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Sample records for affects cell migration

  1. Genistein affects proliferation and migration of bovine oviductal epithelial cells.

    PubMed

    García, Daniela C; Valdecantos, Pablo A; Miceli, Dora C; Roldán-Olarte, Mariela

    2017-03-08

    Genistein is one of the most abundant isoflavones in soybean. This molecule induces cell cycle arrest and apoptosis in different normal and cancer cells. Genistein has been of considerable interest due to its adverse effects on bovine reproduction, altering estrous cycle, implantation and fetal development and producing subfertility or infertility. The objective of this work was to study the effects of genistein on the expression of selected genes involved in the regulation of cell cycle and apoptosis. Primary cultures of bovine oviductal epithelial cells (BOEC) were treated with different genistein concentrations (0.2, 2 and 10μM) to analyze CYCLIN B1, BCL-2 and BAX gene expression by Real-time RT-PCR. Results showed that genistein down-regulated CYCLIN B1 expression, affecting cell cycle progression, and caused a decrease in the BCL-2/BAX ratio starting at 2μM of genistein. In addition, in order to determine if genistein affects BOEC migration, in vitro wound healing assays were performed. A significant reduction in cell migration after 12h of culture was observed at both 0.2 and 10μM genistein concentrations. Also, in the presence of genistein the percentage of mitotic cells decreased, although apoptotic cells percentages were not affected. These findings indicate that genistein has an inhibitory effect on BOEC proliferation and migration, suggesting that it could influence the normal physiology of the oviductal epithelium.

  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. 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.

  5. 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

  6. 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

  7. Factors affecting directional migration of bone marrow mesenchymal stem cells to the injured spinal cord.

    PubMed

    Xia, Peng; Pan, Su; Cheng, Jieping; Yang, Maoguang; Qi, Zhiping; Hou, Tingting; Yang, Xiaoyu

    2014-09-15

    Microtubule-associated protein 1B plays an important role in axon guidance and neuronal migration. In the present study, we sought to discover the mechanisms underlying microtubule-associated protein 1B mediation of axon guidance and neuronal migration. We exposed bone marrow mesenchymal stem cells to okadaic acid or N-acetyl-D-erythro-sphingosine (an inhibitor and stimulator, respectively, of protein phosphatase 2A) for 24 hours. The expression of the phosphorylated form of type I microtubule-associated protein 1B in the cells was greater after exposure to okadaic acid and lower after N-acetyl-D-erythro-sphingosine. We then injected the bone marrow mesenchymal stem cells through the ear vein into rabbit models of spinal cord contusion. The migration of bone marrow mesenchymal stem cells towards the injured spinal cord was poorer in cells exposed to okadaic acid- and N-acetyl-D-erythro-sphingosine than in non-treated bone marrow mesenchymal stem cells. Finally, we blocked phosphatidylinositol 3-kinase (PI3K) and extracellular signal-regulated kinase 1/2 (ERK1/2) pathways in rabbit bone marrow mesenchymal stem cells using the inhibitors LY294002 and U0126, respectively. LY294002 resulted in an elevated expression of phosphorylated type I microtubule-associated protein 1B, whereas U0126 caused a reduction in expression. The present data indicate that PI3K and ERK1/2 in bone marrow mesenchymal stem cells modulate the phosphorylation of microtubule-associated protein 1B via a cross-signaling network, and affect the migratory efficiency of bone marrow mesenchymal stem cells towards injured spinal cord.

  8. Analysing immune cell migration.

    PubMed

    Beltman, Joost B; Marée, Athanasius F M; de Boer, Rob J

    2009-11-01

    The visualization of the dynamic behaviour of and interactions between immune cells using time-lapse video microscopy has an important role in modern immunology. To draw robust conclusions, quantification of such cell migration is required. However, imaging experiments are associated with various artefacts that can affect the estimated positions of the immune cells under analysis, which form the basis of any subsequent analysis. Here, we describe potential artefacts that could affect the interpretation of data sets on immune cell migration. We propose how these errors can be recognized and corrected, and suggest ways to prevent the data analysis itself leading to biased results.

  9. Ageing Adversely Affects the Migration and Function of Marginal Zone B Cells.

    PubMed

    Turner, Vivian M; Mabbott, Neil A

    2017-04-02

    Marginal zone (MZ) B cells are positioned within the spleen to capture blood-borne Ag and immune complexes and deliver them to follicular dendritic cells in the B cell follicles. We show that within the spleens of aged mice antigen (Ag) capture by MZ B cells, and their ability to shuttle between the follicle and MZ were impaired. The ability of aged MZ B cells to migrate towards the MZ chemoattractant sphingosine 1-phosphate was increased, suggesting that aged MZ B cells had a greater propensity to be retained within the MZ. An extrinsic impairment in aged B cell migration towards the MZ was demonstrated using bone marrow chimeras. The follicular shuttling of MZ B cells derived from either young or aged bone marrow was similarly reduced in aged recipient spleens, showing that ageing effects on splenic stromal cells were responsible for the impaired follicular shuttling of MZ B cells. MZ B cells rapidly mount T cell-independent (TI) antibody-responses to microbial polysaccharide Ag. In aged mice the ability to produce immunoglobulins in response to the TI-type 1 Ag, TNP-LPS, was impaired. These ageing related changes to the MZ and MZ B cells have implications for the clearance of blood-borne pathogens. Indeed elderly people have increased susceptibility to Streptococcus pneumoniae, a TI Ag, and decreased responses to vaccination. A thorough analysis of the mechanisms that underpin the ageing-related decline in the status of the MZ and MZ B cells will help the design of novel treatments to improve immunity in the elderly. This article is protected by copyright. All rights reserved.

  10. Acute Hypoxic Stress Affects Migration Machinery of Tissue O2-Adapted Adipose Stromal Cells

    PubMed Central

    Lobanova, Margarita V.; Andreeva, Elena R.

    2016-01-01

    The ability of mesenchymal stromal (stem) cells (MSCs) to be mobilised from their local depot towards sites of injury and to participate in tissue repair makes these cells promising candidates for cell therapy. Physiological O2 tension in an MSC niche in vivo is about 4–7%. However, most in vitro studies of MSC functional activity are performed at 20% O2. Therefore, this study focused on the effects of short-term hypoxic stress (0.1% O2, 24 h) on adipose tissue-derived MSC motility at tissue-related O2 level. No significant changes in integrin expression were detected after short-term hypoxic stress. However, O2 deprivation provoked vimentin disassembly and actin polymerisation and increased cell stiffness. In addition, hypoxic stress induced the downregulation of ACTR3, DSTN, MACF1, MID1, MYPT1, NCK1, ROCK1, TIAM1, and WASF1 expression, the products of which are known to be involved in leading edge formation and cell translocation. These changes were accompanied by the attenuation of targeted and nontargeted migration of MSCs after short-term hypoxic exposure, as demonstrated in scratch and transwell migration assays. These results indicate that acute hypoxic stress can modulate MSC function in their native milieu, preventing their mobilisation from sites of injury. PMID:28115943

  11. Expression of CHODL in hepatocellular carcinoma affects invasion and migration of liver cancer cells

    PubMed Central

    Huang, Zejian; Zhang, Ning; Li, Wenda; Cao, Jun; Zhang, Lei; Chen, Yajin

    2017-01-01

    Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated death. Due to rapid progression and metastasis, the long-term survival remains poor for most patients. Thus, it is important to discover and develop novel preventive strategies and therapeutic approaches for HCC. Recent data show that chondrolectin (CHODL) is commonly overexpressed in the majority of lung cancers, indicating a possible correlation between CHODL and metastasis of lung cancer cells. Our investigation shows that the expression of CHODL is significantly decreased in HCC clinical samples and in HCC cell lines. Overexpression of CHODL in SMMC7721 cells with a lentiviral vector increased SMMC7721 cell migration and invasion. Our findings establish for the first time an association between human CHODL and HCC metastasis. PMID:28356950

  12. 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

  13. 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

  14. Tetraspanins in Cell Migration

    PubMed Central

    Jiang, Xupin; Zhang, Jiaping; Huang, Yuesheng

    2015-01-01

    Tetraspanins are a superfamily of small transmembrane proteins that are expressed in almost all eukaryotic cells. Through interacting with one another and with other membrane and intracellular proteins, tetraspanins regulate a wide range of proteins such as integrins, cell surface receptors, and signaling molecules, and thereby engage in diverse cellular processes ranging from cell adhesion and migration to proliferation and differentiation. In particular, tetraspanins modulate the function of proteins involved in all determining factors of cell migration including cell–cell adhesion, cell–ECM adhesion, cytoskeletal protrusion/contraction, and proteolytic ECM remodeling. We herein provide a brief overview of collective in vitro and in vivo studies of tetraspanins to illustrate their regulatory functions in the migration and trafficking of cancer cells, vascular endothelial cells, skin cells (keratinocytes and fibroblasts), and leukocytes. We also discuss the involvement of tetraspanins in various pathologic and remedial processes that rely on cell migration and their potential value as targets for therapeutic intervention. PMID:26091149

  15. Cell migration, freshly squeezed.

    PubMed

    Welch, Matthew D

    2015-02-12

    Migrating cells exhibit distinct motility modes and can switch between modes based on chemical or physical cues. Liu et al. and Ruprecht et al. now describe how confinement and contractility influence motility mode plasticity and instigate a mode termed stable bleb migration in embryonic and tumor cells.

  16. The overexpression of SOX2 affects the migration of human teratocarcinoma cell line NT2/D1.

    PubMed

    Drakulic, Danijela; Vicentic, Jelena Marjanovic; Schwirtlich, Marija; Tosic, Jelena; Krstic, Aleksandar; Klajn, Andrijana; Stevanovic, Milena

    2015-03-01

    The altered expression of the SOX2 transcription factor is associated with oncogenic or tumor suppressor functions in human cancers. This factor regulates the migration and invasion of different cancer cells. In this study we investigated the effect of constitutive SOX2 overexpression on the migration and adhesion capacity of embryonal teratocarcinoma NT2/D1 cells derived from a metastasis of a human testicular germ cell tumor. We detected that increased SOX2 expression changed the speed, mode and path of cell migration, but not the adhesion ability of NT2/D1 cells. Additionally, we demonstrated that SOX2 overexpression increased the expression of the tumor suppressor protein p53 and the HDM2 oncogene. Our results contribute to the better understanding of the effect of SOX2 on the behavior of tumor cells originating from a human testicular germ cell tumor. Considering that NT2/D1 cells resemble cancer stem cells in many features, our results could contribute to the elucidation of the role of SOX2 in cancer stem cells behavior and the process of metastasis.

  17. Accelerated Wound Closure - Differently Organized Nanofibers Affect Cell Migration and Hence the Closure of Artificial Wounds in a Cell Based In Vitro Model

    PubMed Central

    2017-01-01

    Nanofiber meshes holds great promise in wound healing applications by mimicking the topography of extracellular matrix, hence providing guidance for crucial cells involved in the regenerative processes. Here we explored the influence of nanofiber alignment on fibroblast behavior in a novel in vitro wound model. The model included electrospun poly-ε-caprolactone scaffolds with different nanofiber orientation. Fibroblasts were cultured to confluency for 24h before custom-made inserts were removed, creating cell-free zones serving as artificial wounds. Cell migration into these wounds was evaluated at 0-, 48- and 96h. Cell morphological analysis was performed using nuclei- and cytoskeleton stainings. Cell viability was assessed using a biochemical assay. This study demonstrates a novel in vitro wound assay, for exploring of the impact of nanofibers on wound healing. Additionally we show that it’s possible to affect the process of wound closure in a spatial manner using nanotopographies, resulting in faster closure on aligned fiber substrates. PMID:28060880

  18. 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

  19. The Lnc RNA SPRY4-IT1 Modulates Trophoblast Cell Invasion and Migration by Affecting the Epithelial-Mesenchymal Transition

    PubMed Central

    Zuo, Qing; Huang, Shiyun; Zou, Yanfen; Xu, Yetao; Jiang, Ziyan; Zou, Shan; Xu, Haoqing; Sun, Lizhou

    2016-01-01

    Preeclampsia is a common, pregnancy-specific disease and a major contributor to maternal and foetal morbidity and mortality. Some placental abnormalities, including deficient implantation, abnormal trophoblast cell function, and improper placental vascular development, are believed to lead to preeclampsia. The long noncoding RNA SPRY4-IT1 is more highly expressed in preeclamptic human placentas than in normal placentas. We assessed the role of epithelial-mesenchymal transition (EMT)-associated invasion and migration in HTR-8/SVneo trophoblast cells. Overexpression of SPRY4-IT1 suppressed trophoblast cell migration and invasion, whereas reduced expression of SPRY4-IT1 prevented the EMT process. Mechanistically, an RNA immunoprecipitation experiment showed that SPRY4-IT1 bound directly to HuR and mediated the β-catenin expression associated with EMT in HTR-8/SVneo cells. Moreover, the expression levels of genes in the WNT family, such as WNT3 and WNT5B, were changed after transfection of HTR-8/SVneo with SPRY4-IT1. Together, our results highlight the roles of SPRY4-IT1 in causing trophoblast cell dysfunction by acting through the Wnt/β-catenin pathway, and consequently in impairing spiral artery remodelling. These results suggest a new potential therapeutic target for intervention against preeclampsia. PMID:27853262

  20. JWA loss promotes cell migration and cytoskeletal rearrangement by affecting HER2 expression and identifies a high-risk subgroup of HER2-positive gastric carcinoma patients

    PubMed Central

    Qian, Jing; Zhu, Weiyou; Wang, Keming; Ma, Lin; Xu, Jin; Xu, Tongpeng; Røe, Oluf Dimitri; Li, Aiping; Zhou, Jianwei; Shu, Yongqian

    2016-01-01

    Background and Aims JWA, a microtubule-associated protein (MAP) involved in apoptosis, has been identified as a suppressor of metastasis, and it affects cell migration in melanoma and its downregulation in tumor is an idependent negative prognostic factor in resectable gastric cancer. HER2 overexpression has been observed in gastric cancer (GC) cells and implicated in the metastatic phenotype. However, the biological role of JWA in migration and its clinical value in HER2-positive GC remain elusive. Results JWA suppresses EGF-induced cell migration and actin cytoskeletal rearrangement by abrogating HER2 expression and downstream PI3K/AKT signaling in HER2-overexpressing GC cell lines. The modulation of HER2 by JWA is dependent on ERK activation and consequent PEA3 upregulation and activation. Reduced JWA expression is associated with high HER2 expression and with poor survival in patients with AGC, whereas HER2 expression alone is not associated with survival. However, concomitant low JWA and high HER2 expression is associated with unfavorable outcomes. Additionally, when patients were stratified by JWA expression, those with higher HER2 expression in the low JWA expression subgroup exhibited worse survival. Methods The impact of JWA on the EGF-induced migration of HER2-positive GC cells was studied using transwell assays and G-LISA assays. Western blotting, real-time PCR, electrophoretic mobility shift assays and luciferase assays were utilized to investigate the mechanisms by which JWA affects HER2. The association of JWA with HER2 and its clinical value were further analyzed by IHC in 128 pairs of advanced gastric cancer (AGC) and adjacent normal tissue samples. Conclusions This study characterizes a novel mechanism for regulating cell motility in HER2-overexpressing GC cells involving JWA-mediated MEK/ERK/PEA3 signaling activation and HER2 downregulation. Furthermore, JWA may be a useful prognostic indicator for advanced GC and may help stratify HER2-positive

  1. Rho GTPases and cancer cell transendothelial migration.

    PubMed

    Reymond, Nicolas; Riou, Philippe; Ridley, Anne J

    2012-01-01

    Small Rho GTPases are major regulators of actin cytoskeleton dynamics and influence cell shape and migration. The expression of several Rho GTPases is often up-regulated in tumors and this frequently correlates with a poor prognosis for patients. Migration of cancer cells through endothelial cells that line the blood vessels, called transendothelial migration or extravasation, is a critical step during the metastasis process. The use of siRNA technology to target specifically each Rho family member coupled with imaging techniques allows the roles of individual Rho GTPases to be investigated. In this chapter we describe methods to assess how Rho GTPases affect the different steps of cancer cell transendothelial cell migration in vitro.

  2. Draxin, an axon guidance protein, affects chick trunk neural crest migration.

    PubMed

    Su, Yuhong; Naser, Iftekhar B; Islam, Shahidul M; Zhang, Sanbing; Ahmed, Giasuddin; Chen, Sandy; Shinmyo, Yohei; Kawakami, Minoru; Yamamura, Ken-ichi; Tanaka, Hideaki

    2009-12-01

    The neural crest is a multipotent population of migratory cells that arises in the central nervous system and subsequently migrates along defined stereotypic pathways. In the present work, we analyzed the role of a repulsive axon guidance protein, draxin, in the migration of neural crest cells. Draxin is expressed in the roof plate of the chick trunk spinal cord and around the early migration pathway of neural crest cells. Draxin modulates chick neural crest cell migration in vitro by reducing the polarization of these cells. When exposed to draxin, the velocity of migrating neural crest cells was reduced, and the cells changed direction so frequently that the net migration distance was also reduced. Overexpression of draxin also caused some early migrating neural crest cells to change direction to the dorsolateral pathway in the chick trunk region, presumably due to draxin's inhibitory activity. These results demonstrate that draxin, an axon guidance protein, can also affect trunk neural crest migration in the chick embryo.

  3. Cell migration in the forebrain.

    PubMed

    Marín, Oscar; Rubenstein, John L R

    2003-01-01

    The forebrain comprises an intricate set of structures that are required for some of the most complex and evolved functions of the mammalian brain. As a reflection of its complexity, cell migration in the forebrain is extremely elaborated, with widespread dispersion of cells across multiple functionally distinct areas. Two general modes of migration are distinguished in the forebrain: radial migration, which establishes the general cytoarchitectonical framework of the different forebrain subdivisions; and tangential migration, which increases the cellular complexity of forebrain circuits by allowing the dispersion of multiple neuronal types. Here, we review the cellular and molecular mechanisms underlying each of these types of migrations and discuss how emerging concepts in neuronal migration are reshaping our understanding of forebrain development in normal and pathological situations.

  4. 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.

  5. The translational blocking of α5 and α6 integrin subunits affects migration and invasion, and increases sensitivity to carboplatin of SKOV-3 ovarian cancer cell line.

    PubMed

    Villegas-Pineda, Julio César; Toledo-Leyva, Alfredo; Osorio-Trujillo, Juan Carlos; Hernández-Ramírez, Verónica Ivonne; Talamás-Rohana, Patricia

    2017-02-15

    Epithelial ovarian cancer is the most lethal gynecologic malignancy. Integrins, overexpressed in cancer, are involved in various processes that favor the development of the disease. This study focused on determining the degree of involvement of α5, α6 and β3 integrin subunits in the establishment/development of epithelial ovarian cancer (EOC), such as proliferation, migration, invasion, and response to carboplatin. The translation of the α5, α6 and β3 integrins was blocked using morpholines, generating morphant cells for these proteins, which were corroborated by immunofluorescence assays. WST-1 proliferation assay showed that silencing of α5, α6, and β3 integrins does not affect the survival of morphants. Wound healing and transwell chamber assays showed that blocking α5 and α6 integrins decrease, in lesser and greater level respectively, the migratory and the invasive capacity of SKOV-3 cells. Finally, blocking α5 and α6 integrins partially sensitized the cells response to carboplatin, while blocking integrin β3 generated resistance to this drug. Statistical analyses were performed with the GraphPad Prism 5.0 software employing one way and two-way ANOVA tests; data are shown as average±SD. Results suggest that α5 and α6 integrins could become good candidates for chemotherapy targets in EOC.

  6. 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.

  7. Cell migration on ridges and cliffs

    NASA Astrophysics Data System (ADS)

    Driscoll, Meghan; McCann, Colin; Kopace, Rael; Watts, John; Homan, Tess; Losert, Wolfgang

    2009-03-01

    The amoeba Dictyostelium discoideum is a model system for the study of cellular migration, an important physiological process that occurs in embryonic development, wound healing, and cancer metastasis. We study the motion of D. discoideum on surfaces with various topographies, particularly those that affect the direction of cellular migration. Topographical features, such as ridges and cliffs, were fabricated using multiphoton absorption polymerization. As the cells encountered these topographical features, we tracked their overall motions and shapes, as well as the locations and intensities of certain intracellular signals. We found that when cells undergoing chemokinesis, random migration in response to a chemical signal, encounter a ridge, they tend to move along that ridge, even if the ridge is shorter than the cell. When cells undergoing chemotaxis, directed migration in response to a chemical signal, are directed off of a cliff, they do not fall off the cliff. Instead, they search for new attachment points, eventually change direction, and continue moving along the edge of the cliff. Both ridges and cliffs affect more than just the motion of a cell; they also affect its shape.

  8. Cell migration in confined environments.

    PubMed

    Irimia, Daniel

    2014-01-01

    We describe a protocol for measuring the speed of human neutrophils migrating through small channels, in conditions of mechanical confinement comparable to those experienced by neutrophils migrating through tissues. In such conditions, we find that neutrophils move persistently, at constant speed for tens of minutes, enabling precise measurements at single cells resolution, for large number of cells. The protocol relies on microfluidic devices with small channels in which a solution of chemoattractant and a suspension of isolated neutrophils are loaded in sequence. The migration of neutrophils can be observed for several hours, starting within minutes after loading the neutrophils in the devices. The protocol is divided into four main steps: the fabrication of the microfluidic devices, the separation of neutrophils from whole blood, the preparation of the assay and cell loading, and the analysis of data. We discuss the practical steps for the implementation of the migration assays in biology labs, the adaptation of the protocols to various cell types, including cancer cells, and the supplementary device features required for precise measurements of directionality and persistence during migration.

  9. sp(2) -Iminosugar α-Glucosidase Inhibitor 1-C-octyl-2-oxa-3-oxocastanospermine Specifically Affected Breast Cancer Cell Migration through Stim1, β1-Integrin, and FAK Signaling Pathways.

    PubMed

    Gueder, Nahla; Allan, Ghada; Telliez, Marie-Sophie; Hague, Frédéric; Garcia Fernandez, José M; Sanchez-Fernandez, Elena M; Ortiz-Mellet, Carmen; Ahidouch, Ahmed; Ouadid-Ahidouch, Halima

    2017-02-01

    Aberrant glycosylation changes on many glycoproteins are often related to cancer progression and metastasis. sp(2) -Iminosugar-type castanospermine analogues, inhibitors of α-glucosidases, have been reported to exhibit antitumor activity. However, their effects on cell migration and the underlying molecular mechanism are not fully understood. Here, we investigated the effect of the pseudo- C-octyl glycoside 2-oxa-3-oxocastanospermine derivatives (CO-OCS) on breast cancer cells (MCF-7 and MDA-MB-231 cells), and MCF-10A mammary normal cell lines. We showed that CO-OCS treatment results in the drastic decrease of breast cancer cell migration without affecting cell proliferation. Furthermore, CO-OCS significantly reduced both the expression of β1-integrin, which is a crucial interacting partner of Focal Adhesion Kinase (FAK), and the phosphorylation rates of FAK and ERK1/2. CO-OCS also drastically reduced Ca(2+) entry through Store Operated Channels (SOC). Orai1 and Stim1, two N-glycosylated proteins, are involved in Store-Operated Calcium Entry (SOCE), and are essential for breast tumor cell migration. Our results showed that CO-OCS decreased the expression, at the protein level, of Stim1 without affecting that of Orai1. Moreover, cell migration and SOCE were attenuated by CO-OCS as well as when Stim1 was silenced. In contrast, in MCF-10A cells, CO-OCS slightly reduced cell migration, but was without effect on gene expression of Stim1, Orai1, β1-integrin or FAK and ERK1/2 activation. Our results provide strong evidence for a significant effect of CO-OCS on breast cancer cell migration and support that this effect was associated with β1-integrin, Stim1 and FAK signaling pathways. This article is protected by copyright. All rights reserved.

  10. 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.

  11. Nanoparticles migration in fractured rocks and affects on contaminant migration

    NASA Astrophysics Data System (ADS)

    Missana, Tiziana; Garcia-Gutierrez, Miguel; Alonso, Ursula

    2014-05-01

    In previous studies, the transport behavior of artificial (gold and latex) and natural (smectite clay) colloids, within a planar fracture in crystalline rock, was analyzed. In order to better understand the effects of colloid size, shape and surface charge on nanoparticle migration and especially on filtration processes on natural rock surfaces, different clay colloids and oxide nanoparticles were selected and their transport studied as a function of the residence time. In all the cases, (a fraction of) the nanoparticles travelled in the fracture as fast as or faster than water (with a retardation factor, Rf ≤ 1) and the observed Rf, was related to the Taylor dispersion coefficient, accounting for colloid size, water velocity and fracture width. However, under most of the cases, in contrast to the behavior of a conservative tracer, colloids recovery was much lower than 100 %. Differences in recovery between different nanoparticles, under similar residence times, were analyzed. In order to evaluate the possible consequences, on contaminant migration, of the presence of nanoparticles in the system, transport tests were carried out with both colloids and sorbing radionuclides. The overall capacity for colloids of enhancing radionuclide migration in crystalline rock fractures is discussed. Acknowledgments: The research leading to these results received funding from EU FP7/2007-2011 grant agreement Nº 295487 (BELBAR, Bentonite Erosion: effects on the Long term performance of the engineered Barrier and Radionuclide Transport) and by the Spanish Government under the project NANOBAG (CTM2011-2797).

  12. H3K27 acetylation activated-long non-coding RNA CCAT1 affects cell proliferation and migration by regulating SPRY4 and HOXB13 expression in esophageal squamous cell carcinoma.

    PubMed

    Zhang, Erbao; Han, Liang; Yin, Dandan; He, Xuezhi; Hong, Linzhi; Si, Xinxin; Qiu, Mantang; Xu, Tongpeng; De, Wei; Xu, Lin; Shu, Yongqian; Chen, Jinfei

    2016-12-11

    Recently, long non-coding RNAs (lncRNAs) have been shown to have important regulatory roles in human cancer biology. In our study, we found that lncRNA CCAT1, whose expression is significantly increased and is correlated with outcomes in Esophageal Squamous Cell Carcinoma (ESCC). Consecutive experiments confirmed that H3K27-acetylation could activate expression of colon cancer associated transcript-1 (CCAT1). Further experiments revealed that CCAT1 knockdown significantly repressed the proliferation and migration both in vitro and in vivo RNA-seq analysis revealed that CCAT1 knockdown preferentially affected genes that are linked to cell proliferation, cell migration and cell adhesion. Mechanistic investigations found that CCAT1 could serve as a scaffold for two distinct epigenetic modification complexes (5' domain of CCAT1 binding Polycomb Repressive Complex 2 (PRC2) while 3' domain of CCAT1 binding SUV39H1) and modulate the histone methylation of promoter of SPRY4 (sprouty RTK signaling antagonist 4) in nucleus. In cytoplasm, CCAT1 regulates HOXB13 as a molecular decoy for miR-7, a microRNA that targets both CCAT1 and HOXB13, thus facilitating cell growth and migration. Together, our data demonstrated the important roles of CCAT1 in ESCC oncogenesis and might serve as targets for ESCC diagnosis and therapy.

  13. 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.

  14. Cell migration and invasion assays.

    PubMed

    Moutasim, Karwan A; Nystrom, Maria L; Thomas, Gareth J

    2011-01-01

    A number of in vitro assays have been developed to study tumor cell motility. Historically, assays have been mainly monocellular, where carcinoma cells are studied in isolation. Scratch assays can be used to study the collective and directional movement of populations of cells, whereas two chamber assays lend themselves to the analysis of chemotactic/haptotactic migration and cell invasion. However, an inherent disadvantage of these assays is that they grossly oversimplify the complex process of invasion, lacking the tumor structural architecture and stromal components. Organotypic assays, where tumor cells are grown at an air/liquid interface on gels populated with stromal cells, are a more physiologically relevant method for studying 3-dimensional tumor invasion.

  15. Force transmission in migrating cells

    PubMed Central

    Sauser, Roger; Ambrosi, Davide; Meister, Jean-Jacques; Verkhovsky, Alexander B.

    2010-01-01

    During cell migration, forces generated by the actin cytoskeleton are transmitted through adhesion complexes to the substrate. To investigate the mechanism of force generation and transmission, we analyzed the relationship between actin network velocity and traction forces at the substrate in a model system of persistently migrating fish epidermal keratocytes. Front and lateral sides of the cell exhibited much stronger coupling between actin motion and traction forces than the trailing cell body. Further analysis of the traction–velocity relationship suggested that the force transmission mechanisms were different in different cell regions: at the front, traction was generated by a gripping of the actin network to the substrate, whereas at the sides and back, it was produced by the network’s slipping over the substrate. Treatment with inhibitors of the actin–myosin system demonstrated that the cell body translocation could be powered by either of the two different processes, actomyosin contraction or actin assembly, with the former associated with significantly larger traction forces than the latter. PMID:20100912

  16. 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.

  17. 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.

  18. Migration in action: profiling border cells.

    PubMed

    Jasper, Heinrich

    2006-04-01

    Acquiring the ability to migrate is essential for cells taking part in many developmental and disease processes. Two studies in this issue of Developmental Cell use gene expression profiling of purified border cells from the Drosophila ovary to characterize the molecular changes required in cells to initiate migration in vivo. Their results offer interesting new insights into a moving cell's physiology.

  19. Focal Adhesion-Independent Cell Migration.

    PubMed

    Paluch, Ewa K; Aspalter, Irene M; Sixt, Michael

    2016-10-06

    Cell migration is central to a multitude of physiological processes, including embryonic development, immune surveillance, and wound healing, and deregulated migration is key to cancer dissemination. Decades of investigations have uncovered many of the molecular and physical mechanisms underlying cell migration. Together with protrusion extension and cell body retraction, adhesion to the substrate via specific focal adhesion points has long been considered an essential step in cell migration. Although this is true for cells moving on two-dimensional substrates, recent studies have demonstrated that focal adhesions are not required for cells moving in three dimensions, in which confinement is sufficient to maintain a cell in contact with its substrate. Here, we review the investigations that have led to challenging the requirement of specific adhesions for migration, discuss the physical mechanisms proposed for cell body translocation during focal adhesion-independent migration, and highlight the remaining open questions for the future.

  20. 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.

  1. Random versus directionally persistent cell migration

    PubMed Central

    Petrie, Ryan J.; Doyle, Andrew D.; Yamada, Kenneth M.

    2009-01-01

    Directional migration is an important component of cell motility. Although the basic mechanisms of random cell movement are well characterized, no single model explains the complex regulation of directional migration. Multiple factors operate at each step of cell migration to stabilize lamellipodia and maintain directional migration. Factors such as topography of the extracellular matrix, the cellular polarity machinery, receptor signalling, integrin trafficking and co-receptors, and actin–myosin contraction converge on regulation of the Rho family of GTPases and control of lamellipodial protrusions to promote directional migration. PMID:19603038

  2. 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.

  3. Microdroplet chain array for cell migration assays.

    PubMed

    Ma, Yan; Pan, Jian-Zhang; Zhao, Shi-Ping; Lou, Qi; Zhu, Ying; Fang, Qun

    2016-11-29

    Establishing cell migration assays in multiple different microenvironments is important in the study of tissue repair and regeneration, cancer progression, atherosclerosis, and arthritis. In this work, we developed a miniaturized and massive parallel microfluidic platform for multiple cell migration assays combining the traditional membrane-based cell migration technique and the droplet-based microfluidic technique. Nanoliter-scale droplets are flexibly assembled as building blocks based on a porous membrane to form microdroplet chains with diverse configurations for different assay modes. Multiple operations including in-droplet 2D/3D cell culture, cell co-culture and cell migration induced by a chemoattractant concentration gradient in droplet chains could be flexibly performed with reagent consumption in the nanoliter range for each assay and an assay scale-up to 81 assays in parallel in one microchip. We have applied the present platform to multiple modes of cell migration assays including the accurate cell migration assay, competitive cell migration assay, biomimetic chemotaxis assay, and multifactor cell migration assay based on the organ-on-a-chip concept, for demonstrating its versatility, applicability, and potential in cell migration-related research.

  4. Quantitative analysis of cell migration using optical flow.

    PubMed

    Boric, Katica; Orio, Patricio; Viéville, Thierry; Whitlock, Kathleen

    2013-01-01

    Neural crest cells exhibit dramatic migration behaviors as they populate their distant targets. Using a line of zebrafish expressing green fluorescent protein (sox10:EGFP) in neural crest cells we developed an assay to analyze and quantify cell migration as a population, and use it here to characterize in detail the subtle defects in cell migration caused by ethanol exposure during early development. The challenge was to quantify changes in the in vivo migration of all Sox10:EGFP expressing cells in the visual field of time-lapse movies. To perform this analysis we used an Optical Flow algorithm for motion detection and combined the analysis with a fit to an affine transformation. Through this analysis we detected and quantified significant differences in the cell migrations of Sox10:EGFP positive cranial neural crest populations in ethanol treated versus untreated embryos. Specifically, treatment affected migration by increasing the left-right asymmetry of the migrating cells and by altering the direction of cell movements. Thus, by applying this novel computational analysis, we were able to quantify the movements of populations of cells, allowing us to detect subtle changes in cell behaviors. Because cranial neural crest cells contribute to the formation of the frontal mass these subtle differences may underlie commonly observed facial asymmetries in normal human populations.

  5. Dictyostelium cells migrate similarly on surfaces of varying chemical composition.

    PubMed

    McCann, Colin P; Rericha, Erin C; Wang, Chenlu; Losert, Wolfgang; Parent, Carole A

    2014-01-01

    During cell migration, cell-substrate binding is required for pseudopod anchoring to move the cell forward, yet the interactions with the substrate must be sufficiently weak to allow parts of the cell to de-adhere in a controlled manner during typical protrusion/retraction cycles. Mammalian cells actively control cell-substrate binding and respond to extracellular conditions with localized integrin-containing focal adhesions mediating mechanotransduction. We asked whether mechanotransduction also occurs during non-integrin mediated migration by examining the motion of the social amoeba Dictyostelium discoideum, which is thought to bind non-specifically to surfaces. We discovered that Dictyostelium cells are able to regulate forces generated by the actomyosin cortex to maintain optimal cell-surface contact area and adhesion on surfaces of various chemical composition and that individual cells migrate with similar speed and contact area on the different surfaces. In contrast, during collective migration, as observed in wound healing and metastasis, the balance between surface forces and protrusive forces is altered. We found that Dictyostelium collective migration dynamics are strongly affected when cells are plated on different surfaces. These results suggest that the presence of cell-cell contacts, which appear as Dictyostelium cells enter development, alter the mechanism cells use to migrate on surfaces of varying composition.

  6. Collective cell migration during inflammatory response

    NASA Astrophysics Data System (ADS)

    Wu, Di; Stroka, Kimberly; Aranda-Espinoza, Helim

    2012-02-01

    Wound scratch healing assays of endothelial cell monolayers is a simple model to study collective cell migration as a function of biological signals. A signal of particular interest is the immune response, which after initial wounding in vivo causes the release of various inflammatory factors such as tumor necrosis alpha (TNF-α). TNF-α is an innate inflammatory cytokine that can induce cell growth, cell necrosis, and change cell morphology. We studied the effects of TNF-α on collective cell migration using the wound healing assays and measured several migration metrics, such as rate of scratch closure, velocities of leading edge and bulk cells, closure index, and velocity correlation functions between migrating cells. We observed that TNF-α alters all migratory metrics as a function of the size of the scratch and TNF-α content. The changes observed in migration correlate with actin reorganization upon TNF-α exposure.

  7. Effect of Static Magnetic Field on Cell Migration

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yuichiro; Kawasumi, Masashi; Saito, Masao

    The effect of magnetic field on cell has long been investigated, but there are few quantitative investigations of the migration of cells. Cell-migration is important as one of the fundamental activities of the cell. This study proposes a method to evaluate quantitatively the cell-diffusion constant and the effect of static magnetic field on cell migration. The cell-lines are neuroblastoma (NG108-15), fibroblastoma (NIH/3T3) and osteoblastoma (MC3T3-E1). The static magnetic field of 30 mT or 120 mT is impressed by a permanent magnet in vertical or horizontal direction to the dish. It is shown that the cell-diffusion constant can represent the cell migration as the cell activity. It is found that the cell migration is enhanced by exposure to the magnetic field, depending on the kind of cell. It is conjectured that the effect of static magnetic field affects the cell migration, which is at the downstream of the information transmission.

  8. Quantifying modes of 3D cell migration

    PubMed Central

    Driscoll, Meghan K.; Danuser, Gaudenz

    2015-01-01

    Although it is widely appreciated that cells migrate in a variety of diverse environments in vivo, we are only now beginning to use experimental workflows that yield images with sufficient spatiotemporal resolution to study the molecular processes governing cell migration in 3D environments. Since cell migration is a dynamic process, it is usually studied via microscopy, but 3D movies of 3D processes are difficult to interpret by visual inspection. In this review, we discuss the technologies required to study the diversity of 3D cell migration modes with a focus on the visualization and computational analysis tools needed to study cell migration quantitatively at a level comparable to the analyses performed today on cells crawling on flat substrates. PMID:26603943

  9. Quantifying Modes of 3D Cell Migration.

    PubMed

    Driscoll, Meghan K; Danuser, Gaudenz

    2015-12-01

    Although it is widely appreciated that cells migrate in a variety of diverse environments in vivo, we are only now beginning to use experimental workflows that yield images with sufficient spatiotemporal resolution to study the molecular processes governing cell migration in 3D environments. Since cell migration is a dynamic process, it is usually studied via microscopy, but 3D movies of 3D processes are difficult to interpret by visual inspection. In this review, we discuss the technologies required to study the diversity of 3D cell migration modes with a focus on the visualization and computational analysis tools needed to study cell migration quantitatively at a level comparable to the analyses performed today on cells crawling on flat substrates.

  10. Quantitative evaluation of the transplanted lin(-) hematopoietic cell migration kinetics.

    PubMed

    Kašėta, Vytautas; Vaitkuvienė, Aida; Liubavičiūtė, Aušra; Maciulevičienė, Rūta; Stirkė, Arūnas; Biziulevičienė, Genė

    2016-02-01

    Stem cells take part in organogenesis, cell maturation and injury repair. The migration is necessary for each of these functions to occur. The aim of this study was to investigate the kinetics of transplanted hematopoietic lin(-) cell population (which consists mainly of the stem and progenitor cells) in BALB/c mouse contact hypersensitivity model and quantify the migration to the site of inflammation in the affected foot and other healthy organs. Quantitative analysis was carried out with the real-time polymerase chain reaction method. Spleen, kidney, bone marrow, lung, liver, damaged and healthy foot tissue samples at different time points were collected for analysis. The quantitative data normalization was performed according to the comparative quantification method. The analysis of foot samples shows the significant migration of transplanted cells to the recipient mice affected foot. The quantity was more than 1000 times higher, as compared with that of the untreated foot. Due to the inflammation, the number of donor origin cells migrating to the lungs, liver, spleen and bone marrow was found to be decreased. Our data shows that transplanted cells selectively migrated into the inflammation areas of the foot edema. Also, the inflammation caused a secondary migration in ectopic spleen of hematopoietic stem cell niches and re-homing from the spleen to the bone marrow took place.

  11. 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

  12. 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.

  13. Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi.

    PubMed

    Parker, Aimee; Maclaren, Oliver J; Fletcher, Alexander G; Muraro, Daniele; Kreuzaler, Peter A; Byrne, Helen M; Maini, Philip K; Watson, Alastair J M; Pin, Carmen

    2017-02-01

    The functional integrity of the intestinal epithelial barrier relies on tight coordination of cell proliferation and migration, with failure to regulate these processes resulting in disease. It is not known whether cell proliferation is sufficient to drive epithelial cell migration during homoeostatic turnover of the epithelium. Nor is it known precisely how villus cell migration is affected when proliferation is perturbed. Some reports suggest that proliferation and migration may not be related while other studies support a direct relationship. We used established cell-tracking methods based on thymine analog cell labeling and developed tailored mathematical models to quantify cell proliferation and migration under normal conditions and when proliferation is reduced and when it is temporarily halted. We found that epithelial cell migration velocities along the villi are coupled to cell proliferation rates within the crypts in all conditions. Furthermore, halting and resuming proliferation results in the synchronized response of cell migration on the villi. We conclude that cell proliferation within the crypt is the primary force that drives cell migration along the villus. This methodology can be applied to interrogate intestinal epithelial dynamics and characterize situations in which processes involved in cell turnover become uncoupled, including pharmacological treatments and disease models.-Parker, A., Maclaren, O. J., Fletcher, A. G., Muraro, D., Kreuzaler, P. A., Byrne, H. M., Maini, P. K., Watson, A. J. M., Pin, C. Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi.

  14. Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi

    PubMed Central

    Parker, Aimee; Maclaren, Oliver J.; Fletcher, Alexander G.; Muraro, Daniele; Kreuzaler, Peter A.; Byrne, Helen M.; Maini, Philip K.; Watson, Alastair J. M.; Pin, Carmen

    2017-01-01

    The functional integrity of the intestinal epithelial barrier relies on tight coordination of cell proliferation and migration, with failure to regulate these processes resulting in disease. It is not known whether cell proliferation is sufficient to drive epithelial cell migration during homoeostatic turnover of the epithelium. Nor is it known precisely how villus cell migration is affected when proliferation is perturbed. Some reports suggest that proliferation and migration may not be related while other studies support a direct relationship. We used established cell-tracking methods based on thymine analog cell labeling and developed tailored mathematical models to quantify cell proliferation and migration under normal conditions and when proliferation is reduced and when it is temporarily halted. We found that epithelial cell migration velocities along the villi are coupled to cell proliferation rates within the crypts in all conditions. Furthermore, halting and resuming proliferation results in the synchronized response of cell migration on the villi. We conclude that cell proliferation within the crypt is the primary force that drives cell migration along the villus. This methodology can be applied to interrogate intestinal epithelial dynamics and characterize situations in which processes involved in cell turnover become uncoupled, including pharmacological treatments and disease models.—Parker, A., Maclaren, O. J., Fletcher, A. G., Muraro, D., Kreuzaler, P. A., Byrne, H. M., Maini, P. K., Watson, A. J. M., Pin, C. Cell proliferation within small intestinal crypts is the principal driving force for cell migration on villi. PMID:27811059

  15. 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.

  16. A Customizable Chamber for Measuring Cell Migration.

    PubMed

    Chowdhury, Aniqa N; Vo, Huu Tri; Olang, Sharon; Mappus, Elliott; Peterson, Brian; Hlavac, Nora; Harvey, Tyler; Dean, Delphine

    2017-03-12

    Cell migration is a vital part of immune responses, growth, and wound healing. Cell migration is a complex process that involves interactions between cells, the extracellular matrix, and soluble and non-soluble chemical factors (e.g., chemoattractants). Standard methods for measuring the migration of cells, such as the Boyden chamber assay, work by counting cells on either side of a divider. These techniques are easy to use; however, they offer little geometric modification for different applications. In contrast, microfluidic devices can be used to observe cell migration with customizable concentration gradients of soluble factors(1)(,)(2). However, methods for making microfluidics based assays can be difficult to learn. Here, we describe an easy method for creating cell culture chambers to measure cell migration in response to chemical concentration gradients. Our cell migration chamber method can create different linear concentration gradients in order to study cell migration for a variety of applications. This method is relatively easy to use and is typically performed by undergraduate students. The microchannel chamber was created by placing an acrylic insert in the shape of the final microchannel chamber well into a Petri dish. After this, poly(dimethylsiloxane) (PDMS) was poured on top of the insert. The PDMS was allowed to harden and then the insert was removed. This allowed for the creation of wells in any desired shape or size. Cells may be subsequently added to the microchannel chamber, and soluble agents can be added to one of the wells by soaking an agarose block in the desired agent. The agarose block is added to one of the wells, and time-lapse images can be taken of the microchannel chamber in order to quantify cell migration. Variations to this method can be made for a given application, making this method highly customizable.

  17. 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.

  18. Cell Shape Dynamics: From Waves to Migration

    NASA Astrophysics Data System (ADS)

    Driscoll, Meghan; McCann, Colin; Kopace, Rael; Homan, Tess; Fourkas, John; Parent, Carole; Losert, Wolfgang

    2011-03-01

    We analyzed the dynamic shape of migrating Dictyostelium discoideum cells. We found that regions of high boundary curvature propagate from the front to the back of cells in an organized fashion. These waves of high curvature are stabilized by surface contact, and so, at the sides of cells, are stationary relative to the surface. The initiation of curvature waves, though, which usually occurs at the front of cells, is associated with protrusive motion. The protrusion location shifts rapidly in a ballistic manner at speeds nearly double that of cellular migration. To examine curvature waves in the absence of surface contact, we guided cells to extend over the edge of micro-cliffs. The curvature wave speed of cells extended over a cliff was triple the wave speed of cells migrating on a surface, which is consistent with the higher wave speeds observed near the non-adherent leading edge of cells.

  19. 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.

  20. In vitro cell migration and invasion assays.

    PubMed

    Justus, Calvin R; Leffler, Nancy; Ruiz-Echevarria, Maria; Yang, Li V

    2014-06-01

    Migration is a key property of live cells and critical for normal development, immune response, and disease processes such as cancer metastasis and inflammation. Methods to examine cell migration are very useful and important for a wide range of biomedical research such as cancer biology, immunology, vascular biology, cell biology and developmental biology. Here we use tumor cell migration and invasion as an example and describe two related assays to illustrate the commonly used, easily accessible methods to measure these processes. The first method is the cell culture wound closure assay in which a scratch is generated on a confluent cell monolayer. The speed of wound closure and cell migration can be quantified by taking snapshot pictures with a regular inverted microscope at several time intervals. More detailed cell migratory behavior can be documented using the time-lapse microscopy system. The second method described in this paper is the transwell cell migration and invasion assay that measures the capacity of cell motility and invasiveness toward a chemo-attractant gradient. It is our goal to describe these methods in a highly accessible manner so that the procedures can be successfully performed in research laboratories even just with basic cell biology setup.

  1. 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

  2. Mesenchymal Stem Cells Induce Directional Migration of Invasive Breast Cancer Cells through TGF-β

    PubMed Central

    McAndrews, Kathleen M.; McGrail, Daniel J.; Ravikumar, Nithin; Dawson, Michelle R.

    2015-01-01

    Mesenchymal stem cells (MSCs) are recruited to the tumor microenvironment and influence tumor progression; however, how MSCs induce the invasion of cancer cells is not completely understood. Here, we used a 3D coculture model to determine how MSCs affect the migration of invasive breast cancer cells. Coculture with MSCs increases the elongation, directional migration, and traction generation of breast cancer cells. MSC-induced directional migration directly correlates with traction generation and is mediated by transforming growth factor β (TGF-β) and the migratory proteins rho-associated kinase, focal adhesion kinase, and matrix metalloproteinases. Treatment with MSC conditioned media or recombinant TGF-β1 elicits a similar migration response to coculture. Taken together, this work suggests TGF-β is secreted by MSCs, leading to force-dependent directional migration of invasive breast cancer cells. These pathways may be potential targets for blocking cancer cell invasion and subsequent metastasis. PMID:26585689

  3. Attraction rules: germ cell migration in zebrafish.

    PubMed

    Raz, Erez; Reichman-Fried, Michal

    2006-08-01

    The migration of zebrafish primordial germ cell towards the region where the gonad develops is guided by the chemokine SDF-1a. Recent studies show that soon after their specification, the cells undergo a series of morphological alterations before they become motile and are able to respond to attractive cues. As migratory cells, primordial germ cells move towards their target while correcting their path upon exiting a cyclic phase in which morphological cell polarity is lost. In the following stages, the cells gather at specific locations and move as cell clusters towards their final target. In all of these stages, zebrafish germ cells respond as individual cells to alterations in the shape of the sdf-1a expression domain, by directed migration towards their target - the position where the gonad develops.

  4. Building Responsive Health Systems to Help Communities Affected by Migration: An International Delphi Consensus.

    PubMed

    Pottie, Kevin; Hui, Charles; Rahman, Prinon; Ingleby, David; Akl, Elie A; Russell, Grant; Ling, Li; Wickramage, Kolitha; Mosca, Davide; Brindis, Claire D

    2017-02-03

    Persons affected by migration require health systems that are responsive and adaptable to the needs of both disadvantaged migrants and non-migrant populations. The objective of this study is to support health systems for populations affected by migration.

  5. Dissecting mesenchymal stem cell movement: migration assays for tracing and deducing cell migration.

    PubMed

    Spaeth, Erika L; Marini, Frank C

    2011-01-01

    Targeted migration is a necessary attribute for any gene delivery vehicle. Mesenchymal stem cells (MSC) have been used as effective delivery vehicles for treatments against cancer, graft versus host disease, -arthritis, multiple sclerosis, and many other diseases. MSC migrate toward sites of inflammation, however, the true migratory mechanism has yet to be elucidated. There are several receptors and respective chemokines known to be involved in the migration of the MSC. Further insight to MSC migration will be revealed both in vivo and in vitro through the application of migration assays from the most simple, to the more technologically demanding.

  6. A Novel Collagen Dot Assay for Monitoring Cancer Cell Migration.

    PubMed

    Alford, Vincent M; Roth, Eric; Zhang, Qian; Cao, Jian

    2016-01-01

    Cell migration is a critical determinant of cancer invasion and metastasis. Drugs targeting cancer cell migration have been hindered due to the lack of effective assays for monitoring cancer cell migration. Here we describe a novel method to microscopically monitor cell migration in a quantitative fashion. This assay can be used to study genes involved in cancer cell migration, as well as screening anticancer drugs that target this cellular process.

  7. Study of cell migration in microfabricated channels.

    PubMed

    Vargas, Pablo; Terriac, Emmanuel; Lennon-Duménil, Ana-Maria; Piel, Matthieu

    2014-02-21

    The method described here allows the study of cell migration under confinement in one dimension. It is based on the use of microfabricated channels, which impose a polarized phenotype to cells by physical constraints. Once inside channels, cells have only two possibilities: move forward or backward. This simplified migration in which directionality is restricted facilitates the automatic tracking of cells and the extraction of quantitative parameters to describe cell movement. These parameters include cell velocity, changes in direction, and pauses during motion. Microchannels are also compatible with the use of fluorescent markers and are therefore suitable to study localization of intracellular organelles and structures during cell migration at high resolution. Finally, the surface of the channels can be functionalized with different substrates, allowing the control of the adhesive properties of the channels or the study of haptotaxis. In summary, the system here described is intended to analyze the migration of large cell numbers in conditions in which both the geometry and the biochemical nature of the environment are controlled, facilitating the normalization and reproducibility of independent experiments.

  8. Collective cell migration: guidance principles and hierarchies.

    PubMed

    Haeger, Anna; Wolf, Katarina; Zegers, Mirjam M; Friedl, Peter

    2015-09-01

    Collective cell migration results from the establishment and maintenance of collective polarization, mechanocoupling, and cytoskeletal kinetics. The guidance of collective cell migration depends on a reciprocal process between cell-intrinsic multicellular organization with leader-follower cell behavior and results in mechanosensory integration of extracellular guidance cues. Important guidance mechanisms include chemotaxis, haptotaxis, durotaxis, and strain-induced mechanosensing to move cell groups along interfaces and paths of least resistance. Additional guidance mechanisms steering cell groups during specialized conditions comprise electrotaxis and passive drift. To form higher-order cell and tissue structures during morphogenesis and cancer invasion, these guidance principles act in parallel and are integrated for collective adaptation to and shaping of varying tissue environments. We review mechanochemical and electrical inputs and multiparameter signal integration underlying collective guidance, decision making, and outcome.

  9. In vitro cell migration and invasion assays.

    PubMed

    Kramer, Nina; Walzl, Angelika; Unger, Christine; Rosner, Margit; Krupitza, Georg; Hengstschläger, Markus; Dolznig, Helmut

    2013-01-01

    Determining the migratory and invasive capacity of tumor and stromal cells and clarifying the underlying mechanisms is most relevant for novel strategies in cancer diagnosis, prognosis, drug development and treatment. Here we shortly summarize the different modes of cell travelling and review in vitro methods, which can be used to evaluate migration and invasion. We provide a concise summary of established migration/invasion assays described in the literature, list advantages, limitations and drawbacks, give a tabular overview for convenience and depict the basic principles of the assays graphically. In many cases particular research problems and specific cell types do not leave a choice for a broad variety of usable assays. However, for most standard applications using adherent cells, based on our experience we suggest to use exclusion zone assays to evaluate migration/invasion. We substantiate our choice by demonstrating that the advantages outbalance the drawbacks e.g. the simple setup, the easy readout, the kinetic analysis, the evaluation of cell morphology and the feasibility to perform the assay with standard laboratory equipment. Finally, innovative 3D migration and invasion models including heterotypic cell interactions are discussed. These methods recapitulate the in vivo situation most closely. Results obtained with these assays have already shed new light on cancer cell spreading and potentially will uncover unknown mechanisms.

  10. Primary mesenchyme cell migration requires a chondroitin sulfate/dermatan sulfate proteoglycan.

    PubMed

    Lane, M C; Solursh, M

    1991-02-01

    Primary mesenchyme cell migration in the sea urchin embryo is inhibited by sulfate deprivation and exposure to exogenous beta-D-xylosides, two treatments known to disrupt proteoglycan synthesis. We show that in the developing sea urchin, exogenous xyloside affects the synthesis by the primary mesenchyme cells of a very large, cell surface chondroitin sulfate/dermatan sulfate proteoglycan. This proteoglycan is present in a partially purified fraction that restores migratory ability to defective cells in vitro. The integrity of this chondroitin sulfate/dermatan sulfate proteoglycan appears essential for primary mesenchyme cell migration since treatment of actively migrating cells with chondroitinase ABC reversibly inhibited their migration in vitro.

  11. Engineered Models of Confined Cell Migration

    PubMed Central

    Paul, Colin D.; Hung, Wei-Chien; Wirtz, Denis; Konstantopoulos, Konstantinos

    2017-01-01

    Cells in the body are physically confined by neighboring cells, tissues, and the extracellular matrix. Although physical confinement modulates intracellular signaling and the underlying mechanisms of cell migration, it is difficult to study in vivo. Furthermore, traditional two-dimensional cell migration assays do not recapitulate the complex topographies found in the body. Therefore, a number of experimental in vitro models that confine and impose forces on cells in well-defined microenvironments have been engineered. We describe the design and use of microfluidic microchannel devices, grooved substrates, micropatterned lines, vertical confinement devices, patterned hydrogels, and micropipette aspiration assays for studying cell responses to confinement. Use of these devices has enabled the delineation of changes in cytoskeletal reorganization, cell–substrate adhesions, intracellular signaling, nuclear shape, and gene expression that result from physical confinement. These assays and the physiologically relevant signaling pathways that have been elucidated are beginning to have a translational and clinical impact. PMID:27420571

  12. Glial chain migration requires pioneer cells.

    PubMed

    Aigouy, Benoît; Lepelletier, Léa; Giangrande, Angela

    2008-11-05

    The migration of glial chains along the nerve entails directional and coordinated movement. Despite its importance in the formation of the nervous system, this process remains poorly understood, because of the difficulty of manipulating identified cells. Using confocal time-lapse and cell ablation in the whole animal, we provide direct evidence for a discrete number of Drosophila peripheral glial cells acting as pioneers and guiding the rest of the migratory chain. These cells are in direct contact with several follower cells through a very long and stable cytoplasmic extension. The presence of pioneer cells and homotypic interactions at the tip of the chain allows coordinated movement and the formation of a continuous sheath around the nerve. These in vivo data open novel perspectives for understanding the cellular bases of vertebrate glial migration in physiological and pathological conditions.

  13. Chemokine Oligomerization in Cell Signaling and Migration

    PubMed Central

    Wang, Xu; Sharp, Joshua S.; Handel, Tracy M.; Prestegard, James H.

    2014-01-01

    Chemokines are small proteins best known for their role in controlling the migration of diverse cells, particularly leukocytes. Upon binding to their G-protein-coupled receptors on the leukocytes, chemokines stimulate the signaling events that cause cytoskeletal rearrangements involved in cell movement, and migration of the cells along chemokine gradients. Depending on the cell type, chemokines also induce many other types of cellular responses including those related to defense mechanisms, cell proliferation, survival, and development. Historically, most research efforts have focused on the interaction of chemokines with their receptors, where monomeric forms of the ligands are the functionally relevant state. More recently, however, the importance of chemokine interactions with cell surface glycosaminoglycans has come to light, and in most cases appears to involve oligomeric chemokine structures. This review summarizes existing knowledge relating to the structure and function of chemokine oligomers, and emerging methodology for determining structures of complex chemokine assemblies in the future. PMID:23663982

  14. Tumor cell migration is a superstatistical process

    NASA Astrophysics Data System (ADS)

    Fabry, Ben

    2014-03-01

    Over short time scales, cell migration can be well described as a homogeneous correlated random walk with a fixed average step length and a certain degree of directional persistence. On time scales of up to 24 h, however, the migration process is highly inhomogeneous. Superstatistical fluctuations of step length and directional persistence lead to ``anomalous'' features, such as an exponential step width distribution (SWD) and a superdiffusive mean squared displacement (MSD). These features are quantitatively reproduced by a correlated random walk with temporally varying persistence. By comparing cell migration on planar substrates and in a 3D collagen matrix, we demonstrate that the globally averaged MSD and SWD are not sensitive to the microscopic migration mechanism of the cells and can therefore yield identical results in these different environments. By contrast, the temporal fluctuations of step length and directional persistence, and their mutual correlations, provide a characteristic fingerprint of the migration process in different environments. In collaboration with Julian Steinwachs and Claus Metzner, Department of Physics, University of Erlangen-Nuremberg.

  15. Sphingolipids inhibit vimentin-dependent cell migration.

    PubMed

    Hyder, Claire L; Kemppainen, Kati; Isoniemi, Kimmo O; Imanishi, Susumu Y; Goto, Hidemasa; Inagaki, Masaki; Fazeli, Elnaz; Eriksson, John E; Törnquist, Kid

    2015-06-01

    The sphingolipids, sphingosine 1-phosphate (S1P) and sphingosylphosphorylcholine (SPC), can induce or inhibit cellular migration. The intermediate filament protein vimentin is an inducer of migration and a marker for epithelial-mesenchymal transition. Given that keratin intermediate filaments are regulated by SPC, with consequences for cell motility, we wanted to determine whether vimentin is also regulated by sphingolipid signalling and whether it is a determinant for sphingolipid-mediated functions. In cancer cells where S1P and SPC inhibited migration, we observed that S1P and SPC induced phosphorylation of vimentin on S71, leading to a corresponding reorganization of vimentin filaments. These effects were sphingolipid-signalling-dependent, because inhibition of either the S1P2 receptor (also known as S1PR2) or its downstream effector Rho-associated kinase (ROCK, for which there are two isoforms ROCK1 and ROCK2) nullified the sphingolipid-induced effects on vimentin organization and S71 phosphorylation. Furthermore, the anti-migratory effect of S1P and SPC could be prevented by expressing S71-phosphorylation-deficient vimentin. In addition, we demonstrated, by using wild-type and vimentin-knockout mouse embryonic fibroblasts, that the sphingolipid-mediated inhibition of migration is dependent on vimentin. These results imply that this newly discovered sphingolipid-vimentin signalling axis exerts brake-and-throttle functions in the regulation of cell migration.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. Signal Relay During Cell Migration

    NASA Astrophysics Data System (ADS)

    Guven, Can; Rericha, Erin; Ott, Edward; Losert, Wolfgang

    2012-02-01

    We developed a signal relay model to quantify the effect of intercellular communication in presence of an external signal, during the motion of groups of Dictyostelium discoideum cells. A key parameter is the ratio of amplitude of the cAMP (cyclic adenosine monophosphate) a signaling chemical secreted from individual cells versus the external cAMP field, which defines a time scale. Another time scale is set by the degradation rate of the cAMP. In our simulations, the competition between these two time scales results rich dynamics including uniform motion, as well as streaming and clustering instabilities. The simulations are compared to experiments for a wide range of different external signal strengths for both cells that secrete cAMP and a mutant which cannot relay cAMP. Under different strength of external linear cAMP gradient, the wild type cells form streams and exhibit clustering due to the intercellular signaling through individual cAMP secretion. In contrast, cells lacking signal relay move relatively straight. We find that the model captures both independent motion and the formation of aggregates when cells relay the signal.

  1. Myosin IIA dependent retrograde flow drives 3D cell migration.

    PubMed

    Shih, Wenting; Yamada, Soichiro

    2010-04-21

    Epithelial cell migration is an essential part of embryogenesis and tissue regeneration, yet their migration is least understood. Using our three-dimensional (3D) motility analysis, migrating epithelial cells formed an atypical polarized cell shape with the nucleus leading the cell front and a contractile cell rear. Migrating epithelial cells exerted traction forces to deform both the anterior and posterior extracellular matrix toward the cell body. The cell leading edge exhibited a myosin II-dependent retrograde flow with the magnitude and direction consistent with surrounding network deformation. Interestingly, on a two-dimensional substrate, myosin IIA-deficient cells migrated faster than wild-type cells, but in a 3D gel, these myosin IIA-deficient cells were unpolarized and immobile. In contrast, the migration rates of myosin IIB-deficient cells were similar to wild-type cells. Therefore, myosin IIA, not myosin IIB, is required for 3D epithelial cell migration.

  2. 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.

  3. 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

  4. The core planar cell polarity gene, Vangl2, directs adult corneal epithelial cell alignment and migration

    PubMed Central

    Findlay, Amy S.; Panzica, D. Alessio; Walczysko, Petr; Holt, Amy B.; Henderson, Deborah J.; West, John D.; Rajnicek, Ann M.

    2016-01-01

    This study shows that the core planar cell polarity (PCP) genes direct the aligned cell migration in the adult corneal epithelium, a stratified squamous epithelium on the outer surface of the vertebrate eye. Expression of multiple core PCP genes was demonstrated in the adult corneal epithelium. PCP components were manipulated genetically and pharmacologically in human and mouse corneal epithelial cells in vivo and in vitro. Knockdown of VANGL2 reduced the directional component of migration of human corneal epithelial (HCE) cells without affecting speed. It was shown that signalling through PCP mediators, dishevelled, dishevelled-associated activator of morphogenesis and Rho-associated protein kinase directs the alignment of HCE cells by affecting cytoskeletal reorganization. Cells in which VANGL2 was disrupted tended to misalign on grooved surfaces and migrate across, rather than parallel to the grooves. Adult corneal epithelial cells in which Vangl2 had been conditionally deleted showed a reduced rate of wound-healing migration. Conditional deletion of Vangl2 in the mouse corneal epithelium ablated the normal highly stereotyped patterns of centripetal cell migration in vivo from the periphery (limbus) to the centre of the cornea. Corneal opacity owing to chronic wounding is a major cause of degenerative blindness across the world, and this study shows that Vangl2 activity is required for directional corneal epithelial migration. PMID:27853583

  5. ERK-dependent and -independent pathways trigger human neural progenitor cell migration

    SciTech Connect

    Moors, Michaela . E-mail: moors@uni-duesseldorf.de; Cline, Jason E. . E-mail: jason.cline@uni-duesseldorf.de; Abel, Josef . E-mail: josef.abel@uni-duesseldorf.de; Fritsche, Ellen . E-mail: ellen.fritsche@uni-duesseldorf.de

    2007-05-15

    Besides differentiation and apoptosis, cell migration is a basic process in brain development in which neural cells migrate several centimeters within the developing brain before reaching their proper positions and forming the right connections. For identifying signaling events that control neural migration and are therefore potential targets of chemicals to disturb normal brain development, we developed a human neurosphere-based migration assay based on normal human neural progenitor (NHNP) cells, in which the distance is measured that cells wander over time. Applying this assay, we investigated the role of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) in the regulation of NHNP cell migration. Exposure to model substances like ethanol or phorbol 12-myristate 13-acetate (PMA) revealed a correlation between ERK1/2 activation and cell migration. The participation of phospho-(P-) ERK1/2 was confirmed by exposure of the cells to the MEK inhibitor PD98059, which directly prohibits ERK1/2 phosphorylation and inhibited cell migration. We identified protein kinase C (PKC) and epidermal growth factor receptor (EGFR) as upstream signaling kinases governing ERK1/2 activation, thereby controlling NHNP cell migration. Additionally, treatments with src kinase inhibitors led to a diminished cell migration without affecting ERK1/2 phosphorylation. Based on these results, we postulate that migration of NHNP cells is controlled via ERK1/2-dependent and -independent pathways.

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

    PubMed Central

    Bainton, Roland J; Heberlein, Ulrike

    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

  7. Cell Chirality Induces Collective Cell Migration in Epithelial Sheets

    NASA Astrophysics Data System (ADS)

    Sato, Katsuhiko; Hiraiwa, Tetsuya; Shibata, Tatsuo

    2015-10-01

    During early development, epithelial cells form a monolayer sheet and migrate in a uniform direction. Here, we address how this collective migration can occur without breaking the cell-to-cell attachments. Repeated contraction and expansion of the cell-to-cell interfaces enables the cells to rearrange their positions autonomously within the sheet. We show that when the interface tension is strengthened in a direction that is tilted from the body axis, cell rearrangements occur in such a way that unidirectional movement is induced. We use a vertex model to demonstrate that such anisotropic tension can generate the unidirectional motion of cell sheets. Our results suggest that cell chirality facilitates collective cell migration during tissue morphogenesis.

  8. Uveal melanoma cells utilize a novel route for transendothelial migration.

    PubMed

    Onken, Michael D; Li, Jinmei; Cooper, John A

    2014-01-01

    Uveal melanoma arises in the eye, and it spreads to distant organs in almost half of patients, leading to a fatal outcome. To metastasize, uveal melanoma cells must transmigrate into and out of the microvasculature, crossing the monolayer of endothelial cells that separates the vessel lumen from surrounding tissues. We investigated how human uveal melanoma cells cross the endothelial cell monolayer, using a cultured cell system with primary human endothelial cell monolayers on hydrogel substrates. We found that uveal melanoma cells transmigrate by a novel and unexpected mechanism. Uveal melanoma cells intercalate into the endothelial cell monolayer and flatten out, assuming a shape and geometry similar to those of endothelial cells in the monolayer. After an extended period of time in the intercalated state, the uveal melanoma cells round up and migrate underneath the monolayer. VCAM is present on endothelial cells, and anti-VCAM antibodies slowed the process of intercalation. Depletion of BAP1, a known suppressor of metastasis in patients, increased the amount of transmigration of uveal melanoma cells in transwell assays; but BAP1 depletion did not affect the rate of intercalation, based on movies of living cells. Our results reveal a novel route of transendothelial migration for uveal melanoma cells, and they provide insight into the mechanism by which loss of BAP1 promotes metastasis.

  9. 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.

  10. 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

    2016-09-02

    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.

  11. Migration dynamics of breast cancer cells in a tunable 3D interstitial flow chamber.

    PubMed

    Haessler, Ulrike; Teo, Jeremy C M; Foretay, Didier; Renaud, Philippe; Swartz, Melody A

    2012-04-01

    The migration of cells such as leukocytes, tumor cells, and fibroblasts through 3D matrices is critical for regulating homeostasis and immunity and for driving pathogenesis. Interstitial flow through the extracellular matrix, which can substantially increase during inflammation and in the tumor microenvironment, can influence cell migration in multiple ways. Leukocytes and tumor cells are heterogeneous in their migration responses to flow, yet most 3D migration studies use endpoint measurements representing average characteristics. Here we present a robust new microfluidic device for 3D culture with live imaging under well-controlled flow conditions, along with a comparison of analytical methods for describing the migration behavior of heterogeneous cell populations. We then use the model to provide new insight on how interstitial flow affects MDA-MB-231 breast cancer cell invasion, phenomena that are not seen from averaged or endpoint measurements. Specifically, we find that interstitial flow increases the percentage of cells that become migratory, and increases migrational speed in about 20% of the cells. It also increases the migrational persistence of a subpopulation (5-10% of cells) in the positive or negative flow direction. Cells that migrated upstream moved faster but with less directedness, whereas cells that migrated in the direction of flow moved at slower speeds but with higher directedness. These findings demonstrate how fluid flow in the tumor microenvironment can enhance tumor cell invasion by directing a subpopulation of tumor cells in the flow direction; i.e., towards the draining lymphatic vessels, a major route of metastasis.

  12. Collective cell migration: leadership, invasion and segregation.

    PubMed

    Kabla, Alexandre J

    2012-12-07

    A number of biological processes, such as embryo development, cancer metastasis or wound healing, rely on cells moving in concert. The mechanisms leading to the emergence of coordinated motion remain however largely unexplored. Although biomolecular signalling is known to be involved in most occurrences of collective migration, the role of physical and mechanical interactions has only been recently investigated. In this study, a versatile framework for cell motility is implemented in silico in order to study the minimal requirements for the coordination of a group of epithelial cells. We find that cell motility and cell-cell mechanical interactions are sufficient to generate a broad array of behaviours commonly observed in vitro and in vivo. Cell streaming, sheet migration and susceptibility to leader cells are examples of behaviours spontaneously emerging from these simple assumptions, which might explain why collective effects are so ubiquitous in nature. The size of the population and its confinement appear, in particular, to play an important role in the coordination process. In all cases, the complex response of the population can be predicted from the knowledge of the correlation length of the velocity field measured in the bulk of the epithelial layer. This analysis provides also new insights into cancer metastasis and cell sorting, suggesting, in particular, that collective invasion might result from an emerging coordination in a system where single cells are mechanically unable to invade.

  13. Paxillin: a crossroad in pathological cell migration.

    PubMed

    López-Colomé, Ana María; Lee-Rivera, Irene; Benavides-Hidalgo, Regina; López, Edith

    2017-02-18

    Paxilllin is a multifunctional and multidomain focal adhesion adapter protein which serves an important scaffolding role at focal adhesions by recruiting structural and signaling molecules involved in cell movement and migration, when phosphorylated on specific Tyr and Ser residues. Upon integrin engagement with extracellular matrix, paxillin is phosphorylated at Tyr31, Tyr118, Ser188, and Ser190, activating numerous signaling cascades which promote cell migration, indicating that the regulation of adhesion dynamics is under the control of a complex display of signaling mechanisms. Among them, paxillin disassembly from focal adhesions induced by extracellular regulated kinase (ERK)-mediated phosphorylation of serines 106, 231, and 290 as well as the binding of the phosphatase PEST to paxillin have been shown to play a key role in cell migration. Paxillin also coordinates the spatiotemporal activation of signaling molecules, including Cdc42, Rac1, and RhoA GTPases, by recruiting GEFs, GAPs, and GITs to focal adhesions. As a major participant in the regulation of cell movement, paxillin plays distinct roles in specific tissues and developmental stages and is involved in immune response, epithelial morphogenesis, and embryonic development. Importantly, paxillin is also an essential player in pathological conditions including oxidative stress, inflammation, endothelial cell barrier dysfunction, and cancer development and metastasis.

  14. 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

  15. Relative rigidity of cell-substrate effects on hepatic and hepatocellular carcinoma cell migration.

    PubMed

    Yangben, Yanzi; Wang, Hongbing; Zhong, Li; Chiang, Martin Y M; Tan, Qiaoyan; Singh, Gurinder K; Li, Song; Yang, Li

    2013-01-01

    Polyacrylamide gels with different stiffness and glass were employed as substrates to investigate how substrate stiffness affects the cellular stiffness of adherent hepatocellular carcinoma (HCCLM3) and hepatic (L02) cells. The interaction of how cell-substrate stiffness influences cell migration was also explored. An atom force microscope measured the stiffness of HCCLM3 and L02 cells on different substrates. Further, F-actin assembly was analyzed using immunofluorescence and Western blot. Finally, cell-surface expression of integrin β1 was quantified by flow cytometry. The results show that, while both HCCLM3 and L02 cells adjusted their cell stiffness to comply with the stiffness of the substrate they were adhered to, their tuning capabilities were different. HCCLM3 cell stiffness complied when substrate stiffness was between 1.1 and 33.7 kPa, whereas the analogous stiffness for L02 cells occurred at a higher substrate stiffness, 3.6 kPa up to glass. These ranges correlated with F-actin filament assembly and integrin β1 expression. In a migration assay, HCCLM3 cells migrated faster on a relatively soft substrate, while L02 cells migrated faster on substrates that were relatively rigid. These findings indicate that different tuning capabilities of HCCLM3 and L02 cells may influence cell migration velocity on substrates with different stiffness by regulating cy- toskeleton remodeling and integrin β1 expression.

  16. 25-Hydroxycholesterol promotes migration and invasion of lung adenocarcinoma cells.

    PubMed

    Chen, Li; Zhang, Lishan; Xian, Guozhe; Lv, Yinping; Lin, Yanliang; Wang, Yibing

    2017-03-18

    25-hydroxycholesterol (25-HC) is enzymatically produced by cholesterol 25-hydorxylase in various organs and is involved in many processes, including lipid metabolism, inflammation and the immune response. However, the role of 25-HC in the migration and invasion of lung adenocarcinoma (ADC) cells remains largely unknown. In this study, we demonstrated that 0.1 μM 25-HC promoted ADC cell migration and invasion without affecting cell proliferation, especially after coculture with THP1-derived macrophages. Further investigation showed that 0.1 μM 25-HC significantly stimulated interleukin-1β (IL-1β) secretion in a coculture system and increased the expression of LXR and Snail. IL-1β also mimicked the effect of 25-HC. LXR knockdown notably blocked the 25-HC-induced Snail expression, migration and invasion in both the monoculture system and the coculture system, but it did not impact the effect of IL-1β, which suggested that IL-1β functioned in an LXR-independent manner. These results suggested that 25-HC promoted ADC cell migration and invasion in an LXR-dependent manner in the monoculture system but that in the coculture system, the 25-HC-induced IL-1β secretion enhanced the effect of 25-HC in an LXR-independent manner.

  17. BMP2 rescues deficient cell migration in Tgfbr3(-/-) epicardial cells and requires Src kinase.

    PubMed

    Allison, Patrick; Espiritu, Daniella; Camenisch, Todd D

    2016-05-03

    During embryogenesis, the epicardium undergoes proliferation, migration, and differentiation into several cardiac cell types which contribute to the coronary vessels. The type III transforming growth factor-β receptor (TGFβR3) is required for epicardial cell invasion and development of coronary vasculature in vivo. Bone Morphogenic Protein-2 (BMP2) is a driver of epicardial cell migration. Utilizing a primary epicardial cell line derived from Tgfbr3(+/+) and Tgfbr3(-/-) mouse embryos, we show that Tgfbr3(-/-) epicardial cells are deficient in BMP2 mRNA expression. Tgfbr3(-/-) epicardial cells are deficient in 2-dimensional migration relative to Tgfbr3(+/+) cells; BMP2 induces cellular migration to Tgfbr3(+/+) levels without affecting proliferation. We further demonstrate that Src kinase activity is required for BMP2 driven Tgfbr3(-/-) migration. BMP2 also requires Src for filamentous actin polymerization in Tgfbr3(-/-) epicardial cells. Taken together, our data identifies a novel pathway in epicardial cell migration required for development of the coronary vessels.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. 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.

  20. 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.

  1. Arf proteins in cancer cell migration

    PubMed Central

    Casalou, Cristina; Faustino, Alexandra; Barral, Duarte C.

    2016-01-01

    ABSTRACT Members of the ADP-ribosylation factor (Arf) family of small GTP-binding (G) proteins regulate several aspects of membrane trafficking, such as vesicle budding, tethering and cytoskeleton organization. Arf family members, including Arf-like (Arl) proteins have been implicated in several essential cellular functions, like cell spreading and migration. These functions are used by cancer cells to disseminate and invade the tissues surrounding the primary tumor, leading to the formation of metastases. Indeed, Arf and Arl proteins, as well as their guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) have been found to be abnormally expressed in different cancer cell types and human cancers. Here, we review the current evidence supporting the involvement of Arf family proteins and their GEFs and GAPs in cancer progression, focusing on 3 different mechanisms: cell-cell adhesion, integrin internalization and recycling, and actin cytoskeleton remodeling. PMID:27589148

  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. Cell proliferation and migration in silk fibroin 3D scaffolds.

    PubMed

    Mandal, Biman B; Kundu, Subhas C

    2009-05-01

    Pore architecture in 3D polymeric scaffolds is known to play a critical role in tissue engineering as it provides the vital framework for the seeded cells to organize into a functioning tissue. In this report, we investigated the effects of different freezing temperature regimes on silk fibroin protein 3D scaffold pore microstructure. The fabricated scaffolds using freeze-dry technique were used as a 3D model to monitor cell proliferation and migration. Pores of 200-250microm diameter were formed by slow cooling at temperatures of -20 and -80 degrees C but were found to be limited in porosity and pore interconnectivity as observed through scanning electron microscopic images. In contrast, highly interconnected pores with 96% porosity were observed when silk solutions were rapidly frozen at -196 degrees C. A detailed study was conducted to assess the affect of pore size, porosity and interconnectivity on human dermal fibroblast cell proliferation and migration on these 3D scaffolds using confocal microscopy. The cells were observed to migrate within the scaffold interconnectivities and were found to reach scaffold periphery within 28 days of culture. Confocal images further confirmed normal cell attachment and alignment of actin filaments within the porous scaffold matrix with well-developed nuclei. This study indicates rapid freeze-drying technique as an alternative method to fabricate highly interconnected porous scaffolds for developing functional 3D silk fibroin matrices for potential tissue engineering, biomedical and biotechnological applications.

  4. 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.

  5. 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

  6. Cell Shape Dynamics: From Waves to Migration

    NASA Astrophysics Data System (ADS)

    Driscoll, Meghan; McCann, Colin; Sun, Xiaoyu; Fourkas, John; Parent, Carole; Losert, Wolfgang

    2012-02-01

    We observe and quantify wave-like characteristics of amoeboid migration. Using the amoeba Dictyostelium discoideum, a model system for the study of chemotaxis, we demonstrate that cell shape changes in a wave-like manner. Cells have regions of high boundary curvature that propagate from the leading edge toward the back, usually along alternating sides of the cell. Curvature waves are easily seen in cells that do not adhere to a surface, such as cells that are electrostatically repelled from surfaces or cells that extend over the edge of micro-fabricated cliffs. Without surface contact, curvature waves travel from the leading edge to the back of a cell at ˜35 μm/min. Non-adherent myosin II null cells do not exhibit these curvature waves. At the leading edge of adherent cells, curvature waves are associated with protrusive activity. Like regions of high curvature, protrusive activity travels along the boundary in a wave-like manner. Upon contact with a surface, the waves stop moving relative to the surface, and the boundary shape thus reflects the history of protrusive motion. The wave-like character of protrusions provides a plausible mechanism for the ability of cells to both swim in viscous fluids and to navigate complex 3-D topography.

  7. Cell Shape Dynamics: From Waves to Migration

    PubMed Central

    Driscoll, Meghan K.; McCann, Colin; Kopace, Rael; Homan, Tess; Fourkas, John T.; Parent, Carole; Losert, Wolfgang

    2012-01-01

    We observe and quantify wave-like characteristics of amoeboid migration. Using the amoeba Dictyostelium discoideum, a model system for the study of chemotaxis, we demonstrate that cell shape changes in a wave-like manner. Cells have regions of high boundary curvature that propagate from the leading edge toward the back, usually along alternating sides of the cell. Curvature waves are easily seen in cells that do not adhere to a surface, such as cells that are electrostatically repelled from surfaces or cells that extend over the edge of micro-fabricated cliffs. Without surface contact, curvature waves travel from the leading edge to the back of a cell at ∼35 µm/min. Non-adherent myosin II null cells do not exhibit these curvature waves. At the leading edge of adherent cells, curvature waves are associated with protrusive activity. Like regions of high curvature, protrusive activity travels along the boundary in a wave-like manner. Upon contact with a surface, the protrusions stop moving relative to the surface, and the boundary shape thus reflects the history of protrusive motion. The wave-like character of protrusions provides a plausible mechanism for the zig-zagging of pseudopods and for the ability of cells both to swim in viscous fluids and to navigate complex three dimensional topography. PMID:22438794

  8. Force mapping in epithelial cell migration

    PubMed Central

    du Roure, Olivia; Saez, Alexandre; Buguin, Axel; Austin, Robert H.; Chavrier, Philippe; Siberzan, Pascal; Ladoux, Benoit

    2005-01-01

    We measure dynamic traction forces exerted by epithelial cells on a substrate. The force sensor is a high-density array of elastomeric microfabricated pillars that support the cells. Traction forces induced by cell migration are deduced from the measurement of the bending of these pillars and are correlated with actin localization by fluorescence microscopy. We use a multiple-particle tracking method to estimate the mechanical activity of cells in real time with a high-spatial resolution (down to 2 μm) imposed by the periodicity of the post array. For these experiments, we use differentiated Madin-Darby canine kidney (MDCK) epithelial cells. Our data provide definite information on mechanical forces exerted by a cellular assembly. The maximum intensity of the forces is localized on the edge of the epithelia. Hepatocyte growth factor promotes cell motility and induces strong scattering activity of MDCK cells. Thus, we compare forces generated by MDCK cells in subconfluent epithelia versus isolated cells after hepatocyte growth factor treatment. Maximal-traction stresses at the edge of a monolayer correspond to higher values than those measured for a single cell and may be due to a collective behavior. PMID:15695588

  9. Modeling cell migration in 3D: Status and challenges.

    PubMed

    Rangarajan, Rajagopal; Zaman, Muhammad H

    2008-01-01

    Cell migration is a multi-scale process that integrates signaling, mechanics and biochemical reaction kinetics. Various mathematical models accurately predict cell migration on 2D surfaces, but are unable to capture the complexities of 3D migration. Additionally, quantitative 3D cell migration models have been few and far between. In this review we look and characterize various mathematical models available in literature to predict cell migration in 3D matrices and analyze their strengths and possible changes to these models that could improve their predictive capabilities.

  10. Flow-driven cell migration under external electric fields

    PubMed Central

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

    2016-01-01

    Electric fields influence many aspects of cell physiology, including various forms of cell migration. Many cells are sensitive to electric fields, and can migrate toward a cathode or an anode, depending on the cell type. In this paper, 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. PMID:26765031

  11. 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.

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

    PubMed

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

    2016-08-18

    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.

  13. 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

  14. Guided migration of neural stem cells derived from human embryonic stem cells by an electric field.

    PubMed

    Feng, Jun-Feng; Liu, Jing; Zhang, Xiu-Zhen; Zhang, Lei; Jiang, Ji-Yao; Nolta, Jan; Zhao, Min

    2012-02-01

    Small direct current (DC) electric fields (EFs) guide neurite growth and migration of rodent neural stem cells (NSCs). However, this could be species dependent. Therefore, it is critical to investigate how human NSCs (hNSCs) respond to EF before any possible clinical attempt. Aiming to characterize the EF-stimulated and guided migration of hNSCs, we derived hNSCs from a well-established human embryonic stem cell line H9. Small applied DC EFs, as low as 16 mV/mm, induced significant directional migration toward the cathode. Reversal of the field polarity reversed migration of hNSCs. The galvanotactic/electrotactic response was both time and voltage dependent. The migration directedness and distance to the cathode increased with the increase of field strength. (Rho-kinase) inhibitor Y27632 is used to enhance viability of stem cells and has previously been reported to inhibit EF-guided directional migration in induced pluripotent stem cells and neurons. However, its presence did not significantly affect the directionality of hNSC migration in an EF. Cytokine receptor [C-X-C chemokine receptor type 4 (CXCR4)] is important for chemotaxis of NSCs in the brain. The blockage of CXCR4 did not affect the electrotaxis of hNSCs. We conclude that hNSCs respond to a small EF by directional migration. Applied EFs could potentially be further exploited to guide hNSCs to injured sites in the central nervous system to improve the outcome of various diseases.

  15. 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.

  16. 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.

  17. Fine Tuning Cell Migration by a Disintegrin and Metalloproteinases

    PubMed Central

    Theodorou, K.

    2017-01-01

    Cell migration is an instrumental process involved in organ development, tissue homeostasis, and various physiological processes and also in numerous pathologies. Both basic cell migration and migration towards chemotactic stimulus consist of changes in cell polarity and cytoskeletal rearrangement, cell detachment from, invasion through, and reattachment to their neighboring cells, and numerous interactions with the extracellular matrix. The different steps of immune cell, tissue cell, or cancer cell migration are tightly coordinated in time and place by growth factors, cytokines/chemokines, adhesion molecules, and receptors for these ligands. This review describes how a disintegrin and metalloproteinases interfere with several steps of cell migration, either by proteolytic cleavage of such molecules or by functions independent of proteolytic activity. PMID:28260841

  18. 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.

  19. 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.

  20. Rapamycin promotes Schwann cell migration and nerve growth factor secretion

    PubMed Central

    Liu, Fang; Zhang, Haiwei; Zhang, Kaiming; Wang, Xinyu; Li, Shipu; Yin, Yixia

    2014-01-01

    Rapamycin, similar to FK506, can promote neural regeneration in vitro. We assumed that the mechanisms of action of rapamycin and FK506 in promoting peripheral nerve regeneration were similar. This study compared the effects of different concentrations of rapamycin and FK506 on Schwann cells and investigated effects and mechanisms of rapamycin on improving peripheral nerve regeneration. Results demonstrated that the lowest rapamycin concentration (1.53 nmol/L) more significantly promoted Schwann cell migration than the highest FK506 concentration (100μmol/L). Rapamycin promoted the secretion of nerve growth factors and upregulated growth-associated protein 43 expression in Schwann cells, but did not significantly affect Schwann cell proliferation. Therefore, rapamycin has potential application in peripheral nerve regeneration therapy. PMID:25206862

  1. 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

  2. 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.

  3. 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

  4. Lutein Inhibits the Migration of Retinal Pigment Epithelial Cells via Cytosolic and Mitochondrial Akt Pathways (Lutein Inhibits RPE Cells Migration)

    PubMed Central

    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

    2014-01-01

    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. PMID:25110866

  5. 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.

  6. The planar cell polarity pathway directs parietal endoderm migration.

    PubMed

    LaMonica, Kristi; Bass, Maya; Grabel, Laura

    2009-06-01

    Parietal endoderm (PE) contributes to the yolk sac and is the first migratory cell type in the mammalian embryo. We can visualize PE migration in vitro using the F9 teratocarcinoma derived embryoid body outgrowth system and, show here that PE migration is directed by the non-canonical Wnt planar cell polarity (PCP) pathway via Rho/ROCK. Based on golgi apparatus localization and microtubule orientation, 68.6% of cells in control outgrowths are oriented in the direction of migration. Perturbation of Wnt signaling via sFRP treatment results in a loss of orientation coupled with an increase in cell migration. Inhibition of the PCP pathway at the level of Daam1 also results in a loss of cell orientation along with an increase in cell migration, as seen with sFRP treatment. Constitutively active Daam can inhibit the loss of orientation that occurs with sFRP treatment. We previously demonstrated that ROCK inhibition leads to an increase in cell migration, and we now show that these cells also lack oriented migration. Canonical Wnt signaling or the Rac arm of the PCP pathway does not appear to play a role in PE oriented migration. These data suggest the PCP pathway via Rho/ROCK modulates migration of PE.

  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. A ring barrier-based migration assay to assess cell migration in vitro.

    PubMed

    Das, Asha M; Eggermont, Alexander M M; ten Hagen, Timo L M

    2015-06-01

    Cell migration is a key feature of virtually every biological process, and it can be studied in a variety of ways. Here we outline a protocol for the in vitro study of cell migration using a ring barrier-based assay. A 'barrier' is inserted in the culture chamber, which prevents cells from entering a defined area. Cells of interest are seeded around this barrier, and after the formation of a peripheral monolayer the barrier is removed and migration into the cell-free area is monitored. This assay is highly reproducible and convenient to perform, and it allows the deduction of several parameters of migration, including total and effective migration, velocity and cell polarization. An advantage of this assay over the conventional scratch assay is that the cells move over an unaltered and virgin surface, and thus the effect of matrix components on cell migration can be studied. In addition, the cells are not harmed at the onset of the assay. Through computer automation, four individual barrier assays can be monitored at the same time. The procedure can be used in a 12-well standard plate allowing higher throughput, or it can be modified to perform invasion assays. The basic procedure takes 2-3 d to complete.

  9. 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.

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

    PubMed Central

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

    2015-01-01

    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

  11. Heterologous cells cooperate to augment stem cell migration, homing, and engraftment.

    PubMed

    Adams, Gregor B; Chabner, Karissa T; Foxall, Russell B; Weibrecht, Kathryn W; Rodrigues, Neil P; Dombkowski, David; Fallon, Robert; Poznansky, Mark C; Scadden, David T

    2003-01-01

    T-lymphocyte depletion of bone marrow grafts compromises engraftment, suggesting a facilitating mechanism provided by the T cells that has been shown to associate with CD8(+) but not CD4(+) T cells. Explanations for this phenomenon have focused on immune targeting of residual host cells or cytokine production. We provide evidence for an alternative mechanism based on cooperative effects on cell motility. We observed that engraftment of CD34(+) cells in a beta(2)-microglobulin-deficient nonobese diabetic/severe combined immunodeficiency (beta(2)m(-/-) NOD/SCID) mouse model paralleled clinical observations in humans, with an enhancing effect noted from the addition of CD8(+) cells but not CD4(+) cells. This correlated with CD8(+) augmentation of CD34(+) cell homing to the bone marrow in vivo and CD8(+) cell-associated increases of CD34(+) cell transmigration through a bone marrow endothelial cell line in vitro. The cooperative interaction was not sensitive to brefeldin A inhibition of protein secretion. However, cytochalasin D-induced inhibition of CD8(+) cytoskeletal rearrangements abrogated CD34(+) transendothelial migration and impaired CD34(+) cell homing in vivo. CD8(+) cells did not migrate in tandem with CD34(+) cells or alter endothelial barrier integrity; rather, they affected phosphotyrosine-mediated signaling in CD34(+) cells in response to the chemokine stromal derived factor-1alpha (SDF-1alpha). These data demonstrate cell-cell cooperativity between different cell types in mediating chemotactic events and provide one potential explanation for the clinically observed effect of CD8(+) cells on bone marrow transplantation. This modification of cell migration by neighboring cells provides broad possibilities for combinatorial effects between cells of different types to influence cell localization.

  12. 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.

  13. Tumor cell migration screen identifies SRPK1 as breast cancer metastasis determinant.

    PubMed

    van Roosmalen, Wies; Le Dévédec, Sylvia E; Golani, Ofra; Smid, Marcel; Pulyakhina, Irina; Timmermans, Annemieke M; Look, Maxime P; Zi, Di; Pont, Chantal; de Graauw, Marjo; Naffar-Abu-Amara, Suha; Kirsanova, Catherine; Rustici, Gabriella; Hoen, Peter A C 't; Martens, John W M; Foekens, John A; Geiger, Benjamin; van de Water, Bob

    2015-04-01

    Tumor cell migration is a key process for cancer cell dissemination and metastasis that is controlled by signal-mediated cytoskeletal and cell matrix adhesion remodeling. Using a phagokinetic track assay with migratory H1299 cells, we performed an siRNA screen of almost 1,500 genes encoding kinases/phosphatases and adhesome- and migration-related proteins to identify genes that affect tumor cell migration speed and persistence. Thirty candidate genes that altered cell migration were validated in live tumor cell migration assays. Eight were associated with metastasis-free survival in breast cancer patients, with integrin β3-binding protein (ITGB3BP), MAP3K8, NIMA-related kinase (NEK2), and SHC-transforming protein 1 (SHC1) being the most predictive. Examination of genes that modulate migration indicated that SRPK1, encoding the splicing factor kinase SRSF protein kinase 1, is relevant to breast cancer outcomes, as it was highly expressed in basal breast cancer. Furthermore, high SRPK1 expression correlated with poor breast cancer disease outcome and preferential metastasis to the lungs and brain. In 2 independent murine models of breast tumor metastasis, stable shRNA-based SRPK1 knockdown suppressed metastasis to distant organs, including lung, liver, and spleen, and inhibited focal adhesion reorganization. Our study provides comprehensive information on the molecular determinants of tumor cell migration and suggests that SRPK1 has potential as a drug target for limiting breast cancer metastasis.

  14. Tumor cell migration screen identifies SRPK1 as breast cancer metastasis determinant

    PubMed Central

    van Roosmalen, Wies; Le Dévédec, Sylvia E.; Golani, Ofra; Smid, Marcel; Pulyakhina, Irina; Timmermans, Annemieke M.; Look, Maxime P.; Zi, Di; Pont, Chantal; de Graauw, Marjo; Naffar-Abu-Amara, Suha; Kirsanova, Catherine; Rustici, Gabriella; Hoen, Peter A.C. ‘t; Martens, John W.M.; Foekens, John A.; Geiger, Benjamin; van de Water, Bob

    2015-01-01

    Tumor cell migration is a key process for cancer cell dissemination and metastasis that is controlled by signal-mediated cytoskeletal and cell matrix adhesion remodeling. Using a phagokinetic track assay with migratory H1299 cells, we performed an siRNA screen of almost 1,500 genes encoding kinases/phosphatases and adhesome- and migration-related proteins to identify genes that affect tumor cell migration speed and persistence. Thirty candidate genes that altered cell migration were validated in live tumor cell migration assays. Eight were associated with metastasis-free survival in breast cancer patients, with integrin β3–binding protein (ITGB3BP), MAP3K8, NIMA-related kinase (NEK2), and SHC-transforming protein 1 (SHC1) being the most predictive. Examination of genes that modulate migration indicated that SRPK1, encoding the splicing factor kinase SRSF protein kinase 1, is relevant to breast cancer outcomes, as it was highly expressed in basal breast cancer. Furthermore, high SRPK1 expression correlated with poor breast cancer disease outcome and preferential metastasis to the lungs and brain. In 2 independent murine models of breast tumor metastasis, stable shRNA-based SRPK1 knockdown suppressed metastasis to distant organs, including lung, liver, and spleen, and inhibited focal adhesion reorganization. Our study provides comprehensive information on the molecular determinants of tumor cell migration and suggests that SRPK1 has potential as a drug target for limiting breast cancer metastasis. PMID:25774502

  15. 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.

  16. AP-2α inhibits hepatocellular carcinoma cell growth and migration.

    PubMed

    Huang, Wenhuan; Chen, Cheng; Liang, Zhongheng; Qiu, Junlu; Li, Xinxin; Hu, Xiang; Xiang, Shuanglin; Ding, Xiaofeng; Zhang, Jian

    2016-03-01

    Transcription factor AP-2α is involved in many types of human cancers, but its role in hepatocellular carcinogenesis is largely unknown. In this study, we found that expression of AP-2α was low in 40% of human hepatocellular cancers compared with adjacent normal tissues by immunohistochemical analysis. Moreover, AP-2α expression was low or absent in hepatocellular cancer cell lines (HepG2, Hep3B, SMMC-7721 and MHHC 97-H). Human liver cancer cell lines SMMC-7721 and Hep3B stably overexpressing AP-2α were established by lentiviral infection and puromycin screening, and the ectopic expression of AP-2α was able to inhibit hepatocellular cancer cell growth and proliferation by cell viability, MTT assay and liquid colony formation in vitro and in vivo. Furthermore, AP-2α overexpression decreased liver cancer cell migration and invasion as assessed by wound healing and Transwell assays, increasing the sensitivity of liver cancer cells to cisplatin analyzed by MTT assays. Also AP-2α overexpression suppressed the sphere formation and renewed the ability of cancer stem cells. Finally, we found that AP-2α is epigenetically modified and modulates the levels of phosphorylated extracellular signal-regulated protein kinase (ERK), β-catenin, p53, EMT, and CD133 expression in liver cancer cell lines. These results suggested that AP-2α expression is low in human hepatocellular cancers by regulating multiple signaling to affect hepatocellular cancer cell growth and migration. Therefore, AP-2α might represent a novel potential target in human hepatocellular cancer therapy.

  17. 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  19. Cell surface beta 1,4-galactosyltransferase functions during neural crest cell migration and neurulation in vivo

    PubMed Central

    1992-01-01

    Mesenchymal cell migration and neurite outgrowth are mediated in part by binding of cell surface beta 1,4-galactosyltransferase (GalTase) to N-linked oligosaccharides within the E8 domain of laminin. In this study, we determined whether cell surface GalTase functions during neural crest cell migration and neural development in vivo using antibodies raised against affinity-purified chicken serum GalTase. The antibodies specifically recognized two embryonic proteins of 77 and 67 kD, both of which express GalTase activity. The antibodies also immunoprecipitated and inhibited chick embryo GalTase activity, and inhibited neural crest cell migration on laminin matrices in vitro. Anti-GalTase antibodies were microinjected into the head mesenchyme of stage 7-9 chick embryos or cranial to Henson's node of stage 6 embryos. Anti-avian GalTase IgG decreased cranial neural crest cell migration on the injected side but did not cross the embryonic midline and did not affect neural crest cell migration on the uninjected side. Anti-avian GalTase Fab crossed the embryonic midline and perturbed cranial neural crest cell migration throughout the head. Neural fold elevation and neural tube closure were also disrupted by Fab fragments. Cell surface GalTase was localized to migrating neural crest cells and to the basal surfaces of neural epithelia by indirect immunofluorescence, whereas GalTase was undetectable on neural crest cells prior to migration. These results suggest that, during early embryogenesis, cell surface GalTase participates during neural crest cell migration, perhaps by interacting with laminin, a major component of the basal lamina. Cell surface GalTase also appears to play a role in neural tube formation, possibly by mediating neural epithelial adhesion to the underlying basal lamina. PMID:1560031

  20. Suppression of Calpain Expression by NSAIDs is Associated with Inhibition of Cell Migration in Rat Duodenum.

    PubMed

    Silver, Kristopher; Littlejohn, A; Thomas, Laurel; Bawa, Bhupinder; Lillich, James D

    2017-03-22

    Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used for the alleviation of pain and inflammation, but these drugs are also associated with a suite of negative side effects. Gastrointestinal (GI) toxicity is particularly concerning since it affects an estimated 70% of individuals taking NSAIDs routinely, and evidence suggests the majority of toxicity is occurring in the small intestine. Traditionally, NSAID-induced GI toxicity has been associated with indiscriminate inhibition of cyclooxygenase isoforms, but other mechanisms, including inhibition of cell migration, intestinal restitution, and wound healing, are likely to contribute to toxicity. Previous efforts demonstrated that treatment of cultured intestinal epithelial cells (IEC) with NSAIDs inhibits expression and activity of calpain proteases, but the effects of specific inhibition of calpain expression in vitro or the effects of NSAIDs on intestinal cell migration in vivo remain to be determined. Accordingly, we examined the effect of suppression of calpain protease expression with siRNA on cell migration in cultured IECs and evaluated the effects of NSAID treatment on epithelial cell migration and calpain protease expression in rat duodenum. Our results show that calpain siRNA inhibits protease expression and slows migration in cultured IECs. Additionally, NSAID treatment of rats slowed migration up the villus axis and suppressed calpain expression in duodenal epithelial cells. Our results are supportive of the hypothesis that suppression of calpain expression leading to slowing of cell migration is a potential mechanism through which NSAIDs cause GI toxicity.

  1. Dependence of sea urchin primary mesenchyme cell migration on xyloside- and sulfate-sensitive cell surface-associated components.

    PubMed

    Lane, M C; Solursh, M

    1988-05-01

    The migration of sea urchin primary mesenchyme cells (PMC) is inhibited in embryos cultured in sulfate-free seawater and in seawater containing exogenous xylosides. In the present study, primary mesenchyme cells and extra-cellular matrix have been isolated from normal and treated Lytechinus pictus and Strongylocentrotus purpuratus embryos and recombined in an in vitro migration assay to determine whether the cells or the matrix are migration defective. Normal cells were found to migrate on either normal or treated matrix, whereas sulfate-deprived and xyloside-treated PMC failed to migrate in vitro on normal and treated substrata. Migratory ability can be restored to defective cells by returning the PMC to normal seawater, or by exposing the defective cells to materials removed from the surface of normal cells with 1 M urea. The similarity of the results obtained with sulfate-deprived and xyloside-treated PMC suggested that a common molecule may be affected by the two treatments. As a first test of this possibility, xyloside-treated S. purpuratus PMC were given the urea extract prepared from sulfate-deprived S. purpuratus PMC, and this extract did not restore migratory ability. These findings indicate that PMC normally synthesize a surface-associated molecule that is involved in cell migration, and the sensitivity to exogenous xylosides and sulfate deprivation suggests that a sulfated proteoglycan may be involved in primary mesenchyme cell migration.

  2. Regulation of cell migration via the EGFR signaling pathway in oral squamous cell carcinoma cells

    PubMed Central

    Ohnishi, Yuichi; Yasui, Hiroki; Kakudo, Kenji; Nozaki, Masami

    2017-01-01

    Cell migration potency is essential in cancer metastasis and is often regulated by extracellular stimuli. Oral squamous cell carcinoma cell lines include those that are sensitive, as well as resistant, to the effects of the epidermal growth factor receptor (EGFR) inhibitor cetuximab on cell migration. In the present study, the molecular differences in the EGFR response to cell migration between the SAS cetuximab-sensitive and HSC4 cetuximab-resistant cell lines was examined. Treatment with the EGFR inhibitors AG1478 and cetuximab reduced the migration potency of SAS cells, but not HSC4 cells. The migration of the two cell lines was inhibited under serum-free culture conditions, and the addition of EGF to the serum-free medium promoted the migration of SAS cells, but not HSC4 cells. In addition, SAS cell migration was reduced by the mitogen-activated protein kinase kinase and protein kinase B (Akt) inhibitors PD98059 and MK2206, whereas HSC4 cell migration was only inhibited by MK2206. EGF induced an increase in extracellular signal-regulated kinase phosphorylation levels in HSC4 cells, and stimulated Akt phosphorylation levels in SAS cells. Furthermore, the staining of actin filaments with phalloidin was significantly increased by the inhibition of EGFR in SAS cells, but was not observed as altered in HSC4 cells. Conversely, the addition of EGF to the culture medium decreased the accumulation of actin filaments in SAS cells. The results suggest that the EGF-EGFR signaling pathway has an important role in SAS cell migration via the modulation of actin dynamics, and that HSC4 cell migration is regulated by a serum component other than EGFR.

  3. Role of cortactin homolog HS1 in transendothelial migration of natural killer cells.

    PubMed

    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.

  4. Functional transcriptomics of a migrating cell in Caenorhabditis elegans.

    PubMed

    Schwarz, Erich M; Kato, Mihoko; Sternberg, Paul W

    2012-10-02

    In both metazoan development and metastatic cancer, migrating cells must carry out a detailed, complex program of sensing cues, binding substrates, and moving their cytoskeletons. The linker cell in Caenorhabditis elegans males undergoes a stereotyped migration that guides gonad organogenesis, occurs with precise timing, and requires the nuclear hormone receptor NHR-67. To better understand how this occurs, we performed RNA-seq of individually staged and dissected linker cells, comparing transcriptomes from linker cells of third-stage (L3) larvae, fourth-stage (L4) larvae, and nhr-67-RNAi-treated L4 larvae. We observed expression of 8,000-10,000 genes in the linker cell, 22-25% of which were up- or down-regulated 20-fold during development by NHR-67. Of genes that we tested by RNAi, 22% (45 of 204) were required for normal shape and migration, suggesting that many NHR-67-dependent, linker cell-enriched genes play roles in this migration. One unexpected class of genes up-regulated by NHR-67 was tandem pore potassium channels, which are required for normal linker-cell migration. We also found phenotypes for genes with human orthologs but no previously described migratory function. Our results provide an extensive catalog of genes that act in a migrating cell, identify unique molecular functions involved in nematode cell migration, and suggest similar functions in humans.

  5. Molecular signatures of cell migration in C. elegans Q neuroblasts

    PubMed Central

    Ou, Guangshuo

    2009-01-01

    Metazoan cell movement has been studied extensively in vitro, but cell migration in living animals is much less well understood. In this report, we have studied the Caenorhabditis elegans Q neuroblast lineage during larval development, developing live animal imaging methods for following neuroblast migration with single cell resolution. We find that each of the Q descendants migrates at different speeds and for distinct distances. By quantitative green fluorescent protein imaging, we find that Q descendants that migrate faster and longer than their sisters up-regulate protein levels of MIG-2, a Rho family guanosine triphosphatase, and/or down-regulate INA-1, an integrin α subunit, during migration. We also show that Q neuroblasts bearing mutations in either MIG-2 or INA-1 migrate at reduced speeds. The migration defect of the mig-2 mutants, but not ina-1, appears to result from a lack of persistent polarization in the direction of cell migration. Thus, MIG-2 and INA-1 function distinctly to control Q neuroblast migration in living C. elegans. PMID:19349580

  6. Nanomechanical measurement of adhesion and migration of leukemia cells with phorbol 12-myristate 13-acetate treatment.

    PubMed

    Zhou, Zhuo Long; Ma, Jing; Tong, Ming-Hui; Chan, Barbara Pui; Wong, Alice Sze Tsai; Ngan, Alfonso Hing Wan

    The adhesion and traction behavior of leukemia cells in their microenvironment is directly linked to their migration, which is a prime issue affecting the release of cancer cells from the bone marrow and hence metastasis. In assessing the effectiveness of phorbol 12-myristate 13-acetate (PMA) treatment, the conventional batch-cell transwell-migration assay may not indicate the intrinsic effect of the treatment on migration, since the treatment may also affect other cellular behavior, such as proliferation or death. In this study, the pN-level adhesion and traction forces between single leukemia cells and their microenvironment were directly measured using optical tweezers and traction-force microscopy. The effects of PMA on K562 and THP1 leukemia cells were studied, and the results showed that PMA treatment significantly increased cell adhesion with extracellular matrix proteins, bone marrow stromal cells, and human fibroblasts. PMA treatment also significantly increased the traction of THP1 cells on bovine serum albumin proteins, although the effect on K562 cells was insignificant. Western blots showed an increased expression of E-cadherin and vimentin proteins after the leukemia cells were treated with PMA. The study suggests that PMA upregulates adhesion and thus suppresses the migration of both K562 and THP1 cells in their microenvironment. The ability of optical tweezers and traction-force microscopy to measure directly pN-level cell-protein or cell-cell contact was also demonstrated.

  7. S-Fms signalobody enhances myeloid cell growth and migration.

    PubMed

    Kawahara, Masahiro; Hitomi, Azusa; Nagamune, Teruyuki

    2014-07-01

    Since receptor tyrosine kinases (RTKs) control various cell fates in many types of cells, mimicry of RTK functions is promising for artificial control of cell fates. We have previously developed single-chain Fv (scFv)/receptor chimeras named signalobodies that can mimic receptor signaling in response to a specific antigen. While the RTK-based signalobodies enabled us to control cell growth and migration, further extension of applicability in another cell type would underlie the impact of the RTK-based signalobodies. In this study, we applied the scFv-c-Fms (S-Fms) signalobody in a murine myeloid progenitor cell line, FDC-P1. S-Fms transduced a fluorescein-conjugated BSA (BSA-FL)-dependent growth signal and activated downstream signaling molecules including MEK, ERK, Akt, and STAT3, which are major constituents of Ras/MAPK, PI3K/Akt, and JAK/STAT signaling pathways. In addition, S-Fms transduced a migration signal as demonstrated by the transwell-based migration assay. Direct real-time observation of the cells further confirmed that FDC/S-Fms cells underwent directional cell migration toward a positive gradient of BSA-FL. These results demonstrated the utility of the S-Fms signalobody for controlling growth and migration of myeloid cells. Further extension of our approach includes economical large-scale production of practically relevant blood cells as well as artificial control of cell migration for tissue regeneration and immune response.

  8. Analysis of primary cilia in directional cell migration in fibroblasts.

    PubMed

    Christensen, Søren T; Veland, Iben R; Schwab, Albrecht; Cammer, Michael; Satir, Peter

    2013-01-01

    Early studies of migrating fibroblasts showed that primary cilia orient in front of the nucleus and point toward the leading edge. Recent work has shown that primary cilia coordinate a series of signaling pathways critical to fibroblast cell migration during development and in wound healing. In particular, platelet-derived growth factor receptor alpha (PDGFRα) is compartmentalized to the primary cilium to activate signaling pathways that regulate reorganization of the cytoskeleton required for lamellipodium formation and directional migration in the presence of a specific ligand gradient. We summarize selected methods in analyzing ciliary function in directional cell migration, including immunofluorescence microscopy, scratch assay, and chemotaxis assay by micropipette addition of PDGFRα ligands to cultures of fibroblasts. These methods should be useful not only in studying cell migration but also more generally in delineating response pathways in cells with primary cilia.

  9. Cancer cell motility: lessons from migration in confined spaces

    PubMed Central

    Paul, Colin D.; Mistriotis, Panagiotis; Konstantopoulos, Konstantinos

    2017-01-01

    Time-lapse, deep-tissue imaging made possible by advances in intravital microscopy has demonstrated the importance of tumour cell migration through confining tracks in vivo. These tracks may either be endogenous features of tissues or be created by tumour or tumour-associated cells. Importantly, migration mechanisms through confining microenvironments are not predicted by 2D migration assays. Engineered in vitro models have been used to delineate the mechanisms of cell motility through confining spaces encountered in vivo. Understanding cancer cell locomotion through physiologically relevant confining tracks could be useful in developing therapeutic strategies to combat metastasis. PMID:27909339

  10. Cancer cell motility: lessons from migration in confined spaces.

    PubMed

    Paul, Colin D; Mistriotis, Panagiotis; Konstantopoulos, Konstantinos

    2017-02-01

    Time-lapse, deep-tissue imaging made possible by advances in intravital microscopy has demonstrated the importance of tumour cell migration through confining tracks in vivo. These tracks may either be endogenous features of tissues or be created by tumour or tumour-associated cells. Importantly, migration mechanisms through confining microenvironments are not predicted by 2D migration assays. Engineered in vitro models have been used to delineate the mechanisms of cell motility through confining spaces encountered in vivo. Understanding cancer cell locomotion through physiologically relevant confining tracks could be useful in developing therapeutic strategies to combat metastasis.

  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. 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.

  13. Alkylindole-sensitive receptors modulate microglial cell migration and proliferation

    PubMed Central

    Fung, Susan; Cherry, Allison E.; Xu, Cong; Stella, Nephi

    2015-01-01

    Ligands targeting G protein-coupled receptors (GPCR) expressed by microglia have been shown to regulate distinct components of their activation process, including cell proliferation, migration and differentiation into M1 or M2 phenotypes. Cannabinoids, including the active component of the Cannabis plant, tetrahydrocannabinol (THC), and the synthetic alkylindole (AI) compound, WIN55212-2 (WIN-2), activate two molecularly identified GPCRs: CB1 and CB2. Previous studies reported that WIN-2 activates an additional unknown GPCR that is not activated by plant-derived cannabinoids, and evidence indicates that microglia express these receptors. Detailed studies on the role of AI-sensitive receptors in microglial cell activation were difficult as no selective pharmacological tools were available. Here, three newly-developed AI analogues allowed us to determine if microglia express AI-sensitive receptors and if so, study how they regulate the microglial cell activation process. We found that mouse microglia in primary culture express functional AI-sensitive receptors as measured by radioligand binding and changes in intracellular cAMP levels, and that these receptors control both basal and ATP-stimulated migration. AI analogues inhibit cell proliferation stimulated by macrophage-colony stimulating factor (M-CSF) without affecting basal cell proliferation. Remarkably, AI analogues do not control the expression of effector proteins characteristic of M1 or M2 phenotypes; yet activating microglia with M1 and M2 cytokines reduces the microglial response to AI analogues. Our results suggest that microglia express functional AI-sensitive receptors that control select components of their activation process. Agonists of these novel targets might represent a novel class of therapeutics to influence the microglial cell activation process. PMID:25914169

  14. Microgrooved Polymer Substrates Promote Collective Cell Migration To Accelerate Fracture Healing in an in Vitro Model.

    PubMed

    Zhang, Qing; Dong, Hua; Li, Yuli; Zhu, Ye; Zeng, Lei; Gao, Huichang; Yuan, Bo; Chen, Xiaofeng; Mao, Chuanbin

    2015-10-21

    Surface topography can affect cell adhesion, morphology, polarity, cytoskeleton organization, and osteogenesis. However, little is known about the effect of topography on the fracture healing in repairing nonunion and large bone defects. Microgrooved topography on the surface of bone implants may promote cell migration into the fracture gap to accelerate fracture healing. To prove this hypothesis, we used an in vitro fracture (wound) healing assay on the microgrooved polycaprolactone substrates to study the effect of microgroove widths and depths on the osteoblast-like cell (MG-63) migration and the subsequent healing. We found that the microgrooved substrates promoted MG-63 cells to migrate collectively into the wound gap, which serves as a fracture model, along the grooves and ridges as compared with the flat substrates. Moreover, the groove widths did not show obvious influence on the wound healing whereas the smaller groove depths tended to favor the collective cell migration and thus subsequent healing. The microgrooved substrates accelerated the wound healing by facilitating the collective cell migration into the wound gaps but not by promoting the cell proliferation. Furthermore, microgrooves were also found to promote the migration of human mesenchymal stem cells (hMSCs) to heal the fracture model. Though osteogenic differentiation of hMSCs was not improved on the microgrooved substrate, collagen I and minerals deposited by hMSCs were organized in a way similar to those in the extracellular matrix of natural bone. These findings suggest the necessity in using microgrooved implants in enhancing fracture healing in bone repair.

  15. Protein kinase Cepsilon is important for migration of neuroblastoma cells

    PubMed Central

    Stensman, Helena; Larsson, Christer

    2008-01-01

    Background Migration is important for the metastatic capacity and thus for the malignancy of cancer cells. There is limited knowledge on regulatory factors that promote the migration of neuroblastoma cells. This study investigates the hypothesis that protein kinase C (PKC) isoforms regulate neuroblastoma cell motility. Methods PKC isoforms were downregulated with siRNA or modulated with activators and inhibitors. Migration was analyzed with scratch and transwell assays. Protein phosphorylation and expression levels were measured with Western blot. Results Stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) induced migration of SK-N-BE(2)C neuroblastoma cells. Treatment with the general protein kinase C (PKC) inhibitor GF109203X and the inhibitor of classical isoforms Gö6976 inhibited migration while an inhibitor of PKCβ isoforms did not have an effect. Downregulation of PKCε, but not of PKCα or PKCδ, with siRNA led to a suppression of both basal and TPA-stimulated migration. Experiments using PD98059 and LY294002, inhibitors of the Erk and phosphatidylinositol 3-kinase (PI3K) pathways, respectively, showed that PI3K is not necessary for TPA-induced migration. The Erk pathway might be involved in TPA-induced migration but not in migration driven by PKCε. TPA induced phosphorylation of the PKC substrate myristoylated alanine-rich C kinase substrate (MARCKS) which was suppressed by the PKC inhibitors. Treatment with siRNA oligonucleotides against different PKC isoforms before stimulation with TPA did not influence the phosphorylation of MARCKS. Conclusion PKCε is important for migration of SK-N-BE(2)C neuroblastoma cells. Neither the Erk pathway nor MARCKS are critical downstream targets of PKCε but they may be involved in TPA-mediated migration. PMID:19077250

  16. Proliferating cells in suborbital tissue drive eye migration in flatfish.

    PubMed

    Bao, Baolong; Ke, Zhonghe; Xing, Jubin; Peatman, Eric; Liu, Zhanjiang; Xie, Caixia; Xu, Bing; Gai, Junwei; Gong, Xiaoling; Yang, Guimei; Jiang, Yan; Tang, Wenqiao; Ren, Daming

    2011-03-01

    The left/right asymmetry of adult flatfishes (Pleuronectiformes) is remarkable given the external body symmetry of the larval fish. The best-known change is the migration of their eyes: one eye migrates from one side to the other. Two extinct primitive pleuronectiformes with incomplete orbital migration have again attracted public attention to the mechanism of eye migration, a subject of speculation and research for over a century. Cranial asymmetry is currently believed to be responsible for eye migration. Contrary to that hypothesis, we show here that the initial migration of the eye is caused by cell proliferation in the suborbital tissue of the blind side and that the twist of frontal bone is dependent on eye migration. The inhibition of cell proliferation in the suborbital area of the blind side by microinjected colchicine was able to prevent eye migration and, thereafter, cranial asymmetry in juvenile Solea senegalensis (right sideness, Soleidae), Cynoglossus semilaevis (left sideness, Cynoglossidae), and Paralichthys olivaceus (left sideness, Paralichthyidae) with a bottom-dwelling lifestyle. Our results correct the current misunderstanding that eye migration is driven by the cranial asymmetry and simplify the explanation for broken left/right eye-symmetry. Our findings should help to focus the search on eye migration-related genes associated with cell proliferation. Finally, a novel model is proposed in this research which provides a reasonable explanation for differences in the migrating eye between, and sometimes within, different species of flatfish and which should aid in our overall understanding of eye migration in the ontogenesis and evolution of Pleuronectiformes.

  17. Nanomechanical measurement of adhesion and migration of leukemia cells with phorbol 12-myristate 13-acetate treatment

    PubMed Central

    Zhou, Zhuo Long; Ma, Jing; Tong, Ming-Hui; Chan, Barbara Pui; Wong, Alice Sze Tsai; Ngan, Alfonso Hing Wan

    2016-01-01

    The adhesion and traction behavior of leukemia cells in their microenvironment is directly linked to their migration, which is a prime issue affecting the release of cancer cells from the bone marrow and hence metastasis. In assessing the effectiveness of phorbol 12-myristate 13-acetate (PMA) treatment, the conventional batch-cell transwell-migration assay may not indicate the intrinsic effect of the treatment on migration, since the treatment may also affect other cellular behavior, such as proliferation or death. In this study, the pN-level adhesion and traction forces between single leukemia cells and their microenvironment were directly measured using optical tweezers and traction-force microscopy. The effects of PMA on K562 and THP1 leukemia cells were studied, and the results showed that PMA treatment significantly increased cell adhesion with extracellular matrix proteins, bone marrow stromal cells, and human fibroblasts. PMA treatment also significantly increased the traction of THP1 cells on bovine serum albumin proteins, although the effect on K562 cells was insignificant. Western blots showed an increased expression of E-cadherin and vimentin proteins after the leukemia cells were treated with PMA. The study suggests that PMA upregulates adhesion and thus suppresses the migration of both K562 and THP1 cells in their microenvironment. The ability of optical tweezers and traction-force microscopy to measure directly pN-level cell–protein or cell–cell contact was also demonstrated. PMID:27994457

  18. miR-186 affects the proliferation, invasion and migration of human gastric cancer by inhibition of Twist1

    PubMed Central

    Cao, Chunhong; Sun, Deguang; Zhang, Liang; Song, Lei

    2016-01-01

    Recent evidence shows that miRNAs are dysregulated in a variety of cancers including gastric cancer (GC), and emerging as key oncogenes or tumor suppressors. In this study, qRT-PCR was used to analyze the expression of miR-186 in GC tissues and adjacent non-cancerous tissues, and then more in-vitro experiments were used to investigate the role of miR-186 in GC cells. Here, we identified miR-186 was generally down-regulated in GC tissues; however, Twist1 was generally up-regulated in GC tissues. Moreover, miR-186 and Twist1 were associated with larger tumor size and advanced clinical stage of GC. In-vitro experiments demonstrated that ectopic overexpression of miR-186 inhibited GC cell proliferation, invasion and migration; however, inhibited expression of miR-186 enhanced cell proliferation, invasion and migration. Furthermore, the luciferase reporter assay demonstrated Twist1 as a direct target of miR-186. Finally, over-expression of Twist1 abrogated inhibitory impact of miR-186 on cell proliferation, invasion and migration. In conclusion, miR-186 affects the proliferation, invasion and migration of human gastric cancer by inhibition of Twist1, and could be a tumor suppressor in GC development. Thus, miR-186 may be served as a candidate prognostic biomarker and target for new therapies in human gastric cancer. PMID:27835599

  19. Factors affecting migration of vanillin from chitosan/methyl cellulose films.

    PubMed

    Sangsuwan, J; Rattanapanone, N; Auras, R A; Harte, B R; Rachtanapun, P

    2009-09-01

    The diffusion kinetics and factors affecting the migration of vanillin from chitosan/methyl cellulose (Chi/MC) films into water, cantaloupe juice (CJ), pineapple juice (PJ), and citrate buffer adjusted to pH values of 3.5, 5, and 6.5 were studied. Vanillin was incorporated into the Chi/MC films to provide an inhibitory effect against microorganisms. Initial vanillin concentration in the films, temperature, and pH of extracting solvent impacted the migration behavior of vanillin. The diffusion coefficients (D) followed the Arrhenius equation and increased as temperature increased for all the solvents. As temperature rose, the rate increment of the diffusion of vanillin into pineapple juice was higher than that into water and cantaloupe juice. Films containing lower vanillin content had a higher diffusion coefficient than those containing high vanillin content. Migration of vanillin was affected by pH rather than acid concentration. Lower pH resulted in a higher migration rate.

  20. 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

  1. Regulatory T Cells from Colon Cancer Patients Inhibit Effector T-cell Migration through an Adenosine-Dependent Mechanism.

    PubMed

    Sundström, Patrik; Stenstad, Hanna; Langenes, Veronica; Ahlmanner, Filip; Theander, Lisa; Ndah, Tapuka Gordon; Fredin, Kamilla; Börjesson, Lars; Gustavsson, Bengt; Bastid, Jérémy; Quiding-Järbrink, Marianne

    2016-03-01

    T cell-mediated immunity is a major component of antitumor immunity. In order to be efficient, effector T cells must leave the circulation and enter into the tumor tissue. Regulatory T cells (Treg) from gastric cancer patients, but not from healthy volunteers, potently inhibit migration of conventional T cells through activated endothelium. In this study, we compared T cells from colon cancer patients and healthy donors to determine the mechanisms used by Tregs from cancer patients to inhibit conventional T-cell migration. Our results showed that circulating Tregs from cancer patients expressed high levels of CD39, an ectoenzyme mediating hydrolysis of ATP to AMP, as a rate-determining first step in the generation of immunosuppressive adenosine. Tumor-associated Tregs expressed even more CD39, and we therefore examined the importance of adenosine in Treg-mediated inhibition of T-cell transendothelial migration in vitro. Exogenous adenosine significantly reduced migration of conventional T cells from healthy volunteers, and blocking either adenosine receptors or CD39 enzymatic activity during transmigration restored the ability of conventional T cells from cancer patients to migrate. Adenosine did not directly affect T cells or endothelial cells, but reduced the ability of monocytes to activate the endothelium. Taken together, our results indicate that Treg-derived adenosine acts on monocytes and contributes to reduced transendothelial migration of effector T cells into tumors. This effect of Tregs is specific for cancer patients, and our results indicate that Tregs may affect not only T-cell effector functions but also their migration into tumors.

  2. HOW JOB CHARACTERISTICS AFFECT INTERNATIONAL MIGRATION: THE ROLE OF INFORMALITY IN MEXICO

    PubMed Central

    Blanchard, Sarah

    2016-01-01

    Despite the importance given to employment opportunities as a primary motive for migration, previous studies have paid insufficient attention to the kinds of jobs that are more likely to retain workers in their countries of origin. We use information from a panel survey of Mexican adults to examine how job characteristics affect the risk of international migration. The sampling strategy and overall size of the survey allow us to analyze the effect of employment characteristics on migration from urban areas, which have much greater labor market diversity, and to separate our analysis by gender. We also distinguish migrants according to whether they migrate for work or for other reasons. We find informality to be a significant predictor of international migration. Even after controlling for individual factors including workers’ wages, as well as various household- and community-level predictors, we find that workers employed in the informal sector have significantly higher odds of migrating than their counterparts in the formal sector. The pervasive nature of informality in many developing countries from which a high proportion of international migrants originate may therefore create a constant supply of workers who are predisposed to migrate. Our findings thus have important implications for a proper understanding of the effects of economic development on migration. PMID:23073750

  3. How job characteristics affect international migration: the role of informality in Mexico.

    PubMed

    Villarreal, Andrés; Blanchard, Sarah

    2013-04-01

    Despite the importance given to employment opportunities as a primary motive for migration, previous studies have paid insufficient attention to the kinds of jobs that are more likely to retain workers in their countries of origin. We use information from a panel survey of Mexican adults to examine how job characteristics affect the risk of international migration. The sampling strategy and overall size of the survey allow us to analyze the effect of employment characteristics on migration from urban areas, which have much greater labor market diversity, and to separate our analysis by gender. We also distinguish migrants according to whether they migrate for work or for other reasons. We find informality to be a significant predictor of international migration. Even after controlling for individual factors including workers' wages, as well as various household- and community-level predictors, we find that workers employed in the informal sector have significantly higher odds of migrating than their counterparts in the formal sector. The pervasive nature of informality in many developing countries from which a high proportion of international migrants originate may therefore create a constant supply of workers who are predisposed to migrate. Our findings thus have important implications for a proper understanding of the effects of economic development on migration.

  4. Propagating Waves of Directionality and Coordination Orchestrate Collective Cell Migration

    PubMed Central

    Zaritsky, Assaf; Kaplan, Doron; Hecht, Inbal; Natan, Sari; Wolf, Lior; Gov, Nir S.; Ben-Jacob, Eshel; Tsarfaty, Ilan

    2014-01-01

    The ability of cells to coordinately migrate in groups is crucial to enable them to travel long distances during embryonic development, wound healing and tumorigenesis, but the fundamental mechanisms underlying intercellular coordination during collective cell migration remain elusive despite considerable research efforts. A novel analytical framework is introduced here to explicitly detect and quantify cell clusters that move coordinately in a monolayer. The analysis combines and associates vast amount of spatiotemporal data across multiple experiments into transparent quantitative measures to report the emergence of new modes of organized behavior during collective migration of tumor and epithelial cells in wound healing assays. First, we discovered the emergence of a wave of coordinated migration propagating backward from the wound front, which reflects formation of clusters of coordinately migrating cells that are generated further away from the wound edge and disintegrate close to the advancing front. This wave emerges in both normal and tumor cells, and is amplified by Met activation with hepatocyte growth factor/scatter factor. Second, Met activation was found to induce coinciding waves of cellular acceleration and stretching, which in turn trigger the emergence of a backward propagating wave of directional migration with about an hour phase lag. Assessments of the relations between the waves revealed that amplified coordinated migration is associated with the emergence of directional migration. Taken together, our data and simplified modeling-based assessments suggest that increased velocity leads to enhanced coordination: higher motility arises due to acceleration and stretching that seems to increase directionality by temporarily diminishing the velocity components orthogonal to the direction defined by the monolayer geometry. Spatial and temporal accumulation of directionality thus defines coordination. The findings offer new insight and suggest a basic

  5. 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).

  6. Emerging role for nuclear rotation and orientation in cell migration

    PubMed Central

    Maninová, Miloslava; Iwanicki, Marcin P; Vomastek, Tomáš

    2014-01-01

    Nucleus movement, positioning, and orientation is precisely specified and actively regulated within cells, and it plays a critical role in many cellular and developmental processes. Mutation of proteins that regulate the nucleus anchoring and movement lead to diverse pathologies, laminopathies in particular, suggesting that the nucleus correct positioning and movement is essential for proper cellular function. In motile cells that polarize toward the direction of migration, the nucleus undergoes controlled rotation promoting the alignment of the nucleus with the axis of migration. Such spatial organization of the cell appears to be optimal for the cell migration. Nuclear reorientation requires the cytoskeleton to be anchored to the nuclear envelope, which exerts pulling or pushing torque on the nucleus. Here we discuss the possible molecular mechanisms regulating the nuclear rotation and reorientation and the significance of this type of nuclear movement for cell migration. PMID:24589621

  7. 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

  8. Cell-cell interactions stabilize emerging collective migration modes

    NASA Astrophysics Data System (ADS)

    Parker, Joshua; Guven, Can; Wang, Chenlu; Ott, Ed; Losert, Wolfgang

    2014-03-01

    We propose a coarse-grained mechanistic model for simulating the dynamics of the biological model organism Dictyostelium discoideum, incorporating gradient sensing, random motility via actin protrusions, persistent random motion and signal relay. We demonstrate that our simple cell model does result in the macroscopic group migration patterns seen in no-flow gradient chambers, namely a transition from individual motion to multi-cell ``streaming'' to aggregation as the external signal is decreased. We also find that cell-cell adhesion further stabilizes the contact network independent of chemical signaling, suggesting no indirect feedback between mechanical forces and gradient sensing. We discuss further modifications to the model and as well as further applications to quantifying dynamics using spatio-temporal contact networks. Co-first author

  9. Bimodal Analysis of Mammary Epithelial Cell Migration in Two Dimensions

    PubMed Central

    Potdar, Alka A.; Lu, Jenny; Jeon, Junhwan; Weaver, Alissa M.; Cummings, Peter T.

    2013-01-01

    Cell migration paths of mammary epithelial cells (expressing different versions of the promigratory tyrosine kinase receptor Her2/Neu) were analyzed within a bimodal framework that is a generalization of the run-and-tumble description applicable to bacterial migration. The mammalian cell trajectories were segregated into two types of alternating modes, namely, the “directional-mode” (mode I, the more persistent mode, analogous to the bacterial run phase) and the “re-orientation-mode” (mode II, the less persistent mode, analogous to the bacterial tumble phase). Higher resolution (more pixel information, relative to cell size) and smaller sampling intervals (time between images) were found to give a better estimate of the deduced single cell dynamics (such as directional-mode time and turn angle distribution) of the various cell types from the bimodal analysis. The bimodal analysis tool permits the deduction of short-time dynamics of cell motion such as the turn angle distributions and turn frequencies during the course of cell migration compared to standard methods of cell migration analysis. We find that the two-hour mammalian cell tracking data do not fall into the diffusive regime implying that the often-used random motility expressions for mammalian cell motion (based on assuming diffusive motion) are invalid over the time steps (fraction of minute) typically used in modeling mammalian cell migration. PMID:18982450

  10. Pertussis Toxin Is a Robust and Selective Inhibitor of High Grade Glioma Cell Migration and Invasion

    PubMed Central

    Wang, Lei; Natali, Letizia; Karimi-Mostowfi, Nicki; Brifault, Coralie; Gonias, Steven L.

    2016-01-01

    In high grade glioma (HGG), extensive tumor cell infiltration of normal brain typically precludes identifying effective margins for surgical resection or irradiation. Pertussis toxin (PT) is a multimeric complex that inactivates diverse Gi/o G-protein coupled receptors (GPCRs). Despite the broad continuum of regulatory events controlled by GPCRs, PT may be applicable as a therapeutic. We have shown that the urokinase receptor (uPAR) is a major driver of HGG cell migration. uPAR-initiated cell-signaling requires a Gi/o GPCR, N-formyl Peptide Receptor 2 (FPR2), as an essential co-receptor and is thus, PT-sensitive. Herein, we show that PT robustly inhibits migration of three separate HGG-like cell lines that express a mutated form of the EGF Receptor (EGFR), EGFRvIII, which is constitutively active. PT also almost completely blocked the ability of HGG cells to invade Matrigel. In the equivalent concentration range (0.01–1.0 μg/mL), PT had no effect on cell survival and only affected proliferation of one cell line. Neutralization of EGFRvIII expression in HGG cells, which is known to activate uPAR-initiated cell-signaling, promoted HGG cell migration. The increase in HGG cell migration, induced by EGFRvIII neutralization, was entirely blocked by silencing FPR2 gene expression or by treating the cells with PT. When U87MG HGG cells were cultured as suspended neurospheres in serum-free, growth factor-supplemented medium, uPAR expression was increased. HGG cells isolated from neurospheres migrated through Transwell membranes without loss of cell contacts; this process was inhibited by PT by >90%. PT also inhibited expression of vimentin by HGG cells; vimentin is associated with epithelial-mesenchymal transition and worsened prognosis. We conclude that PT may function as a selective inhibitor of HGG cell migration and invasion. PMID:27977780

  11. 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.

  12. Microscopy assays for evaluation of mast cell migration and chemotaxis.

    PubMed

    Bambousková, Monika; Hájková, Zuzana; Dráber, Pavel; Dráber, Petr

    2014-01-01

    A better understanding of the molecular mechanisms leading to mast cell migration and chemotaxis is the long-term goal in mast cell research and is essential for comprehension of mast cell function in health and disease. Various techniques have been developed in recent decades for in vitro and in vivo assessment of mast cell motility and chemotaxis. In this chapter three microscopy assays facilitating real-time quantification of mast cell chemotaxis and migration are described, focusing on individual cell tracking and data analysis.

  13. Inhibitory effects of novel SphK2 inhibitors on migration of cancer cells.

    PubMed

    Jung, Deokho; Jung, Junghyun; Lee, Euiyeon; Mok, Chang Soo; Jeon, Hyunjin; Park, Chang Seo; Jang, Wonhee; Kwon, Youngeun

    2017-02-13

    Cell migration is an essential process for survival and differentiation of mammalian cells. Numerous diseases are induced or influenced by inappropriate regulation of cell migration, which plays a key role in cancer cell metastasis. In fact, very few anti-metastasis drugs are available on the market. SphKs are enzymes that convert sphingosine to sphingosine-1- phosphate (S1P) and are known to control various cellular functions, including migration of cells. Among two human isozymes of SphK2, SphK2 is known to promote apoptosis, suppresses cell growth, and controls cell migration; in addition, the specific ablation of SphK2 activity was reported to inhibit cancer cell metastasis. The previously identified SG12 and SG14 are synthetic analogs of sphingoid, natural inhibitors of SphKs, and can specifically inhibit the functions of SphK2. In this paper, we investigated how SG12 and SG14 affect cell migration by monitoring both cumulative and individual cell migration behavior using HeLa cells. SG12 and SG14 mutually showed stronger inhibitory effects with less cytotoxicity compared with a general SphK inhibitor, N,N-dimethylsphingosine (DMS). The mechanistic aspects of specific SphK2 inhibition were studied by examining actin filamentation as well as the expression levels of motility-related genes. The data revealed that SG12 and SG14 resemble DMS in decreasing overall cell motility, but differ in that they differentially affect motility parameters and motility-related signal transduction pathways and therefore actin polymerization, which are not altered by DMS. Our findings show that SphK2 inhibitors are putative candidates for anti-metastatic drugs.

  14. 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. Targeting Epithelial Cell Migration to Accelerate Wound Healing

    DTIC Science & Technology

    2012-02-01

    consisting of the proteins Rsu1, Integrin Linked Kinase (ILK), PINCH, and Parvin. The correct association of these proteins in a functional complex...impacting integrin function and actin polymerization. 15. SUBJECT TERMS Wound healing, cell migration, protein kinase C, protein kinase A 16. SECURITY...epithelial cell migration in wound healing. In addition, the correct association of these proteins in a functional complex depends on their phosphorylation

  2. Targeting Epithelial Cell Migration to Accelerate Wound Healing

    DTIC Science & Technology

    2010-12-01

    the protein kinase C (PKC) family and the process can be enhanced or inhibited by modulating the levels of the RIPP complex proteins as well by...HACAT cells indicates that PKC may modulate migration on two-dimensional surface. 15. SUBJECT TERMS Wound healing, cell migration, protein kinase C ...ABSTRACT U c . THIS PAGE U UU 11 19b. TELEPHONE NUMBER (include area code) Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. Z39.18

  3. Bioelectric Field Enhancement: The Influence on Membrane Potential and Cell Migration In Vitro

    PubMed Central

    Purnell, Marcy C.; Skrinjar, Terence J.

    2016-01-01

    Objective: The extracellular matrix consists of critical components that affect fibroblast polarization and migration. The existence of both intrinsic and extrinsic electrical signals that play essential roles in the development, physiology, regeneration, and pathology of cells was discovered over a century ago. In this study, we study how the Bioelectric Field Enhancement (BEFE) device and its generated electromagnetic field (EMF) by continuous direct current (DC) significantly affect the membrane potential and cell migration of fibroblasts in vitro. Approach: This is an experimental analysis of membrane potential and cell migration of murine fibroblasts when grown in treated media that has been reconstituted with an aqueous solution that has been exposed to an EMF, which is generated by this device versus fibroblasts grown in identically prepared control media that has not been exposed to the EMF. Results: The growth of fibroblasts in the treated media shows a strong percent change in polarization of the plasma membrane and significant increase in cell migration compared to control groups. Innovation: These experiments show the potential for an adjunct wound care therapy using a continuous DC EMF application through a medium of water. Conclusion: Growth media that was reconstituted with an aqueous solution that had been exposed to this DC derived EMF shows significant changes in cell polarity and cell migration of fibroblasts in vitro. The BEFE device has shown enhanced chronic wound healing in anecdotal reports from patients globally for decades when used as a footbath/bath and could lead to a novel EMF application in wound healing. PMID:28078187

  4. Exploration of molecular pathways mediating electric field-directed Schwann cell migration by RNA-Seq

    PubMed Central

    Yao, Li; Li, Yongchao; Knapp, Jennifer; Smith, Peter

    2015-01-01

    In peripheral nervous systems, Schwann cells wrap around axons of motor and sensory neurons to form the myelin sheath. Following spinal cord injury, Schwann cells regenerate and migrate to the lesion and are involved in the spinal cord regeneration process. Transplantation of Schwann cells into injured neural tissue results in enhanced spinal axonal regeneration. Effective directional migration of Schwann cells is critical in the neural regeneration process. In this study, we report that Schwann cells migrate anodally in an applied electric field (EF). The directedness and displacement of anodal migration increased significantly when the strength of the EF increased from 50 mV/mm to 200 mV/mm. The EF did not significantly affect the cell migration speed. To explore the genes and signaling pathways that regulate cell migration in EFs, we performed a comparative analysis of differential gene expression between cells stimulated with an EF (100 mV/mm) and those without using next-generation RNA sequencing, verified by RT-qPCR. Based on the cut-off criteria (FC > 1.2, q < 0.05), we identified 1,045 up-regulated and 1,636 down-regulated genes in control cells versus EF-stimulated cells. A Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis found that compared to the control group, 21 pathways are down-regulated, while 10 pathways are up-regulated. Differentially expressed genes participate in multiple cellular signaling pathways involved in the regulation of cell migration, including pathways of regulation of actin cytoskeleton, focal adhesion, and PI3K-Akt. PMID:25557037

  5. Surgical Marking Pen Dye Inhibits Saphenous Vein Cell Proliferation and Migration in Saphenous Vein Graft Tissue

    PubMed Central

    Kikuchi, Shinsuke; Kenagy, Richard D; Gao, Lu; Wight, Thomas N; Azuma, Nobuyoshi; Sobel, Michael; Clowes, Alexander W

    2014-01-01

    Objective Markers containing dyes such as crystal violet (CAS 548-62-9) are routinely used on the adventitia of vein bypass grafts to avoid twisting during placement. Since little is known about how these dyes affect vein graft healing and function, we determined the effect of crystal violet on cell migration and proliferation, which are responses to injury after grafting. Methods Fresh human saphenous veins were obtained as residual specimens from leg bypass surgeries. Portions of the vein that had been surgically marked with crystal violet were analyzed separately from those that had no dye marking. In the laboratory, they were split into easily dissected inner and outer layers after removal of endothelium. This f cleavage plane was within the circular muscle layer of the media. Cell migration from explants was measured daily as either 1) % migration positive explants, which exclusively measures migration, or 2) the number of cells on the plastic surrounding each explant, which measures migration plus proliferation. Cell proliferation and apoptosis (Ki67 and TUNEL staining, respectively) were determined in dye-marked and unmarked areas of cultured vein rings. The dose-dependent effects of crystal violet were measured for cell migration from explants as well as proliferation, migration, and death of cultured outer layer cells. Dye was extracted from explants with ethanol and quantified by spectrophotometry. Results There was significantly less cell migration from visibly blue, compared to unstained, outer layer explants by both methods. There was no significant difference in migration from inner layer explants adjacent to blue-stained or unstained sections of vein, because dye did not penetrate to the inner layer. Ki67 staining of vein in organ culture, which is a measure of proliferation, progressively increased up to 6 days in non-blue outer layer and was abolished in the blue outer layer. Evidence of apoptosis (TUNEL staining) was present throughout the wall

  6. Gradient biomaterials and their influences on cell migration

    PubMed Central

    Wu, Jindan; Mao, Zhengwei; Tan, Huaping; Han, Lulu; Ren, Tanchen; Gao, Changyou

    2012-01-01

    Cell migration participates in a variety of physiological and pathological processes such as embryonic development, cancer metastasis, blood vessel formation and remoulding, tissue regeneration, immune surveillance and inflammation. The cells specifically migrate to destiny sites induced by the gradually varying concentration (gradient) of soluble signal factors and the ligands bound with the extracellular matrix in the body during a wound healing process. Therefore, regulation of the cell migration behaviours is of paramount importance in regenerative medicine. One important way is to create a microenvironment that mimics the in vivo cellular and tissue complexity by incorporating physical, chemical and biological signal gradients into engineered biomaterials. In this review, the gradients existing in vivo and their influences on cell migration are briefly described. Recent developments in the fabrication of gradient biomaterials for controlling cellular behaviours, especially the cell migration, are summarized, highlighting the importance of the intrinsic driving mechanism for tissue regeneration and the design principle of complicated and advanced tissue regenerative materials. The potential uses of the gradient biomaterials in regenerative medicine are introduced. The current and future trends in gradient biomaterials and programmed cell migration in terms of the long-term goals of tissue regeneration are prospected. PMID:23741610

  7. Activation of the δ-opioid receptor promotes cutaneous wound healing by affecting keratinocyte intercellular adhesion and migration

    PubMed Central

    Bigliardi, P L; Neumann, C; Teo, Y L; Pant, A; Bigliardi-Qi, M

    2015-01-01

    BACKGROUND AND PURPOSE In addition to its analgesic functions, the peripheral opioid receptor system affects skin homeostasis by influencing cell differentiation, migration and adhesion; also, wound healing is altered in δ-opioid receptor knockout mice (DOPr–/–). Hence, we investigated δ-opioid receptor effects on the expression of several proteins of the desmosomal junction complex and on the migratory behaviour of keratinocytes. EXPERIMENTAL APPROACH Expression levels of desmosomal cadherins in wild-type and DOPr–/– mice, and the morphology of intercellular adhesion in human keratinocytes were analysed by immunofluorescence. To investigate the δ-opioid receptor activation pathway, protein expression was studied using Western blot and its effect on cellular migration determined by in vitro live cell migration recordings from human keratinocytes. KEY RESULTS Expression of the desmosomal cadherins, desmogleins 1 and 4, was up-regulated in skin from DOPr–/– mice, and down-regulated in δ-opioid receptor-overexpressing human keratinocytes. The localization of desmoplakin expression was rearranged from linear arrays emanating from cell borders to puncta in cell periphery, resulting in less stable intercellular adhesion. Migration and wound recovery were enhanced in human keratinocyte monolayers overexpressing δ-opioid receptors in vitro. These δ-opioid receptor effects were antagonized by specific PKCα/β inhibition indicating they were mediated through the PKC signalling pathway. Finally, cells overexpressing δ-opioid receptors developed characteristically long but undirected protrusions containing filamentous actin and δ-opioid receptors, indicating an enhanced migratory phenotype. CONCLUSION AND IMPLICATIONS Opioid receptors affect intercellular adhesion and wound healing mechanisms, underlining the importance of a cutaneous neuroendocrine system in wound healing and skin homeostasis. LINKED ARTICLES This article is part of a themed section on

  8. 3D printing of biomimetic microstructures for cancer cell migration.

    PubMed

    Huang, Tina Qing; Qu, Xin; Liu, Justin; Chen, Shaochen

    2014-02-01

    To understand the physical behavior and migration of cancer cells, a 3D in vitro micro-chip in hydrogel was created using 3D projection printing. The micro-chip has a honeycomb branched structure, aiming to mimic 3D vascular morphology to test, monitor, and analyze differences in the behavior of cancer cells (i.e. HeLa) vs. non-cancerous cell lines (i.e. 10 T1/2). The 3D Projection Printing system can fabricate complex structures in seconds from user-created designs. The fabricated microstructures have three different channel widths of 25, 45, and 120 microns wide to reflect a range of blood vessel diameters. HeLa and 10 T1/2 cells seeded within the micro-chip were then analyzed for morphology and cell migration speed. 10 T1/2 cells exhibited greater changes in morphology due to channel size width than HeLa cells; however, channel width had a limited effect on 10 T1/2 cell migration while HeLa cancer cell migration increased as channel width decreased. This physiologically relevant 3D cancer tissue model has the potential to be a powerful tool for future drug discoveries and cancer migration studies.

  9. 3D printing of biomimetic microstructures for cancer cell migration

    PubMed Central

    Huang, Tina Qing; Qu, Xin; Liu, Justin; Chen, Shaochen

    2013-01-01

    To understand the physical behavior and migration of cancer cells, a 3D in vitro micro-chip in hydrogel was created using 3D projection printing. The micro-chip has a honeycomb branched structure, aiming to mimic 3D vascular morphology to test, monitor, and analyze differences in the behavior of cancer cells (i.e. HeLa) vs. non-cancerous cell lines (i.e. 10T1/2). The 3D Projection Printing system can fabricate complex structures in seconds from user-created designs. The fabricated microstructures have three different channel widths of 25, 45, and 120 microns wide to reflect a range of blood vessel diameters. HeLa and 10T1/2 cells seeded within the micro-chip were then analyzed for morphology and cell migration speed. 10T1/2 cells exhibited greater changes in morphology due to channel size width than HeLa cells; however, channel width had a limited effect on 10T1/2 cell migration while HeLa cancer cell migration increased as channel width decreased. This physiologically relevant 3D cancer tissue model has the potential to be a powerful tool for future drug discoveries and cancer migration studies PMID:24150602

  10. Nucleus and nucleus-cytoskeleton connections in 3D cell migration.

    PubMed

    Liu, Lingling; Luo, Qing; Sun, Jinghui; Song, Guanbin

    2016-10-15

    Cell migration plays an important role in many physiological and pathological settings, ranging from embryonic development to cancer metastasis. Currently, accumulating data suggest that cells migrating in three-dimensional (3D) environments show well-defined differences compared to their well-established two-dimensional (2D) counterparts. During 3D migration, the cell body and nucleus must deform to allow cellular passage through the available spaces, and the deformability of the relatively rigid nucleus may constitute a limiting step. Here, we highlight the key evidence regarding the role of the nuclear mechanics in 3D migration, including the molecular components that govern the stiffness of the nucleus and review how the nuclear dynamics are connected to and controlled by cytoskeleton-based migration machinery. Intriguingly, nuclear movement must be coordinated with the cytoskeletal dynamics at the leading and trailing edges, which in turn impact the cytoplasmic dynamics that affect the migration efficiency. Thus, we suggest that alterations in the nuclear structure may facilitate cellular reorganizations that are necessary for efficient migration.

  11. 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.

  12. Effects of SOX2 on Proliferation, Migration and Adhesion of Human Dental Pulp Stem Cells.

    PubMed

    Liu, Pengfei; Cai, Jinglei; Dong, Delu; Chen, Yaoyu; Liu, Xiaobo; Wang, Yi; Zhou, Yulai

    2015-01-01

    As a key factor for cell pluripotent and self-renewing phenotypes, SOX2 has attracted scientists' attention gradually in recent years. However, its exact effects in dental pulp stem cells (DPSCs) are still unclear. In this study, we mainly investigated whether SOX2 could affect some biological functions of DPSCs. DPSCs were isolated from the dental pulp of human impacted third molar. SOX2 overexpressing DPSCs (DPSCs-SOX2) were established through retroviral infection. The effect of SOX2 on cell proliferation, migration and adhesion ability was evaluated with CCK-8, trans-well system and fibronectin-induced cell attachment experiment respectively. Whole genome expression of DPSCs-SOX2 was analyzed with RNA microarray. Furthermore, a rescue experiment was performed with SOX2-siRNA in DPSC-SOX2 to confirm the effect of SOX2 overexpression in DPSCs. We found that SOX2 overexpression could result in the enhancement of cell proliferation, migration, and adhesion in DPSCs obviously. RNA microarray analysis indicated that some key genes in the signal pathways associated with cell cycle, migration and adhesion were upregulated in different degree, and the results were further confirmed with qPCR and western-blot. Finally, DPSC-SOX2 transfected with SOX2-siRNA showed a decrease of cell proliferation, migration and adhesion ability, which further confirmed the biological effect of SOX2 in human DPSCs. This study indicated that SOX2 could improve the cell proliferation, migration and adhesion ability of DPSCs through regulating gene expression about cell cycle, migration and adhesion, and provided a novel strategy to develop seed cells with strong proliferation, migration and adhesion ability for tissue engineering.

  13. Random migration contributes to cytotoxicity of activated CD8+ T-lymphocytes but not NK cells.

    PubMed

    Onishi, Hideya; Kiyota, Akifumi; Koya, Norihiro; Tanaka, Hiroto; Umebayashi, Masayo; Katano, Mitsuo; Morisaki, Takashi

    2014-08-01

    Activated lymphocytes have the ability to undergo non-directional cell movement known as random migration, although the biological role for this remains unclear. Herein, we investigated how random migration affects cytotoxicity of activated lymphocytes using time-lapse imaging analysis. The kinetics of random migration paralleled cytotoxicity in activated lymphocytes. Sphingosine-1-phosphate (S1P) and its receptor-1 (S1PR1) play an important role in lymphocyte migration. Phosphorylated FTY720 (FTYP), a structural analog of S1P, significantly inhibited random migration and cytotoxicity of activated CD3(+)NKG2D(+)CD8(+) T-lymphocytes but not CD3(-)NKG2D(+)CD56(+) natural killer (NK) cells. In a mouse xenograft model, FTYP-treated activated lymphocytes exhibited lower cytotoxicity and less tumor infiltration for activated CD3(+)NKG2D(+) T-lymphocytes but not CD3(-)NKG2D(+) NK cells. These results suggest that random migration contributes to the cytotoxicity of activated CD8(+) T-cells but not of NK cells.

  14. 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.

  15. 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.

  16. Galvanotactic migration of EA.Hy926 endothelial cells in a novel designed electric field bioreactor.

    PubMed

    Long, Haiyan; Yang, Gang; Wang, Zhengrong

    2011-12-01

    Endogenous direct current electric fields (dcEFs) play a significant role in major biological processes such as embryogenesis, wound healing, and tissue regeneration. In this study, the galvanotaxis of human umbilical vein endothelial cell line EA.Hy926 was investigated by using a novel designed bioreactor. The physical features of the bioreactor were discussed and analyzed by both numerical simulation method and equivalent circuit model method. EA.Hy926 cells were cultured in the bioreactor for 10-24 h under 50-250 mV/mm dcEFs. Cell migration direction, distance, and velocity were recorded under an online time-lapse microscope. The effects of serum and growth factor on cell galvanotatic migration were investigated. To further explore the role of dcEFs in regulating endothelial cells, we analyzed the endothelial cell proliferation and secretion of nitric oxide (NO), endothelin-1 (ET-1) in response to dcEFs of physiological strength. Our results showed that EA.Hy926 cells had an obvious directional migration to the cathode, and the EF-directed migration was voltage dependent. The results also showed dcEFs did not affect cell proliferation, but affected the productions of NO and ET-1. Our study also showed the novel bioreactor, with a compact and planar style, makes it more convenient and more reasonable for EF stimulation experiments than earlier chamber designs.

  17. 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.

  18. Three-dimensional numerical model of cell morphology during migration in multi-signaling substrates.

    PubMed

    Mousavi, Seyed Jamaleddin; Doweidar, Mohamed Hamdy

    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

  19. 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

  20. Alk1 controls arterial endothelial cell migration in lumenized vessels.

    PubMed

    Rochon, Elizabeth R; Menon, Prahlad G; Roman, Beth L

    2016-07-15

    Heterozygous loss of the arterial-specific TGFβ type I receptor, activin receptor-like kinase 1 (ALK1; ACVRL1), causes hereditary hemorrhagic telangiectasia (HHT). HHT is characterized by development of fragile, direct connections between arteries and veins, or arteriovenous malformations (AVMs). However, how decreased ALK1 signaling leads to AVMs is unknown. To understand the cellular mis-steps that cause AVMs, we assessed endothelial cell behavior in alk1-deficient zebrafish embryos, which develop cranial AVMs. Our data demonstrate that alk1 loss has no effect on arterial endothelial cell proliferation but alters arterial endothelial cell migration within lumenized vessels. In wild-type embryos, alk1-positive cranial arterial endothelial cells generally migrate towards the heart, against the direction of blood flow, with some cells incorporating into endocardium. In alk1-deficient embryos, migration against flow is dampened and migration in the direction of flow is enhanced. Altered migration results in decreased endothelial cell number in arterial segments proximal to the heart and increased endothelial cell number in arterial segments distal to the heart. We speculate that the consequent increase in distal arterial caliber and hemodynamic load precipitates the flow-dependent development of downstream AVMs.

  1. Effects of TNF-alpha on Endothelial Cell Collective Migration

    NASA Astrophysics Data System (ADS)

    Chen, Desu; Wu, Di; Helim Aranda-Espinoza, Jose; Losert, Wolfgang

    2013-03-01

    Tumor necrosis factor (TNF-alpha) is a small cell-signaling protein usually released by monocytes and macrophages during an inflammatory response. Previous work had shown the effects of TNF-alpha on single cell morphology, migration, and biomechanical properties. However, the effect on collective migrations remains unexplored. In this work, we have created scratches on monolayers of human umbilical endothelial cells (HUVECs) treated with 25ng/mL TNF-alpha on glass substrates. The wound healing like processes were imaged with phase contrast microscopy. Quantitative analysis of the collective migration of cells treated with TNF-alpha indicates that these cells maintain their persistent motion and alignment better than untreated cells. In addition, the collective migration was characterized by measuring the amount of non-affine deformations of the wound healing monolayer. We found a lower mean non-affinity and narrower distribution of non-affinities upon TNF-alpha stimulation. These results suggest that TNF-alpha introduces a higher degree of organized cell collective migration.

  2. 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.

  3. Multiscale mechanisms of cell migration during development: theory and experiment.

    PubMed

    McLennan, Rebecca; Dyson, Louise; Prather, Katherine W; Morrison, Jason A; Baker, Ruth E; Maini, Philip K; Kulesa, Paul M

    2012-08-01

    Long-distance cell migration is an important feature of embryonic development, adult morphogenesis and cancer, yet the mechanisms that drive subpopulations of cells to distinct targets are poorly understood. Here, we use the embryonic neural crest (NC) in tandem with theoretical studies to evaluate model mechanisms of long-distance cell migration. We find that a simple chemotaxis model is insufficient to explain our experimental data. Instead, model simulations predict that NC cell migration requires leading cells to respond to long-range guidance signals and trailing cells to short-range cues in order to maintain a directed, multicellular stream. Experiments confirm differences in leading versus trailing NC cell subpopulations, manifested in unique cell orientation and gene expression patterns that respond to non-linear tissue growth of the migratory domain. Ablation experiments that delete the trailing NC cell subpopulation reveal that leading NC cells distribute all along the migratory pathway and develop a leading/trailing cellular orientation and gene expression profile that is predicted by model simulations. Transplantation experiments and model predictions that move trailing NC cells to the migratory front, or vice versa, reveal that cells adopt a gene expression profile and cell behaviors corresponding to the new position within the migratory stream. These results offer a mechanistic model in which leading cells create and respond to a cell-induced chemotactic gradient and transmit guidance information to trailing cells that use short-range signals to move in a directional manner.

  4. 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

  5. Cell density and actomyosin contractility control the organization of migrating collectives within an epithelium

    PubMed Central

    Loza, Andrew J.; Koride, Sarita; Schimizzi, Gregory V.; Li, Bo; Sun, Sean X.; Longmore, Gregory D.

    2016-01-01

    The mechanisms underlying collective migration are important for understanding development, wound healing, and tumor invasion. Here we focus on cell density to determine its role in collective migration. Our findings show that increasing cell density, as might be seen in cancer, transforms groups from broad collectives to small, narrow streams. Conversely, diminishing cell density, as might occur at a wound front, leads to large, broad collectives with a distinct leader–follower structure. Simulations identify force-sensitive contractility as a mediator of how density affects collectives, and guided by this prediction, we find that the baseline state of contractility can enhance or reduce organization. Finally, we test predictions from these data in an in vivo epithelium by using genetic manipulations to drive collective motion between predicted migratory phases. This work demonstrates how commonly altered cellular properties can prime groups of cells to adopt migration patterns that may be harnessed in health or exploited in disease. PMID:27605707

  6. Cell density and actomyosin contractility control the organization of migrating collectives within an epithelium.

    PubMed

    Loza, Andrew J; Koride, Sarita; Schimizzi, Gregory V; Li, Bo; Sun, Sean X; Longmore, Gregory D

    2016-11-07

    The mechanisms underlying collective migration are important for understanding development, wound healing, and tumor invasion. Here we focus on cell density to determine its role in collective migration. Our findings show that increasing cell density, as might be seen in cancer, transforms groups from broad collectives to small, narrow streams. Conversely, diminishing cell density, as might occur at a wound front, leads to large, broad collectives with a distinct leader-follower structure. Simulations identify force-sensitive contractility as a mediator of how density affects collectives, and guided by this prediction, we find that the baseline state of contractility can enhance or reduce organization. Finally, we test predictions from these data in an in vivo epithelium by using genetic manipulations to drive collective motion between predicted migratory phases. This work demonstrates how commonly altered cellular properties can prime groups of cells to adopt migration patterns that may be harnessed in health or exploited in disease.

  7. 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

  8. Nanog regulates primordial germ cell migration through Cxcr4b.

    PubMed

    Sánchez-Sánchez, Ana Virginia; Camp, Esther; Leal-Tassias, Aránzazu; Atkinson, Stuart P; Armstrong, Lyle; Díaz-Llopis, Manuel; Mullor, José L

    2010-09-01

    Gonadal development in vertebrates depends on the early determination of primordial germ cells (PGCs) and their correct migration to the sites where the gonads develop. Several genes have been implicated in PGC specification and migration in vertebrates. Additionally, some of the genes associated with pluripotency, such as Oct4 and Nanog, are expressed in PGCs and gonads, suggesting a role for these genes in maintaining pluripotency of the germ lineage, which may be considered the only cell type that perpetually maintains stemness properties. Here, we report that medaka Nanog (Ol-Nanog) is expressed in the developing PGCs. Depletion of Ol-Nanog protein causes aberrant migration of PGCs and inhibits expression of Cxcr4b in PGCs, where it normally serves as the receptor of Sdf1a to guide PGC migration. Moreover, chromatin immunoprecipitation analysis demonstrates that Ol-Nanog protein binds to the promoter region of Cxcr4b, suggesting a direct regulation of Cxcr4b by Ol-Nanog. Simultaneous overexpression of Cxcr4b mRNA and depletion of Ol-Nanog protein in PGCs rescues the migration defective phenotype induced by a loss of Ol-Nanog, whereas overexpression of Sdf1a, the ligand for Cxcr4b, does not restore proper PGC migration. These results indicate that Ol-Nanog mediates PGC migration by regulating Cxcr4b expression.

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

    PubMed

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

    2004-07-05

    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.

  10. 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

  11. 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

    2015-11-09

    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.

  12. Regulator of calcineurin 1 modulates cancer cell migration in vitro.

    PubMed

    Espinosa, Allan V; Shinohara, Motoo; Porchia, Leonardo M; Chung, Yun Jae; McCarty, Samantha; Saji, Motoyasu; Ringel, Matthew D

    2009-01-01

    Metastasis suppressors and other regulators of cell motility play an important role in tumor invasion and metastases. We previously identified that activation of the G protein coupled receptor 54 (GPR54) by the metastasis suppressor metastin inhibits cell migration in association with overexpression of Regulator of calcineurin 1 (RCAN1), an endogenous regulator of calcineurin. Calcineurin inhibitors also blocked cell migration in vitro and RCAN1 protein levels were reduced in nodal metastases in thyroid cancer. The purpose of the current study was to determine directly if RCAN1 functions as a motility suppressor in vitro. Several cancer cell lines derived from different cancer types with different motility rates were evaluated for RCAN1 expression levels. Using these systems we determined that reduction of endogenous RCAN1 using siRNA resulted in an increase in cancer cell motility while expression of exogenous RCAN1 reduced cell motility. In one cell line with a high migratory rate, the stability of exogenously expressed RCAN1 protein was reduced and was rescued by treatment with a proteasome inhibitor. Finally, overexpression of RCAN1 was associated with an increase in cell adhesion to collagen IV and reduced calcineurin activity. In summary, we have demonstrated that the expression of exogenous RCAN1 reduces migration and alters adhesion; and that the loss of endogenous RCAN1 leads to an increase in migration in the examined cancer cell lines. These results are consistent with a regulatory role for RCAN1 in cancer cell motility in vitro.

  13. Phenylboronic acid selectively inhibits human prostate and breast cancer cell migration and decreases viability.

    PubMed

    Bradke, Tiffany M; Hall, Casey; Carper, Stephen W; Plopper, George E

    2008-01-01

    We compared the in vitro effect of boric acid (BA) versus phenylboronic acid (PBA) on the migration of prostate and breast cancer cell lines and non-tumorigenic cells from the same tissues. Treatment at 24 hours with BA (< or =500 microM) did not inhibit chemotaxis on fibronectin in any cell line. However, treatment over the same time course with concentrations of PBA as low as 1 muM significantly inhibited cancer cell migration without effecting non-tumorigenic cell lines. The compounds did not affect cell adhesion or viability at 24 hours but did alter morphology; both decreased cancer cell viability at eight days. These results suggest that PBA is more potent than BA in targeting the metastatic and proliferative properties of cancer cells.

  14. 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

  15. Functional regulation of ClC-3 in the migration of vascular smooth muscle cells.

    PubMed

    Ganapathi, Sindura B; Wei, Shun-Guang; Zaremba, Angelika; Lamb, Fred S; Shears, Stephen B

    2013-01-01

    Migration of vascular smooth muscle cells (VSMCs) into neointima contributes to atherosclerosis and restenosis. This migration requires coordinated plasmalemmal fluxes of water and ions. Here, we show that aortic VSMC migration depends on the regulation of transmembrane Cl(-) flux by ClC-3, a Cl(-) channel/transporter. The contribution of ClC-3 to plasmalemmal Cl(-) current was studied in VSMCs by electrophysiological recordings. Cl(-) current was negligible in cells perfused with 0 [Ca(2+)]. Raising intracellular [Ca(2+)] to 0.5 μM activated a Cl(-) current (I(Cl.Ca)), approximately half of which was eliminated on inhibition by KN-93 of calmodulin-dependent protein kinase II. I(Cl.Ca) was also halved by inositol-3,4,5,6-tetrakisphosphate, a cellular signal with the biological function of specifically preventing calmodulin-dependent protein kinase II from activating I(Cl.Ca). Gene disruption of ClC-3 reduced I(Cl.Ca) by 50%. Moreover, I(Cl.Ca) in the ClC-3 null VSMCs was not affected by either KN-93 or inositol-3,4,5,6-tetrakisphosphate. We conclude that I(Cl.Ca) is composed of 2 components, one is ClC-3 independent whereas the other is ClC-3 dependent, activated by calmodulin-dependent protein kinase II and inhibited by inositol-3,4,5,6-tetrakisphosphate. We also assayed VSMC migration in transwell assays. Migration was halved in ClC-3 null cells versus wild-type cells. In addition, inhibition of ClC-3 by niflumic acid, KN-93, or inositol-3,4,5,6-tetrakisphosphate each reduced cell migration in wild-type cells but not in ClC-3 null cells. These cell-signaling roles of ClC-3 in VSMC migration suggest new therapeutic approaches to vascular remodeling diseases.

  16. RNase L is a negative regulator of cell migration.

    PubMed

    Banerjee, Shuvojit; Li, Geqiang; Li, Yize; Gaughan, Christina; Baskar, Danika; Parker, Yvonne; Lindner, Daniel J; Weiss, Susan R; Silverman, Robert H

    2015-12-29

    RNase L is a regulated endoribonuclease that functions in the interferon antiviral response. Activation of RNase L by 2', 5'-oligoadenylates has been linked to apoptosis, autophagy and inflammation. Genetic studies have also suggested the possible involvement of the RNase L gene (RNASEL) on chromosome 1q25.3 in several types of cancer. Here we report that ablation of RNase L in human prostate cancer PC3 cells by CRISPR/Cas9 gene editing technology enhanced cell migration as determined both by transwell assays and scratch wound healing assays. In addition, RNase L knockdown by means of RNAi increased migration of PC3 and DU145 cells in response to either fibronectin or serum stimulation, as did homozygous disruption of the RNase L gene in mouse embryonic fibroblasts. Serum or fibronectin stimulation of focal adhesion kinase (FAK) autophosphorylation on tyrosine-397 was increased by either knockdown or ablation of RNase L. In contrast, a missense mutant RNase L (R667A) lacking catalytic activity failed to suppress cell migration in PC3 cells. However, a nuclease-inactive mutant mouse RNase L (W630A) was able to partially inhibit migration of mouse fibroblasts. Consistent with a role for the catalytic activity of RNase L, transfection of PC3 cells with the RNase L activator, 2', 5'-oligoadenylate, suppressed cell migration. RNase L knockdown in PC3 cells enhanced tumor growth and metastasis following implantation in the mouse prostate. Our results suggest that naturally occurring mutations in the RNase L gene might promote enhanced cell migration and metastasis.

  17. RNase L is a negative regulator of cell migration

    PubMed Central

    Banerjee, Shuvojit; Li, Geqiang; Li, Yize; Gaughan, Christina; Baskar, Danika; Parker, Yvonne; Lindner, Daniel J.; Weiss, Susan R.; Silverman, Robert H.

    2015-01-01

    RNase L is a regulated endoribonuclease that functions in the interferon antiviral response. Activation of RNase L by 2′, 5′-oligoadenylates has been linked to apoptosis, autophagy and inflammation. Genetic studies have also suggested the possible involvement of the RNase L gene (RNASEL) on chromosome 1q25.3 in several types of cancer. Here we report that ablation of RNase L in human prostate cancer PC3 cells by CRISPR/Cas9 gene editing technology enhanced cell migration as determined both by transwell assays and scratch wound healing assays. In addition, RNase L knockdown by means of RNAi increased migration of PC3 and DU145 cells in response to either fibronectin or serum stimulation, as did homozygous disruption of the RNase L gene in mouse embryonic fibroblasts. Serum or fibronectin stimulation of focal adhesion kinase (FAK) autophosphorylation on tyrosine-397 was increased by either knockdown or ablation of RNase L. In contrast, a missense mutant RNase L (R667A) lacking catalytic activity failed to suppress cell migration in PC3 cells. However, a nuclease-inactive mutant mouse RNase L (W630A) was able to partially inhibit migration of mouse fibroblasts. Consistent with a role for the catalytic activity of RNase L, transfection of PC3 cells with the RNase L activator, 2′, 5′-oligoadenylate, suppressed cell migration. RNase L knockdown in PC3 cells enhanced tumor growth and metastasis following implantation in the mouse prostate. Our results suggest that naturally occurring mutations in the RNase L gene might promote enhanced cell migration and metastasis. PMID:26517238

  18. 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.

  19. DNA Damage Follows Repair Factor Depletion and Portends Genome Variation in Cancer Cells after Pore Migration.

    PubMed

    Irianto, Jerome; Xia, Yuntao; Pfeifer, Charlotte R; Athirasala, Avathamsa; Ji, Jiazheng; Alvey, Cory; Tewari, Manu; Bennett, Rachel R; Harding, Shane M; Liu, Andrea J; Greenberg, Roger A; Discher, Dennis E

    2017-01-23

    Migration through micron-size constrictions has been seen to rupture the nucleus, release nuclear-localized GFP, and cause localized accumulations of ectopic 53BP1-a DNA repair protein. Here, constricted migration of two human cancer cell types and primary mesenchymal stem cells (MSCs) increases DNA breaks throughout the nucleoplasm as assessed by endogenous damage markers and by electrophoretic "comet" measurements. Migration also causes multiple DNA repair proteins to segregate away from DNA, with cytoplasmic mis-localization sustained for many hours as is relevant to delayed repair. Partial knockdown of repair factors that also regulate chromosome copy numbers is seen to increase DNA breaks in U2OS osteosarcoma cells without affecting migration and with nucleoplasmic patterns of damage similar to constricted migration. Such depletion also causes aberrant levels of DNA. Migration-induced nuclear damage is nonetheless reversible for wild-type and sub-cloned U2OS cells, except for lasting genomic differences between stable clones as revealed by DNA arrays and sequencing. Gains and losses of hundreds of megabases in many chromosomes are typical of the changes and heterogeneity in bone cancer. Phenotypic differences that arise from constricted migration of U2OS clones are further illustrated by a clone with a highly elongated and stable MSC-like shape that depends on microtubule assembly downstream of the transcription factor GATA4. Such changes are consistent with reversion to a more stem-like state upstream of cancerous osteoblastic cells. Migration-induced genomic instability can thus associate with heritable changes.

  20. Arachidonic acid randomizes endothelial cell motion and regulates adhesion and migration.

    PubMed

    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.

  1. 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.

  2. Cerium migration during PEM fuel cell accelerated stress testing

    DOE PAGES

    Baker, Andrew M.; Mukundan, Rangachary; Borup, Rodney L.; ...

    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

  3. The Autophagy Machinery: A New Player in Chemotactic Cell Migration

    PubMed Central

    Coly, Pierre-Michaël; Gandolfo, Pierrick; Castel, Hélène; Morin, Fabrice

    2017-01-01

    Autophagy is a highly conserved self-degradative process that plays a key role in diverse cellular processes such as stress response or differentiation. A growing body of work highlights the direct involvement of autophagy in cell migration and cancer metastasis. Specifically, autophagy has been shown to be involved in modulating cell adhesion dynamics as well as epithelial-to-mesenchymal transition. After providing a general overview of the mechanisms controlling autophagosome biogenesis and cell migration, we discuss how chemotactic G protein-coupled receptors, through the repression of autophagy, may orchestrate membrane trafficking and compartmentation of specific proteins at the cell front in order to support the critical steps of directional migration. PMID:28261054

  4. HMGCR positively regulated the growth and migration of glioblastoma cells.

    PubMed

    Qiu, Zhihua; Yuan, Wen; Chen, Tao; Zhou, Chenzhi; Liu, Chao; Huang, Yongkai; Han, Deqing; Huang, Qinghui

    2016-01-15

    The metabolic program of cancer cells is significant different from the normal cells, which makes it possible to develop novel strategies targeting cancer cells. Mevalonate pathway and its rate-limiting enzyme HMG-CoA reductase (HMGCR) have shown important roles in the progression of several cancer types. However, their roles in glioblastoma cells remain unknown. In this study, up-regulation of HMGCR in the clinical glioblastoma samples was observed. Forced expression of HMGCR promoted the growth and migration of U251 and U373 cells, while knocking down the expression of HMGCR inhibited the growth, migration and metastasis of glioblastoma cells. Molecular mechanism studies revealed that HMGCR positively regulated the expression of TAZ, an important mediator of Hippo pathway, and the downstream target gene connective tissue growth factor (CTGF), suggesting HMGCR might activate Hippo pathway in glioblastoma cells. Taken together, our study demonstrated the oncogenic roles of HMGCR in glioblastoma cells and HMGCR might be a promising therapeutic target.

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

    PubMed

    Tayalia, Prakriti; Mazur, Eric; Mooney, David J

    2011-04-01

    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.

  6. Building Responsive Health Systems to Help Communities Affected by Migration: An International Delphi Consensus

    PubMed Central

    Pottie, Kevin; Hui, Charles; Rahman, Prinon; Ingleby, David; Akl, Elie A.; Russell, Grant; Ling, Li; Wickramage, Kolitha; Mosca, Davide; Brindis, Claire D.

    2017-01-01

    Persons affected by migration require health systems that are responsive and adaptable to the needs of both disadvantaged migrants and non-migrant populations. The objective of this study is to support health systems for populations affected by migration. Materials and Methods: An international Delphi consensus process was used to identify policy approaches to improve health systems for populations affected by migration. Participants were leading migrant health experts from Americas, Europe, Middle East, Asia, and Australasia. We calculated average ranking scores and qualitatively analyzed open-ended questions. Results: Participants identified the following key areas as priorities for policy development: health inequities, system discrimination, migrant related health data, disadvantaged migrant sub-groups, and considerations for disadvantaged non-migrant populations. Highly ranked items to improve health systems were: Health Equity Impact Assessment, evidence based guidelines, and the International Organization for Migration annual reports. Discussion: Policy makers need tools, data and resources to address health systems challenges. Policies need to avoid preventable deaths of migrants and barriers to basic health services. PMID:28165380

  7. Metformin Inhibits Migration and Invasion of Cholangiocarcinoma Cells

    PubMed

    Trinh, Son Xuan; Nguyen, Huyen Thi Bich; Saimuang, Kween; Prachayasittikul, Virapong; Chan On, Waraporn

    2017-02-01

    Background: Metformin is an oral anti-diabetic agent that has been widely prescribed for treatment of type II diabetes. Anti-cancer properties of metformin have been revealed for numerous human malignancies including cholangiocarcinoma (CCA) with anti-proliferative effects in vitro. However, effects on CCA cell migration and invasion have not been fully investigated. The present study aimed to explore the inhibitory effects of metformin on motility, migration and invasion of the CCA cell line HuCCT1, and examine molecular mechanisms underlying metformin effects. Methods: HuCCT1 cells were exposed to increasing doses of metformin. Viability and growth of HuCCT1 cells were assessed by MTS and colony formation assays, respectively. Motility, migration and invasion of metformin-treated HuCCT1 cells were determined in vitro using wound healing, transwell migration and matrigel invasion assays. Expression of signaling molecules and epithelial-mesenchymal transition (EMT) markers was assessed by Western blotting. Results: It was observed that metformin significantly decreased HuCCT1 cell viability and colony formation. The agent also markedly reduced wound closure, migration and invasion of HuCCT1 cells. Furthermore, metformin exposure resulted in decreased STAT3 activation and down-regulation of anti-apoptotic protein Bcl-2 and Mcl-1 expression. In addition, it upregulated the expression of E-cadherin, while downregulating that of N-cadherin, Snail, and MMP-2. Conclusion: These results demonstrated inhibitory effects of metformin on CCA cell migration and invasion, possibly involving the STAT3 pathway and reversal of EMT markers expression. They further suggest that metformin may be useful for CCA management.

  8. Microtopography and flow modulate the direction of endothelial cell migration.

    PubMed

    Uttayarat, P; Chen, M; Li, M; Allen, F D; Composto, R J; Lelkes, P I

    2008-02-01

    The migration of vascular endothelial cells under flow can be modulated by the addition of chemical or mechanical stimuli. The aim of this study was to investigate how topographic cues derived from a substrate containing three-dimensional microtopography interact with fluid shear stress in directing endothelial cell migration. Subconfluent bovine aortic endothelial cells were seeded on fibronectin-coated poly(dimethylsiloxane) substrates patterned with a combinatorial array of parallel and orthogonal microgrooves ranging from 2 to 5 microm in width at a constant depth of 1 microm. During a 4-h time-lapse observation in the absence of flow, the majority of the prealigned cells migrated parallel to the grooves with the distribution of their focal adhesions (FAs) depending on the groove width. No change in this migratory pattern was observed after the cells were exposed to moderate shear stress (13.5 dyn/cm(2)), irrespective of groove direction with respect to flow. After 4-h exposure to high shear stress (58 dyn/cm(2)) parallel to the grooves, the cells continued to migrate in the direction of both grooves and flow. By contrast, when microgrooves were oriented perpendicular to flow, most cells migrated orthogonal to the grooves and downstream with flow. Despite the change in the migration direction of the cells under high shear stress, most FAs and actin microfilaments maintained their original alignment parallel to the grooves, suggesting that topographic cues were more effective than those derived from shear stress in guiding the orientation of cytoskeletal and adhesion proteins during the initial exposure to flow.

  9. Quantitative 3D analysis of complex single border cell behaviors in coordinated collective cell migration.

    PubMed

    Cliffe, Adam; Doupé, David P; Sung, HsinHo; Lim, Isaac Kok Hwee; Ong, Kok Haur; Cheng, Li; Yu, Weimiao

    2017-04-04

    Understanding the mechanisms of collective cell migration is crucial for cancer metastasis, wound healing and many developmental processes. Imaging a migrating cluster in vivo is feasible, but the quantification of individual cell behaviours remains challenging. We have developed an image analysis toolkit, CCMToolKit, to quantify the Drosophila border cell system. In addition to chaotic motion, previous studies reported that the migrating cells are able to migrate in a highly coordinated pattern. We quantify the rotating and running migration modes in 3D while also observing a range of intermediate behaviours. Running mode is driven by cluster external protrusions. Rotating mode is associated with cluster internal cell extensions that could not be easily characterized. Although the cluster moves slower while rotating, individual cells retain their mobility and are in fact slightly more active than in running mode. We also show that individual cells may exchange positions during migration.

  10. Paxillin-kinase-linker tyrosine phosphorylation regulates directional cell migration.

    PubMed

    Yu, Jianxin A; Deakin, Nicholas O; Turner, Christopher E

    2009-11-01

    Directed cell migration requires the coordination of growth factor and cell adhesion signaling and is of fundamental importance during embryonic development, wound repair, and pathological conditions such as tumor metastasis. Herein, we demonstrate that the ArfGAP, paxillin-kinase-linker (PKL/GIT2), is tyrosine phosphorylated in response to platelet-derived growth factor (PDGF) stimulation, in an adhesion dependent manner and is necessary for directed cell migration. Using a combination of pharmacological inhibitors, knockout cells and kinase mutants, FAK, and Src family kinases were shown to mediate PDGF-dependent PKL tyrosine phosphorylation. In fibroblasts, expression of a PKL mutant lacking the principal tyrosine phosphorylation sites resulted in loss of wound-induced cell polarization as well as directional migration. PKL phosphorylation was necessary for PDGF-stimulated PKL binding to the focal adhesion protein paxillin and expression of paxillin or PKL mutants defective in their respective binding motifs recapitulated the polarization defects. RNA interference or expression of phosphorylation mutants of PKL resulted in disregulation of PDGF-stimulated Rac1 and PAK activities, reduction of Cdc42 and Erk signaling, as well as mislocalization of betaPIX. Together these studies position PKL as an integral component of growth factor and cell adhesion cross-talk signaling, controlling the development of front-rear cell polarity and directional cell migration.

  11. The planar polarity pathway promotes coordinated cell migration during Drosophila oogenesis

    PubMed Central

    Bastock, Rebecca; Strutt, David

    2007-01-01

    SUMMARY Cell migration is fundamental in both animal morphogenesis and disease. The migration of individual cells is relatively well-studied, however in vivo cells often remain joined by cell-cell junctions and migrate in cohesive groups. How such groups of cells coordinate their migration is poorly understood. The planar polarity pathway coordinates the polarity of non-migrating cells in epithelial sheets and is required for cell rearrangements during vertebrate morphogenesis. It is therefore a good candidate to play a role in collective migration of groups of cells. Drosophila border cell migration is a well-characterised and genetically tractable model of collective cell migration, during which a group of about 6-10 epithelial cells detaches from the anterior end of the developing egg chamber and migrates invasively towards the oocyte. We find that the planar polarity pathway promotes this invasive migration, acting both in the migrating cells themselves and in the non-migratory polar follicle cells they carry along. Disruption of planar polarity signalling causes abnormalities in actin rich processes on the cell surface and leads to less efficient migration. This is apparently due in part to loss of regulation of Rho GTPase activity by the planar polarity receptor Frizzled, which itself becomes localised to the migratory edge of the border cells. We conclude that during collective cell migration the planar polarity pathway can mediate communication between motile and non-motile cells, which enhances the efficiency of migration via the modulation of actin dynamics. PMID:17652348

  12. 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

  13. 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.

  14. 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.

  15. Fibrin glue inhibits migration of ocular surface epithelial cells.

    PubMed

    Yeung, A M; Faraj, L A; McIntosh, O D; Dhillon, V K; Dua, H S

    2016-10-01

    PurposeFibrin glue has been used successfully in numerous ophthalmic surgical procedures. Recently, fibrin glue has been used in limbal stem cell transplantation to reduce both operative time and to negate the need for sutures. The aim of this study was to determine the effects of fibrin glue on epithelial cell migration in vitro.MethodsCorneoscleral rims were split to retain the epithelial layer, Bowman's layer, and anterior stroma. Rims were cut into eight equal-sized pieces and were placed directly on culture plates or affixed with fibrin glue. Rims were maintained in culture for 25 days and epithelial cell growth was monitored. Cells were photographed to measure area or growth and immunofluorescence staining of explants for fibrin was performed.ResultsExplants that were glued demonstrated significantly delayed epithelial cell growth and migration as compared with explants without glue. By day 16, all fibrin glue had dissolved and coincided with onset of cell growth from glued explants. Cell growth commenced between days 3 and 4 for control explants without glue and around days 14-16 for explants with fibrin glue.ConclusionsFibrin glue delays epithelial cell migration by acting as a physical barrier and can potentially interfere with explant-derived limbal epithelial cell migration on to the corneal surface. We propose that glue should be used to attach the conjunctival frill of the limbal explant but care should be taken to ensure that the glue does not wrap around the explant if used to secure the explant as well. Strategic use of glue, to attach the recessed conjunctiva, can be advantageous in delaying conjunctival cell migration and reducing the need for sequential sector conjunctival epitheliectomy.

  16. 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.

  17. 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

  18. 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

  19. 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.

  20. 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

  1. Osteopontin improves adhesion and migration of human primary renal cortical epithelial cells during wound healing

    PubMed Central

    Wu, Jinfeng; Wang, Zuolin

    2016-01-01

    The aim of the present study was to investigate the effect of osteopontin (OPN) on adhesion and migration in human primary renal cortical epithelial cells during wound healing and Transwell assays. MTT assay was used to examine the cell viability and western blot analysis was used to examine the expression of cytoskeletal proteins and cell adhesion molecules. The results showed that overexpression of OPN had positive effects on the viability, proliferation, adhesion and migration of the human primary renal cortical epithelial cells. In addition, the integrity of the cell membrane and cytoskeleton of the epithelial cells was negatively affected by knockdown of OPN expression. The Transwell migration and a wound healing assays performed using OPN-knockdown cells suggested that OPN had a significant impact on cell migration (P=0.0421) and wound healing (P=0.0333). Therefore, OPN may be a potential target for the therapeutic modulation of skin repair to improve the healing rate and quality of wound healing. PMID:28101213

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

    PubMed

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

    2016-07-07

    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.

  3. 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.

  4. 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.

  5. 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.

  6. Adhesion and migration of cells responding to microtopography.

    PubMed

    Estévez, Maruxa; Martínez, Elena; Yarwood, Stephen J; Dalby, Matthew J; Samitier, Josep

    2015-05-01

    It is known that cells respond strongly to microtopography. However, cellular mechanisms of response are unclear. Here, we study wild-type fibroblasts responding to 25 µm(2) posts and compare their response to that of FAK(-/-) fibroblasts and fibroblasts with PMA treatment to stimulate protein kinase C (PKC) and the small g-protein Rac. FAK knockout cells modulated adhesion number and size in a similar way to cells on topography; that is, they used more, smaller adhesions, but migration was almost completely stalled demonstrating the importance of FAK signaling in contact guidance and adhesion turnover. Little similarity, however, was observed to PKC stimulated cells and cells on the topography. Interestingly, with PKC stimulation the cell nuclei became highly deformable bringing focus on these surfaces to the study of metastasis. Surfaces that aid the study of cellular migration are important in developing understanding of mechanisms of wound healing and repair in aligned tissues such as ligament and tendon.

  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. Dynamic Quantification of Host Schwann Cell Migration into Peripheral Nerve Allografts

    PubMed Central

    Whitlock, Elizabeth L.; Myckatyn, Terence M.; Tong, Alice Y.; Yee, Andrew; Yan, Ying; Magill, Christina K.; Johnson, Philip J.; Mackinnon, Susan E.

    2010-01-01

    Host Schwann cell (SC) migration into nerve allografts is the limiting factor in the duration of immunosuppression following peripheral nerve allotransplantation, and may be affected by different immunosuppressive regimens. Our objective was to compare SC migration patterns between clinical and experimental immunosuppression regimens both over time and at the harvest endpoint. Eighty mice that express GFP under the control of the Schwann cell specific S100 promoter were engrafted with allogeneic, nonfluorescent sciatic nerve grafts. Mice received immunosuppression with either tacrolimus (FK506), or experimental T-cell triple costimulation blockade (CSB), consisting of CTLA4-immunoglobulin fusion protein, anti-CD40 monoclonal antibody, and anti-inducible costimulator monoclonal antibody. Migration of GFP-expressing host SCs into wild-type allografts was assessed in vivo every 3 weeks until 15 weeks postoperatively, and explanted allografts were evaluated for immunohistochemical staining patterns to differentiate graft from host SCs. Immunosuppression with tacrolimus exhibited a plateau of SC migration, characterized by significant early migration (< 3 weeks) followed by a constant level of host SCs in the graft (15 weeks). At the endpoint, graft fluorescence was decreased relative to surrounding host nerve, and donor SCs persisted within the graft. CSB-treated mice displayed gradually increasing migration of host SCs into the graft, without the plateau noted in tacrolimus-treated mice, and also maintained a population of donor SCs at the 15-week endpoint. SC migration patterns are affected by immunosuppressant choice, particularly in the immediate postoperative period, and the use of a single treatment of CSB may allow for gradual population of nerve allografts with host SCs. PMID:20633557

  9. 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.

  10. Real-Time Video-Microscopy of Migrating Immune Cells in Altered Gravity During Parabolic Flights

    NASA Astrophysics Data System (ADS)

    Lang, Kerstin; Strell, Carina; Niggemann, Bernd; Zänker, Kurt S.; Hilliger, Andre; Engelmann, Frank; Ullrich, Oliver

    2010-02-01

    In our project we developed a technical equipment which allows to visualize migration of cells in real-time video-microscopy during altered gravity conditions of NOVESPACE Airbus A300 ZERO-G parabolic flights. For validation of the experimental device we have used fast moving human neutrophils as example, because their migration is fundamental to keep the organism under immunological surveillance. Their migration is indispensable for immune effector function, where the cells leave the blood vessels and navigate to places of infection to fulfill their main task of phagocytosis. Thereby, we have analyzed if their migration is affected during altered gravity conditions and if pharmacological modification of cytoskeletal dynamics influences neutrophil migratory activity. Whereas we detected no change in neutrophil locomotory behaviour in microgravity, we found a significant inhibitory influence of hypergravity, irrespective of the chemical stimulus used. Our results suggest that hypergravity, following a microgravity environment, could represent a hazard to the human immune system function. Thus, our cell migration assay offers an optimum experimental device for studying the migratory activity and underlying signal transduction mechanisms of neutrophils to assess the immunological fitness of humans in space to fight infection, but also for investigating the locomotion of other cell types or unicellular organisms such as ciliates.

  11. Lesion-induced increase in survival and migration of human neural progenitor cells releasing GDNF

    PubMed Central

    Behrstock, Soshana; Ebert, Allison D.; Klein, Sandra; Schmitt, Melanie; Moore, Jeannette M.; Svendsen, Clive N.

    2009-01-01

    The use of human neural progenitor cells (hNPC) has been proposed to provide neuronal replacement or astrocytes delivering growth factors for brain disorders such as Parkinson’s and Huntington’s disease. Success in such studies likely requires migration from the site of transplantation and integration into host tissue in the face of ongoing damage. In the current study, hNPC modified to release glial cell line derived neurotrophic factor (hNPCGDNF) were transplanted into either intact or lesioned animals. GDNF release itself had no effect on the survival, migration or differentiation of the cells. The most robust migration and survival was found using a direct lesion of striatum (Huntington’s model) with indirect lesions of the dopamine system (Parkinson’s model) or intact animals showing successively less migration and survival. No lesion affected differentiation patterns. We conclude that the type of brain injury dictates migration and integration of hNPC which has important consequences when considering transplantation of these cells as a therapy for neurodegenerative diseases. PMID:19044202

  12. Intravital characterization of tumor cell migration in pancreatic cancer

    PubMed Central

    Beerling, Evelyne; Oosterom, Ilse; Voest, Emile; Lolkema, Martijn; van Rheenen, Jacco

    2016-01-01

    ABSTRACT Curing pancreatic cancer is difficult as metastases often determine the poor clinical outcome. To gain more insight into the metastatic behavior of pancreatic cancer cells, we characterized migratory cells in primary pancreatic tumors using intravital microscopy. We visualized the migratory behavior of primary tumor cells of a genetically engineered pancreatic cancer mouse model and found that pancreatic tumor cells migrate with a mesenchymal morphology as single individual cells or collectively as a stream of non-cohesive single motile cells. These findings may improve our ability to conceive treatments that block metastatic behavior. PMID:28243522

  13. 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.

  14. 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

  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. 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.

  17. 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

  18. Schwann cell migration and neurite outgrowth are influenced by media conditioned by epineurial fibroblasts.

    PubMed

    van Neerven, S G A; Pannaye, P; Bozkurt, A; Van Nieuwenhoven, F; Joosten, E; Hermans, E; Taccola, G; Deumens, R

    2013-11-12

    The regenerative capacity of the peripheral nervous system is largely related to Schwann cells undergoing proliferation and migration after injury and forming growth-supporting substrates for severed axons. Novel data show that fibroblasts to a certain extent regulate the pro-regenerative behavior of Schwann cells. In the setting of peripheral nerve injury, the fibroblasts that form the epineurium come into close contact with both Schwann cells and peripheral axons, but the potential influence on these latter two cell types has not been studied yet. In the present study we explored whether culture media, conditioned by epineurial fibroblasts can influence Schwann cells and/or neurite outgrowth from dorsal root ganglia neurons in vitro. Our data indicate that epineurial fibroblast-conditioned culture media substantially increase Schwann cell migration and the outgrowth of neurites. Schwann cell proliferation remained largely unaffected. These same read-out parameters were assayed in a condition where epineurial fibroblasts were subjected to stretch-cell-stress, a mechanical stressor that plays an important role in traumatic peripheral nerve injuries. Stretch-cell-stress of epineurial fibroblasts did not further change the positive effects of conditioned media on Schwann cell migration and neurite outgrowth. From these data we conclude that an as yet unknown pro-regenerative role can be attributed to epineurial fibroblasts, implying that such cells may affect the outcome of severe peripheral nerve injury.

  19. Surface topography during neural stem cell differentiation regulates cell migration and cell morphology.

    PubMed

    Czeisler, Catherine; Short, Aaron; Nelson, Tyler; Gygli, Patrick; Ortiz, Cristina; Catacutan, Fay Patsy; Stocker, Ben; Cronin, James; Lannutti, John; Winter, Jessica; Otero, José Javier

    2016-12-01

    We sought to determine the contribution of scaffold topography to the migration and morphology of neural stem cells by mimicking anatomical features of scaffolds found in vivo. We mimicked two types of central nervous system scaffolds encountered by neural stem cells during development in vitro by constructing different diameter electrospun polycaprolactone (PCL) fiber mats, a substrate that we have shown to be topographically similar to brain scaffolds. We compared the effects of large fibers (made to mimic blood vessel topography) with those of small-diameter fibers (made to mimic radial glial process topography) on the migration and differentiation of neural stem cells. Neural stem cells showed differential migratory and morphological reactions with laminin in different topographical contexts. We demonstrate, for the first time, that neural stem cell biological responses to laminin are dependent on topographical context. Large-fiber topography without laminin prevented cell migration, which was partially reversed by treatment with rock inhibitor. Cell morphology complexity assayed by fractal dimension was inhibited in nocodazole- and cytochalasin-D-treated neural precursor cells in large-fiber topography, but was not changed in small-fiber topography with these inhibitors. These data indicate that cell morphology has different requirements on cytoskeletal proteins dependent on the topographical environment encountered by the cell. We propose that the physical structure of distinct scaffolds induces unique signaling cascades that regulate migration and morphology in embryonic neural precursor cells. J. Comp. Neurol. 524:3485-3502, 2016. © 2016 Wiley Periodicals, Inc.

  20. The effect of Kisspeptin-10 on mesenchymal stem cells migration in vitro and in vivo

    PubMed Central

    Golzar, Fatemeh; Javanmard, Shaghayegh Haghjooy; Bahrambeigi, Vahid; Rafiee, Laleh

    2015-01-01

    Background: Kisspeptins (kp) activate a receptor coupled to a Gαq subunit (GPR54 or KiSS-1R) receptor to perform a variety of functions, including inhibition of cell motility, chemotaxis, and metastasis. In this study we have investigated whether kp-10, the most potent member of the kisspeptin family, can modulate CXCR4 (C-X-C chemokine receptor type 4) expression and mesenchymal stem cells (MSCs) migration that may influence the development of tumors. Materials and Methods: We compared the directional migration of MSCs treated with 10-100 or 500 nM kp-10 for 24 hours and no treated cells using an in vitro transmembrane migration assay. In addition, Chloromethylbenzamido Dialkylacarbocyanine (CM-Dil) labeled adipose-derived mesenchymal stem cells treated with 10-100 or 500 nM kp-10 and no treated cells were transfused via the tail vein to the melanoma tumor bearing C57BL/6 mice. After 24 hours, the mice were scarified, the tumors were dissected, and the tumor cell suspensions were analyzed by flow cytometry for detection of CM-Dil+ MSCs. Results: We have found that kp-10 increased the MSCs migration at 100 nM, while it decreased the MSCs migration at 500 nM, both in vitro and in vivo, with a significant increase of CXCR4 expression at 100 nM kp-10 compared to the no treated cells, but it had no significant difference between the various concentrations of kp-10. Conclusion: Thus, our data showed that kp-10 can differently affect MSCs migration in various concentrations, probably through different effects on CXCR4 expression in various concentrations. PMID:25709985

  1. Exit Strategies: S1P Signaling and T Cell Migration.

    PubMed

    Baeyens, Audrey; Fang, Victoria; Chen, Cynthia; Schwab, Susan R

    2015-12-01

    Whereas the role of sphingosine 1-phosphate receptor 1 (S1PR1) in T cell egress and the regulation of S1P gradients between lymphoid organs and circulatory fluids in homeostasis are increasingly well understood, much remains to be learned about S1P signaling and distribution during an immune response. Recent data suggest that the role of S1PR1 in directing cells from tissues into circulatory fluids is reprised again and again, particularly in guiding activated T cells from non-lymphoid tissues into lymphatics. Conversely, S1P receptor 2 (S1PR2), which antagonizes migration towards chemokines, confines cells within tissues. Here we review the current understanding of the roles of S1P signaling in activated T cell migration. In this context, we outline open questions, particularly regarding the shape of S1P gradients in different tissues in homeostasis and inflammation, and discuss recent strategies to measure S1P.

  2. The MRL proteins: adapting cell adhesion, migration and growth.

    PubMed

    Coló, Georgina P; Lafuente, Esther M; Teixidó, Joaquin

    2012-01-01

    MIG-10, RIAM and Lamellipodin (Lpd) are the founding members of the MRL family of multi-adaptor molecules. These proteins have common domain structures but display distinct functions in cell migration and adhesion, signaling, and in cell growth. The binding of RIAM with active Rap1 and with talin provides these MRL molecules with important regulatory roles on integrin-mediated cell adhesion and migration. Furthermore, RIAM and Lpd can regulate actin dynamics through their binding to actin regulatory Ena/VASP proteins. Recent data generated with the Drosophila MRL ortholog called Pico and with RIAM in melanoma cells indicate that these proteins can also regulate cell growth. As MRL proteins represent a relatively new family, many questions on their structure-function relationships remain unanswered, including regulation of their expression, post-translational modifications, new interactions, involvement in signaling and their knockout mice phenotype.

  3. 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.

  4. Resveratrol inhibits IL-6-induced ovarian cancer cell migration through epigenetic up-regulation of autophagy.

    PubMed

    Ferraresi, Alessandra; Phadngam, Suratchanee; Morani, Federica; Galetto, Alessandra; Alabiso, Oscar; Chiorino, Giovanna; Isidoro, Ciro

    2017-03-01

    Interleukin-6 (IL-6), a pro-inflammatory cytokine released by cancer-associated fibroblasts, has been linked to the invasive and metastatic behavior of ovarian cancer cells. Resveratrol is a naturally occurring polyphenol with the potential to inhibit cancer cell migration. Here we show that Resveratrol and IL-6 affect in an opposite manner the expression of RNA messengers and of microRNAs involved in cell locomotion and extracellular matrix remodeling associated with the invasive properties of ovarian cancer cells. Among the several potential candidates responsible for the anti-invasive effect promoted by Resveratrol, here we focused our attention on ARH-I (DIRAS3), that encodes a Ras homolog GTPase of 26-kDa. This protein is known to inhibit cell motility, and it has been shown to regulate autophagy by interacting with BECLIN 1. IL-6 down-regulated the expression of ARH-I and inhibited the formation of LC3-positive autophagic vacuoles, while promoting cell migration. On opposite, Resveratrol could counteract the IL-6 induction of cell migration in ovarian cancer cells through induction of autophagy in the cells at the migration front, which was paralleled by up-regulation of ARH-I and down-regulation of STAT3 expression. Spautin 1-mediated disruption of BECLIN 1-dependent autophagy abrogated the effects of Resveratrol, while promoting cell migration. The present data indicate that Resveratrol elicits its anti-tumor effect through epigenetic mechanisms and support its inclusion in the chemotherapy regimen for highly aggressive ovarian cancers. © 2016 Wiley Periodicals, Inc.

  5. Plectin deficiency in liver cancer cells promotes cell migration and sensitivity to sorafenib treatment.

    PubMed

    Cheng, Chiung-Chi; Chao, Wei-Ting; Liao, Chen-Chun; Tseng, Yu-Hui; Lai, Yen-Chang Clark; Lai, Yih-Shyong; Hsu, Yung-Hsiang; Liu, Yi-Hsiang

    2017-02-17

    Plectin involved in activation of kinases in cell signaling pathway and plays important role in cell morphology and migration. Plectin knockdown promotes cell migration by activating focal adhesion kinase and Rac1-GTPase activity in liver cells. Sorafenib is a multi-targeting tyrosine kinase inhibitor that improves patient survival on hepatocellular carcinoma. The aim of this study is to investigate the correlation between the expression of plectin and cell migration as well as the sensitivity of hepatoma cell lines exposing to sorafenib. Hepatoma cell lines PLC/PRF/5 and HepG2 were used to examine the level of plectin expression and cell migration in comparison with Chang liver cell line. In addition, sensitivity of the 3 cell lines to sorafenib treatment was also measured. Expression of plectin was lower in PLC/PRF/5 and HepG2 hepatoma cells than that of Chang liver cells whereas HepG2 and PLC/PRF/5 cells exhibit higher rate of cell migration in trans-well migration assay. Immunohistofluorecent staining on E-cadherin revealed the highest rate of collective cell migration in HepG2 cells and the lowest was found in Chang liver cells. Likewise, HepG2 cell line was most sensitive to sorafenib treatment and Chang liver cells exhibited the least sensitivity. The drug sensitivity to sorafenib treatment showed inverse correlation with the expression of plectin. We suggest that plectin deficiency and increased E-cadherin in hepatoma cells were associated with higher rates of cell motility, collective cell migration as well as higher drug sensitivity to sorafenib treatment.

  6. Guidance signalling regulates leading edge behaviour during collective cell migration of cardiac cells in Drosophila.

    PubMed

    Raza, Qanber; Jacobs, J Roger

    2016-11-15

    Collective cell migration is the coordinated movement of cells, which organize tissues during morphogenesis, repair and some cancers. The motile cell membrane of the advancing front in collective cell migration is termed the Leading Edge. The embryonic development of the vertebrate and Drosophila hearts are both characterized by the coordinated medial migration of a bilateral cluster of mesodermal cells. In Drosophila, the cardioblasts form cohesive bilateral rows that migrate collectively as a unit towards the dorsal midline to form the dorsal vessel. We have characterized the collective cell migration of cardioblasts as an in vivo quantitative model to study the behaviour of the Leading Edge. We investigated whether guidance signalling through Slit and Netrin pathways plays a role in cell migration during heart development. Through time-lapse imaging and quantitative assessment of migratory behaviour of the cardioblasts in loss-of-function mutants, we demonstrate that both Slit and Netrin mediated signals are autonomously and concomitantly required to maximize migration velocity, filopodial and lamellipodial activities. Additionally, we show that another Slit and Netrin receptor, Dscam1, the role of which during heart development was previously unknown, is required for both normal migration of cardioblasts and luminal expansion. Leading edge behaviour analysis revealed a dosage dependent genetic interaction between Slit and Netrin receptors suggesting that downstream signalling through these receptors converge on a common output that increases leading edge activity of the cardioblasts. Finally, we found that guidance signalling maintains the balance between epithelial and mesenchymal characteristics of the migrating cardioblasts.

  7. Involvement of the cellular prion protein in the migration of brain microvascular endothelial cells.

    PubMed

    Watanabe, Takuya; Yasutaka, Yuki; Nishioku, Tsuyoshi; Kusakabe, Sae; Futagami, Koujiro; Yamauchi, Atsushi; Kataoka, Yasufumi

    2011-06-01

    The conversion of cellular prion protein (PrP(C)) to its protease-resistant isoform is involved in the pathogenesis of prion disease. Although PrP(C) is a ubiquitous glycoprotein that is present in various cell types, the physiological role of PrP(C) remains obscure. The present study aimed to determine whether PrP(C) mediates migration of brain microvascular endothelial cells. Small interfering RNAs (siRNAs) targeting PrP(C) were transfected into a mouse brain microvascular endothelial cell line (bEND.3 cells). siPrP1, selected among three siRNAs, reduced mRNA and protein levels of PrP(C) in bEND.3 cells. Cellular migration was evaluated with a scratch-wound assay. siPrP1 suppressed migration without significantly affecting cellular proliferation. This study provides the first evidence that PrP(C) may be necessary for brain microvascular endothelial cells to migrate into damaged regions in the brain. This function of PrP(C) in the brain endothelium may be a mechanism by which the neurovascular unit recovers from an injury such as an ischemic insult.

  8. 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

  9. Topographical guidance of 3D tumor cell migration at an interface of collagen densities.

    PubMed

    Bordeleau, Francois; Tang, Lauren N; Reinhart-King, Cynthia A

    2013-12-01

    During cancer progression, metastatic cells leave the primary tumor and invade into the fibrous extracellular matrix (ECM) within the surrounding stroma. This ECM network is highly heterogeneous, and interest in understanding how this network can affect cell behavior has increased in the past several decades. However, replicating this heterogeneity has proven challenging. Here, we designed and utilized a method to create a well-defined interface between two distinct regions of high- and low-density collagen gels to mimic the heterogeneities in density found in the tumor stroma. We show that cells will invade preferentially from the high-density side into the low-density side. We also demonstrate that the net cell migration is a function of the density of the collagen in which the cells are embedded, and the difference in density between the two regions has minimal effect on cell net displacement and distance travelled. Our data further indicate that a low-to-high density interface promotes directional migration and induces formation of focal adhesion on the interface surface. Together, the current results demonstrate how ECM heterogeneities, in the form of interfacial boundaries, can affect cell migration.

  10. 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.

  11. Cell-Substrate Interactions Feedback to Direct Cell Migration along or against Morphological Polarization

    PubMed Central

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

    2015-01-01

    In response to external stimuli, cells polarize morphologically into teardrop shapes prior to moving in the direction of their blunt leading edge through lamellipodia extension and retraction of the rear tip. This textbook description of cell migration implies that the initial polarization sets the direction of cell migration. Using microfabrication techniques to control cell morphologies and the direction of migration without gradients, we demonstrate that after polarization, lamelipodia extension and attachment can feedback to change and even reverse the initial morphological polarization. Cells do indeed migrate faster in the direction of their morphologically polarization. However, feedback from subsequent lamellipodia extension and attachment can be so powerful as to induce cells to reverse and migrate against their initial polarization, albeit at a slower speed. Constitutively active mutants of RhoA show that RhoA stimulates cell motility when cells are guided either along or against their initial polarization. Cdc42 activation and inhibition, which results in loss of directional motility during chemotaxis, only reduces the speed of migration without altering the directionality of migration on the micropatterns. These results reveal significant differences between substrate directed cell migration and that induced by chemotactic gradients. PMID:26186588

  12. Endogenous electric fields as guiding cue for cell migration.

    PubMed

    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.

  13. Monocyte-expressed urokinase regulates human vascular smooth muscle cell migration in a coculture model.

    PubMed

    Kusch, Angelika; Tkachuk, Sergey; Lutter, Steffen; Haller, Hermann; Dietz, Rainer; Lipp, Martin; Dumler, Inna

    2002-01-01

    Interactions of vascular smooth muscle cells (VSMC) with monocytes recruited to the arterial wall at a site of injury, with resultant modulation of VSMC growth and migration, are central to the development of vascular intimal thickening. Urokinase-type plasminogen activator (uPA) expressed by monocytes is a potent chemotactic factor for VSMC and might serve for the acceleration of vascular remodeling. In this report, we demonstrate that coculture of human VSMC with freshly isolated peripheral blood-derived human monocytes results in significant VSMC migration that increases during the coculture period. Accordingly, VSMC adhesion was inhibited with similar kinetics. VSMC proliferation, however, was not affected and remained at the same basal level during the whole period of coculture. The increase of VSMC migration in coculture was equivalent to the uPA-induced migration of monocultured VSMC and was blocked by addition into coculture of soluble uPAR (suPAR). Analysis of uPA and uPAR expression in cocultured cells demonstrated that monocytes are a major source of uPA, whose expression increases in coculture five-fold, whereas VSMC display an increased expression of cell surface-associated uPAR. These findings indicate that upregulated uPA production by monocytes following vascular injury acts most likely as an endogenous activator of VSMC migration contributing to the remodeling of vessel walls.

  14. Annexin A1 Induces Skeletal Muscle Cell Migration Acting through Formyl Peptide Receptors

    PubMed Central

    Bizzarro, Valentina; Belvedere, Raffaella; Dal Piaz, Fabrizio; Parente, Luca; Petrella, Antonello

    2012-01-01

    Annexin A1 (ANXA1, lipocortin-1) is a glucocorticoid-regulated 37-kDa protein, so called since its main property is to bind (i.e. to annex) to cellular membranes in a Ca2+-dependent manner. Although ANXA1 has predominantly been studied in the context of immune responses and cancer, the protein can affect a larger variety of biological phenomena, including cell proliferation and migration. Our previous results show that endogenous ANXA1 positively modulates myoblast cell differentiation by promoting migration of satellite cells and, consequently, skeletal muscle differentiation. In this work, we have evaluated the hypothesis that ANXA1 is able to exert effects on myoblast cell migration acting through formyl peptide receptors (FPRs) following changes in its subcellular localization as in other cell types and tissues. The analysis of the subcellular localization of ANXA1 in C2C12 myoblasts during myogenic differentiation showed an interesting increase of extracellular ANXA1 starting from the initial phases of skeletal muscle cell differentiation. The investigation of intracellular Ca2+ perturbation following exogenous administration of the ANXA1 N-terminal derived peptide Ac2-26 established the engagement of the FPRs which expression in C2C12 cells was assessed by qualitative PCR. Wound healing assay experiments showed that Ac2-26 peptide is able to increase migration of C2C12 skeletal muscle cells and to induce cell surface translocation and secretion of ANXA1. Our results suggest a role for ANXA1 as a highly versatile component in the signaling chains triggered by the proper calcium perturbation that takes place during active migration and differentiation or membrane repair since the protein is strongly redistributed onto the plasma membranes after an rapid increase of intracellular levels of Ca2+. These properties indicate that ANXA1 may be involved in a novel repair mechanism for skeletal muscle and may have therapeutic implications with respect to the

  15. Mapping forces and kinematics during collective cell migration.

    PubMed

    Serra-Picamal, Xavier; Conte, Vito; Sunyer, Raimon; Muñoz, José J; Trepat, Xavier

    2015-01-01

    Fundamental biological processes including morphogenesis and tissue repair require cells to migrate collectively. In these processes, epithelial or endothelial cells move in a cooperative manner coupled by intercellular junctions. Ultimately, the movement of these multicellular systems occurs through the generation of cellular forces, exerted either on the substrate via focal adhesions (cell-substrate forces) or on neighboring cells through cell-cell junctions (cell-cell forces). Quantitative measurements of multicellular forces and kinematics with cellular or subcellular resolution have become possible only in recent years. In this chapter, we describe some of these techniques, which include particle image velocimetry to map cell velocities, traction force microscopy to map forces exerted by cells on the substrate, and monolayer stress microscopy to map forces within and between cells. We also describe experimental protocols to perform these measurements. The combination of these techniques with high-resolution imaging tools and molecular perturbations will lead to a better understanding of the mechanisms underlying collective cell migration in health and disease.

  16. Urokinase type plasminogen activator mediates Interleukin-17-induced peripheral blood mesenchymal stem cell motility and transendothelial migration.

    PubMed

    Krstić, Jelena; Obradović, Hristina; Jauković, Aleksandra; Okić-Đorđević, Ivana; Trivanović, Drenka; Kukolj, Tamara; Mojsilović, Slavko; Ilić, Vesna; Santibañez, Juan F; Bugarski, Diana

    2015-02-01

    Mesenchymal stem cells (MSCs) have the potential to migrate toward damaged tissues increasing tissue regeneration. Interleukin-17 (IL-17) is a proinflammatory cytokine with pleiotropic effects associated with many inflammatory diseases. Although IL-17 can modulate MSC functions, its capacity to regulate MSC migration is not well elucidated so far. Here, we studied the role of IL-17 on peripheral blood (PB) derived MSC migration and transmigration across endothelial cells. IL-17 increased PB-MSC migration in a wound healing assay as well as cell mobilization from collagen gel. Concomitantly IL-17 induced the expression of urokinase type plasminogen activator (uPA) without affecting matrix metalloproteinase expression. The incremented uPA expression mediated the capacity of IL-17 to enhance PB-MSC migration in a ERK1,2 MAPK dependent way. Also, IL-17 induced PB-MSC migration alongside with changes in cell polarization and uPA localization in cell protrusions. Moreover, IL-17 increased PB-MSC adhesion to endothelial cells and transendothelial migration, as well as increased the capacity of PB-MSC adhesion to fibronectin, in an uPA-dependent fashion. Therefore, our data suggested that IL-17 may act as chemotropic factor for PB-MSCs by incrementing cell motility and uPA expression during inflammation development.

  17. Regulation of Cell Migration in Breast Cancer

    DTIC Science & Technology

    2011-04-01

    fluorescence using TRlTC-phalloidin, caveolin and integrin antibodies. Nuclei were counterstained with DAPL Task 2.Determine the effect of Rsu-1 and the IPP...phalloidin. Cells were also costained with TRITC phalloidin and viinculin antibodies. Nuclei were counterstained with DAPl . 5 Task 3. Determine the

  18. Senescent fibroblast-derived Chemerin promotes squamous cell carcinoma migration

    PubMed Central

    Gatzka, Martina; Treiber, Nicolai; Schneider, Lars A.; Mulaw, Medhanie A.; Lucas, Tanja; Kochanek, Stefan; Dummer, Reinhard; Levesque, Mitchell P.; Wlaschek, Meinhard; Scharffetter-Kochanek, Karin

    2016-01-01

    Aging is associated with a rising incidence of cutaneous squamous cell carcinoma (cSCC), an aggressive skin cancer with the potential for local invasion and metastasis. Acquisition of a senescence-associated secretory phenotype (SASP) in dermal fibroblasts has been postulated to promote skin cancer progression in elderly individuals. The underlying molecular mechanisms are largely unexplored. We show that Chemerin, a previously unreported SASP factor released from senescent human dermal fibroblasts, promotes cSCC cell migration, a key feature driving tumor progression. Whereas the Chemerin abundance is downregulated in malignant cSCC cells, increased Chemerin transcripts and protein concentrations are detected in replicative senescent fibroblasts in vitro and in the fibroblast of skin sections from old donors, indicating that a Chemerin gradient is built up in the dermis of elderly. Using Transwell® migration assays, we show that Chemerin enhances the chemotaxis of different cSCC cell lines. Notably, the Chemerin receptor CCRL2 is remarkably upregulated in cSCC cell lines and human patient biopsies. Silencing Chemerin in senescent fibroblasts or the CCRL2 and GPR1 receptors in the SCL-1 cSCC cell line abrogates the Chemerin-mediated chemotaxis. Chemerin triggers the MAPK cascade via JNK and ERK1 activation, whereby the inhibition impairs the SASP- or Chemerin-mediated cSCC cell migration. Taken together, we uncover a key role for Chemerin, as a major factor in the secretome of senescent fibroblasts, promoting cSCC cell migration and possibly progression, relaying its signals through CCRL2 and GPR1 receptors with subsequent MAPK activation. These findings might have implications for targeted therapeutic interventions in elderly patients. PMID:27907906

  19. Leukocyte-specific protein 1 regulates T-cell migration in rheumatoid arthritis.

    PubMed

    Hwang, Seong-Hye; Jung, Seung-Hyun; Lee, Saseong; Choi, Susanna; Yoo, Seung-Ah; Park, Ji-Hwan; Hwang, Daehee; Shim, Seung Cheol; Sabbagh, Laurent; Kim, Ki-Jo; Park, Sung Hwan; Cho, Chul-Soo; Kim, Bong-Sung; Leng, Lin; Montgomery, Ruth R; Bucala, Richard; Chung, Yeun-Jun; Kim, Wan-Uk

    2015-11-24

    Copy number variations (CNVs) have been implicated in human diseases. However, it remains unclear how they affect immune dysfunction and autoimmune diseases, including rheumatoid arthritis (RA). Here, we identified a novel leukocyte-specific protein 1 (LSP1) deletion variant for RA susceptibility located in 11p15.5. We replicated that the copy number of LSP1 gene is significantly lower in patients with RA, which correlates positively with LSP1 protein expression levels. Differentially expressed genes in Lsp1-deficient primary T cells represent cell motility and immune and cytokine responses. Functional assays demonstrated that LSP1, induced by T-cell receptor activation, negatively regulates T-cell migration by reducing ERK activation in vitro. In mice with T-cell-dependent chronic inflammation, loss of Lsp1 promotes migration of T cells into the target tissues as well as draining lymph nodes, exacerbating disease severity. Moreover, patients with RA show diminished expression of LSP1 in peripheral T cells with increased migratory capacity, suggesting that the defect in LSP1 signaling lowers the threshold for T-cell activation. To our knowledge, our work is the first to demonstrate how CNVs result in immune dysfunction and a disease phenotype. Particularly, our data highlight the importance of LSP1 CNVs and LSP1 insufficiency in the pathogenesis of RA and provide previously unidentified insights into the mechanisms underlying T-cell migration toward the inflamed synovium in RA.

  20. Live-cell migration and adhesion turnover assays.

    PubMed

    Lacoste, J; Young, K; Brown, Claire M

    2013-01-01

    Fluorescence microscopy has revolutionized the way live-cell imaging is achieved. At the same time, it is also potentially harmful to a living specimen. Therefore, the specimen must be monitored for viability and health before, during, and after imaging sessions. Methods for monitoring cell viability and health will be discussed in this chapter. Another key to successful live-cell imaging is to minimize light exposure as much as possible. A summary of strategies for minimizing light exposure including maximizing the light throughput of the microscope and the sensitivity of light detection is presented. Various fluorescence microscopy techniques are presented with a focus on how the light is delivered to the sample (i.e., light density) and pros and cons for use with living specimens. The reader is also directed to other publications that go into these topics in more detail. Methods are described on how to prepare samples for single cell migration assays, how to measure cell migration rates (e.g., bright-field, semi-automated, and automated), and how to measure focal adhesion turnover rates. Details of how to correct images for background intensity and field-illumination uniformity artifacts for quantitative imaging are also described. Overall, this chapter will be helpful to scientists who are interested in imaging live specimens using fluorescence microscopy techniques. It will be of particular interest to anyone wanting to perform quantitative fluorescence imaging, and wanting to measure cell migration rates, and focal adhesion dynamics.

  1. Mutant huntingtin impairs immune cell migration in Huntington disease

    PubMed Central

    Kwan, Wanda; Träger, Ulrike; Davalos, Dimitrios; Chou, Austin; Bouchard, Jill; Andre, Ralph; Miller, Aaron; Weiss, Andreas; Giorgini, Flaviano; Cheah, Christine; Möller, Thomas; Stella, Nephi; Akassoglou, Katerina; Tabrizi, Sarah J.; Muchowski, Paul J.

    2012-01-01

    In Huntington disease (HD), immune cells are activated before symptoms arise; however, it is unclear how the expression of mutant huntingtin (htt) compromises the normal functions of immune cells. Here we report that primary microglia from early postnatal HD mice were profoundly impaired in their migration to chemotactic stimuli, and expression of a mutant htt fragment in microglial cell lines was sufficient to reproduce these deficits. Microglia expressing mutant htt had a retarded response to a laser-induced brain injury in vivo. Leukocyte recruitment was defective upon induction of peritonitis in HD mice at early disease stages and was normalized upon genetic deletion of mutant htt in immune cells. Migration was also strongly impaired in peripheral immune cells from pre-manifest human HD patients. Defective actin remodeling in immune cells expressing mutant htt likely contributed to their migration deficit. Our results suggest that these functional changes may contribute to immune dysfunction and neurodegeneration in HD, and may have implications for other polyglutamine expansion diseases in which mutant proteins are ubiquitously expressed. PMID:23160193

  2. 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.

  3. 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

  4. Pro-metastatic NEDD9 regulates individual cell migration via caveolin-1-dependent trafficking of integrins

    PubMed Central

    Kozyulina, Polina Y.; Loskutov, Yuriy V.; Kozyreva, Varvara K.; Rajulapati, Anuradha; Ice, Ryan J.; Jones, Brandon. C.; Pugacheva, Elena N.

    2014-01-01

    The dissemination of tumor cells relies on efficient cell adhesion and migration, which in turn depends upon endocytic trafficking of integrins. In the current work, it was found that depletion of pro-metastatic protein, NEDD9, in breast cancer (BC) cells results in a significant decrease in individual cell migration due to impaired trafficking of ligand-bound integrins. NEDD9 deficiency does not affect the expression or internalization of integrins but heightens caveolae-dependent trafficking of ligand-bound integrins to early endosomes. Increase in mobility of ligand-bound integrins is concomitant with an increase in tyrosine phosphorylation of caveolin-1 (CAV1) and volume of CAV1-vesicles. NEDD9 directly binds to CAV1 and co-localizes within CAV1 vesicles. In the absence of NEDD9, the trafficking of ligand-bound integrins from early to late endosomes is impaired, resulting in a significant decrease in degradation of ligand/integrin complexes and an increase in recycling of ligand-bound integrins from early endosomes back to the plasma membrane without ligand disengagement, thus leading to low adhesion and migration. Re-expression of NEDD9 or decrease in the amount of active, tyrosine 14 phosphorylated (Tyr14) CAV1 in NEDD9 depleted cells rescues the integrin trafficking deficiency and restores cellular adhesion and migration capacity. Collectively, these findings indicate that NEDD9 orchestrates trafficking of ligand-bound integrins through the attenuation of CAV1 activity. PMID:25319010

  5. 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

  6. DISC1 knockdown impairs the tangential migration of cortical interneurons by affecting the actin cytoskeleton

    PubMed Central

    Steinecke, André; Gampe, Christin; Nitzsche, Falk; Bolz, Jürgen

    2014-01-01

    Disrupted-in-Schizophrenia 1 (DISC1) is a risk gene for a spectrum of major mental disorders. It has been shown to regulate radial migration as well as dendritic arborization during neurodevelopment and corticogenesis. In a previous study we demonstrated through in vitro experiments that DISC1 also controls the tangential migration of cortical interneurons originating from the medial ganglionic eminence (MGE). Here we first show that DISC1 is necessary for the proper tangential migration of cortical interneurons in the intact brain. Expression of EGFP under the Lhx6 promotor allowed us to analyze exclusively interneurons transfected in the MGE after in utero electroporation. After 3 days in utero, DISC1 deficient interneurons displayed prolonged leading processes and, compared to control, fewer neurons reached the cortex. Time-lapse video microscopy of cortical feeder-layers revealed a decreased migration velocity due to a reduction of soma translocations. Immunostainings indicated that DISC1 is co-localized with F-actin in the growth cone-like structure of the leading process. DISC1 knockdown reduced F-actin levels whereas the overall actin level was not altered. Moreover, DISC1 knockdown also decreased levels of phosphorylated Girdin, which cross-links F-actin, as well as the Girdin-activator pAkt. In contrast, using time-lapse video microscopy of fluorescence-tagged tubulin and EB3 in fibroblasts, we found no effects on microtubule polymerization when DISC1 was reduced. However, DISC1 affected the acetylation of microtubules in the leading processes of MGE-derived cortical interneurons. Together, our results provide a mechanism how DISC1 might contribute to interneuron migration thereby explaining the reduced number of specific classes of cortical interneurons in some DISC1 mouse models. PMID:25071449

  7. Cell migration and invasion assays as tools for drug discovery.

    PubMed

    Hulkower, Keren I; Herber, Renee L

    2011-03-11

    Cell migration and invasion are processes that offer rich targets for intervention in key physiologic and pathologic phenomena such as wound healing and cancer metastasis. With the advent of high-throughput and high content imaging systems, there has been a movement towards the use of physiologically relevant cell-based assays earlier in the testing paradigm. This allows more effective identification of lead compounds and recognition of undesirable effects sooner in the drug discovery screening process. This article will review the effective use of several principle formats for studying cell motility: scratch assays, transmembrane assays, microfluidic devices and cell exclusion zone assays.

  8. 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.

  9. 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

  10. Muc1 promotes migration and lung metastasis of melanoma cells

    PubMed Central

    Wang, Xiaoli; Lan, Hongwen; Li, Jun; Su, Yushu; Xu, Lijun

    2015-01-01

    Early stages of melanoma can be successfully treated by surgical resection of the tumor, but there is still no effective treatment once it is progressed to metastatic phases. Although growing family of both melanoma metastasis promoting and metastasis suppressor genes have been reported be related to metastasis, the molecular mechanisms governing melanoma metastatic cascade are still not completely understood. Therefore, defining the molecules that govern melanoma metastasis may aid the development of more effective therapeutic strategies for combating melanoma. In the present study, we found that muc1 is involved in the metastasis of melanoma cells and demonstrated that muc1 disruption impairs melanoma cells migration and metastasis. The requirement of muc1 in the migration of melanoma cells was further confirmed by gene silencing in vitro. In corresponding to this result, over-expression of muc1 significantly promoted the migratory of melanoma cells. Moreover, down-regulation of muc1 expression strikingly inhibits melanoma cellular metastasis in vivo. Finally, we found that muc1 promotes melanoma migration through the protein kinase B (Akt) signaling pathway. To conclude, our findings suggest a novel mechanism underlying the metastasis of melanoma cells which might serve as a new intervention target for the treatment of melanoma. PMID:26609470

  11. 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

  12. Cell volume regulatory ion transport in the regulation of cell migration.

    PubMed

    Jakab, M; Ritter, M

    2006-01-01

    Cell migration is typically accomplished by the generation of protrusive mechanical forces and is achieved by repeated spatially and temporally coordinated cycles including the formation of a leading edge, the formation of new and disruption of older adhesions to the substratum, actomyosin based contractions and retraction of the trailing edge. Beside the well-described roles of the cytoskeleton and cell adhesions during these processes, a growing body of evidence indicates that the precise regulation of the cell volume is an indispensable prerequisite for coordinated cell migration. On the one hand during cell migration cell volume is continuously tormented by mechanical and morphological alterations, which pose changes to the intracellular hydrostatic pressure, metabolic changes and the formation or degradation of macromolecules like actin, which distort the osmotic equilibrium and the action of chemoattractants, hormones and transmitters, which frequently alter the electrical properties of a cell and thus cause cell swelling or shrinkage, respectively. On the other hand, a migrating cell actively has to govern cell volume regulatory ion transport mechanisms in order to create the appropriate micro- or even nanoenvironment in the intra- and/or extracellular space, which is necessary to guarantee the correct polarity and hence direction of movement of a migrating cell. This chapter will focus on the role of the cell volume regulatory ion transport mechanisms as they participate in the regulation of cell migration and special emphasis is given to their interplay with the cytoskeleton, their meaning for substrate adhesion and to the polarized fashion of their subcellular distribution.

  13. Ion channels in control of pancreatic stellate cell migration

    PubMed Central

    Storck, Hannah; Hild, Benedikt; Schimmelpfennig, Sandra; Sargin, Sarah; Nielsen, Nikolaj; Zaccagnino, Angela; Budde, Thomas; Novak, Ivana; Kalthoff, Holger; Schwab, Albrecht

    2017-01-01

    Pancreatic stellate cells (PSCs) play a critical role in the progression of pancreatic ductal adenocarcinoma (PDAC). Once activated, PSCs support proliferation and metastasis of carcinoma cells. PSCs even co-metastasise with carcinoma cells. This requires the ability of PSCs to migrate. In recent years, it has been established that almost all “hallmarks of cancer” such as proliferation or migration/invasion also rely on the expression and function of ion channels. So far, there is only very limited information about the function of ion channels in PSCs. Yet, there is growing evidence that ion channels in stromal cells also contribute to tumor progression. Here we investigated the function of KCa3.1 channels in PSCs. KCa3.1 channels are also found in many tumor cells of different origin. We revealed the functional expression of KCa3.1 channels by means of Western blot, immunofluorescence and patch clamp analysis. The impact of KCa3.1 channel activity on PSC function was determined with live-cell imaging and by measuring the intracellular Ca2+ concentration ([Ca2+]i). KCa3.1 channel blockade or knockout prevents the stimulation of PSC migration and chemotaxis by reducing the [Ca2+]i and calpain activity. KCa3.1 channels functionally cooperate with TRPC3 channels that are upregulated in PDAC stroma. Knockdown of TRPC3 channels largely abolishes the impact of KCa3.1 channels on PSC migration. In summary, our results clearly show that ion channels are crucial players in PSC physiology and pathophysiology. PMID:27903970

  14. Regulation of turkey myogenic satellite cell migration by MicroRNAs miR-128 and miR-24.

    PubMed

    Velleman, S G; Harding, R L

    2016-12-05

    Myogenic satellite cells are an adult stem cell responsible for all post-hatch muscle growth in poultry. As a stem cell population, satellite cells are highly heterogeneous, but the origin of this heterogeneity remains unclear. Heterogeneity is, in part, regulated by gene expression. One method of endogenous gene regulation that may contribute to heterogeneity is microRNAs (miRNAs). Two miRNAs previously shown to regulate poultry myogenic satellite cell proliferation and differentiation, miR-128 and miR-24, were studied to determine if they also affected satellite cell migration. Satellite cell migration is an essential step for both proliferation and differentiation. During proliferation, satellite cells will migrate and align to form new myofibers or donate their nuclei to existing myofibers leading to muscle fiber hypertrophy or regeneration. Transient transfection of miRNA specific mimics to each miRNA reduced migration of satellite cells following a cell culture scratch at 72 h of proliferation when the cultures were 90 to 100% confluent. However, only the migration in cells transfected with miR-24 mimics at 24 and 30 h following the scratch was significantly reduced (P ≤ 0.05) to around 70% of the distance migrated by controls. Alternately, transfection with inhibitors specific to miR-128 or miR-24 significantly (P ≤ 0.05) increased migration between 147 and 252% compared to their controls between 24 and 48 h following the scratch. These data demonstrate that miR-128 and miR-24 play a role in myogenic satellite cell migration, which will impact muscle development and growth.

  15. 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.

  16. Endothelial cell migration on surfaces modified with immobilized adhesive peptides.

    PubMed

    Kouvroukoglou, S; Dee, K C; Bizios, R; McIntire, L V; Zygourakis, K

    2000-09-01

    Endothelial cell (EC) migration has been studied on aminophase surfaces with covalently bound RGDS and YIGSRG cell adhesion peptides. The fluorescent marker dansyl chloride was used to quantify the spatial distribution of the peptides on the modified surfaces. Peptides appeared to be distributed in uniformly dispersed large clusters separated by areas of lower peptide concentrations. We employed digital time-lapse video microscopy and image analysis to monitor EC migration on the modified surfaces and to reconstruct the cell trajectories. The persistent random walk model was then applied to analyze the cell displacement data and compute the mean root square speed, the persistence time, and the random motility coefficient of EC. We also calculated the time-averaged speed of cell locomotion. No differences in the speed of cell locomotion on the various substrates were noted. Immobilization of the cell adhesion peptides (RGDS and YIGSRG), however, significantly increased the persistence of cell movement and, thus, the random motility coefficient. These results suggest that immobilization of cell adhesion peptides on the surface of implantable biomaterials may lead to enhanced endothelization rates.

  17. Control of glioma cell migration and invasiveness by GDF-15.

    PubMed

    Codó, Paula; Weller, Michael; Kaulich, Kerstin; Schraivogel, Daniel; Silginer, Manuela; Reifenberger, Guido; Meister, Gunter; Roth, Patrick

    2016-02-16

    Growth and differentiation factor (GDF)-15 is a member of the transforming growth factor (TGF)-β family of proteins. GDF-15 levels are increased in the blood and cerebrospinal fluid of glioblastoma patients. Using a TCGA database interrogation, we demonstrate that high GDF-15 expression levels are associated with poor survival of glioblastoma patients. To elucidate the role of GDF-15 in glioblastoma in detail, we confirmed that glioma cells express GDF-15 mRNA and protein in vitro. To allow for a detailed functional characterization, GDF-15 expression was silenced using RNA interference in LNT-229 and LN-308 glioma cells. Depletion of GDF-15 had no effect on cell viability. In contrast, GDF-15-deficient cells displayed reduced migration and invasion, in the absence of changes in Smad2 or Smad1/5/8 phosphorylation. Conversely, exogenous GDF-15 stimulated migration and invasiveness. Large-scale expression profiling revealed that GDF-15 gene silencing resulted in minor changes in the miRNA profile whereas several genes, including members of the plasminogen activator/inhibitor complex, were deregulated at the mRNA level. One of the newly identified genes induced by GDF-15 gene silencing was the serpin peptidase inhibitor, clade E nexin group 1 (serpine1) which is induced by TGF-β and known to inhibit migration and invasiveness. However, serpine1 down-regulation alone did not mediate GDF-15-induced promotion of migration and invasiveness. Our findings highlight the complex contributions of GDF-15 to the invasive phenotype of glioma cells and suggest anti-GDF-15 approaches as a promising therapeutic strategy.

  18. Control of glioma cell migration and invasiveness by GDF-15

    PubMed Central

    Codó, Paula; Weller, Michael; Kaulich, Kerstin; Schraivogel, Daniel; Silginer, Manuela; Reifenberger, Guido; Meister, Gunter; Roth, Patrick

    2016-01-01

    Growth and differentiation factor (GDF)-15 is a member of the transforming growth factor (TGF)-β family of proteins. GDF-15 levels are increased in the blood and cerebrospinal fluid of glioblastoma patients. Using a TCGA database interrogation, we demonstrate that high GDF-15 expression levels are associated with poor survival of glioblastoma patients. To elucidate the role of GDF-15 in glioblastoma in detail, we confirmed that glioma cells express GDF-15 mRNA and protein in vitro. To allow for a detailed functional characterization, GDF-15 expression was silenced using RNA interference in LNT-229 and LN-308 glioma cells. Depletion of GDF-15 had no effect on cell viability. In contrast, GDF-15-deficient cells displayed reduced migration and invasion, in the absence of changes in Smad2 or Smad1/5/8 phosphorylation. Conversely, exogenous GDF-15 stimulated migration and invasiveness. Large-scale expression profiling revealed that GDF-15 gene silencing resulted in minor changes in the miRNA profile whereas several genes, including members of the plasminogen activator/inhibitor complex, were deregulated at the mRNA level. One of the newly identified genes induced by GDF-15 gene silencing was the serpin peptidase inhibitor, clade E nexin group 1 (serpine1) which is induced by TGF-β and known to inhibit migration and invasiveness. However, serpine1 down-regulation alone did not mediate GDF-15-induced promotion of migration and invasiveness. Our findings highlight the complex contributions of GDF-15 to the invasive phenotype of glioma cells and suggest anti-GDF-15 approaches as a promising therapeutic strategy. PMID:26741507

  19. HMG-CoA reductase guides migrating primordial germ cells.

    PubMed

    Van Doren, M; Broihier, H T; Moore, L A; Lehmann, R

    1998-12-03

    The enzyme 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase is best known for catalysing a rate-limiting step in cholesterol biosynthesis, but it also participates in the production of a wide variety of other compounds. Some clinical benefits attributed to inhibitors of HMG-CoA reductase are now thought to be independent of any serum cholesterol-lowering effect. Here we describe a new cholesterol-independent role for HMG-CoA reductase, in regulating a developmental process: primordial germ cell migration. We show that in Drosophila this enzyme is highly expressed in the somatic gonad and that it is necessary for primordial germ cells to migrate to this tissue. Misexpression of HMG-CoA reductase is sufficient to attract primordial germ cells to tissues other than the gonadal mesoderm. We conclude that the regulated expression of HMG-CoA reductase has a critical developmental function in providing spatial information to guide migrating primordial germ cells.

  20. Forces, waves and emergent dynamics during collective cell migration

    NASA Astrophysics Data System (ADS)

    Trepat, Xavier

    2013-03-01

    A broad range of biological processes such as morphogenesis, tissue regeneration, and cancer invasion depend on the collective motion of cell groups. For a group of cells to migrate cohesively, it has long been suspected that each constituent cell must exert physical forces not only upon its extracellular matrix but also upon neighboring cells. I will present novel techniques to measure these distinct force components. Using these techniques, we unveiled an unexpectedly rich physical picture in which the distribution of physical forces is dominated by heterogeneity, cooperativity, and jamming. I will show, moreover, that these essential features of inter-cellular force transmission enable the propagation of a new type of mechanical wave during tissue growth. Finally, I will demonstrate that both in epithelial and endothelial cell sheets, forces and waves are mechanically linked to cell velocities through a newly discovered emergent mechanism of innately collective cell guidance: plithotaxis.

  1. Studying Neutrophil Migration In Vivo Using Adoptive Cell Transfer.

    PubMed

    Miyabe, Yoshishige; Kim, Nancy D; Miyabe, Chie; Luster, Andrew D

    2016-01-01

    Adoptive cell transfer experiments can be used to study the roles of cell trafficking molecules on the migratory behavior of specific immune cell populations in vivo. Chemoattractants and their G protein-coupled seven-transmembrane-spanning receptors regulate migration of cells in vivo, and dysregulated expression of chemoattractants and their receptors is implicated in autoimmune and inflammatory diseases. Inflammatory arthritides, such as rheumatoid arthritis (RA), are characterized by the recruitment of inflammatory cells into joints. The K/BxN serum transfer mouse model of inflammatory arthritis shares many similar features with RA. In this autoantibody-induced model of arthritis, neutrophils are the critical immune cells necessary for the development of joint inflammation and damage. We have used adoptive neutrophil transfer to define the contributions of chemoattractant receptors, cytokines, and activation receptors expressed on neutrophils that critically regulate their entry into the inflamed joint. In this review, we describe the procedure of neutrophil adoptive transfer to study the influence of neutrophil-specific receptors or mediators upon the their recruitment into the joint using the K/BxN model of inflammatory arthritis as a model of how adoptive cell transfer studies can be used to study immune cell migration in vivo.

  2. Intermediate filament reorganization dynamically influences cancer cell alignment and migration

    PubMed Central

    Holle, Andrew W.; Kalafat, Melih; Ramos, Adria Sales; Seufferlein, Thomas; Kemkemer, Ralf; Spatz, Joachim P.

    2017-01-01

    The interactions between a cancer cell and its extracellular matrix (ECM) have been the focus of an increasing amount of investigation. The role of the intermediate filament keratin in cancer has also been coming into focus of late, but more research is needed to understand how this piece fits in the puzzle of cytoskeleton-mediated invasion and metastasis. In Panc-1 invasive pancreatic cancer cells, keratin phosphorylation in conjunction with actin inhibition was found to be sufficient to reduce cell area below either treatment alone. We then analyzed intersecting keratin and actin fibers in the cytoskeleton of cyclically stretched cells and found no directional correlation. The role of keratin organization in Panc-1 cellular morphological adaptation and directed migration was then analyzed by culturing cells on cyclically stretched polydimethylsiloxane (PDMS) substrates, nanoscale grates, and rigid pillars. In general, the reorganization of the keratin cytoskeleton allows the cell to become more ‘mobile’- exhibiting faster and more directed migration and orientation in response to external stimuli. By combining keratin network perturbation with a variety of physical ECM signals, we demonstrate the interconnected nature of the architecture inside the cell and the scaffolding outside of it, and highlight the key elements facilitating cancer cell-ECM interactions. PMID:28338091

  3. The NANIVID: a new device for cancer cell migration studies

    NASA Astrophysics Data System (ADS)

    Raja, Waseem K.; Cady, Nathaniel C.; Castracane, James; Gligorijevic, Bojana; van Rheenen, Jacobus W.; Condeelis, John S.

    2008-02-01

    Cancerous tumors are dynamic microenvironments that require unique analytical tools for their study. Better understanding of tumor microenvironments may reveal mechanisms behind tumor progression and generate new strategies for diagnostic marker development, which can be used routinely in histopathological analysis. Previous studies have shown that cell invasion and intravasation are related to metastatic potential and have linked these activities to gene expression patterns seen in migratory and invasive tumor cells in vivo. Existing analytical methods for tumor microenvironments include collection of tumor cells through a catheter needle loaded with a chemical or protein attractant (chemoattractant). This method has some limitations and restrictions, including time constraints of cell collection, long term anesthetization, and in vivo imaging inside the catheter. In this study, a novel implantable device was designed to replace the catheter-based method. The 1.5mm x 0.5mm x 0.24mm device is designed to controllably release chemoattractants for stimulation of tumor cell migration and subsequent cell capture. Devices were fabricated using standard microfabrication techniques and have been shown to mediate controlled release of bovine serum albumin (BSA) and epidermal growth factor (EGF). Optically transparent indium tin oxide (ITO) electrodes have been incorporated into the device for impedance-based measurement of cell density and have been shown to be compatible with in vivo multi-photon imaging of cell migration.

  4. Rutin inhibits proliferation, attenuates superoxide production and decreases adhesion and migration of human cancerous cells.

    PubMed

    Ben Sghaier, Mohamed; Pagano, Alessandra; Mousslim, Mohamed; Ammari, Youssef; Kovacic, Hervé; Luis, José

    2016-12-01

    Lung and colorectal cancer are the principal causes of death in the world. Rutin, an active flavonoid compound, is known for possessing a wide range of biological activities. In this study, we examined the effect of rutin on the viability, superoxide anion production, adhesion and migration of human lung (A549) and colon (HT29 and Caco-2) cancer cell lines. In order to control the harmlessness of the tested concentrations of rutin, the viability of cancer cell lines was assessed using a 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. ROS generation was measured by lucigenin chemiluminescence detecting superoxide ions. To investigate the effect of rutin on the behavior of human lung and colon cancer cell lines, we performed adhesion assays, using various purified extracellular matrix (ECM) proteins. Finally, in vitro cell migration assays were explored using modified Boyden chambers. The viability of cancerous cells was inhibited by rutin. It also significantly attenuated the superoxide production in HT29 cells. In addition, rutin affected adhesion and migration of A549 and HT29 cell. These findings indicate that rutin, a natural molecule, might have potential as anticancer agent against lung and colorectal carcinogenesis.

  5. FH535 inhibited migration and growth of breast cancer cells.

    PubMed

    Iida, Joji; Dorchak, Jesse; Lehman, John R; Clancy, Rebecca; Luo, Chunqing; Chen, Yaqin; Somiari, Stella; Ellsworth, Rachel E; Hu, Hai; Mural, Richard J; Shriver, Craig D

    2012-01-01

    There is substantial evidence indicating that the WNT signaling pathway is activated in various cancer cell types including breast cancer. Previous studies reported that FH535, a small molecule inhibitor of the WNT signaling pathway, decreased growth of cancer cells but not normal fibroblasts, suggesting this pathway plays a role in tumor progression and metastasis. In this study, we tested FH535 as a potential inhibitor for malignant phenotypes of breast cancer cells including migration, invasion, and growth. FH535 significantly inhibited growth, migration, and invasion of triple negative (TN) breast cancer cell lines (MDA-MB231 and HCC38) in vitro. We demonstrate that FH535 was a potent growth inhibitor for TN breast cancer cell lines (HCC38 and MDA-MB-231) but not for other, non-TN breast cancer cell lines (MCF-7, T47D or SK-Br3) when cultured in three dimensional (3D) type I collagen gels. Western blotting analyses suggest that treatment of MDA-MB-231 cells with FH535 markedly inhibited the expression of NEDD9 but not activations of FAK, Src, or downstream targets such as p38 and Erk1/2. We demonstrated that NEDD9 was specifically associated with CSPG4 but not with β1 integrin or CD44 in MDA-MB-231 cells. Analyses of gene expression profiles in breast cancer tissues suggest that CSPG4 expression is higher in Basal-type breast cancers, many of which are TN, than any other subtypes. These results suggest not only a mechanism for migration and invasion involving the canonical WNT-signaling pathways but also novel strategies for treating patients who develop TN breast cancer.

  6. Angiotensin Converting Enzyme Regulates Cell Proliferation and Migration

    PubMed Central

    Carvalho, Clarissa Coelho; Florentino, Rodrigo Machado; França, Andressa; Matias, Eveline; Guimarães, Paola Bianchi; Batista, Carolina; Freire, Valder; Carmona, Adriana Karaoglanovic; Pesquero, João Bosco; de Paula, Ana Maria; Foureaux, Giselle; Leite, Maria de Fatima

    2016-01-01

    Background The angiotensin-I converting enzyme (ACE) plays a central role in the renin-angiotensin system, acting by converting the hormone angiotensin-I to the active peptide angiotensin-II (Ang-II). More recently, ACE was shown to act as a receptor for Ang-II, and its expression level was demonstrated to be higher in melanoma cells compared to their normal counterparts. However, the function that ACE plays as an Ang-II receptor in melanoma cells has not been defined yet. Aim Therefore, our aim was to examine the role of ACE in tumor cell proliferation and migration. Results We found that upon binding to ACE, Ang-II internalizes with a faster onset compared to the binding of Ang-II to its classical AT1 receptor. We also found that the complex Ang-II/ACE translocates to the nucleus, through a clathrin-mediated process, triggering a transient nuclear Ca2+ signal. In silico studies revealed a possible interaction site between ACE and phospholipase C (PLC), and experimental results in CHO cells, demonstrated that the β3 isoform of PLC is the one involved in the Ca2+ signals induced by Ang-II/ACE interaction. Further studies in melanoma cells (TM-5) showed that Ang-II induced cell proliferation through ACE activation, an event that could be inhibited either by ACE inhibitor (Lisinopril) or by the silencing of ACE. In addition, we found that stimulation of ACE by Ang-II caused the melanoma cells to migrate, at least in part due to decreased vinculin expression, a focal adhesion structural protein. Conclusion ACE activation regulates melanoma cell proliferation and migration. PMID:27992423

  7. 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.

  8. 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

  9. Migration and Tissue Tropism of Innate Lymphoid Cells

    PubMed Central

    Kim, Chang H.; Hashimoto-Hill, Seika; Kim, Myunghoo

    2016-01-01

    Innate lymphoid cell (ILCs) subsets differentially populate various barrier and non-barrier tissues, where they play important roles in tissue homeostasis and tissue-specific responses to pathogen attack. Recent findings have provided insight into the molecular mechanisms that guide ILC migration into peripheral tissues, revealing common features among different ILC subsets as well as important distinctions. Recent studies have also highlighted the impact of tissue-specific cues on ILC migration, and the importance of the local immunological milieu. We review these findings here and discuss how the migratory patterns and tissue tropism of different ILC subsets relate to the development and differentiation of these cells, and to ILC-mediated tissue-specific regulation of innate and adaptive immune responses. In this context we outline open questions and important areas of future research. PMID:26708278

  10. Cathepsin L derived from skeletal muscle cells transfected with bFGF promotes endothelial cell migration.

    PubMed

    Chung, Ji Hyung; Im, Eun Kyoung; Jin, Tae Won; Lee, Seung-Min; Kim, Soo Hyuk; Choi, Eun Young; Shin, Min-Jeong; Lee, Kyung Hye; Jang, Yangsoo

    2011-04-30

    Gene transfer of basic fibroblast growth factor (bFGF) has been shown to induce significant endothelial migration and angiogenesis in ischemic disease models. Here, we investigate what factors are secreted from skeletal muscle cells (SkMCs) transfected with bFGF gene and whether they participate in endothelial cell migration. We constructed replication-defective adenovirus vectors containing the human bFGF gene (Ad/bFGF) or a control LacZ gene (Ad/LacZ) and obtained conditioned media, bFGF-CM and LacZ-CM, from SkMCs infected by Ad/bFGF or Ad/LacZ, respectively. Cell migration significantly increased in HUVECs incubated with bFGF-CM compared to cells incubated with LacZ-CM. Interestingly, HUVEC migration in response to bFGF-CM was only partially blocked by the addition of bFGF-neutralizing antibody, suggesting that bFGF-CM contains other factors that stimulate endothelial cell migration. Several proteins, matrix metalloproteinase-1 (MMP-1), plasminogen activator inhibitor-1 (PAI-1), and cathepsin L, increased in bFGF-CM compared to LacZ-CM; based on 1-dimensional gel electrophoresis and mass spectrometry. Their increased mRNA and protein levels were confirmed by RT-PCR and immunoblot analysis. The recombinant human bFGF protein induced MMP-1, PAI-1, and cathepsin L expression in SkMCs. Endothelial cell migration was reduced in groups treated with bFGF-CM containing neutralizing antibodies against MMP-1 or PAI-1. In particular, HUVECs treated with bFGF-CM containing cell-impermeable cathepsin L inhibitor showed the most significant decrease in cell migration. Cathepsin L protein directly promotes endothelial cell migration through the JNK pathway. These results indicate that cathepsin L released from SkMCs transfected with the bFGF gene can promote endothelial cell migration.

  11. Analysis of individual cell trajectories in lattice-gas cellular automaton models for migrating cell populations.

    PubMed

    Mente, Carsten; Voss-Böhme, Anja; Deutsch, Andreas

    2015-04-01

    Collective dynamics of migrating cell populations drive key processes in tissue formation and maintenance under normal and diseased conditions. Collective cell behavior at the tissue level is typically characterized by considering cell density patterns such as clusters and moving cell fronts. However, there are also important observables of collective dynamics related to individual cell behavior. In particular, individual cell trajectories are footprints of emergent behavior in populations of migrating cells. Lattice-gas cellular automata (LGCA) have proven successful to model and analyze collective behavior arising from interactions of migrating cells. There are well-established methods to analyze cell density patterns in LGCA models. Although LGCA dynamics are defined by cell-based rules, individual cells are not distinguished. Therefore, individual cell trajectories cannot be analyzed in LGCA so far. Here, we extend the classical LGCA framework to allow labeling and tracking of individual cells. We consider cell number conserving LGCA models of migrating cell populations where cell interactions are regulated by local cell density and derive stochastic differential equations approximating individual cell trajectories in LGCA. This result allows the prediction of complex individual cell trajectories emerging in LGCA models and is a basis for model-experiment comparisons at the individual cell level.

  12. Homing and migration assays of hematopoietic stem/progenitor cells.

    PubMed

    He, Xi C; Li, Zhenrui; Sugimura, Rio; Ross, Jason; Zhao, Meng; Li, Linheng

    2014-01-01

    Hematopoietic stem and progenitor cells (HSPCs) reside mainly in bone marrow; however, under homeostatic and stressed conditions, HSPCs dynamically change their location-either egressing from bone marrow and getting into circulation, a process of mobilization; or coming back to the bone marrow, the homing process. How to analyze these two processes will be critical for understanding the behavior of HSPCs. Here we provide an experimental protocol to monitor and analyze homing and migration of HSPCs.

  13. 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

  14. Pancreatic tumor cell secreted CCN1/Cyr61 promotes endothelial cell migration and aberrant neovascularization.

    PubMed

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

    2014-05-16

    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.

  15. Common mechanisms regulating cell cortex properties during cell division and cell migration.

    PubMed

    Roubinet, Chantal; Tran, Phong T; Piel, Matthieu

    2012-11-01

    Single cell morphogenesis results from a balance of forces involving internal pressure (also called turgor pressure in plants and fungi) and the plastic and dynamic outer shell of the cell. Dominated by the cell wall in plants and fungi, mechanical properties of the outer shell of animal cells arise from the cell cortex, which is mostly composed of the plasma membrane (and membrane proteins) and the underlying meshwork of actin filaments and myosin motors (and associated proteins). In this review, following Bray and White [1988; Science 239:883-889], we draw a parallel between the regulation of the cell cortex during cell division and cell migration in animal cells. Starting from the similarities in shape changes and underlying mechanical properties, we further propose that the analogy between cell division and cell migration might run deeper, down to the basic molecular mechanisms driving cell cortex remodeling. We focus our attention on how an heterogeneous and dynamic cortex can be generated to allow cell shape changes while preserving cell integrity.

  16. N-cadherin as a key regulator of collective cell migration in a 3D environment.

    PubMed

    Shih, Wenting; Yamada, Soichiro

    2012-01-01

    Cell migration is a critical step of normal developmental processes and disease progression. Often, migrating cells interact and maintain contact with neighboring cells. However, the precise roles of cell-cell adhesion in cell migration have thus far been poorly defined. Often in aggressive cancers, N-cadherin is prominently upregulated, yet, these highly motile cells have limited cell-cell adhesion when plated on a stiff 2D substrate. But, the same cells in a 3D matrix migrate as a multicellular cluster. This new observation suggests that N-cadherin-mediated cell-cell adhesion supports cell interactions between migrating cells in a more physiologically relevant 3D matrix, but not on a 2D substrate. While N-cadherin is an integral part of neural synapses, the ectopic expression of N-cadherin in transformed epithelial cells plays an equally important part in initiating pro-migratory signaling, and providing strong yet flexible cell cohesion essential for persistent cell migration in a 3D matrix. The 3D cell migration analysis for studying cell-to-cell interactions exposes the roles of N-cadherin in multicellular migration, and reveals novel insights into cell migration-dependent normal and pathological processes.

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

    PubMed

    Qi, Zhi-Ping; Wang, Guo-Xiang; Xia, Peng; Hou, Ting-Ting; Zhou, Hong-Li; Wang, Tie-Jun; Yang, Xiao-Yu

    2016-02-01

    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.

  18. Methylene blue modulates transendothelial migration of peripheral blood cells.

    PubMed

    Werner, Isabella; Guo, Fengwei; Bogert, Nicolai V; Stock, Ulrich A; Meybohm, Patrick; Moritz, Anton; Beiras-Fernandez, Andres

    2013-01-01

    Vasoplegia is a severe complication after cardiac surgery. Within the last years the administration of nitric oxide synthase inhibitor methylene blue (MB) became a new therapeutic strategy. Our aim was to investigate the role of MB on transendothelial migration of circulating blood cells, the potential role of cyclic cGMP, eNOS and iNOS in this process, and the influence of MB on endothelial cell apoptosis. Human vascular endothelial cells (HuMEC-1) were treated for 30 minutes or 2 hours with different concentrations of MB. Inflammation was mimicked by LPS stimulation prior and after MB. Transmigration of PBMCs and T-Lymphocytes through the treated endothelial cells was investigated. The influence of MB upon the different subsets of PBMCs (Granulocytes, T- and B-Lymphocytes, and Monocytes) was assessed after transmigration by means of flow-cytometry. The effect of MB on cell apoptosis was evaluated using Annexin-V and Propidium Iodide stainings. Analyses of the expression of cyclic cGMP, eNOS and iNOS were performed by means of RT-PCR and Western Blot. Results were analyzed using unpaired Students T-test. Analysis of endothelial cell apoptosis by MB indicated a dose-dependent increase of apoptotic cells. We observed time- and dose-dependent effects of MB on transendothelial migration of PBMCs. The prophylactic administration of MB led to an increase of transendothelial migration of PBMCs but not Jurkat cells. Furthermore, HuMEC-1 secretion of cGMP correlated with iNOS expression after MB administration but not with eNOS expression. Expression of these molecules was reduced after MB administration at protein level. This study clearly reveals that endothelial response to MB is dose- and especially time-dependent. MB shows different effects on circulating blood cell-subtypes, and modifies the release patterns of eNOS, iNOS, and cGMP. The transendothelial migration is modulated after treatment with MB. Furthermore, MB provokes apoptosis of endothelial cells in a dose

  19. STRIPAK components determine mode of cancer cell migration and metastasis

    PubMed Central

    Madsen, Chris D.; Hooper, Steven; Tozluoglu, Melda; Bruckbauer, Andreas; Fletcher, Georgina; Erler, Janine T.; Bates, Paul A.; Thompson, Barry; Sahai, Erik

    2017-01-01

    The contractile actomyosin cytoskeleton and its connection to the plasma membrane are critical for control of cell shape and migration. We identify three STRIPAK complex components, FAM40A, FAM40B, and STRN3, as regulators of the actomyosin cortex. We show that FAM40A negatively regulates the MST3 and MST4 kinases, which promote the co-localisation of the contractile actomyosin machinery with the Ezrin/Radixin/Moesin family proteins by phosphorylating the inhibitors of PPP1CB, PPP1R14A-D. Using computational modelling, in vitro cell migration assays and in vivo breast cancer metastasis assays we demonstrate that co-localisation of contractile activity and actin-plasma membrane linkage reduces cell speed on planar surfaces, but favours migration in confined environments similar to those observed in vivo. We further show that FAM40B mutations found in human tumours uncouple it from PP2A and enable it to drive a contractile phenotype, which may underlie its role in human cancer. PMID:25531779

  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. Tumor treating fields inhibit glioblastoma cell migration, invasion and angiogenesis

    PubMed Central

    Kim, Eun Ho; Song, Hyo Sook; Yoo, Seung Hoon; Yoon, Myonggeun

    2016-01-01

    Treatment with alternating electric fields at an intermediate frequency (100–300 kHz), referred to as tumor treating fields (TTF) therapy, inhibits cancer cell proliferation. In the present study, we demonstrated that TTF application suppressed the metastatic potential of U87 and U373 glioblastoma cell lines via the NF-kB, MAPK and PI3K/AKT signaling pathways. Wound-healing and transwell assays showed that TTF suppressed cell migration and invasion compared with controls. Soft agar and three-dimensional culture assays showed that TTF inhibited both anchorage-dependent (cell proliferation) and anchorage-independent (colony formation) GBM cell growth. TTF dysregulated epithelial-to-mesenchymal transition-related genes, such as vimentin and E-cadherin, which partially accounted for TTF inhibition of cell migration and invasion. We further demonstrated that TTF application suppressed angiogenesis by downregulating VEGF, HIF1α and matrix metalloproteinases 2 and 9. TTF also inhibited NF-kB transcriptional activity. Collectively, our findings show that TTF represents a promising novel anti-invasion and anti-angiogenesis therapeutic strategy for use in GBM patients. PMID:27556184

  3. 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.

  4. Sensitivity of edge detection methods for quantifying cell migration assays.

    PubMed

    Treloar, Katrina K; Simpson, Matthew J

    2013-01-01

    Quantitative imaging methods to analyze cell migration assays are not standardized. Here we present a suite of two-dimensional barrier assays describing the collective spreading of an initially-confined population of 3T3 fibroblast cells. To quantify the motility rate we apply two different automatic image detection methods to locate the position of the leading edge of the spreading population after 24, 48 and 72 hours. These results are compared with a manual edge detection method where we systematically vary the detection threshold. Our results indicate that the observed spreading rates are very sensitive to the choice of image analysis tools and we show that a standard measure of cell migration can vary by as much as 25% for the same experimental images depending on the details of the image analysis tools. Our results imply that it is very difficult, if not impossible, to meaningfully compare previously published measures of cell migration since previous results have been obtained using different image analysis techniques and the details of these techniques are not always reported. Using a mathematical model, we provide a physical interpretation of our edge detection results. The physical interpretation is important since edge detection algorithms alone do not specify any physical measure, or physical definition, of the leading edge of the spreading population. Our modeling indicates that variations in the image threshold parameter correspond to a consistent variation in the local cell density. This means that varying the threshold parameter is equivalent to varying the location of the leading edge in the range of approximately 1-5% of the maximum cell density.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Maternal thyroid dysfunction affects placental profile of inflammatory mediators and the intrauterine trophoblast migration kinetics.

    PubMed

    Silva, Juneo Freitas; Ocarino, Natália Melo; Serakides, Rogéria

    2014-06-01

    The objective of the present study was to evaluate the gene and immunohistochemical expression of inflammatory mediators involved in the immune activity and the intrauterine trophoblast migration of the placentas in hypothyroid and L-thyroxine (L-T4)-treated rats. A total of 144 adult female rats were divided equally into hypothyroid, l-T4-treated, and euthyroid (control) groups. Hypothyroidism was induced by daily administration of propylthiouracil. Rats were killed at 0, 10, 14, 15, 16, 17, 18, and 19 days of gestation. We evaluated the depth of interstitial and endovascular intrauterine trophoblast invasion and the immunohistochemical expression of interferon γ (INFy), migration inhibitory factor (MIF), and inducible nitric oxide synthase (NOS2 (iNOS)). The gene expression of Toll-like receptor 2 (Tlr2) and Tlr4, Infy, Mif, tumor necrosis factor (Tnf (Tnfα)), Il10, Nos2, matrix metalloproteinase 2 (Mmp2) and Mmp9, and placental leptin was also measured in placental disks by real-time RT-PCR. The data were analyzed using an Student-Newman-Keuls (SNK) test. Hypothyroidism reduced the endovascular and interstitial trophoblast migration, and the expression of TLR4, INFy, MIF, interleukin 10 (IL10), NOS2, MMP2 and MMP9, and placental leptin, while increased the expression of TLR2 (P<0.05). T4-treated rats not only increased the expression of IL10 and NOS2 but also reduced the expression of TNF and MIF at 10 days of gestation (P<0.05). However, at 19 days of gestation, expression of INFy and MIF was increased in T4-treated group (P<0.05). Excess of T4 also increased the gene expression of Mmp2 at 10 days of gestation (P<0.05), but reduced the endovascular trophoblast migration at 18 days of gestation (P<0.05). Hypothyroidism and excess of T4 differentially affect the immune profile and the intrauterine trophoblast migration of the placenta, and these effects are dependent on the gestational period.

  10. Comparative mechanisms of cancer cell migration through 3D matrix and physiological microtracks.

    PubMed

    Carey, Shawn P; Rahman, Aniqua; Kraning-Rush, Casey M; Romero, Bethsabe; Somasegar, Sahana; Torre, Olivia M; Williams, Rebecca M; Reinhart-King, Cynthia A

    2015-03-15

    Tumor cell invasion through the stromal extracellular matrix (ECM) is a key feature of cancer metastasis, and understanding the cellular mechanisms of invasive migration is critical to the development of effective diagnostic and therapeutic strategies. Since cancer cell migration is highly adaptable to physiochemical properties of the ECM, it is critical to define these migration mechanisms in a context-specific manner. Although extensive work has characterized cancer cell migration in two- and three-dimensional (3D) matrix environments, the migration program employed by cells to move through native and cell-derived microtracks within the stromal ECM remains unclear. We previously reported the development of an in vitro model of patterned type I collagen microtracks that enable matrix metalloproteinase-independent microtrack migration. Here we show that collagen microtracks closely resemble channel-like gaps in native mammary stroma ECM and examine the extracellular and intracellular mechanisms underlying microtrack migration. Cell-matrix mechanocoupling, while critical for migration through 3D matrix, is not necessary for microtrack migration. Instead, cytoskeletal dynamics, including actin polymerization, cortical tension, and microtubule turnover, enable persistent, polarized migration through physiological microtracks. These results indicate that tumor cells employ context-specific mechanisms to migrate and suggest that selective targeting of cytoskeletal dynamics, but not adhesion, proteolysis, or cell traction forces, may effectively inhibit cancer cell migration through preformed matrix microtracks within the tumor stroma.

  11. Lamin-B1 contributes to the proper timing of epicardial cell migration and function during embryonic heart development

    PubMed Central

    Tran, Joseph R.; Zheng, Xiaobin; Zheng, Yixian

    2016-01-01

    Lamin proteins form a meshwork beneath the nuclear envelope and contribute to many different cellular processes. Mutations in lamins cause defective organogenesis in mouse models and human diseases that affect adipose tissue, brain, skeletal muscle, and the heart. In vitro cell culture studies have shown that lamins help maintain nuclear shape and facilitate cell migration. However, whether these defects contribute to improper tissue building in vivo requires further clarification. By studying the heart epicardium during embryogenesis, we show that Lb1-null epicardial cells exhibit in vivo and in vitro migratory delay. Transcriptome analyses of these cells suggest that Lb1 influences the expression of cell adhesion genes, which could affect cell migration during epicardium development. These epicardial defects are consistent with incomplete development of both vascular smooth muscle and compact myocardium at later developmental stages in Lb1-null embryos. Further, we found that Lb1-null epicardial cells have a delayed nuclear morphology change in vivo, suggesting that Lb1 facilitates morphological changes associated with migration. These findings suggest that Lb1 contributes to nuclear shape maintenance and migration of epicardial cells and highlights the use of these cells for in vitro and in vivo study of these classic cell biological phenomena. PMID:27798236

  12. Combinative in vitro studies and computational model to predict 3D cell migration response to drug insult.

    PubMed

    Maffei, Joseph S; Srivastava, Jaya; Fallica, Brian; Zaman, Muhammad H

    2014-10-01

    The development of drugs to counter diseases related to cell migration has resulted in a multi-billion dollar endeavor. Unfortunately, few drugs have emerged from this effort highlighting the need for new methods to enhance assays to study, analyze and control cell migration. In response to this complex process, computational models have emerged as potent tools to describe migration providing a high throughput and low cost method. However, most models are unable to predict migration response to drug with direct application to in vitro experiments. In addition to this, no model to date has attempted to describe migration in response to drugs while incorporating simultaneously protein signaling, proteolytic activity, and 3D culture. In this paper, we describe an integrated computational approach, in conjunction with in vitro observations, to serve as a platform to accurately predict migration in 3D matrices incorporating the function of matrix metalloproteinases (MMPs) and their interaction with the Extracellular signal-related kinase (ERK) signaling pathway. Our results provide biological insight into how matrix density, MMP activity, integrin adhesions, and p-ERK expression all affect speed and persistence in 3D. Predictions from the model provide insight toward improving drug combinations to more effectively reduce both speed and persistence during migration and the role of integrin adhesions in motility. In this way our integrated platform provides future potential to streamline and improve throughput toward the testing and development of migration targeting drugs with tangible application to current in vitro assays.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Cell migration under ultrasound irradiations in micrometer scale

    NASA Astrophysics Data System (ADS)

    Murakami, Shinya; Otsuka, Yo; Oshima, Yusuke; Hikita, Atsuhiko; Mitsui, Toshiyuki

    2013-03-01

    Cell movements, migration play an important role in many physiological processes including cell proliferation and differentiation. C2C12, a line of mouse myoblasts is known to differentiate into osteoblast under appropriate conditions. Therefore, C2C12 cells can be chosen for the differentiation studies. However, the movement of the C2C12's has not been fully investigated although the movements may provide a better understanding of the healing processes of bone repair, regeneration and differentiation. In addition, low intensity ultrasound has been thought and used to promote bone fracture healing although the microscopic mechanism of this healing is not well understood. As a first step, we have investigated single cell migration of C2C12 under optical microscopy with and without ultrasound irradiations. The ultrasound is irradiated from an apex of a sharp needle. The frequency is 1.5 MHz and the power intensity is near 24 mW/cm2. These values were similar to the ultrasound treatment values. In this conference, we will show the influence of the ultrasound irradiation on the cell movement by plotting the mean squared displacement and the velocity autocorrelation function as a function of time.

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

    PubMed

    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

  20. 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

  1. Valproate, thalidomide and ethyl alcohol alter the migration of HTR-8/SVneo cells

    PubMed Central

    Rout, Ujjwal K

    2006-01-01

    Background Valproate, thalidomide and alcohol (ethanol) exposure during the first trimester of pregnancy is known to cause several developmental disorders. All these teratogens are known to pass the placental barrier and interfere directly with the normal development of the fetus. However, these teratogens also alter the formation and function of the placenta itself which may in turn affect the proper nourishment and development of the fetus. Optimum development of the placenta requires adequate invasion of trophoblast into the maternal uterine tissues. Changes in the migratory behavior of trophoblast by maternal exposure to these teratogens during placentogenesis may therefore alter the structure and function of the placenta. Methods In the present study, the effects of sodium valproate, thalidomide and alcohol on the migration of human first trimester trophoblast cell line (HTR-8/SVneo) were examined in vitro. Cells were cultured in the wells of 48-well culture plates as mono or multilayers. Circular patches of cells were removed from the center of the wells by suction, and the migration of cells into the wound was studied using microscopy. Effects of low and high concentrations of valproate, thalidomide and alcohol were examined on the healing of wounds and on the migration rate of cells by determining the wound areas at 0, 3, 6, 12, 24 and 48 h. Effects of drugs and alcohol on the proliferation and the expression levels of integrin subunits beta1 and alpha5 in cells were examined. Results The migration rates of trophoblast differed between wounds created in mono and multilayers of cells. Exposure to teratogens altered the migration of trophoblast into mono and multilayer wounds. The effects of valproate, thalidomide and alcohol on the proliferation of cells during the rapid migratory phase were mild. Drug exposure caused significant changes in the expression levels of beta1 and alpha5 integrin subunits. Conclusion Results suggest that exposure to valproate

  2. Cell Image Velocimetry (CIV): boosting the automated quantification of cell migration in wound healing assays.

    PubMed

    Milde, Florian; Franco, Davide; Ferrari, Aldo; Kurtcuoglu, Vartan; Poulikakos, Dimos; Koumoutsakos, Petros

    2012-11-01

    Cell migration is commonly quantified by tracking the speed of the cell layer interface in wound healing assays. This quantification is often hampered by low signal to noise ratio, in particular when complex substrates are employed to emulate in vivo cell migration in geometrically complex environments. Moreover, information about the cell motion, readily available inside the migrating cell layers, is not usually harvested. We introduce Cell Image Velocimetry (CIV), a combination of cell layer segmentation and image velocimetry algorithms, to drastically enhance the quantification of cell migration by wound healing assays. The resulting software analyses the speed of the interface as well as the detailed velocity field inside the cell layers in an automated fashion. CIV is shown to be highly robust for images with low signal to noise ratio, low contrast and frame shifting and it is portable across various experimental settings. The modular design and parametrization of CIV is not restricted to wound healing assays and allows for the exploration and quantification of flow phenomena in any optical microscopy dataset. Here, we demonstrate the capabilities of CIV in wound healing assays over topographically engineered surfaces and quantify the relative merits of differently aligned gratings on cell migration.

  3. 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.

  4. A porous 3D cell culture micro device for cell migration study.

    PubMed

    Ma, Liang; Zhou, Changchun; Lin, Biaoyang; Li, Wei

    2010-08-01

    Cell migration under chemoattractant is an important biological step in cancer metastasis that causes the spread of malignant tumor cells. Porous polymeric materials are widely used to mimic the extracellular matrix (ECM) environment for applications such as three dimensional (3D) cell culturing and tissue engineering. In this paper we report a novel 3D cell culture device based on porous polymeric material to study cancer migration. We fabricated a porous channel on a polymeric chip using a selective ultrasonic foaming method. We demonstrate that a chemical concentration gradient could be established through the porous channel due to the slow diffusion process. We show that significant cell migration could be observed through the porous channel within 1-2 weeks of cell culturing when metastatic M4A4-GFP breast cancer cells were induced by 20% fetal bovine serum (FBS).We also developed a mathematical model to evaluate the diffusivity and concentration gradient through the fabricated porous structure.

  5. 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.

  6. Snail promotes cell migration through PI3K/AKT-dependent Rac1 activation as well as PI3K/AKT-independent pathways during prostate cancer progression

    PubMed Central

    Henderson, Veronica; Smith, Basil; Burton, Liza J; Randle, Diandra; Morris, Marisha; Odero-Marah, Valerie A

    2015-01-01

    Snail, a zinc-finger transcription factor, induces epithelial-mesenchymal transition (EMT), which is associated with increased cell migration and metastasis in cancer cells. Rac1 is a small G-protein which upon activation results in formation of lamellipodia, the first protrusions formed by migrating cells. We have previously shown that Snail promotes cell migration through down-regulation of maspin tumor suppressor. We hypothesized that Snail's regulation of cell migration may also involve Rac1 signaling regulated by PI3K/AKT and/or MAPK pathways. We found that Snail overexpression in LNCaP and 22Rv1 prostate cancer cells increased Rac1 activity associated with increased cell migration, and the Rac1 inhibitor, NSC23766, could inhibit Snail-mediated cell migration. Conversely, Snail downregulation using shRNA in the aggressive C4–2 prostate cancer cells decreased Rac1 activity and cell migration. Moreover, Snail overexpression increased ERK and PI3K/AKT activity in 22Rv1 prostate cancer cells. Treatment of Snail-overexpressing 22Rv1 cells with LY294002, PI3K/AKT inhibitor or U0126, MEK inhibitor, decreased cell migration significantly, but only LY294002 significantly reduced Rac1 activity, suggesting that Snail promotes Rac1 activation via the PI3K/AKT pathway. Furthermore, 22Rv1 cells overexpressing Snail displayed decreased maspin levels, while inhibition of maspin expression in 22Rv1 cells with siRNA, led to increased PI3K/AKT, Rac1 activity and cell migration, without affecting ERK activity, suggesting that maspin is upstream of PI3K/AKT. Overall, we have dissected signaling pathways by which Snail may promote cell migration through MAPK signaling or alternatively through PI3K/AKT-Rac1 signaling that involves Snail inhibition of maspin tumor suppressor. This may contribute to prostate cancer progression. PMID:26207671

  7. 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.

  8. 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.

  9. Siah1/SIP regulates p27(kip1) stability and cell migration under metabolic stress.

    PubMed

    Nagano, Yoshito; Fukushima, Toru; Okemoto, Kazuo; Tanaka, Keiichiro; Bowtell, David D L; Ronai, Ze'ev; Reed, John C; Matsuzawa, Shu-ichi

    2011-08-01

    p27(kip1) has been implicated in cell cycle regulation, functioning as an inhibitor of cyclin-dependent kinase activity. In addition, p27 was also shown to affect cell migration, with accumulation of cytoplasmic p27 associated with tumor invasiveness. However, the mechanism underlying p27 regulation as a cytoplasmic protein is poorly understood. Here we show that glucose starvation induces proteasome-dependent degradation of cytoplasmic p27, accompanied by a decrease in cell motility. We also show that the glucose limitation-induced p27 degradation is regulated through an ubiquitin E3 ligase complex involving Siah1 and SIP/CacyBP. SIP (-/-) embryonic fibroblasts have increased levels of cytosolic p27 and exhibit increased cell motility compared to wild-type cells. These observations suggest that the Siah1/SIP E3 ligase complex regulates cell motility through degradation of p27.

  10. Towing of sensory axons by their migrating target cells in vivo.

    PubMed

    Gilmour, Darren; Knaut, Holger; Maischein, Hans-Martin; Nüsslein-Volhard, Christiane

    2004-05-01

    Many pathfinding axons must locate target fields that are themselves positioned by active migration. A hypothetical method for ensuring that these migrations are coordinated is towing, whereby the extension of axons is entirely dependent on the migration of their target cells. Here we combine genetics and time-lapse imaging in the zebrafish to show that towing by migrating cells is a bona fide mechanism for guiding pathfinding axons in vivo.

  11. Lymph node topology dictates T cell migration behavior

    PubMed Central

    Beltman, Joost B.; Marée, Athanasius F.M.; Lynch, Jennifer N.; Miller, Mark J.; de Boer, Rob J.

    2007-01-01

    Adaptive immunity is initiated by T cell recognition of foreign peptides presented on dendritic cells (DCs) by major histocompatibility molecules. These interactions take place in secondary lymphoid tissues, such as lymph nodes (LNs) and spleen, and hence the anatomical structure of these tissues plays a crucial role in the development of immune responses. Two-photon microscopy (2PM) imaging in LNs suggests that T cells walk in a consistent direction for several minutes, pause briefly with a regular period, and then take off in a new, random direction. Here, we construct a spatially explicit model of T cell and DC migration in LNs and show that all dynamical properties of T cells could be a consequence of the densely packed LN environment. By means of 2PM experiments, we confirm that the large velocity fluctuations of T cells are indeed environmentally determined rather than resulting from an intrinsic motility program. Our simulations further predict that T cells self-organize into microscopically small, highly dynamic streams. We present experimental evidence for the presence of such turbulent streams in LNs. Finally, the model allows us to estimate the scanning rates of DCs (2,000 different T cells per hour) and T cells (100 different DCs per hour). PMID:17389236

  12. Lymph node topology dictates T cell migration behavior.

    PubMed

    Beltman, Joost B; Marée, Athanasius F M; Lynch, Jennifer N; Miller, Mark J; de Boer, Rob J

    2007-04-16

    Adaptive immunity is initiated by T cell recognition of foreign peptides presented on dendritic cells (DCs) by major histocompatibility molecules. These interactions take place in secondary lymphoid tissues, such as lymph nodes (LNs) and spleen, and hence the anatomical structure of these tissues plays a crucial role in the development of immune responses. Two-photon microscopy (2PM) imaging in LNs suggests that T cells walk in a consistent direction for several minutes, pause briefly with a regular period, and then take off in a new, random direction. Here, we construct a spatially explicit model of T cell and DC migration in LNs and show that all dynamical properties of T cells could be a consequence of the densely packed LN environment. By means of 2PM experiments, we confirm that the large velocity fluctuations of T cells are indeed environmentally determined rather than resulting from an intrinsic motility program. Our simulations further predict that T cells self-organize into microscopically small, highly dynamic streams. We present experimental evidence for the presence of such turbulent streams in LNs. Finally, the model allows us to estimate the scanning rates of DCs (2,000 different T cells per hour) and T cells (100 different DCs per hour).

  13. Hypoxia Increases Breast Cancer Cell-Induced Lymphatic Endothelial Cell Migration12

    PubMed Central

    Mikhaylova, Maria; Mori, Noriko; Wildes, Flonné B; Walczak, Piotr; Gimi, Barjor; Bhujwalla, Zaver M

    2008-01-01

    Because tumors are characterized by hypoxic environments, we used a novel in vitro noninvasive magnetic resonance imaging assay to examine the influence of invasive MDA-MB-231 breast cancer cells on the invasion and migration of human dermal lymphatic microvascular endothelial cells (HMVEC-dLy) under normoxic and hypoxic conditions. Nonmalignant immortalized MCF-12A human mammary epithelial cells instead of cancer cells or chambers with HMVEC-dLy alone were used as controls for comparison. HMVEC-dLy cells were labeled with a T2 contrast agent (Feridex), and their invasion and migration through extracellular matrix under normoxic and hypoxic conditions were monitored using magnetic resonance imaging. A significant increase in the invasion and migration of HMVEC-dLy cells was detected in the presence of cancer cells, which further increased significantly under hypoxic conditions. HMVEC-dLy cells formed interconnecting strands extending toward the cancer cells under normoxic but not under hypoxic conditions. Following reoxygenation, these interconnecting strands, extending from HMVEC-dLy cells toward the cancer cells, were observed. These data demonstrate the importance of hypoxia in lymphatic endothelial cell invasion and migration through extracellular matrix in the presence of cancer cells. PMID:18392137

  14. 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.

  15. Slit-2 facilitates interaction of P-cadherin with Robo-3 and inhibits cell migration in an oral squamous cell carcinoma cell line.

    PubMed

    Bauer, Karin; Dowejko, Albert; Bosserhoff, A-K; Reichert, T E; Bauer, Richard

    2011-06-01

    Slits are a group of secreted glycoproteins that act as molecular guidance cues in cellular migration. Recently, several studies demonstrated that Slit-2 can operate as candidate tumour suppressor protein in various tissues. In this study, we show Slit-2 expression in basal cell layers of normal oral mucosa colocalized with P-cadherin expression. In contrast, there is a loss of Slit-2 and P-cadherin expression in mucosa of oral squamous cell carcinoma (OSCC). Our in vitro investigations reveal a correlation of P-cadherin and Slit-2 expression: OSCC cells with induced P-cadherin expression (PCI52_PC) display an increased Slit-2 expression. However, abrogating P-cadherin function with a function-blocking antibody decreases Slit-2 secretion confirming a direct link between P-cadherin and Slit-2. Moreover, experiments with OSCC cells show that Slit-2 interferes with a Wnt related signalling pathway, which in turn affects Slit-2 expression in a feedback loop. Functionally, transwell migration assays demonstrate a Slit-2 dose-dependent decrease of PCI52_PC cell migration. However, there is no influence on migration in mock control cells. Responsible for this migration block might be an interaction of P-cadherin with Roundabout (Robo)-3, a high affinity receptor of Slit-2. Indeed, proximity ligation assays exhibit P-cadherin/Robo-3 interactions on PCI52_PC cells. Additionally, we detect a modulation of this interaction by addition of recombinant Slit-2. Down-regulation of Robo-3 expression via small interfering RNA neutralizes Slit-2 induced migration block in PCI52_PC cells. In summary, our experiments show antitumorigenic effects of Slit-2 on P-cadherin expressing OSCC cells supposedly via modulation of Robo-3 interaction.

  16. 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.

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

    PubMed Central

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

    2015-01-01

    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), 40 mM 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. PMID:26549367

  18. Insulin-like growth factor I induces migration and invasion of human multiple myeloma cells.

    PubMed

    Qiang, Ya-Wei; Yao, Lei; Tosato, Giovanna; Rudikoff, Stuart

    2004-01-01

    Multiple myeloma (MM) is an incurable form of cancer characterized by accumulation of malignant plasma cells in the bone marrow. During the course of this disease, tumor cells cross endothelial barriers and home to the bone marrow. In latter stages, myeloma cells extravasate through blood vessels and may seed a variety of organs. Insulin-like growth factor I (IGF-I) is one of several growth factors shown to promote the growth of MM cells. In the current study, we have assessed the ability of IGF-I to serve additionally as a chemotactic factor affecting the mobility and invasive properties of these cells. Results indicate that IGF-I promotes transmigration through vascular endothelial cells and bone marrow stromal cell lines. Analysis of endogenous signaling pathways revealed that protein kinase D/protein kinase Cmicro (PKD/PKCmicro) and RhoA were both activated in a phosphatidylinositol 3-kinase (PI-3K)-dependent manner. Inhibition of PI-3K, PKCs, or Rho-associated kinase by pharmacologic inhibitors abrogated migration, whereas mitogen-activated protein kinase (MAPK), Akt, and p70S6 kinase inhibitors had no effect. These results suggest that IGF-I promotes myeloma cell migration by activation of PI-3K/PKCmicro and PI-3K/RhoA pathways independent of Akt. The identification of IGF-I as both a proliferative and migratory factor provides a rational basis for the development of targeted therapeutic strategies directed at IGF-I in the treatment of MM.

  19. 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.

  20. A high-throughput cell migration assay using scratch wound healing, a comparison of image-based readout methods

    PubMed Central

    Yarrow, Justin C; Perlman, Zachary E; Westwood, Nicholas J; Mitchison, Timothy J

    2004-01-01

    Background Cell migration is a complex phenomenon that requires the coordination of numerous cellular processes. Investigation of cell migration and its underlying biology is of interest to basic scientists and those in search of therapeutics. Current migration assays for screening small molecules, siRNAs, or other perturbations are difficult to perform in parallel at the scale required to screen large libraries. Results We have adapted the commonly used scratch wound healing assay of tissue-culture cell monolayers to a 384 well plate format. By mechanically scratching the cell substrate with a pin array, we are able to create characteristically sized wounds in all wells of a 384 well plate. Imaging of the healing wounds with an automated fluorescence microscope allows us to distinguish perturbations that affect cell migration, morphology, and division. Readout requires ~1 hr per plate but is high in information content i.e. high content. We compare readouts using different imaging technologies, automated microscopy, scanners and a fluorescence macroscope, and evaluate the trade-off between information content and data acquisition rate. Conclusions The adaptation of a wound healing assay to a 384 well format facilitates the study of aspects of cell migration, tissue reorganization, cell division, and other processes that underlie wound healing. This assay allows greater than 10,000 perturbations to be screened per day with a quantitative, high-content readout, and can also be used to characterize small numbers of perturbations in detail. PMID:15357872

  1. RNase L Suppresses Androgen Receptor Signaling, Cell Migration and Matrix Metalloproteinase Activity in Prostate Cancer Cells.

    PubMed

    Dayal, Shubham; Zhou, Jun; Manivannan, Praveen; Siddiqui, Mohammad Adnan; Ahmad, Omaima Farid; Clark, Matthew; Awadia, Sahezeel; Garcia-Mata, Rafael; Shemshedini, Lirim; Malathi, Krishnamurthy

    2017-03-01

    The interferon antiviral pathways and prostate cancer genetics converge on a regulated endoribonuclease, RNase L. Positional cloning and linkage studies mapped Hereditary Prostate Cancer 1 (HPC1) to RNASEL. To date, there is no correlation of viral infections with prostate cancer, suggesting that RNase L may play additional roles in tumor suppression. Here, we demonstrate a role of RNase L as a suppressor of androgen receptor (AR) signaling, cell migration and matrix metalloproteinase activity. Using RNase L mutants, we show that its nucleolytic activity is dispensable for both AR signaling and migration. The most prevalent HPC1-associated mutations in RNase L, R462Q and E265X, enhance AR signaling and cell migration. RNase L negatively regulates cell migration and attachment on various extracellular matrices. We demonstrate that RNase L knockdown cells promote increased cell surface expression of integrin β1 which activates Focal Adhesion Kinase-Sarcoma (FAK-Src) pathway and Ras-related C3 botulinum toxin substrate 1-guanosine triphosphatase (Rac1-GTPase) activity to increase cell migration. Activity of matrix metalloproteinase (MMP)-2 and -9 is significantly increased in cells where RNase L levels are ablated. We show that mutations in RNase L found in HPC patients may promote prostate cancer by increasing expression of AR-responsive genes and cell motility and identify novel roles of RNase L as a prostate cancer susceptibility gene.

  2. RNase L Suppresses Androgen Receptor Signaling, Cell Migration and Matrix Metalloproteinase Activity in Prostate Cancer Cells

    PubMed Central

    Dayal, Shubham; Zhou, Jun; Manivannan, Praveen; Siddiqui, Mohammad Adnan; Ahmad, Omaima Farid; Clark, Matthew; Awadia, Sahezeel; Garcia-Mata, Rafael; Shemshedini, Lirim; Malathi, Krishnamurthy

    2017-01-01

    The interferon antiviral pathways and prostate cancer genetics converge on a regulated endoribonuclease, RNase L. Positional cloning and linkage studies mapped Hereditary Prostate Cancer 1 (HPC1) to RNASEL. To date, there is no correlation of viral infections with prostate cancer, suggesting that RNase L may play additional roles in tumor suppression. Here, we demonstrate a role of RNase L as a suppressor of androgen receptor (AR) signaling, cell migration and matrix metalloproteinase activity. Using RNase L mutants, we show that its nucleolytic activity is dispensable for both AR signaling and migration. The most prevalent HPC1-associated mutations in RNase L, R462Q and E265X, enhance AR signaling and cell migration. RNase L negatively regulates cell migration and attachment on various extracellular matrices. We demonstrate that RNase L knockdown cells promote increased cell surface expression of integrin β1 which activates Focal Adhesion Kinase-Sarcoma (FAK-Src) pathway and Ras-related C3 botulinum toxin substrate 1-guanosine triphosphatase (Rac1-GTPase) activity to increase cell migration. Activity of matrix metalloproteinase (MMP)-2 and -9 is significantly increased in cells where RNase L levels are ablated. We show that mutations in RNase L found in HPC patients may promote prostate cancer by increasing expression of AR-responsive genes and cell motility and identify novel roles of RNase L as a prostate cancer susceptibility gene. PMID:28257035

  3. 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.

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

    PubMed Central

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

    2015-01-01

    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 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 modeling to show that leader cell identity is dynamically regulated by Dll4 signaling 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 signaling to dynamically regulate the density of leader cells during collective cell migration. PMID:25766473

  5. SIRT1 is highly expressed in brain metastasis tissues of non-small cell lung cancer (NSCLC) and in positive regulation of NSCLC cell migration.

    PubMed

    Han, Lin; Liang, Xiao-Hua; Chen, Li-Xin; Bao, Shi-Min; Yan, Zhi-Qiang

    2013-01-01

    Brain metastases are a frequent and ongoing major complication of non-small cell lung cancer (NSCLC). To deepen our understanding to the underlying mechanisms by which NSCLC cells metastasize to brain and hence to improve the therapy, a high throughput RNAi screening with shRNA library of 153 epigenetic genes was subjected to A549, a NSCLC cell line with high migration ability, to examine the effects of these genes on cell migration by wound-healing assay. The screening results showed that knockdown of 2 genes (KDM5B and SIRT1) dramatically and specifically inhibits A549 migration but not affects the proliferation, which was subsequently confirmed through transwell migration assay. Furthermore, SIRT1 is found to be highly expressed in brain metastasis tissues of NSCLC, compared to the NSCLC tissues, suggesting that SIRT1 may play roles in brain metastasis of NSCLC. The relationship between SIRT1 expression and cell migration ability was further investigated in three NSCLC cell lines and the result indicated that SIRT1 expression is tightly correlated with cell migration ability. Collectively, our work provides potential biomarker and therapeutic target for brain metastasis of NSCLC.

  6. Analysis of CCR7 mediated T cell transfectant migration using a microfluidic gradient generator.

    PubMed

    Wu, Xun; Wu, Jiandong; Li, Hongzhao; Legler, Daniel F; Marshall, Aaron J; Lin, Francis

    2015-04-01

    T lymphocyte migration is crucial for adaptive immunity. Manipulation of signaling molecules controlling cell migration combined with in-vitro cell migration analysis provides a powerful research approach. Microfluidic devices, which can precisely configure chemoattractant gradients and allow quantitative single cell analysis, have been increasingly applied to cell migration and chemotaxis studies. However, there are a very limited number of published studies involving microfluidic migration analysis of genetically manipulated immune cells. In this study, we describe a simple microfluidic method for quantitative analysis of T cells expressing transfected chemokine receptors and other cell migration signaling probes. Using this method, we demonstrated chemotaxis of Jurkat transfectants expressing wild-type or C-terminus mutated CCR7 within a gradient of chemokine CCL19, and characterized the difference in transfectant migration mediated by wild-type and mutant CCR7. The EGFP-tagged CCR7 allows identification of CCR7-expressing transfectants in cell migration analysis and microscopy assessment of CCR7 dynamics. Collectively, our study demonstrated the effective use of the microfluidic method for studying CCR7 mediated T cell transfectant migration. We envision this developed method will provide a useful platform to functionally test various signaling mechanisms at the cell migration level.

  7. Cellular automata model for human articular chondrocytes migration, proliferation and cell death: An in vitro validation.

    PubMed

    Vaca-González, J J; Gutiérrez, M L; Guevara, J M; Garzón-Alvarado, D A

    2016-01-07

    Articular cartilage is characterized by low cell density of only one cell type, chondrocytes, and has limited self-healing properties. When articular cartilage is affected by traumatic injuries, a therapeutic strategy such as autologous chondrocyte implantation is usually proposed for its treatment. This approach requires in vitro chondrocyte expansion to yield high cell number for cell transplantation. To improve the efficiency of this procedure, it is necessary to assess cell dynamics such as migration, proliferation and cell death during culture. Computational models such as cellular automata can be used to simulate cell dynamics in order to enhance the result of cell culture procedures. This methodology has been implemented for several cell types; however, an experimental validation is required for each one. For this reason, in this research a cellular automata model, based on random-walk theory, was devised in order to predict articular chondrocyte behavior in monolayer culture during cell expansion. Results demonstrated that the cellular automata model corresponded to cell dynamics and computed-accurate quantitative results. Moreover, it was possible to observe that cell dynamics depend on weighted probabilities derived from experimental data and cell behavior varies according to the cell culture period. Thus, depending on whether cells were just seeded or proliferated exponentially, culture time probabilities differed in percentages in the CA model. Furthermore, in the experimental assessment a decreased chondrocyte proliferation was observed along with increased passage number. This approach is expected to having other uses as in enhancing articular cartilage therapies based on tissue engineering and regenerative medicine.

  8. Filopodia in cell adhesion, 3D migration and cancer cell invasion.

    PubMed

    Jacquemet, Guillaume; Hamidi, Hellyeh; Ivaska, Johanna

    2015-10-01

    This review discusses recent advances in our understanding of the role filopodia and filopodia-like structures in cell adhesion and three dimensional (3D) cell migration both in vitro and in vivo. In particular, we focus on recent advances demonstrating that filopodia are involved in substrate tethering and environment sensing in vivo. We further discuss the emerging role of filopodia and filopodial proteins in tumor dissemination as mounting in vitro, in vivo and clinical evidence suggest that filopodia drive cancer cell invasion and highlight filopodia proteins as attractive therapeutic targets. Finally, we outline outstanding questions that remain to be addressed to elucidate the role of filopodia during 3D cell migration.

  9. The ciliary GTPase Arl13b regulates cell migration and cell cycle progression

    PubMed Central

    Pruski, Michal; Rajnicek, Ann; Yang, Zhifu; Clancy, Hannah; Ding, Yu-Qiang; McCaig, Colin D.; Lang, Bing

    2016-01-01

    ABSTRACT The GTPase ARL13B is localized to primary cilia; small cellular protrusions that act as antennae. Its defective ARL13B hennin (HNN) variant is linked causally with Joubert Syndrome, a developmental ciliopathy attributed to poor sensing of extracellular chemical gradients. We tested the hypothesis that impaired detection of extracellular voltage gradients also contributes to the HNN phenotype. In vitro, extracellular electric fields stimulated migration of wild type (WT) and HNN fibroblasts toward the cathode but the field only increased the migration speed of WT cells. Cilia on WT cells did not align to the field vector. HNN cells divided more slowly than WT cells, arresting at the G2/M phase. Mechanistically, HNN cells had reduced phospho-ERK1/2 signaling and elevated levels of Suppressor of Fused protein. These suggest that cells may not be able to read extracellular chemical cues appropriately, resulting in deficits in cell migration and proliferation. Finally, an increase in tubulin stabilization (more detyrosinated tubulin) confirmed the general stagnation of HNN cells, which may further contribute to slower migration and cell cycle progression. We conclude that Arl13b dysfunction resulted in HNN cell stagnation due to poor growth factor signaling and impaired detection of extracellular electrical gradients, and that the role of Arl13b in cell proliferation may be understated. PMID:26963749

  10. Effects of BKCa and Kir2.1 Channels on Cell Cycling Progression and Migration in Human Cardiac c-kit+ Progenitor Cells.

    PubMed

    Zhang, Ying-Ying; Li, Gang; Che, Hui; Sun, Hai-Ying; Xiao, Guo-Sheng; Wang, Yan; Li, Gui-Rong

    2015-01-01

    Our previous study demonstrated that a large-conductance Ca2+-activated K+ current (BKCa), a voltage-gated TTX-sensitive sodium current (INa.TTX), and an inward rectifier K+ current (IKir) were heterogeneously present in most of human cardiac c-kit+ progenitor cells. The present study was designed to investigate the effects of these ion channels on cell cycling progression and migration of human cardiac c-kit+ progenitor cells with approaches of cell proliferation and mobility assays, siRNA, RT-PCR, Western blots, flow cytometry analysis, etc. It was found that inhibition of BKCa with paxilline, but not INa.TTX with tetrodotoxin, decreased both cell proliferation and migration. Inhibition of IKir with Ba2+ had no effect on cell proliferation, while enhanced cell mobility. Silencing KCa.1.1 reduced cell proliferation by accumulating the cells at G0/G1 phase and decreased cell mobility. Interestingly, silencing Kir2.1 increased the cell migration without affecting cell cycling progression. These results demonstrate the novel information that blockade or silence of BKCa channels, but not INa.TTX channels, decreases cell cycling progression and mobility, whereas inhibition of Kir2.1 channels increases cell mobility without affecting cell cycling progression in human cardiac c-kit+ progenitor cells.

  11. Effects of BKCa and Kir2.1 Channels on Cell Cycling Progression and Migration in Human Cardiac c-kit+ Progenitor Cells

    PubMed Central

    Zhang, Ying-Ying; Li, Gang; Che, Hui; Sun, Hai-Ying; Xiao, Guo-Sheng; Wang, Yan; Li, Gui-Rong

    2015-01-01

    Our previous study demonstrated that a large-conductance Ca2+-activated K+ current (BKCa), a voltage-gated TTX-sensitive sodium current (INa.TTX), and an inward rectifier K+ current (IKir) were heterogeneously present in most of human cardiac c-kit+ progenitor cells. The present study was designed to investigate the effects of these ion channels on cell cycling progression and migration of human cardiac c-kit+ progenitor cells with approaches of cell proliferation and mobility assays, siRNA, RT-PCR, Western blots, flow cytometry analysis, etc. It was found that inhibition of BKCa with paxilline, but not INa.TTX with tetrodotoxin, decreased both cell proliferation and migration. Inhibition of IKir with Ba2+ had no effect on cell proliferation, while enhanced cell mobility. Silencing KCa.1.1 reduced cell proliferation by accumulating the cells at G0/G1 phase and decreased cell mobility. Interestingly, silencing Kir2.1 increased the cell migration without affecting cell cycling progression. These results demonstrate the novel information that blockade or silence of BKCa channels, but not INa.TTX channels, decreases cell cycling progression and mobility, whereas inhibition of Kir2.1 channels increases cell mobility without affecting cell cycling progression in human cardiac c-kit+ progenitor cells. PMID:26390131

  12. Beta Adrenergic Receptor Stimulation Suppresses Cell Migration in Association with Cell Cycle Transition in Osteoblasts-Live Imaging Analyses Based on FUCCI System.

    PubMed

    Katsumura, Sakie; Ezura, Yoichi; Izu, Yayoi; Shirakawa, Jumpei; Miyawaki, Atsushi; Harada, Kiyoshi; Noda, Masaki

    2016-02-01

    Osteoporosis affects over 20 million patients in the United States. Among those, disuse osteoporosis is serious as it is induced by bed-ridden conditions in patients suffering from aging-associated diseases including cardiovascular, neurological, and malignant neoplastic diseases. Although the phenomenon that loss of mechanical stress such as bed-ridden condition reduces bone mass is clear, molecular bases for the disuse osteoporosis are still incompletely understood. In disuse osteoporosis model, bone loss is interfered by inhibitors of sympathetic tone and adrenergic receptors that suppress bone formation. However, how beta adrenergic stimulation affects osteoblastic migration and associated proliferation is not known. Here we introduced a live imaging system, fluorescent ubiquitination-based cell cycle indicator (FUCCI), in osteoblast biology and examined isoproterenol regulation of cell cycle transition and cell migration in osteoblasts. Isoproterenol treatment suppresses the levels of first entry peak of quiescent osteoblastic cells into cell cycle phase by shifting from G1 /G0 to S/G2 /M and also suppresses the levels of second major peak population that enters into S/G2 /M. The isoproterenol regulation of osteoblastic cell cycle transition is associated with isoproterenol suppression on the velocity of migration. This isoproterenol regulation of migration velocity is cell cycle phase specific as it suppresses migration velocity of osteoblasts in G1 phase but not in G1 /S nor in G2 /M phase. Finally, these observations on isoproterenol regulation of osteoblastic migration and cell cycle transition are opposite to the PTH actions in osteoblasts. In summary, we discovered that sympathetic tone regulates osteoblastic migration in association with cell cycle transition by using FUCCI system.

  13. Laser-based microfabrication for cell adhesion and migration

    NASA Astrophysics Data System (ADS)

    Miller, Jordan S.

    Mammalian cell adhesion and migration impact a multitude of cellular behaviors and tissue remodeling processes. Over the past several decades, investigators have methodically improved in vitro systems as mimics of the extracellular microenvironment to study these biologic phenomena. Experiments have progressed from early studies on bifunctional inorganic surfaces to those with purified adhesive proteins against an organic, non-adhesive background. Recently, subcellular geometric patterns of adhesive proteins have proven useful to restrict and direct focal contact formation, cell survival, lamellopodia extension, and the maturation of "supermature" focal contacts. The vast majority of recent studies have involved the construction of hydrophobic patches with adsorbed fibronectin as the adhesive constraint of choice. However, the extracellular matrix (ECM) in which cells operate is a complex and diverse environment where numerous signals interact with a cell simultaneously; signals that the cell must integrate and that directly impact these processes. Microfabrication methods to approximate the extracellular milieu have significant limitations in their potential to be extended to pattern multiple bioactive ligands with high precision. Current techniques require multi-step processes which lose feature fidelity at every pattern transfer step, while simultaneously increasing logistical complexity and the chance of technical missteps. We have developed a family of complementary techniques using the raster-scanning laser of a confocal microscope to address a number of current challenges in improving microfabrication. For our work with thin films of self-assembled organic monolayers, we systematically removed the multi-step processing requirements of conventional photolithographic microfabrication and characterized and verified the technical advantages of our new patterning techniques. For 3D work, we developed and demonstrated micron-scale biochemical and mechanical

  14. 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

  15. Cell migration microfluidics for electrotaxis-based heterogeneity study of lung cancer cells.

    PubMed

    Li, Yaping; Xu, Tao; Zou, Heng; Chen, Xiaomei; Sun, Dong; Yang, Mengsu

    2017-03-15

    Tumor metastasis involves the migration of cells from primary site to a distant location. Recently, it was established that cancer cells from the same tumor were heterogeneous in migratory ability. Numerous studies have demonstrated that cancer cells undergo reorientation and migration directionally under physiological electric field (EF), which has potential implications in metastasis. Microfluidic devices with channel structures of defined dimensions provide controllable microenvironments to enable real-time observation of cell migration. In this study, we developed two polydimethylsiloxane (PDMS)-based microfluidic devices for long-term electrotaxis study. In the first chip, three different intensities of EFs were generated in a single channel to study cell electrotactic behavior with high efficiency. We observed that the lung adenocarcinoma H1975 cells underwent cathodal migration with changing cellular orientation. To address the issue of cell electrotactic heterogeneity, we also developed a cell isolation device integrating cell immobilization structure, stable EF generator and cell retrieval module in one microfluidic chip to sort out different cell subpopulations based on electrotactic ability. High electrotactic and low electrotactic cells were harvested separately for colony formation assay and transcriptional analysis of migration-related genes. The results showed that H1975 cell motility was related to EGFR expression in the absence of EF stimulation, while in the presence of EF it was associated with PTEN expression. Up-regulation of RhoA was observed in cells with high motility, regardless of EF. The easy cell manipulation and precise field control of the microfluidic devices may enable further study of tumor heterogeneity in complex electrotactic environments.

  16. Fabrication of microfluidic system for the assessment of cell migration on 3D micropatterned substrates.

    PubMed

    Lee, Eun-Joong; Hwang, Chang-Mo; Baek, Dong-Hyun; Lee, Sang-Hoon

    2009-01-01

    Cell migration and proliferation are major process in wound healing, cancer metastasis and organogenesis during development. Many cells are related to recovery process of wound. Especially, fibroblasts act an important role in wound healing. Various cytokines such as platelet derived growth factor (PDGF) can induce fibroblast migration and widely studied to investigate the cell response under controlled cytokine microenvironments during wound healing. In real tissue healing process, cell microenvironments change with tissue types and anatomical characteristics of organs. With microfluidic system, we tried to mimic the natural microenvironment of wound healing, with gradient of PDGF, a fibroblast migration inducing cytokine, and patterned substrate with different orientation to PDGF gradient. Fibroblasts cultured in PDGF gradient micro fluidic chip showed cell migration under various micro environmental gradient conditions. Cells were cultured under PDGF gradient condition and different substrate pattern. Mouse fibroblast L929 cells were cultured in the microfluidic gradient. The results showed that most cells migrated along the substrate topological patterns under high concentration of PDGF. We developed long range sustaining micro fluidic channel and could analyze cell migration along the gradient of PDGF. Also, the cell migration on patterned extracellular environment shows that cells migrate along the extracellular 3D pattern rather than directly along the cytokine gradient when the pattern height is less than 1 microm. In this study, we could demonstrate that the extracellular pattern is more dominant to cell migration in combination with cytokine gradient in the wounded tissue when the environmental cues are 20 microm.

  17. Fluorescence-based assays for in vitro analysis of cell adhesion and migration.

    PubMed

    Spessotto, Paola; Lacrima, Katia; Nicolosi, Pier Andrea; Pivetta, Eliana; Scapolan, Martina; Perris, Roberto

    2009-01-01

    Cell adhesion and cell migration are two primary cellular phenomena for which in vitro approaches may be exploited to effectively dissect the individual events and underlying molecular mechanisms. The use of assays dedicated to the analysis of cell adhesion and migration in vitro also afford an efficient way of conducting larger basic and applied research screenings on the factors affecting these processes and are potentially exploitable in the context of routine diagnostic, prognostic, and predictive tests in the biological and medical fields. Therefore, there is a longstanding continuum in the interest in devising more rationale such assays and major contributions in this direction have been provided by the advent of procedures based on fluorescence cell tagging, the design of instruments capable of detecting fluorescent signals with high sensitivity, and informatic tools allowing sophisticated elaboration of data generated through these instruments. In this report, we describe three representative fluorescence-based model assays for the qualitative and quantitative assessment of cell adhesion and cell locomotion in static and dynamic conditions. The assays are easily performed, accurate and reproducible, and can be automated for high-to-medium throughput screenings of cell behavior in vitro. Performance of the assays involves the use of certain dedicated disposable accessories, which are commercially available, and a few instruments that, due to their versatility, can be regarded as constituents of a more generic laboratory setup.

  18. Rat hepatic stellate cells alter the gene expression profile and promote the growth, migration and invasion of hepatocellular carcinoma cells.

    PubMed

    Wang, Zhi-Ming; Zhou, Le-Yuan; Liu, Bin-Bin; Jia, Qin-An; Dong, Yin-Ying; Xia, Yun-Hong; Ye, Sheng-Long

    2014-10-01

    The aim of the present study was to examine the effects of activated hepatic stellate cells (HSCs) and their paracrine secretions, on hepatocellular cancer cell growth and gene expression in vitro and in vivo. Differentially expressed genes in McA-RH7777 hepatocellular carcinoma (HCC) cells following non-contact co-culture with activated stellate cells, were identified by a cDNA microarray. The effect of the co-injection of HCC cells and activated HSCs on tumor size in rats was also investigated. Non-contact co-culture altered the expression of 573 HCC genes by >2-fold of the control levels. Among the six selected genes, ELISA revealed increased protein levels of hepatic growth factor, matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9). Incubation of HCC cells with medium conditioned by activated HSCs significantly increased the proliferation rate (P<0.001), migration rate and the number of invasive HCC cells (P=0.001). Co-injection of HCC cells and activated HSCs into rats significantly increased the weight of the resulting HCC tumors (P<0.01). The paracrine activity of activated HSCs markedly altered the gene expression profile of HCC cells and affected their growth, migration and invasiveness. The results from the present study indicate that the interaction between the activated HSCs and HCC has an important role in the development of HCC.

  19. Quantification of Multicellular Organization, Junction Integrity, and Substrate Features in Collective Cell Migration.

    PubMed

    Canver, Adam C; Morss Clyne, Alisa

    2017-02-01

    Quantitative analysis of multicellular organization, cell-cell junction integrity, and substrate properties is essential to understand the mechanisms underlying collective cell migration. However, spatially and temporally defining these properties is difficult within collectively migrating cell groups due to challenges in accurate cell segmentation within the monolayer. In this paper, we present Matlab®-based algorithms to spatially quantify multicellular organization (migration distance, interface roughness, and cell alignment, area, and morphology), cell-cell junction integrity, and substrate features in confocal microscopy images of two-dimensional collectively migrating endothelial monolayers. We used novel techniques, including measuring the migrating front roughness using a parametric curve formulation, automatically binning cells to obtain data as a function of distance from the migrating front, using iterative morphological closings to fully define cell boundaries, quantifying β-catenin localization as a measure of cell-cell junction integrity, and skeletonizing fibronectin to determine fiber length and orientation. These algorithms are widely accessible, as they use common fluorescent markers and Matlab® functions, and provide high-throughput critical feature quantification within collectively migrating cell groups. These image analysis algorithms can help standardize feature quantification among different experimental techniques, cell types, and research groups studying collective cell migration.

  20. Relationship between neuronal migration and cell-substratum adhesion: laminin and merosin promote olfactory neuronal migration but are anti- adhesive

    PubMed Central

    1991-01-01

    Regulation by the extracellular matrix (ECM) of migration, motility, and adhesion of olfactory neurons and their precursors was studied in vitro. Neuronal cells of the embryonic olfactory epithelium (OE), which undergo extensive migration in the central nervous system during normal development, were shown to be highly migratory in culture as well. Migration of OE neuronal cells was strongly dependent on substratum- bound ECM molecules, being specifically stimulated and guided by laminin (or the laminin-related molecule merosin) in preference to fibronectin, type I collagen, or type IV collagen. Motility of OE neuronal cells, examined by time-lapse video microscopy, was high on laminin-containing substrata, but negligible on fibronectin substrata. Quantitative assays of adhesion of OE neuronal cells to substrata treated with different ECM molecules demonstrated no correlation, either positive or negative, between the migratory preferences of cells and the strength of cell-substratum adhesion. Moreover, measurements of cell adhesion to substrata containing combinations of ECM proteins revealed that laminin and merosin are anti-adhesive for OE neuronal cells, i.e., cause these cells to adhere poorly to substrata that would otherwise be strongly adhesive. The evidence suggests that the anti- adhesive effect of laminin is not the result of interactions between laminin and other ECM molecules, but rather an effect of laminin on cells, which alters the way in which cells adhere. Consistent with this view, laminin was found to interfere strongly with the formation of focal contacts by OE neuronal cells. PMID:1918163

  1. Putting the brakes on cancer cell migration: JAM-A restrains integrin activation.

    PubMed

    Naik, Ulhas P; Naik, Meghna U

    2008-01-01

    Junctional Adhesion Molecule A (JAM-A) is a member of the Ig superfamily of membrane proteins expressed in platelets, leukocytes, endothelial cells and epithelial cells. We have previously shown that in endothelial cells, JAM-A regulates basic fibroblast growth factor, (FGF-2)-induced angiogenesis via augmenting endothelial cell migration. Recently, we have revealed that in breast cancer cells, downregulation of JAM-A enhances cancer cell migration and invasion. Further, ectopic expression of JAM-A in highly metastatic MDA-MB-231 cells attenuates cell migration, and downregulation of JAM-A in low-metastatic T47D cells enhance migration. Interestingly, JAM-A expression is greatly diminished as breast cancer disease progresses. The molecular mechanism of this function of JAM-A is beyond its well-characterized barrier function at the tight junction. Our results point out that JAM-A differentially regulates migration of endothelial and cancer cells.

  2. Dynamic filopodia are required for chemokine-dependent intracellular polarization during guided cell migration in vivo.

    PubMed

    Meyen, Dana; Tarbashevich, Katsiaryna; Banisch, Torsten U; Wittwer, Carolina; Reichman-Fried, Michal; Maugis, Benoît; Grimaldi, Cecilia; Messerschmidt, Esther-Maria; Raz, Erez

    2015-04-15

    Cell migration and polarization is controlled by signals in the environment. Migrating cells typically form filopodia that extend from the cell surface, but the precise function of these structures in cell polarization and guided migration is poorly understood. Using the in vivo model of zebrafish primordial germ cells for studying chemokine-directed single cell migration, we show that filopodia distribution and their dynamics are dictated by the gradient of the chemokine Cxcl12a. By specifically interfering with filopodia formation, we demonstrate for the first time that these protrusions play an important role in cell polarization by Cxcl12a, as manifested by elevation of intracellular pH and Rac1 activity at the cell front. The establishment of this polarity is at the basis of effective cell migration towards the target. Together, we show that filopodia allow the interpretation of the chemotactic gradient in vivo by directing single-cell polarization in response to the guidance cue.

  3. RHO binding to FAM65A regulates Golgi reorientation during cell migration

    PubMed Central

    Marshall, Christopher J.

    2016-01-01

    ABSTRACT Directional cell migration involves reorientation of the secretory machinery. However, the molecular mechanisms that control this reorientation are not well characterised. Here, we identify a new Rho effector protein, named FAM65A, which binds to active RHOA, RHOB and RHOC. FAM65A links RHO proteins to Golgi-localising cerebral cavernous malformation-3 protein (CCM3; also known as PDCD10) and its interacting proteins mammalian STE20-like protein kinases 3 and 4 (MST3 and MST4; also known as STK24 and STK26, respectively). Binding of active RHO proteins to FAM65A does not affect the kinase activity of MSTs but results in their relocation from the Golgi in a CCM3-dependent manner. This relocation is crucial for reorientation of the Golgi towards the leading edge and subsequent directional cell migration. Our results reveal a previously unidentified pathway downstream of RHO that regulates the polarity of migrating cells through Golgi reorientation in a FAM65A-, CCM3- and MST3- and MST4-dependent manner. PMID:27807006

  4. RHO binding to FAM65A regulates Golgi reorientation during cell migration.

    PubMed

    Mardakheh, Faraz K; Self, Annette; Marshall, Christopher J

    2016-12-15

    Directional cell migration involves reorientation of the secretory machinery. However, the molecular mechanisms that control this reorientation are not well characterised. Here, we identify a new Rho effector protein, named FAM65A, which binds to active RHOA, RHOB and RHOC. FAM65A links RHO proteins to Golgi-localising cerebral cavernous malformation-3 protein (CCM3; also known as PDCD10) and its interacting proteins mammalian STE20-like protein kinases 3 and 4 (MST3 and MST4; also known as STK24 and STK26, respectively). Binding of active RHO proteins to FAM65A does not affect the kinase activity of MSTs but results in their relocation from the Golgi in a CCM3-dependent manner. This relocation is crucial for reorientation of the Golgi towards the leading edge and subsequent directional cell migration. Our results reveal a previously unidentified pathway downstream of RHO that regulates the polarity of migrating cells through Golgi reorientation in a FAM65A-, CCM3- and MST3- and MST4-dependent manner.

  5. Advances in wound-healing assays for probing collective cell migration.

    PubMed

    Riahi, Reza; Yang, Yongliang; Zhang, Donna D; Wong, Pak Kin

    2012-02-01

    Collective cell migration plays essential roles in a wide spectrum of biological processes, such as embryogenesis, tissue regeneration, and cancer metastasis. Numerous wound-healing assays based on mechanical, chemical, optical, and electrical approaches have been developed to create model "wounds" in cell monolayers to study the collective cell migration processes. These approaches can result in different microenvironments for cells to migrate and possess diverse assay characteristics in terms of simplicity, throughput, reproducibility, and multiplexability. In this review, we provide an overview of advances in wound-healing assays and discuss their advantages and limitations in studying collective cell migration.

  6. Transspinal direct current stimulation modulates migration and proliferation of adult newly born spinal cells in mice.

    PubMed

    Samaddar, Sreyashi; Vazquez, Kizzy; Ponkia, Dipen; Toruno, Pedro; Sahbani, Karim; Begum, Sultana; Abouelela, Ahmed; Mekhael, Wagdy; Ahmed, Zaghloul

    2017-02-01

    Direct current electrical fields have been shown to be a major factor in the regulation of cell proliferation, differentiation, migration, and survival, as well as in the maturation of dividing cells during development. During adulthood, spinal cord cells are continuously produced in both animals and humans, and they hold great potential for neural restoration following spinal cord injury. While the effects of direct current electrical fields on adult-born spinal cells cultured ex vivo have recently been reported, the effects of direct current electrical fields on adult-born spinal cells in vivo have not been characterized. Here, we provide convincing findings that a therapeutic form of transspinal direct current stimulation (tsDCS) affects the migration and proliferation of adult-born spinal cells in mice. Specifically, cathodal tsDCS attracted the adult-born spinal cells, while anodal tsDCS repulsed them. In addition, both tsDCS polarities caused a significant increase in cell number. Regarding the potential mechanisms involved, both cathodal and anodal tsDCS caused significant increases in expression of brain-derived neurotrophic factor, while expression of nerve growth factor increased and decreased, respectively. In the spinal cord, both anodal and cathodal tsDCS increased blood flow. Since blood flow and angiogenesis are associated with the proliferation of neural stem cells, increased blood flow may represent a major factor in the modulation of newly born spinal cells by tsDCS. Consequently, we propose that the method and novel findings presented in the current study have the potential to facilitate cellular, molecular, and/or bioengineering strategies to repair injured spinal cords.NEW & NOTEWORTHY Our results indicate that transspinal direct current stimulation (tsDCS) affects the migratory pattern and proliferation of adult newly born spinal cells, a cell population which has been implicated in learning and memory. In addition, our results suggest a

  7. Down-regulation of MUC1 in cancer cells inhibits cell migration by promoting E-cadherin/catenin complex formation

    SciTech Connect

    Yuan Zhenglong; Wong, Sandy; Borrelli, Alexander; Chung, Maureen A.

    2007-10-26

    MUC1, a tumor associated glycoprotein, is over-expressed in most cancers and can promote proliferation and metastasis. The objective of this research was to study the role of MUC1 in cancer metastasis and its potential mechanism. Pancreatic (PANC1) and breast (MCF-7) cancer cells with stable 'knockdown' of MUC1 expression were created using RNA interference. {beta}-Catenin and E-cadherin protein expression were upregulated in PANC1 and MCF-7 cells with decreased MUC1 expression. Downregulation of MUC1 expression also induced {beta}-catenin relocation from the nucleus to the cytoplasm, increased E-cadherin/{beta}-catenin complex formation and E-cadherin membrane localization in PANC1 cells. PANC1 cells with 'knockdown' MUC1 expression had decreased in vitro cell invasion. This study suggested that MUC1 may affect cancer cell migration by increasing E-cadherin/{beta}-catenin complex formation and restoring E-cadherin membrane localization.

  8. Down-regulation of MUC1 in cancer cells inhibits cell migration by promoting E-cadherin/catenin complex formation.

    PubMed

    Yuan, Zhenglong; Wong, Sandy; Borrelli, Alexander; Chung, Maureen A

    2007-10-26

    MUC1, a tumor associated glycoprotein, is over-expressed in most cancers and can promote proliferation and metastasis. The objective of this research was to study the role of MUC1 in cancer metastasis and its potential mechanism. Pancreatic (PANC1) and breast (MCF-7) cancer cells with stable 'knockdown' of MUC1 expression were created using RNA interference. beta-Catenin and E-cadherin protein expression were upregulated in PANC1 and MCF-7 cells with decreased MUC1 expression. Downregulation of MUC1 expression also induced beta-catenin relocation from the nucleus to the cytoplasm, increased E-cadherin/beta-catenin complex formation and E-cadherin membrane localization in PANC1 cells. PANC1 cells with 'knockdown' MUC1 expression had decreased in vitro cell invasion. This study suggested that MUC1 may affect cancer cell migration by increasing E-cadherin/beta-catenin complex formation and restoring E-cadherin membrane localization.

  9. 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

  10. Effect of targeted silencing of IL-8 on in vitro migration and invasion of SKOV3 ovarian cancer cells

    PubMed Central

    Li, Yanyu; Liu, Ling; Yin, Zeyuan; Xu, Hui; Li, Shuang; Tao, Wei; Cheng, Hui; Du, Lei; Zhou, Xueyuan; Zhang, Bei

    2017-01-01

    The aim of the study was to determine whether interleukin-8 (IL-8) affects human SKOV3 ovarian cancer cell migration and invasion by targeting silencing of IL-8 expression. Silencing small-interfering RNA (siRNA) targeting IL-8 gene was constructed to infect SKOV3 cells by lentiviral vector. The expression of IL-8 and p-nuclear factor (NF)-κB protein was detected by western blot analysis. The wound scratch and Transwell tests were used to assay the cell migration and invasiveness of SKOV3 cells infected with lentiviral vector targeting IL-8 gene siRNA. The levels of IL-8 protein expressed by SKOV3 cells infected by lentiviral vector targeting IL-8 gene siRNA decreased by 72.3%. IL-8 (50 ng/ml) increased the ability of SKOV3 cells to suppress cell migration (p<0.01). Cisplatin and silencing of IL-8 achieved the ability to inhibit SKOV3 cell invasion (p<0.01), and 100 ng/ml concentration of IL-8 enhanced the ability of SKOV3 invasion (p<0.01). Silencing of IL-8 to a certain extent reduced the expression of p-NF-κB proteins, but it was not statistically significant. In conclusion, silencing of IL-8 may inhibit the migration and invasion of SKOV3 cells, which may be independent of the p-NF-κB protein. PMID:28356930

  11. 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.

  12. Seeds of Locally Aligned Motion and Stress Coordinate a Collective Cell Migration

    PubMed Central

    Zaritsky, Assaf; Welf, Erik S.; Tseng, Yun-Yu; Angeles Rabadán, M.; Serra-Picamal, Xavier; Trepat, Xavier; Danuser, Gaudenz

    2015-01-01

    We find how collective migration emerges from mechanical information transfer between cells. Local alignment of cell velocity and mechanical stress orientation—a phenomenon dubbed “plithotaxis”—plays a crucial role in inducing coordinated migration. Leader cells at the monolayer edge better align velocity and stress to migrate faster toward the open space. Local seeds of enhanced motion then generate stress on neighboring cells to guide their migration. Stress-induced motion propagates into the monolayer as well as along the monolayer boundary to generate increasingly larger clusters of coordinately migrating cells that move faster with enhanced alignment of velocity and stress. Together, our analysis provides a model of long-range mechanical communication between cells, in which plithotaxis translates local mechanical fluctuations into globally collective migration of entire tissues. PMID:26682808

  13. 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

  14. β-Catenin promotes cell proliferation, migration, and invasion but induces apoptosis in renal cell carcinoma

    PubMed Central

    Yang, Chun-ming; Ji, Shan; Li, Yan; Fu, Li-ye; Jiang, Tao; Meng, Fan-dong

    2017-01-01

    β-Catenin (CTNNB1 gene coding protein) is a component of the Wnt signaling pathway that has been shown to play an important role in the formation of certain cancers. Abnormal accumulation of CTNNB1 contributes to most cancers. This research studied the involvement of β-catenin in renal cell carcinoma (RCC) cell proliferation, apoptosis, migration, and invasion. Proliferation, cell cycle, and apoptosis were analyzed by using Cell Counting Kit-8 and by flow cytometry. Migration and invasion assays were measured by transwell analysis. Real-time polymerase chain reaction and Western blot analysis were used to detect the expression of CTNNB1, ICAM-1, VCAM-1, CXCR4, and CCL18 in RCC cell lines. It was found that CTNNB1 knockdown inhibited cell proliferation, migration, and invasion and induced apoptosis of A-498 cells. CTNNB1 overexpression promoted cell proliferation, migration, and invasion and inhibited apoptosis of 786-O cells. Moreover, knockdown of CTNNB1 decreased the levels of ICAM-1, VCAM-1, CXCR4, and CCL18 expression, but CTNNB1 overexpression increased the expression of ICAM-1, VCAM-1, CXCR4, and CCL18. Further in vivo tumor formation study in nude mice indicated that inhibition of CTNNB1 delayed the progress of tumor formation through inhibiting PCNA and Ki67 expression. These results indicate that CTNNB1 could act as an oncogene and may serve as a promising therapeutic strategy for RCC. PMID:28260916

  15. 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

  16. 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

  17. 532 nm Low-Power Laser Irradiation Facilitates the Migration of GABAergic Neural Stem/Progenitor Cells in Mouse Neocortex

    PubMed Central

    Fukuzaki, Yumi; Shin, Hyeryun; Kawai, Hideki D.; Yamanoha, Banri; Kogure, Shinichi

    2015-01-01

    Background and Objective Accumulating evidence has shown that low-power laser irradiation (LLI) affects cell proliferation and survival, but little is known about LLI effects on neural stem/progenitor cells (NSPCs). Here we investigate whether transcranial 532 nm LLI affects NSPCs in adult murine neocortex and in neurospheres from embryonic mice. Study Design/Materials and Methods We applied 532 nm LLI (Nd:YVO4, CW, 60 mW) on neocortical surface via cranium in adult mice and on cultured cells from embryonic mouse brains in vitro to investigate the proliferation and migration of NSPCs and Akt expression using immunohistochemical assays and Western blotting techniques. Results In vivo experiments demonstrated that 532 nm LLI significantly facilitated the migration of GABAergic NSPCs that were induced to proliferate in layer 1 by mild ischemia. In vitro experiments using GABAergic NSPCs derived from embryonic day 14 ganglionic eminence demonstrated that 532 nm LLI for 60 min promoted the migration of GAD67-immunopositive NSPCs with a significant increase of Akt expression. Meanwhile, the LLI induced proliferation, but not migration, of NSPCs that give rise to excitatory neurons. Conclusion It is concluded that 532 nm LLI promoted the migration of GABAergic NSPCs into deeper layers of the neocortex in vivo by elevating Akt expression. PMID:25919297

  18. Long non-coding RNA small nucleolar RNA host gene 12 (SNHG12) promotes cell proliferation and migration by upregulating angiomotin gene expression in human osteosarcoma cells.

    PubMed

    Ruan, Wendong; Wang, Pei; Feng, Shiqing; Xue, Yuan; Li, Yulin

    2016-03-01

    The long non-coding RNA (lncRNA) small nucleolar RNA host gene 12 (SNHG12) has a role in cell proliferation and migration. Angiomotin, encoded by the AMOT gene, is a protein that regulates the migration and organization of endothelial cells. SNHG12 and AMOT have been shown to play a role in a variety of human cancers but have yet to be studied in detail in human osteosarcoma. Tissue samples from primary osteosarcoma (n = 20) and adjacent normal tissues (n = 20), the osteosarcoma cell lines, SAOS-2, MG-63, U-2 OS, and the human osteoblast cell line hFOB (OB3) were studied using Western blot for angiomotin, and quantitative real-time polymerase chain reaction for the expression of SNHG12 and AMOT. The expression of SNHG12 was knocked down using RNA interference. Cell migration assays were performed. Cell apoptosis was studied using flow cytometry. SNHG12 and AMOT messenger RNA (mRNA) expression was upregulated in osteosarcoma tissues and cell lines when compared with normal tissues and cells. Upregulation of AMOT mRNA was associated with upregulation of SNHG12. Knockdown of SNHG12 reduced the expression of angiomotin in osteosarcoma cells and suppressed cell proliferation and migration but did not affect cell apoptosis. This preliminary study has shown that the lncRNA SNHG12 promotes cell proliferation and migration by upregulating AMOT gene expression in osteosarcoma cells in vivo and in vitro. Further studies are recommended to investigate the role of SNHG12 and AMOT expression in tumor cell proliferation and migration and angiogenesis in osteosarcoma and a range of malignant mesenchymal tumors.

  19. Overexpression of Selenoprotein SelK in BGC-823 Cells Inhibits Cell Adhesion and Migration.

    PubMed

    Ben, S B; Peng, B; Wang, G C; Li, C; Gu, H F; Jiang, H; Meng, X L; Lee, B J; Chen, C L

    2015-10-01

    Effects of human selenoprotein SelK on the adhesion and migration ability of human gastric cancer BGC-823 cells using Matrigel adhesion and transwell migration assays, respectively, were investigated in this study. The Matrigel adhesion ability of BGC-823 cells that overexpressed SelK declined extremely significantly (p < 0.01) compared with that of the cells not expressing the protein. The migration ability of BGC-823 cells that overexpressed SelK also declined extremely significantly (p < 0.01). On the other hand, the Matrigel adhesion ability and migration ability of the cells that overexpressed C-terminally truncated SelK did not decline significantly. The Matrigel adhesion ability and migration ability of human embryonic kidney HEK-293 cells that overexpressed SelK did not show significant change (p > 0.05) with the cells that overexpressed the C-terminally truncated protein. In addition to the effect on Matrigel adhesion and migration, the overexpression of SelK also caused a loss in cell viability (as measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) colorimetric assay) and induced apoptosis as shown by confocal microscopy and flow cytometry. The cytosolic free Ca2+ level of these cells was significantly increased as detected by flow cytometry. But the overexpression of SelK in HEK-293 cells caused neither significant loss in cell viability nor apoptosis induction. Only the elevation of cytosolic free Ca2+ level in these cells was significant. Taken together, the results suggest that the overexpression of SelK can inhibit human cancer cell Matrigel adhesion and migration and cause both the loss in cell viability and induction of apoptosis. The release of intracellular Ca2+ from the endoplasmic reticulum might be a mechanism whereby the protein exerted its impact. Furthermore, only the full-length protein, but not C-terminally truncated form, was capable of producing such impact. The embryonic cells were not influenced by the

  20. Novel protein Callipygian defines the back of migrating cells

    PubMed Central

    Swaney, Kristen F.; Borleis, Jane; Iglesias, Pablo A.; Devreotes, Peter N.

    2015-01-01

    Asymmetric protein localization is essential for cell polarity and migration. We report a novel protein, Callipygian (CynA), which localizes to the lagging edge before other proteins and becomes more tightly restricted as cells polarize; additionally, it accumulates in the cleavage furrow during cytokinesis. CynA protein that is tightly localized, or “clustered,” to the cell rear is immobile, but when polarity is disrupted, it disperses throughout the membrane and responds to uniform chemoattractant stimulation by transiently localizing to the cytosol. These behaviors require a pleckstrin homology-domain membrane tether and a WD40 clustering domain, which can also direct other membrane proteins to the back. Fragments of CynA lacking the pleckstrin homology domain, which are normally found in the cytosol, localize to the lagging edge membrane when coexpressed with full-length protein, showing that CynA clustering is mediated by oligomerization. Cells lacking CynA have aberrant lateral protrusions, altered leading-edge morphology, and decreased directional persistence, whereas those overexpressing the protein display exaggerated features of polarity. Consistently, actin polymerization is inhibited at sites of CynA accumulation, thereby restricting protrusions to the opposite edge. We suggest that the mutual antagonism between CynA and regions of responsiveness creates a positive feedback loop that restricts CynA to the rear and contributes to the establishment of the cell axis. PMID:26130809

  1. 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

  2. A Macroscopic Mathematical Model for Cell Migration Assays Using a Real-Time Cell Analysis.

    PubMed

    Di Costanzo, Ezio; Ingangi, Vincenzo; Angelini, Claudia; Carfora, Maria Francesca; Carriero, Maria Vincenza; Natalini, Roberto

    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.

  3. 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.

  4. Brain-derived Neurotrophic Factor Promotes the Migration of Olfactory Ensheathing Cells Through TRPC Channels.

    PubMed

    Wang, Ying; Teng, Hong-Lin; Gao, Yuan; Zhang, Fan; Ding, Yu-Qiang; Huang, Zhi-Hui

    2016-12-01

    Olfactory ensheathing cells (OECs) are a unique type of glial cells with axonal growth-promoting properties in the olfactory system. Organized migration of OECs is essential for neural regeneration and olfactory development. However, the molecular mechanism of OEC migration remains unclear. In the present study, we examined the effects of brain-derived neurotrophic factor (BDNF) on OEC migration. Initially, the "scratch" migration assay, the inverted coverslip and Boyden chamber migration assays showed that BDNF could promote the migration of primary cultured OECs. Furthermore, BDNF gradient attracted the migration of OECs in single-cell migration assays. Mechanistically, TrkB receptor expressed in OECs mediated BDNF-induced OEC migration, and BDNF triggered calcium signals in OECs. Finally, transient receptor potential cation channels (TRPCs) highly expressed in OECs were responsible for BDNF-induced calcium signals, and required for BDNF-induced OEC migration. Taken together, these results demonstrate that BDNF promotes the migration of cultured OECs and an unexpected finding is that TRPCs are required for BDNF-induced OEC migration. GLIA 2016;64:2154-2165.

  5. Macrophage migration inhibitory factor promotes cell death and aggravates neurologic deficits after experimental stroke.

    PubMed

    Inácio, Ana R; Ruscher, Karsten; Leng, Lin; Bucala, Richard; Deierborg, Tomas

    2011-04-01

    Multiple mechanisms contribute to tissue demise and functional recovery after stroke. We studied the involvement of macrophage migration inhibitory factor (MIF) in cell death and development of neurologic deficits after experimental stroke. Macrophage migration inhibitory factor is upregulated in the brain after cerebral ischemia, and disruption of the Mif gene in mice leads to a smaller infarct volume and better sensory-motor function after transient middle cerebral artery occlusion (tMCAo). In mice subjected to tMCAo, we found that MIF accumulates in neurons of the peri-infarct region, particularly in cortical parvalbumin-positive interneurons. Likewise, in cultured cortical neurons exposed to oxygen and glucose deprivation, MIF levels increase, and inhibition of MIF by (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid methyl ester (ISO-1) protects against cell death. Deletion of MIF in Mif(-/-) mice does not affect interleukin-1β protein levels in the brain and serum after tMCAo. Furthermore, disruption of the Mif gene in mice does not affect CD68, but it is associated with higher galectin-3 immunoreactivity in the brain after tMCAo, suggesting that MIF affects the molecular/cellular composition of the macrophages/microglia response after experimental stroke. We conclude that MIF promotes neuronal death and aggravates neurologic deficits after experimental stroke, which implicates MIF in the pathogenesis of neuronal injury after stroke.

  6. Y-27632 Increases Sensitivity of PANC-1 Cells to EGCG in Regulating Cell Proliferation and Migration.

    PubMed

    Liu, Xing; Bi, Yongyi

    2016-10-03

    BACKGROUND The study aimed to investigate the inhibitory effect of (1R,4r)-4-((R)-1-aminoethyl)-N-(pyridin-4-yl) cyclohexanecarboxamide (Y-27632) and (-)-epigallocatechin-3-gallate (EGCG) on the proliferation and migration of PANC-1 cells. EGCG, found in green tea, has been previously shown to be one of the most abundant and powerful catechins in cancer prevention and treatment. Y-27632, a selective inhibitor of rho-associated protein kinase 1, is widely used in treating cardiovascular disease, inflammation, and cancer. MATERIAL AND METHODS PANC-1 cells, maintained in Dulbecco's Modified Eagle's Medium, were treated with dimethyl sulfoxide (control) as well as different concentrations (20, 40, 60, and 80 μg/mL) of EGCG for 48 h. In addition, PANC-1 cells were treated separately with 60 μg/mL EGCG, 20 μM Y-27632, and EGCG combined with Y-27632 (60 μg/mL EGCG + 20 μM Y-27632) for 48 h. The effect of EGCG and Y-27632 on the proliferation and migration of PANC-1 cells was evaluated using Cell Counting Kit-8 and transwell migration assays. The expression of peroxisome proliferator-activated receptor alpha (PPARα) and Caspase-3 mRNA was determined by Quantitative real-time polymerase chain reaction (RT-qPCR). RESULTS EGCG (20-80 μg/mL) inhibited cell viability in a dose-dependent manner. Y-27632 enhanced the sensitivity of PANC-1 cells to EGCG (by increasing the expression of PPARa and Caspase-3 mRNA) and suppressed cell proliferation. PANC-1 cell migration was inhibited by treatment with a combination of EGCG and Y-27632. CONCLUSIONS Y-27632 increases the sensitivity of PANC-1 cells to EGCG in regulating cell proliferation and migration, which is likely to be related to the expression of PPARa mRNA and Caspase-3 mRNA.

  7. 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.

  8. 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.

  9. Crossing barriers: the new dimension of 2D cell migration assays.

    PubMed

    Van Horssen, Remco; ten Hagen, Timo L M

    2011-01-01

    In our body cells move in three dimensions, embedded in an extracellular matrix that varies in composition, density and stiffness, and this movement is fundamental to life. Next to 3D cell migration assays, representing these physiological circumstances, still we need 2D migrations assays to perform detailed studies on the contribution of matrix-components and (extra)cellular proteins to cell movements. Next to the debate on differences between 3D and 2D migration, there also are many new perspectives on the use and development of novel or modified 2D cell migration assays. Of special significance is the introduction of so-called barrier migration assays, methods that avoid cell and matrix damage, as complementation or replacement of scratch/wound healing assays. Here, we discuss the possibilities and limitations of different 2D barrier migration assays.

  10. Inhibition of FAAH confers increased stem cell migration via PPARα.

    PubMed

    Wollank, Yvonne; Ramer, Robert; Ivanov, Igor; Salamon, Achim; Peters, Kirsten; Hinz, Burkhard

    2015-10-01

    Regenerative activity in tissues of mesenchymal origin depends on the migratory potential of mesenchymal stem cells (MSCs). The present study focused on inhibitors of the enzyme fatty acid amide hydrolase (FAAH), which catalyzes the degradation of endocannabinoids (anandamide, 2-arachidonoylglycerol) and endocannabinoid-like substances (N-oleoylethanolamine, N-palmitoylethanolamine). Boyden chamber assays, the FAAH inhibitors, URB597 and arachidonoyl serotonin (AA-5HT), were found to increase the migration of human adipose-derived MSCs. LC-MS analyses revealed increased levels of all four aforementioned FAAH substrates in MSCs incubated with either FAAH inhibitor. Following addition to MSCs, all FAAH substrates mimicked the promigratory action of FAAH inhibitors. Promigratory effects of FAAH inhibitors and substrates were causally linked to activation of p42/44 MAPKs, as well as to cytosol-to-nucleus translocation of the transcription factor, PPARα. Whereas PPARα activation by FAAH inhibitors and substrates became reversed upon inhibition of p42/44 MAPK activation, a blockade of PPARα left p42/44 MAPK phosphorylation unaltered. Collectively, these data demonstrate FAAH inhibitors and substrates to cause p42/44 MAPK phosphorylation, which subsequently activates PPARα to confer increased migration of MSCs. This novel pathway may be involved in regenerative effects of endocannabinoids whose degradation could be a target of pharmacological intervention by FAAH inhibitors.

  11. Inhibition of FAAH confers increased stem cell migration via PPARα

    PubMed Central

    Wollank, Yvonne; Ramer, Robert; Ivanov, Igor; Salamon, Achim; Peters, Kirsten; Hinz, Burkhard

    2015-01-01

    Regenerative activity in tissues of mesenchymal origin depends on the migratory potential of mesenchymal stem cells (MSCs). The present study focused on inhibitors of the enzyme fatty acid amide hydrolase (FAAH), which catalyzes the degradation of endocannabinoids (anandamide, 2-arachidonoylglycerol) and endocannabinoid-like substances (N-oleoylethanolamine, N-palmitoylethanolamine). Boyden chamber assays, the FAAH inhibitors, URB597 and arachidonoyl serotonin (AA-5HT), were found to increase the migration of human adipose-derived MSCs. LC-MS analyses revealed increased levels of all four aforementioned FAAH substrates in MSCs incubated with either FAAH inhibitor. Following addition to MSCs, all FAAH substrates mimicked the promigratory action of FAAH inhibitors. Promigratory effects of FAAH inhibitors and substrates were causally linked to activation of p42/44 MAPKs, as well as to cytosol-to-nucleus translocation of the transcription factor, PPARα. Whereas PPARα activation by FAAH inhibitors and substrates became reversed upon inhibition of p42/44 MAPK activation, a blockade of PPARα left p42/44 MAPK phosphorylation unaltered. Collectively, these data demonstrate FAAH inhibitors and substrates to cause p42/44 MAPK phosphorylation, which subsequently activates PPARα to confer increased migration of MSCs. This novel pathway may be involved in regenerative effects of endocannabinoids whose degradation could be a target of pharmacological intervention by FAAH inhibitors. PMID:26263913

  12. 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.

  13. Toll-like receptors on human mesenchymal stem cells drive their migration and immunomodulating responses.

    PubMed

    Tomchuck, Suzanne L; Zwezdaryk, Kevin J; Coffelt, Seth B; Waterman, Ruth S; Danka, Elizabeth S; Scandurro, Aline B

    2008-01-01

    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 initially established by reverse transcription-polymerase chain reaction 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 nuclear factor kappaB, 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, hMSC migration was promoted by TLR ligand exposure as demonstrated by transwell migration assays. Conversely, disruption of TLRs by neutralizing TLR antibodies compromised hMSC 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.

  14. 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

  15. 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.

  16. Fast-crawling cell types migrate to avoid the direction of periodic substratum stretching.

    PubMed

    Okimura, Chika; Ueda, Kazuki; Sakumura, Yuichi; Iwadate, Yoshiaki

    2016-07-03

    To investigate the relationship between mechanical stimuli from substrata and related cell functions, one of the most useful techniques is the application of mechanical stimuli via periodic stretching of elastic substrata. In response to this stimulus, Dictyostelium discoideum cells migrate in a direction perpendicular to the stretching direction. The origins of directional migration, higher migration velocity in the direction perpendicular to the stretching direction or the higher probability of a switch of migration direction to perpendicular to the stretching direction, however, remain unknown. In this study, we applied periodic stretching stimuli to neutrophil-like differentiated HL-60 cells, which migrate perpendicular to the direction of stretch. Detailed analysis of the trajectories of HL-60 cells and Dictyostelium cells obtained in a previous study revealed that the higher probability of a switch of migration direction to that perpendicular to the direction of stretching was the main cause of such directional migration. This directional migration appears to be a strategy adopted by fast-crawling cells in which they do not migrate faster in the direction they want to go, but migrate to avoid a direction they do not want to go.

  17. 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

  18. 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.

  19. 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

  20. Migration of tumor cells in 3D matrices is governed by matrix stiffness along with cell-matrix adhesion and proteolysis.

    PubMed

    Zaman, Muhammad H; Trapani, Linda M; Sieminski, Alisha L; Siemeski, Alisha; Mackellar, Drew; Gong, Haiyan; Kamm, Roger D; Wells, Alan; Lauffenburger, Douglas A; Matsudaira, Paul

    2006-07-18

    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 beta1 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.

  1. 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.

  2. Computational modelling of cell chain migration reveals mechanisms that sustain follow-the-leader behaviour.

    PubMed

    Wynn, Michelle L; Kulesa, Paul M; Schnell, Santiago

    2012-07-07

    Follow-the-leader chain migration is a striking cell migratory behaviour observed during vertebrate development, adult neurogenesis and cancer metastasis. Although cell-cell contact and extracellular matrix (ECM) cues have been proposed to promote this phenomenon, mechanisms that underlie chain migration persistence remain unclear. Here, we developed a quantitative agent-based modelling framework to test mechanistic hypotheses of chain migration persistence. We defined chain migration and its persistence based on evidence from the highly migratory neural crest model system, where cells within a chain extend and retract filopodia in short-lived cell contacts and move together as a collective. In our agent-based simulations, we began with a set of agents arranged as a chain and systematically probed the influence of model parameters to identify factors critical to the maintenance of the chain migration pattern. We discovered that chain migration persistence requires a high degree of directional bias in both lead and follower cells towards the target. Chain migration persistence was also promoted when lead cells maintained cell contact with followers, but not vice-versa. Finally, providing a path of least resistance in the ECM was not sufficient alone to drive chain persistence. Our results indicate that chain migration persistence depends on the interplay of directional cell movement and biased cell-cell contact.<