation electrolyte migration from the positive to the negative end will be offset by the inactive reservoir capacity. In combination with the inactive reservoirs, a sealing member of high porosity and low electrolyte retention is employed to limit the electrolyte migration rate.

  4. SIRT1 regulates lamellipodium extension and migration of melanoma cells.

    PubMed

    Kunimoto, Risa; Jimbow, Kowichi; Tanimura, Akihiko; Sato, Masahiro; Horimoto, Kouhei; Hayashi, Takashi; Hisahara, Shin; Sugino, Toshiya; Hirobe, Tomohisa; Yamashita, Toshiharu; Horio, Yoshiyuki

    2014-06-01

    Melanoma is highly metastatic, but the mechanism of melanoma cell migration is still unclear. We found that melanoma cells expressed the nicotinamide adenine dinucleotide-dependent protein deacetylase SIRT1 in the cytoplasm. Cell membrane extension and migration of melanoma cells were inhibited by SIRT1 inhibitors or SIRT1 knockdown, whereas SIRT1 activators enhanced elongation of protrusion and cellular motility. In B16F1 cells, growth factor stimulation induced lamellipodium extension, a characteristic feature at the leading edge of migrating cells, and SIRT1 was found in the lamellipodium. SIRT1 inhibitor nicotinamide (NAM) or SIRT1 small interfering RNAs suppressed the lamellipodium extension by serum or platelet-derived growth factor (PDGF). The lamellipodium formation by dominant-active Rac1 was also inhibited by NAM, a SIRT1 inhibitor. NAM inhibited the accumulation of phosphorylated Akt at the submembrane by serum or PDGF. Using fluorescence resonance energy transfer, we found that NAM impaired PDGF-dependent increase in the phosphatidylinositol-3,4,5-trisphosphate level at the leading edge. NAM inhibited the abdominal metastasis of transplanted B16F1 melanoma cells in C57BL6/J mice and improved survival. Finally, SIRT1-knockdown B16F1 cells showed significantly reduced metastasis in transplanted mice compared with that in control B16F1 cells. These results indicate that SIRT1 inhibition is a strategy to suppress metastasis of melanoma cells. PMID:24480879

  5. Nuclear envelope rupture and repair during cancer cell migration

    PubMed Central

    Denais, Celine M.; Gilbert, Rachel M.; Isermann, Philipp; McGregor, Alexandra L.; te Lindert, Mariska; Weigelin, Bettina; Davidson, Patricia M.; Friedl, Peter; Wolf, Katarina; Lammerding, Jan

    2016-01-01

    During cancer metastasis, tumor cells penetrate tissues through tight interstitial spaces, requiring extensive deformation of the cell and its nucleus. Here, we investigated tumor cell migration in confining microenvironments in vitro and in vivo. Nuclear deformation caused localized loss of nuclear envelope (NE) integrity, which led to the uncontrolled exchange of nucleo-cytoplasmic content, herniation of chromatin across the NE, and DNA damage. The incidence of NE rupture increased with cell confinement and with depletion of nuclear lamins, NE proteins that structurally support the nucleus. Cells restored NE integrity using components of the endosomal sorting complexes required for transport-III (ESCRT-III) machinery. Our findings indicate that cell migration incurs substantial physical stress on the NE and its content, requiring efficient NE and DNA damage repair for survival. PMID:27013428

  6. Molecular analysis of cell surface beta-1,4-galactosyltransferase function during cell migration.

    PubMed Central

    Appeddu, P A; Shur, B D

    1994-01-01

    Despite the identification and characterization of cell surface receptors for the extracellular matrix, it is unknown how their relative expression and cytoskeletal association regulate cell migration. Previous studies have identified beta-1,4-galactosyltransferase (GalTase; EC 2.4.1.38) on the surface of migrating cells, where it mediates cell migration on basal lamina matrices by associating with the cytoskeleton and binding to N-linked oligosaccharides in the E8 domain of laminin. In this study, the function of GalTase during cell migration was examined directly by analyzing the migration rate of stably transfected cell lines in which the relative level of surface GalTase and its ability to associate with the cytoskeleton were altered. We show here that the cytoskeleton contains a limiting, saturable, number of binding sites for surface GalTase. Furthermore, the rate of cell migration was inversely related to the ability of surface GalTase to associate with the cytoskeleton. Elevating surface GalTase in excess of the number of cytoskeleton-binding sites reduced the rate of cell migration, whereas decreasing the amount of surface GalTase available to bind the cytoskeleton increased migration rates. These results show that the rate of cell migration on basal lamina is directly dependent upon the expression of surface GalTase and the ability of this protein to associate with a limiting number of cytoskeleton-binding sites. Images PMID:8134355

  7. Study of dendritic cell migration using micro-fabrication.

    PubMed

    Vargas, Pablo; Chabaud, Mélanie; Thiam, Hawa-Racine; Lankar, Danielle; Piel, Matthieu; Lennon-Dumenil, Ana-Maria

    2016-05-01

    Cell migration is a hallmark of dendritic cells (DCs) function. It is needed for DCs to scan their environment in search for antigens as well as to reach lymphatic organs in order to trigger T lymphocyte's activation. Such interaction leads to tolerance in the case of DCs migrating under homeostatic conditions or to immunity in the case of DCs migrating upon encounter with pathogen-associated molecular patterns. Cell migration is therefore essential for DCs to transfer information from peripheral tissues to lymphoid organs, thereby linking innate to adaptive immunity. This stresses the need to unravel the molecular mechanisms involved. However, the tremendous complexity of the tissue microenvironment as well as the limited spatio-temporal resolution of in vivo imaging techniques has made this task difficult. To bypass this problem, we have developed microfabrication-based experimental tools that are compatible with high-resolution imaging. Here, we will discuss how such devices can be used to study DC migration under controlled conditions that mimic their physiological environment in a robust quantitative manner.

  8. Regulation of human natural killer cell migration and proliferation by the exodus subfamily of CC chemokines.

    PubMed

    Robertson, M J; Williams, B T; Christopherson, K; Brahmi, Z; Hromas, R

    2000-01-10

    Natural killer (NK) cells play an important role in innate and adaptive immune responses to obligate intracellular pathogens. Nevertheless, the regulation of NK cell trafficking and migration to inflammatory sites is poorly understood. Exodus-1/MIP-3alpha/LARC, Exodus-2/6Ckine/SLC, and Exodus-3/MIP-3beta/ELC/CKbeta-11 are CC chemokines that share a unique aspartate-cysteine-cysteine-leucine motif near their amino terminus and preferentially stimulate the migration of T lymphocytes. The effects of Exodus chemokines on human NK cells were examined. Exodus-1, -2, and -3 did not induce detectable chemotaxis of resting peripheral blood NK cells. In contrast, Exodus-2 and -3 stimulated migration of polyclonal activated peripheral blood NK cells in a dose-dependent fashion. Exodus-2 and -3 also induced dose-dependent chemotaxis of NKL, an IL-2-dependent human NK cell line. Results of modified checkerboard assays indicate that migration of NKL cells in response to Exodus-2 and -3 represents true chemotaxis and not simply chemokinesis. Exodus-1, -2, and -3 did not induce NK cell proliferation in the absence of other stimuli. Nevertheless, Exodus-2 and -3 significantly augmented IL-2-induced proliferation of normal human CD56(dim) NK cells. In contrast, Exodus-1, -2, and -3 did not affect the cytolytic activity of resting or activated peripheral blood NK cells. Expression of message for CCR7, a shared receptor for Exodus-2 and -3, was detected in activated polyclonal NK cells and NKL cells but not resting NK cells. Taken together, these results indicate that Exodus-2 and -3 can participate in the recruitment and proliferation of activated NK cells. Exodus-2 and -3 may regulate interactions between T cells and NK cells that are crucial for the generation of optimal immune responses.

  9. Cell surface syndecan-1 contributes to binding and function of macrophage migration inhibitory factor (MIF) on epithelial tumor cells.

    PubMed

    Pasqualon, Tobias; Lue, Hongqi; Groening, Sabine; Pruessmeyer, Jessica; Jahr, Holger; Denecke, Bernd; Bernhagen, Jürgen; Ludwig, Andreas

    2016-04-01

    Surface expressed proteoglycans mediate the binding of cytokines and chemokines to the cell surface and promote migration of various tumor cell types including epithelial tumor cells. We here demonstrate that binding of the chemokine-like inflammatory cytokine macrophage migration inhibitory factor (MIF) to epithelial lung and breast tumor cell lines A549 and MDA-MB231 is sensitive to enzymatic digestion of heparan sulphate chains and competitive inhibition with heparin. Moreover, MIF interaction with heparin was confirmed by chromatography and a structural comparison indicated a possible heparin binding site. These results suggested that proteoglycans carrying heparan sulphate chains are involved in MIF binding. Using shRNA-mediated gene silencing, we identified syndecan-1 as the predominant proteoglycan required for the interaction with MIF. MIF binding was decreased by induction of proteolytic shedding of syndecan-1, which could be prevented by inhibition of the metalloproteinases involved in this process. Finally, MIF induced the chemotactic migration of A549 cells, wound closure and invasion into matrigel without affecting cell proliferation. These MIF-induced responses were abrogated by heparin or by silencing of syndecan-1. Thus, our study indicates that syndecan-1 on epithelial tumor cells promotes MIF binding and MIF-mediated cell migration. This may represent a relevant mechanism through which MIF enhances tumor cell motility and metastasis.

  10. Topographic cell instructive patterns to control cell adhesion, polarization and migration

    PubMed Central

    Ventre, Maurizio; Natale, Carlo Fortunato; Rianna, Carmela; Netti, Paolo Antonio

    2014-01-01

    Topographic patterns are known to affect cellular processes such as adhesion, migration and differentiation. However, the optimal way to deliver topographic signals to provide cells with precise instructions has not been defined yet. In this work, we hypothesize that topographic patterns may be able to control the sensing and adhesion machinery of cells when their interval features are tuned on the characteristic lengths of filopodial probing and focal adhesions (FAs). Features separated by distance beyond the length of filopodia cannot be readily perceived; therefore, the formation of new adhesions is discouraged. If, however, topographic features are separated by a distance within the reach of filopodia extension, cells can establish contact between adjacent topographic islands. In the latter case, cell adhesion and polarization rely upon the growth of FAs occurring on a specific length scale that depends on the chemical properties of the surface. Topographic patterns and chemical properties may interfere with the growth of FAs, thus making adhesions unstable. To test this hypothesis, we fabricated different micropatterned surfaces displaying feature dimensions and adhesive properties able to interfere with the filopodial sensing and the adhesion maturation, selectively. Our data demonstrate that it is possible to exert a potent control on cell adhesion, elongation and migration by tuning topographic features’ dimensions and surface chemistry. PMID:25253035

  11. Glucocorticoid receptor beta increases migration of human bladder cancer cells.

    PubMed

    McBeth, Lucien; Nwaneri, Assumpta C; Grabnar, Maria; Demeter, Jonathan; Nestor-Kalinoski, Andrea; Hinds, Terry D

    2016-05-10

    Bladder cancer is observed worldwide having been associated with a host of environmental and lifestyle risk factors. Recent investigations on anti-inflammatory glucocorticoid signaling point to a pathway that may impact bladder cancer. Here we show an inverse effect on the glucocorticoid receptor (GR) isoform signaling that may lead to bladder cancer. We found similar GRα expression levels in the transitional uroepithelial cancer cell lines T24 and UMUC-3. However, the T24 cells showed a significant (p < 0.05) increased expression of GRβ compared to UMUC-3, which also correlated with higher migration rates. Knockdown of GRβ in the T24 cells resulted in a decreased migration rate. Mutational analysis of the 3' untranslated region (UTR) of human GRβ revealed that miR144 might positively regulate expression. Indeed, overexpression of miR144 increased GRβ by 3.8 fold. In addition, miR144 and GRβ were upregulated during migration. We used a peptide nucleic acid conjugated to a cell penetrating-peptide (Sweet-P) to block the binding site for miR144 in the 3'UTR of GRβ. Sweet-P effectively prevented miR144 actions and decreased GRβ expression, as well as the migration of the T24 human bladder cancer cells. Therefore, GRβ may have a significant role in bladder cancer, and possibly serve as a therapeutic target for the disease. PMID:27036026

  12. A lateral signalling pathway coordinates shape volatility during cell migration

    PubMed Central

    Zhang, Liang; Luga, Valbona; Armitage, Sarah K.; Musiol, Martin; Won, Amy; Yip, Christopher M.; Plotnikov, Sergey V.; Wrana, Jeffrey L.

    2016-01-01

    Cell migration is fundamental for both physiological and pathological processes. Migrating cells usually display high dynamics in morphology, which is orchestrated by an integrative array of signalling pathways. Here we identify a novel pathway, we term lateral signalling, comprised of the planar cell polarity (PCP) protein Pk1 and the RhoGAPs, Arhgap21/23. We show that the Pk1–Arhgap21/23 complex inhibits RhoA, is localized on the non-protrusive lateral membrane cortex and its disruption leads to the disorganization of the actomyosin network and altered focal adhesion dynamics. Pk1-mediated lateral signalling confines protrusive activity and is regulated by Smurf2, an E3 ubiquitin ligase in the PCP pathway. Furthermore, we demonstrate that dynamic interplay between lateral and protrusive signalling generates cyclical fluctuations in cell shape that we quantify here as shape volatility, which strongly correlates with migration speed. These studies uncover a previously unrecognized lateral signalling pathway that coordinates shape volatility during productive cell migration. PMID:27226243

  13. Glucocorticoid receptor beta increases migration of human bladder cancer cells

    PubMed Central

    McBeth, Lucien; Nwaneri, Assumpta C.; Grabnar, Maria; Demeter, Jonathan; Nestor-Kalinoski, Andrea; Hinds, Terry D.

    2016-01-01

    Bladder cancer is observed worldwide having been associated with a host of environmental and lifestyle risk factors. Recent investigations on anti-inflammatory glucocorticoid signaling point to a pathway that may impact bladder cancer. Here we show an inverse effect on the glucocorticoid receptor (GR) isoform signaling that may lead to bladder cancer. We found similar GRα expression levels in the transitional uroepithelial cancer cell lines T24 and UMUC-3. However, the T24 cells showed a significant (p < 0.05) increased expression of GRβ compared to UMUC-3, which also correlated with higher migration rates. Knockdown of GRβ in the T24 cells resulted in a decreased migration rate. Mutational analysis of the 3′ untranslated region (UTR) of human GRβ revealed that miR144 might positively regulate expression. Indeed, overexpression of miR144 increased GRβ by 3.8 fold. In addition, miR144 and GRβ were upregulated during migration. We used a peptide nucleic acid conjugated to a cell penetrating-peptide (Sweet-P) to block the binding site for miR144 in the 3′UTR of GRβ. Sweet-P effectively prevented miR144 actions and decreased GRβ expression, as well as the migration of the T24 human bladder cancer cells. Therefore, GRβ may have a significant role in bladder cancer, and possibly serve as a therapeutic target for the disease. PMID:27036026

  14. Optimal chemotaxis in intermittent migration of animal cells

    NASA Astrophysics Data System (ADS)

    Romanczuk, P.; Salbreux, G.

    2015-04-01

    Animal cells can sense chemical gradients without moving and are faced with the challenge of migrating towards a target despite noisy information on the target position. Here we discuss optimal search strategies for a chaser that moves by switching between two phases of motion ("run" and "tumble"), reorienting itself towards the target during tumble phases, and performing persistent migration during run phases. We show that the chaser average run time can be adjusted to minimize the target catching time or the spatial dispersion of the chasers. We obtain analytical results for the catching time and for the spatial dispersion in the limits of small and large ratios of run time to tumble time and scaling laws for the optimal run times. Our findings have implications for optimal chemotactic strategies in animal cell migration.

  15. Optimal chemotaxis in intermittent migration of animal cells.

    PubMed

    Romanczuk, P; Salbreux, G

    2015-04-01

    Animal cells can sense chemical gradients without moving and are faced with the challenge of migrating towards a target despite noisy information on the target position. Here we discuss optimal search strategies for a chaser that moves by switching between two phases of motion ("run" and "tumble"), reorienting itself towards the target during tumble phases, and performing persistent migration during run phases. We show that the chaser average run time can be adjusted to minimize the target catching time or the spatial dispersion of the chasers. We obtain analytical results for the catching time and for the spatial dispersion in the limits of small and large ratios of run time to tumble time and scaling laws for the optimal run times. Our findings have implications for optimal chemotactic strategies in animal cell migration.

  16. Short-Lived, Transitory Cell-Cell Interactions Foster Migration-Dependent Aggregation

    PubMed Central

    Pope, Melissa D.; Asthagiri, Anand R.

    2012-01-01

    During embryonic development, motile cells aggregate into cohesive groups, which give rise to tissues and organs. The role of cell migration in regulating aggregation is unclear. The current paradigm for aggregation is based on an equilibrium model of differential cell adhesivity to neighboring cells versus the underlying substratum. In many biological contexts, however, dynamics is critical. Here, we provide evidence that multicellular aggregation dynamics involves both local adhesive interactions and transport by cell migration. Using time-lapse video microscopy, we quantified the duration of cell-cell contacts among migrating cells that collided and adhered to another cell. This lifetime of cell-cell interactions exhibited a monotonic decreasing dependence on substratum adhesivity. Parallel quantitative measurements of cell migration speed revealed that across the tested range of adhesive substrata, the mean time needed for cells to migrate and encounter another cell was greater than the mean adhesion lifetime, suggesting that aggregation dynamics may depend on cell motility instead of the local differential adhesivity of cells. Consistent with this hypothesis, aggregate size exhibited a biphasic dependence on substratum adhesivity, matching the trend we observed for cell migration speed. Our findings suggest a new role for cell motility, alongside differential adhesion, in regulating developmental aggregation events and motivate new design principles for tuning aggregation dynamics in tissue engineering applications. PMID:22912835

  17. Knockdown of Legumain Suppresses Cervical Cancer Cell Migration and Invasion.

    PubMed

    Meng, Fei; Liu, Wei

    2016-01-01

    Cervical cancer is the second leading type of cancer in women living in less developed countries. The pathological and molecular mechanisms of cervical cancer are not comprehensively known. Though legumain has been found to be highly expressed in various types of solid tumors, its expression and biological function in cervical cancer remain unknown. In this study, we aimed to investigate legumain expression and functions in cervical cancer. We found that legumain was highly expressed in cervical cancer cells. When knocked down, legumain expression in HeLa and SiHa cells significantly reduced its migration and invasion abilities compared with control cells. Furthermore, legumain silencing suppressed the activation of matrix metalloproteases (MMP2 and MMP3) in cervical cancer cells. This study indicates that legumain might play an important role in cervical cancer cell migration and invasion. Legumain might be a potential therapeutic target for cervical cancer therapy.

  18. Fascin Regulates Nuclear Movement and Deformation in Migrating Cells.

    PubMed

    Jayo, Asier; Malboubi, Majid; Antoku, Susumu; Chang, Wakam; Ortiz-Zapater, Elena; Groen, Christopher; Pfisterer, Karin; Tootle, Tina; Charras, Guillaume; Gundersen, Gregg G; Parsons, Maddy

    2016-08-22

    Fascin is an F-actin-bundling protein shown to stabilize filopodia and regulate adhesion dynamics in migrating cells, and its expression is correlated with poor prognosis and increased metastatic potential in a number of cancers. Here, we identified the nuclear envelope protein nesprin-2 as a binding partner for fascin in a range of cell types in vitro and in vivo. Nesprin-2 interacts with fascin through a direct, F-actin-independent interaction, and this binding is distinct and separable from a role for fascin within filopodia at the cell periphery. Moreover, disrupting the interaction between fascin and nesprin-2 C-terminal domain leads to specific defects in F-actin coupling to the nuclear envelope, nuclear movement, and the ability of cells to deform their nucleus to invade through confined spaces. Together, our results uncover a role for fascin that operates independently of filopodia assembly to promote efficient cell migration and invasion. PMID:27554857

  19. Quantification of hydrodynamic factors influencing cell lateral migration

    NASA Astrophysics Data System (ADS)

    Nix, Stephanie; Imai, Yohsuke; Ishikawa, Takuji

    2015-11-01

    The study of the migration of blood cells perpendicular to the direction of blood flow, or lateral migration, is motivated by the differing behavior of the various types of blood cells. In vivo, red blood cells are observed to flow in the central region of the blood vessel, particularly in the microcirculation, while other types of cells in the blood, including white blood cells and platelets, are observed to flow disproportionately near the vessel wall. However, the specifics regarding the effect of hydrodynamic and biological factors are still unknown. Thus, in this study, we aim to quantify the effect of hydrodynamic factors on a cell model numerically using the boundary integral method. By using the boundary integral method, we can isolate the effect of a single hydrodynamic factor, such as a wall or given flow distribution, in an otherwise infinite flow. Then, we can use the obtained numerical results to develop a semi-analytical model describing the cell lateral migration dependent on only the flow geometry and the viscosity ratio between the cell and external fluid.

  20. Syndecan-1 Regulates Cell Migration and Fibronectin Fibril Assembly

    PubMed Central

    Stepp, Mary Ann; Daley, William P.; Bernstein, Audrey M.; Pal-Ghosh, Sonali; Tadvalkar, Gauri; Shashurin, Alexey; Palsen, Sarah; Jurjus, Rosalyn A.; Larsen, Melinda

    2011-01-01

    Corneal scarring is a major cause of blindness worldwide and can result from the deposition of abnormal amounts of collagen fibers lacking the correct size and spacing required to produce a clear cornea. Collagen fiber formation requires a preformed fibronectin (FN) matrix. We demonstrate that the loss of syndecan1 (sdc1) in corneal stromal cells (CSC) impacts cell migration rates, the sizes and composition of focal and fibrillar adhesions, the activation of integrins, and the assembly of fibronectin into fibrils. Integrin and fibronectin expression are not altered on sdc1 null CSCs. Cell adhesion, spreading, and migration studies using low compared to high concentrations of FN and collagen I (CNI) or vitronectin (VN) with and without activation of integrins by manganese chloride show that the impact of sdc1 depletion on integrin activation varies depending on the integrin-mediated activity evaluated. Differences in FN-fibrillogenesis and migration in sdc1 null CSCs are reversed by addition of manganese chloride but cell spreading differences remain. To determine if our findings on sdc1 were specific to the cornea, we compared the phenotypes of sdc1 null dermal fibroblasts with those of CSCs. We found that without sdc1, both cell types migrate faster; however, cell-type specific differences in FN expression and its assembly into fibrils exist between these two cell types. Together, our data demonstrate that sdc1 functions to regulate integrin activity in multiple cell types. Loss of sdc1-mediated integrin function results in cell-type specific differences in matrix assembly. A better understanding of how different cell types regulate FN fibril formation via syndecans and integrins will lead to better treatments for scarring and fibrosis. PMID:20580707

  1. Probing cell migration in confined environments by plasma lithography.

    PubMed

    Junkin, Michael; Wong, Pak Kin

    2011-03-01

    Cellular processes are regulated by various mechanical and physical factors in their local microenvironment such as geometric confinements, cell-substrate interactions, and cell-cell contact. Systematic elucidation of these regulatory mechanisms is crucial for fundamental understanding of cell biology and for rational design of biomedical devices and regenerative medicine. Here, we report a generally applicable plasma lithography technique, which performs selective surface functionalization on large substrate areas, for achieving long-term, stable confinements with length scales from 100 nm to 1 cm toward the investigation of cell-microenvironment interactions. In particular, we applied plasma lithography for cellular confinement of neuroblastomas, myoblasts, endothelial cells, and mammary gland epithelial cells, and examined the motion of mouse embryonic fibroblasts in directionality-confined environments for studying the effect of confinements on migratory behavior. In conjunction with live cell imaging, the distance traveled, velocity, and angular motion of individual cells and collective cell migration behaviors were measured in confined environments with dimensions comparable to a cell. A critical length scale that a cell could conceivably occupy and migrate to was also identified by investigating the behaviors of cells using confined environments with subcellular length scales.

  2. A new role for GABA: inhibition of tumor cell migration.

    PubMed

    Ortega, Arturo

    2003-04-01

    GABA, the main inhibitory neurotransmitter in the vertebrate brain, participates outside the CNS in diverse functions such as platelet aggregation and the acrosomal reaction in spermatozoa. A recent study now demonstrates that GABA inhibits the migration of colon carcinoma cells, paving the way to the development of specific pharmacological agents that delay or inhibit invasion and metastasis of various cancer types.

  3. A Cilia Independent Role of Ift88/Polaris during Cell Migration.

    PubMed

    Boehlke, Christopher; Janusch, Heike; Hamann, Christoph; Powelske, Christian; Mergen, Miriam; Herbst, Henriette; Kotsis, Fruzsina; Nitschke, Roland; Kuehn, E Wolfgang

    2015-01-01

    Ift88 is a central component of the intraflagellar transport (Ift) complex B, essential for the building of cilia and flagella from single cell organisms to mammals. Loss of Ift88 results in the absence of cilia and causes left-right asymmetry defects, disordered Hedgehog signaling, and polycystic kidney disease, all of which are explained by aberrant ciliary function. In addition, a number of extraciliary functions of Ift88 have been described that affect the cell-cycle, mitosis, and targeting of the T-cell receptor to the immunological synapse. Similarly, another essential ciliary molecule, the kinesin-2 subunit Kif3a, which transports Ift-B in the cilium, affects microtubule (MT) dynamics at the leading edge of migrating cells independently of cilia. We now show that loss of Ift88 impairs cell migration irrespective of cilia. Ift88 is required for the polarization of migrating MDCK cells, and Ift88 depleted cells have fewer MTs at the leading edge. Neither MT dynamics nor MT nucleation are dependent on Ift88. Our findings dissociate the function of Ift88 from Kif3a outside the cilium and suggest a novel extraciliary function for Ift88. Future studies need to address what unifying mechanism underlies the different extraciliary functions of Ift88. PMID:26465598

  4. A Cilia Independent Role of Ift88/Polaris during Cell Migration

    PubMed Central

    Hamann, Christoph; Powelske, Christian; Mergen, Miriam; Herbst, Henriette; Kotsis, Fruzsina; Nitschke, Roland; Kuehn, E. Wolfgang

    2015-01-01

    Ift88 is a central component of the intraflagellar transport (Ift) complex B, essential for the building of cilia and flagella from single cell organisms to mammals. Loss of Ift88 results in the absence of cilia and causes left-right asymmetry defects, disordered Hedgehog signaling, and polycystic kidney disease, all of which are explained by aberrant ciliary function. In addition, a number of extraciliary functions of Ift88 have been described that affect the cell-cycle, mitosis, and targeting of the T-cell receptor to the immunological synapse. Similarly, another essential ciliary molecule, the kinesin-2 subunit Kif3a, which transports Ift-B in the cilium, affects microtubule (MT) dynamics at the leading edge of migrating cells independently of cilia. We now show that loss of Ift88 impairs cell migration irrespective of cilia. Ift88 is required for the polarization of migrating MDCK cells, and Ift88 depleted cells have fewer MTs at the leading edge. Neither MT dynamics nor MT nucleation are dependent on Ift88. Our findings dissociate the function of Ift88 from Kif3a outside the cilium and suggest a novel extraciliary function for Ift88. Future studies need to address what unifying mechanism underlies the different extraciliary functions of Ift88. PMID:26465598

  5. Endogenous electric fields as guiding cue for cell migration

    PubMed Central

    Funk, Richard H. W.

    2015-01-01

    This review covers two topics: (1) “membrane potential of low magnitude and related electric fields (bioelectricity)” and (2) “cell migration under the guiding cue of electric fields (EF).”Membrane potentials for this “bioelectricity” arise from the segregation of charges by special molecular machines (pumps, transporters, ion channels) situated within the plasma membrane of each cell type (including eukaryotic non-neural animal cells). The arising patterns of ion gradients direct many cell- and molecular biological processes such as embryogenesis, wound healing, regeneration. Furthermore, EF are important as guiding cues for cell migration and are often overriding chemical or topographic cues. In osteoblasts, for instance, the directional information of EF is captured by charged transporters on the cell membrane and transferred into signaling mechanisms that modulate the cytoskeleton and motor proteins. This results in a persistent directional migration along an EF guiding cue. As an outlook, we discuss questions concerning the fluctuation of EF and the frequencies and mapping of the “electric” interior of the cell. Another exciting topic for further research is the modeling of field concepts for such distant, non-chemical cellular interactions. PMID:26029113

  6. Exo70 Generates Membrane Curvature for Morphogenesis and Cell Migration

    PubMed Central

    Zhao, Yuting; Liu, Jianglan; Yang, Changsong; Capraro, Benjamin R.; Baumgart, Tobias; Bradley, Ryan P.; Ramakrishnan, N.; Xu, Xiaowei; Radhakrishnan, Ravi; Svitkina, Tatyana; Guo, Wei

    2013-01-01

    Dynamic shape changes of the plasma membrane are fundamental to many processes ranging from morphogenesis and cell migration to phagocytosis and viral propagation. Here we demonstrate that Exo70, a component of the exocyst complex, induces tubular membrane invaginations towards the lumen of synthetic vesicles in vitro and generates protrusions on the surface of cells. Biochemical analyses using Exo70 mutants and independent molecular dynamics simulations based on Exo70 structure demonstrate that Exo70 generates negative membrane curvature through an oligomerization-based mechanism. In cells, the membrane-deformation function of Exo70 is required for protrusion formation and directional cell migration. Exo70 thus represents a membrane-bending protein that may couple actin dynamics and plasma membrane remodeling for morphogenesis. PMID:23948253

  7. Hemoglobin regulates the migration of glioma cells along poly(ε-caprolactone)-aligned nanofibers.

    PubMed

    Roth, Alexander D; Elmer, Jacob; Harris, David R; Huntley, Joseph; Palmer, Andre F; Nelson, Tyler; Johnson, Jed K; Xue, Ruipeng; Lannutti, John J; Viapiano, Mariano S

    2014-01-01

    Aligned fibers have been shown to facilitate cell migration in the direction of fiber alignment while oxygen (O2 )-carrying solutions improve the metabolism of cells in hypoxic culture. Therefore, U251 aggregate migration on poly(ε-caprolactone) (PCL)-aligned fibers was studied in cell culture media supplemented with the O2 storage and transport protein hemoglobin (Hb) obtained from bovine, earthworm and human sources at concentrations ranging from 0 to 5 g/L within a cell culture incubator exposed to O2 tensions ranging from 1 to 19% O2 . Individual cell migration was quantified using a wound healing assay. In addition, U251 cell aggregates were developed and aggregate dispersion/cell migration quantified on PCL-aligned fibers. The results of this work show that the presence of bovine or earthworm Hb improved individual cell viability at 1% O2 , while human Hb adversely affected cell viability at increasing Hb concentrations and decreasing O2 levels. The control data suggests that decreasing the O2 tension in the incubator from 5 to 1% O2 decreased aggregate dispersion on the PCL-aligned fibers. However, the addition of bovine Hb at 5% O2 significantly improved aggregate dispersion. At 19% O2 , Hb did not impact aggregate dispersion. Also at 1% O2 , aggregate dispersion appeared to increase in the presence of earthworm Hb, but only at the latter time points. Taken together, these results show that Hb-based O2 carriers can be utilized to improve O2 availability and the migration of glioma spheroids on nanofibers. PMID:25044995

  8. IAP proteins: regulators of cell migration and development.

    PubMed

    Kenneth, Niall S; Duckett, Colin S

    2012-12-01

    The cytoprotective properties of vertebrate inhibitor of apoptosis (IAP) proteins have been the subject of much study. These proteins have, however, emerged as key signaling intermediates modulating a variety of cellular functions through their ability to act as E3 ubiquitin ligases. This review will focus on the cell death-independent roles of the IAP proteins, focusing on recent reports indicating that c-IAPs and XIAP are key molecules involved in modulating cell migration and development.

  9. Migration of amoeba cells in an electric field

    NASA Astrophysics Data System (ADS)

    Guido, Isabella; Bodenschatz, Eberhard

    2015-03-01

    Exogenous and endogenous electric fields play a role in cell physiology as a guiding mechanism for the orientation and migration of cells. Electrotaxis of living cells has been observed for several cell types, e.g. neurons, fibroblasts, leukocytes, neural crest cells, cancer cells. Dictyostelium discoideum (Dd), an intensively investigated chemotactic model organism, also exhibits a strong electrotactic behavior moving toward the cathode under the influence of electric fields. Here we report experiments on the effects of DC electric fields on the directional migration of Dd cells. We apply the electric field to cells seeded into microfluidic devices equipped with agar bridges to avoid any harmful effects of the electric field on the cells (ions formation, pH changes, etc.) and a constant flow to prevent the build-up of chemical gradient that elicits chemotaxis. Our results show that the cells linearly increase their speed over time when a constant electric field is applied for a prolonged duration (2 hours). This novel phenomenon cannot be attributed to mechanotaxis as the drag force of the electroosmotic flow is too small to produce shear forces that can reorient cells. It is independent of the cellular developmental stage and to our knowledge, it was not observed in chemotaxis. This work is supported by MaxSynBio project of the Max Planck Society.

  10. Divergent behaviors and underlying mechanisms of cell migration and invasion in non-metastatic T24 and its metastatic derivative T24T bladder cancer cell lines.

    PubMed

    Jin, Honglei; Yu, Yonghui; Hu, Young; Lu, Chris; Li, Jingxia; Gu, Jiayan; Zhang, Liping; Huang, Haishan; Zhang, Dongyun; Wu, Xue-Ru; Gao, Jimin; Huang, Chuanshu

    2015-01-01

    Previous studies on cancer cell invasion were primarily focused on its migration because these two events were often considered biologically equivalent. Here we found that T24T cells exhibited higher invasion but lower migration abilities than T24 cells. Expression of Rho-GDPases was much lower and expression of SOD2 was much higher in T24T cells than those in T24 cells. Indeed, knockdown of SOD2 in T24T cells can reverse the cell migration but without affecting cell invasion. We also found that SOD2 inhibited the JNK/c-Jun cascade, and the inhibition of c-Jun activation by ectopic expression of TAM67 impaired Rho-GDPases expression and cell migration in T24T shSOD2 cells. Further, we found that Sp1 can upregulate SOD2 transcription in T24T cells. Importantly, matrix metalloproteinase-2 (MMP-2) was overexpressed in T24T and participated in increasing its invasion, and MMP-2 overexpression was mediated by increasing nuclear transport of nucleolin, which enhanced mmp-2 mRNA stability. Taken together, our study unravels an inverse relationship between cell migration and invasion in human bladder cancer T24T cells and suggests a novel mechanism underlying the divergent roles of SOD2 and MMP-2 in regulating metastatic behaviors of human bladder T24T in cell migration and invasion. PMID:25402510

  11. DAPK loss in colon cancer tumor buds: implications for migration capacity of disseminating tumor cells

    PubMed Central

    Karamitopoulou, Eva; Dawson, Heather; Koelzer, Viktor Hendrik; Agaimy, Abbas; Garreis, Fabian; Söder, Stephan; Laqua, William; Lugli, Alessandro; Hartmann, Arndt; Rau, Tilman T.; Schneider-Stock, Regine

    2015-01-01

    Defining new therapeutic strategies to overcome therapy resistance due to tumor heterogeneity in colon cancer is challenging. One option is to explore the molecular profile of aggressive disseminating tumor cells. The cytoskeleton-associated Death-associated protein kinase (DAPK) is involved in the cross talk between tumor and immune cells at the invasion front of colorectal cancer. Here dedifferentiated tumor cells histologically defined as tumor budding are associated with a high risk of metastasis and poor prognosis. Analyzing samples from 144 colorectal cancer patients we investigated immunhistochemical DAPK expression in different tumor regions such as center, invasion front, and buds. Functional consequences for tumor aggressiveness were studied in a panel of colon tumor cell lines using different migration, wound healing, and invasion assays. DAPK levels were experimentally modified by siRNA transfection and overexpression as well as inhibitor treatments. We found that DAPK expression was reduced towards the invasion front and was nearly absent in tumor buds. Applying the ECIS system with HCT116 and HCT116 stable lentiviral DAPK knock down cells (HCTshDAPK) we identified an important role for DAPK in decreasing the migratory capacity whereas proliferation was not affected. Furthermore, the migration pattern differed with HCTshDAPK cells showing a cluster-like migration of tumor cell groups. DAPK inhibitor treatment revealed that the migration rate was independent of DAPK's catalytic activity. Modulation of DAPK expression level in SW480 and DLD1 colorectal cancer cells significantly influenced wound closure rate. DAPK seems to be a major player that influences the migratory capability of disseminating tumor cells and possibly affects the dynamic interface between pro- and anti-survival factors at the invasion front of colorectal cancer. This interesting and new finding requires further evaluation. PMID:26405175

  12. Protein kinase D2 regulates migration and invasion of U87MG glioblastoma cells in vitro

    SciTech Connect

    Bernhart, Eva; Damm, Sabine; Wintersperger, Andrea; DeVaney, Trevor; Zimmer, Andreas; Raynham, Tony; Ireson, Christopher; Sattler, Wolfgang

    2013-08-01

    Glioblastoma multiforme (GBM) is the most common malignant brain tumor, which, despite combined modality treatment, reoccurs and is invariably fatal for affected patients. Recently, a member of the serine/threonine protein kinase D (PRKD) family, PRKD2, was shown to be a potent mediator of glioblastoma growth. Here we studied the role of PRKD2 in U87MG glioblastoma cell migration and invasion in response to sphingosine-1-phosphate (S1P), an activator of PRKD2 and a GBM mitogen. Time-lapse microscopy demonstrated that random cell migration was significantly diminished in response to PRKD2 silencing. The pharmacological PRKD family inhibitor CRT0066101 decreased chemotactic migration and invasion across uncoated or matrigel-coated Transwell inserts. Silencing of PRKD2 attenuated migration and invasion of U87MG cells even more effectively. In terms of downstream signaling, CRT0066101 prevented PRKD2 autophosphorylation and inhibited p44/42 MAPK and to a smaller extent p54/46 JNK and p38 MAPK activation. PRKD2 silencing impaired activation of p44/42 MAPK and p54/46 JNK, downregulated nuclear c-Jun protein levels and decreased c-Jun{sup S73} phosphorylation without affecting the NFκB pathway. Finally, qPCR array analyses revealed that silencing of PRKD2 downregulates mRNA levels of integrin alpha-2 and -4 (ITGA2 and -4), plasminogen activator urokinase (PLAU), plasminogen activator urokinase receptor (PLAUR), and matrix metallopeptidase 1 (MMP1). Findings of the present study identify PRKD2 as a potential target to interfere with glioblastoma cell migration and invasion, two major determinants contributing to recurrence of glioblastoma after multimodality treatment. Highlights: • Sphingosine-1-phosphate induces glioma cell migration and invasion. • Part of the effects is mediated by protein kinase D2 (PRKD2) activation. • Inactivation of PRKD2 attenuates glioblastoma cell migration and invasion. • Both, RNAi and pharmacological inhibition of PRKD2 inhibits MAPK

  13. Temperature affects the timing of spawning and migration of North Sea mackerel

    NASA Astrophysics Data System (ADS)

    Jansen, Teunis; Gislason, Henrik

    2011-01-01

    Climate change accentuates the need for knowing how temperature impacts the life history and productivity of economically and ecologically important species of fish. We examine the influence of temperature on the timing of the spawning and migrations of North Sea Mackerel using data from larvae CPR surveys, egg surveys and commercial landings from Danish coastal fisheries in the North Sea, Skagerrak, Kattegat and inner Danish waters. The three independent sources of data all show that there is a significant relationship between the timing of spawning and sea surface temperature. Large mackerel are shown to arrive at the feeding areas before and leave later than small mackerel and the sequential appearance of mackerel in each of the feeding areas studied supports the anecdotal evidence for an eastward post-spawning migration. Occasional commercial catches taken in winter in the Sound N, Kattegat and Skagerrak together with catches in the first quarter IBTS survey furthermore indicate some overwintering here. Significant relationships between temperature and North Sea mackerel spawning and migration have not been documented before. The results have implications for mackerel resource management and monitoring. An increase in temperature is likely to affect the timing and magnitude of the growth, recruitment and migration of North Sea mackerel with subsequent impacts on its sustainable exploitation.

  14. Pak3 regulates apical-basal polarity in migrating border cells during Drosophila oogenesis.

    PubMed

    Felix, Martina; Chayengia, Mrinal; Ghosh, Ritabrata; Sharma, Aditi; Prasad, Mohit

    2015-11-01

    Group cell migration is a highly coordinated process that is involved in a number of physiological events such as morphogenesis, wound healing and tumor metastasis. Unlike single cells, collectively moving cells are physically attached to each other and retain some degree of apical-basal polarity during the migratory phase. Although much is known about direction sensing, how polarity is regulated in multicellular movement remains unclear. Here we report the role of the protein kinase Pak3 in maintaining apical-basal polarity in migrating border cell clusters during Drosophila oogenesis. Pak3 is enriched in border cells and downregulation of its function impedes border cell movement. Time-lapse imaging suggests that Pak3 affects protrusive behavior of the border cell cluster, specifically regulating the stability and directionality of protrusions. Pak3 functions downstream of guidance receptor signaling to regulate the level and distribution of F-actin in migrating border cells. We also provide evidence that Pak3 genetically interacts with the lateral polarity marker Scribble and that it regulates JNK signaling in the moving border cells. Since Pak3 depletion results in mislocalization of several apical-basal polarity markers and overexpression of Jra rescues the polarity of the Pak3-depleted cluster, we propose that Pak3 functions through JNK signaling to modulate apical-basal polarity of the migrating border cell cluster. We also observe loss of apical-basal polarity in Rac1-depleted border cell clusters, suggesting that guidance receptor signaling functions through Rac GTPase and Pak3 to regulate the overall polarity of the cluster and mediate efficient collective movement of the border cells to the oocyte boundary.

  15. T-cell Migration, Search Strategies and Mechanisms

    PubMed Central

    Krummel, Matthew F; Bartumeus, Frederic; Gérard, Audrey

    2016-01-01

    T cell migration is essential for T cell responses, allowing for detection of cognate antigen at the surface of an Antigen-Presenting Cell (APC) and for interactions with other cells involved in the immune response. Although appearing random, growing evidence supports that T cell motility patterns are strategic and governed by mechanisms that are optimized for both activation-stage and environment-specific attributes. In this Opinion Article, we will discuss how to understand the combined effects of T cell- intrinsic and -extrinsic forces upon these motility patterns when viewed in highly complex tissues filled with other cells involved in parallel motility. In particular, we will examine how insights from ‘search theory’ describe T cell movement across exploitation-exploration gradients, in the context of activation versus effector function and in the context of lymph nodes versus peripheral tissues. PMID:26852928

  16. Neutrophil motility in extracellular matrix gels: mesh size and adhesion affect speed of migration.

    PubMed Central

    Kuntz, R M; Saltzman, W M

    1997-01-01

    Polymorphonuclear leukocyte (PMN) migration through tissue extracellular space is an essential step in the inflammatory response, but little is known about the factors influencing PMN migration through gels of extracellular matrix (ECM). In this study, PMN migration within reconstituted gels containing collagen type I or collagen type I supplemented with laminin, fibronectin, or heparin was measured by quantitative direct visualization, resulting in a random motility coefficient (mum a quantitative index for rate of cell dispersion) for the migrating cell population. The random motility coefficient in unsupplemented collagen (0.4 mg/ml) gels was approximately 9 x 10(-9) cm2/s. Supplementing gels with heparin or fibronectin produced a significant decrease in mu, even at the lowest concentrations studied (1 microgram/ml fibronectin or 0.4 microgram/ml heparin). At least 100 micrograms/ml of laminin, or 20% of the total gel protein, was required to produce a similar decrease in mu. Scanning electron microscopy revealed two different gel morphologies: laminin or fibronectin appeared to coat the 150-nm collagen fibers whereas heparin appeared to induce fiber bundle formation and, therefore, larger interstitial spaces. The decrease in mu observed in heparin-supplemented gels correlated with the increased mesh size of the fiber network, but the difference observed in mu for fibronectin- and laminin-supplemented gels did not correlate with either mesh size or the mechanical properties of the gel, as determined by rheological measurements. However, PMNs adhered to fibronectin-coated surfaces in greater numbers than to collagen- or laminin-coated surfaces, suggesting that changes in cell adhesion to protein fibers can also produce significant changes in cell motility within an ECM gel. Images FIGURE 2 FIGURE 3 FIGURE 9 PMID:9138592

  17. Chemokine-guided cell migration and motility in zebrafish development.

    PubMed

    Bussmann, Jeroen; Raz, Erez

    2015-05-12

    Chemokines are vertebrate-specific, structurally related proteins that function primarily in controlling cell movements by activating specific 7-transmembrane receptors. Chemokines play critical roles in a large number of biological processes and are also involved in a range of pathological conditions. For these reasons, chemokines are at the focus of studies in developmental biology and of clinically oriented research aimed at controlling cancer, inflammation, and immunological diseases. The small size of the zebrafish embryos, their rapid external development, and optical properties as well as the large number of eggs and the fast expansion in genetic tools available make this model an extremely useful one for studying the function of chemokines and chemokine receptors in an in vivo setting. Here, we review the findings relevant to the role that chemokines play in the context of directed single-cell migration, primarily in neutrophils and germ cells, and compare it to the collective cell migration of the zebrafish lateral line. We present the current knowledge concerning the formation of the chemokine gradient, its interpretation within the cell, and the molecular mechanisms underlying the cellular response to chemokine signals during directed migration.

  18. Optogenetic approaches to cell migration and beyond

    PubMed Central

    Weitzman, Matthew; Hahn, Klaus M.

    2014-01-01

    Optogenetics, the use of genetically encoded tools to control protein function with light, can generate localized changes in signaling within living cells and animals. For years it has been focused on channel proteins for neurobiology, but has recently expanded to cover many different types of proteins, using a broad array of different protein engineering approaches. These methods have largely been directed at proteins involved in motility, cytoskeletal regulation and gene expression. This review provides a survey of non-channel proteins that have been engineered for optogenetics. Existing molecules are used to illustrate the advantages and disadvantages of the many imaginative new approaches that the reader can use to create light-controlled proteins. PMID:25216352

  19. MIG6 is MEK-regulated and affects EGF-induced migration in mutant NRAS melanoma

    PubMed Central

    Vu, Ha Linh; Rosenbaum, Sheera; Capparelli, Claudia; Purwin, Timothy J.; Davies, Michael A.; Berger, Adam C.; Aplin, Andrew E.

    2015-01-01

    Activating mutations in NRAS are frequent driver events in cutaneous melanoma. NRAS is a GTP-binding protein, whose most well-characterized downstream effector is RAF leading to activation of MEK-ERK1/2 signaling. While there are no FDA-approved targeted therapies for melanoma patients with a primary mutation in NRAS, one form of targeted therapy that has been explored is MEK inhibition. In clinical trials, MEK inhibitors have shown disappointing efficacy in mutant NRAS patients, the reasons for which are unclear. To explore the effects of MEK inhibitors in mutant NRAS melanoma, we utilized a high-throughput reverse-phase protein array (RPPA) platform to identify signaling alterations. RPPA analysis of phospho-proteomic changes in mutant NRAS melanoma in response to trametinib indicated a compensatory increase in AKT signaling and decreased expression of mitogen-inducible gene 6 (MIG6), a negative regulator of EGFR/ERBB receptors. MIG6 expression did not alter the growth or survival properties of mutant NRAS melanoma cells. Rather, we identified a role for MIG6 as a negative regulator of EGF-induced signaling and cell migration and invasion. In MEK inhibited cells, further depletion of MIG6 increased migration and invasion, whereas MIG6 expression decreased these properties. Therefore, a decrease in MIG6 may promote the migration and invasiveness of MEK-inhibited mutant NRAS melanoma especially in response to EGF stimulation. PMID:26967478

  20. Anandamide inhibits adhesion and migration of breast cancer cells

    SciTech Connect

    Grimaldi, Claudia; Pisanti, Simona; Laezza, Chiara; Malfitano, Anna Maria; Santoro, Antonietta; Vitale, Mario; Caruso, Maria Gabriella; Notarnicola, Maria; Iacuzzo, Irma; Portella, Giuseppe; Di Marzo, Vincenzo . E-mail: vdimarzo@icmib.na.cnr.it; Bifulco, Maurizio . E-mail: maubiful@unina.it

    2006-02-15

    The endocannabinoid system regulates cell proliferation in human breast cancer cells. We reasoned that stimulation of cannabinoid CB{sub 1} receptors could induce a non-invasive phenotype in breast mtastatic cells. In a model of metastatic spreading in vivo, the metabolically stable anandamide analogue, 2-methyl-2'-F-anandamide (Met-F-AEA), significantly reduced the number and dimension of metastatic nodes, this effect being antagonized by the selective CB{sub 1} antagonist SR141716A. In MDA-MB-231 cells, a highly invasive human breast cancer cell line, and in TSA-E1 cells, a murine breast cancer cell line, Met-F-AEA inhibited adhesion and migration on type IV collagen in vitro without modifying integrin expression: both these effects were antagonized by SR141716A. In order to understand the molecular mechanism involved in these processes, we analyzed the phosphorylation of FAK and Src, two tyrosine kinases involved in migration and adhesion. In Met-F-AEA-treated cells, we observed a decreased tyrosine phosphorylation of both FAK and Src, this effect being attenuated by SR141716A. We propose that CB{sub 1} receptor agonists inhibit tumor cell invasion and metastasis by modulating FAK phosphorylation, and that CB{sub 1} receptor activation might represent a novel therapeutic strategy to slow down the growth of breast carcinoma and to inhibit its metastatic diffusion in vivo.

  1. The Origin And Migration Of Primordial Germ Cells In Sturgeons

    PubMed Central

    Saito, Taiju; Pšenička, Martin; Goto, Rie; Adachi, Shinji; Inoue, Kunio; Arai, Katsutoshi; Yamaha, Etsuro

    2014-01-01

    Primordial germ cells (PGCs) arise elsewhere in the embryo and migrate into developing gonadal ridges during embryonic development. In several model animals, formation and migration patterns of PGCs have been studied, and it is known that these patterns vary. Sturgeons (genus Acipenser) have great potential for comparative and evolutionary studies of development. Sturgeons belong to the super class Actinoptergii, and their developmental pattern is similar to that of amphibians, although their phylogenetic position is an out-group to teleost fishes. Here, we reveal an injection technique for sturgeon eggs allowing visualization of germplasm and PGCs. Using this technique, we demonstrate that the PGCs are generated at the vegetal pole of the egg and they migrate on the yolky cell mass toward the gonadal ridge. We also provide evidence showing that PGCs are specified by inheritance of maternally supplied germplasm. Furthermore, we demonstrate that the migratory mechanism is well-conserved between sturgeon and other remotely related teleosts, such as goldfish, by a single PGCs transplantation (SPT) assay. The mode of PGCs specification in sturgeon is similar to that of anurans, but the migration pattern resembles that of teleosts. PMID:24505272

  2. Cell migration and antigen capture are antagonistic processes coupled by myosin II in dendritic cells

    PubMed Central

    Chabaud, Mélanie; Heuzé, Mélina L.; Bretou, Marine; Vargas, Pablo; Maiuri, Paolo; Solanes, Paola; Maurin, Mathieu; Terriac, Emmanuel; Le Berre, Maël; Lankar, Danielle; Piolot, Tristan; Adelstein, Robert S.; Zhang, Yingfan; Sixt, Michael; Jacobelli, Jordan; Bénichou, Olivier; Voituriez, Raphaël; Piel, Matthieu; Lennon-Duménil, Ana-Maria

    2015-01-01

    The immune response relies on the migration of leukocytes and on their ability to stop in precise anatomical locations to fulfil their task. How leukocyte migration and function are coordinated is unknown. Here we show that in immature dendritic cells, which patrol their environment by engulfing extracellular material, cell migration and antigen capture are antagonistic. This antagonism results from transient enrichment of myosin IIA at the cell front, which disrupts the back-to-front gradient of the motor protein, slowing down locomotion but promoting antigen capture. We further highlight that myosin IIA enrichment at the cell front requires the MHC class II-associated invariant chain (Ii). Thus, by controlling myosin IIA localization, Ii imposes on dendritic cells an intermittent antigen capture behaviour that might facilitate environment patrolling. We propose that the requirement for myosin II in both cell migration and specific cell functions may provide a general mechanism for their coordination in time and space. PMID:26109323

  3. Actein Inhibits Cell Proliferation and Migration in Human Osteosarcoma

    PubMed Central

    Chen, Zhi; Wu, Jingdong; Guo, Qinghao

    2016-01-01

    Background Osteosarcoma is one of the most common malignant bone cancers worldwide. Although the traditional chemotherapies have made some progression in the past decades, the mortality of osteosarcoma in children and adolescent is very high. Herein, the role of actein in osteosarcoma was explored. Material/Methods Cell viability assay was performed in osteosarcoma cell lines 143B and U2OS. Colony formation analysis was included when cells were treated with different doses of actin. Cell cycle assay was conducted to further examine the role of actein. Cell apoptotic rate and the relative activities of caspase-3, caspase-8, and caspase-9 were detected in 143B and U2OS osteosarcoma cells. Moreover, transwell assays were used to explore the effects of actein on cell metastasis. Results Actein significantly inhibited osteosarcoma cell viability in a time- and dose-dependent manner. Actein also dramatically suppressed the colony formation ability in osteosarcoma143B and U2OS cells. It was revealed that osteosarcoma cells were arrested in G0/G1 phase in the cell cycle progression and induced to apoptosis by administration of actein. The activities of pro-apoptotic factors such as caspase-3 and caspase-9 were significantly increased by actein. Furthermore, administration of actein decreased cell migrated and invasive abilities in both 143B and U2OS cell lines. Conclusions Actein inhibits tumor growth by inducing cell apoptosis in osteosarcoma. The inhibitive roles of actein in cell proliferation, migration and invasion suggest that actein may serve as a potential therapeutic agent in the treatment of osteosarcoma. PMID:27173526

  4. Downregulation of coding transmembrane protein 35 gene inhibits cell proliferation, migration and cell cycle arrest in osteosarcoma cells

    PubMed Central

    Huang, Yinjun; Zhao, Shichang; Zhang, Yadong; Zhang, Changqing; Li, Xiaolin

    2016-01-01

    Osteosarcoma (OSA) is the most common primary tumor of the bone. Resistance to chemotherapy and the fast rapid development of metastatic lesions are major issues responsible for treatment failure and poor survival rates in OSA patients. Tetraspanins comprise a family of transmembrane receptor glycoproteins that affect tumor cell migration through tetraspanin-integrin interaction. The present study focused on a four-pass transmembrane protein gene, transmembrane protein 35 (TMEM35) gene, and examined its role in the growth, migration and cell cycle progression of OSA cells. In addition, the study discussed whether the TMEM35 gene, which encodes the TMEM35 protein, may be a potential therapeutic target for OSA. In the current study, reverse transcription-quantitative polymerase chain reaction was performed to examine TMEM35 expression in OSA and matched healthy tissues. Small interfering RNAs (siRNAs) were transfected into SaOS2 and U2OS cells to knockdown the TMEM35 expression. Soft-agar colony formation assay was performed to evaluate cell growth, and cell cycle progression was analyzed by flow cytometry. Wound-healing and Boyden chamber assays were also performed to investigate cell invasion and migration by the SaOS2 and U2OS cells. TMEM35 protein was analyzed in a functional protein interaction networks database (STRING database) to predict the functional interaction partner proteins of TMEM35. The results indicated that TMEM35 was abnormally expressed in OSA tissues. Of the 37 examined patients, TMEM35 expression was significantly increased in the OSA tissues of 24 patients (64.86%; P<0.05), when compared with the expression in normal tissues. Furthermore, TMEM35 knockdown following transfection with siRNAs inhibited the colony formation ability of SaOS2 and U2OS cells in soft agar. Flow cytometric analysis also revealed that TMEM35 knockdown by RNA interference may result in G1 phase arrest and a decreased cell population at the S phase. TMEM35 knockdown

  5. Migration of Drosophila intestinal stem cells across organ boundaries

    PubMed Central

    Takashima, Shigeo; Paul, Manash; Aghajanian, Patrick; Younossi-Hartenstein, Amelia; Hartenstein, Volker

    2013-01-01

    All components of the Drosophila intestinal tract, including the endodermal midgut and ectodermal hindgut/Malpighian tubules, maintain populations of dividing stem cells. In the midgut and hindgut, these stem cells originate from within larger populations of intestinal progenitors that proliferate during the larval stage and form the adult intestine during metamorphosis. The origin of stem cells found in the excretory Malpighian tubules (‘renal stem cells’) has not been established. In this paper, we investigate the migration patterns of intestinal progenitors that take place during metamorphosis. Our data demonstrate that a subset of adult midgut progenitors (AMPs) move posteriorly to form the adult ureters and, consecutively, the renal stem cells. Inhibiting cell migration by AMP-directed expression of a dominant-negative form of Rac1 protein results in the absence of stem cells in the Malpighian tubules. As the majority of the hindgut progenitor cells migrate posteriorly and differentiate into hindgut enterocytes, a group of the progenitor cells, unexpectedly, invades anteriorly into the midgut territory. Consequently, these progenitor cells differentiate into midgut enterocytes. The midgut determinant GATAe is required for the differentiation of midgut enterocytes derived from hindgut progenitors. Wingless signaling acts to balance the proportion of hindgut progenitors that differentiate as midgut versus hindgut enterocytes. Our findings indicate that a stable boundary between midgut and hindgut/Malpighian tubules is not established during early embryonic development; instead, pluripotent progenitor populations cross in between these organs in both directions, and are able to adopt the fate of the organ in which they come to reside. PMID:23571215

  6. Early-life serotonin dysregulation affects the migration and positioning of cortical interneuron subtypes

    PubMed Central

    Frazer, S; Otomo, K; Dayer, A

    2015-01-01

    Early-life deficiency of the serotonin transporter (SERT) gives rise to a wide range of psychiatric-relevant phenotypes; however, the molecular and cellular targets of serotonin dyregulation during neural circuit formation remain to be identified. Interestingly, migrating cortical interneurons (INs) derived from the caudal ganglionic eminence (CGE) have been shown to be more responsive to serotonin-mediated signalling compared with INs derived from the medial ganglionic eminence (MGE). Here we investigated the impact of early-life SERT deficiency on the migration and positioning of CGE-derived cortical INs in SERT-ko mice and in mice exposed to the SERT inhibitor fluoxetine during the late embryonic period. Using confocal time-lapse imaging and microarray-based expression analysis we found that genetic and pharmacological SERT deficiency significantly increased the migratory speed of CGE-derived INs and affected transcriptional programmes regulating neuronal migration. Postnatal studies revealed that SERT deficiency altered the cortical laminar distribution of subtypes of CGE-derived INs but not MGE-derived INs. More specifically, we found that the distribution of vasointestinal peptide (VIP)-expressing INs in layer 2/3 was abnormal in both genetic and pharmacological SERT-deficiency models. Collectively, these data indicate that early-life SERT deficiency has an impact on the migration and molecular programmes of CGE-derived INs, thus leading to specific alterations in the positioning of VIP-expressing INs. These data add to the growing evidence that early-life serotonin dysregulation affects cortical microcircuit formation and contributes to the emergence of psychiatric-relevant phenotypes. PMID:26393490

  7. Early-life serotonin dysregulation affects the migration and positioning of cortical interneuron subtypes.

    PubMed

    Frazer, S; Otomo, K; Dayer, A

    2015-09-22

    Early-life deficiency of the serotonin transporter (SERT) gives rise to a wide range of psychiatric-relevant phenotypes; however, the molecular and cellular targets of serotonin dyregulation during neural circuit formation remain to be identified. Interestingly, migrating cortical interneurons (INs) derived from the caudal ganglionic eminence (CGE) have been shown to be more responsive to serotonin-mediated signalling compared with INs derived from the medial ganglionic eminence (MGE). Here we investigated the impact of early-life SERT deficiency on the migration and positioning of CGE-derived cortical INs in SERT-ko mice and in mice exposed to the SERT inhibitor fluoxetine during the late embryonic period. Using confocal time-lapse imaging and microarray-based expression analysis we found that genetic and pharmacological SERT deficiency significantly increased the migratory speed of CGE-derived INs and affected transcriptional programmes regulating neuronal migration. Postnatal studies revealed that SERT deficiency altered the cortical laminar distribution of subtypes of CGE-derived INs but not MGE-derived INs. More specifically, we found that the distribution of vasointestinal peptide (VIP)-expressing INs in layer 2/3 was abnormal in both genetic and pharmacological SERT-deficiency models. Collectively, these data indicate that early-life SERT deficiency has an impact on the migration and molecular programmes of CGE-derived INs, thus leading to specific alterations in the positioning of VIP-expressing INs. These data add to the growing evidence that early-life serotonin dysregulation affects cortical microcircuit formation and contributes to the emergence of psychiatric-relevant phenotypes.

  8. Nifedipine Promotes the Proliferation and Migration of Breast Cancer Cells

    PubMed Central

    Guo, Dong-Qing; Zhang, Hao; Tan, Sheng-Jiang; Gu, Yu-Chun

    2014-01-01

    Nifedipine is widely used as a calcium channel blocker (CCB) to treat angina and hypertension,but it is controversial with respect the risk of stimulation of cancers. In this study, we demonstrated that nifedipine promoted the proliferation and migration of breast cancer cells both invivo and invitro. However, verapamil, another calcium channel blocker, didn’t exert the similar effects. Nifedipine and high concentration KCl failed to alter the [Ca2+]i in MDA-MB-231 cells, suggesting that such nifedipine effect was not related with calcium channel. Moreover, nifedipine decreased miRNA-524-5p, resulting in the up-regulation of brain protein I3 (BRI3). Erk pathway was consequently activated and led to the proliferation and migration of breast cancer cells. Silencing BRI3 reversed the promoting effect of nifedipine on the breast cancer. In a summary, nifedipine stimulated the proliferation and migration of breast cancer cells via the axis of miRNA-524-5p-BRI3–Erk pathway independently of its calcium channel-blocking activity. Our findings highlight that nifedipine but not verapamil is conducive for breast cancer growth and metastasis, urging that the caution should be taken in clinic to prescribe nifedipine to women who suffering both hypertension and breast cancer, and hypertension with a tendency in breast cancers. PMID:25436889

  9. SENP1 regulates cell migration and invasion in neuroblastoma.

    PubMed

    Xiang-Ming, Yan; Zhi-Qiang, Xu; Ting, Zhang; Jian, Wang; Jian, Pan; Li-Qun, Yuan; Ming-Cui, Fu; Hong-Liang, Xia; Xu, Cao; Yun, Zhou

    2016-05-01

    Neuroblastoma (NB) is an embryonic solid tumor derived from precursor cells of the sympathetic nervous system, and accounts for 11% of childhood cancers and around 15% of cancer deaths in children. SUMOylation and deSUMOylation are dynamic mechanisms regulating a spectrum of protein activities. The SUMO proteases (SENP) remove SUMO conjugate from proteins, and their expression is deregulated in diverse cancers. However, nothing is known about the role of SENPs in NBL. In the present study, we found that SENP1 expression was significantly high in metastatic NB tissues compared with primary NB tissues. Overexpression of SENP1 promoted NB cells migration and invasion. Inhibition of SENP1 could significantly suppress NB cell migration and invasion. Moreover, we found that SENP1 could regulate the expression of CDH1, MMP9, and MMP2. In summary, the data presented here indicate a significant role of SENP1 in the regulation of cell migration and invasion in NB and suppress SENP1 expression as promising candidates for novel treatment strategies of NB.

  10. Promotion of cell migration by neural cell adhesion molecule (NCAM) is enhanced by PSA in a polysialyltransferase-specific manner.

    PubMed

    Guan, Feng; Wang, Xin; He, Fa

    2015-01-01

    Neural cell adhesion molecule 140 (NCAM-140) is a glycoprotein and always highly polysialylated in cancer. Functions of polysialic acid (PSA) that binds to N-glycan termini on NCAM remain unclear. ldlD-14 cells, a CHO cell mutant deficient in UDP-Gal 4-epimerase, are useful for structural and functional studies of Gal-containing glycoproteins because their abnormal glycosylation can be converted to normal status by exogenous addition of galactose (Gal). We cloned the genes for NCAM-140 and for polysialyltransferases STX and PST (responsible for PSA synthesis) from normal murine mammary gland epithelial (NMuMG) cells and transfected them into ldlD-14 and human breast cancer cells MCF-7. The effect of PSA on NCAM-mediated cell proliferation, motility, migration and adhesion was studied. We found that NCAM-140 significantly promoted cell proliferation, motility and migration, while polysialylation of NCAM-140 catalyzed by STX, but not by PST, enhanced NCAM-mediated cell migration, but not cell proliferation or motility. In addition, PSA catalyzed by different polysialyltransferases affected the adhesion of NCAM to different extracellular matrix (ECM) components. PMID:25885924

  11. Monocyte chemoattractant protein-1 affects migration of hippocampal neural progenitors following status epilepticus in rats

    PubMed Central

    2013-01-01

    Background Epilepsy is a common brain disorder characterized by a chronic predisposition to generate spontaneous seizures. The mechanisms for epilepsy formation remain unknown. A growing body of evidence suggests the involvement of inflammatory processes in epileptogenesis. In the present study, we investigated the involvement of monocyte chemoattractant protein-1 (MCP-1) in aberrant migration of hippocampal progenitors in rats after the insult of status epilepticus (SE). Methods SE was induced with pilocarpine in Sprague–Dawley rats. Transcriptional expression of MCP-1 in the dentate gyrus (DG) was measured using quantitative real-time PCR. From 1 to 28 days after SE, the temporal profiles of MCP-1 protein expression in DG were evaluated using enzyme-linked immunosorbent assay. Chemokine (C-C motif) receptor 2 (CCR2) expression in doublecortin-positive neuronal progenitors was examined using double-labeling immunohistochemistry. The involvement of MCP-1/CCR2 signaling in aberrant neuronal progenitor migration in the epileptic hippocampus was assessed in the SE rats using a CCR2 antagonist, RS102895, and the ectopic migration of neuronal progenitors was determined using Prox1/doublecortin double immunostaining. Results After SE, MCP-1 gene was significantly upregulated and its corresponding protein expression in the DG was significantly increased on days 1 and 3. Some hilar ectopic progenitor cells of SE rats expressed the MCP-1 receptor, CCR2. Notably, the ectopic migration of neuronal progenitors into hilus was attenuated by a blockade of the MCP-1/CCR2 interaction with a selective CCR2 inhibitor, RS102895. Conclusions An increase in dentate MCP-1 is associated with seizure-induced aberrant migration of neuronal progenitors through the interaction with CCR2. The upregulation of MCP-1 after an insult of SE may play a role in the generation of epilepsy. PMID:23339567

  12. Capturing relevant extracellular matrices for investigating cell migration

    PubMed Central

    Keely, Patricia; Nain, Amrinder

    2015-01-01

    Much progress in understanding cell migration has been determined by using classic two-dimensional (2D) tissue culture platforms. However, increasingly, it is appreciated that certain properties of cell migration in vivo are not represented by strictly 2D assays. There is much interest in creating relevant three-dimensional (3D) culture environments and engineered platforms to better represent features of the extracellular matrix and stromal microenvironment that are not captured in 2D platforms. Important to this goal is a solid understanding of the features of the extracellular matrix—composition, stiffness, topography, and alignment—in different tissues and disease states and the development of means to capture these features PMID:26918156

  13. Capsaicin modulates proliferation, migration, and activation of hepatic stellate cells.

    PubMed

    Bitencourt, Shanna; Mesquita, Fernanda; Basso, Bruno; Schmid, Júlia; Ferreira, Gabriela; Rizzo, Lucas; Bauer, Moises; Bartrons, Ramon; Ventura, Francesc; Rosa, Jose Luis; Mannaerts, Inge; van Grunsven, Leo Adrianus; Oliveira, Jarbas

    2014-03-01

    Capsaicin, the active component of chili pepper, has been reported to have antiproliferative and anti-inflammatory effects on a variety of cell lines. In the current study, we aimed to investigate the effects of capsaicin during HSC activation and maintenance. Activated and freshly isolated HSCs were treated with capsaicin. Proliferation was measured by incorporation of EdU. Cell cycle arrest and apoptosis were investigated using flow cytometry. The migratory response to chemotactic stimuli was evaluated by a modified Boyden chamber assay. Activation markers and inflammatory cytokines were determined by qPCR, immunocytochemistry, and flow cytometry. Our results show that capsaicin reduces HSC proliferation, migration, and expression of profibrogenic markers of activated and primary mouse HSCs. In conclusion, the present study shows that capsaicin modulates proliferation, migration, and activation of HSC in vitro. PMID:23955514

  14. Epithelial bridges maintain tissue integrity during collective cell migration

    NASA Astrophysics Data System (ADS)

    Vedula, Sri Ram Krishna; Hirata, Hiroaki; Nai, Mui Hoon; Brugués, Agustí; Toyama, Yusuke; Trepat, Xavier; Lim, Chwee Teck; Ladoux, Benoit

    2014-01-01

    The ability of skin to act as a barrier is primarily determined by the efficiency of skin cells to maintain and restore its continuity and integrity. In fact, during wound healing keratinocytes migrate collectively to maintain their cohesion despite heterogeneities in the extracellular matrix. Here, we show that monolayers of human keratinocytes migrating along functionalized micropatterned surfaces comprising alternating strips of extracellular matrix (fibronectin) and non-adherent polymer form suspended multicellular bridges over the non-adherent areas. The bridges are held together by intercellular adhesion and are subjected to considerable tension, as indicated by the presence of prominent actin bundles. We also show that a model based on force propagation through an elastic material reproduces the main features of bridge maintenance and tension distribution. Our findings suggest that multicellular bridges maintain tissue integrity during wound healing when cell-substrate interactions are weak and may prove helpful in the design of artificial scaffolds for skin regeneration.

  15. Pancreatic Tumor Cell Secreted CCN1/Cyr61 Promotes Endothelial cell migration and Aberrant Neovascularization

    PubMed Central

    Maity, Gargi; Mehta, Smita; Haque, Inamul; Dhar, Kakali; Sarkar, Sandipto; Banerjee, Sushanta K.; Banerjee, Snigdha

    2014-01-01

    The complex signaling networks between cancer cells and adjacent endothelial cells make it challenging to unravel how cancer cells send extracellular messages to promote aberrant vascularization or tumor angiogenesis. Here, in vitro and in vivo models show that pancreatic cancer cell generated unique microenvironments can underlie endothelial cell migration and tumor angiogenesis. Mechanistically, we find that pancreatic cancer cell secreted CCN1/Cyr61 matricellular protein rewires the microenvironment to promote endothelial cell migration and tumor angiogenesis. This event can be overcome by Sonic Hedgehog (SHh) antibody treatment. Collectively, these studies identify a novel CCN1 signaling program in pancreatic cancer cells which activates SHh through autocrine-paracrine circuits to promote endothelial cell migration and tumor angiogenesis and suggests that CCN1 signaling of pancreatic cancer cells is vital for the regulation of tumor angiogenesis. Thus CCN1 signaling could be an ideal target for tumor vascular disruption in pancreatic cancer. PMID:24833309

  16. Directional Collective Cell Migration Emerges as a Property of Cell Interactions

    PubMed Central

    Woods, Mae L.; Carmona-Fontaine, Carlos; Barnes, Chris P.; Couzin, Iain D.; Mayor, Roberto; Page, Karen M.

    2014-01-01

    Collective cell migration is a fundamental process, occurring during embryogenesis and cancer metastasis. Neural crest cells exhibit such coordinated migration, where aberrant motion can lead to fatality or dysfunction of the embryo. Migration involves at least two complementary mechanisms: contact inhibition of locomotion (a repulsive interaction corresponding to a directional change of migration upon contact with a reciprocating cell), and co-attraction (a mutual chemoattraction mechanism). Here, we develop and employ a parameterized discrete element model of neural crest cells, to investigate how these mechanisms contribute to long-range directional migration during development. Motion is characterized using a coherence parameter and the time taken to reach, collectively, a target location. The simulated cell group is shown to switch from a diffusive to a persistent state as the response-rate to co-attraction is increased. Furthermore, the model predicts that when co-attraction is inhibited, neural crest cells can migrate into restrictive regions. Indeed, inhibition of co-attraction in vivo and in vitro leads to cell invasion into restrictive areas, confirming the prediction of the model. This suggests that the interplay between the complementary mechanisms may contribute to guidance of the neural crest. We conclude that directional migration is a system property and does not require action of external chemoattractants. PMID:25181349

  17. The Role of Crk Adaptor Proteins in T-Cell Adhesion and Migration

    PubMed Central

    Braiman, Alex; Isakov, Noah

    2015-01-01

    Crk adaptor proteins are key players in signal transduction from a variety of cell surface receptors. They are involved in early steps of lymphocyte activation through their SH2-mediated transient interaction with signal transducing effector molecules, such as Cbl, ZAP-70, CasL, and STAT5. In addition, they constitutively associate, via their SH3 domain, with effector molecules, such as C3G, that mediate cell adhesion and regulate lymphocyte extravasation and recruitment to sites of inflammation. Recent studies demonstrated that the conformation and function of CrkII is subjected to a regulation by immunophilins, which also affect CrkII-dependent T-cell adhesion to fibronectin and migration toward chemokines. This article addresses mechanisms that regulate CrkII conformation and function, in general, and emphasizes the role of Crk proteins in receptor-coupled signaling pathways that control T-lymphocyte adhesion and migration to inflammatory sites. PMID:26500649

  18. Novel interactions between erythroblast macrophage protein and cell migration.

    PubMed

    Javan, Gulnaz T; Can, Ismail; Yeboah, Fred; Lee, Youngil; Soni, Shivani

    2016-09-01

    Erythroblast macrophage protein is a novel protein known to mediate attachment of erythroid cells to macrophages to form erythroblastic islands in bone marrow during erythropoiesis. Emp-null macrophages are small with round morphologies, and lack cytoplasmic projections which imply immature structure. The role of Emp in macrophage development and function is not fully elucidated. Macrophages perform varied functions (e.g. homeostasis, erythropoiesis), and are implicated in numerous pathophysiological conditions such as cellular malignancy. The objective of the current study is to investigate the interaction of Emp with cytoskeletal- and cell migration-associated proteins involved in macrophage functions. A short hairpin RNA lentiviral system was use to down-regulate the expression of Emp in macrophage cells. A cell migration assay revealed that the relocation of macrophages was significantly inhibited when Emp expression was decreased. To further analyze changes in gene expression related to cell motility, PCR array was performed by down-regulating Emp expression. The results indicated that expression of mitogen-activated protein kinase 1 and thymoma viral proto-oncogene 1 were significantly higher when Emp was down-regulated. The results implicate Emp in abnormal cell motility, thus, warrants to assess its role in cancer where tumor cell motility is required for invasion and metastasis. PMID:27519940

  19. Novel interactions between erythroblast macrophage protein and cell migration.

    PubMed

    Javan, Gulnaz T; Can, Ismail; Yeboah, Fred; Lee, Youngil; Soni, Shivani

    2016-09-01

    Erythroblast macrophage protein is a novel protein known to mediate attachment of erythroid cells to macrophages to form erythroblastic islands in bone marrow during erythropoiesis. Emp-null macrophages are small with round morphologies, and lack cytoplasmic projections which imply immature structure. The role of Emp in macrophage development and function is not fully elucidated. Macrophages perform varied functions (e.g. homeostasis, erythropoiesis), and are implicated in numerous pathophysiological conditions such as cellular malignancy. The objective of the current study is to investigate the interaction of Emp with cytoskeletal- and cell migration-associated proteins involved in macrophage functions. A short hairpin RNA lentiviral system was use to down-regulate the expression of Emp in macrophage cells. A cell migration assay revealed that the relocation of macrophages was significantly inhibited when Emp expression was decreased. To further analyze changes in gene expression related to cell motility, PCR array was performed by down-regulating Emp expression. The results indicated that expression of mitogen-activated protein kinase 1 and thymoma viral proto-oncogene 1 were significantly higher when Emp was down-regulated. The results implicate Emp in abnormal cell motility, thus, warrants to assess its role in cancer where tumor cell motility is required for invasion and metastasis.

  20. Lysophosphatidic acid induces cell migration through the selective activation of Akt1

    PubMed Central

    Kim, Eun Kyoung; Yun, Sung Ji; Do, Kee Hun; Kim, Min Sung; Cho, Mong; Suh, Dong-Soo; Kim, Chi Dae; Kim, Jae Ho; Birnbaum, Morris J.

    2008-01-01

    Akt plays pivotal roles in many physiological responses including growth, proliferation, survival, metabolism, and migration. In the current studies, we have evaluated the isoform-specific role of akt in lysophosphatidic acid (LPA)-induced cell migration. Ascites from ovarian cancer patients (AOCP) induced mouse embryo fibroblast (MEF) cell migration in a dose-dependent manner. On the other hand, ascites from liver cirrhosis patients (ALCP) did not induce MEF cell migration. AOCP-induced MEF cell migration was completely blocked by pre-treatment of cells with LPA receptor antagonist, Ki16425. Both LPA- and AOCP-induced MEF cell migration was completely attenuated by PI3K inhibitor, LY294002. Furthermore, cells lacking Akt1 displayed defect in LPA-induced cell migration. Re-expression of Akt1 in DKO (Akt1-/-Akt2-/-) cells restored LPA-induced cell migration, whereas re-expression of Akt2 in DKO cells could not restore the LPA-induced cell migration. Finally, Akt1 was selectively phosphorylated by LPA and AOCP stimulation. These results suggest that LPA is a major factor responsible for AOCP-induced cell migration and signaling specificity of Akt1 may dictate LPA-induced cell migration. PMID:18779657

  1. Serotonin induces pulmonary artery smooth muscle cell migration

    PubMed Central

    Day, Regina M.; Agyeman, Abena S.; Segel, Michael J.; Chévere, Rubén D.; Angelosanto, Jill M.; Suzuki, Yuichiro J.; Fanburg, Barry L.

    2007-01-01

    The chronic phase of pulmonary arterial hypertension (PAH) is associated with vascular remodeling, especially thickening of the smooth muscle layer of large pulmonary arteries and muscularization of small pulmonary vessels, which normally have no associated smooth muscle. Serotonin (5-hydroxytryptamine, 5-HT) has been shown to induce proliferation and hypertrophy of pulmonary artery smooth muscle cells (PASMC), and may be important for in vivo pulmonary vascular remodeling. Here, we show that 5-HT stimulates migration of pulmonary artery PASMC. Treatment with 5-HT for 16 h increased migration of PASMC up to four-fold as monitored in a modified Boyden chamber assay. Increased migratory responses were associated with cellular morphological changes and reorganization of the actin cytoskeleton. 5-HT-induced alterations in morphology were previously shown in our laboratory to require cAMP [Lee SL, Fanburg BL. Serotonin produces a configurational change of cultured smooth muscle cells that is associated with elevation of intracellular cAMP. J Cell Phys 1992;150(2):396–405], and the 5-HT4 receptor was pharmacologically determined to be the primary activator of cAMP in bovine PASMC [Becker BN, Gettys TW, Middleton JP, Olsen CL, Albers FJ, Lee SL, et al. 8-Hydroxy-2-(di-n-propylamino)tetralin-responsive 5-hydroxytryptamine4-like receptor expressed in bovine pulmonary artery smooth muscle cells. Mol Pharmacol 1992;42(5):817–25]. We examined the role of the 5-HT4 receptor and cAMP in 5-HT-induced bovine PASMC migration. PASMC express 5-HT4 receptor mRNA, and a 5-HT4 receptor antagonist and a cAMP antagonist completely blocked 5-HT-induced cellular migration. Consistent with our previous report that a cAMP-dependent Cl− channel is required for 5-HT-induced morphological changes in PASMC, phenylanthranilic acid, a Cl− channel blocker, inhibited actin cytoskeletal reorganization and migration produced by 5-HT. We conclude that 5-HT stimulates PASMC migration and

  2. Retinoic acid inhibits migration of cranial neural crest cells in the cultured mouse embryo.

    PubMed

    Pratt, R M; Goulding, E H; Abbott, B D

    1987-01-01

    Clinical observations have demonstrated that isotretinoin (13-cis-retinoic acid; cis-RA) is a human teratogen causing primarily heart and craniofacial malformations. Isotretinoin exposure to the early postimplantation mouse embryo in culture results in specific defects in craniofacial development that may be due to an interference in the early migration of cranial neural crest (CNC) cells [Goulding and Pratt, 1986]. The present study was designed to test this hypothesis by examining the migration of these cells in whole embryo culture. Day 8 CD-1 mouse embryos were cultured for 6-48 hr in the presence or absence of cis-RA at 2 X 10(-6) to 2 X 10(-5) M. Embryos either were fixed for light microscopy using Nichols' method for localization of CNC cells or were processed for scanning and transmission electron microscopy. At the light microscopic level, CNC cells in the mid-brain region of control embryos had migrated to the region of the first and second visceral arches after 6 hr in culture. Cis-RA interfered with this migration; CNC cells in treated embryos either did not leave the neuroepithelium (NE) or were aggregated near the NE. Autoradiographic studies indicated that cis-RA did not affect the overall viability or DNA synthesis of the CNC cells. However, at the TEM level, there was a dramatic increase in the number of cellular blebs in the CNC cells. Our results demonstrate a direct effect of 13-cis-RA on the CNC cells and suggest that this effect is due to alterations in the cell surface.

  3. Effects of microtubule-associated protein tau expression on neural stem cell migration after spinal cord injury

    PubMed Central

    Qi, Zhi-ping; Wang, Guo-xiang; Xia, Peng; Hou, Ting-ting; Zhou, Hong-li; Wang, Tie-jun; Yang, Xiao-yu

    2016-01-01

    Our preliminary proteomics analysis suggested that expression of microtubule-associated protein tau is elevated in the spinal cord after injury. Therefore, the first aim of the present study was to examine tau expression in the injured spinal cord. The second aim was to determine whether tau can regulate neural stem cell migration, a critical factor in the successful treatment of spinal cord injury. We established rat models of spinal cord injury and injected them with mouse hippocampal neural stem cells through the tail vein. We used immunohistochemistry to show that the expression of tau protein and the number of migrated neural stem cells were markedly increased in the injured spinal cord. Furthermore, using a Transwell assay, we showed that neural stem cell migration was not affected by an elevated tau concentration in the outer chamber, but it was decreased by changes in intracellular tau phosphorylation state. These results demonstrate that neural stem cells have targeted migration capability at the site of injury, and that although tau is not a chemokine for targeted migration of neural stem cells, intracellular tau phosphorylation/dephosphorylation can inhibit cell migration. PMID:27073389

  4. NFAT transcription factors regulate survival, proliferation, migration, and differentiation of neural precursor cells.

    PubMed

    Serrano-Pérez, María C; Fernández, Miriam; Neria, Fernando; Berjón-Otero, Mónica; Doncel-Pérez, Ernesto; Cano, Eva; Tranque, Pedro

    2015-06-01

    The study of factors that regulate the survival, proliferation, and differentiation of neural precursor cells (NPCs) is essential to understand neural development as well as brain regeneration. The Nuclear Factor of Activated T Cells (NFAT) is a family of transcription factors that can affect these processes besides playing key roles during development, such as stimulating axonal growth in neurons, maturation of immune system cells, heart valve formation, and differentiation of skeletal muscle and bone. Interestingly, NFAT signaling can also promote cell differentiation in adults, participating in tissue regeneration. The goal of the present study is to evaluate the expression of NFAT isoforms in NPCs, and to investigate its possible role in NPC survival, proliferation, migration, and differentiation. Our findings indicate that NFAT proteins are active not only in neurogenic brain regions such as hippocampus and subventricular zone (SVZ), but also in cultured NPCs. The inhibition of NFAT activation with the peptide VIVIT reduced neurosphere size and cell density in NPC cultures by decreasing proliferation and increasing cell death. VIVIT also decreased NPC migration and differentiation of astrocytes and neurons from NPCs. In addition, we identified NFATc3 as a predominant NFAT isoform in NPC cultures, finding that a constitutively-active form of NFATc3 expressed by adenoviral infection reduces NPC proliferation, stimulates migration, and is a potent inducer of NPC differentiation into astrocytes and neurons. In summary, our work uncovers active roles for NFAT signaling in NPC survival, proliferation and differentiation, and highlights its therapeutic potential for tissue regeneration.

  5. Naringenin is a novel inhibitor of Dictyostelium cell proliferation and cell migration

    SciTech Connect

    Russ, Misty; Martinez, Raquel; Ali, Hind; Steimle, Paul A. . E-mail: p_steiml@uncg.edu

    2006-06-23

    Naringenin is a flavanone compound that alters critical cellular processes such as cell multiplication, glucose uptake, and mitochondrial activity. In this study, we used the social amoeba, Dictyostelium discoideum, as a model system for examining the cellular processes and signaling pathways affected by naringenin. We found that naringenin inhibited Dictyostelium cell division in a dose-dependent manner (IC{sub 5} {approx} 20 {mu}M). Assays of Dictyostelium chemotaxis and multicellular development revealed that naringenin possesses a previously unrecognized ability to suppress amoeboid cell motility. We also found that naringenin, which is known to inhibit phosphatidylinositol 3-kinase activity, had no apparent effect on phosphatidylinositol 3,4,5-trisphosphate synthesis in live Dictyostelium cells; suggesting that this compound suppresses cell growth and migration via alternative signaling pathways. In another context, the discoveries described here highlight the value of using the Dictyostelium model system for identifying and characterizing the mechanisms by which naringenin, and related compounds, exert their effects on eukaryotic cells.

  6. Naringenin is a novel inhibitor of Dictyostelium cell proliferation and cell migration.

    PubMed

    Misty, Russ; Martinez, Raquel; Ali, Hind; Steimle, Paul A

    2006-06-23

    Naringenin is a flavanone compound that alters critical cellular processes such as cell multiplication, glucose uptake, and mitochondrial activity. In this study, we used the social amoeba, Dictyostelium discoideum, as a model system for examining the cellular processes and signaling pathways affected by naringenin. We found that naringenin inhibited Dictyostelium cell division in a dose-dependent manner (IC(50) approximately 20 microM). Assays of Dictyostelium chemotaxis and multicellular development revealed that naringenin possesses a previously unrecognized ability to suppress amoeboid cell motility. We also found that naringenin, which is known to inhibit phosphatidylinositol 3-kinase activity, had no apparent effect on phosphatidylinositol 3,4,5-trisphosphate synthesis in live Dictyostelium cells; suggesting that this compound suppresses cell growth and migration via alternative signaling pathways. In another context, the discoveries described here highlight the value of using the Dictyostelium model system for identifying and characterizing the mechanisms by which naringenin, and related compounds, exert their effects on eukaryotic cells. PMID:16682000

  7. ADAM17 is critical for multipolar exit and radial migration of neuronal intermediate progenitor cells in mice cerebral cortex.

    PubMed

    Li, Qingyu; Zhang, Zhengyu; Li, Zengmin; Zhou, Mei; Liu, Bin; Pan, Le; Ma, Zhixing; Zheng, Yufang

    2013-01-01

    The radial migration of neuronal progenitor cells is critical for the development of cerebral cortex layers. They go through a critical step transforming from multipolar to bipolar before outward migration. A Disintegrin and Metalloprotease 17 (ADAM17) is a transmembrane protease which can process many substrates involved in cell-cell interaction, including Notch, ligands of EGFR, and some cell adhesion molecules. In this study, we used in utero electroporation to knock down or overexpress ADAM17 at embryonic day 14.5 (E14.5) in neuronal progenitor cells to examine the role of ADAM17 in cortical embryonic neurogenesis. Our results showed that the radial migration of ADAM17-knocked down cells were normal till E16.5 and reached the intermediate zone (IZ). Then most transfected cells stopped migration and stayed at the IZ to inner cortical plate (CP) layer at E18.5, and there was higher percentage of multipolar cells at IZ layer in the ADAM17-knocked down group compared to the cells in control group. Marker staining revealed that those ADAM17-knocked down cells differentiated normally from neural stem cells (NSCs) to neuronal intermediate progenitor cells (nIPCs) but did not differentiate into mature neurons. The migration and multipolar exit defects caused by ADAM17 knockdown could be partially rescued by over-expressing an shRNA resistant ADAM17, while overexpressing ADAM17 alone did not affect the radial migration. Taken together, our results showed for the first time that, ADAM17 is critical in regulating the multipolar-stage exit and radial migration of the nIPCs during telencephalon cortex development in mice. PMID:23755270

  8. ADAM17 is critical for multipolar exit and radial migration of neuronal intermediate progenitor cells in mice cerebral cortex.

    PubMed

    Li, Qingyu; Zhang, Zhengyu; Li, Zengmin; Zhou, Mei; Liu, Bin; Pan, Le; Ma, Zhixing; Zheng, Yufang

    2013-01-01

    The radial migration of neuronal progenitor cells is critical for the development of cerebral cortex layers. They go through a critical step transforming from multipolar to bipolar before outward migration. A Disintegrin and Metalloprotease 17 (ADAM17) is a transmembrane protease which can process many substrates involved in cell-cell interaction, including Notch, ligands of EGFR, and some cell adhesion molecules. In this study, we used in utero electroporation to knock down or overexpress ADAM17 at embryonic day 14.5 (E14.5) in neuronal progenitor cells to examine the role of ADAM17 in cortical embryonic neurogenesis. Our results showed that the radial migration of ADAM17-knocked down cells were normal till E16.5 and reached the intermediate zone (IZ). Then most transfected cells stopped migration and stayed at the IZ to inner cortical plate (CP) layer at E18.5, and there was higher percentage of multipolar cells at IZ layer in the ADAM17-knocked down group compared to the cells in control group. Marker staining revealed that those ADAM17-knocked down cells differentiated normally from neural stem cells (NSCs) to neuronal intermediate progenitor cells (nIPCs) but did not differentiate into mature neurons. The migration and multipolar exit defects caused by ADAM17 knockdown could be partially rescued by over-expressing an shRNA resistant ADAM17, while overexpressing ADAM17 alone did not affect the radial migration. Taken together, our results showed for the first time that, ADAM17 is critical in regulating the multipolar-stage exit and radial migration of the nIPCs during telencephalon cortex development in mice.

  9. Cu Migration in Polycrystalline CdTe Solar Cells

    SciTech Connect

    Guo, Da; Akis, Richard; Brinkman, Daniel; Sankin, Igor; Fang, Tian; Vasileska, Dragica; Ringhofer, Christian

    2014-03-12

    An impurity reaction-diffusion model is applied to Cu defects and related intrinsic defects in polycrystalline CdTe for a better understanding of Cu’s role in the cell level reliability of CdTe PV devices. The simulation yields transient Cu distributions in polycrystalline CdTe during solar cell processing and stressing. Preliminary results for Cu migration using available diffusivity and solubility data show that Cu accumulates near the back contact, a phenomena that is commonly observed in devices after back-contact processing or stress conditions.

  10. Integrating focal adhesion dynamics, cytoskeleton remodeling, and actin motor activity for predicting cell migration on 3D curved surfaces of the extracellular matrix.

    PubMed

    Kim, Min-Cheol; Kim, Choong; Wood, Levi; Neal, Devin; Kamm, Roger D; Asada, H Harry

    2012-11-01

    An integrative cell migration model incorporating focal adhesion (FA) dynamics, cytoskeleton and nucleus remodeling and actin motor activity is developed for predicting cell migration behaviors on 3-dimensional curved surfaces, such as cylindrical lumens in the 3-D extracellular matrix (ECM). The work is motivated by 3-D microfluidic migration experiments suggesting that the migration speed and direction may vary depending on the cross sectional shape of the lumen along which the cell migrates. In this paper, the mechanical structure of the cell is modeled as double elastic membranes of cell and nucleus. The two elastic membranes are connected by stress fibers, which are extended from focal adhesions on the cell surface to the nuclear membrane. The cell deforms and gains traction as transmembrane integrins distributed over the outer cell membrane bind to ligands on the ECM, form focal adhesions, and activate stress fibers. Probabilities at which integrin ligand-receptor bonds are formed as well as ruptures are affected by the surface geometry, resulting in diverse migration behaviors that depend on the curvature of the surface. Monte Carlo simulations of the integrative model reveal that (a) the cell migration speed is dependent on the cross sectional area of the lumen with a maximum speed at a particular diameter or width, (b) as the lumen diameter increases, the cell tends to spread and migrate around the circumference of the lumen, while it moves in the longitudinal direction as the lumen diameter narrows, (c) once the cell moves in one direction, it tends to stay migrating in the same direction despite the stochastic nature of migration. The relationship between the cell migration speed and the lumen width agrees with microfluidic experimental data for cancer cell migration.

  11. Functional screening with a live cell imaging-based random cell migration assay.

    PubMed

    van Roosmalen, Wies; Le Dévédec, Sylvia E; Zovko, Sandra; de Bont, Hans; van de Water, Bob

    2011-01-01

    Cell migration, essential in cancer progression, is a complex process comprising a number of spatiotemporally regulated and well-coordinated mechanisms. In order to study (random) cell migration in the context of responses to various external cues (such as growth factors) or intrinsic cell signaling, a number of different tools and approaches have been developed. In order to unravel the key pathways and players involved in the regulation of (cancer) cell migration, a systematical mapping of the players/pathways is required. For this purpose, we developed a cell migration assay based on automatic high-throughput microscopy screen. This approach allows for screening of hundreds of genes, e.g., those encoding various kinases and phosphatases but can also be used for screening of drugs libraries. Moreover, we have developed an automatic analysis pipeline comprising of (a) automatic data acquisition (movie) and (b) automatic analysis of the acquired movies of the migrating cells. Here, we describe various facets of this approach. Since cell migration is essential in progression of cancer metastasis, we describe two examples of experiments performed on highly motile (metastatic) cancer cells.

  12. Cell traction in collective cell migration and morphogenesis: The chase and run mechanism

    PubMed Central

    Szabó, András; Mayor, Roberto

    2015-01-01

    Directional collective cell migration plays an important role in development, physiology, and disease. An increasing number of studies revealed key aspects of how cells coordinate their movement through distances surpassing several cell diameters. While physical modeling and measurements of forces during collective cell movements helped to reveal key mechanisms, most of these studies focus on tightly connected epithelial cultures. Less is known about collective migration of mesenchymal cells. A typical example of such behavior is the migration of the neural crest cells, which migrate large distances as a group. A recent study revealed that this persistent migration is aided by the interaction between the neural crest and the neighboring placode cells, whereby neural crest chase the placodes via chemotaxis, but upon contact both populations undergo contact inhibition of locomotion and a rapid reorganization of cellular traction. The resulting asymmetric traction field of the placodes forces them to run away from the chasers. We argue that this chase and run interaction may not be specific only to the neural crest system, but could serve as the underlying mechanism for several morphogenetic processes involving collective cell migration. PMID:26267782

  13. 17β-Estradiol treatment inhibits breast cell proliferation, migration and invasion by decreasing MALAT-1 RNA level

    SciTech Connect

    Zhao, Ziyi; Chen, Changjin; Liu, Yu; Wu, Chuanfang

    2014-03-07

    Highlights: • E2 affects not only estrogen-receptor α positive breast cells but also negative ones. • 100 nM E2 treatment affects breast cells proliferation, migration. • 100 nM E2 treatment functions in an estrogen-receptor α-independent way. • E2 treatment decreases MALAT-1 RNA level by post-transcriptional regulation. - Abstract: Breast cancer cells, which express estrogen receptor α (ERα), respond to estrogen in a concentration dependent fashion, resulting in proliferation or apoptosis. But breast cancer cells without ERα show no effect on low concentration of estrogen treatment. Proliferation, migration and invasion of MCF10a, MCF7 and MB231 cells treated with low (1 nM) or high (100 nM) dose of 17β-Estradiol (E2) was performed. We identified the effects of E2 on these breast cell lines, and looked for the difference in the presence and absence of ERα. Specifically, we looked for the changes of long non-coding RNA metastasis associated lung adenocarcinoma transcript 1 (MALAT-1), which is found extensively and highly expressed in several kinds of tumor cells, including breast carcinoma. It was observed that proliferation, migration and invasion of breast cells were greatly affected by high concentration E2 treatment and were not affected by low concentration E2 treatment in an ERα independent way. We found that the high concentration E2 treatment largely decreased MALAT-1 RNA level. Interestingly, MALAT-1 decreasing by knocking down showed similar effects on proliferation, migration and invasion. E2 treatment affects breast tumor or non-tumor cells proliferation, migration and invasion in an ERα -independent, but a dose-dependent way by decreasing the MALAT-1 RNA level.

  14. Activated protein C promotes breast cancer cell migration through interactions with EPCR and PAR-1

    SciTech Connect

    Beaulieu, Lea M.; Church, Frank C. . E-mail: fchurch@email.unc.edu

    2007-02-15

    Activated protein C (APC) is a serine protease that regulates thrombin (IIa) production through inactivation of blood coagulation factors Va and VIIIa. APC also has non-hemostatic functions related to inflammation, proliferation, and apoptosis through various mechanisms. Using two breast cancer cell lines, MDA-MB-231 and MDA-MB-435, we investigated the role of APC in cell chemotaxis and invasion. Treatment of cells with increasing APC concentrations (1-50 {mu}g/ml) increased invasion and chemotaxis in a concentration-dependent manner. Only the active form of APC increased invasion and chemotaxis of the MDA-MB-231 cells when compared to 3 inactive APC derivatives. Using a modified 'checkerboard' analysis, APC was shown to only affect migration when plated with the cells; therefore, APC is not a chemoattractant. Blocking antibodies to endothelial protein C receptor (EPCR) and protease-activated receptor-1 (PAR-1) attenuated the effects of APC on chemotaxis in the MDA-MB-231 cells. Finally, treatment of the MDA-MB-231 cells with the proliferation inhibitor, Na butyrate, showed that APC did not increase migration by increasing cell number. Therefore, APC increases invasion and chemotaxis of cells by binding to the cell surface and activating specific signaling pathways through EPCR and PAR-1.

  15. Genome-wide analysis of Musashi-2 targets reveals novel functions in governing epithelial cell migration

    PubMed Central

    Bennett, Christopher G.; Riemondy, Kent; Chapnick, Douglas A.; Bunker, Eric; Liu, Xuedong; Kuersten, Scott; Yi, Rui

    2016-01-01

    The Musashi-2 (Msi2) RNA-binding protein maintains stem cell self-renewal and promotes oncogenesis by enhancing cell proliferation in hematopoietic and gastrointestinal tissues. However, it is unclear how Msi2 recognizes and regulates mRNA targets in vivo and whether Msi2 primarily controls cell growth in all cell types. Here we identified Msi2 targets with HITS-CLIP and revealed that Msi2 primarily recognizes mRNA 3′UTRs at sites enriched in multiple copies of UAG motifs in epithelial progenitor cells. RNA-seq and ribosome profiling demonstrated that Msi2 promotes targeted mRNA decay without affecting translation efficiency. Unexpectedly, the most prominent Msi2 targets identified are key regulators that govern cell motility with a high enrichment in focal adhesion and extracellular matrix-receptor interaction, in addition to regulators of cell growth and survival. Loss of Msi2 stimulates epithelial cell migration, increases the number of focal adhesions and also compromises cell growth. These findings provide new insights into the molecular mechanisms of Msi2's recognition and repression of targets and uncover a key function of Msi2 in restricting epithelial cell migration. PMID:27034466

  16. Genome-wide analysis of Musashi-2 targets reveals novel functions in governing epithelial cell migration.

    PubMed

    Bennett, Christopher G; Riemondy, Kent; Chapnick, Douglas A; Bunker, Eric; Liu, Xuedong; Kuersten, Scott; Yi, Rui

    2016-05-01

    The Musashi-2 (Msi2) RNA-binding protein maintains stem cell self-renewal and promotes oncogenesis by enhancing cell proliferation in hematopoietic and gastrointestinal tissues. However, it is unclear how Msi2 recognizes and regulates mRNA targets in vivo and whether Msi2 primarily controls cell growth in all cell types. Here we identified Msi2 targets with HITS-CLIP and revealed that Msi2 primarily recognizes mRNA 3'UTRs at sites enriched in multiple copies of UAG motifs in epithelial progenitor cells. RNA-seq and ribosome profiling demonstrated that Msi2 promotes targeted mRNA decay without affecting translation efficiency. Unexpectedly, the most prominent Msi2 targets identified are key regulators that govern cell motility with a high enrichment in focal adhesion and extracellular matrix-receptor interaction, in addition to regulators of cell growth and survival. Loss of Msi2 stimulates epithelial cell migration, increases the number of focal adhesions and also compromises cell growth. These findings provide new insights into the molecular mechanisms of Msi2's recognition and repression of targets and uncover a key function of Msi2 in restricting epithelial cell migration. PMID:27034466

  17. Mechanobiology of cell migration in the context of dynamic two-way cell-matrix interactions.

    PubMed

    Kurniawan, Nicholas A; Chaudhuri, Parthiv Kant; Lim, Chwee Teck

    2016-05-24

    Migration of cells is integral in various physiological processes in all facets of life. These range from embryonic development, morphogenesis, and wound healing, to disease pathology such as cancer metastasis. While cell migratory behavior has been traditionally studied using simple assays on culture dishes, in recent years it has been increasingly realized that the physical, mechanical, and chemical aspects of the matrix are key determinants of the migration mechanism. In this paper, we will describe the mechanobiological changes that accompany the dynamic cell-matrix interactions during cell migration. Furthermore, we will review what is to date known about how these changes feed back to the dynamics and biomechanical properties of the cell and the matrix. Elucidating the role of these intimate cell-matrix interactions will provide not only a better multi-scale understanding of cell motility in its physiological context, but also a more holistic perspective for designing approaches to regulate cell behavior.

  18. Human Mesenchymal Stem Cell Morphology and Migration on Microtextured Titanium

    PubMed Central

    Banik, Brittany L.; Riley, Thomas R.; Platt, Christina J.; Brown, Justin L.

    2016-01-01

    The implant used in spinal fusion procedures is an essential component to achieving successful arthrodesis. At the cellular level, the implant impacts healing and fusion through a series of steps: first, mesenchymal stem cells (MSCs) need to adhere and proliferate to cover the implant; second, the MSCs must differentiate into osteoblasts; third, the osteoid matrix produced by the osteoblasts needs to generate new bone tissue, thoroughly integrating the implant with the vertebrate above and below. Previous research has demonstrated that microtextured titanium is advantageous over smooth titanium and PEEK implants for both promoting osteogenic differentiation and integrating with host bone tissue; however, no investigation to date has examined the early morphology and migration of MSCs on these surfaces. This study details cell spreading and morphology changes over 24 h, rate and directionality of migration 6–18 h post-seeding, differentiation markers at 10 days, and the long-term morphology of MSCs at 7 days, on microtextured, acid-etched titanium (endoskeleton), smooth titanium, and smooth PEEK surfaces. The results demonstrate that in all metrics, the two titanium surfaces outperformed the PEEK surface. Furthermore, the rough acid-etched titanium surface presented the most favorable overall results, demonstrating the random migration needed to efficiently cover a surface in addition to morphologies consistent with osteoblasts and preosteoblasts. PMID:27243001

  19. Exploring the control circuit of cell migration by mathematical modeling.

    PubMed

    Satulovsky, Javier; Lui, Roger; Wang, Yu-li

    2008-05-01

    We have developed a top-down, rule-based mathematical model to explore the basic principles that coordinate mechanochemical events during animal cell migration, particularly the local-stimulation-global-inhibition model suggested originally for chemotaxis. Cells were modeled as a shape machine that protrudes or retracts in response to a combination of local protrusion and global retraction signals. Using an optimization algorithm to identify parameters that generate specific shapes and migration patterns, we show that the mechanism of local stimulation global inhibition can readily account for the behavior of Dictyostelium under a large collection of conditions. Within this collection, some parameters showed strong correlation, indicating that a normal phenotype may be maintained by complementation among functional modules. In addition, comparison of parameters for control and nocodazole-treated Dictyostelium identified the most prominent effect of microtubules as regulating the rates of retraction and protrusion signal decay, and the extent of global inhibition. Other changes in parameters can lead to profound transformations from amoeboid cells into cells mimicking keratocytes, neurons, or fibroblasts. Thus, a simple circuit of local stimulation-global inhibition can account for a wide range of cell behaviors. A similar top-down approach may be applied to other complex problems and combined with molecular manipulations to define specific protein functions.

  20. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating.

    PubMed

    Munholland, Jonah L; Mumford, Kevin G; Kueper, Bernard H

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water.

  1. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating

    NASA Astrophysics Data System (ADS)

    Munholland, Jonah L.; Mumford, Kevin G.; Kueper, Bernard H.

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water.

  2. Factors affecting gas migration and contaminant redistribution in heterogeneous porous media subject to electrical resistance heating.

    PubMed

    Munholland, Jonah L; Mumford, Kevin G; Kueper, Bernard H

    2016-01-01

    A series of intermediate-scale laboratory experiments were completed in a two-dimensional flow cell to investigate gas production and migration during the application of electrical resistance heating (ERH) for the removal of dense non-aqueous phase liquids (DNAPLs). Experiments consisted of heating water in homogeneous silica sand and heating 270 mL of trichloroethene (TCE) and chloroform (CF) DNAPL pools in heterogeneous silica sands, both under flowing groundwater conditions. Spatial and temporal distributions of temperature were measured using thermocouples and observations of gas production and migration were collected using front-face image capture throughout the experiments. Post-treatment soil samples were collected and analyzed to assess DNAPL removal. Results of experiments performed in homogeneous sand subject to different groundwater flow rates showed that high groundwater velocities can limit subsurface heating rates. In the DNAPL pool experiments, temperatures increased to achieve DNAPL-water co-boiling, creating estimated gas volumes of 131 and 114 L that originated from the TCE and CF pools, respectively. Produced gas migrated vertically, entered a coarse sand lens and subsequently migrated laterally beneath an overlying capillary barrier to outside the heated treatment zone where 31-56% of the original DNAPL condensed back into a DNAPL phase. These findings demonstrate that layered heterogeneity can potentially facilitate the transport of contaminants outside the treatment zone by mobilization and condensation of gas phases during ERH applications. This underscores the need for vapor phase recovery and/or control mechanisms below the water table during application of ERH in heterogeneous porous media during the co-boiling stage, which occurs prior to reaching the boiling point of water. PMID:26638038

  3. Magnolol inhibits migration of vascular smooth muscle cells via cytoskeletal remodeling pathway to attenuate neointima formation

    SciTech Connect

    Karki, Rajendra; Kim, Seong-Bin; Kim, Dong-Wook

    2013-12-10

    Background: Increased proliferation and migration of vascular smooth muscle cells (VSMCs) contribute importantly to the formation of both atherosclerotic and restenotic lesions. The objective of this study was to investigate the effect of magnolol on VSMC migration. Methods: The proteolytic activity of matrix metalloproteinases (MMPs) in tumor necrosis factor alpha (TNF-α) stimulated VSMCs was performed by gelatin zymography. VSMC migration was assessed by wound healing and Boyden chamber methods. Collagen induced VSMC adhesion was determined by spectrofluorimeter and stress fibers formation was evaluated by fluorescence microscope. The expression of signaling molecules involved in stress fibers formation was determined by western blot. The phosphorylation of myosin light chain (MLC20) was determined by urea-glycerol polyacrylamide gel electrophoresis. Immunohistochemistry was performed to determine the expression of β1-integrin and collagen type I in the injured carotid arteries of rats on day 35 after vascular injury. Results: VSMC migration was strongly inhibited by magnolol without affecting MMPs expression. Also, magnolol inhibited β1-integrin expression, FAK phosphorylation and RhoA and Cdc42 activation to inhibit the collagen induced stress fibers formation. Moreover, magnolol inhibited the phosphorylation of MLC20. Our in vivo results showed that magnolol inhibited β1-integrin expression, collagen type I deposition and FAK phosphorylation in injured carotid arteries without affecting MMP-2 activity. Conclusions: Magnolol inhibited VSMC migration via inhibition of cytoskeletal remodeling pathway to attenuate neointima formation. General significance: This study provides a rationale for further evaluation of magnolol for the management of atherosclerosis and restenosis. - Highlights: • Magnolol strongly inhibited migration of VSMCs. • Magnolol inhibited stress fibers formation. • MLC20 phosphorylation was also inhibited by magnolol. • Anti

  4. TGF-βI Regulates Cell Migration through Pluripotent Transcription Factor OCT4 in Endometriosis

    PubMed Central

    Au, Heng-Kien; Chang, Jui-Hung; Wu, Yu-Chih; Kuo, Yung-Che; Chen, Yu-Hsi; Lee, Wei-Chin; Chang, Te-Sheng; Lan, Pei-Chi; Kuo, Hung-Chih; Lee, Kha-Liang; Lee, Mei-Tsu; Tzeng, Chii-Ruey; Huang, Yen-Hua

    2015-01-01

    Transforming growth factor (TGF-β)/TGF-β receptor signal is known to promote cell migration. Up-regulation of TGF-β in serum/peritoneal fluid and increased levels of pluripotent transcription factor OCT4 in endometriotic tissues are frequently observed in patients with endometriosis. However, the mechanisms underlying how TGF-β/TGF-β receptor and OCT4 affect endometriotic cell migration still remain largely unknown. Therefore, endometriotic tissue with high cell migratory capacity were collected from patients with adenomyotic myometrium (n = 23) and chocolate cyst (n = 24); and endometrial tissue with low cell migratory capacity in normal endometrium or hyperplastic endometrium (n = 8) were collected as the controls. We found the mRNA levels of TGF-β receptor I (TGF-β RI) and OCT4 were significantly higher in the high-migratory ectopic endometriotic tissues than those of the low-migratory normal or hyperplastic endometrium. Positive correlations between TGF-β RI and OCT4, and either TGF-β RI or OCT4 with migration-related genes (SNAIL, SLUG and TWIST) regarding the mRNA levels were observed in human endometriotic tissues. TGF-βI dose-dependently increased the gene and protein levels of OCT4, SNAIL and N-Cadherin (N-CAD) and silencing of endogenous OCT4 significantly suppressed the TGF-βI-induced expressions of N-CAD and SNAIL in primary human endometriotic stromal cells and human endometrial carcinoma cell lines RL95-2 and HEC1A. Furthermore, TGF-βI significantly increased the migration ability of endometriotic cells and silencing of OCT4 dramatically suppressed the TGF-βI-induced cell migration activity evidenced by wound-closure assay, transwell assay, and confocal image of F-actin cellular distribution. In conclusion, the present findings demonstrate that the niche TGF-β plays a critical role in initiating expressions of pluripotent transcription factor OCT4 which may contribute to the ectopic endometrial growth by stimulating endometrial cell

  5. Co-culture with Sertoli cells promotes proliferation and migration of umbilical cord mesenchymal stem cells

    SciTech Connect

    Zhang, Fenxi; Hong, Yan; Liang, Wenmei; Ren, Tongming; Jing, Suhua; Lin, Juntang

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer Co-culture of Sertoli cells (SCs) with human umbilical cord mesenchymal stem cells (UCMSCs). Black-Right-Pointing-Pointer Presence of SCs dramatically increased proliferation and migration of UCMSCs. Black-Right-Pointing-Pointer Presence of SCs stimulated expression of Mdm2, Akt, CDC2, Cyclin D, CXCR4, MAPKs. -- Abstract: Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of 'nurse' cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neural stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P < 0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.

  6. Vimentin contributes to human mammary epithelial cell migration.

    PubMed

    Gilles, C; Polette, M; Zahm, J M; Tournier, J M; Volders, L; Foidart, J M; Birembaut, P

    1999-12-01

    Vimentin expression in human mammary epithelial MCF10A cells was examined as a function of their migratory status using an in vitro wound-healing model. Analysis of the trajectories of the cells and their migratory speeds by time lapse-video microscopy revealed that vimentin mRNA and protein expression were exclusively induced in cells at the wound's edge which were actively migrating towards the center of the lesion. Actin labeling showed the reorganization of actin filaments in cells at the wound's edge which confirmed the migratory phenotype of this cell subpopulation. Moreover, the vimentin protein disappeared when the cells became stationary after wound closure. Using cells transfected with the vimentin promoter controlling the green fluorescent protein gene, we also demonstrated the specific activation of the vimentin promoter in the migratory cells at the wound's edge. Transfection of the antisense vimentin cDNA into MCF10A cells clearly reduced both their ability to express vimentin and their migratory speed. Taken together, these observations demonstrate that vimentin is transiently associated with, and could be functionally involved in, the migratory status of human epithelial cells.

  7. Argininosuccinate synthetase 1 suppression and arginine restriction inhibit cell migration in gastric cancer cell lines.

    PubMed

    Shan, Yan-Shen; Hsu, Hui-Ping; Lai, Ming-Derg; Yen, Meng-Chi; Chen, Wei-Ching; Fang, Jung-Hua; Weng, Tzu-Yang; Chen, Yi-Ling

    2015-01-01

    Gastric cancer metastasis remains a major cause of cancer-related deaths. There is an urgent need to develop new therapeutic approaches targeting metastatic gastric cancer. Argininosuccinate synthetase 1 (ASS1) expression is increased in gastric cancer. We detected the protein expression of ASS1 in human gastric cancer cell lines (AGS, NCI-N87, and MKN45) and in murine gastric cancer cell lines (3I and 3IB2). We used vector-mediated short hairpin RNA (shRNA) expression to silence ASS1 expression in the MKN45 and 3IB2 cell lines, and analyzed the effects of this protein on cell migration and metastasis. We demonstrated that ASS1 silencing suppressed cell migration in the MKN45 and 3IB2 cell lines. ASS1 knockdown significantly reduced liver metastasis in mice after the intrasplenic implantation of 3IB2 cancer cell clones. To determine whether arginine restriction may represent a therapeutic approach to treat gastric cancer, the sensitivity of tumor cells to arginine depletion was determined in gastric cancer cells. Arginine depletion significantly inhibited cell migration in the gastric cancer cell line. The silencing of ASS1 expression in MKN45 and 3IB2 gastric cancer cells markedly decreased STAT3 protein expression. In conclusion, our results indicate that the ASS1 protein is required for cell migration in gastric cancer cell lines. PMID:25928182

  8. Repositioning "old" drugs for new causes: identifying new inhibitors of prostate cancer cell migration and invasion.

    PubMed

    Shah, Esha T; Upadhyaya, Akanksha; Philp, Lisa K; Tang, Tiffany; Skalamera, Dubravka; Gunter, Jennifer; Nelson, Colleen C; Williams, Elizabeth D; Hollier, Brett G

    2016-04-01

    The majority of prostate cancer (PCa) deaths occur due to the metastatic spread of tumor cells to distant organs. Currently, there is a lack of effective therapies once tumor cells have spread outside the prostate. It is therefore imperative to rapidly develop therapeutics to inhibit the metastatic spread of tumor cells. Gain of cell motility and invasive properties is the first step of metastasis and by inhibiting motility one can potentially inhibit metastasis. Using the drug repositioning strategy, we developed a cell-based multi-parameter primary screening assay to identify drugs that inhibit the migratory and invasive properties of metastatic PC-3 PCa cells. Following the completion of the primary screening assay, 33 drugs were identified from an FDA approved drug library that either inhibited migration or were cytotoxic to the PC-3 cells. Based on the data obtained from the subsequent validation studies, mitoxantrone hydrochloride, simvastatin, fluvastatin and vandetanib were identified as strong candidates that can inhibit both the migration and invasion of PC-3 cells without significantly affecting cell viability. By employing the drug repositioning strategy instead of a de novo drug discovery and development strategy, the identified drug candidates have the potential to be rapidly translated into the clinic for the management of men with aggressive forms of PCa.

  9. Collective migration and cell jamming in asthma, cancer and development.

    PubMed

    Park, Jin-Ah; Atia, Lior; Mitchel, Jennifer A; Fredberg, Jeffrey J; Butler, James P

    2016-09-15

    Collective cellular migration within the epithelial layer impacts upon development, wound healing and cancer invasion, but remains poorly understood. Prevailing conceptual frameworks tend to focus on the isolated role of each particular underlying factor - taken one at a time or at most a few at a time - and thus might not be tailored to describe a cellular collective that embodies a wide palette of physical and molecular interactions that are both strong and complex. To bridge this gap, we shift the spotlight to the emerging concept of cell jamming, which points to only a small set of parameters that govern when a cellular collective might jam and rigidify like a solid, or instead unjam and flow like a fluid. As gateways to cellular migration, the unjamming transition (UJT) and the epithelial-to-mesenchymal transition (EMT) share certain superficial similarities, but their congruence - or lack thereof - remains unclear. In this Commentary, we discuss aspects of cell jamming, its established role in human epithelial cell layers derived from the airways of non-asthmatic and asthmatic donors, and its speculative but emerging roles in development and cancer cell invasion. PMID:27550520

  10. Ganglioside GM2 mediates migration of tumor cells by interacting with integrin and modulating the downstream signaling pathway.

    PubMed

    Kundu, Manjari; Mahata, Barun; Banerjee, Avisek; Chakraborty, Sohini; Debnath, Shibjyoti; Ray, Sougata Sinha; Ghosh, Zhumur; Biswas, Kaushik

    2016-07-01

    The definitive role of ganglioside GM2 in mediating tumor-induced growth and progression is still unknown. Here we report a novel role of ganglioside GM2 in mediating tumor cell migration and uncovered its mechanism. Data shows differential expression levels of GM2-synthase as well as GM2 in different human cancer cells. siRNA mediated knockdown of GM2-synthase in CCF52, A549 and SK-RC-26B cells resulted in significant inhibition of tumor cell migration as well as invasion in vitro without affecting cellular proliferation. Over-expression of GM2-synthase in low-GM2 expressing SK-RC-45 cells resulted in a consequent increase in migration thus confirming the potential role GM2 and its downstream partners play in tumor cell migration and motility. Further, treatment of SK-RC-45 cells with exogenous GM2 resulted in a dramatic increase in migratory and invasive capacity with no change in proliferative capacity, thereby confirming the role of GM2 in tumorigenesis specifically by mediating tumor migration and invasion. Gene expression profiling of GM2-synthase silenced cells revealed altered expression of several genes involved in cell migration primarily those controlling the integrin mediated signaling. GM2-synthase knockdown resulted in decreased phosphorylation of FAK, Src as well as Erk, while over-expression and/or exogenous GM2 treatment caused increased FAK and Erk phosphorylation respectively. Again, GM2 mediated invasion and Erk phosphorylation is blocked in integrin knockdown SK-RC-45 cells, thus confirming that GM2 mediated migration and phosphorylation of Erk is integrin dependent. Finally, confocal microscopy suggested co-localization while co-immunoprecipitation and surface plasmon resonance (SPR) confirmed direct interaction of membrane bound ganglioside, GM2 with the integrin receptor. PMID:27066976

  11. Ganglioside GM2 mediates migration of tumor cells by interacting with integrin and modulating the downstream signaling pathway.

    PubMed

    Kundu, Manjari; Mahata, Barun; Banerjee, Avisek; Chakraborty, Sohini; Debnath, Shibjyoti; Ray, Sougata Sinha; Ghosh, Zhumur; Biswas, Kaushik

    2016-07-01

    The definitive role of ganglioside GM2 in mediating tumor-induced growth and progression is still unknown. Here we report a novel role of ganglioside GM2 in mediating tumor cell migration and uncovered its mechanism. Data shows differential expression levels of GM2-synthase as well as GM2 in different human cancer cells. siRNA mediated knockdown of GM2-synthase in CCF52, A549 and SK-RC-26B cells resulted in significant inhibition of tumor cell migration as well as invasion in vitro without affecting cellular proliferation. Over-expression of GM2-synthase in low-GM2 expressing SK-RC-45 cells resulted in a consequent increase in migration thus confirming the potential role GM2 and its downstream partners play in tumor cell migration and motility. Further, treatment of SK-RC-45 cells with exogenous GM2 resulted in a dramatic increase in migratory and invasive capacity with no change in proliferative capacity, thereby confirming the role of GM2 in tumorigenesis specifically by mediating tumor migration and invasion. Gene expression profiling of GM2-synthase silenced cells revealed altered expression of several genes involved in cell migration primarily those controlling the integrin mediated signaling. GM2-synthase knockdown resulted in decreased phosphorylation of FAK, Src as well as Erk, while over-expression and/or exogenous GM2 treatment caused increased FAK and Erk phosphorylation respectively. Again, GM2 mediated invasion and Erk phosphorylation is blocked in integrin knockdown SK-RC-45 cells, thus confirming that GM2 mediated migration and phosphorylation of Erk is integrin dependent. Finally, confocal microscopy suggested co-localization while co-immunoprecipitation and surface plasmon resonance (SPR) confirmed direct interaction of membrane bound ganglioside, GM2 with the integrin receptor.

  12. Probing Leader Cells in Endothelial Collective Migration by Plasma Lithography Geometric Confinement

    PubMed Central

    Yang, Yongliang; Jamilpour, Nima; Yao, Baoyin; Dean, Zachary S.; Riahi, Reza; Wong, Pak Kin

    2016-01-01

    When blood vessels are injured, leader cells emerge in the endothelium to heal the wound and restore the vasculature integrity. The characteristics of leader cells during endothelial collective migration under diverse physiological conditions, however, are poorly understood. Here we investigate the regulation and function of endothelial leader cells by plasma lithography geometric confinement generated. Endothelial leader cells display an aggressive phenotype, connect to follower cells via peripheral actin cables and discontinuous adherens junctions, and lead migrating clusters near the leading edge. Time-lapse microscopy, immunostaining, and particle image velocimetry reveal that the density of leader cells and the speed of migrating clusters are tightly regulated in a wide range of geometric patterns. By challenging the cells with converging, diverging and competing patterns, we show that the density of leader cells correlates with the size and coherence of the migrating clusters. Collectively, our data provide evidence that leader cells control endothelial collective migration by regualting the migrating clusters. PMID:26936382

  13. Probing Leader Cells in Endothelial Collective Migration by Plasma Lithography Geometric Confinement.

    PubMed

    Yang, Yongliang; Jamilpour, Nima; Yao, Baoyin; Dean, Zachary S; Riahi, Reza; Wong, Pak Kin

    2016-03-03

    When blood vessels are injured, leader cells emerge in the endothelium to heal the wound and restore the vasculature integrity. The characteristics of leader cells during endothelial collective migration under diverse physiological conditions, however, are poorly understood. Here we investigate the regulation and function of endothelial leader cells by plasma lithography geometric confinement generated. Endothelial leader cells display an aggressive phenotype, connect to follower cells via peripheral actin cables and discontinuous adherens junctions, and lead migrating clusters near the leading edge. Time-lapse microscopy, immunostaining, and particle image velocimetry reveal that the density of leader cells and the speed of migrating clusters are tightly regulated in a wide range of geometric patterns. By challenging the cells with converging, diverging and competing patterns, we show that the density of leader cells correlates with the size and coherence of the migrating clusters. Collectively, our data provide evidence that leader cells control endothelial collective migration by regualting the migrating clusters.

  14. Probing Leader Cells in Endothelial Collective Migration by Plasma Lithography Geometric Confinement

    NASA Astrophysics Data System (ADS)

    Yang, Yongliang; Jamilpour, Nima; Yao, Baoyin; Dean, Zachary S.; Riahi, Reza; Wong, Pak Kin

    2016-03-01

    When blood vessels are injured, leader cells emerge in the endothelium to heal the wound and restore the vasculature integrity. The characteristics of leader cells during endothelial collective migration under diverse physiological conditions, however, are poorly understood. Here we investigate the regulation and function of endothelial leader cells by plasma lithography geometric confinement generated. Endothelial leader cells display an aggressive phenotype, connect to follower cells via peripheral actin cables and discontinuous adherens junctions, and lead migrating clusters near the leading edge. Time-lapse microscopy, immunostaining, and particle image velocimetry reveal that the density of leader cells and the speed of migrating clusters are tightly regulated in a wide range of geometric patterns. By challenging the cells with converging, diverging and competing patterns, we show that the density of leader cells correlates with the size and coherence of the migrating clusters. Collectively, our data provide evidence that leader cells control endothelial collective migration by regualting the migrating clusters.

  15. Dysregulated expression of IDO may cause unexplained recurrent spontaneous abortion through suppression of trophoblast cell proliferation and migration.

    PubMed

    Zong, Shanshan; Li, Chunqing; Luo, Chengfeng; Zhao, Xin; Liu, Chunhong; Wang, Kai; Jia, Wenwen; Bai, Mingliang; Yin, Minghong; Bao, Shihua; Guo, Jie; Kang, Jiuhong; Duan, Tao; Zhou, Qian

    2016-01-27

    In pregnancy, trophoblast proliferation, migration and invasion are important for the establishment and maintenance of a successful pregnancy. Impaired trophoblast function has been implicated in recurrent spontaneous abortion (RSA), a major complication of pregnancy, but the underlying mechanisms remain unclear. Indoleamine 2,3-dioxygenase (IDO), an enzyme that catabolizes tryptophan along the kynurenine pathway, is highly expressed in the placenta and serum during pregnancy. Here, we identified a novel function of IDO in regulating trophoblast cell proliferation and migration. We showed that IDO expression and activity were decreased in unexplained recurrent spontaneous abortion (URSA) compared to normal pregnancy. Furthermore, blocking IDO in human trophoblast cells led to reduced proliferation and migration, along with decreased STAT3 phosphorylation and MMP9 expression. Increased STAT3 phosphorylation reversed the IDO knockdown-suppressed trophoblast cell proliferation and migration. In addition, the overexpression of IDO promoted cell proliferation and migration, which could be abolished by the STAT3 signaling inhibitor (AG490). Finally, we observed similar reductions of STAT3 phosphorylation and MMP9 expression in URSA patients. These results indicate that the level of IDO expression may be associated with pregnancy-related complications, such as URSA, by affecting trophoblast cell proliferation and migration via the STAT3 signaling pathway.

  16. The migrations of Drosophila muscle founders and primordial germ cells are interdependent.

    PubMed

    Stepanik, Vincent; Dunipace, Leslie; Bae, Young-Kyung; Macabenta, Frank; Sun, Jingjing; Trisnadi, Nathanie; Stathopoulos, Angelike

    2016-09-01

    Caudal visceral mesoderm (CVM) cells migrate from posterior to anterior of the Drosophila embryo as two bilateral streams of cells to support the specification of longitudinal muscles along the midgut. To accomplish this long-distance migration, CVM cells receive input from their environment, but little is known about how this collective cell migration is regulated. In a screen we found that wunen mutants exhibit CVM cell migration defects. Wunens are lipid phosphate phosphatases known to regulate the directional migration of primordial germ cells (PGCs). PGC and CVM cell types interact while PGCs are en route to the somatic gonadal mesoderm, and previous studies have shown that CVM impacts PGC migration. In turn, we found here that CVM cells exhibit an affinity for PGCs, localizing to the position of PGCs whether mislocalized or trapped in the endoderm. In the absence of PGCs, CVM cells exhibit subtle changes, including more cohesive movement of the migrating collective, and an increased number of longitudinal muscles is found at anterior sections of the larval midgut. These data demonstrate that PGC and CVM cell migrations are interdependent and suggest that distinct migrating cell types can coordinately influence each other to promote effective cell migration during development. PMID:27578182

  17. To The Abercrombie Meeting and back again: a journey into the world of cell migration.

    PubMed

    Makowska, Katarzyna Anna

    2013-01-01

    The 7th Abercrombie Meeting took place in Oxford this past summer. It was organized by The Royal Microscopical Society with the support of The British Society for Cell Biology. Michael Abercrombie was a pioneer in the field of investigating cell behavior using time-lapse microscopy. The meeting was focused on "multi-dimensional cell migration in development and disease" and it brought together many of the world's leading researchers in the area, providing an opportunity to discuss the very latest advances and possible future developments in the field. The meeting sessions included Invasive Migration, Invasive Adhesions in Migrating Cells, Signaling in Migration, Immune Cell Migration, Migrations during Morphogenesis and Migration and Disease. As with all Abercrombie meetings, the conference delegates were treated to a staggering array of live cell imaging, in vivo imaging and images generated by the latest developments in microscopy.

  18. Hsc70 regulates cell surface ASIC2 expression and vascular smooth muscle cell migration.

    PubMed

    Grifoni, Samira C; McKey, Susan E; Drummond, Heather A

    2008-05-01

    Recent studies suggest members of the degenerin (DEG)/epithelial Na(+) channel (ENaC)/acid-sensing ion channel (ASIC) protein family play an important role in vascular smooth muscle cell (VSMC) migration. In a previous investigation, we found suppression of a certain DEG/ENaC/ASIC member, ASIC2, increased VSMC chemotactic migration, raising the possibility that ASIC2 may play an inhibitory role. Because ASIC2 protein was retained in the cytoplasm, we reasoned increasing surface expression of ASIC2 might unmask the inhibitory role of ASIC2 in VSMC migration so we could test the hypothesis that ASIC2 inhibits VSMC migration. Therefore, we used the chemical chaperone glycerol to enhance ASIC2 expression. Glycerol 1) increased cytoplasm ASIC2 expression, 2) permitted detection of ASIC2 at the cell surface, and 3) inhibited platelet-derived growth factor (PDGF)-bb mediated VSMC migration. Furthermore, ASIC2 silencing completely abolished the inhibitory effect of glycerol on migration, suggesting upregulation of ASIC2 is responsible for glycerol-induced inhibition of VSMC migration. Because other investigators have shown that glycerol regulates ENaC/ASIC via interactions with a certain heat shock protein, heat shock protein 70 (Hsc70), we wanted to determine the importance of Hsc70 on ASIC2 expression in VSMCs. We found that Hsc70 silencing increases ASIC2 cell surface expression and inhibits VSMC migration, which is abolished by cosilencing ASIC2. These data demonstrate that Hsc70 inhibits ASIC2 expression, and, when the inhibitory effect of Hsc70 is removed, ASIC2 expression increases, resulting in reduced VSMC migration. Because VSMC migration contributes to vasculogenesis and remodeling following vascular injury, our findings raise the possibility that ASIC2-Hsc70 interactions may play a role in these processes. PMID:18310515

  19. Time-lapse microscopy and image processing for stem cell research: modeling cell migration

    NASA Astrophysics Data System (ADS)

    Gustavsson, Tomas; Althoff, Karin; Degerman, Johan; Olsson, Torsten; Thoreson, Ann-Catrin; Thorlin, Thorleif; Eriksson, Peter

    2003-05-01

    This paper presents hardware and software procedures for automated cell tracking and migration modeling. A time-lapse microscopy system equipped with a computer controllable motorized stage was developed. The performance of this stage was improved by incorporating software algorithms for stage motion displacement compensation and auto focus. The microscope is suitable for in-vitro stem cell studies and allows for multiple cell culture image sequence acquisition. This enables comparative studies concerning rate of cell splits, average cell motion velocity, cell motion as a function of cell sample density and many more. Several cell segmentation procedures are described as well as a cell tracking algorithm. Statistical methods for describing cell migration patterns are presented. In particular, the Hidden Markov Model (HMM) was investigated. Results indicate that if the cell motion can be described as a non-stationary stochastic process, then the HMM can adequately model aspects of its dynamic behavior.

  20. Inhibition of Src family kinases with dasatinib blocks migration and invasion of human melanoma cells.

    PubMed

    Buettner, Ralf; Mesa, Tania; Vultur, Adina; Lee, Frank; Jove, Richard

    2008-11-01

    Src family kinases (SFK) are involved in regulating a multitude of biological processes, including cell adhesion, migration, proliferation, and survival, depending on the cellular context. Therefore, although SFKs are currently being investigated as potential targets for treatment strategies in various cancers, the biological responses to inhibition of SFK signaling in any given tumor type are not predictable. Dasatinib (BMS-354825) is a dual Src/Abl kinase inhibitor with potent antiproliferative activity against hematologic malignancies harboring activated BCR-ABL. In this study, we show that dasatinib blocks migration and invasion of human melanoma cells without affecting proliferation and survival. Moreover, dasatinib completely inhibits SFK kinase activity at low nanomolar concentrations in all eight human melanoma cell lines investigated. In addition, two known downstream targets of SFKs, focal adhesion kinase and Crk-associated substrate (p130(CAS)), are inhibited with similar concentrations and kinetics. Consistent with inhibition of these signaling pathways and invasion, dasatinib down-regulates expression of matrix metalloproteinase-9. We also provide evidence that dasatinib directly inhibits kinase activity of the EphA2 receptor tyrosine kinase, which is overexpressed and/or overactive in many solid tumors, including melanoma. Thus, SFKs and downstream signaling are implicated as having key roles in migration and invasion of melanoma cells.

  1. Interplay of RhoA and mechanical forces in collective cell migration driven by leader cells.

    PubMed

    Reffay, M; Parrini, M C; Cochet-Escartin, O; Ladoux, B; Buguin, A; Coscoy, S; Amblard, F; Camonis, J; Silberzan, P

    2014-03-01

    The leading front of a collectively migrating epithelium often destabilizes into multicellular migration fingers where a cell initially similar to the others becomes a leader cell while its neighbours do not alter. The determinants of these leader cells include mechanical and biochemical cues, often under the control of small GTPases. However, an accurate dynamic cartography of both mechanical and biochemical activities remains to be established. Here, by mapping the mechanical traction forces exerted on the surface by MDCK migration fingers, we show that these structures are mechanical global entities with the leader cells exerting a large traction force. Moreover, the spatial distribution of RhoA differential activity at the basal plane strikingly mirrors this force cartography. We propose that RhoA controls the development of these fingers through mechanical cues: the leader cell drags the structure and the peripheral pluricellular acto-myosin cable prevents the initiation of new leader cells.

  2. Glioma migration: clues from the biology of neural progenitor cells and embryonic CNS cell migration.

    PubMed

    Dirks, P B

    2001-06-01

    Neural stem cells have recently come to the forefront in neurobiology because of the possibilities for CNS repair by transplantation. Further understanding of the biology of these cells is critical for making their use in CNS repair possible. It is likely that these discoveries will also have spin-offs for neuro-oncology as primary brain tumors may arise from a CNS progenitor cell. An understanding of the normal migratory ability of these cells is also likely to have a very important impact on the knowledge of brain tumor invasion.

  3. Collective epithelial cell sheet adhesion and migration on polyelectrolyte multilayers with uniform and gradients of compliance.

    PubMed

    Martinez, Jessica S; Schlenoff, Joseph B; Keller, Thomas C S

    2016-08-01

    Polyelectrolyte multilayers (PEMUs) are tunable thin films that could serve as coatings for biomedical implants. PEMUs built layer by layer with the polyanion poly(acrylic acid) (PAA) modified with a photosensitive 4-(2-hydroxyethoxy) benzophenone (PAABp) group and the polycation poly(allylamine hydrochloride) (PAH) are mechanically tunable by UV irradiation, which forms covalent bonds between the layers and increases PEMU stiffness. PAH-terminated PEMUs (PAH-PEMUs) that were uncrosslinked, UV-crosslinked to a uniform stiffness, or UV-crosslinked with an edge mask or through a neutral density optical gradient filter to form continuous compliance gradients were used to investigate how differences in PEMU stiffness affect the adhesion and migration of epithelial cell sheets from scales of the fish Poecilia sphenops (Black Molly) and Carassius auratus (Comet Goldfish). During the progressive collective cell migration, the edge cells (also known as 'leader' cells) in the sheets on softer uncrosslinked PEMUs and less crosslinked regions of the gradient formed more actin filaments and vinculin-containing adherens junctions and focal adhesions than formed in the sheet cells on stiffer PEMUs or glass. During sheet migration, the ratio of edge cell to internal cell (also known as 'follower' cells) motilities were greater on the softer PEMUs than on the stiffer PEMUs or glass, causing tension to develop across the sheet and periods of retraction, during which the edge cells lost adhesion to the substrate and regions of the sheet retracted toward the more adherent internal cell region. These retraction events were inhibited by the myosin II inhibitor Blebbistatin, which reduced the motility velocity ratios to those for sheets on the stiffer PEMUs. Blebbistatin also caused disassembly of actin filaments, reorganization of focal adhesions, increased cell spreading at the leading edge, as well as loss of edge cell-cell connections in epithelial cell sheets on all surfaces

  4. Notch1-Dll4 signalling and mechanical force regulate leader cell formation during collective cell migration.

    PubMed

    Riahi, Reza; Sun, Jian; Wang, Shue; Long, Min; Zhang, Donna D; Wong, Pak Kin

    2015-03-13

    At the onset of collective cell migration, a subset of cells within an initially homogenous population acquires a distinct 'leader' phenotype with characteristic morphology and motility. However, the factors driving the leader cell formation as well as the mechanisms regulating leader cell density during the migration process remain to be determined. Here we use single-cell gene expression analysis and computational modelling to show that the leader cell identity is dynamically regulated by Dll4 signalling through both Notch1 and cellular stress in a migrating epithelium. Time-lapse microscopy reveals that Dll4 is induced in leader cells after the creation of the cell-free region and leader cells are regulated via Notch1-Dll4 lateral inhibition. Furthermore, mechanical stress inhibits Dll4 expression and leader cell formation in the monolayer. Collectively, our findings suggest that a reduction of mechanical force near the boundary promotes Notch1-Dll4 signalling to dynamically regulate the density of leader cells during collective cell migration.

  5. Inhibition of Kv channel expression by NSAIDs depolarizes membrane potential and inhibits cell migration by disrupting calpain signaling.

    PubMed

    Silver, Kristopher; Littlejohn, Alaina; Thomas, Laurel; Marsh, Elizabeth; Lillich, James D

    2015-12-15

    Clinical use of non-steroidal anti-inflammatory drugs (NSAIDs) is well known to cause gastrointestinal ulcer formation via several mechanisms that include inhibiting epithelial cell migration and mucosal restitution. The drug-affected signaling pathways that contribute to inhibition of migration by NSAIDs are poorly understood, though previous studies have shown that NSAIDs depolarize membrane potential and suppress expression of calpain proteases and voltage-gated potassium (Kv) channel subunits. Kv channels play significant roles in cell migration and are targets of NSAID activity in white blood cells, but the specific functional effects of NSAID-induced changes in Kv channel expression, particularly on cell migration, are unknown in intestinal epithelial cells. Accordingly, we investigated the effects of NSAIDs on expression of Kv1.3, 1.4, and 1.6 in vitro and/or in vivo and evaluated the functional significance of loss of Kv subunit expression. Indomethacin or NS-398 reduced total and plasma membrane protein expression of Kv1.3 in cultured intestinal epithelial cells (IEC-6). Additionally, depolarization of membrane potential with margatoxin (MgTx), 40mM K(+), or silencing of Kv channel expression with siRNA significantly reduced IEC-6 cell migration and disrupted calpain activity. Furthermore, in rat small intestinal epithelia, indomethacin and NS-398 had significant, yet distinct, effects on gene and protein expression of Kv1.3, 1.4, or 1.6, suggesting that these may be clinically relevant targets. Our results show that inhibition of epithelial cell migration by NSAIDs is associated with decreased expression of Kv channel subunits, and provide a mechanism through which NSAIDs inhibit cell migration and may contribute to NSAID-induced gastrointestinal (GI) toxicity.

  6. Critical Role of Spns2, a Sphingosine-1-Phosphate Transporter, in Lung Cancer Cell Survival and Migration

    PubMed Central

    Bradley, Eric; Dasgupta, Somsankar; Jiang, Xue; Zhao, Xiaying; Zhu, Gu; He, Qian; Dinkins, Michael; Bieberich, Erhard; Wang, Guanghu

    2014-01-01

    The sphingosine-1-phosphate (S1P) transporter Spns2 regulates myocardial precursor migration in zebrafish and lymphocyte trafficking in mice. However, its function in cancer has not been investigated. We show here that ectopic Spns2 expression induced apoptosis and its knockdown enhanced cell migration in non-small cell lung cancer (NSCLC) cells. Metabolically, Spns2 expression increased the extracellular S1P level while its knockdown the intracellular. Pharmacological inhibition of S1P synthesis abolished the augmented cell migration mediated by Spns2 knockdown, indicating that intracellular S1P plays a key role in this process. Cell signaling studies indicated that Spns2 expression impaired GSK-3β and Stat3 mediated pro-survival pathways. Conversely, these pathways were activated by Spns2 knockdown, which explains the increased cell migration since they are also crucial for migration. Alterations of Spns2 were found to affect several enzymes involved in S1P metabolism, including sphingosine kinases, S1P phosphatases, and S1P lyase 1. Genetically, Spns2 mRNA level was found to be reduced in advanced lung cancer (LC) patients as quantified by using a small scale qPCR array. These data show for the first time that Spns2 plays key roles in regulating the cellular functions in NSCLC cells, and that its down-regulation is a potential risk factor for LC. PMID:25330231

  7. Lipocalin 2 Enhances Migration and Resistance against Cisplatin in Endometrial Carcinoma Cells

    PubMed Central

    Kashima, Hiroyasu; Yamada, Yasushi; Kobara, Hisanori; Asaka, Ryoichi; Ando, Hirofumi; Higuchi, Shotaro; Ida, Koichi; Mvunta, David Hamisi; Shiozawa, Tanri

    2016-01-01

    Purpose Lipocalin 2 (LCN2) is a secretory protein that is involved in various physiological processes including iron transport. We previously identified LCN2 as an up-regulated gene in endometrial carcinoma, and found that the overexpression of LCN2 and its receptor, SLC22A17, was associated with a poor prognosis. However, the functions and mechanism of action of LCN2 currently remain unclear. Methods The LCN2-overexpressing endometrial carcinoma cell lines, HHUA and RL95-2, and LCN2-low-expressing one, HEC1B, were used. The effects of LCN2 on cell migration, cell viability, and apoptosis under various stresses, including ultraviolet (UV) irradiation and cisplatin treatment, were examined using the scratch wound healing assay, WST-1 assay, and Apostrand assay, respectively. Results LCN2-silencing using shRNA method significantly reduced the migration ability of cells (p<0.05). Cytotoxic stresses significantly decreased the viability of LCN2-silenced cells more than that of control cells. In contrast, LCN2 overexpression was significantly increased cisplatin resistance. These effects were canceled by the addition of the iron chelator, deferoxamine. After UV irradiation, the expression of phosphorylated Akt (pAkt) was decreased in LCN2-silenced cells, and the PI3K inhibitor canceled the difference induced in UV sensitivity by LCN2. The cisplatin-induced expression of pAkt was not affected by LCN2; however, the expression of p53 and p21 was increased by LCN2-silencing. Conclusions These results indicated that LCN2 was involved in the migration and survival of endometrial carcinoma cells under various stresses in an iron-dependent manner. The survival function of LCN2 may be exerted through the PI3K pathway and suppression of the p53-p21 pathway. These functions of LCN2 may increase the malignant potential of endometrial carcinoma cells. PMID:27168162

  8. Migration of Langerhans cells and gammadelta dendritic cells from UV-B-irradiated sheep skin.

    PubMed

    Dandie, G W; Clydesdale, G J; Radcliff, F J; Muller, H K

    2001-02-01

    Depletion of dendritic cells from UV-B-irradiated sheep skin was investigated by monitoring migration of these cells towards regional lymph nodes. By creating and cannulating pseudoafferent lymphatic vessels draining a defined region of skin, migrating cells were collected and enumerated throughout the response to UV-B irradiation. In the present study, the effects of exposing sheep flank skin to UV-B radiation clearly demonstrated a dose-dependent increase in the migration of Langerhans cells (LC) from the UV-B-exposed area to the draining lymph node. The range of UV-B doses assessed in this study included 2.7 kJ/m2, a suberythemal dose; 8 kJ/m2, 1 minimal erythemal dose (MED); 20.1 kJ/m2; 40.2 kJ/m2; and 80.4 kJ/m2, 10 MED. The LC were the cells most sensitive to UV-B treatment, with exposure to 8 kJ/m2 or greater reproducibly causing a significant increase in migration. Migration of gammadelta+ dendritic cells (gammadelta+ DC) from irradiated skin was also triggered by exposure to UV-B radiation, but dose dependency was not evident within the range of UV-B doses examined. This, in conjunction with the lack of any consistent correlation between either the timing or magnitude of migration peaks of these two cell types, suggests that different mechanisms govern the egress of LC and gammadelta+ DC from the skin. It is concluded that the depression of normal immune function in the skin after exposure to erythemal doses of UV-B radiation is associated with changes in the migration patterns of epidermal dendritic cells to local lymph nodes. PMID:11168622

  9. Enhanced Migration of Neural Stem Cells by Microglia Grown on a Three-Dimensional Graphene Scaffold.

    PubMed

    Jiang, Ziyun; Song, Qin; Tang, Mingliang; Yang, Lingyan; Cheng, Yilin; Zhang, Min; Xu, Dongsheng; Cheng, Guosheng

    2016-09-28

    One of the key challenges in engineering neural tissues for cell-based therapies is to develop a biocompatible scaffold material to direct neural stem cell (NSC) behaviors. One great advantage for a scaffold would be to induce NSC migration toward pathological sites during regeneration and repair. In particular, the inflammatory responses in the pathological zone, which are mainly mediated by microglia in the central nervous system, affect the repair capacity of NSCs through NSC migration. Recently, graphene was used as a neural interface and scaffold material, but few studies have addressed the relationship between microglia and NSCs in a graphene culture system. In this study, we used a combination of immunofluorescence, Western blotting, enzyme-linked immunosorbent assays, and scanning electron microscopy to investigate how conditioned medium (CM) produced from microglia grown on two-dimensional graphene (2D-G) films or three-dimensional graphene (3D-G) foams govern NSC migration. The results revealed that the CM produced by microglia grown in 3D-G cultures could promote neurosphere formation, facilitate NSC migration from the neurospheres, and increase single cell polarization by activating the stromal cell-derived factor 1 α (SDF-1α)/CXC chemokine receptor 4 (CXCR4) signaling pathway and enhancing cell adhesion on the substrate. By contrast, the 2D-G CM failed to achieve these results. Our study suggests the great potential of 3D-G as a neural scaffold for NSC-based therapy in tissue engineering and regenerative medicine. PMID:27589088

  10. Actin-Based Feedback Circuits in Cell Migration and Endocytosis

    NASA Astrophysics Data System (ADS)

    Wang, Xinxin

    In this thesis, we study the switch and pulse functions of actin during two important cellular processes, cell migration and endocytosis. Actin is an abundant protein that can polymerize to form a dendritic network. The actin network can exert force to push or bend the cell membrane. During cell migration, the actin network behaves like a switch, assembling mostly at one end or at the other end. The end with the majority of the actin network is the leading edge, following which the cell can persistently move in the same direction. The other end, with the minority of the actin network, is the trailing edge, which is dragged by the cell as it moves forward. When subjected to large fluctuations or external stimuli, the leading edge and the trailing edge can interchange and change the direction of motion, like a motion switch. Our model of the actin network in a cell reveals that mechanical force is crucial for forming the motion switch. We find a transition from single state symmetric behavior to switch behavior, when tuning parameters such as the force. The model is studied by both stochastic simulations, and a set of rate equations that are consistent with the simulations. Endocytosis is a process by which cells engulf extracellular substances and recycle the cell membrane. In yeast cells, the actin network is transiently needed to overcome the pressure difference across the cell membrane caused by turgor pressure. The actin network behaves like a pulse, which assembles and then disassembles within about 30 seconds. Using a stochastic model, we reproduce the pulse behaviors of the actin network and one of its regulatory proteins, Las17. The model matches green fluorescence protein (GFP) experiments for wild-type cells. The model also predicts some phenotypes that modify or diminish the pulse behavior. The phenotypes are verified with both experiments performed at Washington University and with other groups' experiments. We find that several feedback mechanisms are

  11. MicroRNA-383 expression regulates proliferation, migration, invasion, and apoptosis in human glioma cells.

    PubMed

    Xu, Dawei; Ma, Pengju; Gao, Guojun; Gui, Yongkun; Niu, Xiaolu; Jin, Baozhe

    2015-09-01

    This study aims to evaluate microRNA-383 (miR-383) expression level in glioma cells and its influences on proliferation, migration, invasion, apoptosis, and cell cycle in glioma cells. miR-383 expression levels were determined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Thirty BALB/c-nu mice were randomly assigned into three groups: U87-miR-383 group, vector-control group, and blank group. Tumorigenicity experiment was conducted to confirm the function of miR-383. U251 and U87 glioma cells were divided into three groups: non-transfected control cells (NT group), glioma cells transfected with miR-383 (miR-383 group), and glioma cells transfected with negative sequence (NC group). Transfection efficiency was measured by qRT-PCR. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Cell migration and invasion were examined by utilizing a Transwell chamber. Cell cycle and apoptosis were analyzed by flow cytometry. The qRT-PCR results revealed that miR-383 expression was down-regulated in human glioma cells, and was negatively related to the pathological grading of glioma. The rates of tumor growth in vector-control group and blank group were significantly faster than that in U87-miR-383 group, and the average tumor volume and weight in vector-control group and blank group were increased as compared with U87-miR-383 group. Additionally, miR-383 levels in miR-383 group were higher than those in NT group and NC group. CCK-8 assay indicated lower cell viability in miR-383 group as compared with NT group and NC group. Flow cytometry implied that the percentages of cells in miR-383 group reduced, while the cell apoptosis rate enhanced compared with NT group and NC group. In conclusion, our findings suggest that miR-383 expression is down-regulated in glioma cells, inhibiting cell proliferation, migration, and invasion, affecting the cell cycle, and inducing cell apoptosis.

  12. MicroRNA-383 expression regulates proliferation, migration, invasion, and apoptosis in human glioma cells.

    PubMed

    Xu, Dawei; Ma, Pengju; Gao, Guojun; Gui, Yongkun; Niu, Xiaolu; Jin, Baozhe

    2015-09-01

    This study aims to evaluate microRNA-383 (miR-383) expression level in glioma cells and its influences on proliferation, migration, invasion, apoptosis, and cell cycle in glioma cells. miR-383 expression levels were determined by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). Thirty BALB/c-nu mice were randomly assigned into three groups: U87-miR-383 group, vector-control group, and blank group. Tumorigenicity experiment was conducted to confirm the function of miR-383. U251 and U87 glioma cells were divided into three groups: non-transfected control cells (NT group), glioma cells transfected with miR-383 (miR-383 group), and glioma cells transfected with negative sequence (NC group). Transfection efficiency was measured by qRT-PCR. Cell counting kit-8 (CCK-8) assay was used to detect cell proliferation. Cell migration and invasion were examined by utilizing a Transwell chamber. Cell cycle and apoptosis were analyzed by flow cytometry. The qRT-PCR results revealed that miR-383 expression was down-regulated in human glioma cells, and was negatively related to the pathological grading of glioma. The rates of tumor growth in vector-control group and blank group were significantly faster than that in U87-miR-383 group, and the average tumor volume and weight in vector-control group and blank group were increased as compared with U87-miR-383 group. Additionally, miR-383 levels in miR-383 group were higher than those in NT group and NC group. CCK-8 assay indicated lower cell viability in miR-383 group as compared with NT group and NC group. Flow cytometry implied that the percentages of cells in miR-383 group reduced, while the cell apoptosis rate enhanced compared with NT group and NC group. In conclusion, our findings suggest that miR-383 expression is down-regulated in glioma cells, inhibiting cell proliferation, migration, and invasion, affecting the cell cycle, and inducing cell apoptosis. PMID:25936342

  13. Mathematical model for the effects of adhesion and mechanics on cell migration speed.

    PubMed Central

    DiMilla, P A; Barbee, K; Lauffenburger, D A

    1991-01-01

    Migration of mammalian blood and tissue cells over adhesive surfaces is apparently mediated by specific reversible reactions between cell membrane adhesion receptors and complementary ligands attached to the substratum. Although in a number of systems these receptors and ligand molecules have been isolated and identified, a theory capable of predicting the effects of their properties on cell migration behavior currently does not exist. We present a simple mathematical model for elucidating the dependence of cell speed on adhesion-receptor/ligand binding and cell mechanical properties. Our model can be applied to propose answers to questions such as: does an optimal adhesiveness exist for cell movement? How might changes in receptor and ligand density and/or affinity affect the rate of migration? Can cell rheological properties influence movement speed? This model incorporates cytoskeletal force generation, cell polarization, and dynamic adhesion as requirements for persistent cell movement. A critical feature is the proposed existence of an asymmetry in some cell adhesion-receptor property, correlated with cell polarity. We consider two major alternative mechanisms underlying this asymmetry: (a) a spatial distribution of adhesion-receptor number due to polarized endocytic trafficking and (b) a spatial variation in adhesion-receptor/ligand bond strength. Applying a viscoelastic-solid model for cell mechanics allows us to represent one-dimensional locomotion with a system of differential equations describing cell deformation and displacement along with adhesion-receptor dynamics. In this paper, we solve these equations under the simplifying assumption that receptor dynamics are at a quasi-steady state relative to cell locomotion. Thus, our results are strictly valid for sufficiently slow cell movement, as typically observed for tissue cells such as fibroblasts. Numerical examples relevant to experimental systems are provided. Our results predict how cell speed might

  14. Selective migration of neuralized embryonic stem cells to stem cell factor and media conditioned by glioma cell lines

    PubMed Central

    Serfozo, Peter; Schlarman, Maggie S; Pierret, Chris; Maria, Bernard L; Kirk, Mark D

    2006-01-01

    Background Pluripotent mouse embryonic stem (ES) cells can be induced in vitro to become neural progenitors. Upon transplantation, neural progenitors migrate toward areas of damage and inflammation in the CNS. We tested whether undifferentiated and neuralized mouse ES cells migrate toward media conditioned by glioma cell lines (C6, U87 & N1321) or Stem Cell Factor (SCF). Results Cell migration assays revealed selective migration by neuralized ES cells to conditioned media as well as to synthetic SCF. Migration of undifferentiated ES cells was extensive, but not significantly different from that of controls (Unconditioned Medium). RT-PCR analysis revealed that all the three tumor cell lines tested synthesized SCF and that both undifferentiated and neuralized ES cells expressed c-kit, the receptor for SCF. Conclusion Our results demonstrate that undifferentiated ES cells are highly mobile and that neural progenitors derived from ES cells are selectively attracted toward factors produced by gliomas. Given that the glioma cell lines synthesize SCF, SCF may be one of several factors that contribute to the selective migration observed. PMID:16436212

  15. Role of medullary progenitor cells in epithelial cell migration and proliferation

    PubMed Central

    Chen, Dong; Chen, Zhiyong; Zhang, Yuning; Park, Chanyoung; Al-Omari, Ahmed

    2014-01-01

    This study is aimed at characterizing medullary interstitial progenitor cells and to examine their capacity to induce tubular epithelial cell migration and proliferation. We have isolated a progenitor cell side population from a primary medullary interstitial cell line. We show that the medullary progenitor cells (MPCs) express CD24, CD44, CXCR7, CXCR4, nestin, and PAX7. MPCs are CD34 negative, which indicates that they are not bone marrow-derived stem cells. MPCs survive >50 passages, and when grown in epithelial differentiation medium develop phenotypic characteristics of epithelial cells. Inner medulla collecting duct (IMCD3) cells treated with conditioned medium from MPCs show significantly accelerated cell proliferation and migration. Conditioned medium from PGE2-treated MPCs induce tubule formation in IMCD3 cells grown in 3D Matrigel. Moreover, most of the MPCs express the pericyte marker PDGFR-b. Our study shows that the medullary interstitium harbors a side population of progenitor cells that can differentiate to epithelial cells and can stimulate tubular epithelial cell migration and proliferation. The findings of this study suggest that medullary pericyte/progenitor cells may play a critical role in collecting duct cell injury repair. PMID:24808539

  16. Extravillous trophoblast cells-derived exosomes promote vascular smooth muscle cell migration

    PubMed Central

    Salomon, Carlos; Yee, Sarah; Scholz-Romero, Katherin; Kobayashi, Miharu; Vaswani, Kanchan; Kvaskoff, David; Illanes, Sebastian E.; Mitchell, Murray D.; Rice, Gregory E.

    2014-01-01

    Background: Vascular smooth muscle cells (VSMCs) migration is a critical process during human uterine spiral artery (SpA) remodeling and a successful pregnancy. Extravillous trophoblast cells (EVT) interact with VSMC and enhance their migration, however, the mechanisms by which EVT remodel SpA remain to be fully elucidated. We hypothesize that exosomes released from EVT promote VSMC migration. Methods: JEG-3 and HTR-8/SVneo cell lines were used as models for EVT. Cells were cultured at 37°C and humidified under an atmosphere of 5% CO2-balanced N2 to obtain 8% O2. Cell-conditioned media were collected, and exosomes (exo-JEG-3 and exo- HTR-8/SVneo) isolated by differential and buoyant density centrifugation. The effects of exo-EVT on VSMC migration were established using a real-time, live-cell imaging system (Incucyte™). Exosomal proteins where identified by mass spectrometry and submitted to bioinformatic pathway analysis (Ingenuity software). Results: HTR-8/SVneo cells were significantly more (~30%) invasive than JEG-3 cells. HTR-8/SVneo cells released 2.6-fold more exosomes (6.39 × 108 ± 2.5 × 108 particles/106 cells) compared to JEG-3 (2.86 × 108 ± 0.78 × 108 particles/106 cells). VSMC migration was significantly increased in the presence of exo-JEG-3 and exo-HTR-8/SVneo compared to control (−exosomes) (21.83 ± 0.49 h and 15.57 ± 0.32, respectively, vs. control 25.09 ± 0.58 h, p < 0.05). Sonication completely abolished the effect of exosomes on VSMC migration. Finally, mass spectrometry analysis identified unique exosomal proteins for each EVT cell line-derived exosomes. Conclusion: The data obtained in this study are consistent with the hypothesis that the release, content, and bioactivity of exosomes derived from EVT-like cell lines is cell origin-dependent and differentially regulates VSMC migration. Thus, an EVT exosomal signaling pathway may contribute to SpA remodeling by promoting the migration of VSMC out of the vessel walls. PMID:25157233

  17. Gold Nanoparticles Inhibit VEGF165-Induced Migration and Tube Formation of Endothelial Cells via the Akt Pathway

    PubMed Central

    Pan, Yunlong; Wu, Qing; Qin, Li; Cai, Jiye; Du, Bin

    2014-01-01

    The early stages of angiogenesis can be divided into three steps: endothelial cell proliferation, migration, and tube formation. Vascular endothelial growth factor (VEGF) is considered the most important proangiogenic factor; in particular, VEGF165 plays a critical role in angiogenesis. Here, we evaluated whether gold nanoparticles (AuNPs) could inhibit the VEGF165-induced human umbilical vein endothelial cell (HUVEC) migration and tube formation. AuNPs and VEGF165 were coincubated overnight at 4°C, after which the effects on cell migration and tube formation were assessed. Cell migration was assessed using a modified wound-healing assay and a transwell chamber assay; tube formation was assessed using a capillary-like tube formation assay and a chick chorioallantoic membrane (CAM) assay. We additionally detected the cell surface morphology and ultrastructure using atomic force microscopy (AFM). Furthermore, Akt phosphorylation downstream of VEGFR-2/PI3K in HUVECs was determined in a Western blot analysis. Our study demonstrated that AuNPs significantly inhibited VEGF165-induced HUVEC migration and tube formation by affecting the cell surface ultrastructure, cytoskeleton and might have inhibited angiogenesis via the Akt pathway. PMID:24987682

  18. Gold nanoparticles inhibit VEGF165-induced migration and tube formation of endothelial cells via the Akt pathway.

    PubMed

    Pan, Yunlong; Wu, Qing; Qin, Li; Cai, Jiye; Du, Bin

    2014-01-01

    The early stages of angiogenesis can be divided into three steps: endothelial cell proliferation, migration, and tube formation. Vascular endothelial growth factor (VEGF) is considered the most important proangiogenic factor; in particular, VEGF165 plays a critical role in angiogenesis. Here, we evaluated whether gold nanoparticles (AuNPs) could inhibit the VEGF165-induced human umbilical vein endothelial cell (HUVEC) migration and tube formation. AuNPs and VEGF165 were coincubated overnight at 4°C, after which the effects on cell migration and tube formation were assessed. Cell migration was assessed using a modified wound-healing assay and a transwell chamber assay; tube formation was assessed using a capillary-like tube formation assay and a chick chorioallantoic membrane (CAM) assay. We additionally detected the cell surface morphology and ultrastructure using atomic force microscopy (AFM). Furthermore, Akt phosphorylation downstream of VEGFR-2/PI3K in HUVECs was determined in a Western blot analysis. Our study demonstrated that AuNPs significantly inhibited VEGF165-induced HUVEC migration and tube formation by affecting the cell surface ultrastructure, cytoskeleton and might have inhibited angiogenesis via the Akt pathway. PMID:24987682

  19. Erianin inhibits the proliferation of T47D cells by inhibiting cell cycles, inducing apoptosis and suppressing migration.

    PubMed

    Sun, Jing; Fu, Xueqi; Wang, Yongsen; Liu, Ye; Zhang, Yu; Hao, Tian; Hu, Xin

    2016-01-01

    Erianin is a natural product extracted from Dendrobiumchrysotoxum. To investigate the antitumor activity of Erianin in estrogen receptor (ER) positive breast cancer, we treated T47D cells with Erianin and evaluated the effects of Erianin treatment on multiple cancer-associated pathways. Erianin inhibited the proliferation of T47D cells effectively. Erianin induced apoptosis in T47D cells through reducing Bcl-2 expression and activating caspase signaling. Furthermore, it also suppressed the expression of CDKs and caused cell cycle arrest. In addition, Erianin treatment suppressed the migration of T47D cells, most likely through regulating the homeostatic expression of MPP and TIMP. Meanwhile, Erianin did not affect the proliferation of normal breast epithelial cell line MCF10A. Together, these results demonstrated that Erianin might have the potential to be an effective drug to treat the ER positive breast cancer. PMID:27508028

  20. Erianin inhibits the proliferation of T47D cells by inhibiting cell cycles, inducing apoptosis and suppressing migration

    PubMed Central

    Sun, Jing; Fu, Xueqi; Wang, Yongsen; Liu, Ye; Zhang, Yu; Hao, Tian; Hu, Xin

    2016-01-01

    Erianin is a natural product extracted from Dendrobiumchrysotoxum. To investigate the antitumor activity of Erianin in estrogen receptor (ER) positive breast cancer, we treated T47D cells with Erianin and evaluated the effects of Erianin treatment on multiple cancer-associated pathways. Erianin inhibited the proliferation of T47D cells effectively. Erianin induced apoptosis in T47D cells through reducing Bcl-2 expression and activating caspase signaling. Furthermore, it also suppressed the expression of CDKs and caused cell cycle arrest. In addition, Erianin treatment suppressed the migration of T47D cells, most likely through regulating the homeostatic expression of MPP and TIMP. Meanwhile, Erianin did not affect the proliferation of normal breast epithelial cell line MCF10A. Together, these results demonstrated that Erianin might have the potential to be an effective drug to treat the ER positive breast cancer. PMID:27508028

  1. Cadherin-11 mediates contact inhibition of locomotion during Xenopus neural crest cell migration.

    PubMed

    Becker, Sarah F S; Mayor, Roberto; Kashef, Jubin

    2013-01-01

    Collective cell migration is an essential feature both in embryonic development and cancer progression. The molecular mechanisms of these coordinated directional cell movements still need to be elucidated. The migration of cranial neural crest (CNC) cells during embryogenesis is an excellent model for collective cell migration in vivo. These highly motile and multipotent cells migrate directionally on defined routes throughout the embryo. Interestingly, local cell-cell interactions seem to be the key force for directionality. CNC cells can change their migration direction by a repulsive cell response called contact inhibition of locomotion (CIL). Cell protrusions collapse upon homotypic cell-cell contact and internal repolarization leads to formation of new protrusions toward cell-free regions. Wnt/PCP signaling was shown to mediate activation of small RhoGTPase RhoA and inhibition of cell protrusions at the contact side. However, the mechanism how a cell recognizes the contact is poorly understood. Here, we demonstrate that Xenopus cadherin-11 (Xcad-11) mediated cell-cell adhesion is necessary in CIL for directional and collective migration of CNC cells. Reduction of Xcad-11 adhesive function resulted in higher invasiveness of CNC due to loss of CIL. Additionally, transplantation analyses revealed that CNC migratory behaviour in vivo is non-directional and incomplete when Xcad-11 adhesive function is impaired. Blocking Wnt/PCP signaling led to similar results underlining the importance of Xcad-11 in the mechanism of CIL and directional migration of CNC.

  2. The niche-derived glial cell line-derived neurotrophic factor (GDNF) induces migration of mouse spermatogonial stem/progenitor cells.

    PubMed

    Dovere, Lisa; Fera, Stefania; Grasso, Margherita; Lamberti, Dante; Gargioli, Cesare; Muciaccia, Barbara; Lustri, Anna Maria; Stefanini, Mario; Vicini, Elena

    2013-01-01

    In mammals, the biological activity of the stem/progenitor compartment sustains production of mature gametes through spermatogenesis. Spermatogonial stem cells and their progeny belong to the class of undifferentiated spermatogonia, a germ cell population found on the basal membrane of the seminiferous tubules. A large body of evidence has demonstrated that glial cell line-derived neurotrophic factor (GDNF), a Sertoli-derived factor, is essential for in vivo and in vitro stem cell self-renewal. However, the mechanisms underlying this activity are not completely understood. In this study, we show that GDNF induces dose-dependent directional migration of freshly selected undifferentiated spermatogonia, as well as germline stem cells in culture, using a Boyden chamber assay. GDNF-induced migration is dependent on the expression of the GDNF co-receptor GFRA1, as shown by migration assays performed on parental and GFRA1-transduced GC-1 spermatogonial cell lines. We found that the actin regulatory protein vasodilator-stimulated phosphoprotein (VASP) is specifically expressed in undifferentiated spermatogonia. VASP belongs to the ENA/VASP family of proteins implicated in actin-dependent processes, such as fibroblast migration, axon guidance, and cell adhesion. In intact seminiferous tubules and germline stem cell cultures, GDNF treatment up-regulates VASP in a dose-dependent fashion. These data identify a novel role for the niche-derived factor GDNF, and they suggest that GDNF may impinge on the stem/progenitor compartment, affecting the actin cytoskeleton and cell migration.

  3. Selective Migration of Subpopulations of Bone Marrow Cells along an SDF-1α and ATP Gradient

    PubMed Central

    Laupheimer, Michael; Skorska, Anna; Große, Jana; Tiedemann, Gudrun; Steinhoff, Gustav; David, Robert; Lux, Cornelia A.

    2014-01-01

    Both stem cell chemokine stromal cell-derived factor-1α (SDF-1α) and extracellular nucleotides such as adenosine triphosphate (ATP) are increased in ischemic myocardium. Since ATP has been reported to influence cell migration, we analysed the migratory response of bone marrow cells towards a combination of SDF-1 and ATP. Total nucleated cells (BM-TNCs) were isolated from bone marrow of cardiac surgery patients. Migration assays were performed in vitro. Subsequently, migrated cells were subjected to multicolor flow cytometric analysis of CD133, CD34, CD117, CD184, CD309, and CD14 expression. BM-TNCs migrated significantly towards a combination of SDF-1 and ATP. The proportions of CD34+ cells as well as subpopulations coexpressing multiple stem cell markers were selectively enhanced after migration towards SDF-1 or SDF-1 + ATP. After spontaneous migration, significantly fewer stem cells and CD184+ cells were detected. Direct incubation with SDF-1 led to a reduction of CD184+ but not stem cell marker-positive cells, while incubation with ATP significantly increased CD14+ percentage. In summary, we found that while a combination of SDF-1 and ATP elicited strong migration of BM-TNCs in vitro, only SDF-1 was responsible for selective attraction of hematopoietic stem cells. Meanwhile, spontaneous migration of stem cells was lower compared to BM-TNCs or monocytes. PMID:25610653

  4. Iodine Migration and its Effect on Hysteresis in Perovskite Solar Cells.

    PubMed

    Li, Cheng; Tscheuschner, Steffen; Paulus, Fabian; Hopkinson, Paul E; Kießling, Johannes; Köhler, Anna; Vaynzof, Yana; Huettner, Sven

    2016-03-23

    The migration and accumulation of iodide ions create a modulation of the respective interfacial barriers causing the hysteresis in solar cells based on methylammonium lead iodide perovskites. Iodide ions are identified as the migrating species by measuring temperature dependent current-transients and photoelectron spectroscopy. The involved changes in the built-in potential due to ion migration are directly measured by electroabsorption spectroscopy.

  5. Tick saliva regulates migration, phagocytosis, and gene expression in the macrophage-like cell line, IC-21.

    PubMed

    Kramer, Carolyn D; Poole, Nina M; Coons, Lewis B; Cole, Judith A

    2011-03-01

    We studied the effects of tick saliva on cell migration, cell signaling, phagocytosis, and gene expression in the murine macrophage cell line, IC-21. Saliva increased both basal- and platelet-derived growth factor (PDGF)-stimulated migration in IC-21 cells. However, saliva did not affect PDGF-stimulated extracellular signal-regulated kinase (ERK) activity. Zymosan-mediated interleukin-1 receptor associated kinase (IRAK) activity increased when cells were pretreated with saliva. Saliva suppressed phagocytosis of zymosan particles by IC-21 cells. An RT(2) Profiler™ PCR Array revealed that saliva regulates gene expression in a manner consistent with an immune response skewed toward a Th2 reaction, which is characterized by production of anti-inflammatory cytokines IL-4 and IL-10. Our results using IC-21 cells suggest that Dermacentor variabilis has evolved a mechanism for regulating macrophage function, which may contribute to the tick's ability to modulate immune function. PMID:21145320

  6. Spatial proteomic and phospho-proteomic organization in three prototypical cell migration modes

    PubMed Central

    2014-01-01

    Background Tight spatio-temporal signaling of cytoskeletal and adhesion dynamics is required for localized membrane protrusion that drives directed cell migration. Different ensembles of proteins are therefore likely to get recruited and phosphorylated in membrane protrusions in response to specific cues. Results Here, we use an assay that allows to biochemically purify extending protrusions of cells migrating in response to three prototypical receptors: integrins, recepor tyrosine kinases and G-coupled protein receptors. Using quantitative proteomics and phospho-proteomics approaches, we provide evidence for the existence of cue-specific, spatially distinct protein networks in the different cell migration modes. Conclusions The integrated analysis of the large-scale experimental data with protein information from databases allows us to understand some emergent properties of spatial regulation of signaling during cell migration. This provides the cell migration community with a large-scale view of the distribution of proteins and phospho-proteins regulating directed cell migration. PMID:24987309

  7. Polydatin induces bone marrow stromal cells migration by activation of ERK1/2.

    PubMed

    Chen, ZhenQiu; Wei, QiuShi; Hong, GuoJu; Chen, Da; Liang, Jiang; He, Wei; Chen, Mei Hui

    2016-08-01

    Bone marrow stromal cells (BMSCs) have proven to be useful for the treatment of numerous human diseases. However, the reparative ability of BMSCs is limited by their poor migration. Polydatin, widely used in traditional Chinese remedies, has proven to exert protective effects to BMSCs. However, little is known about its role in BMSCs migration. In this study, we studied the effects of polydatin on rat BMSCs migration using the scratch wound healing and transwell migration assays. Our results showed polydatin could promote BMSCs migration. Further experiments showed activation of ERK 1/2, but not JNK, was required for polydatin-induced BMSCs migration, suggesting that polydatin may promote BMSCs migration via the ERK 1/2 signaling pathways. Taken together, our results indicate that polydatin might be beneficial for stem cell replacement therapy by improving BMSCs migration.

  8. Contact inhibition of locomotion probabilities drive solitary versus collective cell migration

    PubMed Central

    Desai, Ravi A.; Gopal, Smitha B.; Chen, Sophia; Chen, Christopher S.

    2013-01-01

    Contact inhibition of locomotion (CIL) is the process whereby cells collide, cease migrating in the direction of the collision, and repolarize their migration machinery away from the collision. Quantitative analysis of CIL has remained elusive because cell-to-cell collisions are infrequent in traditional cell culture. Moreover, whereas CIL predicts mutual cell repulsion and ‘scattering’ of cells, the same cells in vivo are observed to undergo CIL at some developmental times and collective cell migration at others. It remains unclear whether CIL is simply absent during collective cell migration, or if the two processes coexist and are perhaps even related. Here, we used micropatterned stripes of extracellular matrix to restrict cell migration to linear paths such that cells polarized in one of two directions and collisions between cells occurred frequently and consistently, permitting quantitative and unbiased analysis of CIL. Observing repolarization events in different contexts, including head-to-head collision, head-to-tail collision, collision with an inert barrier, or no collision, and describing polarization as a two-state transition indicated that CIL occurs probabilistically, and most strongly upon head-to-head collisions. In addition to strong CIL, we also observed ‘trains’ of cells moving collectively with high persistence that appeared to emerge from single cells. To reconcile these seemingly conflicting observations of CIL and collective cell migration, we constructed an agent-based model to simulate our experiments. Our model quantitatively predicted the emergence of collective migration, and demonstrated the sensitivity of such emergence to the probability of CIL. Thus CIL and collective migration can coexist, and in fact a shift in CIL probabilities may underlie transitions between solitary cell migration and collective cell migration. Taken together, our data demonstrate the emergence of persistently polarized, collective cell movement

  9. Mammary collective cell migration involves transient loss of epithelial features and individual cell migration within the epithelium

    PubMed Central

    Ewald, Andrew J.; Huebner, Robert J.; Palsdottir, Hildur; Lee, Jessie K.; Perez, Melissa J.; Jorgens, Danielle M.; Tauscher, Andrew N.; Cheung, Kevin J.; Werb, Zena; Auer, Manfred

    2012-01-01

    Normal mammary morphogenesis involves transitions between simple and multilayered epithelial organizations. We used electron microscopy and molecular markers to determine whether intercellular junctions and apico-basal polarity were maintained in the multilayered epithelium. We found that multilayered elongating ducts had polarized apical and basal tissue surfaces both in three-dimensional culture and in vivo. However, individual cells were only polarized on surfaces in contact with the lumen or extracellular matrix. The basolateral marker scribble and the apical marker atypical protein kinase C zeta localized to all interior cell membranes, whereas PAR3 displayed a cytoplasmic localization, suggesting that the apico-basal polarity was incomplete. Despite membrane localization of E-cadherin and β-catenin, we did not observe a defined zonula adherens connecting interior cells. Instead, interior cells were connected through desmosomes and exhibited complex interdigitating membrane protrusions. Single-cell labeling revealed that individual cells were both protrusive and migratory within the epithelial multilayer. Inhibition of Rho kinase (ROCK) further reduced intercellular adhesion on apical and lateral surfaces but did not disrupt basal tissue organization. Following morphogenesis, segregated membrane domains were re-established and junctional complexes re-formed. We observed similar epithelial organization during mammary morphogenesis in organotypic culture and in vivo. We conclude that mammary epithelial morphogenesis involves a reversible, spatially limited, reduction in polarity and intercellular junctions and active individualistic cell migration. Our data suggest that reductions in polarity and adhesion during breast cancer progression might reflect partial recapitulation of a normal developmental program. PMID:22344263

  10. Adhesion, Proliferation and Migration of NIH/3T3 Cells on Modified Polyaniline Surfaces

    PubMed Central

    Rejmontová, Petra; Capáková, Zdenka; Mikušová, Nikola; Maráková, Nela; Kašpárková, Věra; Lehocký, Marián; Humpolíček, Petr

    2016-01-01

    Polyaniline shows great potential and promises wide application in the biomedical field thanks to its intrinsic conductivity and material properties, which closely resemble natural tissues. Surface properties are crucial, as these predetermine any interaction with biological fluids, proteins and cells. An advantage of polyaniline is the simple modification of its surface, e.g., by using various dopant acids. An investigation was made into the adhesion, proliferation and migration of mouse embryonic fibroblasts on pristine polyaniline films and films doped with sulfamic and phosphotungstic acids. In addition, polyaniline films supplemented with poly (2-acrylamido-2-methyl-1-propanesulfonic) acid at various ratios were tested. Results showed that the NIH/3T3 cell line was able to adhere, proliferate and migrate on the pristine polyaniline films as well as those films doped with sulfamic and phosphotungstic acids; thus, utilization of said forms in biomedicine appears promising. Nevertheless, incorporating poly (2-acrylamido-2-methyl-1-propanesulfonic) acid altered the surface properties of the polyaniline films and significantly affected cell behavior. In order to reveal the crucial factor influencing the surface/cell interaction, cell behavior is discussed in the context of the surface energy of individual samples. It was clearly demonstrated that the lesser the difference between the surface energy of the sample and cell, the more cyto-compatible the surface is. PMID:27649159

  11. Adhesion, Proliferation and Migration of NIH/3T3 Cells on Modified Polyaniline Surfaces.

    PubMed

    Rejmontová, Petra; Capáková, Zdenka; Mikušová, Nikola; Maráková, Nela; Kašpárková, Věra; Lehocký, Marián; Humpolíček, Petr

    2016-01-01

    Polyaniline shows great potential and promises wide application in the biomedical field thanks to its intrinsic conductivity and material properties, which closely resemble natural tissues. Surface properties are crucial, as these predetermine any interaction with biological fluids, proteins and cells. An advantage of polyaniline is the simple modification of its surface, e.g., by using various dopant acids. An investigation was made into the adhesion, proliferation and migration of mouse embryonic fibroblasts on pristine polyaniline films and films doped with sulfamic and phosphotungstic acids. In addition, polyaniline films supplemented with poly (2-acrylamido-2-methyl-1-propanesulfonic) acid at various ratios were tested. Results showed that the NIH/3T3 cell line was able to adhere, proliferate and migrate on the pristine polyaniline films as well as those films doped with sulfamic and phosphotungstic acids; thus, utilization of said forms in biomedicine appears promising. Nevertheless, incorporating poly (2-acrylamido-2-methyl-1-propanesulfonic) acid altered the surface properties of the polyaniline films and significantly affected cell behavior. In order to reveal the crucial factor influencing the surface/cell interaction, cell behavior is discussed in the context of the surface energy of individual samples. It was clearly demonstrated that the lesser the difference between the surface energy of the sample and cell, the more cyto-compatible the surface is. PMID:27649159

  12. Nuclear Lamin A/C Deficiency Induces Defects in Cell Mechanics, Polarization, and Migration

    PubMed Central

    Lee, Jerry S. H.; Hale, Christopher M.; Panorchan, Porntula; Khatau, Shyam B.; George, Jerry P.; Tseng, Yiider; Stewart, Colin L.; Hodzic, Didier; Wirtz, Denis

    2007-01-01

    Lamin A/C is a major constituent of the nuclear lamina, a thin filamentous protein layer that lies beneath the nuclear envelope. Here we show that lamin A/C deficiency in mouse embryonic fibroblasts (Lmna−/− MEFs) diminishes the ability of these cells to polarize at the edge of a wound and significantly reduces cell migration speed into the wound. Moreover, lamin A/C deficiency induces significant separation of the microtubule organizing center (MTOC) from the nuclear envelope. Investigations using ballistic intracellular nanorheology reveal that lamin A/C deficiency also dramatically affects the micromechanical properties of the cytoplasm. Both the elasticity (stretchiness) and the viscosity (propensity of a material to flow) of the cytoplasm in Lmna−/− MEFs are significantly reduced. Disassembly of either the actin filament or microtubule networks in Lmna+/+ MEFs results in decrease of cytoplasmic elasticity and viscosity down to levels found in Lmna−/− MEFs. Together these results show that both the mechanical properties of the cytoskeleton and cytoskeleton-based processes, including cell motility, coupled MTOC and nucleus dynamics, and cell polarization, depend critically on the integrity of the nuclear lamina, which suggest the existence of a functional mechanical connection between the nucleus and the cytoskeleton. These results also suggest that cell polarization during cell migration requires tight mechanical coupling between MTOC and nucleus, which is mediated by lamin A/C. PMID:17631533

  13. Extracellular Mipp1 Activity Confers Migratory Advantage to Epithelial Cells during Collective Migration.

    PubMed

    Cheng, Yim Ling; Andrew, Deborah J

    2015-12-15

    Multiple inositol polyphosphate phosphatase (Mipp), a highly conserved but poorly understood histidine phosphatase, dephosphorylates higher-order IPs (IP4-IP6) to IP3. To gain insight into the biological roles of these enzymes, we have characterized Drosophila mipp1. mipp1 is dynamically expressed in the embryonic trachea, specifically in the leading cells of migrating branches at late stages, where Mipp1 localizes to the plasma membrane and filopodia. FGF signaling activates mipp1 expression in these cells, where extensive filopodia form to drive migration and elongation by cell intercalation. We show that Mipp1 facilitates formation and/or stabilization of filopodia in leading cells through its extracellular activity. mipp1 loss decreases filopodia number, whereas mipp1 overexpression increases filopodia number in a phosphatase-activity-dependent manner. Importantly, expression of Mipp1 gives cells a migratory advantage for the lead position in elongating tracheal branches. Altogether, these findings suggest that extracellular pools of inositol polyphosphates affect cell behavior during development.

  14. Adhesion, Proliferation and Migration of NIH/3T3 Cells on Modified Polyaniline Surfaces.

    PubMed

    Rejmontová, Petra; Capáková, Zdenka; Mikušová, Nikola; Maráková, Nela; Kašpárková, Věra; Lehocký, Marián; Humpolíček, Petr

    2016-09-15

    Polyaniline shows great potential and promises wide application in the biomedical field thanks to its intrinsic conductivity and material properties, which closely resemble natural tissues. Surface properties are crucial, as these predetermine any interaction with biological fluids, proteins and cells. An advantage of polyaniline is the simple modification of its surface, e.g., by using various dopant acids. An investigation was made into the adhesion, proliferation and migration of mouse embryonic fibroblasts on pristine polyaniline films and films doped with sulfamic and phosphotungstic acids. In addition, polyaniline films supplemented with poly (2-acrylamido-2-methyl-1-propanesulfonic) acid at various ratios were tested. Results showed that the NIH/3T3 cell line was able to adhere, proliferate and migrate on the pristine polyaniline films as well as those films doped with sulfamic and phosphotungstic acids; thus, utilization of said forms in biomedicine appears promising. Nevertheless, incorporating poly (2-acrylamido-2-methyl-1-propanesulfonic) acid altered the surface properties of the polyaniline films and significantly affected cell behavior. In order to reveal the crucial factor influencing the surface/cell interaction, cell behavior is discussed in the context of the surface energy of individual samples. It was clearly demonstrated that the lesser the difference between the surface energy of the sample and cell, the more cyto-compatible the surface is.

  15. Migration of tumor cells in 3D matrices is governed by matrix stiffness along with cell-matrix adhesion and proteolysis

    NASA Astrophysics Data System (ADS)

    Zaman, Muhammad H.; Trapani, Linda M.; Sieminski, Alisha L.; MacKellar, Drew; Gong, Haiyan; Kamm, Roger D.; Wells, Alan; Lauffenburger, Douglas A.; Matsudaira, Paul

    2006-07-01

    Cell migration on 2D surfaces is governed by a balance between counteracting tractile and adhesion forces. Although biochemical factors such as adhesion receptor and ligand concentration and binding, signaling through cell adhesion complexes, and cytoskeletal structure assembly/disassembly have been studied in detail in a 2D context, the critical biochemical and biophysical parameters that affect cell migration in 3D matrices have not been quantitatively investigated. We demonstrate that, in addition to adhesion and tractile forces, matrix stiffness is a key factor that influences cell movement in 3D. Cell migration assays in which Matrigel density, fibronectin concentration, and 1 integrin binding are systematically varied show that at a specific Matrigel density the migration speed of DU-145 human prostate carcinoma cells is a balance between tractile and adhesion forces. However, when biochemical parameters such as matrix ligand and cell integrin receptor levels are held constant, maximal cell movement shifts to matrices exhibiting lesser stiffness. This behavior contradicts current 2D models but is predicted by a recent force-based computational model of cell movement in a 3D matrix. As expected, this 3D motility through an extracellular environment of pore size much smaller than cellular dimensions does depend on proteolytic activity as broad-spectrum matrix metalloproteinase (MMP) inhibitors limit the migration of DU-145 cells and also HT-1080 fibrosarcoma cells. Our experimental findings here represent, to our knowledge, discovery of a previously undescribed set of balances of cell and matrix properties that govern the ability of tumor cells to migration in 3D environments. cell motility | EGF receptor | extracellular matrix | matrix metalloproteinase

  16. miR-1 Inhibits Cell Growth, Migration, and Invasion by Targeting VEGFA in Osteosarcoma Cells

    PubMed Central

    Niu, Junjie; Guo, Qiaoge; Niu, Dongju; Liu, Bo

    2016-01-01

    microRNAs (miRNAs) are small noncoding RNAs and have been shown to play a crucial role in the osteosarcoma (OS) tumorigenesis and progression. VEGFA is a key regulator of angiogenesis and plays an important role in regulation of tumor metastasis. The objective of this study was to determine whether VEGFA was involved in miR-1-mediated suppression of proliferation, migration, and invasion of OS cells. The expression levels of miR-1 were significantly lower in OS tumor tissues than those in adjacent normal tissues and in SAOS-2 and U2OS cell lines compared to a normal osteoblast (NHOst) cell line. VEGFA was upregulated in OS tumor tissues and SAOS-2 and U2OS cell lines. The results of CCK-8 assay and transwell assay showed that miR-1 acted as a tumor suppressor by inhibiting cell proliferation, migration, and invasion in U2OS cells. Dual luciferase reporter assay demonstrated that VEGFA was a direct and functional target gene of miR-1. miR-1 directly inhibits the protein expression of VEGFA via its 3′-UTR. Knockdown of VEGFA by siRNA inhibited proliferation, migration, and invasion of U2OS cells. Our study suggested the potential inhibitory function of miR-1 in OS cell proliferation, migration, and invasion via inhibiting VEGFA. PMID:27777493

  17. A Macroscopic Mathematical Model for Cell Migration Assays Using a Real-Time Cell Analysis

    PubMed Central

    Angelini, Claudia; Carfora, Maria Francesca; Carriero, Maria Vincenza; Natalini, Roberto

    2016-01-01

    Experiments of cell migration and chemotaxis assays have been classically performed in the so-called Boyden Chambers. A recent technology, xCELLigence Real Time Cell Analysis, is now allowing to monitor the cell migration in real time. This technology measures impedance changes caused by the gradual increase of electrode surface occupation by cells during the course of time and provide a Cell Index which is proportional to cellular morphology, spreading, ruffling and adhesion quality as well as cell number. In this paper we propose a macroscopic mathematical model, based on advection-reaction-diffusion partial differential equations, describing the cell migration assay using the real-time technology. We carried out numerical simulations to compare simulated model dynamics with data of observed biological experiments on three different cell lines and in two experimental settings: absence of chemotactic signals (basal migration) and presence of a chemoattractant. Overall we conclude that our minimal mathematical model is able to describe the phenomenon in the real time scale and numerical results show a good agreement with the experimental evidences. PMID:27680883

  18. Expression of WNT genes in cervical cancer-derived cells: Implication of WNT7A in cell proliferation and migration

    SciTech Connect

    Ramos-Solano, Moisés; Meza-Canales, Ivan D.; Torres-Reyes, Luis A.; Alvarez-Zavala, Monserrat; and others

    2015-07-01

    According to the multifactorial model of cervical cancer (CC) causation, it is now recognized that other modifications, in addition to Human papillomavirus (HPV) infection, are necessary for the development of this neoplasia. Among these, it has been proposed that a dysregulation of the WNT pathway might favor malignant progression of HPV-immortalized keratinocytes. The aim of this study was to identify components of the WNT pathway differentially expressed in CC vs. non-tumorigenic, but immortalized human keratinocytes. Interestingly, WNT7A expression was found strongly downregulated in cell lines and biopsies derived from CC. Restoration of WNT7A in CC-derived cell lines using a lentiviral gene delivery system or after adding a recombinant human protein decreases cell proliferation. Likewise, WNT7A silencing in non-tumorigenic cells markedly accelerates proliferation. Decreased WNT7A expression was due to hypermethylation at particular CpG sites. To our knowledge, this is the first study reporting reduced WNT7A levels in CC-derived cells and that ectopic WNT7A restoration negatively affects cell proliferation and migration. - Highlights: • WNT7A is expressed in normal keratinocytes or cervical cells without lesion. • WNT7A is significantly reduced in cervical cancer-derived cells. • Restoration of WNT7A expression in HeLa decreases proliferation and cell migration. • Silencing of WNT7A in HaCaT induces an increased proliferation and migration rate. • Decreased WNT7A expression in this model is due to hypermethylation.

  19. Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

    USGS Publications Warehouse

    Hooijmeijer, Jos C. E. W.; Gill, Robert E.; Mulcahy, Daniel M.; Tibbitts, T. Lee; Kentie, Rosemarie; Gerritsen, Gerrit J.; Bruinzeel, Leo W.; Tijssen, David C.; Harwood, Christopher M.; Piersma, Theunis

    2014-01-01

    Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds

  20. Does the Phaeocystis bloom affect the diel migration of the suprabenthos community?

    PubMed

    Dauvin, Jean-Claude; Desroy, Nicolas; Denis, Lionel; Ruellet, Thierry

    2008-01-01

    The suprabenthos comprises all bottom-dependent animals, mainly crustaceans (including decapods and peracarids), which perform--with varying amplitude, intensity and regularity--seasonal or daily vertical migrations above the sea floor. The presence of organisms in the Benthic Boundary Layer is determined by two general factors: (1) organism behaviour, which depends on the light penetration in the water column and (2) boundary-layer hydrodynamics. In the coastal zone of the eastern English Channel, during the spring Phaeocystis bloom, the presence of gelatinous colonies modifies the penetration of light in the water column, which may seriously affect the abundance and/or the behaviour of the suprabenthos community. To clarify this point, 19 suprabenthic hauls were taken with a modified Macer-GIROQ sledge both during the day and during the night, from March to June 2002 (i.e., before, during and after the bloom). Two sites, located in the coastal and offshore areas of the Ophelia medium sand macrobenthic community were investigated. The bloom had no effect on species richness and abundance in either site. However, the diel migrations of some dominant species--such as the cumaceans Pseudocuma longicornis and Pseudocuma similis, the mysid Gastrosaccus spinifer and the amphipod Stenothoe marina--were modified. During the bloom, diurnal and nocturnal suprabenthic abundances were similar, and in the absence of bloom, species remained benthic during the day. The permanent presence of suprabenthic species in the Benthic Boundary Layer could have a consequence on their predation by fish (mainly juveniles which preferentially consume small crustaceans in their diet), unless fish behaviour and predation efficiency--especially for visual predators--are also disturbed by changes in light intensity.

  1. Intestinal epithelial cell proliferation and migration in Atlantic salmon, Salmo salar L.: effects of temperature and inflammation.

    PubMed

    Chikwati, Elvis M; Gu, Jinni; Penn, Michael H; Bakke, Anne Marie; Krogdahl, Ashild

    2013-07-01

    A 28-day feeding trial was carried out to characterise intestinal epithelial cell (IEC) turnover in Atlantic salmon (Salmo salar L.) post-smolts in seawater. Four groups of fish raised at two temperatures of 8°C or 12°C and fed two different diets were investigated. The diets included a reference maize gluten and fishmeal-based diet (FM) and an experimental enteropathy-causing diet containing 20% extracted soybean meal (SBM). IEC proliferation and migration were investigated by labelling cells with the in vivo proliferation marker 5-bromo-2'-deoxyuridine (BrdU). Proliferating cell nuclear antigen (PCNA) labelling was used as a control for identifying proliferating cells. Samples of the proximal (PI), mid (MI) and distal (DI) intestinal regions were collected at five time points (3 h-28 days) over the experimental period. Histologically, FM-fed fish had normal mucosa, whereas the SBM-fed fish developed DI enteropathy. Major zones of cell proliferation were observed in the mucosal fold bases for all intestinal regions. Over time, BrdU-labelled cells migrated up mucosal folds to the tips before being lost. Migration rates were dependent on intestinal region, temperature and diet. Highest migration rates were observed in the PI followed by the MI and DI for FM-fed fish. Diet and temperature barely affected migration in the PI and MI. Migration in the DI was most sensitive to diet and temperature, with both SBM and the higher water temperature increasing proliferation and migration rates. The slow IEC turnover in the DI might help to explain the sensitivity of this region to dietary SBM-induced enteropathy.

  2. Liprin-α1, ERC1 and LL5 define polarized and dynamic structures that are implicated in cell migration.

    PubMed

    Astro, Veronica; Chiaretti, Sara; Magistrati, Elisa; Fivaz, Marc; de Curtis, Ivan

    2014-09-01

    Cell migration during development and metastatic invasion requires the coordination of actin and adhesion dynamics to promote protrusive activity at the front of the cell. The knowledge of the molecular mechanisms required to achieve such coordination is fragmentary. Here, we identify a new functional complex that drives cell motility. ERC1a (an isoform of ERC1) and the LL5 proteins LL5α and LL5β (encoded by PHLDB1 and PHLDB2, respectively) are required, together with liprin-α1, for effective migration and tumor cell invasion, and do so by stabilizing the protrusive activity at the cell front. Depletion of either protein negatively affects invasion, migration on extracellular matrix, lamellipodial persistence and the internalization of active integrin β1 receptors needed for adhesion turnover at the front of the cell. Liprin-α1, ERC1a and LL5 also define new highly polarized and dynamic cytoplasmic structures uniquely localized near the protruding cell edge. Our results indicate that the functional complex and the associated structures described here represent an important mechanism to drive tumor cell migration.

  3. Lumican induces human corneal epithelial cell migration and integrin expression via ERK 1/2 signaling

    SciTech Connect

    Seomun, Young; Joo, Choun-Ki

    2008-07-18

    Lumican is a major proteoglycans of the human cornea. Lumican knock-out mice have been shown to lose corneal transparency and to display delayed wound healing. The purpose of this study was to define the role of lumican in corneal epithelial cell migration. Over-expression of lumican in human corneal epithelial (HCE-T) cells increased both cell migration and proliferation, and increased levels of integrins {alpha}2 and {beta}1. ERK 1/2 was also activated in lumican over-expressed cells. When we treated HCE-T cells with the ERK-specific inhibitor U0126, cell migration and the expression of integrin {beta}1 were completely blocked. These data provide evidence that lumican stimulates cell migration in the corneal epithelium by activating ERK 1/2, and point to a novel signaling pathway implicated in corneal epithelial cell migration.

  4. Analysis of Cell Migration within a Three-dimensional Collagen Matrix

    PubMed Central

    Rommerswinkel, Nadine; Niggemann, Bernd; Keil, Silvia; Zänker, Kurt S.; Dittmar, Thomas

    2014-01-01

    The ability to migrate is a hallmark of various cell types and plays a crucial role in several physiological processes, including embryonic development, wound healing, and immune responses. However, cell migration is also a key mechanism in cancer enabling these cancer cells to detach from the primary tumor to start metastatic spreading. Within the past years various cell migration assays have been developed to analyze the migratory behavior of different cell types. Because the locomotory behavior of cells markedly differs between a two-dimensional (2D) and three-dimensional (3D) environment it can be assumed that the analysis of the migration of cells that are embedded within a 3D environment would yield in more significant cell migration data. The advantage of the described 3D collagen matrix migration assay is that cells are embedded within a physiological 3D network of collagen fibers representing the major component of the extracellular matrix. Due to time-lapse video microscopy real cell migration is measured allowing the determination of several migration parameters as well as their alterations in response to pro-migratory factors or inhibitors. Various cell types could be analyzed using this technique, including lymphocytes/leukocytes, stem cells, and tumor cells. Likewise, also cell clusters or spheroids could be embedded within the collagen matrix concomitant with analysis of the emigration of single cells from the cell cluster/ spheroid into the collagen lattice. We conclude that the 3D collagen matrix migration assay is a versatile method to analyze the migration of cells within a physiological-like 3D environment. PMID:25350138

  5. Analysis of cell migration within a three-dimensional collagen matrix.

    PubMed

    Rommerswinkel, Nadine; Niggemann, Bernd; Keil, Silvia; Zänker, Kurt S; Dittmar, Thomas

    2014-10-05

    The ability to migrate is a hallmark of various cell types and plays a crucial role in several physiological processes, including embryonic development, wound healing, and immune responses. However, cell migration is also a key mechanism in cancer enabling these cancer cells to detach from the primary tumor to start metastatic spreading. Within the past years various cell migration assays have been developed to analyze the migratory behavior of different cell types. Because the locomotory behavior of cells markedly differs between a two-dimensional (2D) and three-dimensional (3D) environment it can be assumed that the analysis of the migration of cells that are embedded within a 3D environment would yield in more significant cell migration data. The advantage of the described 3D collagen matrix migration assay is that cells are embedded within a physiological 3D network of collagen fibers representing the major component of the extracellular matrix. Due to time-lapse video microscopy real cell migration is measured allowing the determination of several migration parameters as well as their alterations in response to pro-migratory factors or inhibitors. Various cell types could be analyzed using this technique, including lymphocytes/leukocytes, stem cells, and tumor cells. Likewise, also cell clusters or spheroids could be embedded within the collagen matrix concomitant with analysis of the emigration of single cells from the cell cluster/ spheroid into the collagen lattice. We conclude that the 3D collagen matrix migration assay is a versatile method to analyze the migration of cells within a physiological-like 3D environment.

  6. Loss of lysophosphatidic acid receptor-3 enhances cell migration in rat lung tumor cells

    SciTech Connect

    Hayashi, Mai; Okabe, Kyoko; Yamawaki, Yasuna; Teranishi, Miki; Honoki, Kanya; Mori, Toshio; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2011-02-18

    Research highlights: {yields} Loss of the Lpar3 expression due to aberrant DNA methylation occurred in rat lung tumor cells. {yields} The Lpar3 inhibited cell migration of rat lung tumor cells. {yields} The Lpar3 may act as a negative regulator of rat lung tumor cells. -- Abstract: Lysophosphatidic acid (LPA) indicates several biological effects, such as cell proliferation, differentiation and migration. LPA interacts with G protein-coupled transmembrane LPA receptors. In our previous report, we detected that loss of the LPA receptor-1 (Lpar1) expression is due to its aberrant DNA methylation in rat tumor cell lines. In this study, to assess an involvement of the other LPA receptor, Lpar3, in the pathogenesis of rat lung tumor cells, we measured the expression levels of the Lpar3 gene and its DNA methylation status by reverse transcription (RT)-polymerase chain reaction (PCR) and bisulfite sequencing analyses, respectively. RLCNR lung adenocarcinoma cells showed reduced expression of the Lpar3, compared with normal lung tissues. In the 5' upstream region of the Lpar3, normal lung tissues were unmethylated. By contrast, RLCNR cells were highly methylated, correlating with reduced expressions of the Lpar3. Based on these results, we generated the Lpar3-expressing RLCNR-a3 cells and measured the cell migration ability. Interestingly, the cell migration of RLCNR-a3 cells was significantly lower than that of RLCNR cells. This study suggests that loss of the Lpar3 due to aberrant DNA methylation may be involved in the progression of rat lung tumor cells.

  7. Manipulation of neutrophil-like HL-60 cells for the study of directed cell migration.

    PubMed

    Millius, Arthur; Weiner, Orion D

    2010-01-01

    Many cells undergo directed cell migration in response to external cues in a process known as chemotaxis. This ability is essential for many single-celled organisms to hunt and mate, the development of multicellular organisms, and the functioning of the immune system. Because of their relative ease of manipulation and their robust chemotactic abilities, the neutrophil-like cell line (HL-60) has been a powerful system to analyze directed cell migration. In this chapter, we describe the maintenance and transient transfection of HL-60 cells and explain how to analyze their behavior with two standard chemotactic assays (micropipette and EZ-TAXIS). Finally, we demonstrate how to fix and stain the actin cytoskeleton of polarized cells for fluorescent microscopy imaging.

  8. Migration of tumor cells in 3D matrices is governed by matrix stiffness along with cell-matrix adhesion and proteolysis

    PubMed Central

    Zaman, Muhammad H.; Trapani, Linda M.; Sieminski, Alisha; MacKellar, Drew; Gong, Haiyan; Kamm, Roger D.; Wells, Alan; Lauffenburger, Douglas A.; Matsudaira, Paul

    2006-01-01

    Cell migration on 2D surfaces is governed by a balance between counteracting tractile and adhesion forces. Although biochemical factors such as adhesion receptor and ligand concentration and binding, signaling through cell adhesion complexes, and cytoskeletal structure assembly/disassembly have been studied in detail in a 2D context, the critical biochemical and biophysical parameters that affect cell migration in 3D matrices have not been quantitatively investigated. We demonstrate that, in addition to adhesion and tractile forces, matrix stiffness is a key factor that influences cell movement in 3D. Cell migration assays in which Matrigel density, fibronectin concentration, and β1 integrin binding are systematically varied show that at a specific Matrigel density the migration speed of DU-145 human prostate carcinoma cells is a balance between tractile and adhesion forces. However, when biochemical parameters such as matrix ligand and cell integrin receptor levels are held constant, maximal cell movement shifts to matrices exhibiting lesser stiffness. This behavior contradicts current 2D models but is predicted by a recent force-based computational model of cell movement in a 3D matrix. As expected, this 3D motility through an extracellular environment of pore size much smaller than cellular dimensions does depend on proteolytic activity as broad-spectrum matrix metalloproteinase (MMP) inhibitors limit the migration of DU-145 cells and also HT-1080 fibrosarcoma cells. Our experimental findings here represent, to our knowledge, discovery of a previously undescribed set of balances of cell and matrix properties that govern the ability of tumor cells to migration in 3D environments. PMID:16832052

  9. Integrin-mediated cell migration is blocked by inhibitors of human neuraminidase.

    PubMed

    Jia, Feng; Howlader, Md Amran; Cairo, Christopher W

    2016-09-01

    Integrins are critical receptors in cell migration and adhesion. A number of mechanisms are known to regulate the function of integrins, including phosphorylation, conformational change, and cytoskeletal anchoring. We investigated whether native neuraminidase (Neu, or sialidase) enzymes which modify glycolipids could play a role in regulating integrin-mediated cell migration. Using a scratch assay, we found that exogenously added Neu3 and Neu4 activity altered rates of cell migration. We observed that Neu4 increased the rate of migration in two cell lines (HeLa, A549); while Neu3 only increased migration in HeLa cells. A bacterial neuraminidase was able to increase the rate of migration in HeLa, but not in A549 cells. Treatment of cells with complex gangliosides (GM1, GD1a, GD1b, and GT1b) resulted in decreased cell migration rates, while LacCer was able to increase rates of migration in both lines. Importantly, our results show that treatment of cells with inhibitors of native Neu enzymes had a dramatic effect on the rates of cell migration. The most potent compound tested targeted the human Neu4 isoenzyme, and was able to substantially reduce the rate of cell migration. We found that the lateral mobility of integrins was reduced by treatment of cells with Neu3, suggesting that Neu3 enzyme activity resulted in changes to integrin-co-receptor or integrin-cytoskeleton interactions. Finally, our results support the hypothesis that inhibitors of human Neu can be used to investigate mechanisms of cell migration and for the development of anti-adhesive therapies.

  10. Mechanical Properties of Chicken Embryo Somites to Analyze Cell Migration during Somitegenesis

    NASA Astrophysics Data System (ADS)

    Zhukovsky, Sarit; Taneyhill, Lisa; Wu, Chyong; Aranda-Espinoza, Helim

    2013-03-01

    Somites develop as round segments on the sides of the neural tube and are responsible for the development of the vertebrae and other structures. Using Atomic Force Microscopy and Micropipette techniques, we were able to apply a known force to obtain data about the differences in the mechanical properties of the somites. Using contact mode in AFM, we obtained graphs that relate distance travelled by the cantilever versus deflection of the sample. We then used Matlab to analyze the data and find the material properties of the somites. We measured the Young's modulus of the anterior and posterior parts of the somites to be around 2 +/- 0.8 kPa, but further data is needed to finalize our conclusion. Finding the mechanical properties of the posterior and anterior parts of the somites helped us to mimic those mechanical properties on polyacrylamide gels with different stiffness to determine the physiological functions of the somites and predict any mechanical abnormalities that might affect the migration of stem cells. By observing the major steps of migration, we were able to better understand how cell migration orchestrates embryonic morphogenesis with respect to their known mechanical properties.

  11. Cadherin-2 Is Required Cell Autonomously for Collective Migration of Facial Branchiomotor Neurons

    PubMed Central

    Rebman, Jane K.; Kirchoff, Kathryn E.

    2016-01-01

    Collective migration depends on cell-cell interactions between neighbors that contribute to their overall directionality, yet the mechanisms that control the coordinated migration of neurons remains to be elucidated. During hindbrain development, facial branchiomotor neurons (FBMNs) undergo a stereotypic tangential caudal migration from their place of birth in rhombomere (r)4 to their final location in r6/7. FBMNs engage in collective cell migration that depends on neuron-to-neuron interactions to facilitate caudal directionality. Here, we demonstrate that Cadherin-2-mediated neuron-to-neuron adhesion is necessary for directional and collective migration of FBMNs. We generated stable transgenic zebrafish expressing dominant-negative Cadherin-2 (Cdh2ΔEC) driven by the islet1 promoter. Cell-autonomous inactivation of Cadherin-2 function led to non-directional migration of FBMNs and a defect in caudal tangential migration. Additionally, mosaic analysis revealed that Cdh2ΔEC-expressing FBMNs are not influenced to migrate caudally by neighboring wild-type FBMNs due to a defect in collective cell migration. Taken together, our data suggest that Cadherin-2 plays an essential cell-autonomous role in mediating the collective migration of FBMNs. PMID:27716840

  12. Toll-Like Receptors on Human Mesenchymal Stem Cells Drive their Migration and Immunomodulating Responses

    PubMed Central

    Tomchuck, Suzanne L.; Zwezdaryk, Kevin J.; Coffelt, Seth B.; Waterman, Ruth S.; Danka, Elizabeth S.; Scandurro, Aline B.

    2009-01-01

    Adult human bone marrow-derived mesenchymal stem cells (hMSCs) are under study as therapeutic delivery agents that assist in the repair of damaged tissues. To achieve the desired clinical outcomes for this strategy requires a better understanding of the mechanisms that drive the recruitment, migration and engraftment of hMSCs to the targeted tissues. It is known that hMSCs are recruited to sites of stress or inflammation to fulfill their repair function. It is recognized that toll-like receptors (TLRs) mediate stress responses of other bone marrow-derived cells. This study explored the role of TLRs in mediating stress responses of hMSCs. Accordingly, the presence of TLRs in hMSCs was established initially by RT-PCR assays. Flow cytometry and fluorescence immunocytochemical analyses confirmed these findings. The stimulation of hMSCs with TLR agonists led to the activation of downstream signaling pathways, including NF-κB, AKT and MAPK. Consequently, activation of these pathways triggered the induction and secretion of cytokines, chemokines and related TLR gene products as established from cDNA array, immunoassay and cytokine antibody array analyses. Interestingly, the unique patterns of affected genes, cytokines and chemokines measured, identify these receptors as critical players in the clinically established immunomodulation, observed for hMSCs. Lastly, hMSCs migration was promoted by TLR ligand exposure as demonstrated by transwell migration assays. Conversely, disruption of TLRs by neutralizing TLR antibodies compromised hMSCs migration. This study defines a novel TLR-driven stress and immune modulating response for hMSCs that is critical to consider in the design of stem cell-based therapies. PMID:17916800

  13. Insulin-producing cells from embryonic stem cells rescues hyperglycemia via intra-spleen migration.

    PubMed

    Ren, Meng; Shang, Changzhen; Zhong, Xiaomei; Guo, Ruomi; Lao, Guojuan; Wang, Xiaoyi; Cheng, Hua; Min, Jun; Yan, Li; Shen, Jun

    2014-12-23

    Implantation of embryonic stem cells (ESC)-derived insulin-producing cells has been extensively investigated for treatment of diabetes in animal models. However, the in vivo behavior and migration of transplanted cells in diabetic models remains unclear. Here we investigated the location and migration of insulin-producing cells labeled with superparamagnetic iron oxide (SPIO) using a dynamic MRI tracking method. SPIO labeled cells showed hypointense signal under the kidney subcapsules of diabetic mice on MRI, and faded gradually over the visiting time. However, new hypointense signal appeared in the spleen 1 week after transplantation, and became obvious with the time prolongation. Further histological examination proved the immigrated cells were insulin and C-peptide positive cells which were evenly distributed throughout the spleen. These intra-spleen insulin-producing cells maintained their protective effects against hyperglycemia in vivo, and these effects were reversed upon spleen removal. Transplantation of insulin-producing cells through spleen acquired an earlier blood glucose control as compared with that through kidney subcapsules. In summary, our data demonstrate that insulin-producing cells transplanted through kidney subcapsules were not located in situ but migrated into spleen, and rescues hyperglycemia in diabetic models. MRI may provide a novel tracking method for preclinical cell transplantation therapy of diabetes continuously and non-invasively.

  14. From Cell Differentiation to Cell Collectives: Bacillus subtilis Uses Division of Labor to Migrate

    PubMed Central

    van Gestel, Jordi; Vlamakis, Hera; Kolter, Roberto

    2015-01-01

    The organization of cells, emerging from cell–cell interactions, can give rise to collective properties. These properties are adaptive when together cells can face environmental challenges that they separately cannot. One particular challenge that is important for microorganisms is migration. In this study, we show how flagellum-independent migration is driven by the division of labor of two cell types that appear during Bacillus subtilis sliding motility. Cell collectives organize themselves into bundles (called “van Gogh bundles”) of tightly aligned cell chains that form filamentous loops at the colony edge. We show, by time-course microscopy, that these loops migrate by pushing themselves away from the colony. The formation of van Gogh bundles depends critically on the synergistic interaction of surfactin-producing and matrix-producing cells. We propose that surfactin-producing cells reduce the friction between cells and their substrate, thereby facilitating matrix-producing cells to form bundles. The folding properties of these bundles determine the rate of colony expansion. Our study illustrates how the simple organization of cells within a community can yield a strong ecological advantage. This is a key factor underlying the diverse origins of multicellularity. PMID:25894589

  15. Insulin-producing cells from embryonic stem cells rescues hyperglycemia via intra-spleen migration

    PubMed Central

    Ren, Meng; Shang, Changzhen; Zhong, Xiaomei; Guo, Ruomi; Lao, Guojuan; Wang, Xiaoyi; Cheng, Hua; Min, Jun; Yan, Li; Shen, Jun

    2014-01-01

    Implantation of embryonic stem cells (ESC)-derived insulin-producing cells has been extensively investigated for treatment of diabetes in animal models. However, the in vivo behavior and migration of transplanted cells in diabetic models remains unclear. Here we investigated the location and migration of insulin-producing cells labeled with superparamagnetic iron oxide (SPIO) using a dynamic MRI tracking method. SPIO labeled cells showed hypointense signal under the kidney subcapsules of diabetic mice on MRI, and faded gradually over the visiting time. However, new hypointense signal appeared in the spleen 1 week after transplantation, and became obvious with the time prolongation. Further histological examination proved the immigrated cells were insulin and C-peptide positive cells which were evenly distributed throughout the spleen. These intra-spleen insulin-producing cells maintained their protective effects against hyperglycemia in vivo, and these effects were reversed upon spleen removal. Transplantation of insulin-producing cells through spleen acquired an earlier blood glucose control as compared with that through kidney subcapsules. In summary, our data demonstrate that insulin-producing cells transplanted through kidney subcapsules were not located in situ but migrated into spleen, and rescues hyperglycemia in diabetic models. MRI may provide a novel tracking method for preclinical cell transplantation therapy of diabetes continuously and non-invasively. PMID:25533571

  16. Cinnamtannin B-1 Promotes Migration of Mesenchymal Stem Cells and Accelerates Wound Healing in Mice.

    PubMed

    Fujita, Kosuke; Kuge, Katsunori; Ozawa, Noriyasu; Sahara, Shunya; Zaiki, Kaori; Nakaoji, Koichi; Hamada, Kazuhiko; Takenaka, Yukiko; Tanahashi, Takao; Tamai, Katsuto; Kaneda, Yasufumi; Maeda, Akito

    2015-01-01

    Substances that enhance the migration of mesenchymal stem cells to damaged sites have the potential to improve the effectiveness of tissue repair. We previously found that ethanol extracts of Mallotus philippinensis bark promoted migration of mesenchymal stem cells and improved wound healing in a mouse model. We also demonstrated that bark extracts contain cinnamtannin B-1, a flavonoid with in vitro migratory activity against mesenchymal stem cells. However, the in vivo effects of cinnamtannin B-1 on the migration of mesenchymal stem cells and underlying mechanism of this action remain unknown. Therefore, we examined the effects of cinnamtannin B-1 on in vivo migration of mesenchymal stem cells and wound healing in mice. In addition, we characterized cinnamtannin B-1-induced migration of mesenchymal stem cells pharmacologically and structurally. The mobilization of endogenous mesenchymal stem cells into the blood circulation was enhanced in cinnamtannin B-1-treated mice as shown by flow cytometric analysis of peripheral blood cells. Whole animal imaging analysis using luciferase-expressing mesenchymal stem cells as a tracer revealed that cinnamtannin B-1 increased the homing of mesenchymal stem cells to wounds and accelerated healing in a diabetic mouse model. Additionally, the cinnamtannin B-1-induced migration of mesenchymal stem cells was pharmacologically susceptible to inhibitors of phosphatidylinositol 3-kinase, phospholipase C, lipoxygenase, and purines. Furthermore, biflavonoids with similar structural features to cinnamtannin B-1 also augmented the migration of mesenchymal stem cells by similar pharmacological mechanisms. These results demonstrate that cinnamtannin B-1 promoted mesenchymal stem cell migration in vivo and improved wound healing in mice. Furthermore, the results reveal that cinnamtannin B-1-induced migration of mesenchymal stem cells may be mediated by specific signaling pathways, and the flavonoid skeleton may be relevant to its effects on

  17. Cinnamtannin B-1 Promotes Migration of Mesenchymal Stem Cells and Accelerates Wound Healing in Mice.

    PubMed

    Fujita, Kosuke; Kuge, Katsunori; Ozawa, Noriyasu; Sahara, Shunya; Zaiki, Kaori; Nakaoji, Koichi; Hamada, Kazuhiko; Takenaka, Yukiko; Tanahashi, Takao; Tamai, Katsuto; Kaneda, Yasufumi; Maeda, Akito

    2015-01-01

    Substances that enhance the migration of mesenchymal stem cells to damaged sites have the potential to improve the effectiveness of tissue repair. We previously found that ethanol extracts of Mallotus philippinensis bark promoted migration of mesenchymal stem cells and improved wound healing in a mouse model. We also demonstrated that bark extracts contain cinnamtannin B-1, a flavonoid with in vitro migratory activity against mesenchymal stem cells. However, the in vivo effects of cinnamtannin B-1 on the migration of mesenchymal stem cells and underlying mechanism of this action remain unknown. Therefore, we examined the effects of cinnamtannin B-1 on in vivo migration of mesenchymal stem cells and wound healing in mice. In addition, we characterized cinnamtannin B-1-induced migration of mesenchymal stem cells pharmacologically and structurally. The mobilization of endogenous mesenchymal stem cells into the blood circulation was enhanced in cinnamtannin B-1-treated mice as shown by flow cytometric analysis of peripheral blood cells. Whole animal imaging analysis using luciferase-expressing mesenchymal stem cells as a tracer revealed that cinnamtannin B-1 increased the homing of mesenchymal stem cells to wounds and accelerated healing in a diabetic mouse model. Additionally, the cinnamtannin B-1-induced migration of mesenchymal stem cells was pharmacologically susceptible to inhibitors of phosphatidylinositol 3-kinase, phospholipase C, lipoxygenase, and purines. Furthermore, biflavonoids with similar structural features to cinnamtannin B-1 also augmented the migration of mesenchymal stem cells by similar pharmacological mechanisms. These results demonstrate that cinnamtannin B-1 promoted mesenchymal stem cell migration in vivo and improved wound healing in mice. Furthermore, the results reveal that cinnamtannin B-1-induced migration of mesenchymal stem cells may be mediated by specific signaling pathways, and the flavonoid skeleton may be relevant to its effects on

  18. Microbial desalination cell with capacitive adsorption for ion migration control.

    PubMed

    Forrestal, Casey; Xu, Pei; Jenkins, Peter E; Ren, Zhiyong

    2012-09-01

    A new microbial desalination cell with capacitive adsorption capability (cMDC) was developed to solve the ion migration problem facing current MDC systems. Traditional MDCs remove salts by transferring ions to the anode and cathode chambers, which may prohibit wastewater beneficial reuse due to increased salinity. The cMDC uses adsorptive activated carbon cloth (ACC) as the electrodes and utilizes the formed capacitive double layers for electrochemical ion adsorption. The cMDC removed an average of 69.4% of the salt from the desalination chamber through electrode adsorption during one batch cycle, and it did not add salts to the anode or cathode chamber. It was estimated that 61-82.2mg of total dissolved solids (TDS) was adsorbed to 1g of ACC electrode. The cMDC provides a new approach for salt management, organic removal, and energy production. Further studies will be conducted to optimize reactor configuration and achieve in situ electrode regeneration.

  19. Inhibition of corneal epithelial cell migration by cadmium and mercury

    SciTech Connect

    Ubels, J.L.; Osgood, T.B. Medical Coll. of Wisconsin, Milwaukee )

    1991-02-01

    In a previous comparative study of corneal healing in fish, the authors observed that corneal epithelial healing occurs very rapidly in vivo in the marine teleost Myoxocephalus octodecimspinosus (longhorn sculpin) with a 6-mm diameter wound on the mammalian cornea. This rapid healing which permits prompt restoration of the epithelial barrier is apparently an adaptation to the large ionic and osmotic gradients between the environment and the intraocular fluids of the fish. These observations suggested that epithelial healing in the sculpin cornea might be useful model in aquatic biomedical toxicology if an in vitro method for measurement of healing rates could be developed. In this report the authors demonstrate that sculpin eyes maintained in short-term organ culture have a rapid corneal epithelial healing response and that this model can be used to demonstrate the toxic effects of heavy metals on epithelial cell migration.

  20. Downregulation of SENP1 inhibits cell proliferation, migration and promotes apoptosis in human glioma cells

    PubMed Central

    ZHANG, QIU-SHENG; ZHANG, MENG; HUANG, XIAN-JIAN; LIU, XIAO-JIA; LI, WEI-PING

    2016-01-01

    Small ubiquitin-related modifier protein (SUMO) is an evolutionarily conserved protein in a broad range of eukaryotic organisms. De-SUMOylation, the reverse reaction of SUMOylation, is regulated by a family of SUMO-specific proteases (SENPs). SENP1 is a member of the de-SUMOylation protease family involved in the de-SUMOylation of a variety of SUMOylated proteins. The present study demonstrates that small hairpin RNA (shRNA)-mediated downregulation of SENP1 inhibits cell proliferation and migration, and promotes apoptosis in human glioma cells. Firstly, LN-299 cells were transfected with a plasmid expressing SENP1 shRNA (pGenesil-1-SENP1). The messenger RNA and protein expression of SENP1 was detected by reverse transcription-quantitative polymerase chain reaction and western blot analysis, respectively. Cell proliferation in vitro was assessed using a methyl thiazolyl tetrazolium assay. Flow cytometry (FCM) was used to detect the apoptosis of LN-299 cells. The effect of the downregulation of SENP1 on cell migration was detected by a Transwell migration system. The present results showed that, compared with the control shRNA group, the expression of SENP1 was significantly reduced in the SENP1 shRNA group. The proliferation was markedly inhibited in the SENP1 shRNA group. FCM findings revealed that apoptosis increased significantly in the SENP1 shRNA group. In addition, it was found that downregulation of SENP1 evidently suppressed tumor cell migration. Downregulation of SENP1 expression inhibited the proliferation and migration and promoted apoptosis in LN-299 cells. These results indirectly demonstrate that SENP1 is likely to play a critical role in human glioma cells. PMID:27347128

  1. Impaired SIRT1 promotes the migration of vascular smooth muscle cell-derived foam cells.

    PubMed

    Zhang, Ming-Jie; Zhou, Yi; Chen, Lei; Wang, Xu; Pi, Yan; Long, Chun-Yan; Sun, Meng-Jiao; Chen, Xue; Gao, Chang-Yue; Li, Jing-Cheng; Zhang, Li-Li

    2016-07-01

    The formation of fat-laden foam cells, contributing to the fatty streaks of the plaques of atheroma, is the critical early process in atherosclerosis. The previous study demonstrated that vascular smooth muscle cells (VSMCs) contain a much larger burden of the excess cholesterol in comparison with monocyte-derived macrophages in human coronary atherosclerosis, as the main origin of foam cells. It is noteworthy that VSMC-derived foam cells are deposited in subintima but not media, where VSMCs normally deposit in. Therefore, migration from media to intima is an indispensable step for a VSMC to accrue neutral lipids and form foam cell. Whether this migration occurs paralleled with or prior to the formation of foam cell is still unclear. Herein, the present study was designed to test the VSMC migratory capability in the process of foam cell formation induced by oxidized low-density lipoprotein (oxLDL). In conclusion, we provide evidence that oxLDL induces the VSMC-derived foam cells formation with increased migration ability and MMP-9 expression, which were partly attributed to the impaired SIRT1 and enhanced nuclear factor-kappa B (NF-κB) activity. As activation of transient receptor potential vanilloid type 1 (TRPV1) has been reported to have anti-atherosclerotic effects, we investigated its role in oxLDL-treated VSMC migration. It is found that activating TRPV1 by capsaicin inhibits VSMC foam cell formation and the accompanied migration through rescuing the SIRT1 and suppressing NF-κB signaling. The present study provides evidence that SIRT1 may be a promising intervention target of atherosclerosis, and raises the prospect of TRPV1 in prevention and treatment of atherosclerosis.

  2. Discovery of the migrasome, an organelle mediating release of cytoplasmic contents during cell migration

    PubMed Central

    Ma, Liang; Li, Ying; Peng, Junya; Wu, Danni; Zhao, Xiaoxin; Cui, Yitong; Chen, Lilian; Yan, Xiaojun; Du, Yanan; Yu, Li

    2015-01-01

    Cells communicate with each other through secreting and releasing proteins and vesicles. Many cells can migrate. In this study, we report the discovery of migracytosis, a cell migration-dependent mechanism for releasing cellular contents, and migrasomes, the vesicular structures that mediate migracytosis. As migrating cells move, they leave long tubular strands, called retraction fibers, behind them. Large vesicles, which contain numerous smaller vesicles, grow on the tips and intersections of retraction fibers. These fibers, which connect the vesicles with the main cell body, eventually break, and the vesicles are released into the extracellular space or directly taken up by surrounding cells. Since the formation of these vesicles is migration-dependent, we named them “migrasomes”. We also found that cytosolic contents can be transported into migrasomes and released from the cell through migrasomes. We named this migration-dependent release mechanism “migracytosis”. PMID:25342562

  3. The acetylenic tricyclic bis(cyano enone), TBE-31, targets microtubule dynamics and cell polarity in migrating cells.

    PubMed

    Chan, Eddie; Saito, Akira; Honda, Tadashi; Di Guglielmo, Gianni M

    2016-04-01

    Cell migration is dependent on the microtubule network for structural support as well as for the proper delivery and positioning of polarity proteins at the leading edge of migrating cells. Identification of drugs that target cytoskeletal-dependent cell migration and protein transport in polarized migrating cells is important in understanding the cell biology of normal and tumor cells and can lead to new therapeutic targets in disease processes. Here, we show that the tricyclic compound TBE-31 directly binds to tubulin and interferes with microtubule dynamics, as assessed by end binding 1 (EB1) live cell imaging. Interestingly, this interference is independent of in vitro tubulin polymerization. Using immunofluorescence microscopy, we also observed that TBE-31 interferes with the polarity of migratory cells. The polarity proteins Rac1, IQGAP and Tiam1 were localized at the leading edge of DMSO-treated migrating cell, but were observed to be in multiple protrusions around the cell periphery of TBE-31-treated cells. Finally, we observed that TBE-31 inhibits the migration of Rat2 fibroblasts with an IC50 of 0.75 μM. Taken together, our results suggest that the inhibition of cell migration by TBE-31 may result from the improper maintenance of cell polarity of migrating cells.

  4. The acetylenic tricyclic bis(cyano enone), TBE-31, targets microtubule dynamics and cell polarity in migrating cells.

    PubMed

    Chan, Eddie; Saito, Akira; Honda, Tadashi; Di Guglielmo, Gianni M

    2016-04-01

    Cell migration is dependent on the microtubule network for structural support as well as for the proper delivery and positioning of polarity proteins at the leading edge of migrating cells. Identification of drugs that target cytoskeletal-dependent cell migration and protein transport in polarized migrating cells is important in understanding the cell biology of normal and tumor cells and can lead to new therapeutic targets in disease processes. Here, we show that the tricyclic compound TBE-31 directly binds to tubulin and interferes with microtubule dynamics, as assessed by end binding 1 (EB1) live cell imaging. Interestingly, this interference is independent of in vitro tubulin polymerization. Using immunofluorescence microscopy, we also observed that TBE-31 interferes with the polarity of migratory cells. The polarity proteins Rac1, IQGAP and Tiam1 were localized at the leading edge of DMSO-treated migrating cell, but were observed to be in multiple protrusions around the cell periphery of TBE-31-treated cells. Finally, we observed that TBE-31 inhibits the migration of Rat2 fibroblasts with an IC50 of 0.75 μM. Taken together, our results suggest that the inhibition of cell migration by TBE-31 may result from the improper maintenance of cell polarity of migrating cells. PMID:26775215

  5. Three consecutive days of interval runs to exhaustion affects lymphocyte subset apoptosis and migration.

    PubMed

    Navalta, James W; Tibana, Ramires Alsamir; Fedor, Elizabeth A; Vieira, Amilton; Prestes, Jonato

    2014-01-01

    This investigation assessed the lymphocyte subset response to three days of intermittent run exercise to exhaustion. Twelve healthy college-aged males (n = 8) and females (n = 4) (age = 26 ± 4 years; height = 170.2 ± 10 cm; body mass = 75 ± 18 kg) completed an exertion test (maximal running speed and VO2max) and later performed three consecutive days of an intermittent run protocol to exhaustion (30 sec at maximal running speed and 30 sec at half of the maximal running speed). Blood was collected before exercise (PRE) and immediately following the treadmill bout (POST) each day. When the absolute change from baseline was evaluated (i. e., Δ baseline), a significant change in CD4+ and CD8+ for CX3CR1 cells was observed by completion of the third day. Significant changes in both apoptosis and migration were observed following two consecutive days in CD19+ lymphocytes, and the influence of apoptosis persisted following the third day. Given these lymphocyte responses, it is recommended that a rest day be incorporated following two consecutive days of a high-intensity intermittent run program to minimize immune cell modulations and reduce potential susceptibility. PMID:24895602

  6. PLCβ3 mediates cortactin interaction with WAVE2 in MCP1-induced actin polymerization and cell migration

    PubMed Central

    Janjanam, Jagadeesh; Chandaka, Giri Kumar; Kotla, Sivareddy; Rao, Gadiparthi N.

    2015-01-01

    Monocyte chemotactic protein 1 (MCP1) stimulates vascular smooth muscle cell (VSMC) migration in vascular wall remodeling. However, the mechanisms underlying MCP1-induced VSMC migration have not been understood. Here we identify the signaling pathway associated with MCP1-induced human aortic smooth muscle cell (HASMC) migration. MCP1, a G protein–coupled receptor agonist, activates phosphorylation of cortactin on S405 and S418 residues in a time-dependent manner, and inhibition of its phosphorylation attenuates MCP1-induced HASMC G-actin polymerization, F-actin stress fiber formation, and migration. Cortactin phosphorylation on S405/S418 is found to be critical for its interaction with WAVE2, a member of the WASP family of cytoskeletal regulatory proteins required for cell migration. In addition, the MCP1-induced cortactin phosphorylation is dependent on PLCβ3-mediated PKCδ activation, and siRNA-mediated down-regulation of either of these molecules prevents cortactin interaction with WAVE2, affecting G-actin polymerization, F-actin stress fiber formation, and HASMC migration. Upstream, MCP1 activates CCR2 and Gαq/11 in a time-dependent manner, and down-regulation of their levels attenuates MCP1-induced PLCβ3 and PKCδ activation, cortactin phosphorylation, cortactin–WAVE2 interaction, G-actin polymerization, F-actin stress fiber formation, and HASMC migration. Together these findings demonstrate that phosphorylation of cortactin on S405 and S418 residues is required for its interaction with WAVE2 in MCP1-induced cytoskeleton remodeling, facilitating HASMC migration. PMID:26490115

  7. The influence of ischemic factors on the migration rates of cell types involved in cutaneous and subcutaneous pressure ulcers.

    PubMed

    Topman, Gil; Lin, Feng-Huei; Gefen, Amit

    2012-09-01

    A pressure ulcer (PU) is a localized injury to the skin and/or to underlying tissues, typically over a weight-bearing bony prominence. PUs often develop in ischemic tissues. Other than being relevant to the etiology of PUs, ischemic factors such as glucose levels, acidity and temperature could potentially affect healing processes as well, particularly, the rate of damage repair. Using an in vitro cell culture model, the goal of the present study was to determine the influence of ischemic factors: low temperature (35 °C), low glucose (1 g/L) and acidic pH (6.7) on the migration rate of NIH3T3 fibroblasts, 3T3L1 preadipocytes and C2C12 myoblasts, which could all be affected by PUs. Cell migration into a local damage site, produced by crushing cells under a micro-indentor, was monitored over ~16 h under controlled temperature and pH conditions. We found that in the NIH3T3 cultures, acidosis significantly hindered the migration rate as well as delayed the times for onset and end of mass cell migration. The effects of temperature and glucose however were not significant. Additionally, under control conditions (temperature 37 °C, glucose 4.5 g/L, pH 7.6), migration rates and times differed significantly across the different cell types. The present findings motivate further studies related to the effects of pH levels on migration performances, particularly in PU where bacterial contamination-associated with an acidic environment-is involved.

  8. Multi-function microsystem for cells migration analysis and evaluation of photodynamic therapy procedure in coculture

    PubMed Central

    Jastrzebska (Jedrych), Elzbieta; Grabowska-Jadach, Ilona; Chudy, Michal; Dybko, Artur; Brzozka, Zbigniew

    2012-01-01

    Cell migration is an important physiological process, which is involved in cancer metastasis. Therefore, the investigation of cell migration may lead to the development of novel therapeutic approaches. In this study, we have successfully developed a microsystem for culture of two cell types (non-malignant and carcinoma) and for analysis of cell migration dependence on distance between them. Finally, we studied quantitatively the influence of photodynamic therapy (PDT) procedures on the viability of pairs of non-malignant (MRC5 or Balb/3T3) and carcinoma (A549) cells coculture. The proposed geometry of the microsystem allowed for separate introduction of two cell lines and analysis of cells migration dependence on distance between the cells. We found that a length of connecting microchannel has an influence on cell migration and viability of non-malignant cells after PDT procedure. Summarizing, the developed microsystem can constitute a new tool for carrying out experiments, which offers a few functions: cell migration analysis, carcinoma and non-malignant cells coculture, and evaluation of PDT procedure in the various steps of cell migration. PMID:24339849

  9. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    NASA Astrophysics Data System (ADS)

    Zhang, Hanyuan; Lohcharoenkal, Warangkana; Sun, Jianbo; Li, Xiang; Wang, Liying; Wu, Nianqiang; Rojanasakul, Yon; Liu, Yuxin

    2015-07-01

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 µg cm-2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  10. Attenuation of LDHA expression in cancer cells leads to redox-dependent alterations in cytoskeletal structure and cell migration.

    PubMed

    Arseneault, Robert; Chien, Andrew; Newington, Jordan T; Rappon, Tim; Harris, Richard; Cumming, Robert C

    2013-09-28

    Aerobic glycolysis, the preferential use of glycolysis even in the presence of oxygen to meet cellular metabolic demands, is a near universal feature of cancer. This unique type of metabolism is thought to protect cancer cells from damaging reactive oxygen species (ROS) produced in the mitochondria. Using the cancer cell line MDA-MB-435 it is shown that shRNA mediated knockdown of lactate dehydrogenase A (LDHA), a key mediator of aerobic glycolysis, results in elevated mitochondrial ROS production and a concomitant decrease in cell proliferation and motility. Redox-sensitive proteins affected by oxidative stress associated with LDHA knockdown were identified by Redox 2D-PAGE and mass spectrometry. In particular, tropomyosin (Tm) isoforms Tm4, Tm5NM1 and Tm5NM5, proteins involved in cell migration and cytoskeletal dynamics, exhibited changes in disulfide bonding and co-localized with peri-nuclear actin aggregates in LDHA knockdown cells. In contrast, treatment with the thiol-based antioxidant N-acetylcysteine promoted the relocalization of Tms to cortical actin microfilaments and partially rescued the migration defects associated with attenuated LDHA expression. These results suggest that aerobic glycolysis and reduced mitochondrial ROS production create an environment conducive to cytoskeletal remodeling; key events linked to the high cell motility associated with cancer.

  11. Inhibiting cell migration and cell invasion by silencing the transcription factor ETS-1 in human bladder cancer

    PubMed Central

    Chen, Mingwei; Wu, Hanwei; Lin, Muqi; Zhan, Yonghao; Zhuang, Chengle; Lin, Junhao; Li, Jianfa; Xu, Wen; Fu, Xing; Zhang, Qiaoxia; Sun, Xiaojuan; Zhao, Guoping; Huang, Weiren

    2016-01-01

    As one of the members of the ETS gene family, the transcription factor v-ets avian erythroblastosis virus E26 oncogene homolog 1 (ETS-1) plays key role in the regulation of physiological processes in normal cells and tumors. In this study, we aimed to investigate the relationship between the transcription factor ETS-1 and malignant phenotypes of bladder cancer. We demonstrated that ETS-1 was up-regulated in human bladder cancer tissue compared to paired normal bladder tissue. In order to evaluate the functional role of ETS-1 in human bladder cancer, vectors expressing ETS-1 shRNA and ETS-1 protein were constructed in vitro and transfected into the human bladder cancer T24 and 5637 cells. Our results showed that the transcription factor ETS-1 could promote cell migration and cell invasion in human bladder cancer, without affecting cell proliferation and apoptosis. In conclusion, ETS-1 plays oncogenic roles through inducing cell migration and invasion in human bladder cancer, and it can be used as a therapeutic target for treating human bladder cancer. PMID:27036016

  12. Inhibiting cell migration and cell invasion by silencing the transcription factor ETS-1 in human bladder cancer.

    PubMed

    Liu, Li; Liu, Yuchen; Zhang, Xintao; Chen, Mingwei; Wu, Hanwei; Lin, Muqi; Zhan, Yonghao; Zhuang, Chengle; Lin, Junhao; Li, Jianfa; Xu, Wen; Fu, Xing; Zhang, Qiaoxia; Sun, Xiaojuan; Zhao, Guoping; Huang, Weiren

    2016-05-01

    As one of the members of the ETS gene family, the transcription factor v-ets avian erythroblastosis virus E26 oncogene homolog 1 (ETS-1) plays key role in the regulation of physiological processes in normal cells and tumors. In this study, we aimed to investigate the relationship between the transcription factor ETS-1 and malignant phenotypes of bladder cancer. We demonstrated that ETS-1 was up-regulated in human bladder cancer tissue compared to paired normal bladder tissue. In order to evaluate the functional role of ETS-1 in human bladder cancer, vectors expressing ETS-1 shRNA and ETS-1 protein were constructed in vitro and transfected into the human bladder cancer T24 and 5637 cells. Our results showed that the transcription factor ETS-1 could promote cell migration and cell invasion in human bladder cancer, without affecting cell proliferation and apoptosis. In conclusion, ETS-1 plays oncogenic roles through inducing cell migration and invasion in human bladder cancer, and it can be used as a therapeutic target for treating human bladder cancer.

  13. Progesterone promotes cell migration, invasion and cofilin activation in human astrocytoma cells.

    PubMed

    Piña-Medina, Ana Gabriela; Hansberg-Pastor, Valeria; González-Arenas, Aliesha; Cerbón, Marco; Camacho-Arroyo, Ignacio

    2016-01-01

    Astrocytomas are the most common and aggressive primary brain tumors in humans. Invasiveness of these tumors has been attributed in part to deregulation of cell motility-dependent cytoskeletal dynamics that involves actin-binding proteins such as cofilin. Progesterone (P4) has been found to induce migration and invasion of cells derived from breast cancer and endothelium. However, the role of P4 in migration and invasion of astrocytoma cells as well as its effects on astrocytomas cytoskeleton remodeling is not known. In this work we evaluated these aspects in D54 and U251 cells derived from human astrocytomas from the highest degree of malignancy (grade IV, glioblastoma). Our results showed that in scratch-wound assays P4 increased the number of D54 and U251 cells migrating from 3 to 48 h. Both RU486, a P4 receptor (PR) antagonist, and an oligonucleotide antisense against PR significantly blocked P4 effects. Transwell assays showed that P4 significantly increased the number of invasive cells at 24h. As in the case of migration, this effect was blocked by RU486. Finally, by Western blotting, an increase in the cofilin/p-cofilin ratio at 15 and 30 min and a decrease at 30 and 60 min in U251 and D54 cells, respectively, was observed after P4, P4+RU486 and RU486 treatments. These data suggest that P4 increases human astrocytoma cells migration and invasion through its intracellular receptor, and that cofilin activation by P4 is independent of PR action. PMID:26639431

  14. P-cadherin-mediated Rho GTPase regulation during collective cell migration

    PubMed Central

    Plutoni, Cédric; Bazellières, Elsa; Gauthier-Rouvière, Cécile

    2016-01-01

    ABSTRACT This commentary addresses the role of P-cadherin in collective cell migration (CCM), a cooperative and coordinated migration mode, used by cells during normal and pathological migration processes. We discuss how cadherin-mediated cell-cell junctions (CCJs) play a critical role in CCM through their ability to regulate Rho GTPase-dependent pathways and how this leads to the generation and orientation of mechanical forces. We will also highlight the key function of P-cadherin (a poor prognostic marker in several tumors) in promoting collective cell movement in epithelial and mesenchymal cells. PMID:27152729

  15. ASB2α regulates migration of immature dendritic cells.

    PubMed

    Lamsoul, Isabelle; Métais, Arnaud; Gouot, Emmanuelle; Heuzé, Mélina L; Lennon-Duménil, Ana-Maria; Moog-Lutz, Christel; Lutz, Pierre G

    2013-07-25

    The actin-binding protein filamins (FLNs) are major organizers of the actin cytoskeleton. They control the elasticity and stiffness of the actin network and provide connections with the extracellular microenvironment by anchoring transmembrane receptors to the actin filaments. Although numerous studies have revealed the importance of FLN levels, relatively little is known about the regulation of its stability in physiological relevant settings. Here, we show that the ASB2α cullin 5-ring E3 ubiquitin ligase is highly expressed in immature dendritic cells (DCs) and is down-regulated after DC maturation. We further demonstrate that FLNs are substrates of ASB2α in immature DCs and therefore are not stably expressed in these cells, whereas they exhibit high levels of expression in mature DCs. Using ASB2 conditional knockout mice, we show that ASB2α is a critical regulator of cell spreading and podosome rosette formation in immature DCs. Furthermore, we show that ASB2(-/-) immature DCs exhibit reduced matrix-degrading function leading to defective migration. Altogether, our results point to ASB2α and FLNs as newcomers in DC biology. PMID:23632887

  16. ASB2α regulates migration of immature dendritic cells.

    PubMed

    Lamsoul, Isabelle; Métais, Arnaud; Gouot, Emmanuelle; Heuzé, Mélina L; Lennon-Duménil, Ana-Maria; Moog-Lutz, Christel; Lutz, Pierre G

    2013-07-25

    The actin-binding protein filamins (FLNs) are major organizers of the actin cytoskeleton. They control the elasticity and stiffness of the actin network and provide connections with the extracellular microenvironment by anchoring transmembrane receptors to the actin filaments. Although numerous studies have revealed the importance of FLN levels, relatively little is known about the regulation of its stability in physiological relevant settings. Here, we show that the ASB2α cullin 5-ring E3 ubiquitin ligase is highly expressed in immature dendritic cells (DCs) and is down-regulated after DC maturation. We further demonstrate that FLNs are substrates of ASB2α in immature DCs and therefore are not stably expressed in these cells, whereas they exhibit high levels of expression in mature DCs. Using ASB2 conditional knockout mice, we show that ASB2α is a critical regulator of cell spreading and podosome rosette formation in immature DCs. Furthermore, we show that ASB2(-/-) immature DCs exhibit reduced matrix-degrading function leading to defective migration. Altogether, our results point to ASB2α and FLNs as newcomers in DC biology.

  17. Subcellular optogenetic activation of Cdc42 controls local and distal signaling to drive immune cell migration

    PubMed Central

    O’Neill, Patrick R.; Kalyanaraman, Vani; Gautam, N.

    2016-01-01

    Migratory immune cells use intracellular signaling networks to generate and orient spatially polarized responses to extracellular cues. The monomeric G protein Cdc42 is believed to play an important role in controlling the polarized responses, but it has been difficult to determine directly the consequences of localized Cdc42 activation within an immune cell. Here we used subcellular optogenetics to determine how Cdc42 activation at one side of a cell affects both cell behavior and dynamic molecular responses throughout the cell. We found that localized Cdc42 activation is sufficient to generate polarized signaling and directional cell migration. The optically activated region becomes the leading edge of the cell, with Cdc42 activating Rac and generating membrane protrusions driven by the actin cytoskeleton. Cdc42 also exerts long-range effects that cause myosin accumulation at the opposite side of the cell and actomyosin-mediated retraction of the cell rear. This process requires the RhoA-activated kinase ROCK, suggesting that Cdc42 activation at one side of a cell triggers increased RhoA signaling at the opposite side. Our results demonstrate how dynamic, subcellular perturbation of an individual signaling protein can help to determine its role in controlling polarized cellular responses. PMID:26941336

  18. IL-10 Conditioning of Human Skin Affects the Distribution of Migratory Dendritic Cell Subsets and Functional T Cell Differentiation

    PubMed Central

    Lindenberg, Jelle J.; Oosterhoff, Dinja; Sombroek, Claudia C.; Lougheed, Sinéad M.; Hooijberg, Erik; Stam, Anita G. M.; Santegoets, Saskia J. A. M.; Tijssen, Henk J.; Buter, Jan; Pinedo, Herbert M.; van den Eertwegh, Alfons J. M.; Scheper, Rik J.; Koenen, Hans J. P. M.; van de Ven, Rieneke; de Gruijl, Tanja D.

    2013-01-01

    In cancer patients pervasive systemic suppression of Dendritic Cell (DC) differentiation and maturation can hinder vaccination efficacy. In this study we have extensively characterized migratory DC subsets from human skin and studied how their migration and T cell-stimulatory abilities were affected by conditioning of the dermal microenvironment through cancer-related suppressive cytokines. To assess effects in the context of a complex tissue structure, we made use of a near-physiological skin explant model. By 4-color flow cytometry, we identified migrated Langerhans Cells (LC) and five dermis-derived DC populations in differential states of maturation. From a panel of known tumor-associated suppressive cytokines, IL-10 showed a unique ability to induce predominant migration of an immature CD14+CD141+DC-SIGN+ DC subset with low levels of co-stimulatory molecules, up-regulated expression of the co-inhibitory molecule PD-L1 and the M2-associated macrophage marker CD163. A similarly immature subset composition was observed for DC migrating from explants taken from skin overlying breast tumors. Whereas predominant migration of mature CD1a+ subsets was associated with release of IL-12p70, efficient Th cell expansion with a Th1 profile, and expansion of functional MART-1-specific CD8+ T cells, migration of immature CD14+ DDC was accompanied by increased release of IL-10, poor expansion of CD4+ and CD8+ T cells, and skewing of Th responses to favor coordinated FoxP3 and IL-10 expression and regulatory T cell differentiation and outgrowth. Thus, high levels of IL-10 impact the composition of skin-emigrated DC subsets and appear to favor migration of M2-like immature DC with functional qualities conducive to T cell tolerance. PMID:23875023

  19. Nerve growth factor and its low-affinity receptor promote Schwann cell migration.

    PubMed Central

    Anton, E S; Weskamp, G; Reichardt, L F; Matthew, W D

    1994-01-01

    Migrating Schwann cells in developing or regenerating peripheral nerves are known to express dramatically increased levels of nerve growth factor (NGF) and the low-affinity NGF receptor (LNGFR). Schwann cells do not express detectable pp140trk, the NGF-activated receptor tyrosine kinase which is essential for neuronal responses to NGF. The temporal correlation observed in Schwann cells between migration and the enhanced expression of NGF and LNGFR suggests that NGF and LNGFR may promote Schwann cell migration. To test this possibility, we examined the effects of NGF on Schwann cell migration on cryostat sections of biologically relevant NGF-poor and NGF-rich substrates--normal or denervated peripheral (sciatic) nerve, untreated or pretreated with NGF. Results show that Schwann cells migrate more rapidly on denervated than on normal sciatic nerve. Antibodies to NGF or to LNGFR strongly, but incompletely, inhibit enhanced migration on denervated nerves. Pretreatment of denervated nerve sections with NGF increases further the rate of Schwann cell migration. The same antibodies to NGF or to LNGFR abolish this response. These results suggest that one function of the elevated levels of NGF known to be present in embryonic and regenerating peripheral nerves is to promote the migration of Schwann cells. In contrast to neurons, where pp140trk appears to be the functionally critical NGF receptor, NGF responses in Schwann cells depend on LNGFR. Images PMID:8146193

  20. ProBDNF inhibits collective migration and chemotaxis of rat Schwann cells.

    PubMed

    Ding, You-Quan; Li, Xuan-Yang; Xia, Guan-Nan; Ren, Hong-Yi; Zhou, Xin-Fu; Su, Bing-Yin; Qi, Jian-Guo

    2016-10-01

    Schwann cell migration, including collective migration and chemotaxis, is essential for the formation of coordinate interactions between Schwann cells and axons during peripheral nerve development and regeneration. Moreover, limited migration of Schwann cells imposed a serious obstacle on Schwann cell-astrocytes intermingling and spinal cord repair after Schwann cell transplantation into injured spinal cords. Recent studies have shown that mature brain-derived neurotrophic factor, a member of the neurotrophin family, inhibits Schwann cell migration. The precursor form of brain-derived neurotrophic factor, proBDNF, was expressed in the developing or degenerating peripheral nerves and the injured spinal cords. Since "the yin and yang of neurotrophin action" has been established as a common sense, proBDNF would be expected to promote Schwann cell migration. However, we found, in the present study, that exogenous proBDNF also inhibited in vitro collective migration and chemotaxis of RSC 96 cells, a spontaneously immortalized rat Schwann cell line. Moreover, proBDNF suppressed adhesion and spreading of those cells. At molecular level, proBDNF inhibits F-actin polymerization and focal adhesion dynamics in cultured RSC 96 cells. Therefore, our results suggested a special case against the classical opinion of "the yin and yang of neurotrophin action" and implied that proBDNF might modulate peripheral nerve development or regeneration and spinal cord repair through perturbing native or transplanted Schwann cell migration.

  1. Coexpressing shRNA with fluorescence tags for quantification of cell migration studies.

    PubMed

    Koo, Christine Xing'er; Fang, Wanru; Salto-Tellez, Manuel; Leong, David Tai

    2012-07-01

    Understanding migration of cells has many implications in human physiology; some examples include developmental biology, healing, immune responses and tissue remodeling. On the other hand, invasive migration by tumor cells is pathological and is a major cause of mortality amongst cancer sufferers. Cell migration assays have been widely used to quantify potentially metastatic genes. In recent years, the use of RNAi has significantly increased the tools available in cell migration research due to its specific gene targeting for knockdown. The inability to ensure 100% transfection/transduction efficiency reduces the sensitivity of cell migration assays because cells not successfully transfected/transduced with the RNAi are also included in the calculations. This study introduces a different experimental setup mathematically expressed in our named normalized relative infected cell count (N-RICC) that analyses cell migration assays by co-expressing retrovirally transduced shRNA with fluorescence tags from a single vector. Vectors transduced into cells are visible under fluorescence, thus alleviating the problems involved with transduction efficiency by individually identifying cells with targeted genes. Designed shRNAs were targeted against a list of potentially metastatic genes in a highly migratory breast cancer cell line model, MDA-MB-231. We have successfully applied N-RICC analysis to show greater sensitivity of integrin alpha5 (ITGA5) and Ras homologue A (RhoA) in cell metastasis over conventional methods in scratch-wound assays and migration chambers assays.

  2. Regulation No. 44 of 11 September 1989 on the development of areas affected by migration.

    PubMed

    1989-01-01

    Among other things, this Bulgarian Regulation establishes the following measures to aid the development of districts affected by migration: 1) local councils shall lease municipal land, buildings, and other property to newcomers for periods of at least 10 years; after the 10-year period has passed the lessee shall acquire title to the leased land or premises and be exempted from paying a transfer tax; 2) the State Savings Bank shall extend to the people of these districts loans for the construction of houses and farm buildings and reconstruction of living premises, with the state paying the interest on the loans; 3) new residents who have to change professions shall receive monetary benefits for up to 6 months during the time they are changing professions; 4) new residents employed in agriculture shall be exempted from payment of income taxes for 5 years; 5) transportation expenses incurred by new residents and their families during the process of resettlement are to be paid by the state; 6) persons under 35 who have graduated from high school shall be admitted to engineering, agriculture, and economic institutions of higher education without taking an entrance exam, if they agree to return to these districts after graduation and work there for no fewer than 6 years; and 7) retired persons working in these districts shall be entitled to receive full remuneration for their work, as well as full pensions.

  3. Regulation No. 44 of 11 September 1989 on the development of areas affected by migration.

    PubMed

    1989-01-01

    Among other things, this Bulgarian Regulation establishes the following measures to aid the development of districts affected by migration: 1) local councils shall lease municipal land, buildings, and other property to newcomers for periods of at least 10 years; after the 10-year period has passed the lessee shall acquire title to the leased land or premises and be exempted from paying a transfer tax; 2) the State Savings Bank shall extend to the people of these districts loans for the construction of houses and farm buildings and reconstruction of living premises, with the state paying the interest on the loans; 3) new residents who have to change professions shall receive monetary benefits for up to 6 months during the time they are changing professions; 4) new residents employed in agriculture shall be exempted from payment of income taxes for 5 years; 5) transportation expenses incurred by new residents and their families during the process of resettlement are to be paid by the state; 6) persons under 35 who have graduated from high school shall be admitted to engineering, agriculture, and economic institutions of higher education without taking an entrance exam, if they agree to return to these districts after graduation and work there for no fewer than 6 years; and 7) retired persons working in these districts shall be entitled to receive full remuneration for their work, as well as full pensions. PMID:12344255

  4. Crystalline Grain Interior Configuration Affects Lithium Migration Kinetics in Li-Rich Layered Oxide.

    PubMed

    Yu, Haijun; So, Yeong-Gi; Kuwabara, Akihide; Tochigi, Eita; Shibata, Naoya; Kudo, Tetsuichi; Zhou, Haoshen; Ikuhara, Yuichi

    2016-05-11

    The electrode kinetics of Li-ion batteries, which are important for battery utilization in electric vehicles, are affected by the grain size, crystal orientation, and surface structure of electrode materials. However, the kinetic influences of the grain interior structure and element segregation are poorly understood, especially for Li-rich layered oxides with complex crystalline structures and unclear electrochemical phenomena. In this work, cross-sectional thin transmission electron microscopy specimens are "anatomized" from pristine Li1.2Mn0.567Ni0.167Co0.067O2 powders using a new argon ion slicer technique. Utilizing advanced microscopy techniques, the interior configuration of a single grain, multiple monocrystal-like domains, and nickel-segregated domain boundaries are clearly revealed; furthermore, a randomly distributed atomic-resolution Li2MnO3-like with an intergrown LiTMO2 (TM = transitional metals) "twin domain" is demonstrated to exist in each domain. Further theoretical calculations based on the Li2MnO3-like crystal domain boundary model reveal that Li(+) migration in the Li2MnO3-like structure with domain boundaries is sluggish, especially when the nickel is segregated in domain boundaries. Our work uncovers the complex configuration of the crystalline grain interior and provides a conceptual advance in our understanding of the electrochemical performance of several compounds for Li-ion batteries. PMID:27088669

  5. Established and Novel Methods of Interrogating Two-Dimensional Cell Migration

    PubMed Central

    Ashby, William J.; Zijlstra, Andries

    2014-01-01

    The regulation of cell motility is central to living systems. Consequently, cell migration assays are some of the most frequently used in vitro assays. This article provides a comprehensive, detailed review of in vitro cell migration assays both currently in use and possible with existing technology. Emphasis is given to two-dimensional migration assays using densely organized cells such as the scratch assay. Assays are compared and categorized in an outline format according to their primary biological readout and physical parameters. The individual benefits of the various methods and quantification strategies are also discussed. This review provides an in-depth, structured overview of in vitro cell migration assays as a means of enabling the reader to make informed decisions among the growing number of options available for their specific cell migration application. PMID:23038152

  6. Mechanistic adaptability of cancer cells strongly affects anti-migratory drug efficacy.

    PubMed

    Sun, Wei; Lim, Chwee Teck; Kurniawan, Nicholas Agung

    2014-10-01

    Cancer metastasis involves the dissemination of cancer cells from the primary tumour site and is responsible for the majority of solid tumour-related mortality. Screening of anti-metastasis drugs often includes functional assays that examine cancer cell invasion inside a three-dimensional hydrogel that mimics the extracellular matrix (ECM). Here, we built a mechanically tuneable collagen hydrogel model to recapitulate cancer spreading into heterogeneous tumour stroma and monitored the three-dimensional invasion of highly malignant breast cancer cells, MDA-MB-231. Migration assays were carried out in the presence and the absence of drugs affecting four typical molecular mechanisms involved in cell migration, as well as under five ECMs with different biophysical properties. Strikingly, the effects of the drugs were observed to vary strongly with matrix mechanics and microarchitecture, despite the little dependence of the inherent cancer cell migration on the ECM condition. Specifically, cytoskeletal contractility-targeting drugs reduced migration speed in sparse gels, whereas migration in dense gels was retarded effectively by inhibiting proteolysis. The results corroborate the ability of cancer cells to switch their multiple invasion mechanisms depending on ECM condition, thus suggesting the importance of factoring in the biophysical properties of the ECM in anti-metastasis drug screenings.

  7. Cell-surface proteoglycan in sea urchin primary mesenchyme cell migration

    SciTech Connect

    Lane, M.C.

    1989-01-01

    Early in the development of the sea urchin embryo, the primary mesenchyme cells (PMC) migrate along the basal lamina of the blastocoel. Migration is inhibited in L. pictus embryos cultured in sulfate-free seawater and in S. purpuratus embryos exposed to exogenous {beta}-D-xylosides. An in vitro assay was developed to test the migratory capacity of normal PMC on normal and treated blastocoelic matrix. Sulfate deprivation and exposure to exogenous xyloside render PMC nonmotile on either matrix. Materials removed from the surface of normal PMC by treatment with 1 M urea restored migratory ability to defective cells, whereas a similar preparation isolated from the surface of epithelial cells at the same stage did not. Migration also resumed when cells were removed from the xyloside or returned to normal seawater. The urea extract was partially purified and characterized by radiolabeling, gel electrophoresis, fluorography, ion exchange chromatography, and western blotting. The PMC synthesize a large chondroitin sulfate/dermatan sulfate proteoglycan that is present in an active fraction isolated by chromatography. Chondroitinase ABC digestion of live cells blocked migration reversibly, further supporting the identification of the chondroitin sulfate/dermatan sulfate proteoglycan as the active component in the urea extract. Much of the incorporated sulfate was distributed along the filopodia in {sup 35}SO{sub 4}-labelled PMC by autoradiography. The morphology of normal and treated S. purpuratus PMC was examined by scanning electron microscopy, and differences in spreading, particularly of the extensive filopodia present on the cells, was observed. A model for the role of the chondroitin sulfate/dermatan sulfate proteoglycan in cell detachment during migration is proposed.

  8. Nonpolarized signaling reveals two distinct modes of 3D cell migration.

    PubMed

    Petrie, Ryan J; Gavara, Núria; Chadwick, Richard S; Yamada, Kenneth M

    2012-04-30

    We search in this paper for context-specific modes of three-dimensional (3D) cell migration using imaging for phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and active Rac1 and Cdc42 in primary fibroblasts migrating within different 3D environments. In 3D collagen, PIP3 and active Rac1 and Cdc42 were targeted to the leading edge, consistent with lamellipodia-based migration. In contrast, elongated cells migrating inside dermal explants and the cell-derived matrix (CDM) formed blunt, cylindrical protrusions, termed lobopodia, and Rac1, Cdc42, and PIP3 signaling was nonpolarized. Reducing RhoA, Rho-associated protein kinase (ROCK), or myosin II activity switched the cells to lamellipodia-based 3D migration. These modes of 3D migration were regulated by matrix physical properties. Specifically, experimentally modifying the elasticity of the CDM or collagen gels established that nonlinear elasticity supported lamellipodia-based migration, whereas linear elasticity switched cells to lobopodia-based migration. Thus, the relative polarization of intracellular signaling identifies two distinct modes of 3D cell migration governed intrinsically by RhoA, ROCK, and myosin II and extrinsically by the elastic behavior of the 3D extracellular matrix.

  9. Nonpolarized signaling reveals two distinct modes of 3D cell migration

    PubMed Central

    Gavara, Núria; Chadwick, Richard S.

    2012-01-01

    We search in this paper for context-specific modes of three-dimensional (3D) cell migration using imaging for phosphatidylinositol (3,4,5)-trisphosphate (PIP3) and active Rac1 and Cdc42 in primary fibroblasts migrating within different 3D environments. In 3D collagen, PIP3 and active Rac1 and Cdc42 were targeted to the leading edge, consistent with lamellipodia-based migration. In contrast, elongated cells migrating inside dermal explants and the cell-derived matrix (CDM) formed blunt, cylindrical protrusions, termed lobopodia, and Rac1, Cdc42, and PIP3 signaling was nonpolarized. Reducing RhoA, Rho-associated protein kinase (ROCK), or myosin II activity switched the cells to lamellipodia-based 3D migration. These modes of 3D migration were regulated by matrix physical properties. Specifically, experimentally modifying the elasticity of the CDM or collagen gels established that nonlinear elasticity supported lamellipodia-based migration, whereas linear elasticity switched cells to lobopodia-based migration. Thus, the relative polarization of intracellular signaling identifies two distinct modes of 3D cell migration governed intrinsically by RhoA, ROCK, and myosin II and extrinsically by the elastic behavior of the 3D extracellular matrix. PMID:22547408

  10. Girdin regulates the migration and invasion of glioma cells via the PI3K-Akt signaling pathway

    PubMed Central

    NI, WEIMIN; FANG, YAN; TONG, LEI; TONG, ZHAOXUE; YI, FUXIN; QIU, JIANWU; WANG, RUI; TONG, XIAOJIE

    2015-01-01

    Girdin, an actin-binding protein, is associated with cell migration and is expressed at high levels in glioma cells. However, the association between girdin and the development of glioma remains to be elucidated. In the present study, short-hairpin RNA technology was used to silence the gene expression of girdin. The effects of girdin silencing on glioma cell proliferation, migration and invasion were then assessed using a cell viability assay, wound-healing assay, transwell invasion assay, reverse transcription-quantitative polymerase chain reaction, western blot analysis and gelatin zymography. The results suggested that girdin silencing inhibited the proliferation, migration and invasion of glioma cells. In addition, the expression levels and activity of matrix metalloproteinase (MMP)-2 and MMP-9 were also affected by girdin silencing. Further mechanistic investigation indicated that girdin may regulate glioma cell migration and invasion through the phosphatidylinositol-3-kinase/protein kinase B (PI3K-Akt) signaling pathway. Therefore, the results of the present study provide a theoretical foundation for the development of anticancer drugs. PMID:26151295

  11. Overexpression of Rac1 in leukemia patients and its role in leukemia cell migration and growth

    SciTech Connect

    Wang, Jiying; Rao, Qing; Wang, Min; Wei, Hui; Xing, Haiyan; Liu, Hang; Wang, Yanzhong; Tang, Kejing; Peng, Leiwen; Tian, Zheng; Wang, Jianxiang

    2009-09-04

    Rac1 belongs to the Rho family that act as critical mediators of signaling pathways controlling cell migration and proliferation and contributes to the interactions of hematopoietic stem cells with their microenvironment. Alteration of Rac1 might result in unbalanced interactions and ultimately lead to leukemogenesis. In this study, we analyze the expression of Rac1 protein in leukemia patients and determine its role in the abnormal behaviours of leukemic cells. Rac1 protein is overexpressed in primary acute myeloid leukemia cells as compared to normal bone marrow mononuclear cells. siRNA-mediated silencing of Rac1 in leukemia cell lines induced inhibition of cell migration, proliferation, and colony formation. Additionally, blocking Rac1 activity by an inhibitor of Rac1-GTPase, NSC23766, suppressed cell migration and growth. We conclude that overexpression of Rac1 contributes to the accelerated migration and high proliferation potential of leukemia cells, which could be implicated in leukemia development and progression.

  12. Overexpression of Rac1 in leukemia patients and its role in leukemia cell migration and growth.

    PubMed

    Wang, Jiying; Rao, Qing; Wang, Min; Wei, Hui; Xing, Haiyan; Liu, Hang; Wang, Yanzhong; Tang, Kejing; Peng, Leiwen; Tian, Zheng; Wang, Jianxiang

    2009-09-01

    Rac1 belongs to the Rho family that act as critical mediators of signaling pathways controlling cell migration and proliferation and contributes to the interactions of hematopoietic stem cells with their microenvironment. Alteration of Rac1 might result in unbalanced interactions and ultimately lead to leukemogenesis. In this study, we analyze the expression of Rac1 protein in leukemia patients and determine its role in the abnormal behaviours of leukemic cells. Rac1 protein is overexpressed in primary acute myeloid leukemia cells as compared to normal bone marrow mononuclear cells. siRNA-mediated silencing of Rac1 in leukemia cell lines induced inhibition of cell migration, proliferation, and colony formation. Additionally, blocking Rac1 activity by an inhibitor of Rac1-GTPase, NSC23766, suppressed cell migration and growth. We conclude that overexpression of Rac1 contributes to the accelerated migration and high proliferation potential of leukemia cells, which could be implicated in leukemia development and progression.

  13. Human ether à-gogo K(+) channel 1 (hEag1) regulates MDA-MB-231 breast cancer cell migration through Orai1-dependent calcium entry.

    PubMed

    Hammadi, Mehdi; Chopin, Valérie; Matifat, Fabrice; Dhennin-Duthille, Isabelle; Chasseraud, Maud; Sevestre, Henri; Ouadid-Ahidouch, Halima

    2012-12-01

    Breast cancer (BC) has a poor prognosis due to its strong metastatic ability. Accumulating data present ether à go-go (hEag1) K(+) channels as relevant player in controlling cell cycle and proliferation of non-invasive BC cells. However, the role of hEag1 in invasive BC cells migration is still unknown. In this study, we studied both the functional expression and the involvement in cell migration of hEag1 in the highly metastatic MDA-MB-231 human BC cells. We showed that hEag1 mRNA and proteins were expressed in human invasive ductal carcinoma tissues and BC cell lines. Functional activity of hEag1 channels in MDA-MB-231 cells was confirmed using astemizole, a hEag1 blocker, or siRNA. Blocking or silencing hEag1 depolarized the membrane potential and reduced both Ca(2+) entry and MDA-MB-231 cell migration without affecting cell proliferation. Recent studies have reported that Ca(2+) entry through Orai1 channels is required for MDA-MB-231 cell migration. Down-regulation of hEag1 or Orai1 reduced Ca(2+) influx and cell migration with similar efficiency. Interestingly, no additive effects on Ca(2+) influx or cell migration were observed in cells co-transfected with sihEag1 and siOrai1. Finally, both Orai1 and hEag1 are expressed in invasive breast adenocarcinoma tissues and invaded metastatic lymph node samples (LNM(+)). In conclusion, this study is the first to demonstrate that hEag1 channels are involved in the serum-induced migration of BC cells by controlling the Ca(2+) entry through Orai1 channels. hEag1 may therefore represent a potential target for the suppression of BC cell migration, and thus prevention of metastasis development. PMID:22495877

  14. Human ether à-gogo K(+) channel 1 (hEag1) regulates MDA-MB-231 breast cancer cell migration through Orai1-dependent calcium entry.

    PubMed

    Hammadi, Mehdi; Chopin, Valérie; Matifat, Fabrice; Dhennin-Duthille, Isabelle; Chasseraud, Maud; Sevestre, Henri; Ouadid-Ahidouch, Halima

    2012-12-01

    Breast cancer (BC) has a poor prognosis due to its strong metastatic ability. Accumulating data present ether à go-go (hEag1) K(+) channels as relevant player in controlling cell cycle and proliferation of non-invasive BC cells. However, the role of hEag1 in invasive BC cells migration is still unknown. In this study, we studied both the functional expression and the involvement in cell migration of hEag1 in the highly metastatic MDA-MB-231 human BC cells. We showed that hEag1 mRNA and proteins were expressed in human invasive ductal carcinoma tissues and BC cell lines. Functional activity of hEag1 channels in MDA-MB-231 cells was confirmed using astemizole, a hEag1 blocker, or siRNA. Blocking or silencing hEag1 depolarized the membrane potential and reduced both Ca(2+) entry and MDA-MB-231 cell migration without affecting cell proliferation. Recent studies have reported that Ca(2+) entry through Orai1 channels is required for MDA-MB-231 cell migration. Down-regulation of hEag1 or Orai1 reduced Ca(2+) influx and cell migration with similar efficiency. Interestingly, no additive effects on Ca(2+) influx or cell migration were observed in cells co-transfected with sihEag1 and siOrai1. Finally, both Orai1 and hEag1 are expressed in invasive breast adenocarcinoma tissues and invaded metastatic lymph node samples (LNM(+)). In conclusion, this study is the first to demonstrate that hEag1 channels are involved in the serum-induced migration of BC cells by controlling the Ca(2+) entry through Orai1 channels. hEag1 may therefore represent a potential target for the suppression of BC cell migration, and thus prevention of metastasis development.

  15. Cefazolin Irreversibly Inhibits Proliferation and Migration of Human Mesenchymal Stromal Cells

    PubMed Central

    Pilge, Hakan; Fröbel, Julia; Lensing-Höhn, Sabine; Zilkens, Christoph; Krauspe, Rüdiger

    2016-01-01

    Drugs may have a significant effect on postoperative bone healing by reducing the function of human mesenchymal stromal cells (hMSC) or mature osteoblasts. Although cefazolin is one of the most commonly used antibiotic drugs in arthroplasty to prevent infection worldwide, there is a lack of information regarding how cefazolin affects hMSC and therefore may have an effect on early bone healing. We studied the proliferation and migration capacity of primary hMSC during cefazolin treatment at various doses for up to 3 days, as well as the reversibility of the effects during the subsequent 3 days of culture without the drug. We found a time- and dose-dependent reduction of the proliferation rate and the migratory potential. Tests of whether these effects were reversible revealed that doses ≥250 μg/mL or treatments longer than 24 h irreversibly affected the cells. We are the first to show that application of cefazolin irreversibly inhibits the potential of hMSC for migration to the trauma site and local proliferation. Cefazolin should be administered only at the required dosage and time to prevent periprosthetic infection. If long-term administration is required and delayed bone healing is present, cefazolin application must be considered as a cause of delayed bone healing. PMID:27069918

  16. Random migration precedes stable target cell interactions of tumor-infiltrating T cells.

    PubMed

    Mrass, Paulus; Takano, Hajime; Ng, Lai Guan; Daxini, Sachin; Lasaro, Marcio O; Iparraguirre, Amaya; Cavanagh, Lois L; von Andrian, Ulrich H; Ertl, Hildegund C J; Haydon, Philip G; Weninger, Wolfgang

    2006-11-27

    The tumor microenvironment is composed of an intricate mixture of tumor and host-derived cells that engage in a continuous interplay. T cells are particularly important in this context as they may recognize tumor-associated antigens and induce tumor regression. However, the precise identity of cells targeted by tumor-infiltrating T lymphocytes (TILs) as well as the kinetics and anatomy of TIL-target cell interactions within tumors are incompletely understood. Furthermore, the spatiotemporal conditions of TIL locomotion through the tumor stroma, as a prerequisite for establishing contact with target cells, have not been analyzed. These shortcomings limit the rational design of immunotherapeutic strategies that aim to overcome tumor-immune evasion. We have used two-photon microscopy to determine, in a dynamic manner, the requirements leading to tumor regression by TILs. Key observations were that TILs migrated randomly throughout the tumor microenvironment and that, in the absence of cognate antigen, they were incapable of sustaining active migration. Furthermore, TILs in regressing tumors formed long-lasting (>or=30 min), cognate antigen-dependent contacts with tumor cells. Finally, TILs physically interacted with macrophages, suggesting tumor antigen cross-presentation by these cells. Our results demonstrate that recognition of cognate antigen within tumors is a critical determinant of optimal TIL migration and target cell interactions, and argue against TIL guidance by long-range chemokine gradients.

  17. Ectopic Cerebellar Cell Migration Causes Maldevelopment of Purkinje Cells and Abnormal Motor Behaviour in Cxcr4 Null Mice

    PubMed Central

    Huang, Guo-Jen; Edwards, Andrew; Tsai, Cheng-Yu; Lee, Yi-Shin; Peng, Lei; Era, Takumi; Hirabayashi, Yoshio; Tsai, Ching-Yen; Nishikawa, Shin-Ichi; Iwakura, Yoichiro; Chen, Shu-Jen; Flint, Jonathan

    2014-01-01

    SDF-1/CXCR4 signalling plays an important role in neuronal cell migration and brain development. However, the impact of CXCR4 deficiency in the postnatal mouse brain is still poorly understood. Here, we demonstrate the importance of CXCR4 on cerebellar development and motor behaviour by conditional inactivation of Cxcr4 in the central nervous system. We found CXCR4 plays a key role in cerebellar development. Its loss leads to defects in Purkinje cell dentritogenesis and axonal projection in vivo but not in cell culture. Transcriptome analysis revealed the most significantly affected pathways in the Cxcr4 deficient developing cerebellum are involved in extra cellular matrix receptor interactions and focal adhesion. Consistent with functional impairment of the cerebellum, Cxcr4 knockout mice have poor coordination and balance performance in skilled motor tests. Together, these results suggest ectopic the migration of granule cells impairs development of Purkinje cells, causes gross cerebellar anatomical disruption and leads to behavioural motor defects in Cxcr4 null mice. PMID:24516532

  18. Transfection microarrays for high-throughput phenotypic screening of genes involved in cell migration.

    PubMed

    Onuki-Nagasaki, Reiko; Nagasaki, Akira; Hakamada, Kazumi; Uyeda, Taro Q P; Fujita, Satoshi; Miyake, Masato; Miyake, Jun

    2010-01-01

    Cell migration is important in several biological phenomena, such as cancer metastasis. Therefore, the identification of genes involved in cell migration might facilitate the discovery of antimetastatic drugs. However, screening of genes by the current methods can be complicated by factors related to cell stimulation, for example, abolition of contact inhibition and the release inflammatory cytokines from wounded cells during examinations of wound healing in vitro. To overcome these problems and identify genes involved in cell migration, in this chapter we describe the use of transfection microarrays for high-throughput phenotypic screening. PMID:20387151

  19. A novel role for Lh3 dependent ECM modifications during neural crest cell migration in zebrafish.

    PubMed

    Banerjee, Santanu; Isaacman-Beck, Jesse; Schneider, Valerie A; Granato, Michael

    2013-01-01

    During vertebrate development, trunk neural crest cells delaminate along the entire length of the dorsal neural tube and initially migrate as a non-segmented sheet. As they enter the somites, neural crest cells rearrange into spatially restricted segmental streams. Extracellular matrix components are likely to play critical roles in this transition from a sheet-like to a stream-like mode of migration, yet the extracellular matrix components and their modifying enzymes critical for this transition are largely unknown. Here, we identified the glycosyltransferase Lh3, known to modify extracellular matrix components, and its presumptive substrate Collagen18A1, to provide extrinsic signals critical for neural crest cells to transition from a sheet-like migration behavior to migrating as a segmental stream. Using live cell imaging we show that in lh3 null mutants, neural crest cells fail to transition from a sheet to a stream, and that they consequently enter the somites as multiple streams, or stall shortly after entering the somites. Moreover, we demonstrate that transgenic expression of lh3 in a small subset of somitic cells adjacent to where neural crest cells switch from sheet to stream migration restores segmental neural crest cell migration. Finally, we show that knockdown of the presumptive Lh3 substrate Collagen18A1 recapitulates the neural crest cell migration defects observed in lh3 mutants, consistent with the notion that Lh3 exerts its effect on neural crest cell migration by regulating post-translational modifications of Collagen18A1. Together these data suggest that Lh3-Collagen18A1 dependent ECM modifications regulate the transition of trunk neural crest cells from a non-segmental sheet like migration mode to a segmental stream migration mode.

  20. Kinetic stabilization of microtubule dynamics by indanocine perturbs EB1 localization, induces defects in cell polarity and inhibits migration of MDA-MB-231 cells.

    PubMed

    Kapoor, Sonia; Panda, Dulal

    2012-06-01

    Cell motility is an essential aspect of metastatic spread of cancer. Microtubule-targeted agents exhibit anti-metastatic properties, the underlying mechanism of which remains understudied. In this study, we have investigated the role of microtubule dynamics in migration of cancer cells using indanocine, a synthetic small molecule inhibitor of tubulin. We found that indanocine, at concentrations that did not visibly affect microtubule organization, suppressed dynamic instability of microtubules and reduced the rate of migration of highly metastatic MDA-MB-231 cells. Indanocine-treated cells were defective in lamellipodium formation and could not develop polarized morphology. The kinetic stabilization of microtubules was associated with a marked increase in their acetylation level and a perturbation in the localization of EB1, a microtubule plus end binding protein. Using standard scratch wound healing assay and immunofluorescence analysis; we found that microtubule acetylation occurred in the direction of migration in vehicle-treated cells, whereas indanocine treatment led to a global acetylation of microtubules. The results together suggested that selective stabilization of microtubules was perturbed in the presence of indanocine that possibly resulted in lack of cell polarization and a concurrent reduction in migration of cells. Moreover, microtubule stabilization by indanocine affected adhesion turnover and impaired the polarized pattern of adhesion sites in cells. Together the results indicated that the regulation of microtubule dynamics is required to coordinate cell polarization as well as adhesion asymmetry and support the hypothesis that the perturbation of microtubule dynamics by tubulin-targeted agents can be exploited to restrict the migration of tumor cells.

  1. Common mechanisms linking connexin43 to neural progenitor cell migration and glioma invasion.

    PubMed

    Naus, Christian C; Aftab, Qurratulain; Sin, Wun Chey

    2016-02-01

    Cell migration is critical for cell differentiation, tissue formation and organ development. Several mechanisms come to play in the process of cell migration, orchestrating changes in cell polarity, adhesion, process extension and motility. Recent findings have shown that gap junctions, and specifically connexin43 (Cx43), can play a significant role in these processes, impacting adhesion and cytoskeletal rearrangements. Thus Cx43 within a cell regulates its motility and migration via intracellular signaling. Furthermore, Cx43 in the host cells can impact the degree of cellular migration through that tissue. Similarities in these connexin-based processes account for both neural progenitor migration in the developing brain, and for glioma cell invasion in the mature brain. In both cases, Cx43 in the tissue ("soil") in which cells ("seeds") exist facilitates their migration and, for glioma cells, tissue invasion. Cx43 mediates these effects through channel- and non-channel-dependent mechanisms which have similarities in both paradigms of cell migration. This provides insight into developmental processes and pathological situations, as well as possible therapeutic approaches regarding specific functional domains of gap junction proteins.

  2. ALDH isozymes downregulation affects cell growth, cell motility and gene expression in lung cancer cells

    PubMed Central

    Moreb, Jan S; Baker, Henry V; Chang, Lung-Ji; Amaya, Maria; Lopez, M Cecilia; Ostmark, Blanca; Chou, Wayne

    2008-01-01

    Background Aldehyde dehydrogenase isozymes ALDH1A1 and ALDH3A1 are highly expressed in non small cell lung cancer. Neither the mechanisms nor the biologic significance for such over expression have been studied. Methods We have employed oligonucleotide microarrays to analyze changes in gene profiles in A549 lung cancer cell line in which ALDH activity was reduced by up to 95% using lentiviral mediated expression of siRNA against both isozymes (Lenti 1+3). Stringent analysis methods were used to identify gene expression patterns that are specific to the knock down of ALDH activity and significantly different in comparison to wild type A549 cells (WT) or cells similarly transduced with green fluorescent protein (GFP) siRNA. Results We confirmed significant and specific down regulation of ALDH1A1 and ALDH3A1 in Lenti 1+3 cells and in comparison to 12 other ALDH genes detected. The results of the microarray analysis were validated by real time RT-PCR on RNA obtained from Lenti 1+3 or WT cells treated with ALDH activity inhibitors. Detailed functional analysis was performed on 101 genes that were significantly different (P < 0.001) and their expression changed by ≥ 2 folds in the Lenti 1+3 group versus the control groups. There were 75 down regulated and 26 up regulated genes. Protein binding, organ development, signal transduction, transcription, lipid metabolism, and cell migration and adhesion were among the most affected pathways. Conclusion These molecular effects of the ALDH knock-down are associated with in vitro functional changes in the proliferation and motility of these cells and demonstrate the significance of ALDH enzymes in cell homeostasis with a potentially significant impact on the treatment of lung cancer. PMID:19025616

  3. Lipid raft association restricts CD44-ezrin interaction and promotion of breast cancer cell migration.

    PubMed

    Donatello, Simona; Babina, Irina S; Hazelwood, Lee D; Hill, Arnold D K; Nabi, Ivan R; Hopkins, Ann M

    2012-12-01

    Cancer cell migration is an early event in metastasis, the main cause of breast cancer-related deaths. Cholesterol-enriched membrane domains called lipid rafts influence the function of many molecules, including the raft-associated protein CD44. We describe a novel mechanism whereby rafts regulate interactions between CD44 and its binding partner ezrin in migrating breast cancer cells. Specifically, in nonmigrating cells, CD44 and ezrin localized to different membranous compartments: CD44 predominantly in rafts, and ezrin in nonraft compartments. After the induction of migration (either nonspecific or CD44-driven), CD44 affiliation with lipid rafts was decreased. This was accompanied by increased coprecipitation of CD44 and active (threonine-phosphorylated) ezrin-radixin-moesin (ERM) proteins in nonraft compartments and increased colocalization of CD44 with the nonraft protein, transferrin receptor. Pharmacological raft disruption using methyl-β-cyclodextrin also increased CD44-ezrin coprecipitation and colocalization, further suggesting that CD44 interacts with ezrin outside rafts during migration. Conversely, promoting CD44 retention inside lipid rafts by pharmacological inhibition of depalmitoylation virtually abolished CD44-ezrin interactions. However, transient single or double knockdown of flotillin-1 or caveolin-1 was not sufficient to increase cell migration over a short time course, suggesting complex crosstalk mechanisms. We propose a new model for CD44-dependent breast cancer cell migration, where CD44 must relocalize outside lipid rafts to drive cell migration. This could have implications for rafts as pharmacological targets to down-regulate cancer cell migration.

  4. PLEKHG3 enhances polarized cell migration by activating actin filaments at the cell front.

    PubMed

    Nguyen, Trang Thi Thu; Park, Wei Sun; Park, Byung Ouk; Kim, Cha Yeon; Oh, Yohan; Kim, Jin Man; Choi, Hana; Kyung, Taeyoon; Kim, Cheol-Hee; Lee, Gabsang; Hahn, Klaus M; Meyer, Tobias; Heo, Won Do

    2016-09-01

    Cells migrate by directing Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) activities and by polymerizing actin toward the leading edge of the cell. Previous studies have proposed that this polarization process requires a local positive feedback in the leading edge involving Rac small GTPase and actin polymerization with PI3K likely playing a coordinating role. Here, we show that the pleckstrin homology and RhoGEF domain containing G3 (PLEKHG3) is a PI3K-regulated Rho guanine nucleotide exchange factor (RhoGEF) for Rac1 and Cdc42 that selectively binds to newly polymerized actin at the leading edge of migrating fibroblasts. Optogenetic inactivation of PLEKHG3 showed that PLEKHG3 is indispensable both for inducing and for maintaining cell polarity. By selectively binding to newly polymerized actin, PLEKHG3 promotes local Rac1/Cdc42 activation to induce more local actin polymerization, which in turn promotes the recruitment of more PLEKHG3 to induce and maintain cell front. Thus, autocatalytic reinforcement of PLEKHG3 localization to the leading edge of the cell provides a molecular basis for the proposed positive feedback loop that is required for cell polarization and directed migration. PMID:27555588

  5. PLEKHG3 enhances polarized cell migration by activating actin filaments at the cell front

    PubMed Central

    Nguyen, Trang Thi Thu; Park, Wei Sun; Park, Byung Ouk; Kim, Cha Yeon; Oh, Yohan; Kim, Jin Man; Choi, Hana; Kyung, Taeyoon; Kim, Cheol-Hee; Lee, Gabsang; Hahn, Klaus M.; Meyer, Tobias; Heo, Won Do

    2016-01-01

    Cells migrate by directing Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) activities and by polymerizing actin toward the leading edge of the cell. Previous studies have proposed that this polarization process requires a local positive feedback in the leading edge involving Rac small GTPase and actin polymerization with PI3K likely playing a coordinating role. Here, we show that the pleckstrin homology and RhoGEF domain containing G3 (PLEKHG3) is a PI3K-regulated Rho guanine nucleotide exchange factor (RhoGEF) for Rac1 and Cdc42 that selectively binds to newly polymerized actin at the leading edge of migrating fibroblasts. Optogenetic inactivation of PLEKHG3 showed that PLEKHG3 is indispensable both for inducing and for maintaining cell polarity. By selectively binding to newly polymerized actin, PLEKHG3 promotes local Rac1/Cdc42 activation to induce more local actin polymerization, which in turn promotes the recruitment of more PLEKHG3 to induce and maintain cell front. Thus, autocatalytic reinforcement of PLEKHG3 localization to the leading edge of the cell provides a molecular basis for the proposed positive feedback loop that is required for cell polarization and directed migration. PMID:27555588

  6. Overexpression of S-adenosylhomocysteine hydrolase (SAHH) in esophageal squamous cell carcinoma (ESCC) cell lines: effects on apoptosis, migration and adhesion of cells.

    PubMed

    Li, Qinghua; Mao, Lihong; Wang, Ruili; Zhu, Liqiang; Xue, Lexun

    2014-01-01

    S-adenosylhomocysteine hydrolase (SAHH) is the sole enzyme that catalyses the hydrolysis of S-adenosylhomocysteine (SAH) in methylation reaction. Previous studies have shown that its inhibition or deficiency leads to several human disorders such as severe coagulopathy, hepatopathy and myopathy. However, the effects of SAHH on esophageal squamous cell carcinoma (ESCC) cells have not been explored so far. To determine whether SAHH is involved in carcinogenesis of the esophagus, we investigated the expression of SAHH in ESCC and normal esophageal epithelial cells and found that SAHH was downregulated in ESCC cells compared with normal esophageal epithelial cells (P < 0.05). The overexpressed SAHH in ESCC cells promoted cell apoptosis, inhibited cell migration and adhesion, but did not affect the cell proliferation and cell cycle. Furthermore, an interaction of SAHH with receptor of activated C kinase 1 (RACK1) protein was detected by coimmunoprecipitation and an increased RACK1, which is caused by overexpression of SAHH, was verified by Western blotting. The findings mentioned above demonstrate that SAHH can promote apoptosis, inhibit migration and adhesion of ESCC cells suggesting that it may be involved in carcinogenesis of the esophagus.

  7. Expression of complete keratin filaments in mouse L cells augments cell migration and invasion.

    PubMed Central

    Chu, Y W; Runyan, R B; Oshima, R G; Hendrix, M J

    1993-01-01

    Intermediate filament proteins have been used to diagnose the origin of specific cells. Classically, vimentin is found in mesenchymal cells, and keratins are present in epithelial cells. However, recent evidence suggests that the coexpression of these phenotype-specific proteins augments tumor cell motility, and hence, metastasis. In the present study, we used the mouse L-cell model to determine if a direct correlation exists between the expression of additional keratins in these cells, which normally express only vimentin, and their migratory ability. Mouse L cells were transfected with human keratins 8, 18, and both 8 and 18. The results indicate that the cells expressing complete keratin filaments have a higher migratory and invasive ability (through extracellular matrix-coated filters) compared with the parental and control-transfected clones. Furthermore, there is an enrichment of keratin-positive cells from a heterogeneous population of L clones selected over serial migrations. This migratory activity was directly correlated with the spreading ability of the cells on Matrigel matrix, in which the keratin-positive transfectants maintain a round morphology for a longer duration, compared with the other L-cell populations. Collectively, these data suggest that keratins may play an important role(s) in migration, through a special interaction with the extracellular environment, thereby influencing cell shape. Images Fig. 1 Fig. 4 PMID:7683431

  8. Tamarind Seed Xyloglucans Promote Proliferation and Migration of Human Skin Cells through Internalization via Stimulation of Proproliferative Signal Transduction Pathways.

    PubMed

    Nie, W; Deters, A M

    2013-01-01

    Xyloglucans (XGs) of Tamarindus indica L. Fabaceae are used as drug vehicles or as ingredients of cosmetics. Two xyloglucans were extracted from T. indica seed with cold water (TSw) and copper complex precipitation (TSc). Both were analyzed in regard to composition and influence on cell viability, proliferation, cell cycle progression, migration, MAPK phosphorylation, and gene expression of human skin keratinocytes (NHEK and HaCaT) and fibroblasts (NHDF) in vitro. TSw and TSc differed in molecular weight, rhamnose content, and ratios of xylose, arabinose, galactose, and glucose. Both XGs improved keratinocytes and fibroblast proliferation, promoted the cell cycle, and stimulated migration and intracellular enzyme activity of NHDF after endosomal uptake. Only TSw significantly enhanced HaCaT migration and extracellular enzyme activity of NHDF and HaCaT. TSw and TSc predominantly enhanced the phosphorylation of molecules that referred to Erk signaling in NHEK. In NHDF parts of the integrin signaling and SAPK/JNK pathway were affected. Independent of cell type TSw marginally regulated the expression of genes, which referred to membrane proteins, cytoskeleton, cytokine signaling, and ECM as well as to processes of metabolism and transcription. Results show that T. indica xyloglucans promote skin regeneration by a direct influence on cell proliferation and migration.

  9. Tamarind Seed Xyloglucans Promote Proliferation and Migration of Human Skin Cells through Internalization via Stimulation of Proproliferative Signal Transduction Pathways.

    PubMed

    Nie, W; Deters, A M

    2013-01-01

    Xyloglucans (XGs) of Tamarindus indica L. Fabaceae are used as drug vehicles or as ingredients of cosmetics. Two xyloglucans were extracted from T. indica seed with cold water (TSw) and copper complex precipitation (TSc). Both were analyzed in regard to composition and influence on cell viability, proliferation, cell cycle progression, migration, MAPK phosphorylation, and gene expression of human skin keratinocytes (NHEK and HaCaT) and fibroblasts (NHDF) in vitro. TSw and TSc differed in molecular weight, rhamnose content, and ratios of xylose, arabinose, galactose, and glucose. Both XGs improved keratinocytes and fibroblast proliferation, promoted the cell cycle, and stimulated migration and intracellular enzyme activity of NHDF after endosomal uptake. Only TSw significantly enhanced HaCaT migration and extracellular enzyme activity of NHDF and HaCaT. TSw and TSc predominantly enhanced the phosphorylation of molecules that referred to Erk signaling in NHEK. In NHDF parts of the integrin signaling and SAPK/JNK pathway were affected. Independent of cell type TSw marginally regulated the expression of genes, which referred to membrane proteins, cytoskeleton, cytokine signaling, and ECM as well as to processes of metabolism and transcription. Results show that T. indica xyloglucans promote skin regeneration by a direct influence on cell proliferation and migration. PMID:24106497

  10. Tamarind Seed Xyloglucans Promote Proliferation and Migration of Human Skin Cells through Internalization via Stimulation of Proproliferative Signal Transduction Pathways

    PubMed Central

    Nie, W.; Deters, A. M.

    2013-01-01

    Xyloglucans (XGs) of Tamarindus indica L. Fabaceae are used as drug vehicles or as ingredients of cosmetics. Two xyloglucans were extracted from T. indica seed with cold water (TSw) and copper complex precipitation (TSc). Both were analyzed in regard to composition and influence on cell viability, proliferation, cell cycle progression, migration, MAPK phosphorylation, and gene expression of human skin keratinocytes (NHEK and HaCaT) and fibroblasts (NHDF) in vitro. TSw and TSc differed in molecular weight, rhamnose content, and ratios of xylose, arabinose, galactose, and glucose. Both XGs improved keratinocytes and fibroblast proliferation, promoted the cell cycle, and stimulated migration and intracellular enzyme activity of NHDF after endosomal uptake. Only TSw significantly enhanced HaCaT migration and extracellular enzyme activity of NHDF and HaCaT. TSw and TSc predominantly enhanced the phosphorylation of molecules that referred to Erk signaling in NHEK. In NHDF parts of the integrin signaling and SAPK/JNK pathway were affected. Independent of cell type TSw marginally regulated the expression of genes, which referred to membrane proteins, cytoskeleton, cytokine signaling, and ECM as well as to processes of metabolism and transcription. Results show that T. indica xyloglucans promote skin regeneration by a direct influence on cell proliferation and migration. PMID:24106497

  11. Impact of Mesenchymal Stem Cell secreted PAI-1 on colon cancer cell migration and proliferation

    SciTech Connect

    Hogan, Niamh M.; Joyce, Myles R.; Murphy, J. Mary; Barry, Frank P.; O’Brien, Timothy; Kerin, Michael J.; Dwyer, Roisin M.

    2013-06-14

    Highlights: •MSCs were directly co-cultured with colorectal cancer (CRC) cells on 3D scaffolds. •MSCs influence CRC protein/gene expression, proliferation and migration. •We report a significant functional role of MSC-secreted PAI-1 in colon cancer. -- Abstract: Mesenchymal Stem Cells are known to engraft and integrate into the architecture of colorectal tumours, with little known regarding their fate following engraftment. This study aimed to investigate mediators of Mesenchymal Stem Cell (MSC) and colon cancer cell (CCC) interactions. Mesenchymal Stem Cells and colon cancer cells (HT29 and HCT-116) were cultured individually or in co-culture on 3-dimensional scaffolds. Conditioned media containing all secreted factors was harvested at day 1, 3 and 7. Chemokine secretion and expression were analyzed by Chemi-array, ELISA (Macrophage migration inhibitory factor (MIF), plasminogen activator inhibitor type 1 (PAI-1)) and RQ-PCR. Colon cancer cell migration and proliferation in response to recombinant PAI-1, MSCs and MSCs + antibody to PAI-1 was analyzed using Transwell inserts and an MTS proliferation assay respectively. Chemi-array revealed secretion of a wide range of factors by each cell population, including PAI-1and MIF. ELISA analysis revealed Mesenchymal Stem Cells to secrete the highest levels of PAI-1 (MSC mean 10.6 ng/mL, CCC mean 1.01 ng/mL), while colon cancer cells were the principal source of MIF. MSC-secreted PAI-1 stimulated significant migration of both CCC lines, with an antibody to the chemokine shown to block this effect (67–88% blocking,). A cell-line dependant effect on CCC proliferation was shown for Mesenchymal Stem Cell-secreted PAI-1 with HCT-116 cells showing decreased proliferation at all concentrations, and HT29 cells showing increased proliferation in the presence of higher PAI-1 levels. This is the first study to identify PAI-1 as an important mediator of Mesenchymal Stem Cell/colon cancer cell interactions and highlights the

  12. Dexamethasone Inhibits TGF-β1–Induced Cell Migration by Regulating the ERK and AKT Pathways in Human Colon Cancer Cells Via CYR61

    PubMed Central

    Han, Sanghoon; Bui, Ngoc Thuy; Ho, Manh Tin; Kim, Young Mee; Cho, Moonjae; Shin, Dong Bok

    2016-01-01

    Purpose One of the features in cancer development is the migration of cancer cells to form metastatic lesions. CYR61 protein promotes migration and the epithelial-mesenchymal transition in several cancer cell types. Evidence suggests that CYR61 and dexamethasone are relevant to colorectal cancer. However, relationships between them and colorectal cancer are still unclear. Understanding the molecular mechanism of colorectal cancer progression related with CYR61 and dexamethasone, which is widely used for combination chemotherapy, is necessary for improved therapy. Materials and Methods We used colorectal cancer cells, HCT116, co-treated with transforming growth factor β1 (TGF-β1) and dexamethasone to examine the inhibitory migration effect of dexamethasone by migratory assay. Alternatively, both migratory pathways, expression of AKT and ERK, and the target factor CYR61 was also tested by co-treatment with TGF-β1 and dexamethasone. Results We report that dexamethasone significantly inhibited TGF-β1–induced cell migration, without affecting cell proliferation. Importantly, we observed that TGF-β1 promoted the epithelial-mesenchymal transition process and that dexamethasone co-treatment abolished this effect. ERK and AKT signaling pathways were found to mediate TGF-β1–induced migration, which was inhibited by dexamethasone. In addition, TGF-β1 treatment induced CYR61 expression whereas dexamethasone reduced it. These observations were compatible with the modulation of migration observed following treatment of HCT116 cells with human recombinant CYR61 and anti-CYR61 antibody. Our results also indicated that TGF-β1 enhanced collagen I and reduced matrix metalloproteinase 1 expression, which was reversed by dexamethasone treatment. Conclusion These findings suggested that dexamethasone inhibits AKT and ERK phosphorylation, leading to decreased CYR61 expression, which in turn blocks TGF-β1–induced migration. PMID:26693911

  13. Leishmania major lipophosphoglycan modulates the phenotype and inhibits migration of murine Langerhans cells

    PubMed Central

    Ponte-Sucre, Alicia; Heise, Dirk; Moll, Heidrun

    2001-01-01

    Langerhans cells (LC), members of the dendritic cell family, play a central role in the initiation and regulation of the immune response against the protozoan parasite Leishmania major. LC take up antigens in the skin and transport them to the regional lymph nodes for presentation to T cells. However, it is not known whether LC functions are modulated by parasite antigens. In the present study, we examined the effect of a major parasite surface molecule, L. major lipophosphoglycan (LPG), on the maturation of LC and their migratory properties. The results show that exposure to LPG did not affect the expression of major histocompatibility complex (MHC) class II and B7, but induced an up-regulation of CD25, CD31 and vascular endothelial (VE)-cadherin expression and a down-regulation of Mac-1 expression, by LC. Importantly, LPG treatment inhibited the migratory activity of LC, as it reduced their efflux from skin explants and their migration in transwell cultures. These results suggest that Leishmania LPG impairs LC migration out of the skin and thus may modulate their immunostimulatory functions, which require LC translocation from skin to lymph nodes. PMID:11899433

  14. Trypsinogen 4 boosts tumor endothelial cells migration through proteolysis of tissue factor pathway inhibitor-2.

    PubMed

    Ghilardi, Carmen; Silini, Antonietta; Figini, Sara; Anastasia, Alessia; Lupi, Monica; Fruscio, Robert; Giavazzi, Raffaella; Bani, Maria Rosa

    2015-09-29

    Proteases contribute to cancer in many ways, including tumor vascularization and metastasis, and their pharmacological inhibition is a potential anticancer strategy. We report that human endothelial cells (EC) express the trypsinogen 4 isoform of the serine protease 3 (PRSS3), and lack both PRSS2 and PRSS1. Trypsinogen 4 expression was upregulated by the combined action of VEGF-A, FGF-2 and EGF, angiogenic factors representative of the tumor microenvironment. Suppression of trypsinogen 4 expression by siRNA inhibited the angiogenic milieu-induced migration of EC from cancer specimens (tumor-EC), but did not affect EC from normal tissues. We identified tissue factor pathway inhibitor-2 (TFPI-2), a matrix associated inhibitor of cell motility, as the functional target of trypsinogen 4, which cleaved TFPI-2 and removed it from the matrix put down by tumor-EC. Silencing tumor-EC for trypsinogen 4 accumulated TFPI2 in the matrix. Showing that angiogenic factors stimulate trypsinogen 4 expression, which hydrolyses TFPI-2 favoring a pro-migratory situation, our study suggests a new pathway linking tumor microenvironment signals to endothelial cell migration, which is essential for angiogenesis and blood vessel remodeling. Abolishing trypsinogen 4 functions might be an exploitable strategy as anticancer, particularly anti-vascular, therapy. PMID:26318044

  15. Formation of hyaluronan- and versican-rich pericellular matrix is required for proliferation and migration of vascular smooth muscle cells.

    PubMed

    Evanko, S P; Angello, J C; Wight, T N

    1999-04-01

    The accumulation of hyaluronan (HA) and the HA-binding proteoglycan versican around smooth muscle cells in lesions of atherosclerosis suggests that together these molecules play an important role in the events of atherogenesis. In this study we have examined the formation of HA- and versican-rich pericellular matrices by human aortic smooth muscle cells in vitro, using a particle-exclusion assay, and the role of the pericellular matrix in cell proliferation and migration. The structural dependence of the pericellular matrix on HA can be demonstrated by the