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Sample records for cell motility screen

  1. Cell Motility

    CERN Document Server

    Lenz, Peter

    2008-01-01

    Cell motility is a fascinating example of cell behavior which is fundamentally important to a number of biological and pathological processes. It is based on a complex self-organized mechano-chemical machine consisting of cytoskeletal filaments and molecular motors. In general, the cytoskeleton is responsible for the movement of the entire cell and for movements within the cell. The main challenge in the field of cell motility is to develop a complete physical description on how and why cells move. For this purpose new ways of modeling the properties of biological cells have to be found. This long term goal can only be achieved if new experimental techniques are developed to extract physical information from these living systems and if theoretical models are found which bridge the gap between molecular and mesoscopic length scales. Cell Motility gives an authoritative overview of the fundamental biological facts, theoretical models, and current experimental developments in this fascinating area.

  2. Cytoskeleton and Cell Motility

    CERN Document Server

    Risler, Thomas

    2011-01-01

    The present article is an invited contribution to the Encyclopedia of Complexity and System Science, Robert A. Meyers Ed., Springer New York (2009). It is a review of the biophysical mechanisms that underly cell motility. It mainly focuses on the eukaryotic cytoskeleton and cell-motility mechanisms. Bacterial motility as well as the composition of the prokaryotic cytoskeleton is only briefly mentioned. The article is organized as follows. In Section III, I first present an overview of the diversity of cellular motility mechanisms, which might at first glance be categorized into two different types of behaviors, namely "swimming" and "crawling". Intracellular transport, mitosis - or cell division - as well as other extensions of cell motility that rely on the same essential machinery are briefly sketched. In Section IV, I introduce the molecular machinery that underlies cell motility - the cytoskeleton - as well as its interactions with the external environment of the cell and its main regulatory pathways. Sec...

  3. NCAM regulates cell motility

    DEFF Research Database (Denmark)

    Prag, Søren; Lepekhin, Eugene A; Kolkova, Kateryna;

    2002-01-01

    Cell migration is required during development of the nervous system. The regulatory mechanisms for this process, however, are poorly elucidated. We show here that expression of or exposure to the neural cell adhesion molecule (NCAM) strongly affected the motile behaviour of glioma cells...... independently of homophilic NCAM interactions. Expression of the transmembrane 140 kDa isoform of NCAM (NCAM-140) caused a significant reduction in cellular motility, probably through interference with factors regulating cellular attachment, as NCAM-140-expressing cells exhibited a decreased attachment...... to a fibronectin substratum compared with NCAM-negative cells. Ectopic expression of the cytoplasmic part of NCAM-140 also inhibited cell motility, presumably via the non-receptor tyrosine kinase p59(fyn) with which NCAM-140 interacts. Furthermore, we showed that the extracellular part of NCAM acted as a paracrine...

  4. Stochastic models of cell motility

    DEFF Research Database (Denmark)

    Gradinaru, Cristian

    2012-01-01

    Cell motility and migration are central to the development and maintenance of multicellular organisms, and errors during this process can lead to major diseases. Consequently, the mechanisms and phenomenology of cell motility are currently under intense study. In recent years, a new...... interdisciplinary field focusing on the study of biological processes at the nanoscale level, with a range of technological applications in medicine and biological research, has emerged. The work presented in this thesis is at the interface of cell biology, image processing, and stochastic modeling. The stochastic...... models introduced here are based on persistent random motion, which I apply to real-life studies of cell motility on flat and nanostructured surfaces. These models aim to predict the time-dependent position of cell centroids in a stochastic manner, and conversely determine directly from experimental...

  5. Physical models of cell motility

    CERN Document Server

    2016-01-01

    This book surveys the most recent advances in physics-inspired cell movement models. This synergetic, cross-disciplinary effort to increase the fidelity of computational algorithms will lead to a better understanding of the complex biomechanics of cell movement, and stimulate progress in research on related active matter systems, from suspensions of bacteria and synthetic swimmers to cell tissues and cytoskeleton.Cell motility and collective motion are among the most important themes in biology and statistical physics of out-of-equilibrium systems, and crucial for morphogenesis, wound healing, and immune response in eukaryotic organisms. It is also relevant for the development of effective treatment strategies for diseases such as cancer, and for the design of bioactive surfaces for cell sorting and manipulation. Substrate-based cell motility is, however, a very complex process as regulatory pathways and physical force generation mechanisms are intertwined. To understand the interplay between adhesion, force ...

  6. Automated measurement of cell motility and proliferation

    Directory of Open Access Journals (Sweden)

    Goff Julie

    2005-04-01

    objects, and uncertainty in the outlining and positioning of cells by automated image analysis. Exponential growth, as monitored by total cell area, did not linearly correlate with absolute cell number, but proved valuable for selection of reliable tracking data and for disclosing between-experiment variations in cell growth. Conclusion These results demonstrate the applicability of a system that uses fully automated image acquisition and analysis to study cell motility and growth. Cellular motility response is determined in an unbiased and comparatively high throughput manner. Abundant ancillary data provide opportunities for uniform filtering according to criteria that select for biological relevance and for providing insight into features of system performance. Data quality measures have been developed that can serve as a basis for the design and quality control of experiments that are facilitated by automation and the 384 well plate format. This system is applicable to large-scale studies such as drug screening and research into effects of complex combinations of factors and matrices on cell phenotype.

  7. Active Gel Model of Amoeboid Cell Motility

    CERN Document Server

    Callan-Jones, A C

    2013-01-01

    We develop a model of amoeboid cell motility based on active gel theory. Modeling the motile apparatus of a eukaryotic cell as a confined layer of finite length of poroelastic active gel permeated by a solvent, we first show that, due to active stress and gel turnover, an initially static and homogeneous layer can undergo a contractile-type instability to a polarized moving state in which the rear is enriched in gel polymer. This agrees qualitatively with motile cells containing an actomyosin-rich uropod at their rear. We find that the gel layer settles into a steadily moving, inhomogeneous state at long times, sustained by a balance between contractility and filament turnover. In addition, our model predicts an optimal value of the gel-susbstrate adhesion leading to maximum layer speed, in agreement with cell motility assays. The model may be relevant to motility of cells translocating in complex, confining environments that can be mimicked experimentally by cell migration through microchannels.

  8. A Genome-wide RNAi Screen for Microtubule Bundle Formation and Lysosome Motility Regulation in Drosophila S2 Cells

    OpenAIRE

    Amber L. Jolly; Chi-Hao Luan; Brendon E. Dusel; Sara F. Dunne; Michael Winding; Vishrut J. Dixit; Chloe Robins; Jennifer L. Saluk; David J. Logan; Anne E. Carpenter; Manu Sharma; Deborah Dean; Andrew R. Cohen; Vladimir I. Gelfand

    2016-01-01

    Long-distance intracellular transport of organelles, mRNA, and proteins (“cargo”) occurs along the microtubule cytoskeleton by the action of kinesin and dynein motor proteins, but the vast network of factors involved in regulating intracellular cargo transport are still unknown. We capitalize on the Drosophila melanogaster S2 model cell system to monitor lysosome transport along microtubule bundles, which require enzymatically active kinesin-1 motor protein for their formation. We use an auto...

  9. A genome-wide RNAi screen for microtubule bundle formation and lysosome motility regulation in Drosophila S2 cells

    OpenAIRE

    Jolly, Amber L.; Luan, Chi-Hao; Dusel, Brendon E.; Dunne, Sara Fernandez; Winding, Michael; Dixit, Vishrut J.; Robins, Chloe; Saluk, Jennifer L.; Logan, David J.; Carpenter, Anne E.; Sharma, Manu; Dean, Deborah; Cohen, Andrew R.; Gelfand, Vladimir I.

    2016-01-01

    Long-distance intracellular transport of organelles, mRNA, and proteins (“cargo”) occurs along the microtubule cytoskeleton by the action of kinesin and dynein motor proteins; the vast network of factors involved in regulating intracellular cargo transport are still unknown. We capitalize on the Drosophila melanogaster S2 model cell system to monitor lysosome transport along microtubule bundles, which require enzymatically active kinesin-1 motor protein for their formation. We use an automate...

  10. Cell motility as random motion: A review

    DEFF Research Database (Denmark)

    Selmeczi, Dávid; Li, Liwen; Pedersen, Leif;

    2008-01-01

    The historical co-evolution of biological motility models with models of Brownian motion is outlined. Recent results for how to derive cell-type-specific motility models from experimental cell trajectories are reviewed. Experimental work in progress, which tests the generality of this...... phenomenological model building is reported. So is theoretical work in progress, which explains the characteristic time scales and correlations of phenomenological models in terms of the dynamics of cytoskeleton, lamellipodia, and pseudopodia....

  11. Hydrodynamic Contributions to Amoeboid Cell Motility

    Science.gov (United States)

    Lewis, Owen; Guy, Robert

    2012-11-01

    Understanding the methods by which cells move is a fundamental problem in modern biology. Recent evidence has shown that the fluid dynamics of cytoplasm can play a vital role in cellular motility. The slime mold Physarum polycephalum provides an excellent model organism for the study of amoeboid motion. In this research, we use a simply analytic model in conjuction with computational experiments to investigate intracellular fluid flow in a simple model of Physarum. Of particlar interest are stresses generated by cytoplasmic flow which may be used to aid in cellular motility. In our numerical model, the Immersed Boundary Method is used to account for such stresses. We investigate the relationship between contraction waves, flow waves, adhesion, and locomotive forces in an attempt to characterize conditions necessary to generate directed motion.

  12. Mechanics and polarity in cell motility

    Science.gov (United States)

    Ambrosi, D.; Zanzottera, A.

    2016-09-01

    The motility of a fish keratocyte on a flat substrate exhibits two distinct regimes: the non-migrating and the migrating one. In both configurations the shape is fixed in time and, when the cell is moving, the velocity is constant in magnitude and direction. Transition from a stable configuration to the other one can be produced by a mechanical or chemotactic perturbation. In order to point out the mechanical nature of such a bistable behaviour, we focus on the actin dynamics inside the cell using a minimal mathematical model. While the protein diffusion, recruitment and segregation govern the polarization process, we show that the free actin mass balance, driven by diffusion, and the polymerized actin retrograde flow, regulated by the active stress, are sufficient ingredients to account for the motile bistability. The length and velocity of the cell are predicted on the basis of the parameters of the substrate and of the cell itself. The key physical ingredient of the theory is the exchange among actin phases at the edges of the cell, that plays a central role both in kinematics and in dynamics.

  13. Colony Expansion of Socially Motile Myxococcus xanthus Cells Is Driven by Growth, Motility, and Exopolysaccharide Production.

    Science.gov (United States)

    Patra, Pintu; Kissoon, Kimberley; Cornejo, Isabel; Kaplan, Heidi B; Igoshin, Oleg A

    2016-06-01

    Myxococcus xanthus, a model organism for studies of multicellular behavior in bacteria, moves exclusively on solid surfaces using two distinct but coordinated motility mechanisms. One of these, social (S) motility is powered by the extension and retraction of type IV pili and requires the presence of exopolysaccharides (EPS) produced by neighboring cells. As a result, S motility requires close cell-to-cell proximity and isolated cells do not translocate. Previous studies measuring S motility by observing the colony expansion of cells deposited on agar have shown that the expansion rate increases with initial cell density, but the biophysical mechanisms involved remain largely unknown. To understand the dynamics of S motility-driven colony expansion, we developed a reaction-diffusion model describing the effects of cell density, EPS deposition and nutrient exposure on the expansion rate. Our results show that at steady state the population expands as a traveling wave with a speed determined by the interplay of cell motility and growth, a well-known characteristic of Fisher's equation. The model explains the density-dependence of the colony expansion by demonstrating the presence of a lag phase-a transient period of very slow expansion with a duration dependent on the initial cell density. We propose that at a low initial density, more time is required for the cells to accumulate enough EPS to activate S-motility resulting in a longer lag period. Furthermore, our model makes the novel prediction that following the lag phase the population expands at a constant rate independent of the cell density. These predictions were confirmed by S motility experiments capturing long-term expansion dynamics.

  14. Screening and identification of proteins mediating senna induced gastrointestinal motility enhancement in mouse colon

    Institute of Scientific and Technical Information of China (English)

    Xin Wang; Bo-Rong Pan; Dai-Min Fan; Yue-Xia Zhong; Mei Lan; Zong-You Zhang; Yong-Quan Shi; Ju Lu; Jie Ding; Kai-Cun Wu; Jian-Ping Jin

    2002-01-01

    .CONCLUSION: SE causes diarrhea and enhancesgastrointestinal motility through digestive tractadministration. Long-term gastric administration of SEinduces inflammatory changes and cell damage in the wholegastrointestinal tract. The differential proteins screened fromthe colonic tissues of the model mice might mediate theenhancing effect of SE on gastrointestinal motility.

  15. Cell motility as persistent random motion: Theories from experiments

    DEFF Research Database (Denmark)

    Selmeczi, D.; Mosler, S.; Hagedorn, P.H.;

    2005-01-01

    Experimental time series for trajectories of motile cells may contain so much information that a systematic analysis will yield cell-type- specific motility models. Here we demonstrate how, using human keratinocytes and fibroblasts as examples. The two resulting models reflect the cells' differen...

  16. Coordination of glioblastoma cell motility by PKCι

    Directory of Open Access Journals (Sweden)

    Baldwin R Mitchell

    2010-09-01

    Full Text Available Abstract Background Glioblastoma is one of the deadliest forms of cancer, in part because of its highly invasive nature. The tumor suppressor PTEN is frequently mutated in glioblastoma and is known to contribute to the invasive phenotype. However the downstream events that promote invasion are not fully understood. PTEN loss leads to activation of the atypical protein kinase C, PKCι. We have previously shown that PKCι is required for glioblastoma cell invasion, primarily by enhancing cell motility. Here we have used time-lapse videomicroscopy to more precisely define the role of PKCι in glioblastoma. Results Glioblastoma cells in which PKCι was either depleted by shRNA or inhibited pharmacologically were unable to coordinate the formation of a single leading edge lamellipod. Instead, some cells generated multiple small, short-lived protrusions while others generated a diffuse leading edge that formed around the entire circumference of the cell. Confocal microscopy showed that this behavior was associated with altered behavior of the cytoskeletal protein Lgl, which is known to be inactivated by PKCι phosphorylation. Lgl in control cells localized to the lamellipod leading edge and did not associate with its binding partner non-muscle myosin II, consistent with it being in an inactive state. In PKCι-depleted cells, Lgl was concentrated at multiple sites at the periphery of the cell and remained in association with non-muscle myosin II. Videomicroscopy also identified a novel role for PKCι in the cell cycle. Cells in which PKCι was either depleted by shRNA or inhibited pharmacologically entered mitosis normally, but showed marked delays in completing mitosis. Conclusions PKCι promotes glioblastoma motility by coordinating the formation of a single leading edge lamellipod and has a role in remodeling the cytoskeleton at the lamellipod leading edge, promoting the dissociation of Lgl from non-muscle myosin II. In addition PKCι is required

  17. Lichen Secondary Metabolite, Physciosporin, Inhibits Lung Cancer Cell Motility.

    Science.gov (United States)

    Yang, Yi; Park, So-Yeon; Nguyen, Thanh Thi; Yu, Young Hyun; Nguyen, Tru Van; Sun, Eun Gene; Udeni, Jayalal; Jeong, Min-Hye; Pereira, Iris; Moon, Cheol; Ha, Hyung-Ho; Kim, Kyung Keun; Hur, Jae-Seoun; Kim, Hangun

    2015-01-01

    Lichens produce various unique chemicals that can be used for pharmaceutical purposes. To screen for novel lichen secondary metabolites showing inhibitory activity against lung cancer cell motility, we tested acetone extracts of 13 lichen samples collected in Chile. Physciosporin, isolated from Pseudocyphellaria coriacea (Hook f. & Taylor) D.J. Galloway & P. James, was identified as an effective compound and showed significant inhibitory activity in migration and invasion assays against human lung cancer cells. Physciosporin treatment reduced both protein and mRNA levels of N-cadherin with concomitant decreases in the levels of epithelial-mesenchymal transition markers such as snail and twist. Physciosporin also suppressed KITENIN (KAI1 C-terminal interacting tetraspanin)-mediated AP-1 activity in both the absence and presence of epidermal growth factor stimulation. Quantitative real-time PCR analysis showed that the expression of the metastasis suppressor gene, KAI1, was increased while that of the metastasis enhancer gene, KITENIN, was dramatically decreased by physciosporin. Particularly, the activity of 3'-untranslated region of KITENIN was decreased by physciosporin. Moreover, Cdc42 and Rac1 activities were decreased by physciosporin. These results demonstrated that the lichen secondary metabolite, physciosporin, inhibits lung cancer cell motility through novel mechanisms of action. PMID:26371759

  18. Lichen Secondary Metabolite, Physciosporin, Inhibits Lung Cancer Cell Motility.

    Directory of Open Access Journals (Sweden)

    Yi Yang

    Full Text Available Lichens produce various unique chemicals that can be used for pharmaceutical purposes. To screen for novel lichen secondary metabolites showing inhibitory activity against lung cancer cell motility, we tested acetone extracts of 13 lichen samples collected in Chile. Physciosporin, isolated from Pseudocyphellaria coriacea (Hook f. & Taylor D.J. Galloway & P. James, was identified as an effective compound and showed significant inhibitory activity in migration and invasion assays against human lung cancer cells. Physciosporin treatment reduced both protein and mRNA levels of N-cadherin with concomitant decreases in the levels of epithelial-mesenchymal transition markers such as snail and twist. Physciosporin also suppressed KITENIN (KAI1 C-terminal interacting tetraspanin-mediated AP-1 activity in both the absence and presence of epidermal growth factor stimulation. Quantitative real-time PCR analysis showed that the expression of the metastasis suppressor gene, KAI1, was increased while that of the metastasis enhancer gene, KITENIN, was dramatically decreased by physciosporin. Particularly, the activity of 3'-untranslated region of KITENIN was decreased by physciosporin. Moreover, Cdc42 and Rac1 activities were decreased by physciosporin. These results demonstrated that the lichen secondary metabolite, physciosporin, inhibits lung cancer cell motility through novel mechanisms of action.

  19. Radiation-induced motility alterations in medulloblastoma cells

    OpenAIRE

    Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Klaus J. Weber; Debus, Jürgen; Combs, Stephanie E

    2015-01-01

    Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially radiation-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metallop...

  20. Rac and Rho GTPases in cancer cell motility control

    Directory of Open Access Journals (Sweden)

    Parri Matteo

    2010-09-01

    Full Text Available Abstract Rho GTPases represent a family of small GTP-binding proteins involved in cell cytoskeleton organization, migration, transcription, and proliferation. A common theme of these processes is a dynamic reorganization of actin cytoskeleton which has now emerged as a major switch control mainly carried out by Rho and Rac GTPase subfamilies, playing an acknowledged role in adaptation of cell motility to the microenvironment. Cells exhibit three distinct modes of migration when invading the 3 D environment. Collective motility leads to movement of cohorts of cells which maintain the adherens junctions and move by photolytic degradation of matrix barriers. Single cell mesenchymal-type movement is characterized by an elongated cellular shape and again requires extracellular proteolysis and integrin engagement. In addition it depends on Rac1-mediated cell polarization and lamellipodia formation. Conversely, in amoeboid movement cells have a rounded morphology, the movement is independent from proteases but requires high Rho GTPase to drive elevated levels of actomyosin contractility. These two modes of cell movement are interconvertible and several moving cells, including tumor cells, show an high degree of plasticity in motility styles shifting ad hoc between mesenchymal or amoeboid movements. This review will focus on the role of Rac and Rho small GTPases in cell motility and in the complex relationship driving the reciprocal control between Rac and Rho granting for the opportunistic motile behaviour of aggressive cancer cells. In addition we analyse the role of these GTPases in cancer progression and metastatic dissemination.

  1. Single cell motility and trail formation in populations of microglia

    Science.gov (United States)

    Lee, Kyoung Jin

    2009-03-01

    Microglia are a special type of glia cell in brain that has immune responses. They constitute about 20 % of the total glia population within the brain. Compared to other glia cells, microglia are very motile, constantly moving to destroy pathogens and to remove dead neurons. While doing so, they exhibit interesting body shapes, have cell-to-cell communications, and have chemotatic responses to each other. Interestingly, our recent in vitro studies show that their unusual motile behaviors can self-organize to form trails, similar to those in populations of ants. We have studied the changes in the physical properties of these trails by varying the cell population density and by changing the degree of spatial inhomogeneities (``pathogens''). Our experimental observations can be quite faithfully reproduced by a simple mathematical model involving many motile cells whose mechanical motion are driven by actin polymerization and depolymerization process within the individual cell body and by external chemical gradients.

  2. Helical motion of the cell body enhances Caulobacter crescentus motility.

    Science.gov (United States)

    Liu, Bin; Gulino, Marco; Morse, Michael; Tang, Jay X; Powers, Thomas R; Breuer, Kenneth S

    2014-08-01

    We resolve the 3D trajectory and the orientation of individual cells for extended times, using a digital tracking technique combined with 3D reconstructions. We have used this technique to study the motility of the uniflagellated bacterium Caulobacter crescentus and have found that each cell displays two distinct modes of motility, depending on the sense of rotation of the flagellar motor. In the forward mode, when the flagellum pushes the cell, the cell body is tilted with respect to the direction of motion, and it precesses, tracing out a helical trajectory. In the reverse mode, when the flagellum pulls the cell, the precession is smaller and the cell has a lower translation distance per rotation period and thus a lower motility. Using resistive force theory, we show how the helical motion of the cell body generates thrust and can explain the direction-dependent changes in swimming motility. The source of the cell body precession is believed to be associated with the flexibility of the hook that connects the flagellum to the cell body.

  3. HES6 enhances the motility of alveolar rhabdomyosarcoma cells

    International Nuclear Information System (INIS)

    Absract: HES6, a member of the hairy-enhancer-of-split family of transcription factors, plays multiple roles in myogenesis. It is a direct target of the myogenic transcription factor MyoD and has been shown to regulate the formation of the myotome in development, myoblast cell cycle exit and the organization of the actin cytoskeleton during terminal differentiation. Here we investigate the expression and function of HES6 in rhabdomyosarcoma, a soft tissue tumor which expresses myogenic genes but fails to differentiate into muscle. We show that HES6 is expressed at high levels in the subset of alveolar rhabdomyosarcomas expressing PAX/FOXO1 fusion genes (ARMSp). Knockdown of HES6 mRNA in the ARMSp cell line RH30 reduces proliferation and cell motility. This phenotype is rescued by expression of mouse Hes6 which is insensitive to HES6 siRNA. Furthermore, expression microarray analysis indicates that the HES6 knockdown is associated with a decrease in the levels of Transgelin, (TAGLN), a regulator of the actin cytoskeleton. Knockdown of TAGLN decreases cell motility, whilst TAGLN overexpression rescues the motility defect resulting from HES6 knockdown. These findings indicate HES6 contributes to the pathogenesis of ARMSp by enhancing both proliferation and cell motility.

  4. Radiation-induced motility alterations in medulloblastoma cells.

    Science.gov (United States)

    Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Weber, Klaus J; Debus, Jürgen; Combs, Stephanie E

    2015-05-01

    Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially radiation-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metalloproteinase concentrations within cell culture supernatants were investigated by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using Student's t-test. Both photon and carbon ion irradiation significantly reduced chemotactic medulloblastoma cell transmigration through 8-μm pore size membranes, while simultaneously increasing adherence to fibronectin- and collagen I- and IV-coated surfaces. Correspondingly, both photon and carbon ion irradiation downregulate soluble MMP9 concentrations, while upregulating cell surface expression of proadhesive extracellular matrix protein-binding integrin α5. The observed phenotype of radiation-altered motility is more pronounced following carbon ion than photon irradiation. Both photon and (even more so) carbon ion irradiation are effective in inhibiting medulloblastoma cell migration through downregulation of matrix metalloproteinase 9 and upregulation of proadhesive cell surface integrin α5, which lead to increased cell adherence to extracellular matrix proteins. PMID:25736470

  5. Inhibitory Activity of (+-Usnic Acid against Non-Small Cell Lung Cancer Cell Motility.

    Directory of Open Access Journals (Sweden)

    Yi Yang

    Full Text Available Lichens are symbiotic organisms that produce various unique chemicals that can be used for pharmaceutical purposes. With the aim of screening new anti-cancer agents that inhibit cancer cell motility, we tested the inhibitory activity of seven lichen species collected from the Romanian Carpathian Mountains against migration and invasion of human lung cancer cells and further investigated the molecular mechanisms underlying their anti-metastatic activity. Among them, Alectoria samentosa, Flavocetraria nivalis, Alectoria ochroleuca, and Usnea florida showed significant inhibitory activity against motility of human lung cancer cells. HPLC results showed that usnic acid is the main compound in these lichens, and (+-usnic acid showed similar inhibitory activity that crude extract have. Mechanistically, β-catenin-mediated TOPFLASH activity and KITENIN-mediated AP-1 activity were decreased by (+-usnic acid treatment in a dose-dependent manner. The quantitative real-time PCR data showed that (+-usnic acid decreased the mRNA level of CD44, Cyclin D1 and c-myc, which are the downstream target genes of both β-catenin/LEF and c-jun/AP-1. Also, Rac1 and RhoA activities were decreased by treatment with (+-usnic acid. Interestingly, higher inhibitory activity for cell invasion was observed when cells were treated with (+-usnic acid and cetuximab. These results implied that (+-usnic acid might have potential activity in inhibition of cancer cell metastasis, and (+-usnic acid could be used for anti-cancer therapy with a distinct mechanisms of action.

  6. Endothelial cell motility, coordination and pattern formation during vasculogenesis.

    Science.gov (United States)

    Czirok, Andras

    2013-01-01

    How vascular networks assemble is a fundamental problem of developmental biology that also has medical importance. To explain the organizational principles behind vascular patterning, we must understand how can tissue level structures be controlled through cell behavior patterns like motility and adhesion that, in turn, are determined by biochemical signal transduction processes? We discuss the various ideas that have been proposed as mechanisms for vascular network assembly: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and multicellular sprouting guided by cell-cell contacts. All of these processes yield emergent patterns, thus endothelial cells can form an interconnected structure autonomously, without guidance from an external pre-pattern.

  7. Optical Investigations of Endothelial Cell Motility

    DEFF Research Database (Denmark)

    Rossen, Ninna Struck

    A monolayer of endothelial cells lines the entire circulatory system and create a barrier between the circulatory system and the tissues. To create and maintain an intact barrier, the individual cells have to connect tightly with their neighbors, which causes a highly correlated motion between...

  8. The influence of electric field and confinement on cell motility.

    Directory of Open Access Journals (Sweden)

    Yu-Ja Huang

    Full Text Available The ability of cells to sense and respond to endogenous electric fields is important in processes such as wound healing, development, and nerve regeneration. In cell culture, many epithelial and endothelial cell types respond to an electric field of magnitude similar to endogenous electric fields by moving preferentially either parallel or antiparallel to the field vector, a process known as galvanotaxis. Here we report on the influence of dc electric field and confinement on the motility of fibroblast cells using a chip-based platform. From analysis of cell paths we show that the influence of electric field on motility is much more complex than simply imposing a directional bias towards the cathode or anode. The cell velocity, directedness, as well as the parallel and perpendicular components of the segments along the cell path are dependent on the magnitude of the electric field. Forces in the directions perpendicular and parallel to the electric field are in competition with one another in a voltage-dependent manner, which ultimately govern the trajectories of the cells in the presence of an electric field. To further investigate the effects of cell reorientation in the presence of a field, cells are confined within microchannels to physically prohibit the alignment seen in 2D environment. Interestingly, we found that confinement results in an increase in cell velocity both in the absence and presence of an electric field compared to migration in 2D.

  9. The influence of electric field and confinement on cell motility.

    Science.gov (United States)

    Huang, Yu-Ja; Samorajski, Justin; Kreimer, Rachel; Searson, Peter C

    2013-01-01

    The ability of cells to sense and respond to endogenous electric fields is important in processes such as wound healing, development, and nerve regeneration. In cell culture, many epithelial and endothelial cell types respond to an electric field of magnitude similar to endogenous electric fields by moving preferentially either parallel or antiparallel to the field vector, a process known as galvanotaxis. Here we report on the influence of dc electric field and confinement on the motility of fibroblast cells using a chip-based platform. From analysis of cell paths we show that the influence of electric field on motility is much more complex than simply imposing a directional bias towards the cathode or anode. The cell velocity, directedness, as well as the parallel and perpendicular components of the segments along the cell path are dependent on the magnitude of the electric field. Forces in the directions perpendicular and parallel to the electric field are in competition with one another in a voltage-dependent manner, which ultimately govern the trajectories of the cells in the presence of an electric field. To further investigate the effects of cell reorientation in the presence of a field, cells are confined within microchannels to physically prohibit the alignment seen in 2D environment. Interestingly, we found that confinement results in an increase in cell velocity both in the absence and presence of an electric field compared to migration in 2D.

  10. Control of exoenzyme production, motility and cell differentiation in Serratia liquefaciens

    DEFF Research Database (Denmark)

    Givskov, Michael Christian; Eberl, Leo; Molin, Søren

    1997-01-01

    Serratia liquefaciens secretes a broad spectrum of hydrolytic enzymes to the surrounding medium and possesses the ability to differentiate into specialized swarmer cells capable of rapid surface motility. Control of exoenzyme production and swarming motility is governed by similar regulatory...

  11. Membrane tension and cytoskeleton organization in cell motility

    International Nuclear Information System (INIS)

    Cell membrane shape changes are important for many aspects of normal biological function, such as tissue development, wound healing and cell division and motility. Various disease states are associated with deregulation of how cells move and change shape, including notably tumor initiation and cancer cell metastasis. Cell motility is powered, in large part, by the controlled assembly and disassembly of the actin cytoskeleton. Much of this dynamic happens in close proximity to the plasma membrane due to the fact that actin assembly factors are membrane-bound, and thus actin filaments are generally oriented such that their growth occurs against or near the membrane. For a long time, the membrane was viewed as a relatively passive scaffold for signaling. However, results from the last five years show that this is not the whole picture, and that the dynamics of the actin cytoskeleton are intimately linked to the mechanics of the cell membrane. In this review, we summarize recent findings concerning the role of plasma membrane mechanics in cell cytoskeleton dynamics and architecture, showing that the cell membrane is not just an envelope or a barrier for actin assembly, but is a master regulator controlling cytoskeleton dynamics and cell polarity. (topical review)

  12. Geometric determinants of directional cell motility revealed using microcontact printing.

    Science.gov (United States)

    Brock, Amy; Chang, Eric; Ho, Chia-Chi; LeDuc, Philip; Jiang, Xingyu; Whitesides, George M; Ingber, Donald E

    2003-03-01

    Mammalian cells redirect their movement in response to changes in the physical properties of their extracellular matrix (ECM) adhesive scaffolds, including changes in available substrate area, shape, or flexibility. Yet, little is known about the cell's ability to discriminate between different types of spatial signals. Here we utilize a soft-lithography-based, microcontact printing technology in combination with automated computerized image analysis to explore the relationship between ECM geometry and directional motility. When fibroblast cells were cultured on fibronectin-coated adhesive islands with the same area (900 micrometers2) but different geometric forms (square, triangle, pentagon, hexagon, trapezoid, various parallelograms) and aspect ratios, cells preferentially extended new lamellipodia from their corners. In addition, by imposing these simple geometric constraints through ECM, cells were directed to deposit new fibronectin fibrils in these same corner regions. These data indicate that mammalian cells can sense edges within ECM patterns that exhibit a wide range of angularity and that they use these spatial cues to guide where they will deposit ECM and extend new motile processes during the process of directional migration. PMID:14674434

  13. A kinetic mechanism for cell sorting based on local variations in cell motility

    Science.gov (United States)

    Strandkvist, Charlotte; Juul, Jeppe; Baum, Buzz; Kabla, Alexandre J.; Duke, Tom

    2014-01-01

    Our current understanding of cell sorting relies on physical difference, either in the interfacial properties or motile force, between cell types. But is such asymmetry a prerequisite for cell sorting? We test this using a minimal model in which the two cell populations are identical with respect to their physical properties and differences in motility arise solely from how cells interact with their surroundings. The model resembles the Schelling model used in social sciences to study segregation phenomena at the scale of societies. Our results demonstrate that segregation can emerge solely from cell motility being a dynamic property that changes in response to the local environment of the cell, but that additional mechanisms are necessary to reproduce the envelopment behaviour observed in vitro. The time course of segregation follows a power law, in agreement with the scaling reported from experiment and in other models of motility-driven segregation. PMID:25485079

  14. The contribution of cell-cell signaling and motility to bacterial biofilm formation

    DEFF Research Database (Denmark)

    Shrout, Joshua D; Tolker-Nielsen, Tim; Givskov, Michael;

    2011-01-01

    Many bacteria grow attached to a surface as biofilms. Several factors dictate biofilm formation, including responses by the colonizing bacteria to their environment. Here we review how bacteria use cell-cell signaling (also called quorum sensing) and motility during biofilm formation. Specifically...... gene expression important to the production of polysaccharides, rhamnolipid, and other virulence factors. Surface motility affects the assembly and architecture of biofilms, and some aspects of motility are also influenced by quorum sensing. While some genes and their function are specific to P....... aeruginosa, many aspects of biofilm development can be used as a model system to understand how bacteria differentially colonize surfaces....

  15. Role of extracellular cations in cell motility, polarity, and chemotaxis

    Directory of Open Access Journals (Sweden)

    Soll D

    2011-04-01

    Full Text Available David R Soll1, Deborah Wessels1, Daniel F Lusche1, Spencer Kuhl1, Amanda Scherer1, Shawna Grimm1,21Monoclonal Antibody Research Institute, Developmental Studies, Hybridoma Bank, Department of Biology, University of Iowa, Iowa City; 2Mercy Medical Center, Surgical Residency Program, Des Moines, Iowa, USAAbstract: The concentration of cations in the aqueous environment of free living organisms and cells within the human body influence motility, shape, and chemotaxis. The role of extracellular cations is usually perceived to be the source for intracellular cations in the process of homeostasis. The role of surface molecules that interact with extracellular cations is believed to be that of channels, transporters, and exchangers. However, the role of Ca2+ as a signal and chemoattractant and the discovery of the Ca2+ receptor have demonstrated that extracellular cations can function as signals at the cell surface, and the plasma membrane molecules they interact with can function as bona fide receptors that activate coupled signal transduction pathways, associated molecules in the plasma membrane, or the cytoskeleton. With this perspective in mind, we have reviewed the cationic composition of aqueous environments of free living cells and cells that move in multicellular organisms, most notably humans, the range of molecules interacting with cations at the cell surface, the concept of a cell surface cation receptor, and the roles extracellular cations and plasma membrane proteins that interact with them play in the regulation of motility, shape, and chemotaxis. Hopefully, the perspective of this review will increase awareness of the roles extracellular cations play and the possibility that many of the plasma membrane proteins that interact with them could also play roles as receptors.Keywords: extracellular cations, chemotaxis, transporters, calcium, receptors

  16. Motile apparatus in Vallisneria leaf cells. I. Organization of microfilaments.

    Science.gov (United States)

    Yamaguchi, Y; Nagai, R

    1981-04-01

    The organization of the microfilaments in epidermal cells of Vallisneria leaves was investigated with respect to the induction of cytoplasmic streaming (secondary streaming). In many of the epidermal cells, cytoplasm exhibited rotational streaming along the anticlinal wall of the cell after exposure around the anticlinal wall. The bundles were arrayed in parallel to the streaming direction. They were recognized usually as 10-40 closely packed dense dots in cross-section. The spacing between bundles was not even. Bundles tended to form groups of 4 to 5 in which the spacing between bundles was usually 0.3 to 0.5 micrometer. The microfilaments were identified as F-actin. Together with the fact that rotational streaming in Vallisneria cells by cytochalasin B, the motile mechanism of secondary streaming was concluded to be similar in its essential features to the cytoplasmic streaming seen in Characean cell (primary streaming). In epidermal cells that had been kept under low-intensity light the cytoplasm and the cytoplasmic streaming occurred in these cells. The bundles of microfilaments remained in the very thin layer of cytoplasm lining the anticlinal wall, although they were fewer and somewhat loosely packed. EGTA at appropriate concentration could induce cytoplasmic streaming in these cells. The mechanism of the induction is discussed on the basis of the effectiveness of EGTA and the requirement of a low concentration of free Ca2+ for cytoplasmic streaming in Characean cells. PMID:6792210

  17. The interplay between cell motility and tissue architecture

    Science.gov (United States)

    Tanner, Kandice

    2013-03-01

    Glandular tissue form arboreal networks comprised of acini and tubes. Loss of structure is concomitant with the in vivo pathologic state. In vitro models have been shown to recapitulate the functional units of the mammary gland and other organs. Despite our much improved understanding gleaned from both in vitro and in vivo interrogation, the mechanisms by which cells are able to achieve the correct tissue organization remain elusive. How do single mammary epithelial cells form polarized acini when cultured in a surrogate basement membrane gel but not on 2D surfaces? Simply put, how does a cell know which way is up? Why do malignant breast cells show a differential response in that they form non-polarized aggregates? Recently, it was determined that non-malignant cells undergo multiple rotations to establish acini while tumor cells are randomly motile during tumor formation. Can it be that a tumor cell has simply lost its way. This research was supported by the Intramural Research Program of the NIH, National Cancer Institute.

  18. Cell motility, morphology, viability and proliferation in response to nanotopography on silicon black

    DEFF Research Database (Denmark)

    Lopacinska, Joanna M.; Gradinaru, Cristian; Wierzbicki, Rafal;

    2012-01-01

    viability and proliferation show little dependence on substrate type. We conclude that motility analysis can show a wide range of cell responses e. g. over a factor of two in cell speed to different nano-topographies, where standard assays, such as viability or proliferation, in the tested cases show much...... standard measurements of cell viability, proliferation, and morphology on various surfaces. We also analyzed the motility of cells on the same surfaces, as recorded in time lapse movies of sparsely populated cell cultures. We find that motility and morphology vary strongly with nano-patterns, while...

  19. In vitro cell motility as a potential mesenchymal stem cell marker for multipotency.

    Science.gov (United States)

    Bertolo, Alessandro; Gemperli, Armin; Gruber, Marco; Gantenbein, Benjamin; Baur, Martin; Pötzel, Tobias; Stoyanov, Jivko

    2015-01-01

    Mesenchymal stem cells (MSCs) are expected to have a fundamental role in future cell-based therapies because of their high proliferative ability, multilineage potential, and immunomodulatory properties. Autologous transplantations have the "elephant in the room" problem of wide donor variability, reflected by variability in MSC quality and characteristics, leading to uncertain outcomes in the use of these cells. We propose life imaging as a tool to characterize populations of human MSCs. Bone marrow MSCs from various donors and in vitro passages were evaluated for their in vitro motility, and the distances were correlated to the adipogenic, chondrogenic, and osteogenic differentiation potentials and the levels of senescence and cell size. Using life-image measuring of track lengths of 70 cells per population for a period of 24 hours, we observed that slow-moving cells had the higher proportion of senescent cells compared with fast ones. Larger cells moved less than smaller ones, and spindle-shaped cells had an average speed. Both fast cells and slow cells were characterized by a low differentiation potential, and average-moving cells were more effective in undergoing all three lineage differentiations. Furthermore, heterogeneity in single cell motility within a population correlated with the average-moving cells, and fast- and slow-moving cells tended toward homogeneity (i.e., a monotonous moving pattern). In conclusion, in vitro cell motility might be a useful tool to quickly characterize and distinguish the MSC population's differentiation potential before additional use. PMID:25473086

  20. Influence of Helical Cell Shape on Motility of Helicobacter Pylori

    Science.gov (United States)

    Hardcastle, Joseph; Martinez, Laura; Salama, Nina; Bansil, Rama; Boston University Collaboration; University of Washington Collaboration

    2014-03-01

    Bacteria's body shape plays an important role in motility by effecting chemotaxis, swimming mechanisms, and swimming speed. A prime example of this is the bacteria Helicobacter Pylori;whose helical shape has long been believed to provide an advantage in penetrating the viscous mucus layer protecting the stomach lining, its niche environment. To explore this we have performed bacteria tracking experiments of both wild-type bacteria along with mutants, which have a straight rod shape. A wide distribution of speeds was found. This distribution reflects both a result of temporal variation in speed and different shape morphologies in the bacterial population. Our results show that body shape plays less role in a simple fluid. However, in a more viscous solution the helical shape results in increased swimming speeds. In addition, we use experimentally obtained cell shape measurements to model the hydrodynamic influence of cell shape on swimming speed using resistive force theory. The results agree with the experiment, especially when we fold in the temporal distribution. Interestingly, our results suggest distinct wild-type subpopulations with varying number of half helices can lead to different swimming speeds. NSF PHY

  1. Multiple scale model for cell migration in monolayers: Elastic mismatch between cells enhances motility.

    Science.gov (United States)

    Palmieri, Benoit; Bresler, Yony; Wirtz, Denis; Grant, Martin

    2015-01-01

    We propose a multiscale model for monolayer of motile cells that comprise normal and cancer cells. In the model, the two types of cells have identical properties except for their elasticity; cancer cells are softer and normal cells are stiffer. The goal is to isolate the role of elasticity mismatch on the migration potential of cancer cells in the absence of other contributions that are present in real cells. The methodology is based on a phase-field description where each cell is modeled as a highly-deformable self-propelled droplet. We simulated two types of nearly confluent monolayers. One contains a single cancer cell in a layer of normal cells and the other contains normal cells only. The simulation results demonstrate that elasticity mismatch alone is sufficient to increase the motility of the cancer cell significantly. Further, the trajectory of the cancer cell is decorated by several speed "bursts" where the cancer cell quickly relaxes from a largely deformed shape and consequently increases its translational motion. The increased motility and the amplitude and frequency of the bursts are in qualitative agreement with recent experiments. PMID:26134134

  2. Intracellular Theileria annulata promote invasive cell motility through kinase regulation of the host actin cytoskeleton.

    Directory of Open Access Journals (Sweden)

    Min Ma

    2014-03-01

    Full Text Available The intracellular, protozoan Theileria species parasites are the only eukaryotes known to transform another eukaryotic cell. One consequence of this parasite-dependent transformation is the acquisition of motile and invasive properties of parasitized cells in vitro and their metastatic dissemination in the animal, which causes East Coast Fever (T. parva or Tropical Theileriosis (T. annulata. These motile and invasive properties of infected host cells are enabled by parasite-dependent, poorly understood F-actin dynamics that control host cell membrane protrusions. Herein, we dissected functional and structural alterations that cause acquired motility and invasiveness of T. annulata-infected cells, to understand the molecular basis driving cell dissemination in Tropical Theileriosis. We found that chronic induction of TNFα by the parasite contributes to motility and invasiveness of parasitized host cells. We show that TNFα does so by specifically targeting expression and function of the host proto-oncogenic ser/thr kinase MAP4K4. Blocking either TNFα secretion or MAP4K4 expression dampens the formation of polar, F-actin-rich invasion structures and impairs cell motility in 3D. We identified the F-actin binding ERM family proteins as MAP4K4 downstream effectors in this process because TNFα-induced ERM activation and cell invasiveness are sensitive to MAP4K4 depletion. MAP4K4 expression in infected cells is induced by TNFα-JNK signalling and maintained by the inhibition of translational repression, whereby both effects are parasite dependent. Thus, parasite-induced TNFα promotes invasive motility of infected cells through the activation of MAP4K4, an evolutionary conserved kinase that controls cytoskeleton dynamics and cell motility. Hence, MAP4K4 couples inflammatory signaling to morphodynamic processes and cell motility, a process exploited by the intracellular Theileria parasite to increase its host cell's dissemination capabilities.

  3. Individual cell motility studied by time-lapse video recording: influence of experimental conditions

    DEFF Research Database (Denmark)

    Hartmann-Petersen, R; Walmod, P S; Berezin, A;

    2000-01-01

    BACKGROUND: Eukaryotic cell motility plays a key role during development, wound healing, and tumour invasion. Computer-assisted image analysis now makes it a realistic task to quantify individual cell motility of a large number of cells. However, the influence of culture conditions before...... and during measurements has not been investigated systematically. METHODS: We have evaluated intraassay and interassay variations in determinations of cellular speed of fibroblastoid L929 cells and investigated the effects of a series of physical and biological parameters on the motile behavior of this cell...... line. Cellular morphology and organization of filamentous actin were assessed by means of phase-contrast and confocal laser scanning microscopy and compared to the corresponding motility data. RESULTS: Cell dissociation procedure, seeding density, time of cultivation, and substrate concentration were...

  4. A model for cell motility on soft bio-adhesive substrates.

    Science.gov (United States)

    Sarvestani, Alireza S

    2011-02-24

    Mechanical stiffness of bio-adhesive substrates has been recognized as a major regulator of cell motility. We present a simple physical model to study the crawling locomotion of a contractile cell on a soft elastic substrate. The mechanism of rigidity sensing is accounted for using Schwarz's two-spring model Schwarz et al. (2006). The predicted dependency between the speed of motility and substrate stiffness is qualitatively consistent with experimental observations. The model demonstrates that the rigidity dependent motility of cells is rooted in the regulation of actomyosin contractile forces by substrate deformation at each anchorage point. On stiffer substrates, the traction forces required for cell translocation acquire larger magnitude but show weaker asymmetry which leads to slower cell motility. On very soft substrates, the model predicts a biphasic relationship between the substrate rigidity and the speed of locomotion, over a narrow stiffness range, which has been observed experimentally for some cell types. PMID:21106198

  5. Ceramide limits phosphatidylinositol-3-kinase C2β-controlled cell motility in ovarian cancer: potential of ceramide as a metastasis-suppressor lipid.

    Science.gov (United States)

    Kitatani, K; Usui, T; Sriraman, S K; Toyoshima, M; Ishibashi, M; Shigeta, S; Nagase, S; Sakamoto, M; Ogiso, H; Okazaki, T; Hannun, Y A; Torchilin, V P; Yaegashi, N

    2016-05-01

    Targeting cell motility, which is required for dissemination and metastasis, has therapeutic potential for ovarian cancer metastasis, and regulatory mechanisms of cell motility need to be uncovered for developing novel therapeutics. Invasive ovarian cancer cells spontaneously formed protrusions, such as lamellipodia, which are required for generating locomotive force in cell motility. Short interfering RNA screening identified class II phosphatidylinositol 3-kinase C2β (PI3KC2β) as the predominant isoform of PI3K involved in lamellipodia formation of ovarian cancer cells. The bioactive sphingolipid ceramide has emerged as an antitumorigenic lipid, and treatment with short-chain C6-ceramide decreased the number of ovarian cancer cells with PI3KC2β-driven lamellipodia. Pharmacological analysis demonstrated that long-chain ceramide regenerated from C6-ceramide through the salvage/recycling pathway, at least in part, mediated the action of C6-ceramide. Mechanistically, ceramide was revealed to interact with the PIK-catalytic domain of PI3KC2β and affect its compartmentalization, thereby suppressing PI3KC2β activation and its driven cell motility. Ceramide treatment also suppressed cell motility promoted by epithelial growth factor, which is a prometastatic factor. To examine the role of ceramide in ovarian cancer metastasis, ceramide liposomes were employed and confirmed to suppress cell motility in vitro. Ceramide liposomes had an inhibitory effect on peritoneal metastasis in a murine xenograft model of human ovarian cancer. Metastasis of PI3KC2β knocked-down cells was insensitive to treatment with ceramide liposomes, suggesting specific involvement of ceramide interaction with PI3KC2β in metastasis suppression. Our study identified ceramide as a bioactive lipid that limits PI3KC2β-governed cell motility, and ceramide is proposed to serve as a metastasis-suppressor lipid in ovarian cancer. These findings could be translated into developing ceramide

  6. Rapamycin inhibits IGF-1 stimulated cell motility through PP2A pathway.

    Directory of Open Access Journals (Sweden)

    Lei Liu

    Full Text Available Serine/threonine (Ser/Thr protein phosphatase 2A (PP2A has been implicated as a novel component of the mammalian target of rapamycin (mTOR signaling pathway. Recently we have demonstrated that mTOR regulates cell motility in part through p70 S6 kinase 1 (S6K1 and eukaryotic initiation factor 4E (eIF4E binding protein 1 (4E-BP1 pathways. Little is known about the role of PP2A in the mTOR-mediated cell motility. Here we show that rapamycin inhibited the basal or insulin-like growth factor 1 (IGF-1-induced motility of human Ewing sarcoma (Rh1 and rhabdomyosarcoma (Rh30 cells. Treatment of the cells with rapamycin activated PP2A activity, and concurrently inhibited IGF-1 stimulated phosphorylation of Erk1/2. Inhibition of Erk1/2 with PD98059 did not significantly affect the basal mobility of the cells, but dramatically inhibited IGF-1-induced cell motility. Furthermore, inhibition of PP2A with okadaic acid significantly attenuated the inhibitory effect of rapamycin on IGF-1-stimulated phosphorylation of Erk1/2 as well as cell motility. Consistently, expression of dominant negative PP2A conferred resistance to IGF-1-stimulated phosphorylation of Erk1/2 and cell motility. Expression of constitutively active MKK1 also attenuated rapamycin inhibition of IGF-1-stimulated phosphorylation of Erk1/2 and cell motility. The results suggest that rapamycin inhibits cell motility, in part by targeting PP2A-Erk1/2 pathway.

  7. A Mathematical Model Quantifies Proliferation and Motility Effects of TGF-β on Cancer Cells

    Directory of Open Access Journals (Sweden)

    Shizhen Emily Wang

    2009-01-01

    Full Text Available Transforming growth factor (TGF-β is known to have properties of both a tumour suppressor and a tumour promoter. While it inhibits cell proliferation, it also increases cell motility and decreases cell–cell adhesion. Coupling mathematical modelling and experiments, we investigate the growth and motility of oncogene-expressing human mammary epithelial cells under exposure to TGF-β. We use a version of the well-known Fisher–Kolmogorov equation, and prescribe a procedure for its parametrisation. We quantify the simultaneous effects of TGF-β to increase the tendency of individual cells and cell clusters to move randomly and to decrease overall population growth. We demonstrate that in experiments with TGF-β treated cells in vitro, TGF-β increases cell motility by a factor of 2 and decreases cell proliferation by a factor of 1/2 in comparison with untreated cells.

  8. Swimming motility plays a key role in the stochastic dynamics of cell clumping

    Science.gov (United States)

    Qi, Xianghong; Nellas, Ricky B.; Byrn, Matthew W.; Russell, Matthew H.; Bible, Amber N.; Alexandre, Gladys; Shen, Tongye

    2013-04-01

    Dynamic cell-to-cell interactions are a prerequisite to many biological processes, including development and biofilm formation. Flagellum induced motility has been shown to modulate the initial cell-cell or cell-surface interaction and to contribute to the emergence of macroscopic patterns. While the role of swimming motility in surface colonization has been analyzed in some detail, a quantitative physical analysis of transient interactions between motile cells is lacking. We examined the Brownian dynamics of swimming cells in a crowded environment using a model of motorized adhesive tandem particles. Focusing on the motility and geometry of an exemplary motile bacterium Azospirillum brasilense, which is capable of transient cell-cell association (clumping), we constructed a physical model with proper parameters for the computer simulation of the clumping dynamics. By modulating mechanical interaction (‘stickiness’) between cells and swimming speed, we investigated how equilibrium and active features affect the clumping dynamics. We found that the modulation of active motion is required for the initial aggregation of cells to occur at a realistic time scale. Slowing down the rotation of flagellar motors (and thus swimming speeds) is correlated to the degree of clumping, which is consistent with the experimental results obtained for A. brasilense.

  9. Cyclin-dependent kinase 5 activity controls cell motility and metastatic potential of prostate cancer cells.

    Science.gov (United States)

    Strock, Christopher J; Park, Jong-In; Nakakura, Eric K; Bova, G Steven; Isaacs, John T; Ball, Douglas W; Nelkin, Barry D

    2006-08-01

    We show here that cyclin-dependent kinase 5 (CDK5), a known regulator of migration in neuronal development, plays an important role in prostate cancer motility and metastasis. P35, an activator of CDK5 that is indicative of its activity, is expressed in a panel of human and rat prostate cancer cell lines, and is also expressed in 87.5% of the human metastatic prostate cancers we examined. Blocking of CDK5 activity with a dominant-negative CDK5 construct, small interfering RNA, or roscovitine resulted in changes in the microtubule cytoskeleton, loss of cellular polarity, and loss of motility. Expression of a dominant-negative CDK5 in the highly metastatic Dunning AT6.3 prostate cancer cell line also greatly impaired invasive capacity. CDK5 activity was important for spontaneous metastasis in vivo; xenografts of AT6.3 cells expressing dominant-negative CDK5 had less than one-fourth the number of lung metastases exhibited by AT6.3 cells expressing the empty vector. These results show that CDK5 activity controls cell motility and metastatic potential in prostate cancer.

  10. Swimming motility plays a key role in the stochastic dynamics of cell clumping

    International Nuclear Information System (INIS)

    Dynamic cell-to-cell interactions are a prerequisite to many biological processes, including development and biofilm formation. Flagellum induced motility has been shown to modulate the initial cell–cell or cell–surface interaction and to contribute to the emergence of macroscopic patterns. While the role of swimming motility in surface colonization has been analyzed in some detail, a quantitative physical analysis of transient interactions between motile cells is lacking. We examined the Brownian dynamics of swimming cells in a crowded environment using a model of motorized adhesive tandem particles. Focusing on the motility and geometry of an exemplary motile bacterium Azospirillum brasilense, which is capable of transient cell–cell association (clumping), we constructed a physical model with proper parameters for the computer simulation of the clumping dynamics. By modulating mechanical interaction (‘stickiness’) between cells and swimming speed, we investigated how equilibrium and active features affect the clumping dynamics. We found that the modulation of active motion is required for the initial aggregation of cells to occur at a realistic time scale. Slowing down the rotation of flagellar motors (and thus swimming speeds) is correlated to the degree of clumping, which is consistent with the experimental results obtained for A. brasilense. (paper)

  11. Computer-assisted quantification of motile and invasive capabilities of cancer cells.

    Science.gov (United States)

    Kumar, Karthiga Santhana; Pillong, Max; Kunze, Jens; Burghardt, Isabel; Weller, Michael; Grotzer, Michael A; Schneider, Gisbert; Baumgartner, Martin

    2015-10-21

    High-throughput analysis of cancer cell dissemination and its control by extrinsic and intrinsic cellular factors is hampered by the lack of adequate and efficient analytical tools for quantifying cell motility. Oncology research would greatly benefit from such a methodology that allows to rapidly determine the motile behaviour of cancer cells under different environmental conditions, including inside three-dimensional matrices. We combined automated microscopy imaging of two- and three-dimensional cell cultures with computational image analysis into a single assay platform for studying cell dissemination in high-throughput. We have validated this new approach for medulloblastoma, a metastatic paediatric brain tumour, in combination with the activation of growth factor signalling pathways with established pro-migratory functions. The platform enabled the detection of primary tumour and patient-derived xenograft cell sensitivity to growth factor-dependent motility and dissemination and identified tumour subgroup-specific responses to selected growth factors of excellent diagnostic value.

  12. The influence of non polar and polar molecules in mouse motile cells membranes and pure lipid bilayers.

    Directory of Open Access Journals (Sweden)

    Francisco J Sierra-Valdez

    Full Text Available We report an experimental study of mouse sperm motility that shows chief aspects characteristic of neurons: the anesthetic (produced by tetracaine and excitatory (produced by either caffeine or calcium effects and their antagonic action. While tetracaine inhibits sperm motility and caffeine has an excitatory action, the combination of these two substances balance the effects, producing a motility quite similar to that of control cells. We also study the effects of these agents (anesthetic and excitatory on the melting points of pure lipid liposomes constituted by 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC and dipalmitoyl phosphatidic acid (DPPA. Tetracaine induces a large fluidization of the membrane, shifting the liposomes melting transition temperature to much lower values. The effect of caffeine is null, but its addition to tetracaine-doped liposomes greatly screen the fluidization effect. A high calcium concentration stiffens pure lipid membranes and strongly reduces the effect of tetracaine. Molecular Dynamics Simulations are performed to further understand our experimental findings at the molecular level. We find a strong correlation between the effect of antagonic molecules that could explain how the mechanical properties suitable for normal cell functioning are affected and recovered.

  13. Silencing GFAP isoforms in astrocytoma cells disturbs laminin-dependent motility and cell adhesion.

    Science.gov (United States)

    Moeton, Martina; Kanski, Regina; Stassen, Oscar M J A; Sluijs, Jacqueline A; Geerts, Dirk; van Tijn, Paula; Wiche, Gerhard; van Strien, Miriam E; Hol, Elly M

    2014-07-01

    Glial fibrillary acidic protein (GFAP) is an intermediate filament protein expressed in astrocytes and neural stem cells. The GFAP gene is alternatively spliced, and expression of GFAP is highly regulated during development, on brain damage, and in neurodegenerative diseases. GFAPα is the canonical splice variant and is expressed in all GFAP-positive cells. In the human brain, the alternatively spliced transcript GFAPδ marks specialized astrocyte populations, such as subpial astrocytes and the neurogenic astrocytes in the human subventricular zone. We here show that shifting the GFAP isoform ratio in favor of GFAPδ in astrocytoma cells, by selectively silencing the canonical isoform GFAPα with short hairpin RNAs, induced a change in integrins, a decrease in plectin, and an increase in expression of the extracellular matrix component laminin. Together, this did not affect cell proliferation but resulted in a significantly decreased motility of astrocytoma cells. In contrast, a down-regulation of all GFAP isoforms led to less cell spreading, increased integrin expression, and a >100-fold difference in the adhesion of astrocytoma cells to laminin. In summary, isoform-specific silencing of GFAP revealed distinct roles of a specialized GFAP network in regulating the interaction of astrocytoma cells with the extracellular matrix through laminin.-Moeton, M., Kanski, R., Stassen, O. M. J. A., Sluijs, J. A., Geerts, D., van Tijn, P., Wiche, G., van Strien, M. E., Hol, E. M. Silencing GFAP isoforms in astrocytoma cells disturbs laminin dependent motility and cell adhesion.

  14. Polarized cell motility induces hydrogen peroxide to inhibit cofilin via cysteine oxidation.

    Science.gov (United States)

    Cameron, Jenifer M; Gabrielsen, Mads; Chim, Ya Hua; Munro, June; McGhee, Ewan J; Sumpton, David; Eaton, Philip; Anderson, Kurt I; Yin, Huabing; Olson, Michael F

    2015-06-01

    Mesenchymal cell motility is driven by polarized actin polymerization [1]. Signals at the leading edge recruit actin polymerization machinery to promote membrane protrusion, while matrix adhesion generates tractive force to propel forward movement. To work effectively, cell motility is regulated by a complex network of signaling events that affect protein activity and localization. H2O2 has an important role as a diffusible second messenger [2], and mediates its effects through oxidation of cysteine thiols. One cell activity influenced by H2O2 is motility [3]. However, a lack of sensitive and H2O2-specific probes for measurements in live cells has not allowed for direct observation of H2O2 accumulation in migrating cells or protrusions. In addition, the identities of proteins oxidized by H2O2 that contribute to actin dynamics and cell motility have not been characterized. We now show, as determined by fluorescence lifetime imaging microscopy, that motile cells generate H2O2 at membranes and cell protrusions and that H2O2 inhibits cofilin activity through oxidation of cysteines 139 (C139) and 147 (C147). Molecular modeling suggests that C139 oxidation would sterically hinder actin association, while the increased negative charge of oxidized C147 would lead to electrostatic repulsion of the opposite negatively charged surface. Expression of oxidation-resistant cofilin impairs cell spreading, adhesion, and directional migration. These findings indicate that H2O2 production contributes to polarized cell motility through localized cofilin inhibition and that there are additional proteins oxidized during cell migration that might have similar roles.

  15. Interactions between MUC1 and p120 catenin regulate dynamic features of cell adhesion, motility and metastasis

    Science.gov (United States)

    Liu, Xiang; Yi, Chunhui; Wen, Yunfei; Radhakrishnan, Prakash; Tremayne, Jarrod R.; Dao, Thongtan; Johnson, Keith R.; Hollingsworth, Michael A.

    2014-01-01

    The mechanisms by which MUC1 and p120 catenin contribute to progression of cancers from early transformation to metastasis are poorly understood. Here we show that p120 catenin ARM domains 1, 3–5 and 8 mediate interactions between p120 catenin and MUC1, and that these interactions modulate dynamic properties of cell adhesion, motility and metastasis of pancreatic cancer cells. We also show that different isoforms of p120 catenin when co-expressed with MUC1 create cells that exhibit distinct patterns of motility in culture (motility independent of cell adhesion, motility within a monolayer while exchanging contacts with other cells, and unified motility while maintaining static epithelial contacts) and patterns of metastasis. The results provide new insight into the dynamic interplay between cell adhesion and motility and the relationship of these to the metastatic process. PMID:24371222

  16. Different Motile Behaviors of Human Hematopoietic Stem versus Progenitor Cells at the Osteoblastic Niche

    Directory of Open Access Journals (Sweden)

    Katie Foster

    2015-11-01

    Full Text Available Despite advances in our understanding of interactions between mouse hematopoietic stem cells (HSCs and their niche, little is known about communication between human HSCs and the microenvironment. Using a xenotransplantation model and intravital imaging, we demonstrate that human HSCs display distinct motile behaviors to their hematopoietic progenitor cell (HPC counterparts, and the same pattern can be found between mouse HSCs and HPCs. HSCs become significantly less motile after transplantation, while progenitor cells remain motile. We show that human HSCs take longer to find their niche than previously expected and suggest that the niche be defined as the position where HSCs stop moving. Intravital imaging is the only technique to determine where in the bone marrow stem cells stop moving, and future analyses should focus on the environment surrounding the HSC at this point.

  17. Suppressive effects of 3-bromopyruvate on the proliferation and the motility of hepatocellular carcinoma cells.

    Science.gov (United States)

    Tomizawa, Minoru; Shinozaki, Fuminobu; Motoyoshi, Yasufumi; Sugiyama, Takao; Yamamoto, Shigenori; Ishige, Naoki

    2016-01-01

    The compound 3-bromopyruvate (3BP) is an analogue of pyruvate, which is the final product of glycolysis that enters the citric acid cycle. The present study aimed to investigate the suppressive effects of 3BP on the proliferation and motility of hepatocellular carcinoma (HCC) cells. HLF and PLC/PRF/5 cells were cultured with 3BP and subjected to an MTS assay. Apoptosis was analyzed by hematoxylin and eosin staining. Cell motility was analyzed using a scratch assay. Real-time quantitative polymerase chain reaction (PCR) was performed to determine the expression levels of cyclin D1 and matrix metalloproteinase (MMP)9. Proliferation of both cell lines was significantly suppressed by 3BP at 100 µM (P<0.05). The expression level of cyclin D1 was decreased after 3BP treatment at 100 µM in both cell lines (P<0.05). Pyknotic nuclei were observed in the cells cultured with 3BP at 100 µM. These results revealed that 3BP suppressed cell proliferation, decreased the expression of cyclin D1, and induced apoptosis in HCC cells. 3BP significantly suppressed motility in both cell lines (P<0.05). The expression level of MMP9 was significantly decreased (P<0.05). 3BP suppressed the proliferation and motility of HCC cells by decreasing the expression of cyclin D1 and MMP9. PMID:26530887

  18. On-Chip Clonal Analysis of Glioma-Stem-Cell Motility and Therapy Resistance.

    Science.gov (United States)

    Gallego-Perez, Daniel; Chang, Lingqian; Shi, Junfeng; Ma, Junyu; Kim, Sung-Hak; Zhao, Xi; Malkoc, Veysi; Wang, Xinmei; Minata, Mutsuko; Kwak, Kwang J; Wu, Yun; Lafyatis, Gregory P; Lu, Wu; Hansford, Derek J; Nakano, Ichiro; Lee, L James

    2016-09-14

    Enhanced glioma-stem-cell (GSC) motility and therapy resistance are considered to play key roles in tumor cell dissemination and recurrence. As such, a better understanding of the mechanisms by which these cells disseminate and withstand therapy could lead to more efficacious treatments. Here, we introduce a novel micro-/nanotechnology-enabled chip platform for performing live-cell interrogation of patient-derived GSCs with single-clone resolution. On-chip analysis revealed marked intertumoral differences (>10-fold) in single-clone motility profiles between two populations of GSCs, which correlated well with results from tumor-xenograft experiments and gene-expression analyses. Further chip-based examination of the more-aggressive GSC population revealed pronounced interclonal variations in motility capabilities (up to ∼4-fold) as well as gene-expression profiles at the single-cell level. Chip-supported therapy resistance studies with a chemotherapeutic agent (i.e., temozolomide) and an oligo RNA (anti-miR363) revealed a subpopulation of CD44-high GSCs with strong antiapoptotic behavior as well as enhanced motility capabilities. The living-cell-interrogation chip platform described herein enables thorough and large-scale live monitoring of heterogeneous cancer-cell populations with single-cell resolution, which is not achievable by any other existing technology and thus has the potential to provide new insights into the cellular and molecular mechanisms modulating glioma-stem-cell dissemination and therapy resistance.

  19. A comparison of computational models for eukaryotic cell shape and motility.

    Directory of Open Access Journals (Sweden)

    William R Holmes

    Full Text Available Eukaryotic cell motility involves complex interactions of signalling molecules, cytoskeleton, cell membrane, and mechanics interacting in space and time. Collectively, these components are used by the cell to interpret and respond to external stimuli, leading to polarization, protrusion, adhesion formation, and myosin-facilitated retraction. When these processes are choreographed correctly, shape change and motility results. A wealth of experimental data have identified numerous molecular constituents involved in these processes, but the complexity of their interactions and spatial organization make this a challenging problem to understand. This has motivated theoretical and computational approaches with simplified caricatures of cell structure and behaviour, each aiming to gain better understanding of certain kinds of cells and/or repertoire of behaviour. Reaction-diffusion (RD equations as well as equations of viscoelastic flows have been used to describe the motility machinery. In this review, we describe some of the recent computational models for cell motility, concentrating on simulations of cell shape changes (mainly in two but also three dimensions. The problem is challenging not only due to the difficulty of abstracting and simplifying biological complexity but also because computing RD or fluid flow equations in deforming regions, known as a "free-boundary" problem, is an extremely challenging problem in applied mathematics. Here we describe the distinct approaches, comparing their strengths and weaknesses, and the kinds of biological questions that they have been able to address.

  20. Identifying the common interaction networks of amoeboid motility and cancer cell metastasis

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    Ahmed H. Zeitoun

    2012-06-01

    Full Text Available The recently analyzed genome of Naegleria gruberi, a free-living amoeboflagellate of the Heterolobosea clade, revealed a remarkably complex ancestral eukaryote with a rich repertoire of cytoskeletal-, motility- and signaling-genes. This protist, which diverged from other eukaryotic lineages over a billion years ago, possesses the ability for both amoeboid and flagellar motility. In a phylogenomic comparison of two free living eukaryotes with large proteomic datasets of three metastatic tumour entities (malignant melanoma, breast- and prostate-carcinoma, we find common proteins with potential importance for cell motility and cancer cell metastasis. To identify the underlying signaling modules, we constructed for each tumour type a protein-protein interaction network including these common proteins. The connectivity within this interactome revealed specific interactions and pathways which constitute prospective points of intervention for novel anti-metastatic tumour therapies.

  1. S100A4 is frequently overexpressed in lung cancer cells and promotes cell growth and cell motility

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Na; Sato, Daisuke; Saiki, Yuriko; Sunamura, Makoto; Fukushige, Shinichi; Horii, Akira, E-mail: horii@med.tohoku.ac.jp

    2014-05-09

    Highlights: • We observed frequent overexpression of S100A4 in lung cancer cell lines. • Knockdown of S100A4 suppressed proliferation in lung cancer cells. • Forced expression of S100A4 accelerated cell motility in lung cancer cells. • PRDM2 was found to be one of the downstream suppressed genes of S100A4. - Abstract: S100A4, a small calcium-binding protein belonging to the S100 protein family, is commonly overexpressed in a variety of tumor types and is widely accepted to associate with metastasis by regulating the motility and invasiveness of cancer cells. However, its biological role in lung carcinogenesis is largely unknown. In this study, we found that S100A4 was frequently overexpressed in lung cancer cells, irrespective of histological subtype. Then we performed knockdown and forced expression of S100A4 in lung cancer cell lines and found that specific knockdown of S100A4 effectively suppressed cell proliferation only in lung cancer cells with S100A4-overexpression; forced expression of S100A4 accelerated cell motility only in S100A4 low-expressing lung cancer cells. PRDM2 and VASH1, identified as novel upregulated genes by microarray after specific knockdown of S100A4 in pancreatic cancer, were also analyzed, and we found that PRDM2 was significantly upregulated after S100A4-knockdown in one of two analyzed S100A4-overexpressing lung cancer cells. Our present results suggest that S100A4 plays an important role in lung carcinogenesis by means of cell proliferation and motility by a pathway similar to that in pancreatic cancer.

  2. Intermediate filament Nestin and the cell motility in cancer - a review.

    Science.gov (United States)

    Shi, A-M; Tao, Z-Q; Wang, X; Wang, Y-Q

    2016-06-01

    The intermediate filaments (Ifs) constitute the cytoskeleton which is a key feature of both prokaryotic and eukaryotic cells. The IFs are expressed throughout life and are involved in the regulation of cell differentiation, homeostasis, ageing and pathogenesis. The IFs not only provide structural integrity to the cell, but they are involved also in a range of cellular functions from organelle trafficking and cell migration to signaling transduction. The IFs are highly dynamic proteins, able to respond and adapt their network rapidly in response to intra- and extra-cellular cues. In cancer, these IFs play a crucial role with regard to cell invasion vial cell motility. The present review article will enlighten information about important IF nestin with regard to its role in cancer cell motility and invasion. PMID:27383310

  3. Effects of Roundabout 5 on adhesion, invasion and potential motility of human tongue carcinoma Tb cells

    Institute of Scientific and Technical Information of China (English)

    XIAO Rui; ZHAO yuan; WANG Li-jing; LI Wei-ping

    2011-01-01

    Background Roundabout 5 (R5) is a monoclonal antibody which can neutralize the binding of Roundabout 1 (Robo1)to Slit2. Oral squamous cell carcinoma angiogenesis was significantly inhibited when R5 blocked slit-robo signaling pathway. However, the effect of R5 on the invasion of tongue cancer cells has not been investigated clearly. Methods In this study, we treated human brain metastasis of tongue cancer cell lines (Tb cells) with R5 at different concentrations, and the control Tb cells were treated with 10 mg/ml immunoglobin G 2b (lgG2b). The effect of R5 on the proliferation, adhension, invasion and motility of Tb cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, cell attachment assay on fibronectin (FN), wound assay and chemotaxis assay,respectively. And gelatin-incorporated sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was used to investigate the activity of matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9). Results R5 had no effect on the proliferation of Tb cells. However, R5 could significantly inhibit the motility, attachment and chemotaxis of Tb cells to FN, and it could also significantly inhibit the activity of MMP2 and MMP9 in Tb cells. Conclusion R5 can inhibit the adhesion, invasion and motility of human tongue carcinoma Tb cells.

  4. Cell motility is inhibited by the antiepileptic compound, valproic acid and its teratogenic analogues

    DEFF Research Database (Denmark)

    Walmod, P S; Foley, A; Berezin, A;

    1998-01-01

    Valproic acid (VPA) is an established human teratogen that causes neural tube defects in 1-2% of human foetuses exposed to the drug during early pregnancy. In this study, individual cell motility was evaluated using short- and long-term time-lapse video-recording and computer assisted image analy...

  5. Understanding the Roles of Nudel/Lis1/Dynein Pathway in Cell Motility

    Institute of Scientific and Technical Information of China (English)

    Xie Lele; Zhu Xueliang

    2007-01-01

    @@ Under the support of multiple grants by NSFC, including General Program, Key Program, National Science Fund for Distinguished Young Scholars, and Fund for Creative Research Groups, the research group explored how the Nudel/Lis1/dynein pathway functions in cell motility.

  6. The natural antimicrobial carvacrol inhibits Campylobacter jejuni motility and infection of epithelial cells.

    Directory of Open Access Journals (Sweden)

    Lieke B van Alphen

    Full Text Available BACKGROUND: Natural compounds with anti-microbial properties are attractive reagents to reduce the use of conventional antibiotics. Carvacrol, the main constituent of oregano oil, inhibits the growth of a variety of bacterial foodborne pathogens. As concentrations of carvacrol may vary in vivo or when used in animal feed, we here investigated the effect of subinhibitory concentrations of the compound on major virulence traits of the principal bacterial foodborne pathogen Campylobacter jejuni. METHODS/PRINCIPAL FINDINGS: Motility assays revealed that subinhibitory concentrations of carvacrol inhibited the motility of C. jejuni without affecting bacterial growth. Immunoblotting and electron microscopy showed that carvacrol-treated C. jejuni still expressed flagella. The loss of motility was not caused by reduced intracellular ATP levels. In vitro infection assays demonstrated that subinhibitory concentrations of carvacrol also abolished C. jejuni invasion of human epithelial cells. Bacterial uptake of invasive Escherichia coli was not blocked by carvacrol. Exposure of C. jejuni to carvacrol prior to infection also inhibited cellular infection, indicating that the inhibition of invasion was likely caused by an effect on the bacteria rather than inhibition of epithelial cell function. CONCLUSIONS/SIGNIFICANCE: Bacterial motility and invasion of eukaryotic cells are considered key steps in C. jejuni infection. Our results indicate that subinhibitory concentrations of carvacrol effectively block these virulence traits by interfering with flagella function without disturbing intracellular ATP levels. These results broaden the spectrum of anti-microbial activity of carvacrol and support the potential of the compound for use in novel infection prevention strategies.

  7. N-(2-methyl-indol-1H-5-yl)-1-naphthalenesulfonamide: A novel reversible antimitotic agent inhibiting cancer cell motility.

    Science.gov (United States)

    Aceves-Luquero, Clara; Galiana-Roselló, Cristina; Ramis, Guillem; Villalonga-Planells, Ruth; García-España, Enrique; Fernández de Mattos, Silvia; Peláez, Rafael; Llinares, José M; González-Rosende, M Eugenia; Villalonga, Priam

    2016-09-01

    A series of compounds containing the sulfonamide scaffold were synthesized and screened for their in vitro anticancer activity against a representative panel of human cancer cell lines, leading to the identification of N-(2-methyl-1H-indol-5-yl)-1-naphthalenesulfonamide (8e) as a compound showing a remarkable activity across the panel, with IC50 values in the nanomolar-to-low micromolar range. Cell cycle distribution analysis revealed that 8e promoted a severe G2/M arrest, which was followed by cellular senescence as indicated by the detection of senescence-associated β-galactosidase (SA-β-gal) in 8e-treated cells. Prolonged 8e treatment also led to the onset of apoptosis, in correlation with the detection of increased Caspase 3/7 activities. Despite increasing γ-H2A.X levels, a well-established readout for DNA double-strand breaks, in vitro DNA binding studies with 8e did not support interaction with DNA. In agreement with this, 8e failed to activate the cellular DNA damage checkpoint. Importantly, tubulin staining showed that 8e promoted a severe disorganization of microtubules and mitotic spindle formation was not detected in 8e-treated cells. Accordingly, 8e inhibited tubulin polymerization in vitro in a dose-dependent manner and was also able to robustly inhibit cancer cell motility. Docking analysis revealed a compatible interaction with the colchicine-binding site of tubulin. Remarkably, these cellular effects were reversible since disruption of treatment resulted in the reorganization of microtubules, cell cycle re-entry and loss of senescent markers. Collectively, our data suggest that this compound may be a promising new anticancer agent capable of both reducing cancer cell growth and motility. PMID:27349984

  8. Regulation of Actin-Dependent Cytoplasmic Motility by Type II Phytochrome Occurs within Seconds in Vallisneria gigantea Epidermal Cells

    Science.gov (United States)

    Takagi, Shingo; Kong, Sam-Geun; Mineyuki, Yoshinobu; Furuya, Masaki

    2003-01-01

    The effects of light on actin-dependent cytoplasmic motility in epidermal cells of green leaves of the aquatic angiosperm Vallisneria gigantea were investigated quantitatively using a custom-made dynamic image analyzer. Cytoplasmic motility was measured by monitoring changes in the brightness of individual pixels on digitized images taken sequentially under infrared light. Acceleration and deceleration of cytoplasmic motility were regulated photoreversibly by type II phytochrome(s). This phytochrome-dependent induction of cytoplasmic motility did not occur uniformly in cytoplasm but took place as scattered patches in which no particular organelles, including nucleus, existed. The induction became detectable at 2.5 s after the start of irradiation with pulsed red light. In cells exposed to microbeam irradiation, cytoplasmic motility was induced only in sites in the cytoplasm that were irradiated directly, whereas nonirradiated neighboring areas were unaffected. The effect was short-lived, disappearing within a few minutes, and no signal was transmitted from an irradiated cell to its neighbors. Anti-phytochrome antibody–responsive protein(s) was detectable in the leaf extract by immunoblot and zinc blot analyses and in cryosections of the epidermis by immunocytochemistry. Although the phytochrome-dependent cytoplasmic motility was blocked by exogenously applied latrunculin B or cytochalasins, treatment of the dark-adapted cells with Ca2+-chelating reagents induced the cytoplasmic motility. We have proposed a model for the phytochrome regulation of cytoplasmic motility as one of the earliest responses to a light stimulus. PMID:12566576

  9. Regulation of actin-dependent cytoplasmic motility by type II phytochrome occurs within seconds in Vallisneria gigantea epidermal cells.

    Science.gov (United States)

    Takagi, Shingo; Kong, Sam-Geun; Mineyuki, Yoshinobu; Furuya, Masaki

    2003-02-01

    The effects of light on actin-dependent cytoplasmic motility in epidermal cells of green leaves of the aquatic angiosperm Vallisneria gigantea were investigated quantitatively using a custom-made dynamic image analyzer. Cytoplasmic motility was measured by monitoring changes in the brightness of individual pixels on digitized images taken sequentially under infrared light. Acceleration and deceleration of cytoplasmic motility were regulated photoreversibly by type II phytochrome(s). This phytochrome-dependent induction of cytoplasmic motility did not occur uniformly in cytoplasm but took place as scattered patches in which no particular organelles, including nucleus, existed. The induction became detectable at 2.5 s after the start of irradiation with pulsed red light. In cells exposed to microbeam irradiation, cytoplasmic motility was induced only in sites in the cytoplasm that were irradiated directly, whereas nonirradiated neighboring areas were unaffected. The effect was short-lived, disappearing within a few minutes, and no signal was transmitted from an irradiated cell to its neighbors. Anti-phytochrome antibody-responsive protein(s) was detectable in the leaf extract by immunoblot and zinc blot analyses and in cryosections of the epidermis by immunocytochemistry. Although the phytochrome-dependent cytoplasmic motility was blocked by exogenously applied latrunculin B or cytochalasins, treatment of the dark-adapted cells with Ca(2+)-chelating reagents induced the cytoplasmic motility. We have proposed a model for the phytochrome regulation of cytoplasmic motility as one of the earliest responses to a light stimulus. PMID:12566576

  10. Automated characterization of cell shape changes during amoeboid motility by skeletonization

    Directory of Open Access Journals (Sweden)

    Robinson Douglas N

    2010-03-01

    Full Text Available Abstract Background The ability of a cell to change shape is crucial for the proper function of many cellular processes, including cell migration. One type of cell migration, referred to as amoeboid motility, involves alternating cycles of morphological expansion and retraction. Traditionally, this process has been characterized by a number of parameters providing global information about shape changes, which are insufficient to distinguish phenotypes based on local pseudopodial activities that typify amoeboid motility. Results We developed a method that automatically detects and characterizes pseudopodial behavior of cells. The method uses skeletonization, a technique from morphological image processing to reduce a shape into a series of connected lines. It involves a series of automatic algorithms including image segmentation, boundary smoothing, skeletonization and branch pruning, and takes into account the cell shape changes between successive frames to detect protrusion and retraction activities. In addition, the activities are clustered into different groups, each representing the protruding and retracting history of an individual pseudopod. Conclusions We illustrate the algorithms on movies of chemotaxing Dictyostelium cells and show that our method makes it possible to capture the spatial and temporal dynamics as well as the stochastic features of the pseudopodial behavior. Thus, the method provides a powerful tool for investigating amoeboid motility.

  11. Mutant p53 in cell adhesion and motility.

    Science.gov (United States)

    Yeudall, W Andrew; Wrighton, Katharine H; Deb, Sumitra

    2013-01-01

    Pro-oncogenic properties of mutant p53 were investigated with the aid of migration assays, adhesion assays, and soft agar growth assays using cells stably expressing gain-of-function p53 mutants. To determine cell migration, "wound-healing" (scratch) assays and haptotactic (chamber) assays were used. H1299 cells expressing mutant p53 were found to migrate more rapidly than cells transfected with empty vector alone. Results from both types of migration assay were broadly similar. Migratory ability differed for different p53 mutants, suggesting allele-specific effects. Cells expressing p53 mutants also showed enhanced adhesion to extracellular matrix compare to controls. Furthermore, stable transfection of mutant p53-H179L into NIH3T3 fibroblasts was sufficient to allow anchorage-independent growth in soft agar. PMID:23150443

  12. Genistein inhibits cell invasion and motility by inducing cell differentiation in murine osteosarcoma cell line LM8

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    Nakamura Atsushi

    2012-09-01

    Full Text Available Abstract Background One of the problems associated with osteosarcoma is the frequent formation of micrometastases in the lung prior to diagnosis because the development of metastatic lesions often causes a fatal outcome. Therefore, the prevention of pulmonary metastases during the early stage of tumor development is critical for the improvement of the prognosis of osteosarcoma patients. In Japan, soy is consumed in a wide variety of forms, such as miso soup and soy sauce. The purpose of this study is to investigate the effect of genistein, an isoflavone found in soy, on the invasive and motile potential of osteosarcoma cells. Methods LM8 cells were treated for 3 days with various concentrations of genistein. The effect of genistein on cell proliferation was determined by DNA measurement in the cultures and 5-bromo-2’-deoxyuridine (BrdU incorporation study. The assays of cell invasion and motility were performed using the cell culture inserts with either matrigel-coated membranes or uncoated membranes in the invasion chambers. The expression and secretion of MMP-2 were determined by immunohistochemistry and gelatin zymography. The subcellular localization and cellular level of β-catenin were determined by immunofluorescence and Western blot. For examining cell morphology, the ethanol-fixed cells were stained with hematoxylin-eosin (H&E. The expression of osteocalcin mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR. Results Genistein dose-dependently inhibits cell proliferation. Genistein-treated cells were less invasive and less motile than untreated cells. The expression and secretion of MMP-2 were lower in the genistein-treated cultures than in the untreated cultures. β-Catenin in untreated cells was located in the cytoplasm and/or nucleus, while in genistein-treated cells it was translocated near to the plasma membrane. The level of β-catenin was higher in genistein-treated cells than in untreated cells

  13. Optimization of cell motility evaluation in scratch assay

    Directory of Open Access Journals (Sweden)

    Gotsulyak N. Ya.

    2014-05-01

    Full Text Available A scratch test is one of the most popular methods of classical cell migration assay in a monolayer culture. At the same time, the scratch assay has some disadvantages that can be easily corrected. Aim. Optimization the existent scratch assay on the base of detection of scratch wound surface area and the length of the field of observation which is more objective and less time consuming. Methods. Scratch assay. Results. The modification of scratch assay enables to perform measurement more accurately and rapidly. This approach is more simple and eliminates the main disadvantages of the classical method. Conclusions. The procedure of scratch wound width measurement calculated on the base of detection of cell free area and the length of the field of observation is more effective than the classical wound healing assay. It will be useful for the estimation of cell migration dynamics in monolayer culture for a wide range of live cell based experiments.

  14. RNAi screen reveals host cell kinases specifically involved in Listeria monocytogenes spread from cell to cell.

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    Ryan Chong

    Full Text Available Intracellular bacterial pathogens, such as Listeria monocytogenes and Rickettsia conorii display actin-based motility in the cytosol of infected cells and spread from cell to cell through the formation of membrane protrusions at the cell cortex. Whereas the mechanisms supporting cytosolic actin-based motility are fairly well understood, it is unclear whether specific host factors may be required for supporting the formation and resolution of membrane protrusions. To address this gap in knowledge, we have developed high-throughput fluorescence microscopy and computer-assisted image analysis procedures to quantify pathogen spread in human epithelial cells. We used the approach to screen a siRNA library covering the human kinome and identified 7 candidate kinases whose depletion led to severe spreading defects in cells infected with L. monocytogenes. We conducted systematic validation procedures with redundant silencing reagents and confirmed the involvement of the serine/threonine kinases, CSNK1A1 and CSNK2B. We conducted secondary assays showing that, in contrast with the situation observed in CSNK2B-depleted cells, L. monocytogenes formed wild-type cytosolic tails and displayed wild-type actin-based motility in the cytosol of CSNK1A1-depleted cells. Furthermore, we developed a protrusion formation assay and showed that the spreading defect observed in CSNK1A1-depleted cells correlated with the formation of protrusion that did not resolve into double-membrane vacuoles. Moreover, we developed sending and receiving cell-specific RNAi procedures and showed that CSNK1A was required in the sending cells, but was dispensable in the receiving cells, for protrusion resolution. Finally, we showed that the observed defects were specific to Listeria monocytogenes, as Rickettsia conorii displayed wild-type cell-to-cell spread in CSNK1A1- and CSNK2B-depleted cells. We conclude that, in addition to the specific host factors supporting cytosolic actin

  15. T Cell Interstitial Migration: Motility Cues from the Inflamed Tissue for Micro- and Macro-Positioning

    Science.gov (United States)

    Gaylo, Alison; Schrock, Dillon C.; Fernandes, Ninoshka R. J.; Fowell, Deborah J.

    2016-01-01

    Effector T cells exit the inflamed vasculature into an environment shaped by tissue-specific structural configurations and inflammation-imposed extrinsic modifications. Once within interstitial spaces of non-lymphoid tissues, T cells migrate in an apparent random, non-directional, fashion. Efficient T cell scanning of the tissue environment is essential for successful location of infected target cells or encounter with antigen-presenting cells that activate the T cell’s antimicrobial effector functions. The mechanisms of interstitial T cell motility and the environmental cues that may promote or hinder efficient tissue scanning are poorly understood. The extracellular matrix (ECM) appears to play an important scaffolding role in guidance of T cell migration and likely provides a platform for the display of chemotactic factors that may help to direct the positioning of T cells. Here, we discuss how intravital imaging has provided insight into the motility patterns and cellular machinery that facilitates T cell interstitial migration and the critical environmental factors that may optimize the efficiency of effector T cell scanning of the inflamed tissue. Specifically, we highlight the local micro-positioning cues T cells encounter as they migrate within inflamed tissues, from surrounding ECM and signaling molecules, as well as a requirement for appropriate long-range macro-positioning within distinct tissue compartments or at discrete foci of infection or tissue damage. The central nervous system (CNS) responds to injury and infection by extensively remodeling the ECM and with the de novo generation of a fibroblastic reticular network that likely influences T cell motility. We examine how inflammation-induced changes to the CNS landscape may regulate T cell tissue exploration and modulate function. PMID:27790220

  16. Computer Simulations of Mechano-Chemical Networks Choreographing Actin Dynamics in Cell Motility

    Science.gov (United States)

    Zhuravlev, Pavel I.; Hu, Longhua; Papoian, Garegin A.

    In eukaryotic cells, cell motility is largely driven by self-assembly and growth of filamentous networks comprised of actin. Numerous proteins regulate actin network dynamics either biochemically, or through mechanical interactions. This regulation is rather complex, intricately coordinated both spatially and temporally. Although experiments in vivo and in vitro have provided a trove of structural and biochemical information about actin-based cell motility processes, experimental data is not always easy to interpret unambiguously, sometimes various interpretations being in contradiction with each other. Hence, mathematical modeling approaches are necessary for providing a physical foundation for interpreting and guiding experiments. In particular, computer simulations based on physicochemical interactions provide a systems-level description of protrusion dynamics. In this contribution, we review recent progress in modeling actin-based cell motility using detailed computer simulations. We elaborate on the way actin network dynamics is determined by the interplay between chemical reactions, mechanical feedbacks, and transport bottlenecks. We also discuss the role of inherent randomness of elementary chemical reactions in determining the dynamical behavior of the mechano-chemical network controlling actin polymerization and growth.

  17. Concerted action of two formins in gliding motility and host cell invasion by Toxoplasma gondii.

    Directory of Open Access Journals (Sweden)

    Wassim Daher

    Full Text Available The invasive forms of apicomplexan parasites share a conserved form of gliding motility that powers parasite migration across biological barriers, host cell invasion and egress from infected cells. Previous studies have established that the duration and direction of gliding motility are determined by actin polymerization; however, regulators of actin dynamics in apicomplexans remain poorly characterized. In the absence of a complete ARP2/3 complex, the formin homology 2 domain containing proteins and the accessory protein profilin are presumed to orchestrate actin polymerization during host cell invasion. Here, we have undertaken the biochemical and functional characterization of two Toxoplasma gondii formins and established that they act in concert as actin nucleators during invasion. The importance of TgFRM1 for parasite motility has been assessed by conditional gene disruption. The contribution of each formin individually and jointly was revealed by an approach based upon the expression of dominant mutants with modified FH2 domains impaired in actin binding but still able to dimerize with their respective endogenous formin. These mutated FH2 domains were fused to the ligand-controlled destabilization domain (DD-FKBP to achieve conditional expression. This strategy proved unique in identifying the non-redundant and critical roles of both formins in invasion. These findings provide new insights into how controlled actin polymerization drives the directional movement required for productive penetration of parasites into host cells.

  18. Inorganic sulfur reduces the motility and invasion of MDA-MB-231 human breast cancer cells

    OpenAIRE

    Kim, Jin Joo; Ha, Ae Wha; Kim, Hee Sun; Kim, Woo Kyoung

    2011-01-01

    This study investigated the effects of inorganic sulfur on metastasis in MDA-MB-231 human breast cancer cells. MDA-MB-231 cells were cultured in the absence or presence of various concentrations (12.5, 25, or 50 µmol/L) of inorganic sulfur. Cell motility, invasion, and the activity and mRNA expression of matrix metalloproteases (MMPs) were examined. Numbers of viable MDA-MB-231 cells did not differ by inorganic sulfur treatment from 0 to 50 µmol/L within 48 h. Inorganic sulfur significantly d...

  19. Simulated Hypergravity Alters Vascular Smooth Muscle Cell Proliferation and Motility

    Science.gov (United States)

    Hunt, Shameka; Bettis, Barika; Harris-Hooker, Sandra; Sanford, Gary L.

    1997-01-01

    The cellular effects of gravity are poorly understood due to its constancy and nonavailability of altered gravitational models. Such an understanding is crucial for prolonged space flights. In these studies, we assessed the influence of centrifugation at 6G (HGrav) on vascular smooth muscle (SMC) mobility and proliferation. Cells were: (a) plated at low density and subjected to HGrav for 24-72 hr for proliferation studies, or (b) grown to confluency, subjected to HGrav, mechanically denuded and monitored for cell movement into the denuded area. Controls were maintained under normogravity. SMC showed a 50% inhibition of growth under HGrav and 10% serum; HGrav and low serum resulted in greater growth inhibition. The rate of movement of SMC into the denuded area was 2-3-fold higher under HGrav in low serum compared to controls, but similar in 10% serum. These studies show that HGrav has significant effects on SMC growth and mobility, which are dependent on serum levels.

  20. ACID-EXTRUDING TRANSPORTERS IN MAMMARY AND PANCREATIC ADENOCARCINOMA: REGULATION AND ROLES IN CELL MOTILITY

    OpenAIRE

    Pedersen, S.

    2013-01-01

    A fundamental property of solid tumors is an altered pH-profile compared to normal tissues. This at least in part reflects increased glycolytic metabolism, necessitating increased acid extrusion to maintain survival, and in turn stimulating cancer cell motility [1, 2]. Acid extruding transporters are therefore interesting potential targets in cancer. The overall aim of these studies was to explore the regulation and roles of acid extruding transporters in human mammary and pancreatic adenocar...

  1. Effect of cell physicochemical characteristics and motility on bacterial transport in groundwater

    Science.gov (United States)

    Becker, M.W.; Collins, S.A.; Metge, D.W.; Harvey, R.W.; Shapiro, A.M.

    2004-01-01

    The influence of physicochemical characteristics and motility on bacterial transport in groundwater were examined in flow-through columns. Four strains of bacteria isolated from a crystalline rock groundwater system were investigated, with carboxylate-modified and amidine-modified latex microspheres and bromide as reference tracers. The bacterial isolates included a gram-positive rod (ML1), a gram-negative motile rod (ML2), a nonmotile mutant of ML2 (ML2m), and a gram-positive coccoid (ML3). Experiments were repeated at two flow velocities, in a glass column packed with glass beads, and in another packed with iron-oxyhydroxide coated glass beads. Bacteria breakthrough curves were interpreted using a transport equation that incorporates a sorption model from microscopic observation of bacterial deposition in flow-cell experiments. The model predicts that bacterial desorption rate will decrease exponentially with the amount of time the cell is attached to the solid surface. Desorption kinetics appeared to influence transport at the lower flow rate, but were not discernable at the higher flow rate. Iron-oxyhydroxide coatings had a lower-than-expected effect on bacterial breakthrough and no effect on the microsphere recovery in the column experiments. Cell wall type and shape also had minor effects on breakthrough. Motility tended to increase the adsorption rate, and decrease the desorption rate. The transport model predicts that at field scale, desorption rate kinetics may be important to the prediction of bacteria transport rates. ?? 2003 Elsevier B.V. All rights reserved.

  2. The role of the tissue microenvironment in the regulation of cancer cell motility and invasion

    Directory of Open Access Journals (Sweden)

    Brábek Jan

    2010-09-01

    Full Text Available Abstract During malignant neoplastic progression the cells undergo genetic and epigenetic cancer-specific alterations that finally lead to a loss of tissue homeostasis and restructuring of the microenvironment. The invasion of cancer cells through connective tissue is a crucial prerequisite for metastasis formation. Although cell invasion is foremost a mechanical process, cancer research has focused largely on gene regulation and signaling that underlie uncontrolled cell growth. More recently, the genes and signals involved in the invasion and transendothelial migration of cancer cells, such as the role of adhesion molecules and matrix degrading enzymes, have become the focus of research. In this review we discuss how the structural and biomechanical properties of extracellular matrix and surrounding cells such as endothelial cells influence cancer cell motility and invasion. We conclude that the microenvironment is a critical determinant of the migration strategy and the efficiency of cancer cell invasion.

  3. On an evolution equation in a cell motility model

    Science.gov (United States)

    Mizuhara, Matthew S.; Berlyand, Leonid; Rybalko, Volodymyr; Zhang, Lei

    2016-04-01

    This paper deals with the evolution equation of a curve obtained as the sharp interface limit of a non-linear system of two reaction-diffusion PDEs. This system was introduced as a phase-field model of (crawling) motion of eukaryotic cells on a substrate. The key issue is the evolution of the cell membrane (interface curve) which involves shape change and net motion. This issue can be addressed both qualitatively and quantitatively by studying the evolution equation of the sharp interface limit for this system. However, this equation is non-linear and non-local and existence of solutions presents a significant analytical challenge. We establish existence of solutions for a wide class of initial data in the so-called subcritical regime. Existence is proved in a two step procedure. First, for smooth (H2) initial data we use a regularization technique. Second, we consider non-smooth initial data that are more relevant from the application point of view. Here, uniform estimates on the time when solutions exist rely on a maximum principle type argument. We also explore the long time behavior of the model using both analytical and numerical tools. We prove the nonexistence of traveling wave solutions with nonzero velocity. Numerical experiments show that presence of non-linearity and asymmetry of the initial curve results in a net motion which distinguishes it from classical volume preserving curvature motion. This is done by developing an algorithm for efficient numerical resolution of the non-local term in the evolution equation.

  4. Globular adiponectin activates motility and regenerative traits of muscle satellite cells.

    Directory of Open Access Journals (Sweden)

    Tania Fiaschi

    Full Text Available Regeneration of adult injured skeletal muscle is due to activation of satellite cells, a population of stem cells resident beneath the basal lamina. Thus, information on soluble factors affecting satellite cell activation, as well as migration towards injury and fusion into new myofibers are essential. Here, we show that globular adiponectin (gAd, positively affects several features of muscle satellite cells. gAd activates satellite cells to exit quiescence and increases their recruitment towards myotubes. gAd elicits in satellite cells a specific motility program, involving activation of the small GTPase Rac1, as well as expression of Snail and Twist transcription factors driving a proteolytic motility, useful to reach the site of injury. We show that satellite cells produce autocrine full length adiponectin (fAd, which is converted to gAd by activated macrophages. In turns, gAd concurs to attract to the site of injury both satellite cells and macrophages and induces myogenesis in muscle satellite cells. Thus, these findings add a further role for gAd in skeletal muscle, including the hormone among factors participating in muscle regeneration.

  5. Actomyosin-based motility of endoplasmic reticulum and chloroplasts in Vallisneria mesophyll cells.

    Science.gov (United States)

    Liebe, S; Menzel, D

    1995-01-01

    Intracellular localization and motile behaviour of the endoplasmic reticulum (ER), plastids and mitochondria were studied in living mesophyll cells of Vallisneria using the vital fluorochrome 3,3'-dihexyloxacarbocyanine iodide (DIOC6(3)). In quiescent cells, the ER was composed of a three-dimensional network of tubular and lamellar elements. Chloroplasts were distributed evenly throughout the cell periphery and appeared embedded within the ER network. The ER network was relatively stationary, with the exception of rare motile episodes occurring as movement of tubular ER strands and adjacent areas of the polygonal network in localized areas of the cell. During experimental induction of streaming, most of the lamellar ER elements transformed into tubules and together with the chloroplasts they began to translocate to the anticlinal walls to establish the circular streaming around the circumference of the cell. Microwave-accelerated fixation followed by immunofluorescence revealed an hitherto unknown phase of actin reorganization occurring within the cells and most interestingly at the surface of the chloroplasts during streaming induction. Myosin was localized in an ER-like pattern in quiescent as well as in streaming cells, with bright fluorescent label localized on mitochondria and proplastids. In addition, myosin label appeared on the surface of the chloroplasts, preferentially in streaming mesophyll cells. Motile activities were impeded by the actin-depolymerizing drug cytochalasin D (CD), the thioreagent N-ethylmaleimide (NEM), and thapsigargin, an inhibitor of the ER-Ca(2+)-ATPase. These inhibitors also interfered with the integrity of actin filaments, the intracellular distribution of myosin and calcium-homeostasis, respectively. These effects suggested an obligate association of at least one type of myosin with the membranes of ER and smaller organelles and are consistent with the appearance of another type of myosin on the chloroplast surface upon streaming

  6. Prodigiosin inhibits motility and activates bacterial cell death revealing molecular biomarkers of programmed cell death.

    Science.gov (United States)

    Darshan, N; Manonmani, H K

    2016-12-01

    The antimicrobial activity of prodigiosin from Serratia nematodiphila darsh1, a bacterial pigment was tested against few food borne bacterial pathogens Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The mode of action of prodigiosin was studied. Prodigiosin induced bactericidal activity indicating a stereotypical set of biochemical and morphological feature of Programmed cell death (PCD). PCD involves DNA fragmentation, generation of ROS, and expression of a protein with caspase-like substrate specificity in bacterial cells. Prodigiosin was observed to be internalized into bacterial cells and was localized predominantly in the membrane and the nuclear fraction, thus, facilitating intracellular trafficking and then binding of prodigiosin to the bacterial DNA. Corresponding to an increasing concentration of prodigiosin, the level of certain proteases were observed to increase in bacteria studied, thus initiating the onset of PCD. Prodigiosin at a sub-inhibitory concentration inhibits motility of pathogens. Our observations indicated that prodigiosin could be a promising antibacterial agent and could be used in the prevention of bacterial infections. PMID:27460563

  7. Approaches to systems biology. Four methods to study single-cell gene expression, cell motility, antibody reactivity, and respiratory metabolism

    DEFF Research Database (Denmark)

    Hagedorn, Peter

    To understand how complex systems, such as cells, function, comprehensive Measurements of their constituent parts must be made. This can be achieved by combining methods that are each optimized to measure specific parts of the system. Four such methods,each covering a different area, are presented......: Transcript profiling of one cell type extracted from a complex tissue containing several cell types; observation and recording of cell motility; measurement of antibody reactivities using microarrays; and invivo measurement of free and bound NADH in mitochondria. Detailed statistical analysis of the data...... from such measurements allows models of the system to be developed and tested. For each of the methods, such analysis and modelling approaches have beenapplied and are presented: Differentially regulated genes are identified and classified according to function; cell-specfic motility models...

  8. Tetrathiomolybdate inhibits head and neck cancer metastasis by decreasing tumor cell motility, invasiveness and by promoting tumor cell anoikis

    Directory of Open Access Journals (Sweden)

    Merajver Sofia D

    2010-08-01

    Full Text Available Abstract Background The metastatic spread of solid tumors is directly or indirectly responsible for most cancer-related deaths. Tumor metastasis is very complex and this process requires a tumor cell to acquire enhanced motility, invasiveness and anoikis resistance to successfully establish a tumor at a distal site. Metastatic potential of tumor cells is directly correlated with the expression levels of several angiogenic cytokines. Copper is a mandatory cofactor for the function of many of these angiogenic mediators as well as other proteins that play an important role in tumor cell motility and invasiveness. We have previously shown that tetrathiomolybdate (TM is a potent chelator of copper and it mediates its anti-tumor effects by suppressing tumor angiogenesis. However, very little is known about the effect of TM on tumor cell function and tumor metastasis. In this study, we explored the mechanisms underlying TM-mediated inhibition of tumor metastasis. Results We used two in vivo models to examine the effects of TM on tumor metastasis. Animals treated with TM showed a significant decrease in lung metastasis in both in vivo models as compared to the control group. In addition, tumor cells from the lungs of TM treated animals developed significantly smaller colonies and these colonies had significantly fewer tumor cells. TM treatment significantly decreased tumor cell motility and invasiveness by inhibiting lysyl oxidase (LOX activity, FAK activation and MMP2 levels. Furthermore, TM treatment significantly enhanced tumor cell anoikis by activating p38 MAPK cell death pathway and by downregulating XIAP survival protein expression. Conclusions Taken together, these results suggest that TM is a potent suppressor of head and neck tumor metastasis by modulating key regulators of tumor cell motility, invasiveness and anoikis resistance.

  9. Silibinin inhibits triple negative breast cancer cell motility by suppressing TGF-β2 expression.

    Science.gov (United States)

    Kim, Sangmin; Han, Jeonghun; Jeon, Myeongjin; You, Daeun; Lee, Jeongmin; Kim, Hee Jung; Bae, Sarang; Nam, Seok Jin; Lee, Jeong Eon

    2016-08-01

    Transforming growth factor-beta (TGF-β) is a multifunctional cytokine that regulates many biological events including cell motility and angiogenesis. Here, we investigated the role of elevated TGF-β2 level in triple negative breast cancer (TNBC) cells and the inhibitory effect of silibinin on TGF-β2 action in TNBC cells. Breast cancer patients with high TGF-β2 expression have a poor prognosis. The levels of TGF-β2 expression increased significantly in TNBC cells compared with those in non-TNBC cells. In addition, cell motility-related genes such as fibronectin (FN) and matrix metalloproteinase-2 (MMP-2) expression also increased in TNBC cells. Basal FN, MMP-2, and MMP-9 expression levels decreased in response to LY2109761, a dual TGF-β receptor I/II inhibitor, in TNBC cells. TNBC cell migration also decreased in response to LY2109761. Furthermore, we observed that TGF-β2 augmented the FN, MMP-2, and MMP-9 expression levels in a time- and dose-dependent manner. In contrast, TGF-β2-induced FN, MMP-2, and MMP-9 expression levels decreased significantly in response to LY2109761. Interestingly, we found that silibinin decreased TGF-β2 mRNA expression level but not that of TGF-β1 in TNBC cells. Cell migration as well as basal FN and MMP-2 expression levels decreased in response to silibinin. Furthermore, silibinin significantly decreased TGF-β2-induced FN, MMP-2, and MMP-9 expression levels and suppressed the lung metastasis of TNBC cells. Taken together, these results suggest that silibinin suppresses metastatic potential of TNBC cells by inhibiting TGF-β2 expression in TNBC cells. Thus, silibinin may be a promising therapeutic drug to treat TNBC.

  10. Vimentin and post-translational modifications in cell motility during cancer - a review.

    Science.gov (United States)

    Shi, A-M; Tao, Z-Q; Li, R; Wang, Y-Q; Wang, X; Zhao, J

    2016-07-01

    The post-translational modifications (PTMs) are defined as the covalent modification or enzymatic modification of proteins during or after protein biosynthesis. Proteins are synthesized by ribosomes translating mRNA into polypeptide chains, which may then undergo PTM to form the mature protein product. PTMs are important components in cell signaling. Moreover, it is a known fact that PTM regulation offers an immense array and depth of regulatory possibilities. The present review article will focus on their possible role in cancer cell motility with special reference to vimentin, an intermediate filament (IF), as the later is an important process responsible for life-threatening state viz. cancer metastasis. PMID:27383311

  11. Second-harmonic generation scattering directionality predicts tumor cell motility in collagen gels

    Science.gov (United States)

    Burke, Kathleen A.; Dawes, Ryan P.; Cheema, Mehar K.; Van Hove, Amy; Benoit, Danielle S. W.; Perry, Seth W.; Brown, Edward

    2015-05-01

    Second-harmonic generation (SHG) allows for the analysis of tumor collagen structural changes throughout metastatic progression. SHG directionality, measured through the ratio of the forward-propagating to backward-propagating signal (F/B ratio), is affected by collagen fibril diameter, spacing, and disorder of fibril packing within a fiber. As tumors progress, these parameters evolve, producing concurrent changes in F/B. It has been recently shown that the F/B of highly metastatic invasive ductal carcinoma (IDC) breast tumors is significantly different from less metastatic tumors. This suggests a possible relationship between the microstructure of collagen, as measured by the F/B, and the ability of tumor cells to locomote through that collagen. Utilizing in vitro collagen gels of different F/B ratios, we explored the relationship between collagen microstructure and motility of tumor cells in a "clean" environment, free of the myriad cells, and signals found in in vivo. We found a significant relationship between F/B and the total distance traveled by the tumor cell, as well as both the average and maximum velocities of the cells. Consequently, one possible mechanism underlying the observed relationship between tumor F/B and metastatic output in IDC patient samples is a direct influence of collagen structure on tumor cell motility.

  12. BMP-2 Overexpression Augments Vascular Smooth Muscle Cell Motility by Upregulating Myosin Va via Erk Signaling

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2014-01-01

    Full Text Available Background. The disruption of physiologic vascular smooth muscle cell (VSMC migration initiates atherosclerosis development. The biochemical mechanisms leading to dysfunctional VSMC motility remain unknown. Recently, cytokine BMP-2 has been implicated in various vascular physiologic and pathologic processes. However, whether BMP-2 has any effect upon VSMC motility, or by what manner, has never been investigated. Methods. VSMCs were adenovirally transfected to genetically overexpress BMP-2. VSMC motility was detected by modified Boyden chamber assay, confocal time-lapse video assay, and a colony wounding assay. Gene chip array and RT-PCR were employed to identify genes potentially regulated by BMP-2. Western blot and real-time PCR detected the expression of myosin Va and the phosphorylation of extracellular signal-regulated kinases 1/2 (Erk1/2. Immunofluorescence analysis revealed myosin Va expression locale. Intracellular Ca2+ oscillations were recorded. Results. VSMC migration was augmented in VSMCs overexpressing BMP-2 in a dose-dependent manner. siRNA-mediated knockdown of myosin Va inhibited VSMC motility. Both myosin Va mRNA and protein expression significantly increased after BMP-2 administration and were inhibited by Erk1/2 inhibitor U0126. BMP-2 induced Ca2+ oscillations, generated largely by a “cytosolic oscillator”. Conclusion. BMP-2 significantly increased VSMCs migration and myosin Va expression, via the Erk signaling pathway and intracellular Ca2+ oscillations. We provide additional insight into the pathophysiology of atherosclerosis, and inhibition of BMP-2-induced myosin Va expression may represent a potential therapeutic strategy.

  13. A20 inhibits the motility of HCC cells induced by TNF-α

    Science.gov (United States)

    Xiao, Ying; Li, Na; Guo, Chun; Zhang, Lining; Shi, Yongyu

    2016-01-01

    Metastasis of hepatocellular carcinoma (HCC) can be facilitated by TNF-α, a prototypical inflammatory cytokine in the HCC microenvironment. A20 is a negative regulator of NF-κB signaling pathway. In the present study we ask whether A20 plays a role in HCC metastasis. We found that A20 expression was downregulated in the invasive cells of microvascular invasions (MVI) compared with the noninvasive cells in 89 tissue samples from patients with HCC by immunochemistry methods. Overexpression of A20 in HCC cell lines inhibited their motility induced by TNF-α. Furthermore, the overexpression of A20 inhibited epithelial-mesenchymal transition (EMT), FAK activation and RAC1 activity. By contrast, knockdown of A20 in one HCC cell line results in the converse. In addition, the overexpression of A20 restrained the formation of MVI in HCC xenograft in nude mice treated with TNF-α. All the results suggested that A20 functioned as a negative regulator in motility of HCC cells induced by TNF-α. PMID:26909601

  14. A20 inhibits the motility of HCC cells induced by TNF-α.

    Science.gov (United States)

    Wang, Xianteng; Ma, Chao; Zong, Zhaoyun; Xiao, Ying; Li, Na; Guo, Chun; Zhang, Lining; Shi, Yongyu

    2016-03-22

    Metastasis of hepatocellular carcinoma (HCC) can be facilitated by TNF-α, a prototypical inflammatory cytokine in the HCC microenvironment. A20 is a negative regulator of NF-κB signaling pathway. In the present study we ask whether A20 plays a role in HCC metastasis. We found that A20 expression was downregulated in the invasive cells of microvascular invasions (MVI) compared with the noninvasive cells in 89 tissue samples from patients with HCC by immunochemistry methods. Overexpression of A20 in HCC cell lines inhibited their motility induced by TNF-α. Furthermore, the overexpression of A20 inhibited epithelial-mesenchymal transition (EMT), FAK activation and RAC1 activity. By contrast, knockdown of A20 in one HCC cell line results in the converse. In addition, the overexpression of A20 restrained the formation of MVI in HCC xenograft in nude mice treated with TNF-α. All the results suggested that A20 functioned as a negative regulator in motility of HCC cells induced by TNF-α. PMID:26909601

  15. A novel laser vaccine adjuvant increases the motility of antigen presenting cells.

    Directory of Open Access Journals (Sweden)

    Xinyuan Chen

    Full Text Available BACKGROUND: Development of a potent vaccine adjuvant without introduction of any side effects remains an unmet challenge in the field of the vaccine research. METHODOLOGY/PRINCIPAL FINDINGS: We found that laser at a specific setting increased the motility of antigen presenting cells (APCs and immune responses, with few local or systemic side effects. This laser vaccine adjuvant (LVA effect was induced by brief illumination of a small area of the skin or muscle with a nondestructive, 532 nm green laser prior to intradermal (i.d. or intramuscular (i.m. administration of vaccines at the site of laser illumination. The pre-illumination accelerated the motility of APCs as shown by intravital confocal microscopy, leading to sufficient antigen (Ag-uptake at the site of vaccine injection and transportation of the Ag-captured APCs to the draining lymph nodes. As a result, the number of Ag(+ dendritic cells (DCs in draining lymph nodes was significantly higher in both the 1° and 2° draining lymph nodes in the presence than in the absence of LVA. Laser-mediated increases in the motility and lymphatic transportation of APCs augmented significantly humoral immune responses directed against a model vaccine ovalbumin (OVA or influenza vaccine i.d. injected in both primary and booster vaccinations as compared to the vaccine itself. Strikingly, when the laser was delivered by a hair-like diffusing optical fiber into muscle, laser illumination greatly boosted not only humoral but also cell-mediated immune responses provoked by i.m. immunization with OVA relative to OVA alone. CONCLUSION/SIGNIFICANCE: The results demonstrate the ability of this safe LVA to augment both humoral and cell-mediated immune responses. In comparison with all current vaccine adjuvants that are either chemical compounds or biological agents, LVA is novel in both its form and mechanism; it is risk-free and has distinct advantages over traditional vaccine adjuvants.

  16. CXCR4/CXCL12 signaling impacts enamel progenitor cell proliferation and motility in the dental stem cell niche.

    Science.gov (United States)

    Yokohama-Tamaki, Tamaki; Otsu, Keishi; Harada, Hidemitsu; Shibata, Shunichi; Obara, Nobuko; Irie, Kazuharu; Taniguchi, Akiyoshi; Nagasawa, Takashi; Aoki, Kazunari; Caliari, Steven R; Weisgerber, Daniel W; Harley, Brendan A C

    2015-12-01

    Dental stem cells are located at the proximal ends of rodent incisors. These stem cells reside in the dental epithelial stem cell niche, termed the apical bud. We focused on identifying critical features of a chemotactic signal in the niche. Here, we report that CXCR4/CXCL12 signaling impacts enamel progenitor cell proliferation and motility in dental stem cell niche cells. We report cells in the apical bud express CXCR4 mRNA at high levels while expression is restricted in the basal epithelium (BE) and transit-amplifying (TA) cell regions. Furthermore, the CXCL12 ligand is present in mesenchymal cells adjacent to the apical bud. We then performed gain- and loss-of-function analyses to better elucidate the role of CXCR4 and CXCL12. CXCR4-deficient mice contain epithelial cell aggregates, while cell proliferation in mutant incisors was also significantly reduced. We demonstrate in vitro that dental epithelial cells migrate toward sources of CXCL12, whereas knocking down CXCR4 impaired motility and resulted in formation of dense cell colonies. These results suggest that CXCR4 expression may be critical for activation of enamel progenitor cell division and that CXCR4/CXCL12 signaling may control movement of epithelial progenitors from the dental stem cell niche.

  17. Insulin-like Growth Factor I Controls Adhesion Strength Mediated by α5β1 Integrins in Motile Carcinoma Cells

    OpenAIRE

    Lynch, Laura; Vodyanik, Pavel I.; Boettiger, David; Guvakova, Marina A

    2005-01-01

    One of the intriguing questions regarding cell motility concerns the mechanism that makes stationary cells move. Here, we provide the first physical evidence that the onset of breast cancer cell motility in response to insulin-like growth factor I (IGF-I) correlates with lowering of adhesion strength from 2.52 ± 0.20 to 1.52 ± 0.13 μdynes/μm2 in cells attached to fibronectin via α5β1 integrin. The adhesion strength depends on the dose of IGF-I and time of IGF-I treatment. Weakening of cell-ma...

  18. Differential effects on cell motility, embryonic stem cell self-renewal and senescence by diverse Src kinase family inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Tamm, Christoffer, E-mail: christoffer.tamm@imbim.uu.se; Galito, Sara Pijuan, E-mail: sara.pijuan@imbim.uu.se; Anneren, Cecilia, E-mail: cecilia.anneren@imbim.uu.se

    2012-02-15

    The Src family of non-receptor tyrosine kinases (SFKs) has been shown to play an intricate role in embryonic stem (ES) cell maintenance. In the present study we have focused on the underlying molecular mechanisms responsible for the vastly different effects induced by various commonly used SFK inhibitors. We show that several diverse cell types, including fibroblasts completely lacking SFKs, cannot undergo mitosis in response to SU6656 and that this is caused by an unselective inhibition of Aurora kinases. In contrast, PP2 and PD173952 block motility immediately upon exposure and forces cells to grow in dense colonies. The subsequent halt in proliferation of fibroblast and epithelial cells in the center of the colonies approximately 24 h post-treatment appears to be caused by cell-to-cell contact inhibition rather than a direct effect of SFK kinase inhibition. Interestingly, in addition to generating more homogenous and dense ES cell cultures, without any diverse effect on proliferation, PP2 and PD173652 also promote ES cell self-renewal by reducing the small amount of spontaneous differentiation typically observed under standard ES cell culture conditions. These effects could not be mirrored by the use of Gleevec, a potent inhibitor of c-Abl and PDGFR kinases that are also inhibited by PP2. -- Highlights: Black-Right-Pointing-Pointer SFK inhibitor SU6656 induces senescence in mouse ES cells. Black-Right-Pointing-Pointer SU6656 inhibits mitosis in a SFK-independent manner via cross-selectivity for Aurora kinases. Black-Right-Pointing-Pointer SFK inhibitor PP2 impairs cell motility in various cell lines, including mouse ES cells. Black-Right-Pointing-Pointer Ensuing impeded motility, PP2 inhibits proliferation of various cells lines except for mouse ES cells. Black-Right-Pointing-Pointer SFK inhibitors PP2 and PD173952 impede spontaneous differentiation in standard mouse ES culture maintenance.

  19. Differential effects on cell motility, embryonic stem cell self-renewal and senescence by diverse Src kinase family inhibitors

    International Nuclear Information System (INIS)

    The Src family of non-receptor tyrosine kinases (SFKs) has been shown to play an intricate role in embryonic stem (ES) cell maintenance. In the present study we have focused on the underlying molecular mechanisms responsible for the vastly different effects induced by various commonly used SFK inhibitors. We show that several diverse cell types, including fibroblasts completely lacking SFKs, cannot undergo mitosis in response to SU6656 and that this is caused by an unselective inhibition of Aurora kinases. In contrast, PP2 and PD173952 block motility immediately upon exposure and forces cells to grow in dense colonies. The subsequent halt in proliferation of fibroblast and epithelial cells in the center of the colonies approximately 24 h post-treatment appears to be caused by cell-to-cell contact inhibition rather than a direct effect of SFK kinase inhibition. Interestingly, in addition to generating more homogenous and dense ES cell cultures, without any diverse effect on proliferation, PP2 and PD173652 also promote ES cell self-renewal by reducing the small amount of spontaneous differentiation typically observed under standard ES cell culture conditions. These effects could not be mirrored by the use of Gleevec, a potent inhibitor of c-Abl and PDGFR kinases that are also inhibited by PP2. -- Highlights: ► SFK inhibitor SU6656 induces senescence in mouse ES cells. ► SU6656 inhibits mitosis in a SFK-independent manner via cross-selectivity for Aurora kinases. SFK inhibitor PP2 impairs cell motility in various cell lines, including mouse ES cells. ► Ensuing impeded motility, PP2 inhibits proliferation of various cells lines except for mouse ES cells. ► SFK inhibitors PP2 and PD173952 impede spontaneous differentiation in standard mouse ES culture maintenance.

  20. Modulation of Intracellular Calcium Levels by Calcium Lactate Affects Colon Cancer Cell Motility through Calcium-Dependent Calpain

    OpenAIRE

    Pasupathi Sundaramoorthy; Jae Jun Sim; Yeong-Su Jang; Siddhartha Kumar Mishra; Keun-Yeong Jeong; Poonam Mander; Oh Byung Chul; Won-Sik Shim; Seung Hyun Oh; Ky-Youb Nam; Hwan Mook Kim

    2015-01-01

    Cancer cell motility is a key phenomenon regulating invasion and metastasis. Focal adhesion kinase (FAK) plays a major role in cellular adhesion and metastasis of various cancers. The relationship between dietary supplementation of calcium and colon cancer has been extensively investigated. However, the effect of calcium (Ca2+) supplementation on calpain-FAK-motility is not clearly understood. We sought to identify the mechanism of FAK cleavage through Ca2+ bound lactate (CaLa), its downstrea...

  1. Calcium Signalling Triggered by NAADP in T Cells Determines Cell Shape and Motility During Immune Synapse Formation

    Science.gov (United States)

    Nebel, Merle; Zhang, Bo; Odoardi, Francesca; Flügel, Alexander; Potter, Barry V. L.; Guse, Andreas H.

    2016-01-01

    Nicotinic acid adenine dinucleotide phosphate (NAADP) has been implicated as an initial Ca2+ trigger in T cell Ca2+ signalling, but its role in formation of the immune synapse in CD4+ effector T cells has not been analysed. CD4+ T cells are activated by the interaction with peptide-MHCII complexes on the surface of antigen-presenting cells. Establishing a two-cell system including primary rat CD4+ T cells specific for myelin basic protein and rat astrocytes enabled us to mirror this activation process in vitro and to analyse Ca2+ signalling, cell shape changes and motility in T cells during formation and maintenance of the immune synapse. After immune synapse formation, T cells showed strong, antigen-dependent increases in free cytosolic calcium concentration ([Ca2+]i). Analysis of cell shape and motility revealed rounding and immobilization of T cells depending on the amplitude of the Ca2+ signal. NAADP-antagonist BZ194 effectively blocked Ca2+ signals in T cells evoked by the interaction with antigen-presenting astrocytes. BZ194 reduced the percentage of T cells showing high Ca2+ signals thereby supporting the proposed trigger function of NAADP for global Ca2+ signalling. Taken together, the NAADP signalling pathway is further confirmed as a promising target for specific pharmacological intervention to modulate T cell activation. PMID:27747143

  2. Effects of adhesion dynamics and substrate compliance on the shape and motility of crawling cells.

    Directory of Open Access Journals (Sweden)

    Falko Ziebert

    Full Text Available Computational modeling of eukaryotic cells moving on substrates is an extraordinarily complex task: many physical processes, such as actin polymerization, action of motors, formation of adhesive contacts concomitant with both substrate deformation and recruitment of actin etc., as well as regulatory pathways are intertwined. Moreover, highly nontrivial cell responses emerge when the substrate becomes deformable and/or heterogeneous. Here we extended a computational model for motile cell fragments, based on an earlier developed phase field approach, to account for explicit dynamics of adhesion site formation, as well as for substrate compliance via an effective elastic spring. Our model displays steady motion vs. stick-slip transitions with concomitant shape oscillations as a function of the actin protrusion rate, the substrate stiffness, and the rates of adhesion. Implementing a step in the substrate's elastic modulus, as well as periodic patterned surfaces exemplified by alternating stripes of high and low adhesiveness, we were able to reproduce the correct motility modes and shape phenomenology found experimentally. We also predict the following nontrivial behavior: the direction of motion of cells can switch from parallel to perpendicular to the stripes as a function of both the adhesion strength and the width ratio of adhesive to non-adhesive stripes.

  3. MYBPH inhibits NM IIA assembly via direct interaction with NMHC IIA and reduces cell motility

    Energy Technology Data Exchange (ETDEWEB)

    Hosono, Yasuyuki [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan); Usukura, Jiro [Division of Integrated Project, EcoTopia Science Institute, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Yamaguchi, Tomoya; Yanagisawa, Kiyoshi; Suzuki, Motoshi [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan); Takahashi, Takashi, E-mail: tak@med.nagoya-u.ac.jp [Division of Molecular Carcinogenesis, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya 466-8550 (Japan)

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer MYBPH inhibits NMHC IIA assembly and cell motility. Black-Right-Pointing-Pointer MYBPH interacts to assembly-competent NM IIA. Black-Right-Pointing-Pointer MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA. -- Abstract: Actomyosin filament assembly is a critical step in tumor cell migration. We previously found that myosin binding protein H (MYBPH) is directly transactivated by the TTF-1 lineage-survival oncogene in lung adenocarcinomas and inhibits phosphorylation of the myosin regulatory light chain (RLC) of non-muscle myosin IIA (NM IIA) via direct interaction with Rho kinase 1 (ROCK1). Here, we report that MYBPH also directly interacts with an additional molecule, non-muscle myosin heavy chain IIA (NMHC IIA), which was found to occur between MYBPH and the rod portion of NMHC IIA. MYBPH inhibited NMHC IIA assembly and reduced cell motility. Conversely, siMYBPH-induced increased motility was partially, yet significantly, suppressed by blebbistatin, a non-muscle myosin II inhibitor, while more profound effects were attained by combined treatment with siROCK1 and blebbistatin. Electron microscopy observations showed well-ordered paracrystals of NMHC IIA reflecting an assembled state, which were significantly less frequently observed in the presence of MYBPH. Furthermore, an in vitro sedimentation assay showed that a greater amount of NMHC IIA was in an unassembled state in the presence of MYBPH. Interestingly, treatment with a ROCK inhibitor that impairs transition of NM IIA from an assembly-incompetent to assembly-competent state reduced the interaction between MYBPH and NMHC IIA, suggesting that MYBPH has higher affinity to assembly-competent NM IIA. These results suggest that MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA, and negatively regulates actomyosin organization at 2 distinct steps, resulting in firm inhibition of NM IIA assembly.

  4. MYBPH inhibits NM IIA assembly via direct interaction with NMHC IIA and reduces cell motility

    International Nuclear Information System (INIS)

    Highlights: ► MYBPH inhibits NMHC IIA assembly and cell motility. ► MYBPH interacts to assembly-competent NM IIA. ► MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA. -- Abstract: Actomyosin filament assembly is a critical step in tumor cell migration. We previously found that myosin binding protein H (MYBPH) is directly transactivated by the TTF-1 lineage-survival oncogene in lung adenocarcinomas and inhibits phosphorylation of the myosin regulatory light chain (RLC) of non-muscle myosin IIA (NM IIA) via direct interaction with Rho kinase 1 (ROCK1). Here, we report that MYBPH also directly interacts with an additional molecule, non-muscle myosin heavy chain IIA (NMHC IIA), which was found to occur between MYBPH and the rod portion of NMHC IIA. MYBPH inhibited NMHC IIA assembly and reduced cell motility. Conversely, siMYBPH-induced increased motility was partially, yet significantly, suppressed by blebbistatin, a non-muscle myosin II inhibitor, while more profound effects were attained by combined treatment with siROCK1 and blebbistatin. Electron microscopy observations showed well-ordered paracrystals of NMHC IIA reflecting an assembled state, which were significantly less frequently observed in the presence of MYBPH. Furthermore, an in vitro sedimentation assay showed that a greater amount of NMHC IIA was in an unassembled state in the presence of MYBPH. Interestingly, treatment with a ROCK inhibitor that impairs transition of NM IIA from an assembly-incompetent to assembly-competent state reduced the interaction between MYBPH and NMHC IIA, suggesting that MYBPH has higher affinity to assembly-competent NM IIA. These results suggest that MYBPH inhibits RLC and NMHC IIA, independent components of NM IIA, and negatively regulates actomyosin organization at 2 distinct steps, resulting in firm inhibition of NM IIA assembly.

  5. ADAM17 Promotes Motility, Invasion, and Sprouting of Lymphatic Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Renata Mężyk-Kopeć

    Full Text Available Tumor-associated lymphatic vessels actively participate in tumor progression and dissemination. ADAM17, a sheddase for numerous growth factors, cytokines, receptors, and cell adhesion molecules, is believed to promote tumor development, facilitating both tumor cell proliferation and migration, as well as tumor angiogenesis. In this work we addressed the issue of whether ADAM17 may also promote tumor lymphangiogenesis. First, we found that ADAM17 is important for the migratory potential of immortalized human dermal lymphatic endothelial cells (LEC. When ADAM17 was stably silenced in LEC, their proliferation was not affected, but: (i single-cell motility, (ii cell migration through a 3D Matrigel/collagen type I matrix, and (iii their ability to form sprouts in a 3D matrix were significantly diminished. The differences in the cell motility between ADAM17-proficient and ADAM17-silenced cells were eliminated by inhibitors of EGFR and HER2, indicating that ADAM17-mediated shedding of growth factors accounts for LEC migratory potential. Interestingly, ADAM17 depletion affected the integrin surface expression/functionality in LEC. ADAM17-silenced cells adhered to plastic, type I collagen, and fibronectin faster than their ADAM17-proficient counterparts. The difference in adhesion to fibronectin was abolished by a cyclic RGD peptide, emphasizing the involvement of integrins in the process. Using a soluble receptor array, we identified BIG-H3 among several candidate proteins involved in the phenotypic and behavioral changes of LEC upon ADAM17 silencing. In additional assays, we confirmed the increased expression of BIG-H3, as well as TGFβ2 in ADAM17-silenced LEC. The antilymphangiogenic effects of ADAM17 silencing in lymphatic endothelial cells suggest further relevance of ADAM17 as a potential target in cancer therapy.

  6. ADAM17 Promotes Motility, Invasion, and Sprouting of Lymphatic Endothelial Cells.

    Science.gov (United States)

    Mężyk-Kopeć, Renata; Wyroba, Barbara; Stalińska, Krystyna; Próchnicki, Tomasz; Wiatrowska, Karolina; Kilarski, Witold W; Swartz, Melody A; Bereta, Joanna

    2015-01-01

    Tumor-associated lymphatic vessels actively participate in tumor progression and dissemination. ADAM17, a sheddase for numerous growth factors, cytokines, receptors, and cell adhesion molecules, is believed to promote tumor development, facilitating both tumor cell proliferation and migration, as well as tumor angiogenesis. In this work we addressed the issue of whether ADAM17 may also promote tumor lymphangiogenesis. First, we found that ADAM17 is important for the migratory potential of immortalized human dermal lymphatic endothelial cells (LEC). When ADAM17 was stably silenced in LEC, their proliferation was not affected, but: (i) single-cell motility, (ii) cell migration through a 3D Matrigel/collagen type I matrix, and (iii) their ability to form sprouts in a 3D matrix were significantly diminished. The differences in the cell motility between ADAM17-proficient and ADAM17-silenced cells were eliminated by inhibitors of EGFR and HER2, indicating that ADAM17-mediated shedding of growth factors accounts for LEC migratory potential. Interestingly, ADAM17 depletion affected the integrin surface expression/functionality in LEC. ADAM17-silenced cells adhered to plastic, type I collagen, and fibronectin faster than their ADAM17-proficient counterparts. The difference in adhesion to fibronectin was abolished by a cyclic RGD peptide, emphasizing the involvement of integrins in the process. Using a soluble receptor array, we identified BIG-H3 among several candidate proteins involved in the phenotypic and behavioral changes of LEC upon ADAM17 silencing. In additional assays, we confirmed the increased expression of BIG-H3, as well as TGFβ2 in ADAM17-silenced LEC. The antilymphangiogenic effects of ADAM17 silencing in lymphatic endothelial cells suggest further relevance of ADAM17 as a potential target in cancer therapy.

  7. Helicobacter pylori strains vary cell shape and flagellum number to maintain robust motility in viscous environments.

    Science.gov (United States)

    Martínez, Laura E; Hardcastle, Joseph M; Wang, Jeffrey; Pincus, Zachary; Tsang, Jennifer; Hoover, Timothy R; Bansil, Rama; Salama, Nina R

    2016-01-01

    The helical shape of the human stomach pathogen Helicobacter pylori has been suggested to provide mechanical advantage for penetrating the viscous stomach mucus layer. Using single-cell tracking and quantitative morphology analysis, we document marked variation in cell body helical parameters and flagellum number among H. pylori strains leading to distinct and broad speed distributions in broth and viscous gastric mucin media. These distributions reflect both temporal variation in swimming speed and morphologic variation within the population. Isogenic mutants with straight-rod morphology showed 7-21% reduction in speed and a lower fraction of motile bacteria. Mutational perturbation of flagellum number revealed a 19% increase in speed with 4 versus 3 median flagellum number. Resistive force theory modeling incorporating variation of both cell shape and flagellum number predicts qualitative speed differences of 10-30% among strains. However, quantitative comparisons suggest resistive force theory underestimates the influence of cell body shape on speed for helical shaped bacteria.

  8. Fibroblasts Cultured on Nanowires Exhibit Low Motility, Impaired Cell Division, and DNA Damage

    DEFF Research Database (Denmark)

    Persson, H.; Købler, Carsten; Mølhave, Kristian;

    2013-01-01

    beam milling and scanning electron microscopy, highly curved but intact nuclear membranes are observed, showing no direct contact between the nanowires and the DNA. The nanowires possibly induce cellular stress and high respiration rates, which trigger the formation of ROS, which in turn results in DNA......Nanowires are commonly used as tools for interfacing living cells, acting as biomolecule-delivery vectors or electrodes. It is generally assumed that the small size of the nanowires ensures a minimal cellular perturbation, yet the effects of nanowires on cell migration and proliferation remain...... largely unknown. Fibroblast behaviour on vertical nanowire arrays is investigated, and it is shown that cell motility and proliferation rate are reduced on nanowires. Fibroblasts cultured on long nanowires exhibit failed cell division, DNA damage, increased ROS content and respiration. Using focused ion...

  9. ROS accumulation and IGF-IR inhibition contribute to fenofibrate/PPARα -mediated inhibition of Glioma cell motility in vitro

    Directory of Open Access Journals (Sweden)

    Del Valle Luis

    2010-06-01

    Full Text Available Abstract Background Glioblastomas are characterized by rapid cell growth, aggressive CNS infiltration, and are resistant to all known anticancer regimens. Recent studies indicate that fibrates and statins possess anticancer potential. Fenofibrate is a potent agonist of peroxisome proliferator activated receptor alpha (PPARα that can switch energy metabolism from glycolysis to fatty acid β-oxidation, and has low systemic toxicity. Fenofibrate also attenuates IGF-I-mediated cellular responses, which could be relevant in the process of glioblastoma cell dispersal. Methods The effects of fenofibrate on Glioma cell motility, IGF-I receptor (IGF-IR signaling, PPARα activity, reactive oxygen species (ROS metabolism, mitochondrial potential, and ATP production were analyzed in human glioma cell lines. Results Fenofibrate treatment attenuated IGF-I signaling responses and repressed cell motility of LN-229 and T98G Glioma cell lines. In the absence of fenofibrate, specific inhibition of the IGF-IR had only modest effects on Glioma cell motility. Further experiments revealed that PPARα-dependent accumulation of ROS is a strong contributing factor in Glioma cell lines responses to fenofibrate. The ROS scavenger, N-acetyl-cysteine (NAC, restored cell motility, improved mitochondrial potential, and increased ATP levels in fenofibrate treated Glioma cell lines. Conclusions Our results indicate that although fenofibrate-mediated inhibition of the IGF-IR may not be sufficient in counteracting Glioma cell dispersal, PPARα-dependent metabolic switch and the resulting ROS accumulation strongly contribute to the inhibition of these devastating brain tumor cells.

  10. Screen Printed Metallization of Silicon Solar Cells

    OpenAIRE

    Govaerts, R.; Van Overstraeten, R.; Mertens, R.; Ph. Lauwers; Frisson, L.

    1980-01-01

    This paper presents a screen printing process for the metallization of silicon solar cells. The physics and construction of a classical solar cell are reviewed. The results obtained with a screen printing process are comparable with other, more expensive technologies. This technology does not introduce an additional contact resistance on silicon. The process optimization and the influence of different parameters are discussed.

  11. Effects of zinc oxide nanoparticles on Kupffer cell phagosomal motility, bacterial clearance, and liver function

    Directory of Open Access Journals (Sweden)

    Watson CY

    2015-06-01

    Full Text Available Christa Y Watson, Ramon M Molina, Andressa Louzada, Kimberly M Murdaugh, Thomas C Donaghey, Joseph D BrainCenter for Nanotechnology and Nanotoxicology, Molecular and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, USABackground: Zinc oxide engineered nanoparticles (ZnO ENPs have potential as nanomedicines due to their inherent properties. Studies have described their pulmonary impact, but less is known about the consequences of ZnO ENP interactions with the liver. This study was designed to describe the effects of ZnO ENPs on the liver and Kupffer cells after intravenous (IV administration.Materials and methods: First, pharmacokinetic studies were conducted to determine the tissue distribution of neutron-activated 65ZnO ENPs post-IV injection in Wistar Han rats. Then, a noninvasive in vivo method to assess Kupffer cell phagosomal motility was employed using ferromagnetic iron particles and magnetometry. We also examined whether prior IV injection of ZnO ENPs altered Kupffer cell bactericidal activity on circulating Pseudomonas aeruginosa. Serum and liver tissues were collected to assess liver-injury biomarkers and histological changes, respectively.Results: We found that the liver was the major site of initial uptake of 65ZnO ENPs. There was a time-dependent decrease in tissue levels of 65Zn in all organs examined, reflecting particle dissolution. In vivo magnetometry showed a time-dependent and transient reduction in Kupffer cell phagosomal motility. Animals challenged with P. aeruginosa 24 hours post-ZnO ENP injection showed an initial (30 minutes delay in vascular bacterial clearance. However, by 4 hours, IV-injected bacteria were cleared from the blood, liver, spleen, lungs, and kidneys. Seven days post-ZnO ENP injection, creatine phosphokinase and aspartate aminotransferase levels in serum were significantly increased. Histological evidence of

  12. Wnt Signaling in Cell Motility and Invasion: Drawing Parallels between Development and Cancer.

    Science.gov (United States)

    Sedgwick, Alanna E; D'Souza-Schorey, Crislyn

    2016-01-01

    The importance of canonical and non-canonical Wnt signal transduction cascades in embryonic development and tissue homeostasis is well recognized. The aberrant activation of these pathways in the adult leads to abnormal cellular behaviors, and tumor progression is frequently a consequence. Here we discuss recent findings and analogies between Wnt signaling in developmental processes and tumor progression, with a particular focus on cell motility and matrix invasion and highlight the roles of the ARF (ADP-Ribosylation Factor) and Rho-family small GTP-binding proteins. Wnt-regulated signal transduction from cell surface receptors, signaling endosomes and/or extracellular vesicles has the potential to profoundly influence cell movement, matrix degradation and paracrine signaling in both development and disease. PMID:27589803

  13. Heme in intestinal epithelial cell turnover, differentiation,detoxification, inflammation, carcinogenesis, absorption and motility

    Institute of Scientific and Technical Information of China (English)

    Phillip S Oates; Adrian R West

    2006-01-01

    The gastrointestinal tract is lined by a simple epithelium that undergoes constant renewal involving cell division,differentiation and cell death. In addition, the epithelial lining separates the hostile processes of digestion and absorption that occur in the intestinal lumen from the aseptic environment of the internal milieu by defensive mechanisms that protect the epithelium from being breached. Central to these defensive processes is the synthesis of heme and its catabolism by heme oxygenase (HO). Dietary heme is also an important source of iron for the body which is taken up intact by the enterocyte.This review describes the recent literature on the diverse properties of heme/HO in the intestine tract.The roles of heme/HO in the regulation of the cell cycle/apoptosis, detoxification of xenobiotics, oxidative stress,inflammation, development of colon cancer, hemeiron absorption and intestinal motility are specifically examined.

  14. Wnt Signaling in Cell Motility and Invasion: Drawing Parallels between Development and Cancer

    Directory of Open Access Journals (Sweden)

    Alanna E. Sedgwick

    2016-08-01

    Full Text Available The importance of canonical and non-canonical Wnt signal transduction cascades in embryonic development and tissue homeostasis is well recognized. The aberrant activation of these pathways in the adult leads to abnormal cellular behaviors, and tumor progression is frequently a consequence. Here we discuss recent findings and analogies between Wnt signaling in developmental processes and tumor progression, with a particular focus on cell motility and matrix invasion and highlight the roles of the ARF (ADP-Ribosylation Factor and Rho-family small GTP-binding proteins. Wnt-regulated signal transduction from cell surface receptors, signaling endosomes and/or extracellular vesicles has the potential to profoundly influence cell movement, matrix degradation and paracrine signaling in both development and disease.

  15. Calmodulin-dependent protein kinases mediate calcium-induced slow motility of mammalian outer hair cells.

    Science.gov (United States)

    Puschner, B; Schacht, J

    1997-08-01

    Cochlear outer hair cells in vitro respond to elevation of intracellular calcium with slow shape changes over seconds to minutes ('slow motility'). This process is blocked by general calmodulin antagonists suggesting the participation of calcium/calmodulin-dependent enzymatic reactions. The present study proposes a mechanism for these reactions. Length changes of outer hair cells isolated from the guinea pig cochlea were induced by exposure to the calcium ionophore ionomycin. ATP levels remained unaffected by this treatment ruling out depletion of ATP (by activation of calcium-dependent ATPases) as a cause of the observed shape changes. Involvement of protein kinases was suggested by the inhibition of shape changes by K252a, a broad-spectrum inhibitor of protein kinase activity. Furthermore, the inhibitors ML-7 and ML-9 blocked the shape changes at concentrations compatible with inhibition of myosin light chain kinase (MLCK). KN-62, an inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMKII), also attenuated the length changes. Inhibitors with selectivity for cyclic nucleotide-dependent protein kinases (H-89, staurosporine) were tested to assess potential additional contributions by such enzymes. The dose dependence of their action supported the notion that the most likely mechanism of slow motility involves phosphorylation reactions catalyzed by MLCK or CaMKII or both. PMID:9282907

  16. Approaches to myosin modelling in a two-phase flow model for cell motility

    Science.gov (United States)

    Kimpton, L. S.; Whiteley, J. P.; Waters, S. L.; Oliver, J. M.

    2016-04-01

    A wide range of biological processes rely on the ability of cells to move through their environment. Mathematical models have been developed to improve our understanding of how cells achieve motion. Here we develop models that explicitly track the cell's distribution of myosin within a two-phase flow framework. Myosin is a small motor protein which is important for contracting the cell's actin cytoskeleton and enabling cell motion. The two phases represent the actin network and the cytosol in the cell. We start from a fairly general description of myosin kinetics, advection and diffusion in the two-phase flow framework, then identify a number of sub-limits of the model that may be relevant in practice, two of which we investigate further via linear stability analyses and numerical simulations. We demonstrate that myosin-driven contraction of the actin network destabilizes a stationary steady state leading to cell motion, but that rapid diffusion of myosin and rapid unbinding of myosin from the actin network are stabilizing. We use numerical simulation to investigate travelling-wave solutions relevant to a steadily gliding cell and we consider a reduction of the model in which the cell adheres strongly to the substrate on which it is crawling. This work demonstrates that a number of existing models for the effect of myosin on cell motility can be understood as different sub-limits of our two-phase flow model.

  17. The effect of membrane-regulated actin polymerization on a two-phase flow model for cell motility

    KAUST Repository

    Kimpton, L. S.

    2014-07-23

    Two-phase flow models have been widely used to model cell motility and we have previously demonstrated that even the simplest, stripped-down, 1D model displays many observed features of cell motility [Kimpton, L.S., Whiteley, J.P., Waters, S.L., King, J.R. & Oliver, J.M. (2013) Multiple travelling-wave solutions in a minimal model for cell motility. Math. Med. Biol. 30, 241 - 272]. In this paper, we address a limitation of the previous model.We show that the two-phase flow framework can exhibit travelling-wave solutions with biologically plausible actin network profiles in two simple models that enforce polymerization or depolymerization of the actin network at the ends of the travelling, 1D strip of cytoplasm. © 2014 The authors 2014. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  18. RNAi Screening of Leukemia Cells Using Electroporation.

    Science.gov (United States)

    Agarwal, Anupriya; Tyner, Jeffrey W

    2016-01-01

    RNAi-mediated screening has been an integral tool for biological discovery for the past 15 years. A variety of approaches have been employed for implementation of this technique, including pooled, depletion/enrichment screening with lentiviral shRNAs, and segregated screening of panels of individual siRNAs. The latter approach of siRNA panel screening requires efficient methods for transfection of siRNAs into the target cells. In the case of suspension leukemia cell lines and primary cells, many of the conventional transfection techniques using liposomal or calcium phosphate-mediated transfection provide very low efficiency. In this case, electroporation is the only transfection technique offering high efficiency transfection of siRNAs into the target leukemia cells. Here, we describe methods for optimization and implementation of siRNA electroporation into leukemia cell lines and primary patient specimens, and we further offer suggested electroporation settings for some commonly used leukemia cell lines. PMID:27581286

  19. Intracellular photoactivation of caged cGMP induces myosin II and actin responses in motile cells.

    Science.gov (United States)

    Pfannes, Eva K B; Anielski, Alexander; Gerhardt, Matthias; Beta, Carsten

    2013-12-01

    Cyclic GMP (cGMP) is a ubiquitous second messenger in eukaryotic cells. It is assumed to regulate the association of myosin II with the cytoskeleton of motile cells. When cells of the social amoeba Dictyostelium discoideum are exposed to chemoattractants or to increased osmotic stress, intracellular cGMP levels rise, preceding the accumulation of myosin II in the cell cortex. To directly investigate the impact of intracellular cGMP on cytoskeletal dynamics in a living cell, we released cGMP inside the cell by laser-induced photo-cleavage of a caged precursor. With this approach, we could directly show in a live cell experiment that an increase in intracellular cGMP indeed induces myosin II to accumulate in the cortex. Unexpectedly, we observed for the first time that also the amount of filamentous actin in the cell cortex increases upon a rise in the cGMP concentration, independently of cAMP receptor activation and signaling. We discuss our results in the light of recent work on the cGMP signaling pathway and suggest possible links between cGMP signaling and the actin system. PMID:24136144

  20. Knockdown of OLA1, a regulator of oxidative stress response, inhibits motility and invasion of breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Jia-wei ZHANG; Valentina RUBIO; Shu ZHENG; Zheng-zheng SHI

    2009-01-01

    To explore the role of a novel Obg-like ATPase 1 (OLA1) in cancer metastasis, small interference RNA (siRNA) was used to knockdown the protein, and the cells were subjected to in vitro cell migration and invasion assays. Knockdown of OLA1 significantly inhibited cell migration and invasion in breast cancer cell line MDA-MB-231. The knockdown caused no changes in cell growth but affected ROS production. In wound-healing assays, decreased ROS in OLA1-knockdown cells were in situ asso-ciated with the cells' decreased motile morphology. Further, treatment of N-acetylcysteine, a general ROS scavenger, blunted the motility and invasiveness of MDA-MB-231 cells, similar to the effect of OLA1-knockdown. These results suggest that knock-down of OLA1 inhibits breast cancer cell migration and invasion through a mechanism that involves the modulation of intracel-lular ROS levels.

  1. The HP0256 gene product is involved in motility and cell envelope architecture of Helicobacter pylori

    LENUS (Irish Health Repository)

    Douillard, Francois P

    2010-04-08

    Abstract Background Helicobacter pylori is the causative agent for gastritis, and peptic and duodenal ulcers. The bacterium displays 5-6 polar sheathed flagella that are essential for colonisation and persistence in the gastric mucosa. The biochemistry and genetics of flagellar biogenesis in H. pylori has not been fully elucidated. Bioinformatics analysis suggested that the gene HP0256, annotated as hypothetical, was a FliJ homologue. In Salmonella, FliJ is a chaperone escort protein for FlgN and FliT, two proteins that themselves display chaperone activity for components of the hook, the rod and the filament. Results Ablation of the HP0256 gene in H. pylori significantly reduced motility. However, flagellin and hook protein synthesis was not affected in the HP0256 mutant. Transmission electron transmission microscopy revealed that the HP0256 mutant cells displayed a normal flagellum configuration, suggesting that HP0256 was not essential for assembly and polar localisation of the flagella in the cell. Interestingly, whole genome microarrays of an HP0256 mutant revealed transcriptional changes in a number of genes associated with the flagellar regulon and the cell envelope, such as outer membrane proteins and adhesins. Consistent with the array data, lack of the HP0256 gene significantly reduced adhesion and the inflammatory response in host cells. Conclusions We conclude that HP0256 is not a functional counterpart of FliJ in H. pylori. However, it is required for full motility and it is involved, possibly indirectly, in expression of outer membrane proteins and adhesins involved in pathogenesis and adhesion.

  2. SMAD4 regulates cell motility through transcription of N-cadherin in human pancreatic ductal epithelium.

    Directory of Open Access Journals (Sweden)

    Ya'an Kang

    Full Text Available Expression of the cellular adhesion protein N-cadherin is a critical event during epithelial-mesenchymal transition (EMT. The SMAD4 protein has been identified as a mediator of transforming growth factor-β (TGF-β superfamily signaling, which regulates EMT, but the mechanisms linking TGF-β signaling to N-cadherin expression remain unclear. When the TGF-β pathway is activated, SMAD proteins, including the common mediator SMAD4, are subsequently translocated into the nucleus, where they influence gene transcription via SMAD binding elements (SBEs. Here we describe a mechanism for control of CDH2, the gene encoding N-cadherin, through the canonical TGFβ-SMAD4 pathway. We first identified four previously undescribed SBEs within the CDH2 promoter. Using telomerase immortalized human pancreatic ductal epithelium, we found that TGF-β stimulation prompted specific SMAD4 binding to all four SBEs. Luciferase reporter and SMAD4-knockdown experiments demonstrated that specific SMAD4 binding to the SBE located at -3790 bp to -3795 bp within the promoter region of CDH2 was necessary for TGF-β-stimulated transcription. Expression of N-cadherin on the surface of epithelial cells facilitates motility and invasion, and we demonstrated that knockdown of SMAD4 causes decreased N-cadherin expression, which results in diminished migration and invasion of human pancreatic ductal epithelial cells. Similar reduction of cell motility was produced after CDH2 knockdown. Together, these findings suggest that SMAD4 is critical for the TGF-β-driven upregulation of N-cadherin and the resultant invasive phenotype of human pancreatic ductal epithelial cells during EMT.

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

    Science.gov (United States)

    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.

  4. Dose dependent side effect of superparamagnetic iron oxide nanoparticle labeling on cell motility in two fetal stem cell populations.

    Directory of Open Access Journals (Sweden)

    Valentina Diana

    Full Text Available Multipotent stem cells (SCs could substitute damaged cells and also rescue degeneration through the secretion of trophic factors able to activate the endogenous SC compartment. Therefore, fetal SCs, characterized by high proliferation rate and devoid of ethical concern, appear promising candidate, particularly for the treatment of neurodegenerative diseases. Super Paramagnetic Iron Oxide nanoparticles (SPIOn, routinely used for pre-clinical cell imaging and already approved for clinical practice, allow tracking of transplanted SCs and characterization of their fate within the host tissue, when combined with Magnetic Resonance Imaging (MRI. In this work we investigated how SPIOn could influence cell migration after internalization in two fetal SC populations: human amniotic fluid and chorial villi SCs were labeled with SPIOn and their motility was evaluated. We found that SPIOn loading significantly reduced SC movements without increasing production of Reactive Oxygen Species (ROS. Moreover, motility impairment was directly proportional to the amount of loaded SPIOn while a chemoattractant-induced recovery was obtained by increasing serum levels. Interestingly, the migration rate of SPIOn labeled cells was also significantly influenced by a degenerative surrounding. In conclusion, this work highlights how SPIOn labeling affects SC motility in vitro in a dose-dependent manner, shedding the light on an important parameter for the creation of clinical protocols. Establishment of an optimal SPIOn dose that enables both a good visualization of grafted cells by MRI and the physiological migration rate is a main step in order to maximize the effects of SC therapy in both animal models of neurodegeneration and clinical studies.

  5. Regulation of T cell motility in vitro and in vivo by LPA and LPA2.

    Directory of Open Access Journals (Sweden)

    Sara A Knowlden

    Full Text Available Lysophosphatidic acid (LPA and the LPA-generating enzyme autotaxin (ATX have been implicated in lymphocyte trafficking and the regulation of lymphocyte entry into lymph nodes. High local concentrations of LPA are thought to be present in lymph node high endothelial venules, suggesting a direct influence of LPA on cell migration. However, little is known about the mechanism of action of LPA, and more work is needed to define the expression and function of the six known G protein-coupled receptors (LPA 1-6 in T cells. We studied the effects of 18∶1 and 16∶0 LPA on naïve CD4+ T cell migration and show that LPA induces CD4+ T cell chemorepulsion in a Transwell system, and also improves the quality of non-directed migration on ICAM-1 and CCL21 coated plates. Using intravital two-photon microscopy, lpa2-/- CD4+ T cells display a striking defect in early migratory behavior at HEVs and in lymph nodes. However, later homeostatic recirculation and LPA-directed migration in vitro were unaffected by loss of lpa2. Taken together, these data highlight a previously unsuspected and non-redundant role for LPA2 in intranodal T cell motility, and suggest that specific functions of LPA may be manipulated by targeting T cell LPA receptors.

  6. Signaling networks and cell motility: a computational approach using a phase field description.

    Science.gov (United States)

    Marth, Wieland; Voigt, Axel

    2014-07-01

    The processes of protrusion and retraction during cell movement are driven by the turnover and reorganization of the actin cytoskeleton. Within a reaction-diffusion model which combines processes along the cell membrane with processes within the cytoplasm a Turing type instability is used to form the necessary polarity to distinguish between cell front and rear and to initiate the formation of different organizational arrays within the cytoplasm leading to protrusion and retraction. A simplified biochemical network model for the activation of GTPase which accounts for the different dimensionality of the cell membrane and the cytoplasm is used for this purpose and combined with a classical Helfrich type model to account for bending and stiffness effects of the cell membrane. In addition streaming within the cytoplasm and the extracellular matrix is taken into account. Combining these phenomena allows to simulate the dynamics of cells and to reproduce the primary phenomenology of cell motility. The coupled model is formulated within a phase field approach and solved using adaptive finite elements. PMID:23835784

  7. Characterization of a synthetic peptide from type IV collagen that promotes melanoma cell adhesion, spreading, and motility

    OpenAIRE

    1990-01-01

    The adhesion and motility of tumor cells on basement membranes is a central consideration in tumor cell invasion and metastasis. Basement membrane type IV collagen directly promotes the adhesion and migration of various tumor cell types in vitro. Our previous studies demonstrated that tumor cells adhered and spread on surfaces coated with intact type IV collagen or either of the two major enzymatically purified domains of this protein. Only one of these major domains, the pepsin-generated maj...

  8. Irradiation effects of ultraviolet rays on Leptospira cells. Loss of motility, survive ability, and damages of cell structures

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Hidezo (Yamaguchi Univ., Ube (Japan). School of Medicine)

    1982-12-01

    The irradiation effects of ultraviolets rays (UV) on leptospira cells were investigated. Four serovar strains of Genus Leptospira ; L. copenhageni, L. canicola, L. biflexa and L. illini were used. A sterilization lamp (Toshiba-GL-15) was lighted at intervals of 90mm on the sample fluid for several minutes. Loss of motility, survival growth and morphological damages were recognized under several conditions. The medium conditions were important, that is, the Korthof's medium was less effective than phosphate buffered saline (PBS). The irradiation time was also important, that is, L. canicola cells in PBS lost their motility and survive ability within 300sec. of irradiation, however, much more time, such as 1.200sec. was necessary in Korthof's medium. This phenomenon may be depended upon defensibility of albumin in the latter. Among the strains, L. biflexa cells showed the highest resistance in loss of motility and survive ability, and other three strains were inferior. The remarkable efects of cellular structures were also seen in the materials with 30 min. of irradiation, in both immediate time or after 24h incubation. The damages observed after 24th of irradiation were much more drastic than those of immediate time. No effect could be seen on the cells suspended in the Korthof's medium irradiated for 24h. Regarding morphological effect, there appeared relaxation of helical body, spherical body and semighost as the immediate changes. Structural damages were recognized as the collapse of cell body, such as scattering of capsule, release of axial flagella, loss or change of cytoplasmic density and break down of wall membrane complex. These phenomena were regarded as the indirect effects of UV-irradiation and autolysis in a post-mortem change.

  9. Slow motility in hair cells of the frog amphibian papilla: Ca2+-dependent shape changes.

    Science.gov (United States)

    Farahbakhsh, Nasser A; Narins, Peter M

    2006-02-01

    We investigated the process of slow motility in non-mammalian auditory hair cells by recording the time course of shape change in hair cells of the frog amphibian papilla. The tall hair cells in the rostral segment of this organ, reported to be the sole recipients of efferent innervation, were found to shorten in response to an increase in the concentration of the intracellular free calcium. These shortenings are composed of two partially-overlapping phases: an initial rapid iso-volumetric contraction, followed by a slower length decrease accompanied with swelling. It is possible to unmask the iso-volumetric contraction by delaying the cell swelling with the help of K+ or Cl- channel inhibitors, quinine or furosemide. Furthermore, it appears that the longitudinal contraction in these cells is Ca2+-calmodulin-dependent: in the presence of W-7, a calmodulin inhibitor, only a slow, swelling phase could be observed. These findings suggest that amphibian rostral AP hair cells resemble their mammalian counterparts in expressing both a Ca2+-calmodulin-dependent contractile structure and an "osmotic" mechanism capable of mediating length change in response to extracellular stimuli. Such a mechanism might be utilized by the efferent neurotransmitters for adaptive modulation of mechano-electrical transduction, sensitivity enhancement, frequency selectivity, and protection against over-stimulation.

  10. The Long Non-Coding RNA ENST00000537266 and ENST00000426615 Influence Papillary Thyroid Cancer Cell Proliferation and Motility

    Directory of Open Access Journals (Sweden)

    Bo Xu

    2016-01-01

    Full Text Available Background/Aims: Papillary thyroid cancer (PTC is the most common histotype of Thyroid cancer (TC. Here, we detected the differentially expressed lncRNAs in tumor tissues and non-tumor tissues of PTC patients by lncRNA microarrays, and explored the function and molecular mechanisms of lncRNAs in the pathogenesis of PTC using a PTC cell line. Methods: CCK-8 assay, colony formation assay and EdU assay were used to detect the cell viability. Flow Cytometry was used to detect the cell cycle and apoptosis. Transwell and scratch assay were used to detect the cell motility. Results: CCK-8 assay, colony formation assay and EdU assay revealed that lncRNAs (ENST00000537266 and ENST00000426615 could inhibit cell proliferation. Cell cycle analysis showed that cell proportion was statistically significant increased in G1 phase and decreased in S phase and G2 phase in Si-266 transfected TPC-1 cells. In addition, a noteworthy increase of cell proportion in G1 phase accompanied by a decrease in S phase and unchanged G2 phase in Si-615 transfected TPC-1 cells were also observed. Meanwhile, transwell and scratch assay showed that ENST00000426615 could inhibit the cell motility while ENST00000537266 could not. Conclusion: Our results showed that lncRNAs (ENST00000426615 and ENST00000537266 might be important regulators of PTC cell proliferation and motility, which might provide new insight into the understanding of PTC pathogenesis.

  11. Exposure to Music Alters Cell Viability and Cell Motility of Human Nonauditory Cells in Culture

    Science.gov (United States)

    Lestard, Nathalia R.

    2016-01-01

    Although music is part of virtually all cultures in the world, little is known about how it affects us. Since the beginning of this century several studies suggested that the response to music, and to sound in general, is complex and might not be exclusively due to emotion, given that cell types other than auditory hair cells can also directly react to audible sound. The present study was designed to better understand the direct effects of acoustic vibrations, in the form of music, in human cells in culture. Our results suggest that the mechanisms of cell growth arrest and/or cell death induced by acoustic vibrations are similar for auditory and nonauditory cells. PMID:27478480

  12. Exposure to Music Alters Cell Viability and Cell Motility of Human Nonauditory Cells in Culture.

    Science.gov (United States)

    Lestard, Nathalia R; Capella, Marcia A M

    2016-01-01

    Although music is part of virtually all cultures in the world, little is known about how it affects us. Since the beginning of this century several studies suggested that the response to music, and to sound in general, is complex and might not be exclusively due to emotion, given that cell types other than auditory hair cells can also directly react to audible sound. The present study was designed to better understand the direct effects of acoustic vibrations, in the form of music, in human cells in culture. Our results suggest that the mechanisms of cell growth arrest and/or cell death induced by acoustic vibrations are similar for auditory and nonauditory cells. PMID:27478480

  13. Androgens Regulate T47D Cells Motility and Invasion through Actin Cytoskeleton Remodeling

    Science.gov (United States)

    Montt-Guevara, Maria Magdalena; Shortrede, Jorge Eduardo; Giretti, Maria Silvia; Giannini, Andrea; Mannella, Paolo; Russo, Eleonora; Genazzani, Alessandro David; Simoncini, Tommaso

    2016-01-01

    The relationship between androgens and breast cancer is controversial. Androgens have complex effects on breast cancer progression and metastasis. Moreover, androgen receptor (AR) is expressed in approximately 70 to 90% of invasive breast carcinomas, which has prognostic relevance in basal-like cancers and in triple-negative breast cancers. Recent studies have associated the actin-binding proteins of the ezrin–radixin–moesin (ERM) family with metastasis in endocrine-sensitive cancers. We studied on T47D breast cancer cells whether androgens with different characteristics, such as testosterone (T), dihydrotestosterone (DHT), and dehydroepiandrosterone (DHEA) may regulate breast cancer cell motility and invasion through the control of actin remodeling. We demonstrate that androgens promote migration and invasion in T47D via Moesin activation. We show that T and DHEA exert their actions via the AR and estrogen receptor (ER), while the non-aromatizable androgen – DHT – only recruits AR. We further report that androgen induced significant changes in actin organization with pseudopodia along with membrane ruffles formation, and this process is mediated by Moesin. Our work identifies novel mechanisms of action of androgens on breast cancer cells. Through the modulation of Moesin, androgens alter the architecture of cytoskeleton in T47D breast cancer cell and promote cell migration and invasion. These results could help to understand the biological actions of androgens on breast cancer and, eventually, to develop new strategies for breast cancer treatment. PMID:27746764

  14. 4D Tumorigenesis Model for Quantitating Coalescence, Directed Cell Motility and Chemotaxis, Identifying Unique Cell Behaviors, and Testing Anticancer Drugs.

    Science.gov (United States)

    Kuhl, Spencer; Voss, Edward; Scherer, Amanda; Lusche, Daniel F; Wessels, Deborah; Soll, David R

    2016-01-01

    A 4D high-resolution computer-assisted reconstruction and motion analysis system has been developed and applied to the long-term (14-30 days) analysis of cancer cells migrating and aggregating within a 3D matrix. 4D tumorigenesis models more closely approximate the tumor microenvironment than 2D substrates and, therefore, are improved tools for elucidating the interactions within the tumor microenvironment that promote growth and metastasis. The model we describe here can be used to analyze the growth of tumor cells, aggregate coalescence, directed cell motility and chemotaxis, matrix degradation, the effects of anticancer drugs, and the behavior of immune and endothelial cells mixed with cancer cells. The information given in this chapter is also intended to acquaint the reader with computer-assisted methods and algorithms that can be used for high-resolution 3D reconstruction and quantitative motion analysis. PMID:27271907

  15. Quantitative analysis of signal transduction in motile and phototactic cells by computerized light stimulation and model based tracking

    Science.gov (United States)

    Streif, Stefan; Staudinger, Wilfried Franz; Oesterhelt, Dieter; Marwan, Wolfgang

    2009-02-01

    To investigate the responses of Halobacterium salinarum to stimulation with light (phototaxis and photokinesis), we designed an experimental setup consisting of optical devices for automatic video image acquisition and computer-controlled light stimulation, and developed algorithms to analyze physiological responses of the cells. Cells are categorized as motile and nonmotile by a classification scheme based on the square displacement of cell positions. Computerized tracking based on a dynamic model of the stochastic cell movement and a Kalman filter-based algorithm allows smoothed estimates of the cell tracks and the detection of physiological responses to complex stimulus patterns. The setup and algorithms were calibrated which allows quantitative measurements and systematic analysis of cellular sensing and response. Overall, the setup is flexible, extensible, and consists mainly of commercially available products. This facilitates modifications of the setup and algorithms for physiological studies of the motility of cells or microorganisms.

  16. Cell motility and biofilm formation in Bacillus subtilis are affected by the ribosomal proteins, S11 and S21.

    Science.gov (United States)

    Takada, Hiraku; Morita, Masato; Shiwa, Yuh; Sugimoto, Ryoma; Suzuki, Shota; Kawamura, Fujio; Yoshikawa, Hirofumi

    2014-01-01

    Bacillus subtilis differentiates into various cellular states in response to environmental changes. It exists in two states during the exponential growth phase: motile cells and connected chains of sessile cells. Here, we identified new regulators of cell motility and chaining, the ribosomal proteins S21 (rpsU) and S11 (rpsK). Their mutants showed impaired cell motility (observed in a laboratory strain) and robust biofilm formation (observed in an undomesticated strain). The two major operons for biofilm formation, tapA-sipW-tasA and epsA-O, were strongly expressed in the rpsU mutant, whereas the flagellin-encoding hag gene and other SigD-dependent motility regulons were not. Genetic analysis revealed that the mutation of remA, the transcriptional activator of the eps operon, is epistatic to that of rpsU, whereas the mutation of antagonistic regulators of SinR is not. Our studies demonstrate that S11 and S21 participate in the regulation of bistability via the RemA/RemB pathway.

  17. Modulation of intracellular calcium levels by calcium lactate affects colon cancer cell motility through calcium-dependent calpain.

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    Pasupathi Sundaramoorthy

    Full Text Available Cancer cell motility is a key phenomenon regulating invasion and metastasis. Focal adhesion kinase (FAK plays a major role in cellular adhesion and metastasis of various cancers. The relationship between dietary supplementation of calcium and colon cancer has been extensively investigated. However, the effect of calcium (Ca2+ supplementation on calpain-FAK-motility is not clearly understood. We sought to identify the mechanism of FAK cleavage through Ca2+ bound lactate (CaLa, its downstream signaling and role in the motility of human colon cancer cells. We found that treating HCT116 and HT-29 cells with CaLa immediately increased the intracellular Ca2+ (iCa2+ levels for a prolonged period of time. Ca2+ influx induced cleavage of FAK into an N-terminal FAK (FERM domain in a dose-dependent manner. Phosphorylated FAK (p-FAK was also cleaved in to its p-N-terminal FAK. CaLa increased colon cancer cells motility. Calpeptin, a calpain inhibitor, reversed the effects of CaLa on FAK and pFAK cleavage in both cancer cell lines. The cleaved FAK translocates into the nucleus and modulates p53 stability through MDM2-associated ubiquitination. CaLa-induced Ca2+ influx increased the motility of colon cancer cells was mediated by calpain activity through FAK and pFAK protein destabilization. In conclusion, these results suggest that careful consideration may be given in deciding dietary Ca2+ supplementation to patient undergoing treatment for metastatic cancer.

  18. Putrescine importer PlaP contributes to swarming motility and urothelial cell invasion in Proteus mirabilis.

    Science.gov (United States)

    Kurihara, Shin; Sakai, Yumi; Suzuki, Hideyuki; Muth, Aaron; Phanstiel, Otto; Rather, Philip N

    2013-05-31

    Previously, we reported that the speA gene, encoding arginine decarboxylase, is required for swarming in the urinary tract pathogen Proteus mirabilis. In addition, this previous study suggested that putrescine may act as a cell-to-cell signaling molecule (Sturgill, G., and Rather, P. N. (2004) Mol. Microbiol. 51, 437-446). In this new study, PlaP, a putative putrescine importer, was characterized in P. mirabilis. In a wild-type background, a plaP null mutation resulted in a modest swarming defect and slightly decreased levels of intracellular putrescine. In a P. mirabilis speA mutant with greatly reduced levels of intracellular putrescine, plaP was required for the putrescine-dependent rescue of swarming motility. When a speA/plaP double mutant was grown in the presence of extracellular putrescine, the intracellular levels of putrescine were greatly reduced compared with the speA mutant alone, indicating that PlaP functioned as the primary putrescine importer. In urothelial cell invasion assays, a speA mutant exhibited a 50% reduction in invasion when compared with wild type, and this defect could be restored by putrescine in a PlaP-dependent manner. The putrescine analog Triamide-44 partially inhibited the uptake of putrescine by PlaP and decreased both putrescine stimulated swarming and urothelial cell invasion in a speA mutant.

  19. Multiple travelling-wave solutions in a minimal model for cell motility

    KAUST Repository

    Kimpton, L. S.

    2012-07-11

    Two-phase flow models have been used previously to model cell motility. In order to reduce the complexity inherent with describing the many physical processes, we formulate a minimal model. Here we demonstrate that even the simplest 1D, two-phase, poroviscous, reactive flow model displays various types of behaviour relevant to cell crawling. We present stability analyses that show that an asymmetric perturbation is required to cause a spatially uniform, stationary strip of cytoplasm to move, which is relevant to cell polarization. Our numerical simulations identify qualitatively distinct families of travellingwave solutions that coexist at certain parameter values. Within each family, the crawling speed of the strip has a bell-shaped dependence on the adhesion strength. The model captures the experimentally observed behaviour that cells crawl quickest at intermediate adhesion strengths, when the substrate is neither too sticky nor too slippy. © The Author 2012. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  20. Simulating the complex cell design of Trypanosoma brucei and its motility.

    Directory of Open Access Journals (Sweden)

    Davod Alizadehrad

    2015-01-01

    Full Text Available The flagellate Trypanosoma brucei, which causes the sleeping sickness when infecting a mammalian host, goes through an intricate life cycle. It has a rather complex propulsion mechanism and swims in diverse microenvironments. These continuously exert selective pressure, to which the trypanosome adjusts with its architecture and behavior. As a result, the trypanosome assumes a diversity of complex morphotypes during its life cycle. However, although cell biology has detailed form and function of most of them, experimental data on the dynamic behavior and development of most morphotypes is lacking. Here we show that simulation science can predict intermediate cell designs by conducting specific and controlled modifications of an accurate, nature-inspired cell model, which we developed using information from live cell analyses. The cell models account for several important characteristics of the real trypanosomal morphotypes, such as the geometry and elastic properties of the cell body, and their swimming mechanism using an eukaryotic flagellum. We introduce an elastic network model for the cell body, including bending rigidity and simulate swimming in a fluid environment, using the mesoscale simulation technique called multi-particle collision dynamics. The in silico trypanosome of the bloodstream form displays the characteristic in vivo rotational and translational motility pattern that is crucial for survival and virulence in the vertebrate host. Moreover, our model accurately simulates the trypanosome's tumbling and backward motion. We show that the distinctive course of the attached flagellum around the cell body is one important aspect to produce the observed swimming behavior in a viscous fluid, and also required to reach the maximal swimming velocity. Changing details of the flagellar attachment generates less efficient swimmers. We also simulate different morphotypes that occur during the parasite's development in the tsetse fly, and

  1. Geldanamycin inhibits proliferation and motility of Her2/neu-overexpressing SK-Br3 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    Ren Yu; Wang Ke; He Jianjun; Chen Wuke; Ma Qingyong

    2008-01-01

    Objective Benzoquinone ansamycin antibiotic, geldanamycin (GA), is a new anticancer agent that could inhibit Hsp90 by occupying its NH2-terminal ATP-binding site. This study was to investigate the antitumor efficacy of GA on Her2/neu tyrosine kinase overexpressing human breast cancer cell line SKBr3. Methods The degradation of Her2/neu tyrosine kinase was analyzed by Western blotting, the proliferation index was determined by MTT assay,cell cycle distribution was detected by flow cytometry, Cyclin D1 mRNA transcription was measured by RT-PCR and real-time PCR, and cell motility was evaluated by the cell culture insert model. Results GA induced a dose- and a time-dependent degradation of the Her2/neu tyrosine kinase protein and concurrently, the inhibition of cancer cell proliferation. The antitumor effects mediated by GA included: GA treatment decreased the survival rates of cancer cells,and led to a dase-dependent G1 arrest. Furthermore, this antitumor effect was proved to be related to declined transcription of Cyclin D1. Concurrently, the motility of cancer cells was reduced by GA. Conclusion GA treatment could induce the degradation of Her2/neu tyrnsine kinase efficiently, inhibit cancer cell proliferation and reduce motility in Her2/nen tyrosine kinase overexpressed human breast cancer cell line SKBr3.

  2. Up-regulation of METCAM/MUC18 promotes motility, invasion, and tumorigenesis of human breast cancer cells

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    Cai Shao-xi

    2011-03-01

    Full Text Available Abstract Background Conflicting research has identified METCAM/MUC18, an integral membrane cell adhesion molecule (CAM in the Ig-like gene super-family, as both a tumor promoter and a tumor suppressor in the development of breast cancer. To resolve this, we have re-investigated the role of this CAM in the progression of human breast cancer cells. Methods Three breast cancer cell lines were used for the tests: one luminal-like breast cancer cell line, MCF7, which did not express any METCAM/MUC18, and two basal-like breast cancer cell lines, MDA-MB-231 and MDA-MB-468, which expressed moderate levels of the protein. MCF7 cells were transfected with the human METCAM/MUC18 cDNA to obtain G418-resistant clones which expressed the protein and were used for testing effects of human METCAM/MUC18 expression on in vitro motility and invasiveness, and in vitro and in vivo tumorigenesis. Both MDA-MB-231 and MDA-MB-468 cells already expressed METCAM/MUC18. They were directly used for in vitro tests in the presence and absence of an anti-METCAM/MUC18 antibody. Results In MCF7 cells, enforced METCAM/MUC18 expression increased in vitro motility, invasiveness, anchorage-independent colony formation (in vitro tumorigenesis, and in vivo tumorigenesis. In both MDA-MB-231 and MDA-MB-468 cells, the anti-METCAM/MUC18 antibody inhibited both motility and invasiveness. Though both MDA-MB-231 and MDA-MB-468 cells established a disorganized growth in 3D basement membrane culture assay, the introduction of the anti-METCAM/MUC18 antibody completely destroyed their growth in the 3D culture. Conclusion These findings support the notion that human METCAM/MUC18 expression promotes the progression of human breast cancer cells by increasing their motility, invasiveness and tumorigenesis.

  3. Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment

    Science.gov (United States)

    Orcinha, Catarina; Münzner, Gert; Gerlach, Johannes; Kilias, Antje; Follo, Marie; Egert, Ulrich; Haas, Carola A.

    2016-01-01

    Granule cell dispersion (GCD) represents a pathological widening of the granule cell layer in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE). Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA) injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSCs) prepared from mice which express enhanced green fluorescent protein (eGFP) primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus, as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate toward the hilar region, where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3–6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together, these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons. PMID:27516734

  4. Seizure-induced motility of differentiated dentate granule cells is prevented by the central Reelin fragment

    Directory of Open Access Journals (Sweden)

    Catarina Orcinha

    2016-07-01

    Full Text Available Granule cell dispersion (GCD represents a pathological widening of the granule cell layer (GCL in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE. Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSC prepared from mice which express enhanced green fluorescent protein (eGFP primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate towards the hilar region where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3-6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons.

  5. Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment.

    Science.gov (United States)

    Orcinha, Catarina; Münzner, Gert; Gerlach, Johannes; Kilias, Antje; Follo, Marie; Egert, Ulrich; Haas, Carola A

    2016-01-01

    Granule cell dispersion (GCD) represents a pathological widening of the granule cell layer in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE). Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA) injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSCs) prepared from mice which express enhanced green fluorescent protein (eGFP) primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus, as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate toward the hilar region, where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3-6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together, these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons. PMID:27516734

  6. Cell motility dynamics: a novel segmentation algorithm to quantify multi-cellular bright field microscopy images.

    Directory of Open Access Journals (Sweden)

    Assaf Zaritsky

    Full Text Available Confocal microscopy analysis of fluorescence and morphology is becoming the standard tool in cell biology and molecular imaging. Accurate quantification algorithms are required to enhance the understanding of different biological phenomena. We present a novel approach based on image-segmentation of multi-cellular regions in bright field images demonstrating enhanced quantitative analyses and better understanding of cell motility. We present MultiCellSeg, a segmentation algorithm to separate between multi-cellular and background regions for bright field images, which is based on classification of local patches within an image: a cascade of Support Vector Machines (SVMs is applied using basic image features. Post processing includes additional classification and graph-cut segmentation to reclassify erroneous regions and refine the segmentation. This approach leads to a parameter-free and robust algorithm. Comparison to an alternative algorithm on wound healing assay images demonstrates its superiority. The proposed approach was used to evaluate common cell migration models such as wound healing and scatter assay. It was applied to quantify the acceleration effect of Hepatocyte growth factor/scatter factor (HGF/SF on healing rate in a time lapse confocal microscopy wound healing assay and demonstrated that the healing rate is linear in both treated and untreated cells, and that HGF/SF accelerates the healing rate by approximately two-fold. A novel fully automated, accurate, zero-parameters method to classify and score scatter-assay images was developed and demonstrated that multi-cellular texture is an excellent descriptor to measure HGF/SF-induced cell scattering. We show that exploitation of textural information from differential interference contrast (DIC images on the multi-cellular level can prove beneficial for the analyses of wound healing and scatter assays. The proposed approach is generic and can be used alone or alongside traditional

  7. Seizure-Induced Motility of Differentiated Dentate Granule Cells Is Prevented by the Central Reelin Fragment.

    Science.gov (United States)

    Orcinha, Catarina; Münzner, Gert; Gerlach, Johannes; Kilias, Antje; Follo, Marie; Egert, Ulrich; Haas, Carola A

    2016-01-01

    Granule cell dispersion (GCD) represents a pathological widening of the granule cell layer in the dentate gyrus and it is frequently observed in patients with mesial temporal lobe epilepsy (MTLE). Recent studies in human MTLE specimens and in animal epilepsy models have shown that a decreased expression and functional inactivation of the extracellular matrix protein Reelin correlates with GCD formation, but causal evidence is still lacking. Here, we used unilateral kainate (KA) injection into the mouse hippocampus, an established MTLE animal model, to precisely map the loss of reelin mRNA-synthesizing neurons in relation to GCD along the septotemporal axis of the epileptic hippocampus. We show that reelin mRNA-producing neurons are mainly lost in the hilus and that this loss precisely correlates with the occurrence of GCD. To monitor GCD formation in real time, we used organotypic hippocampal slice cultures (OHSCs) prepared from mice which express enhanced green fluorescent protein (eGFP) primarily in differentiated dentate granule cells. Using life cell microscopy we observed that increasing doses of KA resulted in an enhanced motility of eGFP-positive granule cells. Moreover, KA treatment of OHSC resulted in a rapid loss of Reelin-producing interneurons mainly in the hilus, as observed in vivo. A detailed analysis of the migration behavior of individual eGFP-positive granule cells revealed that the majority of these neurons actively migrate toward the hilar region, where Reelin-producing neurons are lost. Treatment with KA and subsequent addition of the recombinant R3-6 Reelin fragment significantly prevented the movement of eGFP-positive granule cells. Together, these findings suggest that GCD formation is indeed triggered by a loss of Reelin in hilar interneurons.

  8. Local ATP generation by brain-type creatine kinase (CK-B facilitates cell motility.

    Directory of Open Access Journals (Sweden)

    Jan W P Kuiper

    Full Text Available BACKGROUND: Creatine Kinases (CK catalyze the reversible transfer of high-energy phosphate groups between ATP and phosphocreatine, thereby playing a storage and distribution role in cellular energetics. Brain-type CK (CK-B deficiency is coupled to loss of function in neural cell circuits, altered bone-remodeling by osteoclasts and complement-mediated phagocytotic activity of macrophages, processes sharing dependency on actomyosin dynamics. METHODOLOGY/PRINCIPAL FINDINGS: Here, we provide evidence for direct coupling between CK-B and actomyosin activities in cortical microdomains of astrocytes and fibroblasts during spreading and migration. CK-B transiently accumulates in membrane ruffles and ablation of CK-B activity affects spreading and migration performance. Complementation experiments in CK-B-deficient fibroblasts, using new strategies to force protein relocalization from cytosol to cortical sites at membranes, confirmed the contribution of compartmentalized CK-B to cell morphogenetic dynamics. CONCLUSION/SIGNIFICANCE: Our results provide evidence that local cytoskeletal dynamics during cell motility is coupled to on-site availability of ATP generated by CK-B.

  9. B and T cell screen

    Science.gov (United States)

    Direct immunofluorescence; E-rosetting; T and B lymphocyte assays; B and T lymphocyte assays ... identifiers are added to distinguish between T and B cells. The E-rosetting test identifies T cells ...

  10. Cell_motility: a cross-platform, open source application for the study of cell motion paths

    Directory of Open Access Journals (Sweden)

    Gevaert Kris

    2006-06-01

    Full Text Available Abstract Background Migration is an important aspect of cellular behaviour and is therefore widely studied in cell biology. Numerous components are known to participate in this process in a highly dynamic manner. In order to obtain a better insight in cell migration, mutants or drugs are used and their motive phenotype is then linked with the disturbing factors. One of the typical approaches to study motion paths of individual cells relies on fitting mean square displacements to a persistent random walk function. Since the numerous calculations involved often rely on diverse commercial software packages, the analysis can be expensive, labour-intensive and error-prone work. Additionally, due to the nature of algorithms employed the calculations involved are not readily reproducible without access to the exact software package(s used. Results We here present the cell_motility software, an open source Java application under the GNU-GPL license that provides a clear and concise analysis workbench for large amounts of cell motion data. Apart from performing the necessary calculations, the software also visualizes the original motion paths as well as the results of the calculations to help the user interpret the data. The application features an intuitive graphical user interface as well as full user and developer documentation and both source and binary files can be freely downloaded from the project website at http://genesis.UGent.be/cell_motility . Conclusion In providing a free, open source software solution for the automated processing of cell motion data, we aim to achieve two important goals: labs can greatly simplify their data analysis pipeline as switching between different computational software packages becomes obsolete (thus reducing the chances for human error during data manipulation and transfer and secondly, to provide scientists in the field with a freely available common platform to perform their analyses, enabling more efficient

  11. Feverlike Temperature is a Virulence Regulatory Cue Controlling the Motility and Host Cell Entry of Typhoidal Salmonella

    OpenAIRE

    Elhadad, Dana; McClelland, Michael; Rahav, Galia; Gal-Mor, Ohad

    2014-01-01

    Human infection with typhoidal Salmonella serovars causes a febrile systemic disease, termed enteric fever. Here we establish that in response to a temperature equivalent to fever (39°C–42°C) Salmonella enterica serovars Typhi, Paratyphi A, and Sendai significantly attenuate their motility, epithelial cell invasion, and uptake by macrophages. Under these feverlike conditions, the residual epithelial cell invasion of S. Paratyphi A occurs in a type III secretion system (T3SS) 1–independent man...

  12. Slow motility in hair cells of the frog amphibian papilla: Myosin light chain-mediated shape change

    OpenAIRE

    Farahbakhsh, Nasser A.; Narins, Peter M.

    2008-01-01

    Using video, fluorescence and confocal microscopy, quantitative analysis and modeling, we investigated intracellular processes mediating the calcium/calmodulin (Ca2+/CaM)-dependent slow motility in hair cells dissociated from the rostral region of amphibian papilla, one of the two auditory organs in frogs. The time course of shape changes in these hair cells during the period of pretreatment with several specific inhibitors, as well as their response to the calcium ionophore, ionomycin, were ...

  13. The anti-motility signaling mechanism of TGFβ3 that controls cell traffic during skin wound healing

    Directory of Open Access Journals (Sweden)

    Arum Han

    2012-09-01

    When skin is wounded, migration of epidermal keratinocytes at the wound edge initiates within hours, whereas migration of dermal fibroblasts toward the wounded area remains undetectable until several days later. This “cell type traffic” regulation ensures proper healing of the wound, as disruptions of the regulation could either cause delay of wound healing or result in hypertrophic scars. TGFβ3 is the critical traffic controller that selectively halts migration of the dermal, but not epidermal, cells to ensure completion of wound re-epithelialization prior to wound remodeling. However, the mechanism of TGFβ3's anti-motility signaling has never been investigated. We report here that activated TβRII transmits the anti-motility signal of TGFβ3 in full to TβRI, since expression of the constitutively activated TβRI-TD mutant was sufficient to replace TGFβ3 to block PDGF-bb-induced dermal fibroblast migration. Second, the three components of R-Smad complex are all required. Individual downregulation of Smad2, Smad3 or Smad4 prevented TGFβ3 from inhibiting dermal fibroblast migration. Third, Protein Kinase Array allowed us to identify the protein kinase A (PKA as a specific downstream effector of R-Smads in dermal fibroblasts. Activation of PKA alone blocked PDGF-bb-induced dermal fibroblast migration, just like TGFβ3. Downregulation of PKA's catalytic subunit nullified the anti-motility signaling of TGFβ3. This is the first report on anti-motility signaling mechanism by TGFβ family cytokines. Significance of this finding is not only limited to wound healing but also to other human disorders, such as heart attack and cancer, where the diseased cells have often managed to avoid the anti-motility effect of TGFβ.

  14. Silibinin inhibits fibronectin induced motility, invasiveness and survival in human prostate carcinoma PC3 cells via targeting integrin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Deep, Gagan [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States); Kumar, Rahul; Jain, Anil K. [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); Agarwal, Chapla [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States); Agarwal, Rajesh, E-mail: Rajesh.agarwal@ucdenver.edu [Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Denver, Aurora, CO (United States); University of Colorado Cancer Center, University of Colorado Denver, Aurora, CO (United States)

    2014-10-15

    Highlights: • Silibinin inhibits fibronectin-induce motile morphology in PC3 cells. • Silibinin inhibits fibronectin-induced migration and invasion in PC3 cells. • Silibinin targets fibronectin-induced integrins and downstream signaling molecule. - Abstract: Prostate cancer (PCA) is the 2nd leading cause of cancer-related deaths among men in the United States. Preventing or inhibiting metastasis-related events through non-toxic agents could be a useful approach for lowering high mortality among PCA patients. We have earlier reported that natural flavonoid silibinin possesses strong anti-metastatic efficacy against PCA however, mechanism/s of its action still remains largely unknown. One of the major events during metastasis is the replacement of cell–cell interaction with integrins-based cell–matrix interaction that controls motility, invasiveness and survival of cancer cells. Accordingly, here we examined silibinin effect on advanced human PCA PC3 cells’ interaction with extracellular matrix component fibronectin. Silibinin (50–200 μM) treatment significantly decreased the fibronectin (5 μg/ml)-induced motile morphology via targeting actin cytoskeleton organization in PC3 cells. Silibinin also decreased the fibronectin-induced cell proliferation and motility but significantly increased cell death in PC3 cells. Silibinin also inhibited the PC3 cells invasiveness in Transwell invasion assays with fibronectin or cancer associated fibroblasts (CAFs) serving as chemoattractant. Importantly, PC3-luc cells cultured on fibronectin showed rapid dissemination and localized in lungs following tail vein injection in athymic male nude mice; however, in silibinin-treated PC3-luc cells, dissemination and lung localization was largely compromised. Molecular analyses revealed that silibinin treatment modulated the fibronectin-induced expression of integrins (α5, αV, β1 and β3), actin-remodeling (FAK, Src, GTPases, ARP2 and cortactin), apoptosis (cPARP and

  15. Membrane-bound steel factor maintains a high local concentration for mouse primordial germ cell motility, and defines the region of their migration.

    Directory of Open Access Journals (Sweden)

    Ying Gu

    Full Text Available Steel factor, the protein product of the Steel locus in the mouse, is a multifunctional signal for the primordial germ cell population. We have shown previously that its expression accompanies the germ cells during migration to the gonads, forming a "travelling niche" that controls their survival, motility, and proliferation. Here we show that these functions are distributed between the alternatively spliced membrane-bound and soluble forms of Steel factor. The germ cells normally migrate as individuals from E7.5 to E11.5, when they aggregate together in the embryonic gonads. Movie analysis of Steel-dickie mutant embryos, which make only the soluble form, at E7.5, showed that the germ cells fail to migrate normally, and undergo "premature aggregation" in the base of the allantois. Survival and directionality of movement is not affected. Addition of excess soluble Steel factor to Steel-dickie embryos rescued germ cell motility, and addition of Steel factor to germ cells in vitro showed that a fourfold higher dose was required to increase motility, compared to survival. These data show that soluble Steel factor is sufficient for germ cell survival, and suggest that the membrane-bound form provides a higher local concentration of Steel factor that controls the balance between germ cell motility and aggregation. This hypothesis was tested by addition of excess soluble Steel factor to slice cultures of E11.5 embryos, when migration usually ceases, and the germ cells aggregate. This reversed the aggregation process, and caused increased motility of the germ cells. We conclude that the two forms of Steel factor control different aspects of germ cell behavior, and that membrane-bound Steel factor controls germ cell motility within a "motility niche" that moves through the embryo with the germ cells. Escape from this niche causes cessation of motility and death by apoptosis of the ectopic germ cells.

  16. Multiple peptidoglycan modification networks modulate Helicobacter pylori's cell shape, motility, and colonization potential.

    Directory of Open Access Journals (Sweden)

    Laura K Sycuro

    Full Text Available Helical cell shape of the gastric pathogen Helicobacter pylori has been suggested to promote virulence through viscosity-dependent enhancement of swimming velocity. However, H. pylori csd1 mutants, which are curved but lack helical twist, show normal velocity in viscous polymer solutions and the reason for their deficiency in stomach colonization has remained unclear. Characterization of new rod shaped mutants identified Csd4, a DL-carboxypeptidase of peptidoglycan (PG tripeptide monomers and Csd5, a putative scaffolding protein. Morphological and biochemical studies indicated Csd4 tripeptide cleavage and Csd1 crosslinking relaxation modify the PG sacculus through independent networks that coordinately generate helical shape. csd4 mutants show attenuation of stomach colonization, but no change in proinflammatory cytokine induction, despite four-fold higher levels of Nod1-agonist tripeptides in the PG sacculus. Motility analysis of similarly shaped mutants bearing distinct alterations in PG modifications revealed deficits associated with shape, but only in gel-like media and not viscous solutions. As gastric mucus displays viscoelastic gel-like properties, our results suggest enhanced penetration of the mucus barrier underlies the fitness advantage conferred by H. pylori's characteristic shape.

  17. Oestrogen inhibits human colonic motility by a non-genomic cell membrane receptor-dependent mechanism.

    LENUS (Irish Health Repository)

    Hogan, A M

    2012-02-01

    BACKGROUND: Classical effects of oestrogen involve activation of target genes after binding nuclear receptors. Oestrogenic effects too rapid for DNA transcription (non-genomic) are known to occur. The effect of oestrogen on colonic motility is unknown despite the prevalence of gastrointestinal symptoms in pregnant and premenopausal women. METHODS: Histologically normal colon was obtained from proximal resection margins of colorectal carcinoma specimens. Circular smooth muscle strips were microdissected and suspended in organ baths under 1 g of tension. After equilibration, they were exposed to 17beta-oestradiol (n = 8) or bovine serum albumin (BSA)-conjugated 17beta-oestradiol (n = 8). Fulvestrant, an oestrogen receptor antagonist, was added to some baths (n = 8). Other strips were exposed to calphostin C or cycloheximide. Carbachol was added in increasing concentrations and contractile activity was recorded isometrically. RESULTS: Oestrogen inhibited colonic contractility (mean difference 19.7 per cent; n = 8, P < 0.001). In keeping with non-genomic, rapid-onset steroid action, the effect was apparent within minutes and reversible. It was observed with both 17beta-oestradiol and BSA-conjugated oestrogen, and was not altered by cycloheximide. Effects were inhibited by fulvestrant, suggesting receptor mediation. CONCLUSION: Oestrogen decreases contractility in human colonic smooth muscle by a non-genomic mechanism involving cell membrane coupling.

  18. THE DIFFERENTIAL REGULATION OF CELL MOTILE ACTIVITY THROUGH MATRIX STIFFNESS AND POROSITY IN THREE DIMENSIONAL COLLAGEN MATRICES

    Science.gov (United States)

    Miron-Mendoza, Miguel; Seemann, Joachim; Grinnell, Frederick

    2010-01-01

    In three dimensional collagen matrices, cell motile activity results in collagen translocation, cell spreading and cell migration. Cells can penetrate into the matrix as well as spread and migrate along its surface. In the current studies, we quantitatively characterize collagen translocation, cell spreading and cell migration in relationship to collagen matrix stiffness and porosity. Collagen matrices prepared with 1 to 4 mg/ml collagen exhibited matrix stiffness (storage modulus measured by oscillating rheometry) increasing from 4 to 60 Pa and matrix porosity (measured by scanning electron microscopy) decreasing from 4 to 1 μm2. Over this collagen concentration range, the consequences of cell motile activity changed markedly. As collagen concentration increased, cells no longer were able to cause translocation of collagen fibrils. Cell migration increased and cell spreading changed from dendritic to more flattened and polarized morphology depending on location of cells within or on the surface of the matrix. Collagen translocation appeared to depend primarily on matrix stiffness, whereas cell spreading and migration were less dependent on matrix stiffness and more dependent on collagen matrix porosity. PMID:20537378

  19. Apoptosis signal-regulating kinase 1 is involved in brain-derived neurotrophic factor (BDNF)-enhanced cell motility and matrix metalloproteinase 1 expression in human chondrosarcoma cells.

    Science.gov (United States)

    Lin, Chih-Yang; Chang, Sunny Li-Yun; Fong, Yi-Chin; Hsu, Chin-Jung; Tang, Chih-Hsin

    2013-07-25

    Chondrosarcoma is the primary malignancy of bone that is characterized by a potent capacity to invade locally and cause distant metastasis, and is therefore associated with poor prognoses. Chondrosarcoma further shows a predilection for metastasis to the lungs. The brain-derived neurotrophic factor (BDNF) is a small molecule in the neurotrophin family of growth factors that is associated with the disease status and outcome of cancers. However, the effect of BDNF on cell motility in human chondrosarcoma cells is mostly unknown. Here, we found that human chondrosarcoma cell lines had significantly higher cell motility and BDNF expression compared to normal chondrocytes. We also found that BDNF increased cell motility and expression of matrix metalloproteinase-1 (MMP-1) in human chondrosarcoma cells. BDNF-mediated cell motility and MMP-1 up-regulation were attenuated by Trk inhibitor (K252a), ASK1 inhibitor (thioredoxin), JNK inhibitor (SP600125), and p38 inhibitor (SB203580). Furthermore, BDNF also promoted Sp1 activation. Our results indicate that BDNF enhances the migration and invasion activity of chondrosarcoma cells by increasing MMP-1 expression through a signal transduction pathway that involves the TrkB receptor, ASK1, JNK/p38, and Sp1. BDNF thus represents a promising new target for treating chondrosarcoma metastasis.

  20. Silibinin inhibits fibronectin induced motility, invasiveness and survival in human prostate carcinoma PC3 cells via targeting integrin signaling.

    Science.gov (United States)

    Deep, Gagan; Kumar, Rahul; Jain, Anil K; Agarwal, Chapla; Agarwal, Rajesh

    2014-10-01

    Prostate cancer (PCA) is the 2nd leading cause of cancer-related deaths among men in the United States. Preventing or inhibiting metastasis-related events through non-toxic agents could be a useful approach for lowering high mortality among PCA patients. We have earlier reported that natural flavonoid silibinin possesses strong anti-metastatic efficacy against PCA however, mechanism/s of its action still remains largely unknown. One of the major events during metastasis is the replacement of cell-cell interaction with integrins-based cell-matrix interaction that controls motility, invasiveness and survival of cancer cells. Accordingly, here we examined silibinin effect on advanced human PCA PC3 cells' interaction with extracellular matrix component fibronectin. Silibinin (50-200 μM) treatment significantly decreased the fibronectin (5 μg/ml)-induced motile morphology via targeting actin cytoskeleton organization in PC3 cells. Silibinin also decreased the fibronectin-induced cell proliferation and motility but significantly increased cell death in PC3 cells. Silibinin also inhibited the PC3 cells invasiveness in Transwell invasion assays with fibronectin or cancer associated fibroblasts (CAFs) serving as chemoattractant. Importantly, PC3-luc cells cultured on fibronectin showed rapid dissemination and localized in lungs following tail vein injection in athymic male nude mice; however, in silibinin-treated PC3-luc cells, dissemination and lung localization was largely compromised. Molecular analyses revealed that silibinin treatment modulated the fibronectin-induced expression of integrins (α5, αV, β1 and β3), actin-remodeling (FAK, Src, GTPases, ARP2 and cortactin), apoptosis (cPARP and cleaved caspase 3), EMT (E-cadherin and β-catenin), and cell survival (survivin and Akt) related signaling molecules in PC3 cells. Furthermore, PC3-xenograft tissue analyses confirmed the inhibitory effect of silibinin on fibronectin and integrins expression. Together, these

  1. Screen printed interdigitated back contact solar cell

    Science.gov (United States)

    Baraona, C. R.; Mazaris, G. A.; Chai, A. T. (Inventor)

    1984-01-01

    Interdigitated back contact solar cells are made by screen printing dopant materials onto the back surface of a semiconductor substrate in a pair of interdigitated patterns. These dopant materials are then diffused into the substrate to form junctions having configurations corresponding to these patterns. Contacts having configurations which match the patterns are then applied over the junctions.

  2. Eukaryotic Translation Initiation Factor 3a (eIF3a) Promotes Cell Proliferation and Motility in Pancreatic Cancer.

    Science.gov (United States)

    Wang, Shu Qian; Liu, Yu; Yao, Min Ya; Jin, Jing

    2016-10-01

    Identifying a target molecule that is crucially involved in pancreatic tumor growth and metastasis is necessary in developing an effective treatment. The study aimed to investigate the role of the eukaryotic translation initiation factor 3a (eIF3a) in the cell proliferation and motility in pancreatic cancer. Our data showed that the expression of eIF3a was upregulated in pancreatic ductal adenocarcinoma as compared with its expression in normal pancreatic tissues. Knockdown of eIF3a by a specific shRNA caused significant decreases in cell proliferation and clonogenic abilities in pancreatic cancer SW1990 and Capan-1 cells. Consistently, the pancreatic cancer cell growth rates were also impaired in xenotransplanted mice. Moreover, wound-healing assay showed that depletion of eIF3a significantly slowed down the wound recovery processes in SW1990 and Capan-1 cells. Transwell migration and invasion assays further showed that cell migration and invasion abilities were significantly inhibited by knockdown of eIF3a in SW1990 and Capan-1 cells. Statistical analysis of eIF3a expression in 140 cases of pancreatic ductal adenocarcinoma samples revealed that eIF3a expression was significantly associated with tumor metastasis and TNM staging. These analyses suggest that eIF3a contributes to cell proliferation and motility in pancreatic ductal adenocarcinoma. PMID:27550487

  3. In Vitro Effect of Cell Phone Radiation on Motility, DNA Fragmentation and Clusterin Gene Expression in Human Sperm

    Directory of Open Access Journals (Sweden)

    Adel Zalata

    2015-04-01

    Full Text Available Background: Use of cellular phones emitting radiofrequency electromagnetic field (RF-EMF has been increased exponentially and become a part of everyday life. This study aimed to investigate the effects of in vitro RF-EMF exposure emitted from cellular phones on sperm motility index, sperm DNA fragmentation and seminal clusterin (CLU gene expression. Materials and Methods: In this prospective study, a total of 124 semen samples were grouped into the following main categories: i. normozoospermia (N, n=26, ii. asthenozoospermia (A, n=32, iii. asthenoteratozoospermia (AT, n=31 and iv. oligoasthenoteratozoospermia (OAT, n=35. The same semen samples were then divided into two portions non-exposed and exposed samples to cell phone radiation for 1 hour. Before and immediately after exposure, both aliquots were subjected to different assessments for sperm motility, acrosin activity, sperm DNA fragmentation and CLU gene expression. Statistical differences were analyzed using paired t student test for comparisons between two sub-groups where pAT>A>N groups, respectively (p<0.05. Conclusion: Cell phone emissions have a negative impact on exposed sperm motility index, sperm acrosin activity, sperm DNA fragmentation and seminal CLU gene expression, especially in OAT cases.

  4. Triterpene glycoside cucumarioside A(2)-2 from sea cucumber stimulates mouse immune cell adhesion, spreading, and motility.

    Science.gov (United States)

    Aminin, Dmitry L; Gorpenchenko, Tatyana Y; Bulgakov, Viktor P; Andryjashchenko, Polina V; Avilov, Sergey A; Kalinin, Vladimir I

    2011-06-01

    Holothurian triterpene glycosides are known to possess multiple biological activities. Here we show that cucumarioside A(2)-2 from the Far-Eastern edible holothurian Cucumaria japonica possesses potent immunomodulatory properties. The present studies were done to determine if cucumarioside A(2)-2 would affect macrophage adhesion, spreading, and motility. Resident peritoneal macrophages, collected from BALB/c mice, were exposed in vitro to low concentrations of cucumarioside A(2)-2 and compared with appropriate controls. Results indicate that 0.02 μg/mL cucumarioside A(2)-2 significantly enhanced macrophage morphology parameters and behavior. The glycoside stimulated these parameters by increasing the number of cells with increased adhesion properties as well as the spreading reaction and motility velocity by at least almost twofold. The data are discussed in terms of possible mechanisms underlying the immunomodulatory properties of cucumarioside A(2)-2. PMID:21554137

  5. Down-regulation of UDP-glucose dehydrogenase affects glycosaminoglycans synthesis and motility in HCT-8 colorectal carcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tsung-Pao; Pan, Yun-Ru; Fu, Chien-Yu; Chang, Hwan-You, E-mail: hychang@life.nthu.edu.tw

    2010-10-15

    UDP-glucose dehydrogenase (UGDH) catalyzes oxidation of UDP-glucose to yield UDP-glucuronic acid, a precursor of hyaluronic acid (HA) and other glycosaminoglycans (GAGs) in extracellular matrix. Although association of extracellular matrix with cell proliferation and migration has been well documented, the importance of UGDH in these behaviors is not clear. Using UGDH-specific small interference RNA to treat HCT-8 colorectal carcinoma cells, a decrease in both mRNA and protein levels of UGDH, as well as the cellular UDP-glucuronic acid and GAG production was observed. Treatment of HCT-8 cells with either UGDH-specific siRNA or HA synthesis inhibitor 4-methylumbelliferone effectively delayed cell aggregation into multicellular spheroids and impaired cell motility in both three-dimensional collagen gel and transwell migration assays. The reduction in cell aggregation and migration rates could be restored by addition of exogenous HA. These results indicate that UGDH can regulate cell motility through the production of GAG. The enzyme may be a potential target for therapeutic intervention of colorectal cancers.

  6. Nuclear motility in glioma cells reveals a cell-line dependent role of various cytoskeletal components.

    Directory of Open Access Journals (Sweden)

    Alexa Kiss

    Full Text Available Nuclear migration is a general term for the movement of the nucleus towards a specific site in the cell. These movements are involved in a number of fundamental biological processes, such as fertilization, cell division, and embryonic development. Despite of its importance, the mechanism of nuclear migration is still poorly understood in mammalian cells. In order to shed light on the mechanical processes underlying nuclear movements, we adapted a micro-patterning based assay. C6 rat and U87 human glioma cells seeded on fibronectin patterns--thereby forced into a bipolar morphology--displayed oscillatory movements of the nucleus or the whole cell, respectively. We found that both the actomyosin system and microtubules are involved in the nuclear/cellular movements of both cell lines, but their contributions are cell-/migration-type specific. Dynein activity was necessary for nuclear migration of C6 cells but active myosin-II was dispensable. On the other hand, coupled nuclear and cellular movements of U87 cells were driven by actomyosin contraction. We explain these cell-line dependent effects by the intrinsic differences in the overall mechanical tension due to the various cytoskeletal elements inside the cell. Our observations showed that the movements of the nucleus and the centrosome are strongly correlated and display large variation, indicating a tight but flexible coupling between them. The data also indicate that the forces responsible for nuclear movements are not acting directly via the centrosome. Based on our observations, we propose a new model for nuclear oscillations in C6 cells in which dynein and microtubule dynamics are the main drivers of nuclear movements. This mechanism is similar to the meiotic nuclear oscillations of Schizosaccharomyces pombe and may be evolutionary conserved.

  7. Neutrophils lacking platelet-endothelial cell adhesion molecule-1 exhibit loss of directionality and motility in CXCR2-mediated chemotaxis.

    Science.gov (United States)

    Wu, Yue; Stabach, Paul; Michaud, Michael; Madri, Joseph A

    2005-09-15

    Time-lapsed videomicroscopy was used to study the migration of platelet-endothelial cell adhesion molecule-1-deficient (PECAM-1(-/-)) murine neutrophils undergoing chemotaxis in Zigmond chambers containing IL-8, KC, or fMLP gradients. PECAM-1(-/-) neutrophils failed to translocate up the IL-8, KC, and fMLP gradients. Significant reductions in cell motility and cell spreading were also observed in IL-8 or KC gradients. In wild-type neutrophils, PECAM-1 and F-actin were colocalized at the leading fronts of polarized cells toward the gradient. In contrast, in PECAM-1(-/-) neutrophils, although F-actin also localized to the leading front of migrating cells, F-actin polymerization was unstable, and cycling was remarkably increased compared with that of wild-type neutrophils. This may be due to the decreased cytokine-induced mobilization of the actin-binding protein, moesin, into the cytoskeleton of PECAM-1(-/-) neutrophils. PECAM-1(-/-) neutrophils also exhibited intracellularly dislocalized Src homology 2 domain containing phosphatase 1 (SHP-1) and had less IL-8-induced SHP-1 phosphatase activity. These results suggest that PECAM-1 regulates neutrophil chemotaxis by modulating cell motility and directionality, in part through its effects on SHP-1 localization and activation. PMID:16148090

  8. Regulation of Motility, Invasion and Metastatic Potential of Squamous Cell Carcinoma by 1,25D3

    Science.gov (United States)

    Ma, Yingyu; Yu, Wei-Dong; Su, Bing; Seshadri, Mukund; Luo, Wei; Trump, Donald L.; Johnson, Candace S.

    2012-01-01

    BACKGROUND 1,25D3, the active metabolite of vitamin D, has been shown to exhibit broad spectrum anti-tumor activity in xenograft animal models. However, its activity against metastatic disease has not been extensively investigated. METHODS Squamous cell carcinoma (SCC) or 1,25D3-resistant variant SCC-DR cells were treated with 1,25D3. Actin organization was examined by immunofluorescence assay. Cell migration was assessed by “wound” healing and chemotactic migration assay. Cell invasion was assessed by Matrigel-based invasion assay and in situ zymography. MMP-2 and MMP-9 expression and secretion was examined by immunoblot analysis and ELISA, respectively. E-cadherin expression was assessed by flow cytometry, immunoblot analysis and immunohistochemistry. Knockdown of E-cadherin was achieved by siRNA. Experimental metastasis mouse model was done by intravenous injection of tumor cells. Lung tumor development was assessed by magnetic resonance imaging, gross observation and histology. RESULTS SCC cellular morphology and actin organization were altered by 10 nM of 1,25D3. 1,25D3 inhibited SCC cell motility and invasion, which was associated with reduced expression and secretion of MMP-2 and MMP-9. 1,25D3 promoted the expression of E-cadherin. These findings were not observed in SCC-DR cells. Knock down of E-cadherin rescued 1,25D3-inhibited cell migration. Intravenous injection of SCC or SCC-DR cells resulted in the establishment of extensive pulmonary lesions in saline-treated C3H mice. Treatment with 1,25D3 resulted in a marked reduction in the formation of lung tumor colonies in animals injected with SCC but not SCC-DR cells. CONCLUSIONS 1,25D3 suppresses SCC cell motility, invasion and metastasis, partially through the promotion of E-cadherin-mediated cell-cell adhesion. PMID:22833444

  9. A versatile class of cell surface directional motors gives rise to gliding motility and sporulation in Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Morgane Wartel

    2013-12-01

    Full Text Available Eukaryotic cells utilize an arsenal of processive transport systems to deliver macromolecules to specific subcellular sites. In prokaryotes, such transport mechanisms have only been shown to mediate gliding motility, a form of microbial surface translocation. Here, we show that the motility function of the Myxococcus xanthus Agl-Glt machinery results from the recent specialization of a versatile class of bacterial transporters. Specifically, we demonstrate that the Agl motility motor is modular and dissociates from the rest of the gliding machinery (the Glt complex to bind the newly expressed Nfs complex, a close Glt paralogue, during sporulation. Following this association, the Agl system transports Nfs proteins directionally around the spore surface. Since the main spore coat polymer is secreted at discrete sites around the spore surface, its transport by Agl-Nfs ensures its distribution around the spore. Thus, the Agl-Glt/Nfs machineries may constitute a novel class of directional bacterial surface transporters that can be diversified to specific tasks depending on the cognate cargo and machinery-specific accessories.

  10. Estrogen Enhances the Cell Viability and Motility of Breast Cancer Cells through the ERα-ΔNp63-Integrin β4 Signaling Pathway.

    Directory of Open Access Journals (Sweden)

    Jar-Yi Ho

    Full Text Available Estrogen induces ERα-positive breast cancer aggressiveness via the promotion of cell proliferation and survival, the epithelial-mesenchymal transition, and stem-like properties. Integrin β4 signaling has been implicated in estrogen/ERα-induced tumorigenicity and anti-apoptosis; however, this signaling cascade poorly understood. ΔNp63, an N-terminally truncated isoform of the p63 transcription factor, functions as a transcription factor of integrinβ4 and therefore regulates cellular adhesion and survival. Therefore, the aim of the present study was to investigate the estrogen-induced interaction between ERα, ΔNp63 and integrin β4 in breast cancer cells. In ERα-positive MCF-7 cells, estrogen activated ERα transcription, which induced ΔNp63 expression. And ΔNp63 subsequently induced integrin β4 expression, which resulted in AKT phosphorylation and enhanced cell viability and motility. Conversely, there was no inductive effect of estrogen on ΔNp63-integrinβ4-AKT signaling or on cell viability and motility in ERα-negative MDA-MB-231 cells. ΔNp63 knockdown abolishes these estrogen-induced effects and reduces cell viability and motility in MCF-7 cells. Nevertheless, ΔNp63 knockdown also inhibited cell migration in MDA-MB-231 cells through reducing integrin β4 expression and AKT phosphorylation. In conclusion, estrogen enhances ERα-positive breast cancer cell viability and motility through activating the ERα-ΔNp63-integrin β4 signaling pathway to induce AKT phosphorylated activation. Those findings should be useful to elucidate the crosstalk between estrogen/ER signaling and ΔNp63 signaling and provide novel insights into the effects of estrogen on breast cancer progression.

  11. Local calcium elevation and cell elongation initiate guided motility in electrically stimulated osteoblast-like cells.

    Directory of Open Access Journals (Sweden)

    Nurdan Ozkucur

    Full Text Available BACKGROUND: Investigation of the mechanisms of guided cell migration can contribute to our understanding of many crucial biological processes, such as development and regeneration. Endogenous and exogenous direct current electric fields (dcEF are known to induce directional cell migration, however the initial cellular responses to electrical stimulation are poorly understood. Ion fluxes, besides regulating intracellular homeostasis, have been implicated in many biological events, including regeneration. Therefore understanding intracellular ion kinetics during EF-directed cell migration can provide useful information for development and regeneration. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the initial events during migration of two osteogenic cell types, rat calvarial and human SaOS-2 cells, exposed to strong (10-15 V/cm and weak (< or = 5 V/cm dcEFs. Cell elongation and perpendicular orientation to the EF vector occurred in a time- and voltage-dependent manner. Calvarial osteoblasts migrated to the cathode as they formed new filopodia or lamellipodia and reorganized their cytoskeleton on the cathodal side. SaOS-2 cells showed similar responses except towards the anode. Strong dcEFs triggered a rapid increase in intracellular calcium levels, whereas a steady state level of intracellular calcium was observed in weaker fields. Interestingly, we found that dcEF-induced intracellular calcium elevation was initiated with a local rise on opposite sides in calvarial and SaOS-2 cells, which may explain their preferred directionality. In calcium-free conditions, dcEFs induced neither intracellular calcium elevation nor directed migration, indicating an important role for calcium ions. Blocking studies using cadmium chloride revealed that voltage-gated calcium channels (VGCCs are involved in dcEF-induced intracellular calcium elevation. CONCLUSION/SIGNIFICANCE: Taken together, these data form a time scale of the morphological and physiological

  12. PKA and CDK5 can phosphorylate specific serines on the intracellular domain of podoplanin (PDPN) to inhibit cell motility.

    Science.gov (United States)

    Krishnan, Harini; Retzbach, Edward P; Ramirez, Maria I; Liu, Tong; Li, Hong; Miller, W Todd; Goldberg, Gary S

    2015-07-01

    Podoplanin (PDPN) is a transmembrane glycoprotein that promotes tumor cell migration, invasion, and cancer metastasis. In fact, PDPN expression is induced in many types of cancer. Thus, PDPN has emerged as a functionally relevant cancer biomarker and chemotherapeutic target. PDPN contains 2 intracellular serine residues that are conserved between species ranging from mouse to humans. Recent studies indicate that protein kinase A (PKA) can phosphorylate PDPN in order to inhibit cell migration. However, the number and identification of specific residues phosphorylated by PKA have not been defined. In addition, roles of other kinases that may phosphorylate PDPN to control cell migration have not been investigated. We report here that cyclin dependent kinase 5 (CDK5) can phosphorylate PDPN in addition to PKA. Moreover, results from this study indicate that PKA and CDK5 cooperate to phosphorylate PDPN on both intracellular serine residues to decrease cell motility. These results provide new insight into PDPN phosphorylation dynamics and the role of PDPN in cell motility. Understanding novel mechanisms of PDPN intracellular signaling could assist with designing novel targeted chemotherapeutic agents and procedures. PMID:25959509

  13. Silencing GFAP isoforms in astrocytoma cells disturbs laminin-dependent motility and cell adhesion

    NARCIS (Netherlands)

    Moeton, Martina; Kanski, Regina; Stassen, Oscar M J A; Sluijs, Jacqueline A; Geerts, Dirk; van Tijn, P.; Wiche, Gerhard; van Strien, Miriam E; Hol, Elly M

    2014-01-01

    Glial fibrillary acidic protein (GFAP) is an intermediate filament protein expressed in astrocytes and neural stem cells. The GFAP gene is alternatively spliced, and expression of GFAP is highly regulated during development, on brain damage, and in neurodegenerative diseases. GFAPα is the canonical

  14. Chicken primordial germ cell motility in response to stem cell factor sensing.

    Science.gov (United States)

    Srihawong, Thanida; Kuwana, Takashi; Siripattarapravat, Kannika; Tirawattanawanich, Chanin

    2015-01-01

    Avian primordial germ cells (PGCs) are destined to migrate a long distance from their extra embryonic region via the vascular system to the gonadal ridges where they form the germ cells. Although PGC migration is crucial for a genetic continuation to the next generation, the factors and mechanisms that control their migration remain largely unknown. In the present study the chemotactic effect of stem cell factor (SCF) was examined on chicken blood circulating PGCs (cPGC), employing 3D chemotaxis slides and time-lapsed imaging analyses as an in vitro study model. Upon in vitro exposure to an SCF gradient, 77.1% (54 out of 70) of cPGCs showed a clear response, of which 48.1% (26 out of 54) polarized with the consecutive formation of a persistent membrane protrusion and significant directional migration towards the gradient and the others showed transient membrane protrusions. In contrast, the controls and apparently SCF unresponsive cPGCs and c-kit-negative red blood cells (RBCs) showed only cytoplasmic cycling with random formations of membrane blebbing and no directional migration. Significant (p goat anti-mouse c-kit primary antibody, suggesting that the cPGCs were capable of SCF sensing and the potential involvement of SCF/c-kit in the chemotactic migration. Therefore, SCF is suggested to function as a chemoattractant in the migration of chicken cPGC. PMID:26864485

  15. Epidermal growth factor promotes a mesenchymal over an amoeboid motility of MDA-MB-231 cells embedded within a 3D collagen matrix

    Science.gov (United States)

    Geum, Dongil T.; Kim, Beum Jun; Chang, Audrey E.; Hall, Matthew S.; Wu, Mingming

    2016-01-01

    The receptor of epidermal growth factor (EGFR) critically regulates tumor cell invasion and is a potent therapeutic target for treatment of many types of cancers, including carcinomas and glioblastomas. It is known that EGF regulates cell motility when tumor cells are embedded within a 3D biomatrix. However, roles of EGF in modulating tumor cell motility phenotype are largely unknown. In this article, we report that EGF promotes a mesenchymal over an amoeboid motility phenotype using a malignant breast tumor cell line, MDA-MB-231, embedded within a 3D collagen matrix. Amoeboid cells are rounded in shape, while mesenchymal cells are elongated, and their migrations are governed by a distinctly different set of biomolecules. Using single cell tracking analysis, we also show that EGF promotes cell dissemination through a significant increase in cell persistence along with a moderate increase of speed. The increase of persistence is correlated with the increase of the percentage of the mesenchymal cells within the population. Our work reveals a novel role of microenvironmental cue, EGF, in modulating heterogeneity and plasticity of tumor cell motility phenotype. In addition, it suggests a potential visual cue for diagnosing invasive states of breast cancer cells. This work can be easily extended beyond breast cancer cells.

  16. Human epididymis protein 4 (HE4) plays a key role in ovarian cancer cell adhesion and motility

    International Nuclear Information System (INIS)

    Highlights: ► We generated stable transduced HE4 overexpression and knockdown cells. ► HE4 was associated with EOC cell adhesion and motility. ► HE4 might have some effects on activation of EGFR-MAPK signaling pathway. ► HE4 play an important role in EOC tumorigenicity. -- Abstract: Human epididymis protein 4 (HE4) is a novel and specific biomarker for epithelial ovarian cancer (EOC). We previously demonstrated that serum HE4 levels were significantly elevated in the majority of EOC patients but not in subjects with benign disease or healthy controls. However, the precise mechanism of HE4 protein function is unknown. In this study, we generated HE4-overexpressing SKOV3 cells and found that stably transduced cells promoted cell adhesion and migration. Knockdown of HE4 expression was achieved by stable transfection of SKOV3 cells with a construct encoding a short hairpin DNA directed against the HE4 gene. Correspondingly, the proliferation and spreading ability of HE4-expressed cells were inhibited by HE4 suppression. Mechanistically, impaired EGFR and Erk1/2 phosphorylation were observed in cells with HE4 knockdown. The phosphorylation was restored when the knockdown cells were cultured in conditioned medium containing HE4. Moreover, in vivo tumorigenicity showed that HE4 suppression markedly inhibited the growth of tumors. This suggests that expression of HE4 is associated with cancer cell adhesion, migration and tumor growth, which can be related to its effects on the EGFR-MAPK signaling pathway. Our results provide evidence of the cellular and molecular mechanisms that may underlie the motility-promoting role of HE4 in EOC progression. The role of HE4 as a target for gene-based therapy might be considered in future studies.

  17. Novel protein kinase D inhibitors cause potent arrest in prostate cancer cell growth and motility

    Directory of Open Access Journals (Sweden)

    Lazo John S

    2010-05-01

    Full Text Available Abstract Background Protein kinase D (PKD has been implicated in a wide range of cellular processes and pathological conditions including cancer. However, targeting PKD therapeutically and dissecting PKD-mediated cellular responses remains difficult due to lack of a potent and selective inhibitor. Previously, we identified a novel pan-PKD inhibitor, CID755673, with potency in the upper nanomolar range and high selectivity for PKD. In an effort to further enhance its selectivity and potency for potential in vivo application, small molecule analogs of CID755673 were generated by modifying both the core structure and side-chains. Results After initial activity screening, five analogs with equal or greater potencies as CID755673 were chosen for further analysis: kb-NB142-70, kb-NB165-09, kb-NB165-31, kb-NB165-92, and kb-NB184-02. Our data showed that modifications to the aromatic core structure in particular significantly increased potency while retaining high specificity for PKD. When tested in prostate cancer cells, all compounds inhibited PMA-induced autophosphorylation of PKD1, with kb-NB142-70 being most active. Importantly, these analogs caused a dramatic arrest in cell proliferation accompanying elevated cytotoxicity when applied to prostate cancer cells. Cell migration and invasion were also inhibited by these analogs with varying potencies that correlated to their cellular activity. Conclusions Throughout the battery of experiments, the compounds kb-NB142-70 and kb-NB165-09 emerged as the most potent and specific analogs in vitro and in cells. These compounds are undergoing further testing for their effectiveness as pharmacological tools for dissecting PKD function and as potential anti-cancer agents in the treatment of prostate cancer.

  18. Cell motility and ECM proteolysis regulate tumor growth and tumor relapse by altering the fraction of cancer stem cells and their spatial scattering

    Science.gov (United States)

    Kumar, Sandeep; Kulkarni, Rahul; Sen, Shamik

    2016-06-01

    Tumors consist of multiple cell sub-populations including cancer stem cells (CSCs), transiently amplifying cells and terminally differentiated cells (TDCs), with the CSC fraction dictating the aggressiveness of the tumor and drug sensitivity. In epithelial cancers, tumor growth is influenced greatly by properties of the extracellular matrix (ECM), with cancer progression associated with an increase in ECM density. However, the extent to which increased ECM confinement induced by an increase in ECM density influences tumor growth and post treatment relapse dynamics remains incompletely understood. In this study, we use a cellular automata-based discrete modeling approach to study the collective influence of ECM density, cell motility and ECM proteolysis on tumor growth, tumor heterogeneity, and tumor relapse after drug treatment. We show that while increased confinement suppresses tumor growth and the spatial scattering of CSCs, this effect can be reversed when cells become more motile and proteolytically active. Our results further suggest that, in addition to the absolute number of CSCs, their spatial positioning also plays an important role in driving tumor growth. In a nutshell, our study suggests that, in confined environments, cell motility and ECM proteolysis are two key factors that regulate tumor growth and tumor relapse dynamics by altering the number and spatial distribution of CSCs.

  19. Diatom cell size, coloniality and motility: trade-offs between temperature, salinity and nutrient supply with climate change.

    Directory of Open Access Journals (Sweden)

    Filip Svensson

    Full Text Available Reduction in body size has been proposed as a universal response of organisms, both to warming and to decreased salinity. However, it is still controversial if size reduction is caused by temperature or salinity on their own, or if other factors interfere as well. We used natural benthic diatom communities to explore how "body size" (cells and colonies and motility change along temperature (2-26°C and salinity (0.5-7.8 gradients in the brackish Baltic Sea. Fourth-corner analysis confirmed that small cell and colony sizes were associated with high temperature in summer. Average community cell volume decreased linearly with 2.2% per °C. However, cells were larger with artificial warming when nutrient concentrations were high in the cold season. Average community cell volume increased by 5.2% per °C of artificial warming from 0 to 8.5°C and simultaneously there was a selection for motility, which probably helped to optimize growth rates by trade-offs between nutrient supply and irradiation. Along the Baltic Sea salinity gradient cell size decreased with decreasing salinity, apparently mediated by nutrient stoichiometry. Altogether, our results suggest that climate change in this century may polarize seasonality by creating two new niches, with elevated temperature at high nutrient concentrations in the cold season (increasing cell size and elevated temperature at low nutrient concentrations in the warm season (decreasing cell size. Higher temperature in summer and lower salinity by increased land-runoff are expected to decrease the average cell size of primary producers, which is likely to affect the transfer of energy to higher trophic levels.

  20. Atrazine represses S100A4 gene expression and TPA-induced motility in HepG2 cells.

    Science.gov (United States)

    Peyre, Ludovic; Zucchini-Pascal, Nathalie; Rahmani, Roger

    2014-03-01

    Atrazine (ATZ) is probably the most widely used herbicide in the world. However there are still many controversies regarding its impacts on human health. Our investigations on the role of pesticides in liver dysfunctions have led us to detect an inhibition of FSP1 expression of 70% at 50μm and around 95% at 500μM of ATZ (pEMT), a key step in the metastatic process. Here we investigated the possible effect of ATZ on cell migration and noticed that it prevents the EMT and motility of the HepG2 cells induced by the phorbol ester TPA. ATZ decreases Fak pathway activation but has no effect on the Erk1/2 pathway known to be involved in metastasis in this cell line. These results suggest that ATZ could be involved in cell homeostasis perturbation, potentially through a S100a4-dependant mechanism. PMID:24211529

  1. NG2 Proteoglycan Promotes Endothelial Cell Motility and Angiogenesis via Engagement of Galectin-3 and α3β1 Integrin

    Science.gov (United States)

    Fukushi, Jun-ichi; Makagiansar, Irwan T.; Stallcup, William B.

    2004-01-01

    The NG2 proteoglycan is expressed by microvascular pericytes in newly formed blood vessels. We have used in vitro and in vivo models to investigate the role of NG2 in cross-talk between pericytes and endothelial cells (EC). Binding of soluble NG2 to the EC surface induces cell motility and multicellular network formation in vitro and stimulates corneal angiogenesis in vivo. Biochemical data demonstrate the involvement of both galectin-3 and α3β1 integrin in the EC response to NG2 and show that NG2, galectin-3, and α3β1 form a complex on the cell surface. Transmembrane signaling via α3β1 is responsible for EC motility and morphogenesis in this system. Galectin-3–dependent oligomerization may potentiate NG2-mediated activation of α3β1. In conjunction with recent studies demonstrating the early involvement of pericytes in angiogenesis, these data suggest that pericyte-derived NG2 is an important factor in promoting EC migration and morphogenesis during the early stages of neovascularization. PMID:15181153

  2. Loss of ascl1a prevents secretory cell differentiation within the zebrafish intestinal epithelium resulting in a loss of distal intestinal motility.

    Science.gov (United States)

    Roach, Gillian; Heath Wallace, Rachel; Cameron, Amy; Emrah Ozel, Rifat; Hongay, Cintia F; Baral, Reshica; Andreescu, Silvana; Wallace, Kenneth N

    2013-04-15

    The vertebrate intestinal epithelium is renewed continuously from stem cells at the base of the crypt in mammals or base of the fold in fish over the life of the organism. As stem cells divide, newly formed epithelial cells make an initial choice between a secretory or enterocyte fate. This choice has previously been demonstrated to involve Notch signaling as well as Atonal and Her transcription factors in both embryogenesis and adults. Here, we demonstrate that in contrast to the atoh1 in mammals, ascl1a is responsible for formation of secretory cells in zebrafish. ascl1a-/- embryos lack all intestinal epithelial secretory cells and instead differentiate into enterocytes. ascl1a-/- embryos also fail to induce intestinal epithelial expression of deltaD suggesting that ascl1a plays a role in initiation of Notch signaling. Inhibition of Notch signaling increases the number of ascl1a and deltaD expressing intestinal epithelial cells as well as the number of developing secretory cells during two specific time periods: between 30 and 34hpf and again between 64 and 74hpf. Loss of enteroendocrine products results in loss of anterograde motility in ascl1a-/- embryos. 5HT produced by enterochromaffin cells is critical in motility and secretion within the intestine. We find that addition of exogenous 5HT to ascl1a-/- embryos at near physiological levels (measured by differential pulse voltammetry) induce anterograde motility at similar levels to wild type velocity, distance, and frequency. Removal or doubling the concentration of 5HT in WT embryos does not significantly affect anterograde motility, suggesting that the loss of additional enteroendocrine products in ascl1a-/- embryos also contributes to intestinal motility. Thus, zebrafish intestinal epithelial cells appear to have a common secretory progenitor from which all subtypes form. Loss of enteroendocrine cells reveals the critical need for enteroendocrine products in maintenance of normal intestinal motility.

  3. Control of human endometrial stromal cell motility by PDGF-BB, HB-EGF and trophoblast-secreted factors.

    Directory of Open Access Journals (Sweden)

    Maren Schwenke

    Full Text Available Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF triggered chemotaxis (directed locomotion, whereas platelet-derived growth factor (PDGF-BB elicited both chemotaxis and chemokinesis (non-directed locomotion of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating

  4. Feverlike Temperature is a Virulence Regulatory Cue Controlling the Motility and Host Cell Entry of Typhoidal Salmonella.

    Science.gov (United States)

    Elhadad, Dana; McClelland, Michael; Rahav, Galia; Gal-Mor, Ohad

    2015-07-01

    Human infection with typhoidal Salmonella serovars causes a febrile systemic disease, termed enteric fever. Here we establish that in response to a temperature equivalent to fever (39 °C-42 °C) Salmonella enterica serovars Typhi, Paratyphi A, and Sendai significantly attenuate their motility, epithelial cell invasion, and uptake by macrophages. Under these feverlike conditions, the residual epithelial cell invasion of S. Paratyphi A occurs in a type III secretion system (T3SS) 1-independent manner and results in restrained disruption of epithelium integrity. The impaired motility and invasion are associated with down-regulation of T3SS-1 genes and class II and III (but not I) of the flagella-chemotaxis regulon. In contrast, we demonstrate up-regulation of particular Salmonella pathogenicity island 2 genes (especially spiC) and increased intraepithelial growth in a T3SS-2-dependent manner. These results indicate that elevated physiological temperature is a novel cue controlling virulence phenotypes in typhoidal serovars, which is likely to play a role in the distinct clinical manifestations elicited by typhoidal and nontyphoidal salmonellae. PMID:25492917

  5. Knockdown of Rab5a expression decreases cancer cell motility and invasion through integrin-mediated signaling pathway

    Directory of Open Access Journals (Sweden)

    Shi Shu-liang

    2011-08-01

    Full Text Available Abstract Background Rab GTPases function as modulators in intracellular transport. Rab5a, a member of the Rab subfamily of small GTPases, is an important regulator of vesicle traffic from the plasma membrane to early endosomes. Recent findings have reported that Rab5a gene was involved in the progression of cancer. In the present study, we investigated the effect of Rab5a on cervical cancer invasion and metastasis and the molecular mechanism underlying the involvement of Rab5a. Methods Rab5a expression was assessed by immunohistochemical analysis on a cervical cancer tissue microarray. RNA interference (RNAi was performed to knock down the endogenous expression of Rab5a gene in HeLa and SiHa cells. Cell motility was evaluated using invasion assay and wound migration assay in vitro. The expression levels of integrin-associated molecules were detected by Western blot and immunofluorescence. Results We found that Rab5a was expressed at a high level in cervical cancer tissues. Silencing of Rab5a expression significantly decreased cancer cell motility and invasiveness. The down-regulation of integrin-associated focal adhesion signaling molecules was further detected in Rab5a knockdown cells. Meanwhile, active GTP-bound Rac1, Cdc42, and RhoA were also down-regulated, accompanied with the reduction in the number and size of filopodia and lamellipodia. Conclusions Taken together, these data suggest that Rab5a functions in regulating the invasion phenotype, and we propose that this regulation may be via integrin-mediated signaling pathway in cervical cancer cells.

  6. An extracellular matrix, calmodulin-binding protein from Dictyostelium with EGF-like repeats that enhance cell motility.

    Science.gov (United States)

    Suarez, Andres; Huber, Robert J; Myre, Michael A; O'Day, Danton H

    2011-07-01

    CyrA is a novel cysteine-rich protein with four EGFL repeats that was isolated using the calmodulin (CaM) binding overlay technique (CaMBOT), suggesting it is a CaM-binding protein (CaMBP). The full-length 63kDa cyrA is cleaved into two major C-terminal fragments, cyrA-C45 and cyrA-C40. A putative CaM-binding domain was detected and both CaM-agarose binding and CaM immunoprecipitation verified that cyrA-C45 and cyrA-C40 each bind to CaM in both a Ca(2+)-dependent and -independent manner. cyrA-C45 was present continuously throughout growth and development but was secreted at high levels during the multicellular slug stage of Dictyostelium development. At this time, cyrA localizes to the extracellular matrix (ECM). ECM purification verified the presence of cyrA-C45. An 18 amino acid peptide (DdEGFL1) from the first EGFL repeat sequence of cyrA (EGFL1) that is present in both cyrA-C45 and -C40 enhances both random cell motility and cAMP-mediated chemotaxis. Here we reveal that the dose-dependent enhancement of motility by DdEGFL1 is related to the time of cell starvation. Addition of DdEGFL1 also inhibits cyrA proteolysis. The status of cyrA as an extracellular CaMBP was further clarified by the demonstration that CaM is secreted during development. Antagonism of CaM with W7 resulted in enhanced cyrA proteolysis suggesting a functional role for extracellular CaM in protecting CaMBPs from proteolysis. cyrA is the first extracellular CaMBP identified in Dictyostelium and since it is an ECM protein with EGF-like repeats that enhance cell motility and it likely also represents the first matricellular protein identified in a lower eukaryote. PMID:21402150

  7. Ophiobolin A from Bipolaris oryzae Perturbs Motility and Membrane Integrities of Porcine Sperm and Induces Cell Death on Mammalian Somatic Cell Lines

    Directory of Open Access Journals (Sweden)

    Ottó Bencsik

    2014-09-01

    Full Text Available Bipolaris oryzae is a phytopathogenic fungus causing a brown spot disease in rice, and produces substance that strongly perturbs motility and membrane integrities of boar spermatozoa. The substance was isolated from the liquid culture of the fungal strain using extraction and a multi-step semi-preparative HPLC procedures. Based on the results of mass spectrometric and 2D NMR techniques, the bioactive molecule was identified as ophiobolin A, a previously described sesterterpene-type compound. The purified ophiobolin A exhibited strong motility inhibition and viability reduction on boar spermatozoa. Furthermore, it damaged the sperm mitochondria significantly at sublethal concentration by the dissipation of transmembrane potential in the mitochondrial inner membrane, while the plasma membrane permeability barrier remained intact. The study demonstrated that the cytotoxicity of ophiobolin A toward somatic cell lines is higher by 1–2 orders of magnitude compared to other mitochondriotoxic mycotoxins, and towards sperm cells unique by replacing the progressive motility by shivering tail beating at low exposure concentration.

  8. The hippo pathway effector YAP regulates motility, invasion, and castration-resistant growth of prostate cancer cells.

    Science.gov (United States)

    Zhang, Lin; Yang, Shuping; Chen, Xingcheng; Stauffer, Seth; Yu, Fang; Lele, Subodh M; Fu, Kai; Datta, Kaustubh; Palermo, Nicholas; Chen, Yuanhong; Dong, Jixin

    2015-04-01

    Yes-associated protein (YAP) is an effector of the Hippo tumor suppressor pathway. The functional significance of YAP in prostate cancer has remained elusive. In this study, we first show that enhanced expression of YAP is able to transform immortalized prostate epithelial cells and promote migration and invasion in both immortalized and cancerous prostate cells. We found that YAP mRNA was upregulated in androgen-insensitive prostate cancer cells (LNCaP-C81 and LNCaP-C4-2 cells) compared to the level in androgen-sensitive LNCaP cells. Importantly, ectopic expression of YAP activated androgen receptor signaling and was sufficient to promote LNCaP cells from an androgen-sensitive state to an androgen-insensitive state in vitro, and YAP conferred castration resistance in vivo. Accordingly, YAP knockdown greatly reduced the rates of migration and invasion of LNCaP-C4-2 cells and under androgen deprivation conditions largely blocked cell division in LNCaP-C4-2 cells. Mechanistically, we found that extracellular signal-regulated kinase-ribosomal s6 kinase signaling was downstream of YAP for cell survival, migration, and invasion in androgen-insensitive cells. Finally, immunohistochemistry showed significant upregulation and hyperactivation of YAP in castration-resistant prostate tumors compared to their levels in hormone-responsive prostate tumors. Together, our results identify YAP to be a novel regulator in prostate cancer cell motility, invasion, and castration-resistant growth and as a potential therapeutic target for metastatic castration-resistant prostate cancer (CRPC). PMID:25645929

  9. Quantitative analysis of Plasmodium ookinete motion in three dimensions suggests a critical role for cell shape in the biomechanics of malaria parasite gliding motility.

    Science.gov (United States)

    Kan, Andrey; Tan, Yan-Hong; Angrisano, Fiona; Hanssen, Eric; Rogers, Kelly L; Whitehead, Lachlan; Mollard, Vanessa P; Cozijnsen, Anton; Delves, Michael J; Crawford, Simon; Sinden, Robert E; McFadden, Geoffrey I; Leckie, Christopher; Bailey, James; Baum, Jake

    2014-05-01

    Motility is a fundamental part of cellular life and survival, including for Plasmodium parasites--single-celled protozoan pathogens responsible for human malaria. The motile life cycle forms achieve motility, called gliding, via the activity of an internal actomyosin motor. Although gliding is based on the well-studied system of actin and myosin, its core biomechanics are not completely understood. Currently accepted models suggest it results from a specifically organized cellular motor that produces a rearward directional force. When linked to surface-bound adhesins, this force is passaged to the cell posterior, propelling the parasite forwards. Gliding motility is observed in all three life cycle stages of Plasmodium: sporozoites, merozoites and ookinetes. However, it is only the ookinetes--formed inside the midgut of infected mosquitoes--that display continuous gliding without the necessity of host cell entry. This makes them ideal candidates for invasion-free biomechanical analysis. Here we apply a plate-based imaging approach to study ookinete motion in three-dimensional (3D) space to understand Plasmodium cell motility and how movement facilitates midgut colonization. Using single-cell tracking and numerical analysis of parasite motion in 3D, our analysis demonstrates that ookinetes move with a conserved left-handed helical trajectory. Investigation of cell morphology suggests this trajectory may be based on the ookinete subpellicular cytoskeleton, with complementary whole and subcellular electron microscopy showing that, like their motion paths, ookinetes share a conserved left-handed corkscrew shape and underlying twisted microtubular architecture. Through comparisons of 3D movement between wild-type ookinetes and a cytoskeleton-knockout mutant we demonstrate that perturbation of cell shape changes motion from helical to broadly linear. Therefore, while the precise linkages between cellular architecture and actomyosin motor organization remain unknown, our

  10. Unconventional Specimen Preparation Techniques Using High Resolution Low Voltage Field Emission Scanning Electron Microscopy to Study Cell Motility, Host Cell Invasion, and Internal Cell Structures in Toxoplasma gondii

    Science.gov (United States)

    Schatten, Heide; Ris, Hans

    2002-04-01

    Apicomplexan parasites employ complex and unconventional mechanisms for cell locomotion, host cell invasion, and cell division that are only poorly understood. While immunofluorescence and conventional transmission electron microscopy have been used to answer questions about the localization of some cytoskeletal proteins and cell organelles, many questions remain unanswered, partly because new methods are needed to study the complex interactions of cytoskeletal proteins and organelles that play a role in cell locomotion, host cell invasion, and cell division. The choice of fixation and preparation methods has proven critical for the analysis of cytoskeletal proteins because of the rapid turnover of actin filaments and the dense spatial organization of the cytoskeleton and its association with the complex membrane system. Here we introduce new methods to study structural aspects of cytoskeletal motility, host cell invasion, and cell division of Toxoplasma gondii, a most suitable laboratory model that is representative of apicomplexan parasites. The novel approach in our experiments is the use of high resolution low voltage field emission scanning electron microscopy (LVFESEM) combined with two new specimen preparation techniques. The first method uses LVFESEM after membrane extraction and stabilization of the cytoskeleton. This method allows viewing of actin filaments which had not been possible with any other method available so far. The second approach of imaging the parasite's ultrastructure and interactions with host cells uses semithick sections (200 nm) that are resin de-embedded (Ris and Malecki, 1993) and imaged with LVFESEM. This method allows analysis of structural detail in the parasite before and after host cell invasion and interactions with the membrane of the parasitophorous vacuole as well as parasite cell division.

  11. Slow motility in hair cells of the frog amphibian papilla: myosin light chain-mediated shape change.

    Science.gov (United States)

    Farahbakhsh, Nasser A; Narins, Peter M

    2008-07-01

    Using video, fluorescence and confocal microscopy, quantitative analysis and modeling, we investigated intracellular processes mediating the calcium/calmodulin (Ca(2+)/CaM)-dependent slow motility in hair cells dissociated from the rostral region of amphibian papilla, one of the two auditory organs in frogs. The time course of shape changes in these hair cells during the period of pretreatment with several specific inhibitors, as well as their response to the calcium ionophore, ionomycin, were recorded and compared. These cells respond to ionomycin with a tri-phasic shape change: an initial phase of iso-volumetric length decrease; a period of concurrent shortening and swelling; and the final phase of increase in both length and volume. We found that both the myosin light chain kinase inhibitor, ML-7, and antagonists of the multifunctional Ca(2+)/CaM-dependent kinases, KN-62 and KN-93, inhibit the iso-volumetric shortening phase of the response to ionomycin. The type 1 protein phosphatase inhibitors, calyculin A and okadaic acid induce minor shortening on their own, but do not significantly alter phase 1 response. However, they appear to counter effects of the inhibitors of Ca(2+)/CaM-dependent kinases. We hypothesize that an active actomyosin-based process mediates the iso-volumetric shortening in the frog rostral amphibian papillar hair cells.

  12. Fibroblasts Cultured on Nanowires Exhibit Low Motility, Impaired Cell Division, and DNA Damage

    DEFF Research Database (Denmark)

    Persson, H.; Købler, Carsten; Mølhave, Kristian;

    2013-01-01

    Mouse fibroblasts cultured on 7-μm-long vertical nanowires are reported on page 4006 by C. N. Prinz and co-workers. Culturing cells on this kind of substrate interferes greatly with cell function, causing the cells to develop into widely different morphologies. The cells' division is impaired...

  13. Transposon insertions of magellan-4 that impair social gliding motility in Myxococcus xanthus.

    Science.gov (United States)

    Youderian, Philip; Hartzell, Patricia L

    2006-03-01

    Myxococcus xanthus has two different mechanisms of motility, adventurous (A) motility, which permits individual cells to glide over solid surfaces, and social (S) motility, which permits groups of cells to glide. To identify the genes involved in S-gliding motility, we mutagenized a delta aglU (A-) strain with the defective transposon, magellan-4, and screened for S- mutants that form nonmotile colonies. Sequence analysis of the sites of the magellan-4 insertions in these mutants and the alignment of these sites with the M. xanthus genome sequence show that two-thirds of these insertions lie within 27 of the 37 nonessential genes known to be required for social motility, including those necessary for the biogenesis of type IV pili, exopolysaccharide, and lipopolysaccharide. The remaining insertions also identify 31 new, nonessential genes predicted to encode both structural and regulatory determinants of S motility. These include three tetratricopeptide repeat proteins, several regulators of transcription that may control the expression of genes involved in pilus extension and retraction, and additional enzymes involved in polysaccharide metabolism. Three insertions that abolish S motility lie within genes predicted to encode glycolytic enzymes, suggesting that the signal for pilus retraction may be a simple product of exopolysaccharide catabolism.

  14. Raft-dependent endocytosis of autocrine motility factor/phosphoglucose isomerase: a potential drug delivery route for tumor cells.

    Directory of Open Access Journals (Sweden)

    Liliana D Kojic

    Full Text Available BACKGROUND: Autocrine motility factor/phosphoglucose isomerase (AMF/PGI is the extracellular ligand for the gp78/AMFR receptor overexpressed in a variety of human cancers. We showed previously that raft-dependent internalization of AMF/PGI is elevated in metastatic MDA-435 cells, but not metastatic, caveolin-1-expressing MDA-231 cells, relative to non-metastatic MCF7 and dysplastic MCF10A cells suggesting that it might represent a tumor cell-specific endocytic pathway. METHODOLOGY/PRINCIPAL FINDINGS: Similarly, using flow cytometry, we demonstrate that raft-dependent endocytosis of AMF/PGI is increased in metastatic HT29 cancer cells expressing low levels of caveolin-1 relative to metastatic, caveolin-1-expressing, HCT116 colon cells and non-metastatic Caco-2 cells. Therefore, we exploited the raft-dependent internalization of AMF/PGI as a potential tumor-cell specific targeting mechanism. We synthesized an AMF/PGI-paclitaxel conjugate and found it to be as efficient as free paclitaxel in inducing cytotoxicity and apoptosis in tumor cells that readily internalize AMF/PGI compared to tumor cells that poorly internalize AMF/PGI. Murine K1735-M1 and B16-F1 melanoma cells internalize FITC-conjugated AMF/PGI and are acutely sensitive to AMF/PGI-paclitaxel mediated cytotoxicity in vitro. Moreover, following in vivo intratumoral injection, FITC-conjugated AMF/PGI is internalized in K1735-M1 tumors. Intratumoral injection of AMF/PGI-paclitaxel induced significantly higher tumor regression compared to free paclitaxel, even in B16-F1 cells, known to be resistant to taxol treatment. Treatment with AMF/PGI-paclitaxel significantly prolonged the median survival time of tumor bearing mice. Free AMF/PGI exhibited a pro-survival role, reducing the cytotoxic effect of both AMF/PGI-paclitaxel and free paclitaxel suggesting that AMF/PGI-paclitaxel targets a pathway associated with resistance to chemotherapeutic agents. AMF/PGI-FITC uptake by normal murine spleen

  15. CHRNA5 as negative regulator of nicotine signaling in normal and cancer bronchial cells: effects on motility, migration and p63 expression.

    Science.gov (United States)

    Krais, Annette M; Hautefeuille, Agnès H; Cros, Marie-Pierre; Krutovskikh, Vladimir; Tournier, Jean-Marie; Birembaut, Philippe; Thépot, Amélie; Paliwal, Anupam; Herceg, Zdenko; Boffetta, Paolo; Brennan, Paul; Hainaut, Pierre L

    2011-09-01

    Genome-wide association studies have linked lung cancer risk with a region of chromosome 15q25.1 containing CHRNA3, CHRNA5 and CHRNB4 encoding α3, α5 and β4 subunits of nicotinic acetylcholine receptors (nAChR), respectively. One of the strongest associations was observed for a non-silent single-nucleotide polymorphism at codon 398 in CHRNA5. Here, we have used pharmacological (antagonists) or genetic (RNA interference) interventions to modulate the activity of CHRNA5 in non-transformed bronchial cells and in lung cancer cell lines. In both cell types, silencing CHRNA5 or inhibiting receptors containing nAChR α5 with α-conotoxin MII exerted a nicotine-like effect, with increased motility and invasiveness in vitro and increasing calcium influx. The effects on motility were enhanced by addition of nicotine but blocked by inhibiting CHRNA7, which encodes the homopentameric receptor α7 subunit. Silencing CHRNA5 also decreased the expression of cell adhesion molecules P120 and ZO-1 in lung cancer cells as well as the expression of DeltaNp63α in squamous cell carcinoma cell lines. These results demonstrate a role for CHRNA5 in modulating adhesion and motility in bronchial cells, as well as in regulating p63, a potential oncogene in squamous cell carcinoma. PMID:21586512

  16. Novel roles of the Na+/H+ exchanger NHE1 and the Na+,HCO3 - cotransporter NBCn1 in cell survival, proliferation and motility

    DEFF Research Database (Denmark)

    Thorup, Gitte Ehrenreich

    knowledge on the regulation and roles of acid extruding transporters in cell survival, proliferation and motility. Finally, it is interesting from both a clinical and a basic research perspective that two functionally similar transporters, perhaps through different localization or interaction partners, have......Due to a shift towards glycolytic metabolism requiring increased capacity for acid extrusion, tumor cells upregulate acid extruding transport proteins. Dysregulation of pH regulatory ion transporters has been assigned important roles in tumor growth, cell survival/death balance, proliferation...... and cell motility. The molecular mechanisms contributing to altered pHi regulation in cancer cells are incomplete understood. Overexpression of ErbB2 is common in breast cancer and the expression of an N-terminally truncated, constitutively active ErbB2 receptor (ΔNErbB2) is associated with increased...

  17. Parathyroid Hormone Induces Bone Cell Motility and Loss of Mature Osteocyte Phenotype through L-Calcium Channel Dependent and Independent Mechanisms.

    Directory of Open Access Journals (Sweden)

    Matthew Prideaux

    Full Text Available Parathyroid Hormone (PTH can exert both anabolic and catabolic effects on the skeleton, potentially through expression of the PTH type1 receptor (PTH1R, which is highly expressed in osteocytes. To determine the cellular and molecular mechanisms responsible, we examined the effects of PTH on osteoblast to osteocyte differentiation using primary osteocytes and the IDG-SW3 murine cell line, which differentiate from osteoblast to osteocyte-like cells in vitro and express GFP under control of the dentin matrix 1 (Dmp1 promoter. PTH treatment resulted in an increase in some osteoblast and early osteocyte markers and a decrease in mature osteocyte marker expression. The gene expression profile of PTH-treated Day 28 IDG-SW3 cells was similar to PTH treated primary osteocytes. PTH treatment induced striking changes in the morphology of the Dmp1-GFP positive cells in IDG-SW3 cultures and primary cells from Dmp1-GFP transgenic mice. The cells changed from a more dendritic to an elongated morphology and showed increased cell motility. E11/gp38 has been shown to be important for cell migration, however, deletion of the E11/gp38/podoplanin gene had no effect on PTH-induced motility. The effects of PTH on motility were reproduced using cAMP, but not with protein kinase A (PKA, exchange proteins activated by cAMP (Epac, protein kinase C (PKC or phosphatidylinositol-4,5-bisphosphonate 3-kinase (Pi3K agonists nor were they blocked by their antagonists. However, the effects of PTH were mediated through calcium signaling, specifically through L-type channels normally expressed in osteoblasts but decreased in osteocytes. PTH was shown to increase expression of this channel, but decrease the T-type channel that is normally more highly expressed in osteocytes. Inhibition of L-type calcium channel activity attenuated the effects of PTH on cell morphology and motility but did not prevent the downregulation of mature osteocyte marker expression. Taken together, these

  18. Rapid actions of plasma membrane estrogen receptors regulate motility of mouse embryonic stem cells through a profilin-1/cofilin-1-directed kinase signaling pathway.

    Science.gov (United States)

    Yun, Seung Pil; Ryu, Jung Min; Kim, Mi Ok; Park, Jae Hong; Han, Ho Jae

    2012-08-01

    Long-term estrogen actions are vital for driving cell growth, but more recent evidence suggests that estrogen mediates more rapid cellular effects. However, the function of estradiol-17β (E(2))-BSA in mouse embryonic stem cells has not been reported. Therefore, we examined the role of E(2)-BSA in mouse embryonic stem cell motility and its related signal pathways. E(2)-BSA (10(-8) m) significantly increased motility after 24 h incubation and increased filamentous (F)-actin expression; these effects were inhibited by the estrogen receptor antagonist ICI 182,780, indicating that E(2)-BSA bound membrane estrogen receptors and initiated a signal. E(2)-BSA increased c-Src and focal adhesion kinase (FAK) phosphorylation, which was attenuated by ICI 182,780. The E(2)-BSA-induced increase in epidermal growth factor receptor (EGFR) phosphorylation was inhibited by Src inhibitor PP2. As a downstream signal molecule, E(2)-BSA activated cdc42 and increased formation of a complex with the neural Wiskott-Aldrich syndrome protein (N-WASP)/cdc42/transducer of cdc42-dependent actin assembly-1 (TOCA-1), which was inhibited by FAK small interfering RNA (siRNA) and EGFR inhibitor AG 1478. In addition, E(2)-BSA increased profilin-1 expression and cofilin-1 phosphorylation, which was blocked by cdc42 siRNA. Subsequently, E(2)-BSA induced an increase in F-actin expression, and cell motility was inhibited by each signal pathway-related siRNA molecule or inhibitors but not by cofilin-1 siRNA. A combined treatment of cofilin-1 siRNA and E(2)-BSA increased F-actin expression and cell motility more than that of E(2)-BSA alone. These data demonstrate that E(2)-BSA stimulated motility by interacting with profilin-1/cofilin-1 and F-actin through FAK- and c-Src/EGFR transactivation-dependent N-WASP/cdc42/TOCA-1 complex.

  19. Correlation of energy-dependent cell cohesion with social motility in Myxococcus xanthus.

    OpenAIRE

    Shimkets, L J

    1986-01-01

    An agglutination assay was used to study cell cohesion in the myxobacterium Myxococcus xanthus. Vegetative cells agglutinated in the presence of the divalent cations Mg2+ and Ca2+. Agglutination was blocked by energy poisons that inhibit electron transport, uncouple oxidative phosphorylation, or inhibit the membrane-bound ATPase. However, energy was not required for the maintenance of cells in the multicellular aggregate. Cyanide, a strong inhibitor of agglutination, did not cause cells to di...

  20. Matriptase is required for the active form of hepatocyte growth factor induced Met, focal adhesion kinase and protein kinase B activation on neural stem/progenitor cell motility.

    Science.gov (United States)

    Fang, Jung-Da; Lee, Sheau-Ling

    2014-07-01

    Hepatocyte growth factor (HGF) is a chemoattractant and inducer for neural stem/progenitor (NS/P) cell migration. Although the type II transmembrane serine protease, matriptase (MTP) is an activator of the latent HGF, MTP is indispensable on NS/P cell motility induced by the active form of HGF. This suggests that MTP's action on NS/P cell motility involves mechanisms other than proteolytic activation of HGF. In the present study, we investigate the role of MTP in HGF-stimulated signaling events. Using specific inhibitors of phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt) or focal adhesion kinase (FAK), we demonstrated that in NS/P cells HGF-activated c-Met induces PI3k-Akt signaling which then leads to FAK activation. This signaling pathway ultimately induces MMP2 expression and NS/P cell motility. Knocking down of MTP in NS/P cells with specific siRNA impaired HGF-stimulation of c-Met, Akt and FAK activation, blocked HGF-induced production of MMP2 and inhibited HGF-stimulated NS/P cell motility. MTP-knockdown NS/P cells cultured in the presence of recombinant protein of MTP protease domain or transfected with the full-length wild-type but not the protease-defected MTP restored HGF-responsive events in NS/P cells. In addition to functioning as HGF activator, our data revealed novel function of MTP on HGF-stimulated c-Met signaling activation.

  1. Cells as Active Particles in Asymmetric Potentials: Motility under External Gradients

    Science.gov (United States)

    Comelles, Jordi; Caballero, David; Voituriez, Raphaël; Hortigüela, Verónica; Wollrab, Viktoria; Godeau, Amélie Luise; Samitier, Josep; Martínez, Elena; Riveline, Daniel

    2014-01-01

    Cell migration is a crucial event during development and in disease. Mechanical constraints and chemical gradients can contribute to the establishment of cell direction, but their respective roles remain poorly understood. Using a microfabricated topographical ratchet, we show that the nucleus dictates the direction of cell movement through mechanical guidance by its environment. We demonstrate that this direction can be tuned by combining the topographical ratchet with a biochemical gradient of fibronectin adhesion. We report competition and cooperation between the two external cues. We also quantitatively compare the measurements associated with the trajectory of a model that treats cells as fluctuating particles trapped in a periodic asymmetric potential. We show that the cell nucleus contributes to the strength of the trap, whereas cell protrusions guided by the adhesive gradients add a constant tunable bias to the direction of cell motion. PMID:25296303

  2. Probabilistic Voxel-Fe model for single cell motility in 3D

    Science.gov (United States)

    Borau, Carlos; Polacheck, William J; Kamm, Roger D; García-Aznar, José Manuel

    2015-01-01

    Background Cells respond to a variety of external stimuli regulated by the environment conditions. Mechanical, chemical and biological factors are of great interest and have been deeply studied. Furthermore, mathematical and computational models have been rapidly growing over the past few years, permitting researches to run complex scenarios saving time and resources. Usually these models focus on specific features of cell migration, making them only suitable to study restricted phenomena. Methods Here we present a versatile finite element (FE) cell-scale 3D migration model based on probabilities depending in turn on ECM mechanical properties, chemical, fluid and boundary conditions. Results With this approach we are able to capture important outcomes of cell migration such as: velocities, trajectories, cell shape and aspect ratio, cell stress or ECM displacements. Conclusions The modular form of the model will allow us to constantly update and redefine it as advancements are made in clarifying how cellular events take place. PMID:26290806

  3. Inhibition of breast cancer cell motility with a non-cyclooxygenase inhibitory derivative of sulindac by suppressing TGFβ/miR-21 signaling.

    Science.gov (United States)

    Yi, Bin; Chang, Hong; Ma, Ruixia; Feng, Xiangling; Li, Wei; Piazza, Gary A; Xi, Yaguang

    2016-02-16

    Compelling efficacy on intervention of tumorigenesis by nonsteroidal anti-inflammatory drugs (NSAIDs) has been documented intensively. However, the toxicities related to cyclooxygenase (COX) inhibition resulting in suppression of physiologically important prostaglandins limit their clinical use for human cancer chemoprevention. A novel derivative of the NSAID sulindac sulfide (SS), referred as sulindac sulfide amide (SSA), was recently developed, which lacks COX inhibitory activity, yet shows greater suppressive effect than SS on growth of various cancer cells. In this study, we focus on the inhibitory activity of SSA on breast tumor cell motility, which has not been studied previously. Our results show that SSA treatment at non-cytotoxic concentrations can specifically reduce breast tumor cell motility without influencing tumor cell growth, and the mechanism of action involves the suppression of TGFβ signaling by directly blocking Smad2/3 phosphorylation. Moreover, miR-21, a well-documented oncogenic miRNA for promoting tumor cell metastasis, was also found to be involved in inhibitory activity of SSA in breast tumor cell motility through the modulation of TGFβ pathway. In conclusion, we demonstrate that a non-COX inhibitory derivative of sulindac can inhibit breast tumor metastasis by a mechanism involving the TGFβ/miR-21 signaling axis.

  4. Cell motility, morphology, viability and proliferation in response to nanotopography on silicon black.

    NARCIS (Netherlands)

    Łopacińska, Joanna M; Grǎdinaru, Cristian; Wierzbicki, Rafal; Købler, Carsten; Schmidt, Michael S; Madsen, Martin T; Skolimowski, Maciej; Dufva, Martin; Flyvbjerg, Henrik; Mølhave, Kristian

    2012-01-01

    Knowledge of cells' interactions with nanostructured materials is fundamental for bio-nanotechnology. We present results for how individual mouse fibroblasts from cell line NIH3T3 respond to highly spiked surfaces of silicon black that were fabricated by maskless reactive ion etching (RIE). We did s

  5. Cellular adhesome screen identifies critical modulators of focal adhesion dynamics, cellular traction forces and cell migration behaviour.

    Science.gov (United States)

    Fokkelman, Michiel; Balcıoğlu, Hayri E; Klip, Janna E; Yan, Kuan; Verbeek, Fons J; Danen, Erik H J; van de Water, Bob

    2016-01-01

    Cancer cells migrate from the primary tumour into surrounding tissue in order to form metastasis. Cell migration is a highly complex process, which requires continuous remodelling and re-organization of the cytoskeleton and cell-matrix adhesions. Here, we aimed to identify genes controlling aspects of tumour cell migration, including the dynamic organization of cell-matrix adhesions and cellular traction forces. In a siRNA screen targeting most cell adhesion-related genes we identified 200+ genes that regulate size and/or dynamics of cell-matrix adhesions in MCF7 breast cancer cells. In a subsequent secondary screen, the 64 most effective genes were evaluated for growth factor-induced cell migration and validated by tertiary RNAi pool deconvolution experiments. Four validated hits showed significantly enlarged adhesions accompanied by reduced cell migration upon siRNA-mediated knockdown. Furthermore, loss of PPP1R12B, HIPK3 or RAC2 caused cells to exert higher traction forces, as determined by traction force microscopy with elastomeric micropillar post arrays, and led to considerably reduced force turnover. Altogether, we identified genes that co-regulate cell-matrix adhesion dynamics and traction force turnover, thereby modulating overall motility behaviour. PMID:27531518

  6. Chlorotoxin Fused to IgG-Fc Inhibits Glioblastoma Cell Motility via Receptor-Mediated Endocytosis

    Directory of Open Access Journals (Sweden)

    Tomonari Kasai

    2012-01-01

    Full Text Available Chlorotoxin is a 36-amino acid peptide derived from Leiurus quinquestriatus (scorpion venom, which has been shown to inhibit low-conductance chloride channels in colonic epithelial cells. Chlorotoxin also binds to matrix metalloproteinase-2 and other proteins on glioma cell surfaces. Glioma cells are considered to require the activation of matrix metalloproteinase-2 during invasion and migration. In this study, for targeting glioma, we designed two types of recombinant chlorotoxin fused to human IgG-Fcs with/without a hinge region. Chlorotoxin fused to IgG-Fcs was designed as a dimer of 60 kDa with a hinge region and a monomer of 30 kDa without a hinge region. The monomeric and dimeric forms of chlorotoxin inhibited cell proliferation at 300 nM and induced internalization in human glioma A172 cells. The monomer had a greater inhibitory effect than the dimer; therefore, monomeric chlorotoxin fused to IgG-Fc was multivalently displayed on the surface of bionanocapsules to develop a drug delivery system that targeted matrix metalloproteinase-2. The target-dependent internalization of bionanocapsules in A172 cells was observed when chlorotoxin was displayed on the bionanocapsules. This study indicates that chlorotoxin fused to IgG-Fcs could be useful for the active targeting of glioblastoma cells.

  7. Cell motility regulation on a stepped micro pillar array device (SMPAD) with a discrete stiffness gradient.

    Science.gov (United States)

    Lee, Sujin; Hong, Juhee; Lee, Junghoon

    2016-02-28

    Our tissues consist of individual cells that respond to the elasticity of their environment, which varies between and within tissues. To better understand mechanically driven cell migration, it is necessary to manipulate the stiffness gradient across a substrate. Here, we have demonstrated a new variant of the microfabricated polymeric pillar array platform that can decouple the stiffness gradient from the ECM protein area. This goal is achieved via a "stepped" micro pillar array device (SMPAD) in which the contact area with the cell was kept constant while the diameter of the pillar bodies was altered to attain the proper mechanical stiffness. Using double-step SU-8 mold fabrication, the diameter of the top of every pillar was kept uniform, whereas that of the bottom was changed, to achieve the desired substrate rigidity. Fibronectin was immobilized on the pillar tops, providing a focal adhesion site for cells. C2C12, HeLa and NIH3T3 cells were cultured on the SMPAD, and the motion of the cells was observed by time-lapse microscopy. Using this simple platform, which produces a purely physical stimulus, we observed that various types of cell behavior are affected by the mechanical stimulus of the environment. We also demonstrated directed cell migration guided by a discrete rigidity gradient by varying stiffness. Interestingly, cell velocity was highest at the highest stiffness. Our approach enables the regulation of the mechanical properties of the polymeric pillar array device and eliminates the effects of the size of the contact area. This technique is a unique tool for studying cellular motion and behavior relative to various stiffness gradients in the environment. PMID:26787193

  8. Cell-free DNA screening and sex chromosome aneuploidies.

    Science.gov (United States)

    Mennuti, Michael T; Chandrasekaran, Suchitra; Khalek, Nahla; Dugoff, Lorraine

    2015-10-01

    Cell-free DNA (cfDNA) testing is increasingly being used to screen pregnant women for fetal aneuploidies. This technology may also identify fetal sex and can be used to screen for sex chromosome aneuploidies (SCAs). Physicians offering this screening will need to be prepared to offer comprehensive prenatal counseling about these disorders to an increasing number of patients. The purpose of this article is to consider the source of information to use for counseling, factors in parental decision-making, and the performance characteristics of cfDNA testing in screening for SCAs. Discordance between ultrasound examination and cfDNA results regarding fetal sex is also discussed.

  9. Autophagy Promotes Focal Adhesion Disassembly and Cell Motility of Metastatic Tumor Cells through the Direct Interaction of Paxillin with LC3.

    Science.gov (United States)

    Sharifi, Marina N; Mowers, Erin E; Drake, Lauren E; Collier, Chris; Chen, Hong; Zamora, Marta; Mui, Stephanie; Macleod, Kay F

    2016-05-24

    Autophagy is a conserved catabolic process that plays a housekeeping role in eliminating protein aggregates and organelles and is activated during nutrient deprivation to generate metabolites and energy. Autophagy plays a significant role in tumorigenesis, although opposing context-dependent functions of autophagy in cancer have complicated efforts to target autophagy for therapeutic purposes. We demonstrate that autophagy inhibition reduces tumor cell migration and invasion in vitro and attenuates metastasis in vivo. Numerous abnormally large focal adhesions (FAs) accumulate in autophagy-deficient tumor cells, reflecting a role for autophagy in FA disassembly through targeted degradation of paxillin. We demonstrate that paxillin interacts with processed LC3 through a conserved LIR motif in the amino-terminal end of paxillin and that this interaction is regulated by oncogenic SRC activity. Together, these data establish a function for autophagy in FA turnover, tumor cell motility, and metastasis. PMID:27184837

  10. An adhesion-dependent switch between mechanisms that determine motile cell shape.

    Directory of Open Access Journals (Sweden)

    Erin L Barnhart

    2011-05-01

    Full Text Available Keratocytes are fast-moving cells in which adhesion dynamics are tightly coupled to the actin polymerization motor that drives migration, resulting in highly coordinated cell movement. We have found that modifying the adhesive properties of the underlying substrate has a dramatic effect on keratocyte morphology. Cells crawling at intermediate adhesion strengths resembled stereotypical keratocytes, characterized by a broad, fan-shaped lamellipodium, clearly defined leading and trailing edges, and persistent rates of protrusion and retraction. Cells at low adhesion strength were small and round with highly variable protrusion and retraction rates, and cells at high adhesion strength were large and asymmetrical and, strikingly, exhibited traveling waves of protrusion. To elucidate the mechanisms by which adhesion strength determines cell behavior, we examined the organization of adhesions, myosin II, and the actin network in keratocytes migrating on substrates with different adhesion strengths. On the whole, our results are consistent with a quantitative physical model in which keratocyte shape and migratory behavior emerge from the self-organization of actin, adhesions, and myosin, and quantitative changes in either adhesion strength or myosin contraction can switch keratocytes among qualitatively distinct migration regimes.

  11. The neuronal differentiation factor NeuroD1 downregulates the neuronal repellent factor Slit2 expression and promotes cell motility and tumor formation of neuroblastoma.

    Science.gov (United States)

    Huang, Peng; Kishida, Satoshi; Cao, Dongliang; Murakami-Tonami, Yuko; Mu, Ping; Nakaguro, Masato; Koide, Naoshi; Takeuchi, Ichiro; Onishi, Akira; Kadomatsu, Kenji

    2011-04-15

    The basic helix-loop-helix transcription factor NeuroD1 has been implicated in the neurogenesis and early differentiation of pancreatic endocrine cells. However, its function in relation to cancer has been poorly examined. In this study, we found that NeuroD1 is involved in the tumorigenesis of neuroblastoma. NeuroD1 was strongly expressed in a hyperplastic region comprising neuroblasts in the celiac sympathetic ganglion of 2-week-old MYCN transgenic (Tg) mice and was consistently expressed in the subsequently generated neuroblastoma tissue. NeuroD1 knockdown by short hairpin RNA (shRNA) resulted in motility inhibition of the human neuroblastoma cell lines, and this effect was reversed by shRNA-resistant NeuroD1. The motility inhibition by NeuroD1 knockdown was associated with induction of Slit2 expression, and knockdown of Slit2 could restore cell motility. Consistent with this finding, shRNA-resistant NeuroD1 suppressed Slit2 expression. NeuroD1 directly bound to the first and second E-box of the Slit2 promoter region. Moreover, we found that the growth of tumor spheres, established from neuroblastoma cell lines in MYCN Tg mice, was suppressed by NeuroD1 suppression. The functions identified for NeuroD1 in cell motility and tumor sphere growth may suggest a link between NeuroD1 and the tumorigenesis of neuroblastoma. Indeed, tumor formation of tumor sphere-derived cells was significantly suppressed by NeuroD1 knockdown. These data are relevant to the clinical features of human neuroblastoma: high NeuroD1 expression was closely associated with poor prognosis. Our findings establish the critical role of the neuronal differentiation factor NeuroD1 in neuroblastoma as well as its functional relationship with the neuronal repellent factor Slit2.

  12. Substance-specific importance of EGFR for vascular smooth muscle cells motility in primary culture.

    Science.gov (United States)

    Schreier, Barbara; Schwerdt, Gerald; Heise, Christian; Bethmann, Daniel; Rabe, Sindy; Mildenberger, Sigrid; Gekle, Michael

    2016-07-01

    Besides their importance for the vascular tone, vascular smooth muscle cells (VSMC) also contribute to pathophysiological vessel alterations. Various G-protein coupled receptor ligands involved in vascular dysfunction and remodeling can transactivate the epidermal growth factor receptor (EGFR) of VSMC, yet the importance of EGFR transactivation for the VSMC phenotype is incompletely understood. The aims of this study were (i) to characterize further the importance of the VSMC-EGFR for proliferation, migration and marker gene expression for inflammation, fibrosis and reactive oxygen species (ROS) homeostasis and (ii) to test the hypothesis that vasoactive substances (endothelin-1, phenylephrine, thrombin, vasopressin and ATP) rely differentially on the EGFR with respect to the abovementioned phenotypic alterations. In primary, aortic VSMC from mice without conditional deletion of the EGFR, proliferation, migration, marker gene expression (inflammation, fibrosis and ROS homeostasis) and cell signaling (ERK 1/2, intracellular calcium) were analyzed. VSMC-EGFR loss reduced collective cell migration and single cell migration probability, while no difference between the genotypes in single cell velocity, chemotaxis or marker gene expression could be observed under control conditions. EGF promoted proliferation, collective cell migration, chemokinesis and chemotaxis and leads to a proinflammatory gene expression profile in wildtype but not in knockout VSMC. Comparing the impact of five vasoactive substances (all reported to transactivate EGFR and all leading to an EGFR dependent increase in ERK1/2 phosphorylation), we demonstrate that the importance of EGFR for their action is substance-dependent and most apparent for crowd migration but plays a minor role for gene expression regulation.

  13. WIP regulates persistence of cell migration and ruffle formation in both mesenchymal and amoeboid modes of motility.

    Directory of Open Access Journals (Sweden)

    Inmaculada Banon-Rodriguez

    Full Text Available The spatial distribution of signals downstream from receptor tyrosine kinases (RTKs or G-protein coupled receptors (GPCR regulates fundamental cellular processes that control cell migration and growth. Both pathways rely significantly on actin cytoskeleton reorganization mediated by nucleation-promoting factors such as the WASP-(Wiskott-Aldrich Syndrome Protein family. WIP (WASP Interacting Protein is essential for the formation of a class of polarised actin microdomain, namely dorsal ruffles, downstream of the RTK for PDGF (platelet-derived growth factor but the underlying mechanism is poorly understood. Using lentivirally-reconstituted WIP-deficient murine fibroblasts we define the requirement for WIP interaction with N-WASP (neural WASP and Nck for efficient dorsal ruffle formation and of WIP-Nck binding for fibroblast chemotaxis towards PDGF-AA. The formation of both circular dorsal ruffles in PDGF-AA-stimulated primary fibroblasts and lamellipodia in CXCL13-treated B lymphocytes are also compromised by WIP-deficiency. We provide data to show that a WIP-Nck signalling complex interacts with RTK to promote polarised actin remodelling in fibroblasts and provide the first evidence for WIP involvement in the control of migratory persistence in both mesenchymal (fibroblast and amoeboid (B lymphocytes motility.

  14. Proline-rich tyrosine kinase 2 (Pyk2 promotes cell motility of hepatocellular carcinoma through induction of epithelial to mesenchymal transition.

    Directory of Open Access Journals (Sweden)

    Chris K Sun

    Full Text Available AIMS: Proline-rich tyrosine kinase 2 (Pyk2, a non-receptor tyrosine kinase of the focal adhesion kinase (FAK family, is up-regulated in more than 60% of the tumors of hepatocellular carcinoma (HCC patients. Forced overexpression of Pyk2 can promote the proliferation and invasion of HCC cells. In this study, we aimed to explore the underlying molecular mechanism of Pyk2-mediated cell migration of HCC cells. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrated that Pyk2 transformed the epithelial HCC cell line Hep3B into a mesenchymal phenotype via the induction of epithelial to mesenchymal transition (EMT, signified by the up-regulation of membrane ruffle formation, activation of Rac/Rho GTPases, down-regulation of epithelial genes E-cadherin and cytokeratin as well as promotion of cell motility in presence of lysophosphatidic acid (LPA. Suppression of Pyk2 by overexpression of dominant negative PRNK domain in the metastatic HCC cell line MHCC97L transformed its fibroblastoid phenotype to an epithelial phenotype with up-regulation of epithelial genes, down-regulation of mesenchymal genes N-cadherin and STAT5b, and reduction of LPA-induced membrane ruffle formation and cell motility. Moreover, overexpression of Pyk2 in Hep3B cells promoted the phosphorylation and localization of mesenchymal gene Hic-5 onto cell membrane while suppression of Pyk2 in MHCC97L cells attenuated its phosphorylation and localization. CONCLUSION: These data provided new evidence of the underlying mechanism of Pyk2 in controlling cell motility of HCC cells through regulation of genes associated with EMT.

  15. Geldanamycin inhibits proliferation and motility of Her2/neu-overexpressing SKBr3 breast cancer cells

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Objective Benzoquinone ansamycin antibiotic, geldanamycin (GA), is a new anticancer agent that could inhibit Hsp90 by occupying its NH2-terminal ATP-binding site. This study was to investigate the antitumor efficacy of GA on Her2/neu tyrosine kinase overexpressing human breast cancer cell line SKBr3. Methods The degradation of Her2/neu tyrosine kinase was analyzed by Western blotting, the proliferation index was determined by MTT assay, cell cycle distribution was detected by flow cytometry, Cyclin D1 mRNA ...

  16. SpatTrack: an imaging toolbox for analysis of vesicle motility and distribution in living cells

    DEFF Research Database (Denmark)

    Lund, Frederik Wendelboe; Jensen, Marie Louise; Christensen, Tanja;

    2014-01-01

    The endocytic pathway is a complex network of highly dynamic organelles, which has been traditionally studied by quantitative fluorescence microscopy. The data generated by this method can be overwhelming and its analysis, even for the skilled microscopist, is tedious and error-prone. We developed...... SpatTrack, an open source, platform-independent program collecting a variety of methods for analysis of vesicle dynamics and distribution in living cells. SpatTrack performs 2D particle tracking, trajectory analysis and fitting of diffusion models to the calculated mean square displacement. It allows...... a subpopulation of late endosomes/lysosomes (LE/LYSs). This was paralleled by repositioning and active transport of NPC2-containing vesicles to the cell surface. The potential of SpatTrack for other applications in intracellular transport studies will be discussed....

  17. SH4-domain-induced plasma membrane dynamization promotes bleb-associated cell motility.

    Science.gov (United States)

    Tournaviti, Stella; Hannemann, Sebastian; Terjung, Stefan; Kitzing, Thomas M; Stegmayer, Carolin; Ritzerfeld, Julia; Walther, Paul; Grosse, Robert; Nickel, Walter; Fackler, Oliver T

    2007-11-01

    SH4 domains provide bipartite membrane-targeting signals for oncogenic Src family kinases. Here we report the induction of non-apoptotic plasma membrane (PM) blebbing as a novel and conserved activity of SH4 domains derived from the prototypic Src kinases Src, Fyn, Yes and Lck as well as the HASPB protein of Leishmania parasites. SH4-domain-induced blebbing is highly dynamic, with bleb formation and collapse displaying distinct kinetics. These reorganizations of the PM are controlled by Rho but not Rac or Cdc42 GTPase signalling pathways. SH4-induced membrane blebbing requires the membrane association of the SH4 domain, is regulated by the activities of Rock kinase and myosin II ATPase, and depends on the integrity of F-actin as well as microtubules. Endogenous Src kinase activity is crucial for PM blebbing in SH4-domain-expressing cells, active Src and Rock kinases are enriched in SH4-domain-induced PM blebs, and PM blebbing correlates with enhanced cell invasion in 3D matrices. These results establish a novel link between SH4 domains, Src activity and Rho signalling, and implicate SH4-domain-mediated PM dynamization as a mechanism that influences invasiveness of cells transformed by SH4-domain-containing oncoproteins. PMID:17959630

  18. SpatTrack: an imaging toolbox for analysis of vesicle motility and distribution in living cells.

    Science.gov (United States)

    Lund, Frederik W; Jensen, Maria Louise V; Christensen, Tanja; Nielsen, Gitte K; Heegaard, Christian W; Wüstner, Daniel

    2014-12-01

    The endocytic pathway is a complex network of highly dynamic organelles, which has been traditionally studied by quantitative fluorescence microscopy. The data generated by this method can be overwhelming and its analysis, even for the skilled microscopist, is tedious and error-prone. We developed SpatTrack, an open source, platform-independent program collecting a variety of methods for analysis of vesicle dynamics and distribution in living cells. SpatTrack performs 2D particle tracking, trajectory analysis and fitting of diffusion models to the calculated mean square displacement. It allows for spatial analysis of detected vesicle patterns including calculation of the radial distribution function and particle-based colocalization. Importantly, all analysis tools are supported by Monte Carlo simulations of synthetic images. This allows the user to assess the reliability of the analysis and to study alternative scenarios. We demonstrate the functionality of SpatTrack by performing a detailed imaging study of internalized fluorescence-tagged Niemann Pick C2 (NPC2) protein in human disease fibroblasts. Using SpatTrack, we show that NPC2 rescued the cholesterol-storage phenotype from a subpopulation of late endosomes/lysosomes (LE/LYSs). This was paralleled by repositioning and active transport of NPC2-containing vesicles to the cell surface. The potential of SpatTrack for other applications in intracellular transport studies will be discussed.

  19. The Bipartite Rac1 Guanine Nucleotide Exchange Factor Engulfment and Cell Motility 1/Dedicator of Cytokinesis 180 (Elmo1/Dock180) Protects Endothelial Cells from Apoptosis in Blood Vessel Development

    NARCIS (Netherlands)

    Schaeker, Kathrin; Bartsch, Susanne; Patry, Christian; Stoll, Sandra J.; Hillebrands, Jan-Luuk; Wieland, Thomas; Kroll, Jens

    2015-01-01

    Engulfment and cell motility 1/dedicator of cytokinesis 180 (Elmol/Dock180) is a bipartite guanine nucleotide exchange factor for the monomeric GTPase Ras-related C3 botulinum toxin substrate 1 (Racl). Elmol/Dock180 regulates Racl activity in a specific spatiotemporal manner in endothelial cells (EC

  20. Sickle cell disease: time for a targeted neonatal screening programme.

    LENUS (Irish Health Repository)

    Gibbons, C

    2015-02-01

    Ireland has seen a steady increase in paediatric sickle cell disease (SCD). In 2005, only 25% of children with SCD were referred to the haemoglobinopathy service in their first year. A non-funded screening programme was implemented. This review aimed to assess the impact screening has had. All children referred to the haemoglobinopathy service born in Ireland after 2005 were identified. Data was collected from the medical chart and laboratory system. Information was analysed using Microsoft Excel. 77 children with SCD were identified. The median age at antibiotic commencement in the screened group was 56 days compared with 447 days in the unscreened group, p = < 0.0003. 22 (28%) of infants were born in centre\\'s that do not screen and 17 (81%) were over 6 months old at referral, compared with 14 (21%) in the screened group. 6 (27%) of those in the unscreened group presented in acute crisis compared with 2 (3%) in the screened population. The point prevalence of SCD in Ireland is 0.2% in children under 15 yr of African and Asian descent. We identified delays in referral and treatment, which reflect the lack of government funded support and policy. We suggest all maternity units commence screening for newborns at risk of SCD. It is a cost effective intervention with a number needed to screen of just 4 to prevent a potentially fatal crisis.

  1. How substrate rigidity regulates the cellular motility

    Science.gov (United States)

    Sarvestani, Alireza

    2011-03-01

    Mechanical stiffness of bio-adhesive substrates has been recognized as a major regulator of cell motility. We present a simple physical model to study the crawling locomotion of a contractile cell on a soft elastic substrate. The mechanism of rigidity sensing is accounted for using Schwarz's two spring model (Schwarz et al. (2006) BioSystems 83, 225-232). The predicted dependency between the speed of motility and substrate stiffness is qualitatively consistent with experimental observations. The model demonstrates that the rigidity dependent motility of cells is rooted in the regulation of actomyosin contractile forces by substrate deformation at each anchorage point. On stiffer substrates, the traction forces required for cell translocation acquire larger magnitude but show weaker asymmetry which leads to slower cell motility. On very soft substrates, the model predicts a biphasic relationship between the substrate rigidity and the speed of locomotion, over a narrow stiffness range, which has been observed experimentally for some cell types.

  2. Crawling and turning in a minimal reaction-diffusion cell motility model: coupling cell shape and biochemistry

    CERN Document Server

    Camley, Brian A; Li, Bo; Levine, Herbert; Rappel, Wouter-Jan

    2016-01-01

    We study a minimal model of a crawling eukaryotic cell with a chemical polarity controlled by a reaction-diffusion mechanism describing Rho GTPase dynamics. The size, shape, and speed of the cell emerge from the combination of the chemical polarity, which controls the locations where actin polymerization occurs, and the physical properties of the cell, including its membrane tension. We find in our model both highly persistent trajectories, in which the cell crawls in a straight line, and turning trajectories, where the cell transitions from crawling in a line to crawling in a circle. We discuss the controlling variables for this turning instability, and argue that turning arises from a coupling between the reaction-diffusion mechanism and the shape of the cell. This emphasizes the surprising features that can arise from simple links between cell mechanics and biochemistry. Our results suggest that similar instabilities may be present in a broad class of biochemical descriptions of cell polarity.

  3. Microwell-Based Live Cell Imaging of NK Cell Dynamics to Assess Heterogeneity in Motility and Cytotoxic Response.

    Science.gov (United States)

    Vanherberghen, Bruno; Frisk, Thomas; Forslund, Elin; Olofsson, Per E; Guldevall, Karolin; Önfelt, Björn

    2016-01-01

    NK cell heterogeneity has primarily been studied either on the population level, measuring average responses, or on the single cell level by flow cytometry, providing static snapshots. These approaches have certain drawbacks, not enabling dynamic observations of single cells over extended periods of time. One of the primary limitations of single cell imaging has been throughput; it has been challenging to collect data for many cells due to their dynamic nature and migrating out of the field of view. Spatially confining cells combined with automated fluorescence microscopy enables the simultaneous monitoring of many NK cells in parallel for extended periods of time (>12 h). Such an approach allows us to dissect how the sum of individual NK cell responses translates to the global average response typically observed. PMID:27177659

  4. Myeloperoxidase Oxidized LDL Interferes with Endothelial Cell Motility through miR-22 and Heme Oxygenase 1 Induction: Possible Involvement in Reendothelialization of Vascular Injuries

    Directory of Open Access Journals (Sweden)

    Jalil Daher

    2014-01-01

    Full Text Available Cardiovascular disease linked to atherosclerosis is the leading cause of death worldwide. Atherosclerosis is mainly linked to dysfunction in vascular endothelial cells and subendothelial accumulation of oxidized forms of LDL. In the present study, we investigated the role of myeloperoxidase oxidized LDL (Mox-LDL in endothelial cell dysfunction. We studied the effect of proinflammatory Mox-LDL treatment on endothelial cell motility, a parameter essential for normal vascular processes such as angiogenesis and blood vessel repair. This is particularly important in the context of an atheroma plaque, where vascular wall integrity is affected and interference with its repair could contribute to progression of the disease. We investigated in vitro the effect of Mox-LDL on endothelial cells angiogenic properties and we also studied the signalling pathways that could be affected by analysing Mox-LDL effect on the expression of angiogenesis-related genes. We report that Mox-LDL inhibits endothelial cell motility and tubulogenesis through an increase in miR-22 and heme oxygenase 1 expression. Our in vitro data indicate that Mox-LDL interferes with parameters associated with angiogenesis. They suggest that high LDL levels in patients would impair their endothelial cell capacity to cope with a damaged endothelium contributing negatively to the progression of the atheroma plaque.

  5. Rab5 isoforms orchestrate a "division of labor" in the endocytic network; Rab5C modulates Rac-mediated cell motility.

    Directory of Open Access Journals (Sweden)

    Pin-I Chen

    Full Text Available Rab5, the prototypical Rab GTPase and master regulator of the endocytic pathway, is encoded as three differentially expressed isoforms, Rab5A, Rab5B and Rab5C. Here, we examined the differential effects of Rab5 isoform silencing on cell motility and report that Rab5C, but neither Rab5A nor Rab5B, is selectively associated with the growth factor-activation of Rac1 and with enhanced cell motility. Initial observations revealed that silencing of Rab5C expression, but neither Rab5A nor Rab5C, led to spindle-shaped cells that displayed reduced formation of membrane ruffles. When subjected to a scratch wound assay, cells depleted of Rab5C, but not Rab5A or Rab5B, demonstrated reduced cell migration. U937 cells depleted of Rab5C also displayed reduced cell motility in a Transwell plate migration assay. To examine activation of Rac, HeLa cells stably expressing GFP-Rac1 were independently depleted of Rab5A, Rab5B or Rab5C and seeded onto coverslips imprinted with a crossbow pattern. 3-D GFP-Rac1 images of micro-patterned cells show that GFP-Rac1 was less localized to the cell periphery in the absence of Rab5C. To confirm the connection between Rab5C and Rac activation, HeLa cells depleted of Rab5 isoforms were starved and then stimulated with EGF. Rac1 pull-down assays revealed that EGF-stimulated Rac1 activity was significantly suppressed in Rab5C-suppressed cells. To determine whether events upstream of Rac activation were affected by Rab5C, we observed that EGF-stimulated Akt phosphorylation was suppressed in cells depleted of Rab5C. Finally, since spatio-temporal assembly/disassembly of adhesion complexes are essential components of cell migration, we examined the effect of Rab5 isoform depletion on the formation of focal adhesion complexes. Rab5C-depleted HeLa cells have significantly fewer focal adhesion foci, in accordance with the lack of persistent lamellipodial protrusions and reduced directional migration. We conclude that Rab5 isoforms

  6. Screening of nanoparticle embryotoxicity using embryonic stem cells.

    Science.gov (United States)

    Campagnolo, Luisa; Fenoglio, Ivana; Massimiani, Micol; Magrini, Andrea; Pietroiusti, Antonio

    2013-01-01

    Due to the increasing use of engineered nanoparticles in many consumer products, rapid and economic tests for evaluating possible adverse effects on human health are urgently needed. In the present chapter the use of mouse embryonic stem cells as a valuable tool to in vitro screen nanoparticle toxicity on embryonic tissues is described. This in vitro method is a modification of the embryonic stem cell test, which has been widely used to screen soluble chemical compounds for their embryotoxic potential. The test offers an alternative to animal experimentation, reducing experimental costs and ethical issues. PMID:23592031

  7. Screening of nanoparticle embryotoxicity using embryonic stem cells.

    Science.gov (United States)

    Campagnolo, Luisa; Fenoglio, Ivana; Massimiani, Micol; Magrini, Andrea; Pietroiusti, Antonio

    2013-01-01

    Due to the increasing use of engineered nanoparticles in many consumer products, rapid and economic tests for evaluating possible adverse effects on human health are urgently needed. In the present chapter the use of mouse embryonic stem cells as a valuable tool to in vitro screen nanoparticle toxicity on embryonic tissues is described. This in vitro method is a modification of the embryonic stem cell test, which has been widely used to screen soluble chemical compounds for their embryotoxic potential. The test offers an alternative to animal experimentation, reducing experimental costs and ethical issues.

  8. Effect of the ulcerogenic agents ethanol, acetylsalicylic acid and taurocholate on actin cytoskeleton and cell motility in cultured rat gastric mucosal cells

    Institute of Scientific and Technical Information of China (English)

    Siamak Bidel; Harri Mustonen; Giti Khalighi-Sikaroudi; Eero Lehtonen; Pauli Puolakkainen; Tuula Kiviluoto; Eero Kivilaakso

    2005-01-01

    AIM: To assess the effects of ulcerogenic agents on actin cytoskeleton and cell motility and the contribution of oxidative stress.METHODS: Rat gastric mucosal cell monolayers were cultured on coverslips. The cells were exposed, with or without allopurinol (2 mmol/L), for 15 min to ethanol (10-150 mL/L), ASA (1-20 mmol/L) or taurocholate (1-20 mmol/L), then the cells were processed for actin and vinculin staining. Cell migration after wounding was also measured.RESULTS: Exposure to 10 mL/L ethanol caused divergence of zonula adherens-associated actin bundles of adjacent cells and decreased rate of migration. These actions were opposed by xanthine oxidase inhibitor allopurinol. Exposure to 50 mL/L ethanol induced degradation and divergence of zonula adherens-associated vinculin from adjacent cells,which was, again, partially reverted by allopurinol. With 1 mmol/L ASA actin filaments became shorter and thicker.However, higher concentrations (10, 20 mmol/L) of ASA returned microfilaments thinner and longer, and decreased rate of migration. Zonula adherens-associated actin bundles were moderately distorted with 10 mmol/L ASA and with 10 mmol/L taurocholate. Exposure to taurocholate provoked changes resembling those of ASA. Taurocholate 5-20 mmol/L decreased the rate of migration dose dependently. The effects of ASA and taurocholate were not prevented by allopurinol.CONCLUSION: All ulcerogenic agents decreased the rate of migration dose dependently and induced divergence of zonula adherens-associated actin bundles of adjacent cells.In addition, ethanol and ASA caused degradation of actin cytoskeleton. Oxidative stress seems to underlie ethanol,but not ASA or taurocholate, induced cytoskeletal damage.

  9. Delta opioid receptor on equine sperm cells: subcellular localization and involvement in sperm motility analyzed by computer assisted sperm analyzer (CASA

    Directory of Open Access Journals (Sweden)

    Lacalandra Giovanni M

    2010-06-01

    Full Text Available Abstract Background Opioid receptors and endogenous opioid peptides act not only in the control of nociceptive pathways, indeed several reports demonstrate the effects of opiates on sperm cell motility and morphology suggesting the importance of these receptors in the modulation of reproduction in mammals. In this study we investigated the expression of delta opioid receptors on equine spermatozoa by western blot/indirect immunofluorescence and its relationship with sperm cell physiology. Methods We analyzed viability, motility, capacitation, acrosome reaction and mitochondrial activity in the presence of naltrindole and DPDPE by means of a computer assisted sperm analyzer and a fluorescent confocal microscope. The evaluation of viability, capacitation and acrosome reaction was carried out by the double CTC/Hoechst staining, whereas mitochondrial activity was assessed by means of MitoTracker Orange dye. Results We showed that in equine sperm cells, delta opioid receptor is expressed as a doublet of 65 and 50 kDa molecular mass and is localized in the mid piece of tail; we also demonstrated that naltrindole, a delta opioid receptor antagonist, could be utilized in modulating several physiological parameters of the equine spermatozoon in a dose-dependent way. We also found that low concentrations of the antagonist increase sperm motility whereas high concentrations show the opposite effect. Moreover low concentrations hamper capacitation, acrosome reaction and viability even if the percentage of cells with active mitochondria seems to be increased; the opposite effect is exerted at high concentrations. We have also observed that the delta opioid receptor agonist DPDPE is scarcely involved in affecting the same parameters at the employed concentrations. Conclusions The results described in this paper add new important details in the comprehension of the mammalian sperm physiology and suggest new insights for improving reproduction and for

  10. Inhibition of Hypoxia-Induced Cell Motility by p16 in MDA-MB-231 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Liyuan Li, Yi Lu

    2010-01-01

    Full Text Available Our previous studies indicated that p16 suppresses breast cancer angiogenesis and metastasis, and downregulates VEGF gene expression by neutralizing the transactivation of the VEGF transcriptional factor HIF-1α. Hypoxia stimulates tumor malignant progression and induces HIF-1α. Because p16 neutralizes effect of HIF-1α and attenuates tumor metastatic progression, we intended to investigate whether p16 directly affects one or more aspects of the malignant process such as adhesion and migration of breast cancer cells. To approach this aim, MDA-MB-231 and other breast cancer cells stably transfected with Tet-on inducible p16 were used to study the p16 effect on growth, adhesion and migration of the cancer cells. We found that p16 inhibits breast cancer cell proliferation and migration, but has no apparent effect on cell adhesion. Importantly, p16 inhibits hypoxia-induced cell migration in breast cancer in parallel with its inhibition of HIF-1α transactivation activity. This study suggests that p16's ability to suppress tumor metastasis may be partially resulted from p16's inhibition on cell migration, in addition to its known functions on inhibition of cell proliferation, angiogenesis and induction of apoptosis.

  11. Heparan sulfate proteoglycans mediate interstitial flow mechanotransduction regulating MMP-13 expression and cell motility via FAK-ERK in 3D collagen.

    Directory of Open Access Journals (Sweden)

    Zhong-Dong Shi

    Full Text Available BACKGROUND: Interstitial flow directly affects cells that reside in tissues and regulates tissue physiology and pathology by modulating important cellular processes including proliferation, differentiation, and migration. However, the structures that cells utilize to sense interstitial flow in a 3-dimensional (3D environment have not yet been elucidated. Previously, we have shown that interstitial flow upregulates matrix metalloproteinase (MMP expression in rat vascular smooth muscle cells (SMCs and fibroblasts/myofibroblasts via activation of an ERK1/2-c-Jun pathway, which in turn promotes cell migration in collagen. Herein, we focused on uncovering the flow-induced mechanotransduction mechanism in 3D. METHODOLOGY/PRINCIPAL FINDINGS: Cleavage of rat vascular SMC surface glycocalyx heparan sulfate (HS chains from proteoglycan (PG core proteins by heparinase or disruption of HS biosynthesis by silencing N-deacetylase/N-sulfotransferase 1 (NDST1 suppressed interstitial flow-induced ERK1/2 activation, interstitial collagenase (MMP-13 expression, and SMC motility in 3D collagen. Inhibition or knockdown of focal adhesion kinase (FAK also attenuated or blocked flow-induced ERK1/2 activation, MMP-13 expression, and cell motility. Interstitial flow induced FAK phosphorylation at Tyr925, and this activation was blocked when heparan sulfate proteoglycans (HSPGs were disrupted. These data suggest that HSPGs mediate interstitial flow-induced mechanotransduction through FAK-ERK. In addition, we show that integrins are crucial for mechanotransduction through HSPGs as they mediate cell spreading and maintain cytoskeletal rigidity. CONCLUSIONS/SIGNIFICANCE: We propose a conceptual mechanotransduction model wherein cell surface glycocalyx HSPGs, in the presence of integrin-mediated cell-matrix adhesions and cytoskeleton organization, sense interstitial flow and activate the FAK-ERK signaling axis, leading to upregulation of MMP expression and cell motility in 3D

  12. Down-regulation of Sonic hedgehog signaling pathway activity is involved in 5-fluorouracil-induced apoptosis and motility inhibition in Hep3B cells

    Institute of Scientific and Technical Information of China (English)

    Qiyu Wang; Shuhong Huang; Ling Yang; Ling Zhao; Yuxia Yin; Zhongzhen Liu; Zheyu Chen; Hongwei Zhang

    2008-01-01

    The Sonic hedgehog (SHh) pathway plays a critical role in normal embryogenesis and carcinogenesis, but its function in cancer cells treated with 5-fluorouracil (5-FU) remains unknown. We examined the expression of a subset of SHh signaling pathway genes, including SHh, SMO, PTC1, Su(Fu) and HIP in human hepatocellular carcinoma (HCC) cell lines,Hep3B and HepG2, treated with 5-FU by reverse transcriptionpolymerase chain reaction. Using trypan blue analysis,3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling assay, we also detected the apoptosis of Hep3B cells resulting from the transfection of pCS2-Gli1 expression vector combined with 5-FU treatment.The motility of the cells was detected by scratch wound closure assay. The expression and subcellular location of PTC1 protein in Hep3B cells treated by 5-FU were also investigated by Western blot analysis and immunofluorescent microscopy. The results indicated that the expression of SHh pathway target molecules at both messenger RNA and protein levels are evidently down-regulated in Hep3B cells treated with 5-FU. The overexpression of Gli1 restores cell viability and, to some extent, the migration abilities inhibited by 5-FU.Furthermore, 5-FU treatment affects the subcellular localization of PTC1 protein, a key member in SHh signaling pathway. Our data showed that the down-regulation of SHh signaling pathway activity was involved in 5-FU-induced apoptosis and the inhibition of motility in hedgehog-activated HCC cell lines. This implies that the combination of SHh signaling pathway inhibitor and 5-FU-based chemotherapy might represent a more promising strategy against HCC.

  13. Expression of E1AF/PEA3, an Ets-related transcription factor in human non-small-cell lung cancers: its relevance in cell motility and invasion.

    Science.gov (United States)

    Hiroumi, H; Dosaka-Akita, H; Yoshida, K; Shindoh, M; Ohbuchi, T; Fujinaga, K; Nishimura, M

    2001-09-01

    Cell invasion and metastasis characterize the malignant potential of non-small-cell lung cancers (NSCLCs). We have previously reported that E1AF, a member of the Ets-related transcription factor family, confers invasive phenotype on breast cancer and oral squamous-cell carcinoma cell lines. In our study, we analyzed the E1AF expression in cell lines and resected tumors of NSCLCs by Northern blot and in situ hybridization analyses and found that 15 of 17 cell lines and 12 of 19 tumors expressed E1AF mRNA while normal lung tissue and concomitant normal cells within tumors did not. To examine the biologic importance of E1AF in NSCLCs, we introduced the E1AF gene into VMRC-LCD and NCI-H226, NSCLC cell lines lacking E1AF expression, and examined cell motility and invasion activities. E1AF-transfected VMRC-LCD cells showed increased cell motility that was 2-fold that of parental and vector-transfected control cells (p H226 (p H226 cells but not in their parental or vector-transfected control cells. Ets-1 mRNA expression was found in E1AF-transfected VMRC-LCD cells but not in parental or vector-transfected cells. HGF further induced expression of the Ets-1 and urokinase-type plasminogen activator (uPA) genes specifically in E1AF-transfected cells. These findings suggest that E1AF plays a substantial role in the cell motility and invasion of NSCLCs. PMID:11519038

  14. Recovery of indium from LCD screens of discarded cell phones.

    Science.gov (United States)

    Silveira, A V M; Fuchs, M S; Pinheiro, D K; Tanabe, E H; Bertuol, D A

    2015-11-01

    Advances in technological development have resulted in high consumption of electrical and electronic equipment (EEE), amongst which are cell phones, which have LCD (liquid crystal display) screens as one of their main components. These multilayer screens are composed of different materials, some with high added value, as in the case of the indium present in the form of indium tin oxide (ITO, or tin-doped indium oxide). Indium is a precious metal with relatively limited natural reserves (Dodbida et al., 2012), so it can be profitable to recover it from discarded LCD screens. The objective of this study was to develop a complete process for recovering indium from LCD screens. Firstly, the screens were manually removed from cell phones. In the next step, a pretreatment was developed for removal of the polarizing film from the glass of the LCD panels, because the adherence of this film to the glass complicated the comminution process. The choice of mill was based on tests using different equipment (knife mill, hammer mill, and ball mill) to disintegrate the LCD screens, either before or after removal of the polarizing film. In the leaching process, it was possible to extract 96.4 wt.% of the indium under the following conditions: 1.0M H2SO4, 1:50 solid/liquid ratio, 90°C, 1h, and stirring at 500 rpm. The results showed that the best experimental conditions enabled extraction of 613 mg of indium/kg of LCD powder. Finally, precipitation of the indium with NH4OH was tested at different pH values, and 99.8 wt.% precipitation was achieved at pH 7.4.

  15. Murine epidermal growth factor (EGF) fragment (33-42) inhibits both EGF- and laminin-dependent endothelial cell motility and angiogenesis.

    Science.gov (United States)

    Nelson, J; Allen, W E; Scott, W N; Bailie, J R; Walker, B; McFerran, N V; Wilson, D J

    1995-09-01

    Laminin, murine epidermal growth factor (mEGF), and the synthetic laminin peptide Lam.B1(925-933) (a linear peptide from the B1 chain of murine laminin, CDPGY1GSR-amide) all stimulate endothelial cell motility above basal rates, whereas a synthetic mEGF fragment, mEGF33-42 (a linear peptide from the C-loop of mEGF, acetyl-C-[S-Acm]-VIGYSGDR-C-[S-Acm]-amide), inhibits motility. In both human SK HEP-1 and embryonic chick endothelial cells, mEGF33-42 blocks both EGF- and laminin-stimulated locomotion of endothelial cells. In vivo, mEGF33-42 also blocks both laminin- and mEGF-induced angiogenesis in the chick. In the human cell line. Lam.B1(925-933) has an additive effect in coincubation with either laminin or mEGF, but it blocks their effects in the chick cells. Lam.B1(925-933) alone stimulates angiogenesis in the chick but blocks laminin-induced angiogenesis. Thus, mEGF33-42 acts as a general laminin antagonist, whereas Lam.B1(925-933) acts as a laminin agonist in human cells, but in chick cells it acts as a partial antagonist. We propose that the presence of an anionic group at the eighth residue of mEGF33-42 may be the source of the antagonistic effects seen with this peptide as compared with the laminin fragment. These findings have important implications in the design of human antiangiogenic agents, and also in the use of chick models in the study of human disease. PMID:7543818

  16. Cell-based screens and phenomics with fission yeast.

    Science.gov (United States)

    Rallis, Charalampos; Bähler, Jürg

    2016-01-01

    Next-generation sequencing approaches have considerably advanced our understanding of genome function and regulation. However, the knowledge of gene function and complex cellular processes remains a challenge and bottleneck in biological research. Phenomics is a rapidly emerging area, which seeks to rigorously characterize all phenotypes associated with genes or gene variants. Such high-throughput phenotyping under different conditions can be a potent approach toward gene function. The fission yeast Schizosaccharomyces pombe (S. pombe) is a proven eukaryotic model organism that is increasingly used for genomewide screens and phenomic assays. In this review, we highlight current large-scale, cell-based approaches used with S. pombe, including computational colony-growth measurements, genetic interaction screens, parallel profiling using barcodes, microscopy-based cell profiling, metabolomic methods and transposon mutagenesis. These diverse methods are starting to offer rich insights into the relationship between genotypes and phenotypes. PMID:26523839

  17. Differential expression of autocrine motility factor receptor (AMFR) mRNA in normal and cancer cells detected by in situ hybridization

    Institute of Scientific and Technical Information of China (English)

    HUANGBAIQU; AVRAHAMRAZ

    1995-01-01

    The receptor for autocrine motility factor(AMFR) is known to be involved in the process of MF-mediated cell migration and metastasis.This paper describes the procedures of non-radioactive in situ hybridization(ISH) detection of AMFR mRNA in both paraffin-embedded surgical sections and cultured cells using either biotinylated oligonucleotide probes of digoxigenin-labeled RNA probes.The results showed that the AMFR mRNA was expressed at an enhanced level in hyperplastic and malignant tissues of breast and prostate cancer patient surgical specimens,indicating that the elevated AMFR expression was associated with the tissue malignancy.Moreover,AMFR mRNA was detected in both normal and carcinoma cells when cultured at a subconfluent density.However,AMFR expression was inhibited in confluent normal(3T3-A31 murine fibroblast and FHs 738 BL huamn bladder)cells while it continued to express in carcinoma(J82 human bladder) and metastatic(3T3-M murine fibroblast) cells irrespective of cell density.This suggested a cell-cell contact down-regulation of AMFR mRNA expression in normal but not in cancer cells.The ISH data obtained in this study are closely consistent with the AMFR protein expression pattern previously reported,implying that the differential expression of AMFR gene may be rgeualted and controlled at the transcriptional level.

  18. Secondary solid cancer screening following hematopoietic cell transplantation

    Science.gov (United States)

    Inamoto, Y; Shah, NN; Savani, BN; Shaw, BE; Abraham, AA; Ahmed, IA; Akpek, G; Atsuta, Y; Baker, KS; Basak, GW; Bitan, M; DeFilipp, Z; Gregory, TK; Greinix, HT; Hamadani, M; Hamilton, BK; Hayashi, RJ; Jacobsohn, DA; Kamble, RT; Kasow, KA; Khera, N; Lazarus, HM; Malone, AK; Lupo-Stanghellini, MT; Margossian, SP; Muffly, LS; Norkin, M; Ramanathan, M; Salooja, N; Schoemans, H; Wingard, JR; Wirk, B; Wood, WA; Yong, A; Duncan, CN; Flowers, MED; Majhail, NS

    2016-01-01

    Hematopoietic stem cell transplant (HCT) recipients have a substantial risk of developing secondary solid cancers, particularly beyond 5 years after HCT and without reaching a plateau overtime. A working group was established through the Center for International Blood and Marrow Transplant Research and the European Group for Blood and Marrow Transplantation with the goal to facilitate implementation of cancer screening appropriate to HCT recipients. The working group reviewed guidelines and methods for cancer screening applicable to the general population and reviewed the incidence and risk factors for secondary cancers after HCT. A consensus approach was used to establish recommendations for individual secondary cancers. The most common sites include oral cavity, skin, breast and thyroid. Risks of cancers are increased after HCT compared with the general population in skin, thyroid, oral cavity, esophagus, liver, nervous system, bone and connective tissues. Myeloablative TBI, young age at HCT, chronic GVHD and prolonged immunosuppressive treatment beyond 24 months were well-documented risk factors for many types of secondary cancers. All HCT recipients should be advised of the risks of secondary cancers annually and encouraged to undergo recommended screening based on their predisposition. Here we propose guidelines to help clinicians in providing screening and preventive care for secondary cancers among HCT recipients. PMID:25822223

  19. Secondary solid cancer screening following hematopoietic cell transplantation.

    Science.gov (United States)

    Inamoto, Y; Shah, N N; Savani, B N; Shaw, B E; Abraham, A A; Ahmed, I A; Akpek, G; Atsuta, Y; Baker, K S; Basak, G W; Bitan, M; DeFilipp, Z; Gregory, T K; Greinix, H T; Hamadani, M; Hamilton, B K; Hayashi, R J; Jacobsohn, D A; Kamble, R T; Kasow, K A; Khera, N; Lazarus, H M; Malone, A K; Lupo-Stanghellini, M T; Margossian, S P; Muffly, L S; Norkin, M; Ramanathan, M; Salooja, N; Schoemans, H; Wingard, J R; Wirk, B; Wood, W A; Yong, A; Duncan, C N; Flowers, M E D; Majhail, N S

    2015-08-01

    Hematopoietic stem cell transplant (HCT) recipients have a substantial risk of developing secondary solid cancers, particularly beyond 5 years after HCT and without reaching a plateau overtime. A working group was established through the Center for International Blood and Marrow Transplant Research and the European Group for Blood and Marrow Transplantation with the goal to facilitate implementation of cancer screening appropriate to HCT recipients. The working group reviewed guidelines and methods for cancer screening applicable to the general population and reviewed the incidence and risk factors for secondary cancers after HCT. A consensus approach was used to establish recommendations for individual secondary cancers. The most common sites include oral cavity, skin, breast and thyroid. Risks of cancers are increased after HCT compared with the general population in skin, thyroid, oral cavity, esophagus, liver, nervous system, bone and connective tissues. Myeloablative TBI, young age at HCT, chronic GVHD and prolonged immunosuppressive treatment beyond 24 months were well-documented risk factors for many types of secondary cancers. All HCT recipients should be advised of the risks of secondary cancers annually and encouraged to undergo recommended screening based on their predisposition. Here we propose guidelines to help clinicians in providing screening and preventive care for secondary cancers among HCT recipients.

  20. Cyclin-Dependent Kinase 5 (CDK5 Controls Melanoma Cell Motility, Invasiveness, and Metastatic Spread—Identification of a Promising Novel therapeutic target

    Directory of Open Access Journals (Sweden)

    Savita Bisht

    2015-08-01

    Full Text Available Despite considerable progress in recent years, the overall prognosis of metastatic malignant melanoma remains poor, and curative therapeutic options are lacking. Therefore, better understanding of molecular mechanisms underlying melanoma progression and metastasis, as well as identification of novel therapeutic targets that allow inhibition of metastatic spread, are urgently required. The current study provides evidence for aberrant cyclin-dependent kinase 5 (CDK5 activation in primary and metastatic melanoma lesions by overexpression of its activator protein CDK5R1/p35. Moreover, using melanoma in vitro model systems, shRNA-mediated inducible knockdown of CDK5 was found to cause marked inhibition of cell motility, invasiveness, and anchorage-independent growth, while at the same time net cell growth was not affected. In vivo, CDK5 knockdown inhibited growth of orthotopic xenografts as well as formation of lung and liver colonies in xenogenic injection models mimicking systemic metastases. Inhibition of lung metastasis was further validated in a syngenic murine melanoma model. CDK5 knockdown was accompanied by dephosphorylation and overexpression of caldesmon, and concomitant caldesmon knockdown rescued cell motility and proinvasive phenotype. Finally, it was found that pharmacological inhibition of CDK5 activity by means of roscovitine as well as by a novel small molecule CDK5-inhibitor, N-(5-isopropylthiazol-2-yl-3-phenylpropanamide, similarly caused marked inhibition of invasion/migration, colony formation, and anchorage-independent growth of melanoma cells. Thus, experimental data presented here provide strong evidence for a crucial role of aberrantly activated CDK5 in melanoma progression and metastasis and establish CDK5 as promising target for therapeutic intervention.

  1. BCR and its mutants, the reciprocal t(9;22-associated ABL/BCR fusion proteins, differentially regulate the cytoskeleton and cell motility

    Directory of Open Access Journals (Sweden)

    Puccetti Elena

    2006-11-01

    Full Text Available Abstract Background The reciprocal (9;22 translocation fuses the bcr (breakpoint cluster region gene on chromosome 22 to the abl (Abelson-leukemia-virus gene on chromosome 9. Depending on the breakpoint on chromosome 22 (the Philadelphia chromosome – Ph+ the derivative 9+ encodes either the p40(ABL/BCR fusion transcript, detectable in about 65% patients suffering from chronic myeloid leukemia, or the p96(ABL/BCR fusion transcript, detectable in 100% of Ph+ acute lymphatic leukemia patients. The ABL/BCRs are N-terminally truncated BCR mutants. The fact that BCR contains Rho-GEF and Rac-GAP functions strongly suggest an important role in cytoskeleton modeling by regulating the activity of Rho-like GTPases, such as Rho, Rac and cdc42. We, therefore, compared the function of the ABL/BCR proteins with that of wild-type BCR. Methods We investigated the effects of BCR and ABL/BCRs i. on the activation status of Rho, Rac and cdc42 in GTPase-activation assays; ii. on the actin cytoskeleton by direct immunofluorescence; and iii on cell motility by studying migration into a three-dimensional stroma spheroid model, adhesion on an endothelial cell layer under shear stress in a flow chamber model, and chemotaxis and endothelial transmigration in a transwell model with an SDF-1α gradient. Results Here we show that both ABL/BCRs lost fundamental functional features of BCR regarding the regulation of small Rho-like GTPases with negative consequences on cell motility, in particular on the capacity to adhere to endothelial cells. Conclusion Our data presented here describe for the first time an analysis of the biological function of the reciprocal t(9;22 ABL/BCR fusion proteins in comparison to their physiological counterpart BCR.

  2. Prevalence of sickle cell disease and sickle cell trait in national neonatal screening studies

    OpenAIRE

    Luciana Garcia Lervolino; Paulo Eduardo Almeida Baldin; Silvia Miguéis Picado; Karina Barreto Calil; Ana Amélia Viel; Luiz Alexandre Freixo Campos

    2011-01-01

    Sickle cell anemia is the best known hereditary blood disorder; there are serious complications associated with the condition. Diagnosis and early intervention reduce morbidity and mortality. These benefits have resulted in the widespread use of newborn screening education programs. In Brazil, the National Neonatal Screening Program established by decree 822/01 included sickle cell disease in the list of diseases tested in the so called "heel prick test". Since then, national studies of the r...

  3. Microchip Screening Platform for Single Cell Assessment of NK Cell Cytotoxicity

    Science.gov (United States)

    Guldevall, Karolin; Brandt, Ludwig; Forslund, Elin; Olofsson, Karl; Frisk, Thomas W.; Olofsson, Per E.; Gustafsson, Karin; Manneberg, Otto; Vanherberghen, Bruno; Brismar, Hjalmar; Kärre, Klas; Uhlin, Michael; Önfelt, Björn

    2016-01-01

    Here, we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK) cells within larger populations. Human primary NK cells were distributed across a silicon–glass microchip containing 32,400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis, the numbers of NK and live or dead target cells in each well could be assessed at different time points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75%) were non-cytotoxic against the leukemia cell line K562, some NK cells were able to kill several (≥3) target cells within the 12-h long experiment. In addition, the screening approach was adapted to increase the chance to find and evaluate serial killing NK cells. Even if the cytotoxic potential varied between donors, it was evident that a small fraction of highly cytotoxic NK cells were responsible for a substantial portion of the killing. We demonstrate multiple assays where our platform can be used to enumerate and characterize cytotoxic cells, such as NK or T cells. This approach could find use in clinical applications, e.g., in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy. PMID:27092139

  4. Microchip screening platform for single cell assessment of NK cell cytotoxicity

    Directory of Open Access Journals (Sweden)

    Karolin eGuldevall

    2016-04-01

    Full Text Available Here we report a screening platform for assessment of the cytotoxic potential of individual natural killer (NK cells within larger populations. Human primary NK cells were distributed across a silicon-glass microchip containing 32 400 individual microwells loaded with target cells. Through fluorescence screening and automated image analysis the numbers of NK and live or dead target cells in each well could be assessed at different time points after initial mixing. Cytotoxicity was also studied by time-lapse live-cell imaging in microwells quantifying the killing potential of individual NK cells. Although most resting NK cells (≈75% were non-cytotoxic against the leukemia cell line K562, some NK cells were able to kill several (≥3 target cells within the 12 hours long experiment. In addition, the screening approach was adapted to increase the chance to find and evaluate serial killing NK cells. Even if the cytotoxic potential varied between donors it was evident that a small fraction of highly cytotoxic NK cells were responsible for a substantial portion of the killing. We demonstrate multiple assays where our platform can be used to enumerate and characterize cytotoxic cells, such as NK or T cells. This approach could find use in clinical applications, e.g. in the selection of donors for stem cell transplantation or generation of highly specific and cytotoxic cells for adoptive immunotherapy.

  5. One isoform of Arg/Abl2 tyrosine kinase is nuclear and the other seven cytosolic isoforms differently modulate cell morphology, motility and the cytoskeleton

    Energy Technology Data Exchange (ETDEWEB)

    Bianchi, Cristina; Torsello, Barbara; Di Stefano, Vitalba; Zipeto, Maria A.; Facchetti, Rita; Bombelli, Silvia; Perego, Roberto A., E-mail: roberto.perego@unimib.it

    2013-08-01

    The non-receptor tyrosine kinase Abelson related gene (Arg/Abl2) regulates cell migration and morphogenesis by modulating the cytoskeleton. Arg promotes actin-based cell protrusions and spreading, and inhibits cell migration by attenuating stress fiber formation and contractility via activation of the RhoA inhibitor, p190RhoGAP, and by regulating focal adhesion dynamics also via CrkII phosphorylation. Eight full-length Arg isoforms with different N- and C-termini are endogenously expressed in human cells. In this paper, the eight Arg isoforms, subcloned in the pFLAG-CMV2 vector, were transfected in COS-7 cells in order to study their subcellular distribution and role in cell morphology, migration and cytoskeletal modulation. The transfected 1BSCTS Arg isoform has a nuclear distribution and phosphorylates CrkII in the nucleus, whilst the other isoforms are detected in the cytoplasm. The 1BLCTL, 1BSCTL, 1ASCTS isoforms were able to significantly decrease stress fibers, induce cell shrinkage and filopodia-like protrusions with a significant increase in p190RhoGAP phosphorylation. In contrast, 1ALCTL, 1ALCTS, 1ASCTL and 1BLCTS isoforms do not significantly decrease stress fibers and induce the formation of retraction tail-like protrusions. The 1BLCTL and 1ALCTL isoforms have different effects on cell migration and focal adhesions. All these data may open new perspectives to study the mechanisms of cell invasiveness. -Highlights: • Each of the eight Arg isoforms was transfected in COS-7 cells. • Only the 1BSCTS Arg isoform has a nuclear distribution in transfected cells. • The cytoplasmic isoforms and F-actin colocalize cortically and in cell protrusions. • Arg isoforms differently phosphorylate p190RhoGAP and CrkII. • Arg isoforms differently modulate stress fibers, cell protrusions and motility.

  6. Red blood cell parameters in antenatal nonsickling hemoglobinopathy screening

    Directory of Open Access Journals (Sweden)

    Bencaiova G

    2015-04-01

    Full Text Available Gabriela Bencaiova, Kristina Dapoto, Roland Zimmermann, Alexander Krafft Department of Obstetrics and Gynecology, Institute of Obstetric Research, University Hospital Zurich, Zurich, Switzerland Objective: To find a hematological parameter and the cut-off level for identification of nonsickling hemoglobinopathies in pregnant women. Materials and methods: Venous blood samples of 849 women with singleton pregnancies were collected at the first visit. All women who met inclusion criteria were examined for nonsickling hemoglobinopathy. On the basis of the sensitivity and the specificity of different cut-off levels for hematological parameters, we calculated the optimal clinically practicable parameter for screening of nonsickling hemoglobinopathies in pregnant women. Results: On the basis of the sensitivity and the specificity, the best screening parameters for the identification of nonsickling hemoglobinopathies among nonanemic pregnant women are mean corpuscular volume (MCV with cut-off ≤80 fL (Youden’s index 91.2%, mean corpuscular hemoglobin (MCH <27.5 pg (Youden’s index 90.7%, and microcytosis (MRC ≥3% (Youden’s index 90.2%. An analysis using receiver operating characteristic curves and the calculated Youden’s index showed that MCV ≤76 fL, MCH ≤24 pg, or MRC ≥10% are the best red blood cell indices for the screening of nonsickling hemoglobinopathy among anemic women with iron deficiency. Conclusion: Our results suggest targeted screening for nonsickling hemoglobinopathies in nonanemic pregnant women with MCV ≤80 fL, MCH ≤27.5 pg, or MRC ≥3% and in anemic women with MCV ≤76 fL, MCH ≤24 pg, or MRC ≥10%. Keywords: anemia, antenatal, hemoglobinopathy, pregnancy, screening, hemoglobin, hematological parameters

  7. From invasion to latency: intracellular noise and cell motility as key controls of the competition between resource-limited cellular populations

    KAUST Repository

    Guerrero, Pilar

    2015-04-02

    © 2015, Springer-Verlag Berlin Heidelberg. In this paper we analyse stochastic models of the competition between two resource-limited cell populations which differ in their response to nutrient availability: the resident population exhibits a switch-like response behaviour while the invading population exhibits a bistable response. We investigate how noise in the intracellular regulatory pathways and cell motility influence the fate of the incumbent and invading populations. We focus initially on a spatially homogeneous system and study in detail the role of intracellular noise. We show that in such well-mixed systems, two distinct regimes exist: In the low (intracellular) noise limit, the invader has the ability to invade the resident population, whereas in the high noise regime competition between the two populations is found to be neutral and, in accordance with neutral evolution theory, invasion is a random event. Careful examination of the system dynamics leads us to conclude that (i) even if the invader is unable to invade, the distribution of survival times, PS(t), has a fat-tail behaviour (PS(t)∼t-1) which implies that small colonies of mutants can coexist with the resident population for arbitrarily long times, and (ii) the bistable structure of the invading population increases the stability of the latent population, thus increasing their long-term likelihood of survival, by decreasing the intensity of the noise at the population level. We also examine the effects of spatial inhomogeneity. In the low noise limit we find that cell motility is positively correlated with the aggressiveness of the invader as defined by the time the invader takes to invade the resident population: the faster the invasion, the more aggressive the invader.

  8. Pediatric intestinal motility disorders

    OpenAIRE

    Gfroerer, Stefan; Rolle, Udo

    2015-01-01

    Pediatric intestinal motility disorders affect many children and thus not only impose a significant impact on pediatric health care in general but also on the quality of life of the affected patient. Furthermore, some of these conditions might also have implications for adulthood. Pediatric intestinal motility disorders frequently present as chronic constipation in toddler age children. Most of these conditions are functional, meaning that constipation does not have an organic etiology, but i...

  9. Mammalian Sperm Motility: Observation and Theory

    KAUST Repository

    Gaffney, E.A.

    2011-01-21

    Mammalian spermatozoa motility is a subject of growing importance because of rising human infertility and the possibility of improving animal breeding. We highlight opportunities for fluid and continuum dynamics to provide novel insights concerning the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian sperm through the numerous environments of the female reproductive tract. This process demands certain specific changes to flagellar movement and motility for which further mechanical insight would be valuable, although this requires improved modeling capabilities, particularly to increase our understanding of sperm progression in vivo. We summarize current theoretical studies, highlighting the synergistic combination of imaging and theory in exploring sperm motility, and discuss the challenges for future observational and theoretical studies in understanding the underlying mechanics. © 2011 by Annual Reviews. All rights reserved.

  10. Mammalian Sperm Motility: Observation and Theory

    Science.gov (United States)

    Gaffney, E. A.; Gadêlha, H.; Smith, D. J.; Blake, J. R.; Kirkman-Brown, J. C.

    2011-01-01

    Mammalian spermatozoa motility is a subject of growing importance because of rising human infertility and the possibility of improving animal breeding. We highlight opportunities for fluid and continuum dynamics to provide novel insights concerning the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian sperm through the numerous environments of the female reproductive tract. This process demands certain specific changes to flagellar movement and motility for which further mechanical insight would be valuable, although this requires improved modeling capabilities, particularly to increase our understanding of sperm progression in vivo. We summarize current theoretical studies, highlighting the synergistic combination of imaging and theory in exploring sperm motility, and discuss the challenges for future observational and theoretical studies in understanding the underlying mechanics.

  11. BubR1 Acts as a Promoter in Cellular Motility of Human Oral Squamous Cancer Cells through Regulating MMP-2 and MMP-9

    Directory of Open Access Journals (Sweden)

    Chou-Kit Chou

    2015-07-01

    Full Text Available BubR1 is a critical component of spindle assembly checkpoint, ensuring proper chromatin segregation during mitosis. Recent studies showed that BubR1 was overexpressed in many cancer cells, including oral squamous cell carcinomas (OSCC. However, the effect of BubR1 on metastasis of OSCC remains unclear. This study aimed to unravel the role of BubR1 in the progression of OSCC and confirm the expression of BubR1 in a panel of malignant OSCC cell lines with different invasive abilities. The results of quantitative real-time PCR showed that the mRNA level of BubR1 was markedly increased in four OSCC cell lines, Ca9-22, HSC3, SCC9 and Cal-27 cells, compared to two normal cells, normal human oral keratinocytes (HOK and human gingival fibroblasts (HGF. Moreover, the expression of BubR1 in these four OSCC cell lines was positively correlated with their motility. Immunofluorescence revealed that BubR1 was mostly localized in the cytosol of human gingival carcinoma Ca9-22 cells. BubR1 knockdown significantly decreased cellular invasion but slightly affect cellular proliferation on both Ca9-22 and Cal-27 cells. Consistently, the activities of metastasis-associated metalloproteinases MMP-2 and MMP-9 were attenuated in BubR1 knockdown Ca9-22 cells, suggesting the role of BubR1 in promotion of OSCC migration. Our present study defines an alternative pathway in promoting metastasis of OSCC cells, and the expression of BubR1 could be a prognostic index in OSCC patients.

  12. Cyclin-dependent kinase 5 regulates the proliferation, motility and invasiveness of lung cancer cells through its effects on cytoskeletal remodeling.

    Science.gov (United States)

    Liu, Jun-Li; Gu, Run-Xia; Zhou, Xiao-Shu; Zhou, Fang-Zheng; Wu, Gang

    2015-09-01

    Determining the molecular phenotype is a key to understanding and predicting the metastatic potential and the prognosis for patients with lung cancer. Our previous study demonstrated that increased expression of cyclin‑dependent kinase 5 (CDK5) in patients with non‑small cell lung cancer (NSCLC) is associated with a poorer prognosis. The present study aimed to further investigate the underlying mechanism of CDK5 in vitro and in vivo using the A549 human NSCLC cell line. A 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assay was used to quantify the proliferation of the A549 cells; migration assay and invasiveness assays were performed using Transwell chambers and wound healing assays were used to assess cell motility, which was assessed by measuring the movement of cells. Inhibition of CDK5 by roscovitine and small interfering (si)RNA was used to investigate the mechanism of CDK5 in the process of A549 lung cancer cell proliferation, migration and invasion. The results demonstrated that functional inhibition of CDK5 using roscovitine and siRNA markedly suppressed the proliferation of A549 cells and resulted in a reduced tumor mass in vivo. In addition, the hinhibition of CDK5 reduced the migration and invasiveness of the A549 cells in vitro and in vivo. Notably, CDK5 inhibition also impaired tumor cell cytoskeletal remodeling and led to loss of cell polarity, which may partially explain the reduction of A549 cell mobility and invasiveness. The results of the present study revealed that CDK5 may be important in the regulation of migration and invasiveness in NSCLC through its effects on cytoskeletal remodeling. PMID:26018459

  13. Motility modes of the parasite Trypanosoma brucei

    Science.gov (United States)

    Temel, Fatma Zeynep; Qu, Zijie; McAllaster, Michael; de Graffenried, Christopher; Breuer, Kenneth

    2015-11-01

    The parasitic single-celled protozoan Trypanosoma brucei causes African Sleeping Sickness, which is a fatal disease in humans and animals that threatens more than 60 million people in 36 African countries. Cell motility plays a critical role in the developmental phases and dissemination of the parasite. Unlike many other motile cells such as bacteria Escherichia coli or Caulobacter crescentus, the flagellum of T. brucei is attached along the length of its awl-like body, producing a unique mode of motility that is not fully understood or characterized. Here, we report on the motility of T. brucei, which swims using its single flagellum employing both rotating and undulating propulsion modes. We tracked cells in real-time in three dimensions using fluorescent microscopy. Data obtained from experiments using both short-term tracking within the field of view and long-term tracking using a tracking microscope were analyzed. Motility modes and swimming speed were analyzed as functions of cell size, rotation rate and undulation pattern. Research supported by NSF.

  14. Heregulin/ErbB3 Signaling Enhances CXCR4-Driven Rac1 Activation and Breast Cancer Cell Motility via Hypoxia-Inducible Factor 1α.

    Science.gov (United States)

    Lopez-Haber, Cynthia; Barrio-Real, Laura; Casado-Medrano, Victoria; Kazanietz, Marcelo G

    2016-08-01

    The growth factor heregulin (HRG), a ligand of ErbB3 and ErbB4 receptors, contributes to breast cancer development and the promotion of metastatic disease, and its expression in breast tumors has been associated with poor clinical outcome and resistance to therapy. In this study, we found that breast cancer cells exposed to sustained HRG treatment show markedly enhanced Rac1 activation and migratory activity in response to the CXCR4 ligand SDF-1/CXCL12, effects mediated by P-Rex1, a Rac-guanine nucleotide exchange factor (GEF) aberrantly expressed in breast cancer. Notably, HRG treatment upregulates surface expression levels of CXCR4, a G protein-coupled receptor (GPCR) implicated in breast cancer metastasis and an indicator of poor prognosis in breast cancer patients. A detailed mechanistic analysis revealed that CXCR4 upregulation and sensitization of the Rac response/motility by HRG are mediated by the transcription factor hypoxia-inducible factor 1α (HIF-1α) via ErbB3 and independently of ErbB4. HRG caused prominent induction in the nuclear expression of HIF-1α, which transcriptionally activates the CXCR4 gene via binding to a responsive element located in positions -1376 to -1372 in the CXCR4 promoter, as revealed by mutagenesis analysis and chromatin immunoprecipitation (ChIP). Our results uncovered a novel function for ErbB3 in enhancing breast cancer cell motility and sensitization of the P-Rex1/Rac1 pathway through HIF-1α-mediated transcriptional induction of CXCR4. PMID:27185877

  15. Stem cells and small molecule screening: haploid embryonic stem cells as a new tool

    Institute of Scientific and Technical Information of China (English)

    Bi WU; Wei LI; Liu WANG; Zhong-hua LIU; Xiao-yang ZHAO

    2013-01-01

    Stem cells can both self-renew and differentiate into various cell types under certain conditions,which makes them a good model for development and disease studies.Recently,chemical approaches have been widely applied in stem cell biology by promoting stem cell self-renewal,proliferation,differentiation and somatic cell reprogramming using specific small molecules.Conversely,stem cells and their derivatives also provide an efficient and robust platform for small molecule and drug screening.Here,we review the current research and applications of small molecules that modulate stem cell self-renewal and differentiation and improve reprogramming,as well as the applications that use stem cells as a tool for small molecule screening.Moreover,we introduce the recent advance in haploid embryonic stem cells research.Haploid embryonic stem cells maintain haploidy and stable growth over extensive passages,possess the ability to differentiate into all three germ layers in vitro and in vivo,and contribute to the germlines of chimeras when injected into blastocysts.Androgenetic haploid stem cells can also be used in place of sperm to produce fertile progeny after intracytoplasmic injection into mature oocytes.Such characteristics demonstrate that haploid stem cells are a new approach for genetic studies at both the cellular and animal levels and that they are a valuable platform for future small molecule screening.

  16. All-trans-retinoic Acid Modulates the Plasticity and Inhibits the Motility of Breast Cancer Cells: ROLE OF NOTCH1 AND TRANSFORMING GROWTH FACTOR (TGFβ).

    Science.gov (United States)

    Zanetti, Adriana; Affatato, Roberta; Centritto, Floriana; Fratelli, Maddalena; Kurosaki, Mami; Barzago, Maria Monica; Bolis, Marco; Terao, Mineko; Garattini, Enrico; Paroni, Gabriela

    2015-07-17

    All-trans-retinoic acid (ATRA) is a natural compound proposed for the treatment/chemoprevention of breast cancer. Increasing evidence indicates that aberrant regulation of epithelial-to-mesenchymal transition (EMT) is a determinant of the cancer cell invasive and metastatic behavior. The effects of ATRA on EMT are largely unknown. In HER2-positive SKBR3 and UACC812 cells, showing co-amplification of the ERBB2 and RARA genes, ATRA activates a RARα-dependent epithelial differentiation program. In SKBR3 cells, this causes the formation/reorganization of adherens and tight junctions. Epithelial differentiation and augmented cell-cell contacts underlie the anti-migratory action exerted by the retinoid in cells exposed to the EMT-inducing factors EGF and heregulin-β1. Down-regulation of NOTCH1, an emerging EMT modulator, is involved in the inhibition of motility by ATRA. Indeed, the retinoid blocks NOTCH1 up-regulation by EGF and/or heregulin-β1. Pharmacological inhibition of γ-secretase and NOTCH1 processing also abrogates SKBR3 cell migration. Stimulation of TGFβ contributes to the anti-migratory effect of ATRA. The retinoid switches TGFβ from an EMT-inducing and pro-migratory determinant to an anti-migratory mediator. Inhibition of the NOTCH1 pathway not only plays a role in the anti-migratory action of ATRA; it is relevant also for the anti-proliferative activity of the retinoid in HCC1599 breast cancer cells, which are addicted to NOTCH1 for growth/viability. This effect is enhanced by the combination of ATRA and the γ-secretase inhibitor N-(N-(3,5-difluorophenacetyl)-l-alanyl)-S-phenylglycine t-butyl ester, supporting the concept that the two compounds act at the transcriptional and post-translational levels along the NOTCH1 pathway.

  17. C-terminal Src kinase-mediated EPIYA phosphorylation of Pragmin creates a feed-forward C-terminal Src kinase activation loop that promotes cell motility.

    Science.gov (United States)

    Senda, Yoshie; Murata-Kamiya, Naoko; Hatakeyama, Masanori

    2016-07-01

    Pragmin is one of the few mammalian proteins containing the Glu-Pro-Ile-Tyr-Ala (EPIYA) tyrosine-phosphorylation motif that was originally discovered in the Helicobacter pylori CagA oncoprotein. Following delivery into gastric epithelial cells by type IV secretion and subsequent tyrosine phosphorylation at the EPIYA motifs, CagA serves as an oncogenic scaffold/adaptor that promiscuously interacts with SH2 domain-containing mammalian proteins such as the Src homology 2 (SH2) domain-containing protein tyrosine phosphatase-2 (SHP2) and the C-terminal Src kinase (Csk), a negative regulator of Src family kinases. Like CagA, Pragmin also forms a physical complex with Csk. In the present study, we found that Pragmin directly binds to Csk by the tyrosine-phosphorylated EPIYA motif. The complex formation potentiates kinase activity of Csk, which in turn phosphorylates Pragmin on tyrosine-238 (Y238), Y343, and Y391. As Y391 of Pragmin comprises the EPIYA motif, Pragmin-Csk interaction creates a feed-forward regulatory loop of Csk activation. Together with the finding that Pragmin and Csk are colocalized to focal adhesions, these observations indicate that the Pragmin-Csk interaction, triggered by Pragmin EPIYA phosphorylation, robustly stimulates the kinase activity of Csk at focal adhesions, which direct cell-matrix adhesion that regulates cell morphology and cell motility. As a consequence, expression of Pragmin and/or Csk in epithelial cells induces an elongated cell shape with elevated cell scattering in a manner that is mutually dependent on Pragmin and Csk. Deregulation of the Pragmin-Csk axis may therefore induce aberrant cell migration that contributes to tumor invasion and metastasis. PMID:27116701

  18. Down regulation of genes involved in T cell polarity and motility during the induction of heart allograft tolerance by allochimeric MHC I.

    Directory of Open Access Journals (Sweden)

    Wojciech Lisik

    Full Text Available BACKGROUND: The allochimeric MHC class I molecule [alpha1h1/u]-RT1.Aa that contains donor-type (Wistar Furth, WF; RT1u epitopes displayed on recipient-type (ACI, RT1a administered in conjunction with sub-therapeutic dose of cyclosporine (CsA induces indefinite survival of heterotopic cardiac allografts in rat model. In vascularized transplantation models, the spleen contributes to graft rejection by generating alloantigen reactive T cells. The immune response in allograft rejection involves a cascade of molecular events leading to the formation of immunological synapses between T cells and the antigen-presenting cells. METHODOLOGY/PRINCIPAL FINDINGS: To elucidate the molecular pathways involved in the immunosuppressive function of allochimeric molecule we performed microarray and quantitative RTPCR analyses of gene expression profile of splenic T cells from untreated, CsA treated, and allochimeric molecule + subtherapeutic dose of CsA treated animals at day 1, 3 and 7 of post transplantation. Allochimeric molecule treatment caused down regulation of genes involved in actin filament polymerization (RhoA and Rac1, cell adhesion (Catna1, Vcam and CD9, vacuolar transport (RhoB, Cln8 and ATP6v1b2, and MAPK pathway (Spred1 and Dusp6 involved in tubulin cytoskeleton reorganization and interaction between actin and microtubule cytoskeleton. All these genes are involved in T cell polarity and motility, i.e., their ability to move, scan and to form functional immunological synapse with antigen presenting cells (APCs. CONCLUSIONS: These results indicate that the immunosuppressive function of allochimeric molecule may depend on the impairment of T cells' movement and scanning ability, and possibly also the formation of immunological synapse. We believe that these novel findings may have important clinical implications for organ transplantation.

  19. Regulation of thymocyte positive selection and motility by GIT2

    OpenAIRE

    Phee, Hyewon; Dzhagalov, Ivan; Mollenauer, Marianne; Wang, Yana; Irvine, Darrell J.; Robey, Ellen; Weiss, Arthur

    2010-01-01

    Thymocytes are highly motile cells that migrate under the influence of chemokines in distinct thymic compartments as they mature. The motility of thymocytes is tightly regulated; however, the molecular mechanisms that control thymocyte motility are not well understood. Here we report that G protein–coupled receptor kinase-interactor 2 (GIT2) was required for efficient positive selection. Notably, Git2−/− double-positive thymocytes showed greater activation of the small GTPase Rac, actin polym...

  20. [Obesity and gastrointestinal motility].

    Science.gov (United States)

    Lee, Joon Seong

    2006-08-01

    Gastrointestinal (GI) motility has a crucial role in the food consumption, digestion and absorption, and also controls the appetite and satiety. In obese patients, various alterations of GI motility have been investigated. The prevalence of GERD and esophageal motor disorders in obese patients are higher than those of general population. Gastric emptying of solid food is generally accelerated and fasting gastric volume especially in distal stomach is larger in obese patients without change in accommodation. Contractile activity of small intestine in fasting period is more prominent, but orocecal transit is delayed. Autonomic dysfunction is frequently demonstrated in obese patients. These findings correspond with increased appetite and delayed satiety in obese patients, but causes or results have not been confirmed. Therapeutic interventions of these altered GI motility have been developed using botulinum toxin, gastric electrical stimulation in obese patients. Novel agents targeted for GI hormone modulation (such as ghrelin and leptin) need to be developed in the near future. PMID:16929152

  1. PRL-3 promotes the motility, invasion, and metastasis of LoVo colon cancer cells through PRL-3-integrin β1-ERK1/2 and-MMP2 signaling

    Directory of Open Access Journals (Sweden)

    Wu Jian

    2009-11-01

    Full Text Available Abstract Background Phosphatase of regenerating liver-3 (PRL-3 plays a causative role in tumor metastasis, but the underlying mechanisms are not well understood. In our previous study, we observed that PRL-3 could decrease tyrosine phosphorylation of integrin β1 and enhance activation of ERK1/2 in HEK293 cells. Herein we aim to explore the association of PRL-3 with integrin β1 signaling and its functional implications in motility, invasion, and metastasis of colon cancer cell LoVo. Methods Transwell chamber assay and nude mouse model were used to study motility and invasion, and metastsis of LoVo colon cancer cells, respectively. Knockdown of integrin β1 by siRNA or lentivirus were detected with Western blot and RT-PCR. The effect of PRL-3 on integrin β1, ERK1/2, and MMPs that mediate motility, invasion, and metastasis were measured by Western blot, immunofluorencence, co-immunoprecipitation and zymographic assays. Results We demonstrated that PRL-3 associated with integrin β1 and its expression was positively correlated with ERK1/2 phosphorylation in colon cancer tissues. Depletion of integrin β1 with siRNA, not only abrogated the activation of ERK1/2 stimulated by PRL-3, but also abolished PRL-3-induced motility and invasion of LoVo cells in vitro. Similarly, inhibition of ERK1/2 phosphorylation with U0126 or MMP activity with GM6001 also impaired PRL-3-induced invasion. In addition, PRL-3 promoted gelatinolytic activity of MMP2, and this stimulation correlated with decreased TIMP2 expression. Moreover, PRL-3-stimulated lung metastasis of LoVo cells in a nude mouse model was inhibited when integrin β1 expression was interfered with shRNA. Conclusion Our results suggest that PRL-3's roles in motility, invasion, and metastasis in colon cancer are critically controlled by the integrin β1-ERK1/2-MMP2 signaling.

  2. Knockdown of Slit2 promotes growth and motility in gastric cancer cells via activation of AKT/β-catenin.

    Science.gov (United States)

    Shi, Rongliang; Yang, Zhen; Liu, Weiyan; Liu, Bingya; Xu, Ziping; Zhang, Ziping

    2014-02-01

    We previously showed that Slit2 was highly expressed in gastric cancer tissues that exhibit less advanced clinicopathological features, suggesting a tumor suppressor role for Slit2. In the present study, we investigated the effects of Slit2 knockdown on gastric cancer cells. Slit2-specific shRNAs were used to generate Slit2-knockdown SGC-7901 gastric cancer cells. Cell proliferation assay, Annexin V/PI double staining and cell cycle analysis were used to investigate the role of Slit2 knockdown in cell growth. Wound-healing and in vitro migration/invasion assays were performed. Subcutaneous tumor formation and peritoneal spreading in nude mice were employed to examine the in vivo effects of Slit2 knockdown. Cell signaling changes induced by Slit2 knockdown were analyzed by immunoblotting. Slit2 knockdown increased gastric cancer cell growth in monolayer and soft agar/Matrigel 3D culture. Slit2 knockdown inhibited apoptosis but did not alter cell cycle progression. Slit2-knockdown cells formed larger tumors and produced more peritoneal metastatic nodules in nude mice. Slit2 knockdown increased AKT phosphorylation, activated anti-apoptotic signaling, suppressed GSK3β activity and induced β-catenin activation. Blocking the effects of PI3K/AKT using pharmacological inhibitors abolished the ability of Slit2 knockdown to induce apoptosis resistance and cell migration/invasion. These results indicate that Slit2 knockdown promotes gastric cancer growth and metastasis through activation of the AKT/β‑catenin-mediated signaling pathway.

  3. The Hippo Pathway Effector YAP Regulates Motility, Invasion, and Castration-Resistant Growth of Prostate Cancer Cells

    OpenAIRE

    Lin ZHANG; Yang, Shuping; Chen, Xingcheng; Stauffer, Seth; Yu, Fang; Lele, Subodh M.; Fu, Kai; Datta, Kaustubh; Palermo, Nicholas; Chen, Yuanhong; Dong, Jixin

    2015-01-01

    Yes-associated protein (YAP) is an effector of the Hippo tumor suppressor pathway. The functional significance of YAP in prostate cancer has remained elusive. In this study, we first show that enhanced expression of YAP is able to transform immortalized prostate epithelial cells and promote migration and invasion in both immortalized and cancerous prostate cells. We found that YAP mRNA was upregulated in androgen-insensitive prostate cancer cells (LNCaP-C81 and LNCaP-C4-2 cells) compared to t...

  4. Transcriptional silencing of ETS-1 abrogates epithelial-mesenchymal transition resulting in reduced motility of pancreatic cancer cells.

    Science.gov (United States)

    Li, Chunyan; Wang, Zhonghan; Chen, Yan; Zhou, Min; Zhang, Haijun; Chen, Rong; Shi, Fangfang; Wang, Cailian; Rui, Zongdao

    2015-02-01

    v-ets erythroblastosis virus E26 oncogene homolog 1 (ETS-1) plays crucial roles in a spectrum of malignancies. ETS-1 has gained attention in cancer research for its importance in cell migration, invasion and proliferation. In the present study, we focused on the effect of ETS-1 on epithelial-mesenchymal transition (EMT), which is characterized by reduced E-cadherin expression and increased N-cadherin expression. We found that ETS-1 mRNA expression was positively correlated with N-cadherin and negatively correlated with E-cadherin mRNA expression in five pancreatic cancer cell lines. To elucidate the functionality of ETS-1 on EMT in pancreatic cancer cells, we constructed a green fluorescent protein (GFP)-expressing plasmid carrying ETS-1 short hairpin RNA (shRNA), and transfected Panc-1 cells with the plasmid. We detected reduced N-cadherin and vascular endothelial growth factor yet higher E-cadherin expression in the ETS-1-silenced cells compared with the control group. In addition, we observed reduced cell migration and increased adhesion in these cells. Our data showed that ETS-1 actively functioned as a regulator of EMT in Panc-1 cells, and provide additional evidence supporting a fundamental role for ETS-1 in metastatic pancreatic cancer cells. These results suggest that analysis of ETS-1 expression levels may provide an avenue for evaluating prognosis in pancreatic cancer.

  5. High-Content Screening for Quantitative Cell Biology.

    Science.gov (United States)

    Mattiazzi Usaj, Mojca; Styles, Erin B; Verster, Adrian J; Friesen, Helena; Boone, Charles; Andrews, Brenda J

    2016-08-01

    High-content screening (HCS), which combines automated fluorescence microscopy with quantitative image analysis, allows the acquisition of unbiased multiparametric data at the single cell level. This approach has been used to address diverse biological questions and identify a plethora of quantitative phenotypes of varying complexity in numerous different model systems. Here, we describe some recent applications of HCS, ranging from the identification of genes required for specific biological processes to the characterization of genetic interactions. We review the steps involved in the design of useful biological assays and automated image analysis, and describe major challenges associated with each. Additionally, we highlight emerging technologies and future challenges, and discuss how the field of HCS might be enhanced in the future.

  6. Neisseria meningitidis differentially controls host cell motility through PilC1 and PilC2 components of type IV Pili.

    Directory of Open Access Journals (Sweden)

    Philippe C Morand

    Full Text Available Neisseria meningitidis is a strictly human pathogen that has two facets since asymptomatic carriage can unpredictably turn into fulminant forms of infection. Meningococcal pathogenesis relies on the ability of the bacteria to break host epithelial or endothelial cellular barriers. Highly restrictive, yet poorly understood, mechanisms allow meningococcal adhesion to cells of only human origin. Adhesion of encapsulated and virulent meningococci to human cells relies on the expression of bacterial type four pili (T4P that trigger intense host cell signalling. Among the components of the meningococcal T4P, the concomitantly expressed PilC1 and PilC2 proteins regulate pili exposure at the bacterial surface, and until now, PilC1 was believed to be specifically responsible for T4P-mediated meningococcal adhesion to human cells. Contrary to previous reports, we show that, like PilC1, the meningococcal PilC2 component is capable of mediating adhesion to human ME180 epithelial cells, with cortical plaque formation and F-actin condensation. However, PilC1 and PilC2 promote different effects on infected cells. Cellular tracking analysis revealed that PilC1-expressing meningococci caused a severe reduction in the motility of infected cells, which was not the case when cells were infected with PilC2-expressing strains. The amount of both total and phosphorylated forms of EGFR was dramatically reduced in cells upon PilC1-mediated infection. In contrast, PilC2-mediated infection did not notably affect the EGFR pathway, and these specificities were shared among unrelated meningococcal strains. These results suggest that meningococci have evolved a highly discriminative tool for differential adhesion in specific microenvironments where different cell types are present. Moreover, the fine-tuning of cellular control through the combined action of two concomitantly expressed, but distinctly regulated, T4P-associated variants of the same molecule (i.e. PilC1 and Pil

  7. Flagellar motility confers epiphytic fitness advantages upon Pseudomonas syringae

    International Nuclear Information System (INIS)

    The role of flagellar motility in determining the epiphytic fitness of an ice-nucleation-active strain of Pseudomonas syringae was examined. The loss of flagellar motility reduced the epiphytic fitness of a normally motile P. syringae strain as measured by its growth, survival, and competitive ability on bean leaf surfaces. Equal population sizes of motile parental or nonmotile mutant P. syringae strains were maintained on bean plants for at least 5 days following the inoculation of fully expanded primary leaves. However, when bean seedlings were inoculated before the primary leaves had expanded and bacterial populations on these leaves were quantified at full expansion, the population size of the nonmotile derivative strain reached only 0.9% that of either the motile parental or revertant strain. When fully expanded bean primary leaves were coinoculated with equal numbers of motile and nonmotile cells, the population size of a nonmotile derivative strain was one-third of that of the motile parental or revertant strain after 8 days. Motile and nonmotile cells were exposed in vitro and on plants to UV radiation and desiccating conditions. The motile and nonmotile strains exhibited equal resistance to both stresses in vitro. However, the population size of a nonmotile strain on leaves was less than 20% that of a motile revertant strain when sampled immediately after UV irradiation. Epiphytic populations of both motile and nonmotile P. syringae declined under desiccating conditions on plants, and after 8 days, the population size of a nonmotile strain was less than one-third that of the motile parental or revertant strain

  8. Optical diagnostics of osteoblast cells and osteogenic drug screening

    Science.gov (United States)

    Kolanti, Elayaraja; Veerla, Sarath C.; Khajuria, Deepak K.; Roy Mahapatra, D.

    2016-02-01

    Microfluidic device based diagnostics involving optical fibre path, in situ imaging and spectroscopy are gaining importance due to recent advances in diagnostics instrumentation and methods, besides other factors such as low amount of reagent required for analysis, short investigation times, and potential possibilities to replace animal model based study in near future. It is possible to grow and monitor tissues in vitro in microfluidic lab-on-chip. It may become a transformative way of studying how cells interact with drugs, pathogens and biomaterials in physiologically relevant microenvironments. To a large extent, progress in developing clinically viable solutions has been constrained because of (i) contradiction between in vitro and in vivo results and (ii) animal model based and clinical studies which is very expensive. Our study here aims to evaluate the usefulness of microfluidic device based 3D tissue growth and monitoring approach to better emulate physiologically and clinically relevant microenvironments in comparison to conventional in vitro 2D culture. Moreover, the microfluidic methodology permits precise high-throughput investigations through real-time imaging while using very small amounts of reagents and cells. In the present study, we report on the details of an osteoblast cell based 3D microfluidic platform which we employ for osteogenic drug screening. The drug formulation is functionalized with fluorescence and other biomarkers for imaging and spectroscopy, respectively. Optical fibre coupled paths are used to obtain insight regarding the role of stress/flow pressure fluctuation and nanoparticle-drug concentration on the osteoblast growth and osteogenic properties of bone.

  9. A cell-based high-throughput screening assay for radiation susceptibility using automated cell counting

    International Nuclear Information System (INIS)

    Radiotherapy is one of the mainstays in the treatment for cancer, but its success can be limited due to inherent or acquired resistance. Mechanisms underlying radioresistance in various cancers are poorly understood and available radiosensitizers have shown only modest clinical benefit. There is thus a need to identify new targets and drugs for more effective sensitization of cancer cells to irradiation. Compound and RNA interference high-throughput screening technologies allow comprehensive enterprises to identify new agents and targets for radiosensitization. However, the gold standard assay to investigate radiosensitivity of cancer cells in vitro, the colony formation assay (CFA), is unsuitable for high-throughput screening. We developed a new high-throughput screening method for determining radiation susceptibility. Fast and uniform irradiation of batches up to 30 microplates was achieved using a Perspex container and a clinically employed linear accelerator. The readout was done by automated counting of fluorescently stained nuclei using the Acumen eX3 laser scanning cytometer. Assay performance was compared to that of the CFA and the CellTiter-Blue homogeneous uniform-well cell viability assay. The assay was validated in a whole-genome siRNA library screening setting using PC-3 prostate cancer cells. On 4 different cancer cell lines, the automated cell counting assay produced radiation dose response curves that followed a linear-quadratic equation and that exhibited a better correlation to the results of the CFA than did the cell viability assay. Moreover, the cell counting assay could be used to detect radiosensitization by silencing DNA-PKcs or by adding caffeine. In a high-throughput screening setting, using 4 Gy irradiated and control PC-3 cells, the effects of DNA-PKcs siRNA and non-targeting control siRNA could be clearly discriminated. We developed a simple assay for radiation susceptibility that can be used for high-throughput screening. This will aid

  10. The scaffolding protein NHERF1 sensitizes EGFR-dependent tumor growth, motility and invadopodia function to gefitinib treatment in breast cancer cells.

    Science.gov (United States)

    Bellizzi, Antonia; Greco, Maria Raffaella; Rubino, Rosa; Paradiso, Angelo; Forciniti, Stefania; Zeeberg, Katrine; Cardone, Rosa Angela; Reshkin, Stephan Joel

    2015-03-01

    Triple negative breast cancer (TNBC) patients cannot be treated with endocrine therapy or targeted therapies due to lack of related receptors. These patients overexpress the epidermal growth factor receptor (EGFR), but are resistant to tyrosine kinase inhibitors (TKIs) and anti-EGFR therapies. Mechanisms suggested for resistance to TKIs include EGFR independence, mutations and alterations in EGFR and in its downstream signalling pathways. Ligand-induced endocytosis and degradation of EGFR play important roles in the downregulation of the EGFR signal suggesting that its activity could be regulated by targeting its trafficking. Evidence in normal cells showing that the scaffolding protein Na+/H+ exchanger regulatory factor 1 (NHERF1) can associate with EGFR to regulate its trafficking, led us to hypothesize that NHERF1 expression levels could regulate EGFR trafficking and functional expression in TNBC cells and, in this way, modulate its role in progression and response to treatment. We investigated the subcellular localization of NHERF1 and its interaction with EGFR in a metastatic basal like TNBC cell model, MDA-MB‑231, and the role of forced NHERF1 overexpression and/or stimulation with EGF on the sensitivity to EGFR specific TKI treatment with gefitinib. Stimulation with EGF induces an interaction of NHERF1 with EGFR to regulate its localization, degradation and function. NHERF1 overexpression is sufficient to drive its interaction with EGFR in non-stimulated conditions, inhibits EGFR degradation and increases its retention time in the plasma membrane. Importantly, NHERF1 overexpression strongly sensitized the cell to the pharmacological inhibition by gefitinib of EGFR-driven growth, motility and invadopodia-dependent ECM proteolysis. The further determination of how the NHERF1‑EGFR interaction is regulated may improve our understanding of TNBC resistance to the action of existing anticancer drugs.

  11. Investigating Outer Hair Cell Motility with a Combination of External Alternating Electrical Field Stimulation and High-speed Image Analysis

    OpenAIRE

    Kitani, Rei; Kalinec, Federico

    2011-01-01

    OHCs are cylindrical sensorimotor cells located in the Organ of Corti, the auditory organ inside the mammalian inner ear. The name "hair cells" derives from their characteristic apical bundle of stereocilia, a critical element for detection and transduction of sound energy 1. OHCs are able to change shape —elongate, shorten and bend— in response to electrical, mechanical and chemical stimulation, a motor response considered crucial for cochlear amplification of acoustic signals 2.

  12. Cell-based phenotypic screening of mast cell degranulation unveils kinetic perturbations of agents targeting phosphorylation

    Science.gov (United States)

    Qin, Shenlu; Wang, Xumeng; Wu, Huanwen; Xiao, Peng; Cheng, Hongqiang; Zhang, Xue; Ke, Yuehai

    2016-01-01

    Mast cells play an essential role in initiating allergic diseases. The activation of mast cells are controlled by a complicated signal network of reversible phosphorylation, and finding the key regulators involved in this network has been the focus of the pharmaceutical industry. In this work, we used a method named Time-dependent cell responding profile (TCRP) to track the process of mast cell degranulation under various perturbations caused by agents targeting phosphorylation. To test the feasibility of this high-throughput cell-based phenotypic screening method, a variety of biological techniques were used. We further screened 145 inhibitors and clustered them based on the similarities of their TCRPs. Stat3 phosphorylation has been widely reported as a key step in mast cell degranulation. Interestingly, our TCRP results showed that a Stat3 inhibitor JSI124 did not inhibit degranulation like other Stat3 inhibitors, such as Stattic, clearly inhibited degranulation. Regular endpoint assays demonstrated that the distinctive TCRP of JSI124 potentially correlated with the ability to induce apoptosis. Consequently, different agents possibly have disparate functions, which can be conveniently detected by TCRP. From this perspective, our TCRP screening method is reliable and sensitive when it comes to discovering and selecting novel compounds for new drug developments. PMID:27502076

  13. Bistability in the Rac1, PAK, and RhoA Signaling Network Drives Actin Cytoskeleton Dynamics and Cell Motility Switches

    Science.gov (United States)

    Byrne, Kate M.; Monsefi, Naser; Dawson, John C.; Degasperi, Andrea; Bukowski-Wills, Jimi-Carlo; Volinsky, Natalia; Dobrzyński, Maciej; Birtwistle, Marc R.; Tsyganov, Mikhail A.; Kiyatkin, Anatoly; Kida, Katarzyna; Finch, Andrew J.; Carragher, Neil O.; Kolch, Walter; Nguyen, Lan K.; von Kriegsheim, Alex; Kholodenko, Boris N.

    2016-01-01

    Summary Dynamic interactions between RhoA and Rac1, members of the Rho small GTPase family, play a vital role in the control of cell migration. Using predictive mathematical modeling, mass spectrometry-based quantitation of network components, and experimental validation in MDA-MB-231 mesenchymal breast cancer cells, we show that a network containing Rac1, RhoA, and PAK family kinases can produce bistable, switch-like responses to a graded PAK inhibition. Using a small chemical inhibitor of PAK, we demonstrate that cellular RhoA and Rac1 activation levels respond in a history-dependent, bistable manner to PAK inhibition. Consequently, we show that downstream signaling, actin dynamics, and cell migration also behave in a bistable fashion, displaying switches and hysteresis in response to PAK inhibition. Our results demonstrate that PAK is a critical component in the Rac1-RhoA inhibitory crosstalk that governs bistable GTPase activity, cell morphology, and cell migration switches. PMID:27136688

  14. Effect of salinity and incubation time of planktonic cells on biofilm formation, motility, exoprotease production, and quorum sensing of Aeromonas hydrophila.

    Science.gov (United States)

    Jahid, Iqbal Kabir; Mizan, Md Furkanur Rahaman; Ha, Angela J; Ha, Sang-Do

    2015-08-01

    The aim of this study was to determine the effect of salinity and age of cultures on quorum sensing, exoprotease production, and biofilm formation by Aeromonas hydrophila on stainless steel (SS) and crab shell as substrates. Biofilm formation was assessed at various salinities, from fresh (0%) to saline water (3.0%). For young and old cultures, planktonic cells were grown at 30 °C for 24 h and 96 h, respectively. Biofilm formation was assessed on SS, glass, and crab shell; viable counts were determined in R2A agar for SS and glass, but Aeromonas-selective media was used for crab shell samples to eliminate bacterial contamination. Exoprotease activity was assessed using a Fluoro™ protease assay kit. Quantification of acyl-homoserine lactone (AHL) was performed using the bioreporter strain Chromobacterium violaceum CV026 and the concentration was confirmed using high-performance liquid chromatography (HPLC). The concentration of autoinducer-2 (AI-2) was determined with Vibrio harveyi BB170. The biofilm structure at various salinities (0-3 %) was assessed using field emission electron microscopy (FESEM). Young cultures of A. hydrophila grown at 0-0.25% salinity showed gradual increasing of biofilm formation on SS, glass and crab shell; swarming and swimming motility; exoproteases production, AHL and AI-2 quorum sensing; while all these phenotypic characters reduced from 0.5 to 3.0% salinity. The FESEM images also showed that from 0 to 0.25% salinity stimulated formation of three-dimensional biofilm structures that also broke through the surface by utilizing the chitin surfaces of crab, while 3% salinity stimulated attachment only for young cultures. However, in marked contrast, salinity (0.1-3%) had no effect on the stimulation of biofilm formation or on phenotypic characters for old cultures. However, all concentrations reduced biofilm formation, motility, protease production and quorum sensing for old culture. Overall, 0-0.25% salinity enhanced biofilm formation

  15. Droplet microfluidic technology for single-cell high-throughput screening

    OpenAIRE

    Brouzes, Eric; Medkova, Martina; Savenelli, Neal; Marran, Dave; Twardowski, Mariusz; Hutchison, J. Brian; Rothberg, Jonathan M.; Link, Darren R; Perrimon, Norbert; Samuels, Michael L

    2009-01-01

    We present a droplet-based microfluidic technology that enables high-throughput screening of single mammalian cells. This integrated platform allows for the encapsulation of single cells and reagents in independent aqueous microdroplets (1 pL to 10 nL volumes) dispersed in an immiscible carrier oil and enables the digital manipulation of these reactors at a very high-throughput. Here, we validate a full droplet screening workflow by conducting a droplet-based cytotoxicity screen. To perform t...

  16. Exopolysaccharide-independent social motility of Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Wei Hu

    Full Text Available Social motility (S motility, the coordinated movement of large cell groups on agar surfaces, of Myxococcus xanthus requires type IV pili (TFP and exopolysaccharides (EPS. Previous models proposed that this behavior, which only occurred within cell groups, requires cycles of TFP extension and retraction triggered by the close interaction of TFP with EPS. However, the curious observation that M. xanthus can perform TFP-dependent motility at a single-cell level when placed onto polystyrene surfaces in a highly viscous medium containing 1% methylcellulose indicated that "S motility" is not limited to group movements. In an apparent further challenge of the previous findings for S motility, mutants defective in EPS production were found to perform TFP-dependent motility on polystyrene surface in methylcellulose-containing medium. By exploring the interactions between pilin and surface materials, we found that the binding of TFP onto polystyrene surfaces eliminated the requirement for EPS in EPS(- cells and thus enabled TFP-dependent motility on a single cell level. However, the presence of a general anchoring surface in a viscous environment could not substitute for the role of cell surface EPS in group movement. Furthermore, EPS was found to serve as a self-produced anchoring substrate that can be shed onto surfaces to enable cells to conduct TFP-dependent motility regardless of surface properties. These results suggested that in certain environments, such as in methylcellulose solution, the cells could bypass the need for EPS to anchor their TPF and conduct single-cell S motility to promote exploratory movement of colonies over new specific surfaces.

  17. Genome-wide analysis in human colorectal cancer cells reveals ischemia-mediated expression of motility genes via DNA hypomethylation.

    Science.gov (United States)

    Skowronski, Karolina; Skowronki, Karolina; Andrews, Joseph; Rodenhiser, David I; Coomber, Brenda L

    2014-01-01

    DNA hypomethylation is an important epigenetic modification found to occur in many different cancer types, leading to the upregulation of previously silenced genes and loss of genomic stability. We previously demonstrated that hypoxia and hypoglycaemia (ischemia), two common micro-environmental changes in solid tumours, decrease DNA methylation through the downregulation of DNMTs in human colorectal cancer cells. Here, we utilized a genome-wide cross-platform approach to identify genes hypomethylated and upregulated by ischemia. Following exposure to hypoxia or hypoglycaemia, methylated DNA from human colorectal cancer cells (HCT116) was immunoprecipitated and analysed with an Affymetrix promoter array. Additionally, RNA was isolated and analysed in parallel with an Affymetrix expression array. Ingenuity pathway analysis software revealed that a significant proportion of the genes hypomethylated and upregulated were involved in cellular movement, including PLAUR and CYR61. A Matrigel invasion assay revealed that indeed HCT116 cells grown in hypoxic or hypoglycaemic conditions have increased mobility capabilities. Confirmation of upregulated expression of cellular movement genes was performed with qPCR. The correlation between ischemia and metastasis is well established in cancer progression, but the molecular mechanisms responsible for this common observation have not been clearly identified. Our novel data suggests that hypoxia and hypoglycaemia may be driving changes in DNA methylation through downregulation of DNMTs. This is the first report to our knowledge that provides an explanation for the increased metastatic potential seen in ischemic cells; i.e. that ischemia could be driving DNA hypomethylation and increasing expression of cellular movement genes.

  18. Effect of WFDC 2 silencing on the proliferation, motility and invasion of human serous ovarian cancer cells in vitro

    Institute of Scientific and Technical Information of China (English)

    Ya-Fei Zhu; Guo-Lan Gao; Sheng-Bo Tang; Zhen-Dong Zhang; Qing-Shui Huang

    2013-01-01

    Objective: To investigate effect and possible mechanisms of silencing human WFDC2 (HE4) gene on biological behavior changes as cell proliferation, apoptosis, movement and invasion of human serous ovarian cancer cell line SKOV3. Methods: Lentiviral WFDC2 gene sequence of small interfering siRNA was stablely transfected into SKOV3 identified by Q-PCR and western-blot. Obtained SKOV3 stable strains with silenced HE4 were measured by proliferation, apoptosis, migration, and invasion. Results: Gene sequencing showed that the oligonucleotides were successfully inserted into the expected site. After silencing HE4 in the SKOV3, proliferation was significantly inhibited (P<0.05). G0/G1 phase was arrested by the cell cycle (P<0.01) and capacity of the migration and invasion decreased significantly (P<0.01). Slight early apoptosis ratio and no change of late apoptosis were found without change of Caspase-3 or Bcl-2 protein. Proteins involed in ERK pathway as phosphorylated protein as p-EGFR, p- ERK decreased and protease protein involved in tissue remoding as matrix metalloproteinases MMP-9, MMP-2 and cathepsin B decreased compared with control group. Conclusions: HE4 gene plays an important role in regulating proliferation, apoptosis, migration, invasion of serous ovarian cancer cells by ERK pathway and protease system. Its role in apoptosis needs to be further explored, and it may be a potential target for serous ovarian cancer.

  19. A Versatile Cell Death Screening Assay Using Dye-Stained Cells and Multivariate Image Analysis.

    Science.gov (United States)

    Collins, Tony J; Ylanko, Jarkko; Geng, Fei; Andrews, David W

    2015-11-01

    A novel dye-based method for measuring cell death in image-based screens is presented. Unlike conventional high- and medium-throughput cell death assays that measure only one form of cell death accurately, using multivariate analysis of micrographs of cells stained with the inexpensive mix, red dye nonyl acridine orange, and a nuclear stain, it was possible to quantify cell death induced by a variety of different agonists even without a positive control. Surprisingly, using a single known cytotoxic agent as a positive control for training a multivariate classifier allowed accurate quantification of cytotoxicity for mechanistically unrelated compounds enabling generation of dose-response curves. Comparison with low throughput biochemical methods suggested that cell death was accurately distinguished from cell stress induced by low concentrations of the bioactive compounds Tunicamycin and Brefeldin A. High-throughput image-based format analyses of more than 300 kinase inhibitors correctly identified 11 as cytotoxic with only 1 false positive. The simplicity and robustness of this dye-based assay makes it particularly suited to live cell screening for toxic compounds.

  20. Pattern formation mechanisms in motility mutants of Myxococcus xanthus

    CERN Document Server

    Starruss, Joern; Jakovljevic, Vladimir; Sogaard-Andersen, Lotte; Deutsch, Andreas; Baer, Markus

    2016-01-01

    Formation of spatial patterns of cells is a recurring theme in biology and often depends on regulated cell motility. Motility of M. xanthus depends on two motility machineries: the S-engine and A-engine. Moving M. xanthus cells can organize into spreading colonies or spore-filled fruiting bodies depending on their nutritional status. To understand these two pattern formation processes and the contributions by the two motility machineries, as well as cell reversal, we analyze spatial self-organization in 3 strains: i) a mutant that moves unidirectionally without reversing by the A-motility system only, ii) a unidirectional mutant that is also equipped with the S-motility system, and iii) the wild-type that, in addition to the two motility systems, reverses its direction of movement. The mutant moving by the A-engine illustrates that collective motion in the form of large moving clusters can arise in gliding bacteria due to steric interactions of the rod-shaped cells, without the need of invoking any biochemica...

  1. Active screen plasma nitriding enhances cell attachment to polymer surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kaklamani, Georgia, E-mail: g.kaklamani@bham.ac.uk [University of Birmingham, College of Engineering and Physical Sciences, School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom); Bowen, James; Mehrban, Nazia [University of Birmingham, College of Engineering and Physical Sciences, School of Chemical Engineering, Edgbaston, Birmingham B15 2TT (United Kingdom); Dong, Hanshan [University of Birmingham, College of Engineering and Physical Sciences, School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom); Grover, Liam M. [University of Birmingham, College of Engineering and Physical Sciences, School of Chemical Engineering, Edgbaston, Birmingham B15 2TT (United Kingdom); Stamboulis, Artemis [University of Birmingham, College of Engineering and Physical Sciences, School of Metallurgy and Materials, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2013-05-15

    Active screen plasma nitriding (ASPN) is a well-established technique used for the surface modification of materials, the result of which is often a product with enhanced functional performance. Here we report the modification of the chemical and mechanical properties of ultra-high molecular weight poly(ethylene) (UHMWPE) using 80:20 (v/v) N{sub 2}/H{sub 2} ASPN, followed by growth of 3T3 fibroblasts on the treated and untreated polymer surfaces. ASPN-treated UHMWPE showed extensive fibroblast attachment within 3 h of seeding, whereas fibroblasts did not successfully attach to untreated UHMWPE. Fibroblast-coated surfaces were maintained for up to 28 days, monitoring their metabolic activity and morphology throughout. The chemical properties of the ASPN-treated UHMWPE surface were studied using X-ray photoelectron spectroscopy, revealing the presence of C-N, C=N, and C≡N chemical bonds. The elastic modulus, surface topography, and adhesion properties of the ASPN-treated UHMWPE surface were studied over 28 days during sample storage under ambient conditions and during immersion in two commonly used cell culture media.

  2. Electroacupuncture Regulates Apoptosis/Proliferation of Intramuscular Interstitial Cells of Cajal and Restores Colonic Motility in Diabetic Constipation Rats

    Directory of Open Access Journals (Sweden)

    Juanjuan Xu

    2013-01-01

    Full Text Available Injury of interstitial cells of Cajal (ICC is associated with gut dysmotility in diabetic rats. We have shown an acceleration of the colonic contractility by electroacupuncture stimulation (EAS. However, little is known about potential roles of EAS on colonic transit and ICC. In this study, we evaluate the effect of EAS on colonic transit and investigate whether apoptosis/proliferation of ICC was involved in regulative effect of EAS on colonic transit. Rats were randomly assigned to normal, diabetic, diabetic-plus-sham stimulation, diabetic-plus-low-frequency stimulation, and diabetic-plus-high-frequency stimulation groups. Bead expulsion test was used for measuring the distal colonic transit. The Kit (ICC marker was detected by western blot. Apoptotic ICC was detected by terminal dUTP nucleotide end labeling. Proliferating ICC was identified by Kit/Ki67 double immunofluorescent staining on whole mount preparations. Ultrastructure changes of ICC were studied using electron microscopy. Results showed that high-frequency stimulation significantly promoted colonic transit. Low- and high-frequency stimulation markedly rescued intramuscular ICC from apoptosis. Abundant proliferating intramuscular ICC was found in low- and high-frequency stimulation groups. Our results indicate that high-frequency EAS has stimulatory effect on the distal colonic transit, which may be mediated by downregulation of the apoptosis and upregulation of the proliferation of intramuscular ICC.

  3. Human hepatocytes derived from pluripotent stem cells: a promising cell model for drug hepatotoxicity screening.

    Science.gov (United States)

    Gómez-Lechón, María José; Tolosa, Laia

    2016-09-01

    Drug-induced liver injury (DILI) is a frequent cause of failure in both clinical and post-approval stages of drug development, and poses a key challenge to the pharmaceutical industry. Current animal models offer poor prediction of human DILI. Although several human cell-based models have been proposed for the detection of human DILI, human primary hepatocytes remain the gold standard for preclinical toxicological screening. However, their use is hindered by their limited availability, variability and phenotypic instability. In contrast, pluripotent stem cells, which include embryonic and induced pluripotent stem cells (iPSCs), proliferate extensively in vitro and can be differentiated into hepatocytes by the addition of soluble factors. This provides a stable source of hepatocytes for multiple applications, including early preclinical hepatotoxicity screening. In addition, iPSCs also have the potential to establish genotype-specific cells from different individuals, which would increase the predictivity of toxicity assays allowing more successful clinical trials. Therefore, the generation of human hepatocyte-like cells derived from pluripotent stem cells seems to be promising for overcoming limitations of hepatocyte preparations, and it is expected to have a substantial repercussion in preclinical hepatotoxicity risk assessment in early drug development stages. PMID:27325232

  4. Swimming Motility Reduces Deposition to Silica Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Nanxi [Univ. of Illinois, Urbana-Champaign, IL (United States); Massoudieh, Arash [The Catholic Univ. of America, Washington, DC (United States); Liang, Xiaomeng [The Catholic Univ. of America, Washington, DC (United States); Hu, Dehong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kamai, Tamir [Agricultural Research Organization, Bet Dagan (Israel); Ginn, Timothy R. [Univ. of California, Davis, CA (United States); Zilles, Julie L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Nguyen, Thanh H. [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2015-01-01

    The role of swimming motility on bacterial transport and fate in porous media was evaluated. We present microscopic evidence showing that strong swimming motility reduces attachment of Azotobacter vinelandii cells to silica surfaces. Applying global and cluster statistical analyses to microscopic videos taken under non-flow conditions, wild type, flagellated A. vinelandii strain DJ showed strong swimming ability with an average speed of 13.1 μm/s, DJ77 showed impaired swimming averaged at 8.7 μm/s, and both the non-flagellated JZ52 and chemically treated DJ cells were non-motile. Quantitative analyses of trajectories observed at different distances above the collector of a radial stagnation point flow cell (RSPF) revealed that both swimming and non-swimming cells moved with the flow when at a distance of at least 20 μm from the collector surface. Near the surface, DJ cells showed both horizontal and vertical movement diverging them from reaching surfaces, while chemically treated DJ cells moved with the flow to reach surfaces, suggesting that strong swimming reduced attachment. In agreement with the RSPF results, the deposition rates obtained for two-dimensional multiple-collector micromodels were also lowest for DJ, while DJ77 and JZ52 showed similar values. Strong swimming specifically reduced deposition on the upstream surfaces of the micromodel collectors.

  5. Cell motility in models of wounded human skin is improved by Gap27 despite raised glucose, insulin and IGFBP-5

    International Nuclear Information System (INIS)

    Reducing Cx43 expression stimulates skin wound healing. This is mimicked in models when Cx43 function is blocked by the connexin mimetic peptide Gap27. IGF-I also stimulates wound healing with IGFBP-5 attenuating its actions. Further, the IGF-I to IGFBP-5 ratio is altered in diabetic skin, where wound closure is impaired. We investigated whether Gap27 remains effective in augmenting scrape-wound closure in human skin wound models simulating diabetes-induced changes, using culture conditions with raised glucose, insulin and IGFBP-5. Gap27 increased scrape-wound closure in normal glucose and insulin (NGI) and to a lesser extent in high glucose and insulin (HGI). IGF-I enhanced scrape-wound closure in keratinocytes whereas IGFBP-5 inhibited this response. Gap27 overcame the inhibitory effects of IGFBP-5 on IGF-I activity. Connexin-mediated communication (CMC) was reduced in HGI, despite raised Cx43, and Gap27 significantly decreased CMC in NGI and HGI. IGF-I and IGFBP-5 did not affect CMC. IGF-I increased keratinocyte proliferation in NGI, and Gap27 increased proliferation in NGI to a greater extent than in HGI. We conclude that IGF-I and Gap27 stimulate scrape-wound closure by independent mechanisms with Gap27 inhibiting Cx43 function. Gap27 can enhance wound closure in diabetic conditions, irrespective of the IGF-I:IGFBP-5 balance. - Highlights: ► Human organotypic and keratinocyte ‘diabetic’ skin models were used to demonstrate the ability of Gap27 to improve scrape-wound closure. ► Gap27 enhanced scrape-wound closure by reducing Cx43-mediated communication, whereas IGFBP-5 retarded cell migration. ► IGF-I and IGFBP-5 did not affect connexin-mediated pathways. ► Gap27 can override altered glucose, insulin, IGF-I, and IGFBP-5 in ‘diabetic’ skin models and thus has therapeutic potential

  6. Cell motility in models of wounded human skin is improved by Gap27 despite raised glucose, insulin and IGFBP-5

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Catherine S.; Berends, Rebecca F. [Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA (United Kingdom); Flint, David J. [Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE (United Kingdom); Martin, Patricia E.M., E-mail: Patricia.Martin@gcu.ac.uk [Department of Life Sciences, School of Health and Life Sciences, Glasgow Caledonian University, 70 Cowcaddens Road, Glasgow G4 0BA (United Kingdom)

    2013-02-15

    Reducing Cx43 expression stimulates skin wound healing. This is mimicked in models when Cx43 function is blocked by the connexin mimetic peptide Gap27. IGF-I also stimulates wound healing with IGFBP-5 attenuating its actions. Further, the IGF-I to IGFBP-5 ratio is altered in diabetic skin, where wound closure is impaired. We investigated whether Gap27 remains effective in augmenting scrape-wound closure in human skin wound models simulating diabetes-induced changes, using culture conditions with raised glucose, insulin and IGFBP-5. Gap27 increased scrape-wound closure in normal glucose and insulin (NGI) and to a lesser extent in high glucose and insulin (HGI). IGF-I enhanced scrape-wound closure in keratinocytes whereas IGFBP-5 inhibited this response. Gap27 overcame the inhibitory effects of IGFBP-5 on IGF-I activity. Connexin-mediated communication (CMC) was reduced in HGI, despite raised Cx43, and Gap27 significantly decreased CMC in NGI and HGI. IGF-I and IGFBP-5 did not affect CMC. IGF-I increased keratinocyte proliferation in NGI, and Gap27 increased proliferation in NGI to a greater extent than in HGI. We conclude that IGF-I and Gap27 stimulate scrape-wound closure by independent mechanisms with Gap27 inhibiting Cx43 function. Gap27 can enhance wound closure in diabetic conditions, irrespective of the IGF-I:IGFBP-5 balance. - Highlights: ► Human organotypic and keratinocyte ‘diabetic’ skin models were used to demonstrate the ability of Gap27 to improve scrape-wound closure. ► Gap27 enhanced scrape-wound closure by reducing Cx43-mediated communication, whereas IGFBP-5 retarded cell migration. ► IGF-I and IGFBP-5 did not affect connexin-mediated pathways. ► Gap27 can override altered glucose, insulin, IGF-I, and IGFBP-5 in ‘diabetic’ skin models and thus has therapeutic potential.

  7. Single-cell analysis of population context advances RNAi screening at multiple levels

    NARCIS (Netherlands)

    Snijder, Berend; Sacher, Raphael; Rämö, Pauli; Liberali, Prisca; Mench, Karin; Wolfrum, Nina; Burleigh, Laura; Scott, Cameron C; Verheije, Monique H; Mercer, Jason; Moese, Stefan; Heger, Thomas; Theusner, Kristina; Jurgeit, Andreas; Lamparter, David; Balistreri, Giuseppe; Schelhaas, Mario; De Haan, Cornelis A M; Marjomäki, Varpu; Hyypiä, Timo; Rottier, Peter J M; Sodeik, Beate; Marsh, Mark; Gruenberg, Jean; Amara, Ali; Greber, Urs; Helenius, Ari; Pelkmans, Lucas

    2012-01-01

    Isogenic cells in culture show strong variability, which arises from dynamic adaptations to the microenvironment of individual cells. Here we study the influence of the cell population context, which determines a single cell's microenvironment, in image-based RNAi screens. We developed a comprehensi

  8. Microalgal motility measurement microfluidic chip for toxicity assessment of heavy metals

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Guoxia [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Department of Biotechnology, Dalian, Liaoning (China); Dalian University, Dalian, Liaoning (China); Wang, Yunhua [Dalian University, Dalian, Liaoning (China); Qin, Jianhua [Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Department of Biotechnology, Dalian, Liaoning (China)

    2012-12-15

    A polydimethylsiloxane microfluidic chip has been developed for the estimation of toxic heavy metals based on measurement of mobility of marine microalgae. The chip is mainly composed of an upstream concentration gradient generator and a downstream perfusion-based chemotatic module. The processes of toxic liquid dilution and diffusion, microalgal culturing, cell stimulation, and online screening can be integrated in this chip, which makes it an attractive approach to simplify toxicity testing procedures. The microalgal motility was adopted as a microfluidic bioassay signal and was evaluated as the percentage of motile cells, curvilinear velocity, average path velocity, and straight line velocity. Two mobile marine microalgae, Platymonas subcordiformis and Platymonas helgolandica var. tsingtaoensis, were confined in the chemotatic module and stimulated by the eight concentration gradients of Cu and Cd generated by the concentration gradient generator. In all cases, a toxic response was detected (i.e., a dose-related inhibition of motility was observed). Only 1.5 h was needed to predict EC{sub 50} values. Thus, the microfluidic chip developed was proved to be useful as a simple and rapid approach in heavy metal detection and might be expanded as a conventional test method in environmental toxicity assessment. (orig.)

  9. Screening and identification of a specific peptide for targeting hypoxic hepatoma cells.

    Science.gov (United States)

    Liu, Yiming; Xia, Xiangwen; Wang, Yong; Li, Xin; Zhou, Guofeng; Liang, Huiming; Feng, Gansheng; Zheng, Chuansheng

    2016-08-01

    The biological behaviors of residual hepatoma cells after transarterial embolization therapy, which exist in a hypoxic or even anaerobic tumor microenvironment, differ from the tumor cells under normoxic conditions. This study aimed to use a phage display peptide library for in vivo and in vitro screening to obtain a peptide which could specifically bind to hypoxic hepatoma cells, allowing further targeted diagnosis and treatment for liver cancer. In this study, hypoxic hepatoma cells HepG2 (targeted cells), and normal liver cells HL-7702 (control cells), were utilized to perform three rounds of in vitro screening using a phage-displayed 7-mer peptide library. In addition, hypoxic HepG2 were subcutaneously injected into nude mice to establish a hepatocarcinoma model, followed by performing three rounds of in vivo screening on the phages identified from the in vitro screening. The products from the screening were further identified using ELISA and immunofluorescence staining on cells and tissues. The results indicated that the P11 positive clone had the highest binding effect with hypoxic hepatoma cells. The sequence of the exogenous insert fragment of P11 positive clone was obtained by sequencing: GSTSFSK. The binding assay indicated that GSTSFSK could specifically bind to hypoxic hepatoma cells and hepatocarcinoma tissues. This 7-mer peptide has the potential to be developed as an useful molecular to the targeting diagnosis and treatment of residual hepatoma cells after transarterial chemoembolization. PMID:27381416

  10. Flagellar Motility of Trypanosoma cruzi Epimastigotes

    Directory of Open Access Journals (Sweden)

    G. Ballesteros-Rodea

    2012-01-01

    Full Text Available The hemoflagellate Trypanosoma cruzi is the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known about T. cruzi motility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

  11. Stem cells: a model for screening, discovery and development of drugs

    Directory of Open Access Journals (Sweden)

    Kitambi SS

    2011-09-01

    Full Text Available Satish Srinivas Kitambi1, Gayathri Chandrasekar21Department of Medical Biochemistry and Biophysics; 2Department of Biosciences, Karolinska Institutet, Stockholm, SwedenAbstract: The identification of normal and cancerous stem cells and the recent advances made in isolation and culture of stem cells have rapidly gained attention in the field of drug discovery and regenerative medicine. The prospect of performing screens aimed at proliferation, directed differentiation, and toxicity and efficacy studies using stem cells offers a reliable platform for the drug discovery process. Advances made in the generation of induced pluripotent stem cells from normal or diseased tissue serves as a platform to perform drug screens aimed at developing cell-based therapies against conditions like Parkinson's disease and diabetes. This review discusses the application of stem cells and cancer stem cells in drug screening and their role in complementing, reducing, and replacing animal testing. In addition to this, target identification and major advances in the field of personalized medicine using induced pluripotent cells are also discussed.Keywords: therapeutics, stem cells, cancer stem cells, screening models, drug development, high throughput screening

  12. Metastasis Is Cell Motility Disease

    Institute of Scientific and Technical Information of China (English)

    Kazuyuki ITOH

    2009-01-01

    @@ Multidisciplinary approach (surgery, chemotherapy and radiation) for the primary site of cancer is now almost established, however, recurrence, inva-sion and metastasis are still life threatening, thus the effort of fighting against metastasis is critical and crucial.

  13. Model for self-polarization and motility of keratocyte fragments

    KAUST Repository

    Ziebert, F.

    2011-10-19

    Computational modelling of cell motility on substrates is a formidable challenge; regulatory pathways are intertwined and forces that influence cell motion are not fully quantified. Additional challenges arise from the need to describe a moving deformable cell boundary. Here, we present a simple mathematical model coupling cell shape dynamics, treated by the phase-field approach, to a vector field describing the mean orientation (polarization) of the actin filament network. The model successfully reproduces the primary phenomenology of cell motility: discontinuous onset of motion, diversity of cell shapes and shape oscillations. The results are in qualitative agreement with recent experiments on motility of keratocyte cells and cell fragments. The asymmetry of the shapes is captured to a large extent in this simple model, which may prove useful for the interpretation of experiments.

  14. New advances in gastrointestinal motility research

    CERN Document Server

    Pullan, A; Farrugia, G

    2013-01-01

    Research into gastrointestinal motility has received renewed interest in part due to recent advances in the techniques for measuring the structure and function of gastrointestinal cells, tissue and organs. The integration of this wealth of data into biophysically based computation models can aid in interpretation of experimental and clinical measurements and the refinement of measurement techniques. The contents of this book span multiple scales - from cell, tissue, organ, to whole body and is divided into four broad sections covering: i) gastrointestinal cellular activity and tissue structure; (ii) techniques for measuring, analyzing and visualizing high-resolution extra-cellular recordings; (iii) methods for sensing gastroelectrical activity using non-invasive bio-electro-magnetic fields and for modulating the underlying gastric electrical activity, and finally; (iv) methods for assessing manometric and videographic motility patterns and the application of these data for predicting the flow and mixing behav...

  15. Symbiosis and the origin of eukaryotic motility

    Science.gov (United States)

    Margulis, L.; Hinkle, G.

    1991-01-01

    Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the serial endosymbiotic theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.

  16. Women's attitude towards prenatal screening for red blood cell antibodies, other than RhD

    Directory of Open Access Journals (Sweden)

    van der Schoot CE

    2008-11-01

    Full Text Available Abstract Background Since July 1998 all Dutch women (± 200,000/y are screened for red cell antibodies, other than anti-RhesusD (RhD in the first trimester of pregnancy, to facilitate timely treatment of pregnancies at risk for hemolytic disease of the fetus and newborn (HDFN. Evidence for benefits, consequences and costs of screening for non-RhD antibodies is still under discussion. The screening program was evaluated in a nation-wide study. As a part of this evaluation study we investigated, according to the sixth criterium of Wilson and Jüngner, the acceptance by pregnant women of the screening program for non-RhD antibodies. Methods Controlled longitudinal survey, including a prenatal and a postnatal measurement by structured questionnaires. Main outcome measures: information satisfaction, anxiety during the screening process (a.o. STAI state inventory and specific questionnaire modules, overall attitude on the screening program. Univariate analysis was followed by standard multivariate analysis to identify significant predictors of the outcome measures. Participants: 233 pregnant women, distributed over five groups, according to the screening result. Results Satisfaction about the provided information was moderate in all groups. All screen- positive groups desired more supportive information. Anxiety increased in screen- positives during the screening process, but decreased to basic levels postnatally. All groups showed a strongly positive balance between perceived utility and burden of the screening program, independent on test results or background characteristics. Conclusion Women highly accept the non-RhD antibody screening program. However, satisfaction about provided information is moderate. Oral and written information should be provided by obstetric care workers themselves, especially to screen-positive women.

  17. Tubulin tyrosine ligase-like genes ttll3 and ttll6 maintain zebrafish cilia structure and motility.

    Science.gov (United States)

    Pathak, Narendra; Austin, Christina A; Drummond, Iain A

    2011-04-01

    Tubulin post-translational modifications generate microtubule heterogeneity and modulate microtubule function, and are catalyzed by tubulin tyrosine ligase-like (TTLL) proteins. Using antibodies specific to monoglycylated, polyglycylated, and glutamylated tubulin in whole mount immunostaining of zebrafish embryos, we observed distinct, tissue-specific patterns of tubulin modifications. Tubulin modification patterns in cilia correlated with the expression of ttll3 and ttll6 in ciliated cells. Expression screening of all zebrafish tubulin tyrosine ligase-like genes revealed additional tissue-specific expression of ttll1 in brain neurons, ttll4 in muscle, and ttll7 in otic placodes. Knockdown of ttll3 eliminated cilia tubulin glycylation but had surprisingly mild effects on cilia structure and motility. Similarly, knockdown of ttll6 strongly reduced cilia tubulin glutamylation but only partially affected cilia structure and motility. Combined loss of function of ttll3 and ttll6 caused near complete loss of cilia motility and induced a variety of axonemal ultrastructural defects similar to defects previously observed in zebrafish fleer mutants, which were shown to lack tubulin glutamylation. Consistently, we find that fleer mutants also lack tubulin glycylation. These results indicate that tubulin glycylation and glutamylation have overlapping functions in maintaining cilia structure and motility and that the fleer/dyf-1 TPR protein is required for both types of tubulin post-translational modification. PMID:21262966

  18. Screening for Stromal and Matrix Effects in 3D Microenvironments of Breast Cancer Cells

    Science.gov (United States)

    Montanez-Sauri, Sara I.

    Breast cancer progression ensures through the acquisition of genetic mutations, the uncontrollable growth of cells, and their progression to invasion. Studies have shown that the surrounding three-dimensional (3D) microenvironment can also influence breast cancer cell progression by controlling the morphology, differentiation, proliferation, and migration of cells. However, most of the currently available in vitro screening platforms are based on the two-dimensional (2D) culture of cells, and do not provide cells with the complex 3D microenvironment that exists in vivo. Therefore, there is a need for more biologically relevant in vitro platforms to help decipher the complexity of the microenvironment and its influence in breast cancer. In this dissertation we present an automated microfluidic platform that allows to efficiently screen for the effect of multiple matrix and stromal microenvironment in 3D cultures of breast cancer cells. Several extracellular matrix (ECM) compositions and stromal cells are included in the 3D microenvironments to examine their influence on breast cancer cell behavior. The screening results suggest that collagen gels with fibronectin might be influencing paracrine signals between breast cancer cells and stromal cells. The ability of the platform to culture and treat cells in 3D microenvironments offers a powerful screening tool for the identification of compounds and interactions using more in vivo-like 3D microenvironments. The identification of these mechanisms will increase our current understanding of breast cancer, and will aid in the identification of potential therapeutics.

  19. A protein network-guided screen for cell cycle regulators in Drosophila

    Directory of Open Access Journals (Sweden)

    Kashat Maria A

    2011-05-01

    Full Text Available Abstract Background Large-scale RNAi-based screens are playing a critical role in defining sets of genes that regulate specific cellular processes. Numerous screens have been completed and in some cases more than one screen has examined the same cellular process, enabling a direct comparison of the genes identified in separate screens. Surprisingly, the overlap observed between the results of similar screens is low, suggesting that RNAi screens have relatively high levels of false positives, false negatives, or both. Results We re-examined genes that were identified in two previous RNAi-based cell cycle screens to identify potential false positives and false negatives. We were able to confirm many of the originally observed phenotypes and to reveal many likely false positives. To identify potential false negatives from the previous screens, we used protein interaction networks to select genes for re-screening. We demonstrate cell cycle phenotypes for a significant number of these genes and show that the protein interaction network is an efficient predictor of new cell cycle regulators. Combining our results with the results of the previous screens identified a group of validated, high-confidence cell cycle/cell survival regulators. Examination of the subset of genes from this group that regulate the G1/S cell cycle transition revealed the presence of multiple members of three structurally related protein complexes: the eukaryotic translation initiation factor 3 (eIF3 complex, the COP9 signalosome, and the proteasome lid. Using a combinatorial RNAi approach, we show that while all three of these complexes are required for Cdk2/Cyclin E activity, the eIF3 complex is specifically required for some other step that limits the G1/S cell cycle transition. Conclusions Our results show that false positives and false negatives each play a significant role in the lack of overlap that is observed between similar large-scale RNAi-based screens. Our results

  20. Live Cell Microscopy-Based RNAi Screening in the Moss Physcomitrella patens.

    Science.gov (United States)

    Miki, Tomohiro; Nakaoka, Yuki; Goshima, Gohta

    2016-01-01

    RNA interference (RNAi) is a powerful technique enabling the identification of the genes involved in a certain cellular process. Here, we discuss protocols for microscopy-based RNAi screening in protonemal cells of the moss Physcomitrella patens, an emerging model system for plant cell biology. Our method is characterized by the use of conditional (inducible) RNAi vectors, transgenic moss lines in which the RNAi vector is integrated, and time-lapse fluorescent microscopy. This method allows for effective and efficient screening of >100 genes involved in various cellular processes such as mitotic cell division, organelle distribution, or cell growth. PMID:27581297

  1. Mutations in the Borrelia burgdorferi Flagellar Type III Secretion System Genes fliH and fliI Profoundly Affect Spirochete Flagellar Assembly, Morphology, Motility, Structure, and Cell Division

    Science.gov (United States)

    Gao, Lihui; Zhao, Xiaowei; Liu, Jun; Norris, Steven J.

    2015-01-01

    ABSTRACT The Lyme disease spirochete Borrelia burgdorferi migrates to distant sites in the tick vectors and mammalian hosts through robust motility and chemotaxis activities. FliH and FliI are two cytoplasmic proteins that play important roles in the type III secretion system (T3SS)-mediated export and assembly of flagellar structural proteins. However, detailed analyses of the roles of FliH and FliI in B. burgdorferi have not been reported. In this study, fliH and fliI transposon mutants were utilized to dissect the mechanism of the Borrelia type III secretion system. The fliH and fliI mutants exhibited rod-shaped or string-like morphology, greatly reduced motility, division defects (resulting in elongated organisms with incomplete division points), and noninfectivity in mice by needle inoculation. Mutants in fliH and fliI were incapable of translational motion in 1% methylcellulose or soft agar. Inactivation of either fliH or fliI resulted in the loss of the FliH-FliI complex from otherwise intact flagellar motors, as determined by cryo-electron tomography (cryo-ET). Flagellar assemblies were still present in the mutant cells, albeit in lower numbers than in wild-type cells and with truncated flagella. Genetic complementation of fliH and fliI mutants in trans restored their wild-type morphology, motility, and flagellar motor structure; however, full-length flagella and infectivity were not recovered in these complemented mutants. Based on these results, disruption of either fliH or fliI in B. burgdorferi results in a severe defect in flagellar structure and function and cell division but does not completely block the export and assembly of flagellar hook and filament proteins. PMID:25968649

  2. Autophagy-related proteins are functionally active in human spermatozoa and may be involved in the regulation of cell survival and motility

    Science.gov (United States)

    Aparicio, I. M.; Espino, J.; Bejarano, I.; Gallardo-Soler, A.; Campo, M. L.; Salido, G. M.; Pariente, J. A.; Peña, F. J.; Tapia, J. A.

    2016-01-01

    Macroautophagy (hereafter autophagy) is an evolutionarily highly conserved cellular process that participates in the maintenance of intracellular homeostasis through the degradation of most long-lived proteins and entire organelles. Autophagy participates in some reproductive events; however, there are not reports regarding the role of autophagy in the regulation of sperm physiology. Hence, the aim of this study was to investigate whether autophagy-related proteins are present and functionally active in human spermatozoa. Proteins related to autophagy/mitophagy process (LC3, Atg5, Atg16, Beclin 1, p62, m-TOR, AMPKα 1/2, and PINK1) were present in human spermatozoa. LC3 colocalized with p62 in the middle piece of the spermatozoa. Autophagy activation induced a significant increase in motility and a decrease in PINK1, TOM20 expression and caspase 3/7 activation. In contrast, autophagy inhibition resulted in decreased motility, viability, ATP and intracellular calcium concentration whereas PINK1, TOM20 expression, AMPK phosphorylation and caspase 3/7 activation were significantly increased. In conclusion our results show that autophagy related proteins and upstream regulators are present and functional in human spermatozoa. Modification of mitochondrial proteins expression after autophagy activation/inhibition may be indicating that a specialized form of autophagy named mitophagy may be regulating sperm function such as motility and viability and may be cooperating with apoptosis. PMID:27633131

  3. Microengineering methods for cell-based microarrays and high-throughput drug-screening applications

    International Nuclear Information System (INIS)

    Screening for effective therapeutic agents from millions of drug candidates is costly, time consuming, and often faces concerns due to the extensive use of animals. To improve cost effectiveness, and to minimize animal testing in pharmaceutical research, in vitro monolayer cell microarrays with multiwell plate assays have been developed. Integration of cell microarrays with microfluidic systems has facilitated automated and controlled component loading, significantly reducing the consumption of the candidate compounds and the target cells. Even though these methods significantly increased the throughput compared to conventional in vitro testing systems and in vivo animal models, the cost associated with these platforms remains prohibitively high. Besides, there is a need for three-dimensional (3D) cell-based drug-screening models which can mimic the in vivo microenvironment and the functionality of the native tissues. Here, we present the state-of-the-art microengineering approaches that can be used to develop 3D cell-based drug-screening assays. We highlight the 3D in vitro cell culture systems with live cell-based arrays, microfluidic cell culture systems, and their application to high-throughput drug screening. We conclude that among the emerging microengineering approaches, bioprinting holds great potential to provide repeatable 3D cell-based constructs with high temporal, spatial control and versatility.

  4. Experimental observations consistent with a surface tension model of gliding motility of Myxococcus xanthus.

    OpenAIRE

    Dworkin, M; Keller, K H; Weisberg, D.

    1983-01-01

    We have presented experimental evidence to support the model that gliding motility of Myxococcus xanthus is driven by surface tension. (i) Motility is inhibited by the addition of sufficient exogenous, nontoxic surfactants to swamp out the cells' own surfactant gradient. (ii) M. xanthus does not move polystyrene latex beads over its surface. (iii) Motility is prevented by elimination of an interfacial surface tension either by embedding the cells in soft agar or by placing them at an agar-aqu...

  5. High motility reduces grazing mortality of planktonic bacteria

    DEFF Research Database (Denmark)

    Matz, Carsten; Jurgens, K.

    2005-01-01

    We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... at high growth rates and under starvation with the following results: (i) for two out of three strains increased growth rate resulted in larger and slower bacterial cells, and (ii) starved cells became smaller but maintained their swimming speeds. Combined data sets for bacterial swimming speed and cell...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum...

  6. Digital microfluidic three-dimensional cell culture and chemical screening platform using alginate hydrogels.

    Science.gov (United States)

    George, Subin M; Moon, Hyejin

    2015-03-01

    Electro wetting-on-dielectric (EWOD) digital microfluidics (DMF) can be used to develop improved chemical screening platforms using 3-dimensional (3D) cell culture. Alginate hydrogels are one common method by which a 3D cell culture environment is created. This paper presents a study of alginate gelation on EWOD DMF and investigates designs to obtain uniform alginate hydrogels that can be repeatedly addressed by any desired liquids. A design which allows for gels to be retained in place during liquid delivery and removal without using any physical barriers or hydrophilic patterning of substrates is presented. A proof of concept screening platform is demonstrated by examining the effects of different concentrations of a test chemical on 3D cells in alginate hydrogels. In addition, the temporal effects of the various chemical concentrations on different hydrogel posts are demonstrated, thereby establishing the benefits of an EWOD DMF 3D cell culture and chemical screening platform using alginate hydrogels. PMID:25945142

  7. An industrial multi-crystalline EWT solar cell with screen printed metallization

    Energy Technology Data Exchange (ETDEWEB)

    Schoenecker, A.; De Moor, H.H.C.; Burgers, A.R.; Weeber, A.W.; Hoornstra, J.; Sinke, W.C. [ECN Renewable Energy, Solar and Wind, Petten (Netherlands); Michiels, P.P.; Steeman, R.A. [Shell Solar Energy, Helmond (Netherlands)

    1997-07-01

    The first results from the processing of an emitter wrap-through solar cell (EWT cell) based on 10x10 cm{sup 2} multicrystalline silicon solar cell technology with screen printing technique are shown. The processing bottlenecks such as laser cutting without material deterioration and the geometrical limitations due to screen printing techniques and emitter series resistance are addressed. The characterisation of the EWT solar cells clearly shows the expected higher photocurrent but fill factor and open circuit voltage need further improvements. Nevertheless it was possible to develop a stable processing scheme and cell design that allowed the processing of a number of EWT cells with reasonable efficiencies to make the first modules. Thus the advantages of a complete backside contacted module could be demonstrated by the first standard 36 cell EWT demonstration module. 8 figs., 6 refs.

  8. A molecular screening approach to identify and characterize inhibitors of glioblastoma stem cells.

    Science.gov (United States)

    Visnyei, Koppany; Onodera, Hideyuki; Damoiseaux, Robert; Saigusa, Kuniyasu; Petrosyan, Syuzanna; De Vries, David; Ferrari, Denise; Saxe, Jonathan; Panosyan, Eduard H; Masterman-Smith, Michael; Mottahedeh, Jack; Bradley, Kenneth A; Huang, Jing; Sabatti, Chiara; Nakano, Ichiro; Kornblum, Harley I

    2011-10-01

    Glioblastoma (GBM) is among the most lethal of all cancers. GBM consist of a heterogeneous population of tumor cells among which a tumor-initiating and treatment-resistant subpopulation, here termed GBM stem cells, have been identified as primary therapeutic targets. Here, we describe a high-throughput small molecule screening approach that enables the identification and characterization of chemical compounds that are effective against GBM stem cells. The paradigm uses a tissue culture model to enrich for GBM stem cells derived from human GBM resections and combines a phenotype-based screen with gene target-specific screens for compound identification. We used 31,624 small molecules from 7 chemical libraries that we characterized and ranked based on their effect on a panel of GBM stem cell-enriched cultures and their effect on the expression of a module of genes whose expression negatively correlates with clinical outcome: MELK, ASPM, TOP2A, and FOXM1b. Of the 11 compounds meeting criteria for exerting differential effects across cell types used, 4 compounds showed selectivity by inhibiting multiple GBM stem cells-enriched cultures compared with nonenriched cultures: emetine, n-arachidonoyl dopamine, n-oleoyldopamine (OLDA), and n-palmitoyl dopamine. ChemBridge compounds #5560509 and #5256360 inhibited the expression of the 4 mitotic module genes. OLDA, emetine, and compounds #5560509 and #5256360 were chosen for more detailed study and inhibited GBM stem cells in self-renewal assays in vitro and in a xenograft model in vivo. These studies show that our screening strategy provides potential candidates and a blueprint for lead compound identification in larger scale screens or screens involving other cancer types. PMID:21859839

  9. False Negative Cell-Free DNA Screening Result in a Newborn with Trisomy 13

    OpenAIRE

    Yang Cao; Nicole L. Hoppman; Sarah E Kerr; Sattler, Christopher A.; Borowski, Kristi S.; Wick, Myra J.; Edward Highsmith, W.; Umut Aypar

    2016-01-01

    Background. Noninvasive prenatal screening (NIPS) is revolutionizing prenatal screening as a result of its increased sensitivity, specificity. NIPS analyzes cell-free fetal DNA (cffDNA) circulating in maternal plasma to detect fetal chromosome abnormalities. However, cffDNA originates from apoptotic placental trophoblast; therefore cffDNA is not always representative of the fetus. Although the published data for NIPS testing states that the current technique ensures high sensitivity and speci...

  10. Sperm motility of externally fertilizing fish and amphibians.

    Science.gov (United States)

    Browne, R K; Kaurova, S A; Uteshev, V K; Shishova, N V; McGinnity, D; Figiel, C R; Mansour, N; Agney, D; Wu, M; Gakhova, E N; Dzyuba, B; Cosson, J

    2015-01-01

    We review the phylogeny, sperm competition, morphology, physiology, and fertilization environments of the sperm of externally fertilizing fish and amphibians. Increased sperm competition in both fish and anurans generally increases sperm numbers, sperm length, and energy reserves. The difference between the internal osmolarity and iconicity of sperm cells and those of the aquatic medium control the activation, longevity, and velocity of sperm motility. Hypo-osmolarity of the aquatic medium activates the motility of freshwater fish and amphibian sperm and hyperosmolarity activates the motility of marine fish sperm. The average longevity of the motility of marine fish sperm (~550 seconds) was significantly (P amphibian sperm in general and anurans reversion from internal to external fertilization. Our findings provide a greater understanding of the reproductive biology of externally fertilizing fish and amphibians, and a biological foundation for the further development of reproduction technologies for their sustainable management.

  11. Elenoside increases intestinal motility

    Institute of Scientific and Technical Information of China (English)

    E Navarro; SJ Alonso; R Navarro; J Trujillo; E Jorge

    2006-01-01

    AIM: To study the effects of elenoside, an arylnaphthalene lignan from Justicia hyssopifolia, on gastrointestinal motility in vivo and in vitro in rats.METHODS: Routine in vivo experimental assessments were catharsis index, water percentage of boluses,intestinal transit, and codeine antagonism. The groups included were vehicle control (propylene glycol-ethanolplant oil-tween 80), elenoside (i.p. 25 and 50 mg/kg),cisapride (i.p. 10 mg/kg), and codeine phosphate (intragastric route, 50 mg/kg). In vitro approaches used isolated rat intestinal tissues (duodenum, jejunum, and ileum). The effects of elenoside at concentrations of 3.2× 10-4, 6.4 × 10-4 and 1.2 × 10-3 mol/L, and cisapride at 10-6 mol/L were investigated.RESULTS: Elenoside in vivo produced an increase in the catharsis index and water percentage of boluses and in the percentage of distance traveled by a suspension of activated charcoal. Codeine phosphate antagonized the effect of 25 mg/kg of elenoside. In vitro, elenoside in duodenum, jejunum and ileum produced an initial decrease in the contraction force followed by an increase.Elenoside resulted in decreased intestinal frequency in duodenum, jejunum, and ileum. The in vitro and in vivo effects of elenoside were similar to those produced by cisapride.CONCLUSION: Elenoside is a lignan with an action similar to that of purgative and prokinetics drugs.Elenoside, could be an alternative to cisapride in treatment of gastrointestinal diseases as well as a preventive therapy for the undesirable gastrointestinal effects produced by opioids used for mild to moderate pain.

  12. Characterization of pro-inflammatory flagellin proteins produced by Lactobacillus ruminis and related motile Lactobacilli.

    Directory of Open Access Journals (Sweden)

    B Anne Neville

    Full Text Available Lactobacillus ruminis is one of at least twelve motile but poorly characterized species found in the genus Lactobacillus. Of these, only L. ruminis has been isolated from mammals, and this species may be considered as an autochthonous member of the gastrointestinal microbiota of humans, pigs and cows. Nine L. ruminis strains were investigated here to elucidate the biochemistry and genetics of Lactobacillus motility. Six strains isolated from humans were non-motile while three bovine isolates were motile. A complete set of flagellum biogenesis genes was annotated in the sequenced genomes of two strains, ATCC25644 (human isolate and ATCC27782 (bovine isolate, but only the latter strain produced flagella. Comparison of the L. ruminis and L. mali DSM20444(T motility loci showed that their genetic content and gene-order were broadly similar, although the L. mali motility locus was interrupted by an 11.8 Kb region encoding rhamnose utilization genes that is absent from the L. ruminis motility locus. Phylogenetic analysis of 39 motile bacteria indicated that Lactobacillus motility genes were most closely related to those of motile carnobacteria and enterococci. Transcriptome analysis revealed that motility genes were transcribed at a significantly higher level in motile L. ruminis ATCC27782 than in non-motile ATCC25644. Flagellin proteins were isolated from L. ruminis ATCC27782 and from three other Lactobacillus species, while recombinant flagellin of aflagellate L. ruminis ATCC25644 was expressed and purified from E. coli. These native and recombinant Lactobacillus flagellins, and also flagellate L. ruminis cells, triggered interleukin-8 production in cultured human intestinal epithelial cells in a manner suppressed by short interfering RNA directed against Toll-Like Receptor 5. This study provides genetic, transcriptomic, phylogenetic and immunological insights into the trait of flagellum-mediated motility in the lactobacilli.

  13. A High-Throughput Small Molecule Screen for C. elegans Linker Cell Death Inhibitors

    Science.gov (United States)

    Schwendeman, Andrew R.; Shaham, Shai

    2016-01-01

    Programmed cell death is a ubiquitous process in metazoan development. Apoptosis, one cell death form, has been studied extensively. However, mutations inactivating key mammalian apoptosis regulators do not block most developmental cell culling, suggesting that other cell death pathways are likely important. Recent work in the nematode Caenorhabditis elegans identified a non-apoptotic cell death form mediating the demise of the male-specific linker cell. This cell death process (LCD, linker cell-type death) is morphologically conserved, and its molecular effectors also mediate axon degeneration in mammals and Drosophila. To develop reagents to manipulate LCD, we established a simple high-throughput screening protocol for interrogating the effects of small molecules on C. elegans linker cell death in vivo. From 23,797 compounds assayed, 11 reproducibly block linker cell death onset. Of these, five induce animal lethality, and six promote a reversible developmental delay. These results provide proof-of principle validation of our screening protocol, demonstrate that developmental progression is required for linker cell death, and suggest that larger scale screens may identify LCD-specific small-molecule regulators that target the LCD execution machinery. PMID:27716809

  14. An open source based high content screening method for cell biology laboratories investigating cell spreading and adhesion.

    Directory of Open Access Journals (Sweden)

    Andre Schmandke

    Full Text Available BACKGROUND: Adhesion dependent mechanisms are increasingly recognized to be important for a wide range of biological processes, diseases and therapeutics. This has led to a rising demand of pharmaceutical modulators. However, most currently available adhesion assays are time consuming and/or lack sensitivity and reproducibility or depend on specialized and expensive equipment often only available at screening facilities. Thus, rapid and economical high-content screening approaches are urgently needed. RESULTS: We established a fully open source high-content screening method for identifying modulators of adhesion. We successfully used this method to detect small molecules that are able to influence cell adhesion and cell spreading of Swiss-3T3 fibroblasts in general and/or specifically counteract Nogo-A-Δ20-induced inhibition of adhesion and cell spreading. The tricyclic anti-depressant clomipramine hydrochloride was shown to not only inhibit Nogo-A-Δ20-induced cell spreading inhibition in 3T3 fibroblasts but also to promote growth and counteract neurite outgrowth inhibition in highly purified primary neurons isolated from rat cerebellum. CONCLUSIONS: We have developed and validated a high content screening approach that can be used in any ordinarily equipped cell biology laboratory employing exclusively freely available open-source software in order to find novel modulators of adhesion and cell spreading. The versatility and adjustability of the whole screening method will enable not only centers specialized in high-throughput screens but most importantly also labs not routinely employing screens in their daily work routine to investigate the effects of a wide range of different compounds or siRNAs on adhesion and adhesion-modulating molecules.

  15. Metabolite profiling of microfluidic cell culture conditions for droplet based screening

    DEFF Research Database (Denmark)

    2015-01-01

    , such as directed evolution of yeast, as cell metabolic state directly affects production yields from cell factories. Here, we analyze glucose, pyruvate, ethanol, and glycerol, central metabolites in yeast glucose dissimilation to establish culture formats for screening of respiring as well as fermenting yeast......We investigate the impact of droplet culture conditions on cell metabolic state by determining key metabolite concentrations in S. cerevisiae cultures in different microfluidic droplet culture formats. Control of culture conditions is critical for single cell/clone screening in droplets....... Metabolite profiling provides a more nuanced estimate of cell state compared to proliferation studies alone. We show that the choice of droplet incubation format impacts cell proliferation and metabolite production. The standard syringe incubation of droplets exhibited metabolite profiles similar to oxygen...

  16. Inhibition of Collagen Synthesis and Regulation of Cell Motility in Vascular Smooth Muscle Cells by Suppression of Connective Tissue growth Factor Expression Using RNA Interference

    Institute of Scientific and Technical Information of China (English)

    Xiao-Jing LIU; Huai-Qing CHEN

    2005-01-01

    @@ 1 Introduction Vascular smooth muscle cell (VSMC) hyperplasia plays an important role in both chronic and acute pathologies including atherosclerosis and restenosis. Recent studies have shown that connective tissue growth factor (CTGF) is a novel growth factor involved in the development and progression of atherosclerosis.

  17. Three-Dimensional Spheroid Cell Culture Model for Target Identification Utilizing High-Throughput RNAi Screens.

    Science.gov (United States)

    Iles, LaKesla R; Bartholomeusz, Geoffrey A

    2016-01-01

    The intrinsic limitations of 2D monolayer cell culture models have prompted the development of 3D cell culture model systems for in vitro studies. Multicellular tumor spheroid (MCTS) models closely simulate the pathophysiological milieu of solid tumors and are providing new insights into tumor biology as well as differentiation, tissue organization, and homeostasis. They are straightforward to apply in high-throughput screens and there is a great need for the development of reliable and robust 3D spheroid-based assays for high-throughput RNAi screening for target identification and cell signaling studies highlighting their potential in cancer research and treatment. In this chapter we describe a stringent standard operating procedure for the use of MCTS for high-throughput RNAi screens. PMID:27581289

  18. A microfluidic-based genetic screen to identify microbial virulence factors that inhibit dendritic cell migration

    OpenAIRE

    McLaughlin, Laura M.; Xu, Hui; Carden, Sarah E.; Fisher, Samantha; Reyes, Monique; Heilshorn, Sarah C.; Monack, Denise M.

    2014-01-01

    Microbial pathogens are able to modulate host cells and evade the immune system by multiple mechanisms. For example, Salmonella injects effector proteins into host cells and evades the host immune system in part by inhibiting dendritic cell (DC) migration. The identification of microbial factors that modulate normal host functions should lead to the development of new classes of therapeutics that target these pathways. Current screening methods to identify either host or pathogen genes involv...

  19. Isolation of Salmonella mutants resistant to the inhibitory effect of Salicylidene acylhydrazides on flagella-mediated motility.

    Science.gov (United States)

    Martinez-Argudo, Isabel; Veenendaal, Andreas K J; Liu, Xia; Roehrich, A Dorothea; Ronessen, Maria C; Franzoni, Giulia; van Rietschoten, Katerine N; Morimoto, Yusuke V; Saijo-Hamano, Yumiko; Avison, Matthew B; Studholme, David J; Namba, Keiichi; Minamino, Tohru; Blocker, Ariel J

    2013-01-01

    Salicylidene acylhydrazides identified as inhibitors of virulence-mediating type III secretion systems (T3SSs) potentially target their inner membrane export apparatus. They also lead to inhibition of flagellar T3SS-mediated swimming motility in Salmonella enterica serovar. Typhimurium. We show that INP0404 and INP0405 act by reducing the number of flagella/cell. These molecules still inhibit motility of a Salmonella ΔfliH-fliI-fliJ/flhB((P28T)) strain, which lacks three soluble components of the flagellar T3S apparatus, suggesting that they are not the target of this drug family. We implemented a genetic screen to search for the inhibitors' molecular target(s) using motility assays in the ΔfliH-fliI/flhB((P28T)) background. Both mutants identified were more motile than the background strain in the absence of the drugs, although HM18 was considerably more so. HM18 was more motile than its parent strain in the presence of both drugs while DI15 was only insensitive to INP0405. HM18 was hypermotile due to hyperflagellation, whereas DI15 was not hyperflagellated. HM18 was also resistant to a growth defect induced by high concentrations of the drugs. Whole-genome resequencing of HM18 indicated two alterations within protein coding regions, including one within atpB, which encodes the inner membrane a-subunit of the F(O)F(1)-ATP synthase. Reverse genetics indicated that the alteration in atpB was responsible for all of HM18's phenotypes. Genome sequencing of DI15 uncovered a single A562P mutation within a gene encoding the flagellar inner membrane protein FlhA, the direct role of which in mediating drug insensitivity could not be confirmed. We discuss the implications of these findings in terms of T3SS export apparatus function and drug target identification.

  20. Isolation of Salmonella mutants resistant to the inhibitory effect of Salicylidene acylhydrazides on flagella-mediated motility.

    Directory of Open Access Journals (Sweden)

    Isabel Martinez-Argudo

    Full Text Available Salicylidene acylhydrazides identified as inhibitors of virulence-mediating type III secretion systems (T3SSs potentially target their inner membrane export apparatus. They also lead to inhibition of flagellar T3SS-mediated swimming motility in Salmonella enterica serovar. Typhimurium. We show that INP0404 and INP0405 act by reducing the number of flagella/cell. These molecules still inhibit motility of a Salmonella ΔfliH-fliI-fliJ/flhB((P28T strain, which lacks three soluble components of the flagellar T3S apparatus, suggesting that they are not the target of this drug family. We implemented a genetic screen to search for the inhibitors' molecular target(s using motility assays in the ΔfliH-fliI/flhB((P28T background. Both mutants identified were more motile than the background strain in the absence of the drugs, although HM18 was considerably more so. HM18 was more motile than its parent strain in the presence of both drugs while DI15 was only insensitive to INP0405. HM18 was hypermotile due to hyperflagellation, whereas DI15 was not hyperflagellated. HM18 was also resistant to a growth defect induced by high concentrations of the drugs. Whole-genome resequencing of HM18 indicated two alterations within protein coding regions, including one within atpB, which encodes the inner membrane a-subunit of the F(OF(1-ATP synthase. Reverse genetics indicated that the alteration in atpB was responsible for all of HM18's phenotypes. Genome sequencing of DI15 uncovered a single A562P mutation within a gene encoding the flagellar inner membrane protein FlhA, the direct role of which in mediating drug insensitivity could not be confirmed. We discuss the implications of these findings in terms of T3SS export apparatus function and drug target identification.

  1. Inhibition of Collagen Synthesis and Regulation of Cell Motility in Vascular Smooth Muscle Cells by Suppression of Connective Tissue growth Factor Expression Using RNAInterference

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    1 IntroductionVascular smooth muscle cell (VSMC) hyperplasia plays an important role in both chronic and acute pathologies including atherosclerosis and restenosis. Recent studies have shown that connective tissue growth factor (CTGF) is a novel growth factor involved in the development and progression of atherosclerosis. However, previous data about the role of CTGF on the VSMC is conflicting. Hishikawa et al demonstrated that CTGF could act as a growth inhibitor in human VSMC; but some others' reports (Fa...

  2. Single-cell screening of photosynthetic growth and lactate production by cyanobacteria

    DEFF Research Database (Denmark)

    Hammar, Petter; Angermayr, S. Andreas; Sjostrom, Staffan L.;

    2015-01-01

    Background: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible.Results: We present a method for high-throughput, single-cell analy......Background: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible.Results: We present a method for high-throughput, single...... stalled cells.Conclusions: The workflow will facilitate metabolic engineering and directed evolution studies and will be useful in studies of cyanobacteria biochemistry and physiology....

  3. Normalizing for individual cell population context in the analysis of high-content cellular screens

    Directory of Open Access Journals (Sweden)

    Knapp Bettina

    2011-12-01

    Full Text Available Abstract Background High-content, high-throughput RNA interference (RNAi offers unprecedented possibilities to elucidate gene function and involvement in biological processes. Microscopy based screening allows phenotypic observations at the level of individual cells. It was recently shown that a cell's population context significantly influences results. However, standard analysis methods for cellular screens do not currently take individual cell data into account unless this is important for the phenotype of interest, i.e. when studying cell morphology. Results We present a method that normalizes and statistically scores microscopy based RNAi screens, exploiting individual cell information of hundreds of cells per knockdown. Each cell's individual population context is employed in normalization. We present results on two infection screens for hepatitis C and dengue virus, both showing considerable effects on observed phenotypes due to population context. In addition, we show on a non-virus screen that these effects can be found also in RNAi data in the absence of any virus. Using our approach to normalize against these effects we achieve improved performance in comparison to an analysis without this normalization and hit scoring strategy. Furthermore, our approach results in the identification of considerably more significantly enriched pathways in hepatitis C virus replication than using a standard analysis approach. Conclusions Using a cell-based analysis and normalization for population context, we achieve improved sensitivity and specificity not only on a individual protein level, but especially also on a pathway level. This leads to the identification of new host dependency factors of the hepatitis C and dengue viruses and higher reproducibility of results.

  4. Convenient cell fusion assay for rapid screening for HIV entry inhibitors

    Science.gov (United States)

    Jiang, Shibo; Radigan, Lin; Zhang, Li

    2000-03-01

    Human immunodeficiency viruses (HIV)-induced cell fusion is a critical pathway of HIV spread from infected cells to uninfected cells. A rapid and simple assay was established to measure HIV-induce cell fusion. This study is particularly useful to rapid screen for HIV inhibitors that block HIV cell-to-cell transmission. Present study demonstrated that coculture of HIV-infected cells with uninfected cells at 37 degree(s)C for 2 hours resulted in the highest cell fusion rate. Using this cell fusion assay, we have identified several potent HIV inhibitors targeted to the HIV gp41 core. These antiviral agents can be potentially developed as antiviral drugs for chemotherapy and prophylaxis of HIV infection and AIDS.

  5. Cells Cultured on Core-Shell Photonic Crystal Barcodes for Drug Screening.

    Science.gov (United States)

    Fu, Fanfan; Shang, Luoran; Zheng, Fuyin; Chen, Zhuoyue; Wang, Huan; Wang, Jie; Gu, Zhongze; Zhao, Yuanjin

    2016-06-01

    The development of effective drug screening platforms is an important task for biomedical engineering. Here, a novel methacrylated gelatin (GelMA) hydrogel-encapsulated core-shell photonic crystal (PhC) barcode particle was developed for three-dimensional cell aggregation culture and drug screening. The GelMA shells of the barcode particles enable creation of a three-dimensional extracellular matrix (ECM) microenvironment for cell adhesion and growth, while the PhC cores of the barcode particles provide stable diffraction peaks that can encode different cell spheroids during culture and distinguish their biological response during drug testing. The applicability of this cell spheroids-on-barcodes platform was investigated by testing the cytotoxic effect of tegafur (TF), a prodrug of 5-fluorouracil (5-FU), on barcode particle-loaded liver HepG2 and HCT-116 colonic tumor cell spheroids. The cytotoxicity of TF against the HCT-116 tumor cell spheroids was enhanced in systems using cocultures of HepG2 and NIH-3T3 cells, indicating the effectiveness of this multiple cell spheroids-on-barcodes platform for drug screening. PMID:27214156

  6. Quantitative mammalian cell mutagenesis and mutagen screening: study with CHO cells

    International Nuclear Information System (INIS)

    The CHO/HGPRT system has been developed and defined for quantifying mutation induced by various physical and chemical agents at the hypoxanthine-guanine phosphoribosyl transferase (HGPRT) locus in Chinese hamster ovary (CHO) cells. In all direct-acting chemical mutagens studied, mutation induction increases linearly as a function of the concentration, with no apparent threshold. Some chemicals induce mutation at non-cytotoxic concentrations. The mutagenicity of ethyl methanesulfonate has been quantified as a function of exposure concentration x treatment time. The sensitive and quantitative nature of the system enables studies of the structure-activity (mutagenicity) relationships of various classes of chemicals, including alkylating agents, heterocyclic nitrogen mustards, and platinum compounds. When rat liver S9-mediated metabolic activation is present, procarcinogens such as benzo(a)pyrene, 2-acetylaminofluorene, and dimethylnitrosamine are mutagenic, whereas their noncarcinogenic structural analogues pyrene, fluorene, and dimethylamine are not. The system has been shown to be useful in determining the interactive effects between physical and chemical agents, and in screening for mutagenicity of fractionated organic mixtures and industrial chemicals in both liquid and gaseous state. For the system to be used successfully in routine screening, further studies should be directed toward the development of a metabolic activation system suitable for a broad spectrum of chemicals, a sensitive and reliable statistical method, and an experimental design to determine compounds with low mutagenicity. The system has been expanded for determination of mutagen-induced chromosome aberration, sister-chromatid exchange, and micronucleus formation in addition to gene mutation and cytotoxicity; it can also be used to study inhibition of DNA synthesis

  7. Motility-driven glass and jamming transitions in biological tissues

    CERN Document Server

    Bi, Dapeng; Marchetti, M Cristina; Manning, M Lisa

    2015-01-01

    Cell motion inside dense tissues governs many biological processes, including embryonic development and cancer metastasis, and recent experiments suggest that these tissues exhibit collective glassy behavior. To make quantitative predictions about glass transitions in tissues, we study a self-propelled Voronoi (SPV) model that simultaneously captures polarized cell motility and multi-body cell-cell interactions in a confluent tissue, where there are no gaps between cells. We demonstrate that the model exhibits a jamming transition from a solid-like state to a fluid-like state that is controlled by three parameters: the single-cell motile speed, the persistence time of single-cell tracks, and a target shape index that characterizes the competition between cell-cell adhesion and cortical tension. In contrast to traditional particulate glasses, we are able to identify an experimentally accessible structural order parameter that specifies the entire jamming surface as a function of model parameters. We demonstrat...

  8. Cytotoxicity screening of essential oils in cancer cell lines

    Directory of Open Access Journals (Sweden)

    Pollyanna Francielli de Oliveira

    2015-04-01

    Full Text Available Abstract This study evaluated the cytotoxicity activity of the essential oils of Tagetes erecta L., Asteraceae (TE-OE, Tetradenia riparia (Hochst. Codd, Lamiaceae (TR-OE, Bidens sulphurea (Cav. Sch. Bip., Asteraceae (BS-OE, and Foeniculum vulgare Mill., Apiaceae (FV-OE, traditionally used in folk medicine, against the tumor cell lines murine melanoma (B16F10, human colon carcinoma (HT29, human breast adenocarcinoma (MCF-7, human cervical adenocarcinoma (HeLa, human hepatocellular liver carcinoma (HepG2, and human glioblastoma (MO59J, U343, and U251. Normal hamster lung fibroblasts (V79 cells were included as control. The cells were treated with essential oil concentrations ranging from 3.12 to 400 µg/ml for 24 h. The cytotoxic activity was evaluated using the XTT assay; results were expressed as IC50, and the selectivity index was calculated. The results were compared with those achieved for classic chemotherapeutic agents. TE-OE was the most promising among the evaluated oils: it afforded the lowest IC50 values for B16F10 cells (7.47 ± 1.08 µg/ml and HT29 cells (6.93 ± 0.77 µg/ml, as well as selectivity indices of 2.61 and 2.81, respectively. The major BS-EO, FV-EO and TE-EO chemical constituents were identified by gas chromatography mass spectrometry as being (E-caryophyllene (10.5%, germacrene D (35.0% and 2,6-di-tert-butyl-4-methylphenol (43.0% (BS-EO; limonene (21.3% and (E-anethole (70.2% (FV-EO; limonene (10.4%, dihydrotagetone (11.8%, α-terpinolene (18.1% and (E-ocimenone (13.0% (TE-EO; and fenchone (6.1%, dronabinol (11.0%, aromadendrene oxide (14.7% and (E,E–farnesol (15.0% (TR-EO. 2,6-di-tert-butyl-4-methylphenol (43.0%, (E-anethole (70.2% and α-terpinolene (18.1%, respectively. These results suggest that TE-OE may be used to treat cancer without affecting normal cells.

  9. Single-cell screening of photosynthetic growth and lactate production by cyanobacteria

    NARCIS (Netherlands)

    P. Hammar; S.A. Angermayr; S.L. Sjostrom; J. van der Meer; K.J. Hellingwerf; E.P. Hudson; H.N. Joensson

    2015-01-01

    BACKGROUND: Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible. RESULTS: We present a method for high-throughput, single-cell analysi

  10. Beyond White Blood Cell Monitoring : Screening in the Initial Phase of Clozapine Therapy

    NARCIS (Netherlands)

    Cohen, Dan; Bogers, Jan P. A. M.; van Dijk, Daniel; Bakker, Bert; Schulte, Peter F. J.

    2012-01-01

    Objective: Clozapine is the preferred option for treatment-resistant schizophrenia. However, since 1975, clozapine has been known to cause agranulocytosis. In the clozapine screening guidelines, white blood cell count is mandatory. In the past 20 years, after its reintroduction, 3 other serious side

  11. Quality Indicator Development for Positive Screen Follow-up for Sickle Cell Disease and Trait.

    Science.gov (United States)

    Faro, Elissa Z; Wang, C Jason; Oyeku, Suzette O

    2016-07-01

    Extensive variation exists in the follow-up of positive screens for sickle cell disease. Limited quality indicators exist to measure if the public health goals of screening-early initiation of treatment and enrollment to care-are being achieved. This manuscript focuses on the development of quality indicators related to the follow-up care for individuals identified with sickle cell disease and trait through screening processes. The authors used a modified Delphi method to develop the indicators. The process included a comprehensive literature review with rating of the evidence followed by ratings of draft indicators by an expert panel held in September 2012. The expert panel was nominated by leaders of various professional societies, the Health Resources and Services Administration, and the National Heart, Lung, and Blood Institute and met face to face to discuss and rate each indicator. The panel recommended nine quality indicators focused on key aspects of follow-up care for individuals with positive screens for sickle cell disease and trait. Public health programs and healthcare institutions can use these indicators to assess the quality of follow-up care and provide a basis for improvement efforts to ensure appropriate family education, early initiation of treatment, and appropriate referral to care for individuals identified with sickle cell disease and trait. PMID:27320465

  12. Tetrandrine identified in a small molecule screen to activate mesenchymal stem cells for enhanced immunomodulation.

    Science.gov (United States)

    Yang, Zijiang; Concannon, John; Ng, Kelvin S; Seyb, Kathleen; Mortensen, Luke J; Ranganath, Sudhir; Gu, Fangqi; Levy, Oren; Tong, Zhixiang; Martyn, Keir; Zhao, Weian; Lin, Charles P; Glicksman, Marcie A; Karp, Jeffrey M

    2016-07-26

    Pre-treatment or priming of mesenchymal stem cells (MSC) prior to transplantation can significantly augment the immunosuppressive effect of MSC-based therapies. In this study, we screened a library of 1402 FDA-approved bioactive compounds to prime MSC. We identified tetrandrine as a potential hit that activates the secretion of prostaglandin E2 (PGE2), a potent immunosuppressive agent, by MSC. Tetrandrine increased MSC PGE2 secretion through the NF-κB/COX-2 signaling pathway. When co-cultured with mouse macrophages (RAW264.7), tetrandrine-primed MSC attenuated the level of TNF-α secreted by RAW264.7. Furthermore, systemic transplantation of primed MSC into a mouse ear skin inflammation model significantly reduced the level of TNF-α in the inflamed ear, compared to unprimed cells. Screening of small molecules to pre-condition cells prior to transplantation represents a promising strategy to boost the therapeutic potential of cell therapy.

  13. High content screening for G protein-coupled receptors using cell-based protein translocation assays

    DEFF Research Database (Denmark)

    Grånäs, Charlotta; Lundholt, Betina Kerstin; Heydorn, Arne;

    2005-01-01

    the capability to probe GPCR function at the cellular level with better resolution than has previously been possible, and offer practical strategies for more definitive selectivity evaluation and counter-screening in the early stages of drug discovery. The potential of cell-based translocation assays for GPCR...... will continue to be valuable discovery tools, the most exciting developments in the field involve cell-based assays for GPCR function. Some cell-based discovery strategies, such as the use of beta-arrestin as a surrogate marker for GPCR function, have already been reduced to practice, and have been used...... as valuable discovery tools for several years. The application of high content cell-based screening to GPCR discovery has opened up additional possibilities, such as direct tracking of GPCRs, G proteins and other signaling pathway components using intracellular translocation assays. These assays provide...

  14. Small intestine motility development in newborn mammals.

    Science.gov (United States)

    Woliński, Jarosław; Słupecka-Ziemilska, Monika; Boryczka, Maria; Grzesiak, Paulina; Kwiatkowski, Jakub; Kotarba, Grzegorz

    2016-01-01

    Since the beginning of the 20th century, researchers have been working to improve the understanding of gastrointestinal motility. The first major discovery was the observation of a migrating myoelectric complex that turned out to be a universal occurrence among vertebrates. Further inquires resulted in a detailed description of its development during different stages of ontogeny. Some time before that, a cornerstone had been laid for a breakthrough that would come years later. That cornerstone came in the form of interstitial cells of Cajal whose true role could not be discerned until the discovery of a CD117 receptor - their main marker. With the ability to precisely mark interstitial cells of Cajal, a wave of subsequent new experiments and observations connected them to the occurrence of slow waves and allowed an understanding of the mechanism responsible for their generation. Some of these findings suggested that Cajal cells might have a role in the development of several motility disorders thus opening an avenue of research that requires the usage of both traditional and advanced diagnostic methods.

  15. Epilepsy-induced motility of differentiated neurons.

    Science.gov (United States)

    Chai, Xuejun; Münzner, Gert; Zhao, Shanting; Tinnes, Stefanie; Kowalski, Janina; Häussler, Ute; Young, Christina; Haas, Carola A; Frotscher, Michael

    2014-08-01

    Neuronal ectopia, such as granule cell dispersion (GCD) in temporal lobe epilepsy (TLE), has been assumed to result from a migration defect during development. Indeed, recent studies reported that aberrant migration of neonatal-generated dentate granule cells (GCs) increased the risk to develop epilepsy later in life. On the contrary, in the present study, we show that fully differentiated GCs become motile following the induction of epileptiform activity, resulting in GCD. Hippocampal slice cultures from transgenic mice expressing green fluorescent protein in differentiated, but not in newly generated GCs, were incubated with the glutamate receptor agonist kainate (KA), which induced GC burst activity and GCD. Using real-time microscopy, we observed that KA-exposed, differentiated GCs translocated their cell bodies and changed their dendritic organization. As found in human TLE, KA application was associated with decreased expression of the extracellular matrix protein Reelin, particularly in hilar interneurons. Together these findings suggest that KA-induced motility of differentiated GCs contributes to the development of GCD and establish slice cultures as a model to study neuronal changes induced by epileptiform activity.

  16. A molecular screening approach to identify and characterize inhibitors of glioblastoma stem cells

    OpenAIRE

    Visnyei, Koppany; Onodera, Hideyuki; Damoiseaux, Robert; Saigusa, Kuniyasu; Petrosyan, Syuzanna; De Vries, David; Ferrari, Denise; Saxe, Jonathan; Panosyan, Eduard H.; Masterman-Smith, Michael; Mottahedeh, Jack; Bradley, Kenneth A.; Huang, Jing; Sabatti, Chiara; Nakano, Ichiro

    2011-01-01

    Glioblastoma multiforme (GBM) is amongst the most lethal of all cancers. GBM consist of a heterogeneous population of tumor cells amongst which a tumor initiating and treatment-resistant subpopulation, here termed GBM stem cells (GSC), have been identified as primary therapeutic targets. Here, we describe a high-throughput small molecule screening approach that enables the identification and characterization of chemical compounds that are effective against GSC. The paradigm uses a tissue cult...

  17. Development of a High-Throughput Functional Screen Using Nanowell-Assisted Cell Patterning.

    Science.gov (United States)

    Ozkumur, Ayca Yalcin; Goods, Brittany A; Love, J Christopher

    2015-09-01

    Living-cell-based screens can facilitate lead discovery of functional therapeutics of interest. A versatile and scalable method is reported that uses dense arrays of nanowells for imparting defined patterns on monolayers of cells. It is shown that this approach can coordinate a multi-component biological assay by designing and implementing a high-throughput, functional nanoliter-scale neutralization assay to identify neutralizing antibodies against HIV. PMID:26121321

  18. Stem cells: a model for screening, discovery and development of drugs

    OpenAIRE

    Kitambi SS; Chandrasekar G

    2011-01-01

    Satish Srinivas Kitambi1, Gayathri Chandrasekar21Department of Medical Biochemistry and Biophysics; 2Department of Biosciences, Karolinska Institutet, Stockholm, SwedenAbstract: The identification of normal and cancerous stem cells and the recent advances made in isolation and culture of stem cells have rapidly gained attention in the field of drug discovery and regenerative medicine. The prospect of performing screens aimed at proliferation, directed differentiation, and toxicity and efficac...

  19. Microengineering Methods for Cell Based Microarrays and High-Throughput Drug Screening Applications

    OpenAIRE

    Xu, Feng; Wu, Jinhui; Wang, Shuqi; Durmus, Naside Gozde; Gurkan, Umut Atakan; Demirci, Utkan

    2011-01-01

    Screening for effective therapeutic agents from millions of drug candidates is costly, time-consuming and often face ethical concerns due to extensive use of animals. To improve cost-effectiveness, and to minimize animal testing in pharmaceutical research, in vitro monolayer cell microarrays with multiwell plate assays have been developed. Integration of cell microarrays with microfluidic systems have facilitated automated and controlled component loading, significantly reducing the consumpti...

  20. False Negative Cell-Free DNA Screening Result in a Newborn with Trisomy 13

    Directory of Open Access Journals (Sweden)

    Yang Cao

    2016-01-01

    Full Text Available Background. Noninvasive prenatal screening (NIPS is revolutionizing prenatal screening as a result of its increased sensitivity, specificity. NIPS analyzes cell-free fetal DNA (cffDNA circulating in maternal plasma to detect fetal chromosome abnormalities. However, cffDNA originates from apoptotic placental trophoblast; therefore cffDNA is not always representative of the fetus. Although the published data for NIPS testing states that the current technique ensures high sensitivity and specificity for aneuploidy detection, false positives are possible due to isolated placental mosaicism, vanishing twin or cotwin demise, and maternal chromosome abnormalities or malignancy. Results. We report a case of false negative cell-free DNA (cfDNA screening due to fetoplacental mosaicism. An infant male with negative cfDNA screening result was born with multiple congenital abnormalities. Postnatal chromosome and FISH studies on a blood specimen revealed trisomy 13 in 20/20 metaphases and 100% interphase nuclei, respectively. FISH analysis on tissues collected after delivery revealed extraembryonic mosaicism. Conclusions. Extraembryonic tissue mosaicism is likely responsible for the false negative cfDNA screening result. This case illustrates that a negative result does not rule out the possibility of a fetus affected with a trisomy, as cffDNA is derived from the placenta and therefore may not accurately represent the fetal genetic information.

  1. False Negative Cell-Free DNA Screening Result in a Newborn with Trisomy 13

    Science.gov (United States)

    Cao, Yang; Hoppman, Nicole L.; Kerr, Sarah E.; Sattler, Christopher A.; Borowski, Kristi S.; Wick, Myra J.; Highsmith, W. Edward; Aypar, Umut

    2016-01-01

    Background. Noninvasive prenatal screening (NIPS) is revolutionizing prenatal screening as a result of its increased sensitivity, specificity. NIPS analyzes cell-free fetal DNA (cffDNA) circulating in maternal plasma to detect fetal chromosome abnormalities. However, cffDNA originates from apoptotic placental trophoblast; therefore cffDNA is not always representative of the fetus. Although the published data for NIPS testing states that the current technique ensures high sensitivity and specificity for aneuploidy detection, false positives are possible due to isolated placental mosaicism, vanishing twin or cotwin demise, and maternal chromosome abnormalities or malignancy. Results. We report a case of false negative cell-free DNA (cfDNA) screening due to fetoplacental mosaicism. An infant male with negative cfDNA screening result was born with multiple congenital abnormalities. Postnatal chromosome and FISH studies on a blood specimen revealed trisomy 13 in 20/20 metaphases and 100% interphase nuclei, respectively. FISH analysis on tissues collected after delivery revealed extraembryonic mosaicism. Conclusions. Extraembryonic tissue mosaicism is likely responsible for the false negative cfDNA screening result. This case illustrates that a negative result does not rule out the possibility of a fetus affected with a trisomy, as cffDNA is derived from the placenta and therefore may not accurately represent the fetal genetic information. PMID:26998368

  2. Generation of a predictive melphalan resistance index by drug screen of B-cell cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Martin Boegsted

    Full Text Available BACKGROUND: Recent reports indicate that in vitro drug screens combined with gene expression profiles (GEP of cancer cell lines may generate informative signatures predicting the clinical outcome of chemotherapy. In multiple myeloma (MM a range of new drugs have been introduced and now challenge conventional therapy including high dose melphalan. Consequently, the generation of predictive signatures for response to melphalan may have a clinical impact. The hypothesis is that melphalan screens and GEPs of B-cell cancer cell lines combined with multivariate statistics may provide predictive clinical information. MATERIALS AND METHODS: Microarray based GEPs and a melphalan growth inhibition screen of 59 cancer cell lines were downloaded from the National Cancer Institute database. Equivalent data were generated for 18 B-cell cancer cell lines. Linear discriminant analyses (LDA, sparse partial least squares (SPLS and pairwise comparisons of cell line data were used to build resistance signatures from both cell line panels. A melphalan resistance index was defined and estimated for each MM patient in a publicly available clinical data set and evaluated retrospectively by Cox proportional hazards and Kaplan-Meier survival analysis. PRINCIPAL FINDINGS: Both cell line panels performed well with respect to internal validation of the SPLS approach but only the B-cell panel was able to predict a significantly higher risk of relapse and death with increasing resistance index in the clinical data sets. The most sensitive and resistant cell lines, MOLP-2 and RPMI-8226 LR5, respectively, had high leverage, which suggests their differentially expressed genes to possess important predictive value. CONCLUSION: The present study presents a melphalan resistance index generated by analysis of a B-cell panel of cancer cell lines. However, the resistance index needs to be functionally validated and correlated to known MM biomarkers in independent data sets in order to

  3. DNA-electrophoresis of single cells - a method to screen for irradiated foodstuffs

    International Nuclear Information System (INIS)

    Microelectrophoresis of single cells can be used to detect γ-irradiation over a wide dose range and for a variety of products. It is a simple and rapid test for DNA damages and can be used for screening. The method was tested on cell suspensions of bone marrow and muscle cells from frozen chicken legs, chicken heart, turkey liver, beef and pork irradiated with doses up to 3 kGy. Cell suspensions were prepared by incubation of tissues in EDTA-SDS-buffer at pH 8. Single cell electrophoresis was performed in 0.75% agarose gel. DNA was visualised by silver staining. In unirradiated samples no or only a small amount of DNA penetrated the cell membranes. Cells of irradiated samples appeared like a ''comet'' due to to migration of DNA-fragments out of cell. (orig.)

  4. Characterization of mortality in children with sickle cell disease diagnosed through the Newborn Screening Program

    Directory of Open Access Journals (Sweden)

    Alessandra P. Sabarense

    2015-06-01

    Full Text Available OBJECTIVE: To characterize the deaths of 193 children with sickle cell disease screened by a neonatal program from 1998 to 2012 and contrast the initial years with the final years. METHODS: Deaths were identified by active surveillance of children absent to scheduled appointments in Blood Bank Clinical Centers (Hemominas. Clinical and epidemiological data came from death certificates, neonatal screening database, medical records, and family interviews. RESULTS: Between 1998 and 2012, 3,617,919 children were screened and 2,591 had sickle cell disease (1:1,400. There were 193 deaths (7.4%: 153 with SS/Sß0-talassemia, 34 SC and 6 Sß+thalassemia; 76.7% were younger than five years; 78% died in the hospital and 21% at home or in transit. The main causes of death were infection (45%, indeterminate (28%, and acute splenic sequestration (14%. In 46% of death certificates, the term "sickle cell" was not recorded. Seven-year death rate for children born between 1998 and 2005 was 5.43% versus 5.12% for those born between 2005 and 2012 (p = 0.72. Medical care was provided to 75% of children; 24% were unassisted. Medical care was provided within 6 hours of symptom onset in only half of the interviewed cases. In 40.5% of cases, death occurred within the first 24 hours. Low family income was recorded in 90% of cases, and illiteracy in 5%. CONCLUSIONS: Although comprehensive and effective, neonatal screening for sickle cell disease was not sufficient to significantly reduce mortality in a newborn screening program. Economic and social development and increase of the knowledge on sickle cell disease among health professionals and family are needed to overcome excessive mortality.

  5. Investigation of the screen printed contacts of silicon solar cells using Transmission Line Model

    Directory of Open Access Journals (Sweden)

    P. Panek

    2010-07-01

    Full Text Available Purpose: The aim of the paper is to analyze how to improve the quality of the screen printed contacts of silicon solar cells. This means forming front side grid in order to decrease contact resistance.Design/methodology/approach: The topography of screen printed contacts were investigated using ZEISS SUPRA 25 scanning electron microscope (SEM with an energy dispersive X-ray (EDS spectrometer for microchemical analysis. Front collection grid was created using two types of Ag pastes.The Transmission Line Model (TLM patterns were fabricated by screen printing method on p – type Czochralski silicon Cz-Si wafer with n+ emitter without texture and with a titanium oxide (TiOx layer as an antireflection coating (ARC. Electrical properties of contacts were investigated using TLM.Findings: This work presents a conventional analysis of a screen printing process for contact formation in the crystalline silicon solar cells. The seed layer was created using silver pasts by the screen printed metallization. These contact structures were investigated using SEM to gain a better understanding of the obtained electrical parameters.Research limitations/implications: The contact resistance of the screen-printed metallization depends not only on the kind of applied paste and firing conditions, but is also strongly influenced by the surface morphology of the silicon substrate.Practical implications: Contact formation is an important production step to be optimized in the development of high efficiency solar cells.Originality/value: The effect of co-firing different pasts (especially a past, which was prepared using silver nano-powder on electrical properties of silicon wafers.

  6. Inhibition of SIRT2 Potentiates the Anti-motility Activity of Taxanes: Implications for Antineoplastic Combination Therapies12

    OpenAIRE

    Bonezzi, Katiuscia; Belotti, Dorina; North, Brian J.; Ghilardi, Carmen; Borsotti, Patrizia; Resovi, Andrea; Ubezio, Paolo; Riva, Antonella; Giavazzi, Raffaella; Verdin, Eric; Taraboletti, Giulia

    2012-01-01

    Taxanes are potent inhibitors of cell motility, a property implicated in their antiangiogenic and antimetastatic activity and unrelated to their antiproliferative effect. The molecular mechanism of this anti-motility activity is poorly understood. In this study, we found that paclitaxel induced tubulin acetylation in endothelial and tumor cells, at concentrations that affected cell motility but not proliferation (10-8 to 10-9 M, for 4 hours). Induction of tubulin acetylation correlated with i...

  7. Leishmania chagasi T-cell antigens identified through a double library screen.

    Science.gov (United States)

    Martins, Daniella R A; Jeronimo, Selma M B; Donelson, John E; Wilson, Mary E

    2006-12-01

    Control of human visceral leishmaniasis in regions where it is endemic is hampered in part by limited accessibility to medical care and emerging drug resistance. There is no available protective vaccine. Leishmania spp. protozoa express multiple antigens recognized by the vertebrate immune system. Since there is not one immunodominant epitope recognized by most hosts, strategies must be developed to optimize selection of antigens for prevention and immunodiagnosis. For this reason, we generated a cDNA library from the intracellular amastigote form of Leishmania chagasi, the cause of South American visceral leishmaniasis. We employed a two-step expression screen of the library to systematically identify T-cell antigens and T-dependent B-cell antigens. The first step was aimed at identifying the largest possible number of clones producing an epitope-containing polypeptide by screening with a pool of sera from Brazilians with documented visceral leishmaniasis. After removal of clones encoding heat shock proteins, positive clones underwent a second-step screen for their ability to cause proliferation and gamma interferon responses in T cells from immune mice. Six unique clones were selected from the second screen for further analysis. The corresponding antigens were derived from glutamine synthetase, a transitional endoplasmic reticulum ATPase, elongation factor 1gamma, kinesin K39, repetitive protein A2, and a hypothetical conserved protein. Humans naturally infected with L. chagasi mounted both cellular and antibody responses to these proteins. Preparations containing multiple antigens may be optimal for immunodiagnosis and protective vaccines. PMID:17000724

  8. Cancer cell spheroids for screening of chemotherapeutics and drug-delivery systems.

    Science.gov (United States)

    Patel, Niravkumar R; Aryasomayajula, Bhawani; Abouzeid, Abraham H; Torchilin, Vladimir P

    2015-01-01

    Over the last few decades, the most popular platform to perform high-throughput screening for viable anti-neoplastic compounds has been monolayer cell culture. However, cells in monolayer culture lose many of their in vivo characteristics. As a result, this platform provides a limited predictive value in determining the clinical outcome of the compounds of interest. Using a technique known as 3D spheroid culture, may be the answer to this conundrum. Spheroids have been shown to mimic the tissue-like properties of tumors necessary for the proper evaluation of compounds. In this review, production of cancer cell spheroids, utilization of these spheroids in understanding various therapeutic mechanisms and the potential for their use in high-throughput screening of drugs and drug-delivery systems are discussed in detail. PMID:25996047

  9. Development of a screening approach for exploring cell factory potential through metabolic flux analysis and physiology

    DEFF Research Database (Denmark)

    Knudsen, Peter Boldsen; Nielsen, Kristian Fog; Thykær, Jette

    2012-01-01

    of the recombinant strains in order to evaluate their potential as fungal cell factories and for guiding further metabolic engineering strategies. To meet the demand for a fast and reliable method for physiological characterisation of fungal strains, a screening approach using a micro titer format was developed......The recent developments within the field of metabolic engineering have significantly increased the speed by which fungal recombinant strains are being constructed, pushing focus towards physiological characterisation and analysis. This raises demand for a tool for diligent analysis...... in the strains of interest during exponential growth. The novelty of this screening approach, is that potential cell factories are selected based on their metabolic capacity for producing various products on interest and these cell factories may in turn be characterised based on their flux distributions. As part...

  10. Electrochemical estrogen screen method based on the electrochemical behavior of MCF-7 cells.

    Science.gov (United States)

    Li, Jinlian; Song, Jia; Bi, Sheng; Zhou, Shi; Cui, Jiwen; Liu, Jiguang; Wu, Dongmei

    2016-08-01

    It was an urgent task to develop quick, cheap and accurate estrogen screen method for evaluating the estrogen effect of the booming chemicals. In this study, the voltammetric behavior between the estrogen-free and normal fragmented MCF-7 cell suspensions were compared, and the electrochemical signal (about 0.68V attributed by xanthine and guanine) of the estrogen-free fragmented MCF-7 cell suspension was obviously lower than that of the normal one. The electrochemistry detection of ex-secretion purines showed that the ability of ex-secretion purines of cells sharp decreased due to the removing of endogenous estrogen. The results indicated that the electrochemical signal of MCF-7 cells was related to the level of intracellular estrogen. When the level of intracellular estrogen was down-regulated, the concentrations of the xanthine and hypoxanthine decreased, which led to the electrochemical signal of MCF-7 cells fall. Based on the electrochemical signal, the electrochemical estrogen screen method was established. The estrogen effect of estradiol, nonylphenol and bisphenol A was evaluated with the electrochemical method, and the result was accordant with that of MTT assay. The electrochemical estrogen screen method was simple, quickly, cheap, objective, and it exploits a new way for the evaluation of estrogenic effects of chemicals. PMID:27108272

  11. Screening system of blocking agents of the receptor for advanced glycation endproducts in cells using fluorescence.

    Science.gov (United States)

    Jung, Dong Ho; Kim, Young Sook; Kim, Jin Sook

    2012-01-01

    Activation of the receptor for advanced glycation endproducts (RAGE) triggers cellular responses implicated in the pathogenesis of diabetic complications; blockade of RAGE has been shown to inhibit the development of diabetic complications. To develop a screening system to identify novel disruptors of advanced glycation endproducts (AGE)-RAGE binding, we used an AGE-RAGE binding system in RAGE-overexpressing cells; test compounds were screened using this system. To construct human RAGE-overexpressing cells, mouse mesangial cells (MMCs) were stably transfected with the pcDNA-human RAGE (hRAGE) vector and selected under 1 mg/mL gentamicin (G418). RAGE expression in hRAGE-overexpressing MMCs was analyzed by Western blotting with specific RAGE antibody. To identify novel disruptors of AGE-RAGE binding, 50 single compounds and AGE-bovine serum albumin (BSA)-Alexa 488 (AGE-BSA labeled with Alexa 488) were treated to the hRAGE-overexpressing MMCs. Nonbinding AGE-BSA-Alexa 488 was washed and fluorescence measured by microtiter plate reader (excitation wavelength, 485 nm; emission wavelength, 528 nm). In hRAGE-overexpressing cells, only treatment with AGE-BSA-Alexa 488 significantly increased fluorescence intensity in a dose-dependent manner. Of 50 compounds tested, genistein disrupted AGE-RAGE binding in a dose-dependent manner. This AGE-RAGE binding system using AGE-BSA-Alexa 488 in hRAGE-overexpressing cells was suitable for screening of agents that disrupt AGE-hRAGE binding.

  12. A Small-Molecule Screen for Enhanced Homing of Systemically Infused Cells

    Directory of Open Access Journals (Sweden)

    Oren Levy

    2015-03-01

    Full Text Available Poor homing of systemically infused cells to disease sites may limit the success of exogenous cell-based therapy. In this study, we screened 9,000 signal-transduction modulators to identify hits that increase mesenchymal stromal cell (MSC surface expression of homing ligands that bind to intercellular adhesion molecule 1 (ICAM-1, such as CD11a. Pretreatment of MSCs with Ro-31-8425, an identified hit from this screen, increased MSC firm adhesion to an ICAM-1-coated substrate in vitro and enabled targeted delivery of systemically administered MSCs to inflamed sites in vivo in a CD11a- (and other ICAM-1-binding domains-dependent manner. This resulted in a heightened anti-inflammatory response. This represents a new strategy for engineering cell homing to enhance therapeutic efficacy and validates CD11a and ICAM-1 as potential targets. Altogether, this multi-step screening process may significantly improve clinical outcomes of cell-based therapies.

  13. MiRNA mimic screen for improved expression of functional neurotensin receptor from HEK293 cells.

    Science.gov (United States)

    Xiao, Su; Chen, Yu-Chi; Betenbaugh, Michael J; Martin, Scott E; Shiloach, Joseph

    2015-08-01

    Obtaining adequate quantities of functional mammalian membrane proteins has been a bottleneck in their structural and functional studies because the expression of these proteins from mammalian cells is relatively low. To explore the possibility of enhancing expression of these proteins using miRNA, a stable T-REx-293 cell line expressing the neurotensin receptor type 1 (NTSR1), a hard-to-express G protein-coupled receptor (GPCR), was constructed. The cell line was then subjected to human miRNA mimic library screening. In parallel, an HEK293 cell line expressing luciferase was also screened with the same human miRNA mimic library. Five microRNA mimics: hsa-miR-22-5p, hsa-miR-18a-5p, hsa-miR-22-3p, hsa-miR-429, and hsa-miR-2110were identified from both screens. They led to 48% increase in the expression of functional NTSR1 and to 239% increase of luciferase expression. These miRNAs were also effective in enhancing the expression of secretedglypican-3 hFc-fusion protein from HEK293 cells.The results indicate that these molecules may have a wide role in enhancing the production of proteins with biomedical interest.

  14. A microfluidic-based genetic screen to identify microbial virulence factors that inhibit dendritic cell migration.

    Science.gov (United States)

    McLaughlin, Laura M; Xu, Hui; Carden, Sarah E; Fisher, Samantha; Reyes, Monique; Heilshorn, Sarah C; Monack, Denise M

    2014-04-01

    Microbial pathogens are able to modulate host cells and evade the immune system by multiple mechanisms. For example, Salmonella injects effector proteins into host cells and evades the host immune system in part by inhibiting dendritic cell (DC) migration. The identification of microbial factors that modulate normal host functions should lead to the development of new classes of therapeutics that target these pathways. Current screening methods to identify either host or pathogen genes involved in modulating migration towards a chemical signal are limited because they do not employ stable, precisely controlled chemical gradients. Here, we develop a positive selection microfluidic-based genetic screen that allows us to identify Salmonella virulence factors that manipulate DC migration within stable, linear chemokine gradients. Our screen identified 7 Salmonella effectors (SseF, SifA, SspH2, SlrP, PipB2, SpiC and SseI) that inhibit DC chemotaxis toward CCL19. This method is widely applicable for identifying novel microbial factors that influence normal host cell chemotaxis as well as revealing new mammalian genes involved in directed cell migration. PMID:24599496

  15. Electrochemical estrogen screen method based on the electrochemical behavior of MCF-7 cells.

    Science.gov (United States)

    Li, Jinlian; Song, Jia; Bi, Sheng; Zhou, Shi; Cui, Jiwen; Liu, Jiguang; Wu, Dongmei

    2016-08-01

    It was an urgent task to develop quick, cheap and accurate estrogen screen method for evaluating the estrogen effect of the booming chemicals. In this study, the voltammetric behavior between the estrogen-free and normal fragmented MCF-7 cell suspensions were compared, and the electrochemical signal (about 0.68V attributed by xanthine and guanine) of the estrogen-free fragmented MCF-7 cell suspension was obviously lower than that of the normal one. The electrochemistry detection of ex-secretion purines showed that the ability of ex-secretion purines of cells sharp decreased due to the removing of endogenous estrogen. The results indicated that the electrochemical signal of MCF-7 cells was related to the level of intracellular estrogen. When the level of intracellular estrogen was down-regulated, the concentrations of the xanthine and hypoxanthine decreased, which led to the electrochemical signal of MCF-7 cells fall. Based on the electrochemical signal, the electrochemical estrogen screen method was established. The estrogen effect of estradiol, nonylphenol and bisphenol A was evaluated with the electrochemical method, and the result was accordant with that of MTT assay. The electrochemical estrogen screen method was simple, quickly, cheap, objective, and it exploits a new way for the evaluation of estrogenic effects of chemicals.

  16. Invasive Potential of Melanoma Cells Correlates with the Expression of MT1-MMP and Regulated by Modulating Its Association with Motility Receptors via N-Glycosylation on the Receptors

    Directory of Open Access Journals (Sweden)

    Amit Ranjan

    2014-01-01

    Full Text Available Matrix remodeling and invasion of basement membrane are the major determinants of malignant progression. Matrix degrading enzymes play a pivotal role in this process and have been shown to be regulated at multiple levels. Using high metastatic B16F10 and its invasive variant B16BL6 cells, we previously demonstrated that the expression of β1,6 branched N-oligosaccharides promotes cellular adhesion on different matrix components which in turn induces secretion of MMP9. The present investigations report that although the two cell lines do not differ in the expression of uPAR, expression of MT1-MMP is significantly higher on B16BL6 cells. Analysis of the transcripts of tissue inhibitors of matrix metalloproteinases (TIMPs showed that expression of both TIMP1 and TIMP2 correlates negatively with the invasive potential of cells. CD44 and β1 integrin, the two important receptors involved in motility, were identified to carry β1,6 branched N-oligosaccharides in an invasive potential dependent manner. However, their glycosylation status did not appear to influence their surface expression. Although glycosylation on CD44 had no effect, that on β1 integrin significantly affected association of β1 integrin with MT1-MMP. The results thus demonstrate that the cancer cells use multiple mechanisms for degradation of matrix in a controlled manner to couple it with movement for effective invasion.

  17. Invasive Potential of Melanoma Cells Correlates with the Expression of MT1-MMP and Regulated by Modulating Its Association with Motility Receptors via N-Glycosylation on the Receptors

    Science.gov (United States)

    Kalraiya, Rajiv D.

    2014-01-01

    Matrix remodeling and invasion of basement membrane are the major determinants of malignant progression. Matrix degrading enzymes play a pivotal role in this process and have been shown to be regulated at multiple levels. Using high metastatic B16F10 and its invasive variant B16BL6 cells, we previously demonstrated that the expression of β1,6 branched N-oligosaccharides promotes cellular adhesion on different matrix components which in turn induces secretion of MMP9. The present investigations report that although the two cell lines do not differ in the expression of uPAR, expression of MT1-MMP is significantly higher on B16BL6 cells. Analysis of the transcripts of tissue inhibitors of matrix metalloproteinases (TIMPs) showed that expression of both TIMP1 and TIMP2 correlates negatively with the invasive potential of cells. CD44 and β1 integrin, the two important receptors involved in motility, were identified to carry β1,6 branched N-oligosaccharides in an invasive potential dependent manner. However, their glycosylation status did not appear to influence their surface expression. Although glycosylation on CD44 had no effect, that on β1 integrin significantly affected association of β1 integrin with MT1-MMP. The results thus demonstrate that the cancer cells use multiple mechanisms for degradation of matrix in a controlled manner to couple it with movement for effective invasion. PMID:25180193

  18. Whole cell screen for inhibitors of pH homeostasis in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Crystal M Darby

    Full Text Available Bacterial pathogens like Mycobacterium tuberculosis (Mtb encounter acidic microenvironments in the host and must maintain their acid-base homeostasis to survive. A genetic screen identified two Mtb strains that cannot control intrabacterial pH (pHIB in an acidic environment; infection with either strain led to severe attenuation in mice. To search for additional proteins that Mtb requires to survive at low pH, we introduced a whole-cell screen for compounds that disrupt pHIB, along with counter-screens that identify ionophores and membrane perturbors. Application of these methods to a natural product library identified four compounds of interest, one of which may inhibit novel pathway(s. This approach yields compounds that may lead to the identification of pathways that allow Mtb to survive in acidic environments, a setting in which Mtb is resistant to most of the drugs currently used to treat tuberculosis.

  19. Barriers to bacterial motility on unsaturated surfaces

    DEFF Research Database (Denmark)

    Dechesne, Arnaud; Smets, Barth F.

    2013-01-01

    and their isogenic mutants unable to express various type of motility we aimed to quantify the physical limits of bacterial motility. Our results demonstrate how hydration controls bacterial motility under unsaturated conditions. They can form the base of improved biodegradation models that include microbial...

  20. Disease modeling and drug screening for neurological diseases using human induced pluripotent stem cells

    Institute of Scientific and Technical Information of China (English)

    Xiao-hong XU; Zhong ZHONG

    2013-01-01

    With the general decline of pharmaceutical research productivity,there are concerns that many components of the drug discovery process need to be redesigned and optimized.For example,the human immortalized cell lines or animal primary cells commonly used in traditional drug screening may not faithfully recapitulate the pathological mechanisms of human diseases,leading to biases in assays,targets,or compounds that do not effectively address disease mechanisms.Recent advances in stem cell research,especially in the development of induced pluripotent stem cell (iPSC) technology,provide a new paradigm for drug screening by permitting the use of human cells with the same genetic makeup as the patients without the typical quantity constraints associated with patient primary cells.In this article,we will review the progress made to date on cellular disease models using human stem cells,with a focus on patient-specific iPSCs for neurological diseases.We will discuss the key challenges and the factors that associated with the success of using stem cell models for drug discovery through examples from monogenic diseases,diseases with various known genetic components,and complex diseases caused by a combination of genetic,environmental and other factors.

  1. Enhanced diffusion of non-swimmers in a 3D bath of motile bacteria

    CERN Document Server

    Jepson, A; Schwarz-Linek, J; Morozov, A; Poon, W C K

    2013-01-01

    We show using differential dynamic microscopy that the diffusive motion of non-motile cells in a three-dimensional population of motile E. coli is enhanced by an amount that is strictly proportional to the active cell flux. While non-motile mutants without flagella and mutants with paralysed flagella have quite different thermal diffusivities and therefore hydrodynamic radii, their diffusivities are enhanced to the same extent by swimmers in the regime of cell densities explored here. Integrating the motion of non-swimmers caused by swimmers with finite persistence-length trajectories predicts quantitatively the observed linear dependence of enhanced diffusivity and active cell flux.

  2. Impact of Cell-Free Fetal DNA Screening on Patients’ Choice of Invasive Procedures after a Positive California Prenatal Screen Result

    Directory of Open Access Journals (Sweden)

    Forum T. Shah

    2014-07-01

    Full Text Available Until recently, maternal serum analyte levels paired with sonographic fetal nuchal translucency measurement was the most accurate prenatal screen available for Trisomies 18 and 21, (91% and 94% detection and false positive rates of 0.31% and 4.5% respectively. Women with positive California Prenatal Screening Program (CPSP results have the option of diagnostic testing to determine definitively if the fetus has a chromosomal abnormality. Cell-free fetal (cff- DNA screening for Trisomies 13, 18, and 21 was first offered in 2012, allowing women with positive screens to choose additional screening before diagnostic testing. Cff-DNA sensitivity rates are as high as 99.9% and 99.1%, with false positive rates of 0.4% and 0.1%, for Trisomies 18 and 21, respectively. A retrospective chart review was performed in 2012 on 500 CPSP referrals at the University of California, San Diego Thornton Hospital. Data were collected prior to and after the introduction of cff-DNA. There was a significant increase in the number of participants who chose to pursue additional testing and a decrease in the number of invasive procedures performed after cff-DNA screening was available. We conclude that as fetal aneuploidy screening improves, the number of invasive procedures will continue to decrease.

  3. Paper-based microreactor array for rapid screening of cell signaling cascades.

    Science.gov (United States)

    Huang, Chia-Hao; Lei, Kin Fong; Tsang, Ngan-Ming

    2016-08-01

    Investigation of cell signaling pathways is important for the study of pathogenesis of cancer. However, the related operations used in these studies are time consuming and labor intensive. Thus, the development of effective therapeutic strategies may be hampered. In this work, gel-free cell culture and subsequent immunoassay has been successfully integrated and conducted in a paper-based microreactor array. Study of the activation level of different kinases of cells stimulated by different conditions, i.e., IL-6 stimulation, starvation, and hypoxia, was demonstrated. Moreover, rapid screening of cell signaling cascades after the stimulations of HGF, doxorubicin, and UVB irradiation was respectively conducted to simultaneously screen 40 kinases and transcription factors. Activation of multi-signaling pathways could be identified and the correlation between signaling pathways was discussed to provide further information to investigate the entire signaling network. The present technique integrates most of the tedious operations using a single paper substrate, reduces sample and reagent consumption, and shortens the time required by the entire process. Therefore, it provides a first-tier rapid screening tool for the study of complicated signaling cascades. It is expected that the technique can be developed for routine protocol in conventional biological research laboratories. PMID:27377153

  4. High-throughput screens in mammalian cells using the CRISPR-Cas9 system.

    Science.gov (United States)

    Peng, Jingyu; Zhou, Yuexin; Zhu, Shiyou; Wei, Wensheng

    2015-06-01

    As a powerful genome-editing tool, the clustered regularly interspaced short palindromic repeats (CRISPR)-clustered regularly interspaced short palindromic repeats-associated protein 9 (Cas9) system has been quickly developed into a large-scale function-based screening strategy in mammalian cells. This new type of genetic library is constructed through the lentiviral delivery of single-guide RNA collections that direct Cas9 or inactive dead Cas9 fused with effectors to interrogate gene function or regulate gene transcription in targeted cells. Compared with RNA interference screening, the CRISPR-Cas9 system demonstrates much higher levels of effectiveness and reliability with respect to both loss-of-function and gain-of-function screening. Unlike the RNA interference strategy, a CRISPR-Cas9 library can target both protein-coding sequences and regulatory elements, including promoters, enhancers and elements transcribing microRNAs and long noncoding RNAs. This powerful genetic tool will undoubtedly accelerate the mechanistic discovery of various biological processes. In this mini review, we summarize the general procedure of CRISPR-Cas9 library mediated functional screening, system optimization strategies and applications of this new genetic toolkit.

  5. Large-scale RNA interference screening in mammalian cells identifies novel regulators of mutant huntingtin aggregation.

    Directory of Open Access Journals (Sweden)

    Tomoyuki Yamanaka

    Full Text Available In polyglutamine (polyQ diseases including Huntington's disease (HD, mutant proteins containing expanded polyQ stretch form aggregates in neurons. Genetic or RNAi screenings in yeast, C. elegans or Drosophila have identified multiple genes modifying polyQ aggregation, a few of which are confirmed effective in mammals. However, the overall molecular mechanism underlying polyQ protein aggregation in mammalian cells still remains obscure. We here perform RNAi screening in mouse neuro2a cells to identify mammalian modifiers for aggregation of mutant huntingtin, a causative protein of HD. By systematic cell transfection and automated cell image analysis, we screen ∼ 12000 shRNA clones and identify 111 shRNAs that either suppress or enhance mutant huntingtin aggregation, without altering its gene expression. Classification of the shRNA-targets suggests that genes with various cellular functions such as gene transcription and protein phosphorylation are involved in modifying the aggregation. Subsequent analysis suggests that, in addition to the aggregation-modifiers sensitive to proteasome inhibition, some of them, such as a transcription factor Tcf20, and kinases Csnk1d and Pik3c2a, are insensitive to it. As for Tcf20, which contains polyQ stretches at N-terminus, its binding to mutant huntingtin aggregates is observed in neuro2a cells and in HD model mouse neurons. Notably, except Pik3c2a, the rest of the modifiers identified here are novel. Thus, our first large-scale RNAi screening in mammalian system identifies previously undescribed genetic players that regulate mutant huntingtin aggregation by several, possibly mammalian-specific mechanisms.

  6. Control of actin-based motility through localized actin binding

    International Nuclear Information System (INIS)

    A wide variety of cell biological and biomimetic systems use actin polymerization to drive motility. It has been suggested that an object such as a bacterium can propel itself by self-assembling a high concentration of actin behind it, if it is repelled by actin. However, it is also known that it is essential for the moving object to bind actin. Therefore, a key question is how the actin tail can propel an object when it both binds and repels the object. We present a physically consistent Brownian dynamics model for actin-based motility that includes the minimal components of the dendritic nucleation model and allows for both attractive and repulsive interactions between actin and a moveable disc. We find that the concentration gradient of filamentous actin generated by polymerization is sufficient to propel the object, even with moderately strong binding interactions. Additionally, actin binding can act as a biophysical cap, and may directly control motility through modulation of network growth. Overall, this mechanism is robust in that it can drive motility against a load up to a stall pressure that depends on the Young’s modulus of the actin network and can explain several aspects of actin-based motility. (paper)

  7. Sodium affects the sperm motility in the European eel.

    Science.gov (United States)

    Vílchez, M Carmen; Morini, Marina; Peñaranda, David S; Gallego, Víctor; Asturiano, Juan F; Pérez, Luz

    2016-08-01

    The role of seminal plasma sodium and activation media sodium on sperm motility was examined by selectively removing the element from these two media, in European eel sperm. Sperm size (sperm head area) was also measured using an ASMA (Automated Sperm Morphometry Analyses) system, in the different conditions. Intracellular sodium [Na(+)]i was quantitatively analyzed by first time in the spermatozoa from a marine fish species. Measurement of [Na(+)]i was done before and after motility activation, by Flow Cytometry, using CoroNa Green AM as a dye. Sperm motility activation induced an increase in [Na(+)]i, from 96.72mM in quiescent stage to 152.21mM post-activation in seawater. A significant decrease in sperm head area was observed post-activation in seawater. There was a notable reduction in sperm motility when sodium was removed from the seminal plasma, but not when it was removed from the activation media. Sodium removal was also linked to a significant reduction in sperm head area in comparison to the controls. Our results indicate that the presence of the ion Na(+) in the seminal plasma (or in the extender medium) is necessary for the preservation of sperm motility in European eel, probably because it plays a role in maintaining an appropriate sperm cell volume in the quiescent stage of the spermatozoa. PMID:27085371

  8. Flagellar motility and structure in the hyperthermoacidophilic archaeon Sulfolobus solfataricus

    NARCIS (Netherlands)

    Szabo, Zalan; Sani, Musa; Groeneveld, Maarten; Zolghadr, Benham; Schelert, James; Albers, Sonja-Verena; Blum, Paul; Boekema, Egbert J.; Driessen, Arnold J. M.

    2007-01-01

    Flagellation in archaea is widespread and is involved in swimming motility. Here, we demonstrate that the structural flagellin gene from the crenarchaeaon Suffolobus soffiataricus is highly expressed in stationary-phase-grown cells and under unfavorable nutritional conditions. A mutant in a flagella

  9. Activation of Drosophila hemocyte motility by the ecdysone hormone

    Directory of Open Access Journals (Sweden)

    Christopher J. Sampson

    2013-11-01

    Drosophila hemocytes compose the cellular arm of the fly's innate immune system. Plasmatocytes, putative homologues to mammalian macrophages, represent ∼95% of the migratory hemocyte population in circulation and are responsible for the phagocytosis of bacteria and apoptotic tissues that arise during metamorphosis. It is not known as to how hemocytes become activated from a sessile state in response to such infectious and developmental cues, although the hormone ecdysone has been suggested as the signal that shifts hemocyte behaviour from quiescent to migratory at metamorphosis. Here, we corroborate this hypothesis by showing the activation of hemocyte motility by ecdysone. We induce motile behaviour in larval hemocytes by culturing them with 20-hydroxyecdysone ex vivo. Moreover, we also determine that motile cell behaviour requires the ecdysone receptor complex and leads to asymmetrical redistribution of both actin and tubulin cytoskeleton.

  10. miRNAs modified by dietary lipids in Caco-2 cells. A microarray screening

    Directory of Open Access Journals (Sweden)

    Lidia Daimiel

    2015-09-01

    Full Text Available We performed a screening of miRNAs regulated by dietary lipids in a cellular model of enterocytes, Caco-2 cells. Our aim was to describe new lipid-modified miRNAs with an implication in lipid homeostasis and cardiovascular disease [1,2]. For that purpose, we treated differentiated Caco-2 cells with micelles containing the assayed lipids (cholesterol, conjugated linoleic acid and docosahexaenoic acid and the screening of miRNAs was carried out by microarray using the μParaflo®Microfluidic Biochip Technology of LC Sciences (Huston, TX, USA. Experimental design, microarray description and raw data have been made available in the GEO database with the reference number of GSE59153. Here we described in detail the experimental design and methods used to obtain the relative expression data.

  11. Characterization of screen printed carbon counter electrodes for Co(II)/(III) mediated photoelectrochemical cells

    Energy Technology Data Exchange (ETDEWEB)

    Ghamouss, Fouad [CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, B.P. 92208, 44322, Nantes cedex 3 (France); Pitson, Robbin [Gwent Electronics Materials Ltd, Monmouth House, Mamhilad Park, Pontypool, NP4 0HZ (United Kingdom); Odobel, Fabrice [CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, B.P. 92208, 44322, Nantes cedex 3 (France); Boujtita, Mohammed, E-mail: mohammed.boujtita@univ-nantes.f [CEISAM, Universite de Nantes, CNRS, 2 rue de la Houssiniere, B.P. 92208, 44322, Nantes cedex 3 (France); Caramori, Stefano [Dipartmento di Chimica, Universita di Ferrara, Via L.Borsari, 46, 44100 Ferrara (Italy); Bignozzi, Carlo A., E-mail: g4s@unife.i [Dipartmento di Chimica, Universita di Ferrara, Via L.Borsari, 46, 44100 Ferrara (Italy)

    2010-09-01

    A screen printed carbon electrode associated with Tris(4,4'-di-tert-butyl-2,2'-bipyridine)Cobalt(II) as redox mediator was investigated as possible alternative to the volatile and corrosive iodide/triodide system in dye sensitized solar cells (DSSCs). We report here a first study on the screen printing technology for the manufacturing of an advanced and stable carbon cathode for dye sensitized solar cell. The electrode surface was characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) while the electrochemical response towards the cobalt complex was evaluated by using cyclic voltammetry. Photocurrent-voltage characteristics of DSSCs based on the new cathode/Cobalt complex system were 30% lower than those recorded with Pt/iodide.

  12. Gender effects on esophageal motility

    Directory of Open Access Journals (Sweden)

    Dantas R.O.

    1998-01-01

    Full Text Available It has been suggested that there are no gender effects on esophageal motility. However, in previous studies the subjects did not perform multiple swallows and the quantitative features of esophageal contractions were not evaluated. In order to investigate the gender effects on esophageal motility we studied 40 healthy normal volunteers, 20 men aged 37 ± 15 years (mean ± SD, and 20 women aged 38 ± 14 years. We used the manometric method with an eight-lumen polyvinyl catheter and continuous perfusion. The upper and lower esophageal sphincter pressures were measured by the rapid pull-through method. With the catheter positioned with one lumen opening in the lower esophageal sphincter, and the others at 5, 10 and 15 cm above the sphincter, ten swallows of a 5-ml water bolus alternated with ten dry swallows were performed. Statistical analysis was done by the Student t-test and Mann-Whitney test. Gender differences (P<0.05 were observed for wet swallows in the duration of contractions 5 cm above the lower esophageal sphincter (men: 3.7 ± 0.2 s, women: 4.5 ± 0.3 s, mean ± SEM, and in the velocity of contractions from 15 to 10 cm above the lower esophageal sphincter (men: 4.7 ± 0.3 cm/s, women: 3.5 ± 0.2 cm/s. There was no difference (P>0.05 in sphincter pressure, duration and percentage of complete lower esophageal sphincter relaxation, amplitude of contractions, or in the number of failed, multipeaked and synchronous contractions. We conclude that gender may cause some differences in esophageal motility which, though of no clinical significance, should be taken into consideration when interpreting esophageal motility tests.

  13. Common basis for cellular motility

    OpenAIRE

    Zot, Henry G.; Javier E Hasbun; Minh, Nguyen Van

    2015-01-01

    Motility is characteristic of life, but a common basis for movement has remained to be identified. Diverse systems in motion shift between two states depending on interactions that turnover at the rate of an applied cycle of force. Although one phase of the force cycle terminates the decay of the most recent state, continuation of the cycle of force regenerates the original decay process in a recursive cycle. By completing a cycle, kinetic energy is transformed into probability of sustaining ...

  14. Maternal Cell free DNA based screening for fetal microdeletion and the importance of careful diagnostic follow up

    OpenAIRE

    Yatsenko, Svetlana A.; Peters, David; Saller, Devereux; Chu, Tianjiao; Clemens, Michelle; Rajkovic, Aleksandar

    2015-01-01

    Background Noninvasive prenatal screening (NIPS) by next-generation sequencing of cell free DNA (cfDNA) in maternal plasma is used to screen for common aneuploidies such as trisomy 21, in high risk pregnancies. NIPS can identify fetal genomic microdeletions, however sensitivity and specificity have not been systematically evaluated. Commercial companies have begun to offer expanded panels including screening for common microdeletion syndromes such as 22q11.2 deletion (DiGeorge syndrome) witho...

  15. High-throughput methods for screening liposome-macrophage cell interaction.

    OpenAIRE

    Kelly, Ciara; Lawlor, Ciaran; Burke, Colin; Barlow, James W; Ramsey, Joanne M; Jefferies, Caroline; Cryan, Sally-Ann

    2014-01-01

    Carriers are often an essential element of drug delivery, bestowing attributes to their cargo such as biocompatibility, enhanced delivery, extended half-life and efficacy as well as mediating specific targeting at a tissue, cell or intracellular level. Liposomes and lipid-based carriers have been investigated for decades for this purpose, many achieving clinical approval including products such as Doxil® and Myocet™. Large-scale compound screens are routinely carried out in the field of drug ...

  16. Screening of cell-drug interactions using acoustic trapping and MALDI MS

    OpenAIRE

    Teppo, Jaakko

    2015-01-01

    The properties of liquid and gas flows in microscale systems differ from those in macroscale; microfluidics is a field of science in which these properties are investigated and utilized for the development of microscale systems. Acoustofluidics is a branch of microfluidics focusing on the movement (acoustophoresis) or localization (acoustic trapping) of particles in microchannels using ultrasound. In this work, the suitability of a new miniaturized method for the screening of cell-drug in...

  17. In-vitro screening of organotin compounds and sediment extracts for cytotoxicity to fish cells

    OpenAIRE

    Giltrap, Michelle; Macken, Ailbhe; McHugh, Brendan; McGovern, Evin; Foley, Barry; Davoren, Maria

    2011-01-01

    The present study reports an in vitro screening method for contaminants in sediment samples utilizing an RTG-2 cell line. This technique integrates cytotoxicity testing with analytical chemistry with the aim of achieving a toxicity evaluation of the sediment sample. The toxic effect of individual organotin (OT) compounds and their presence in the sediment sample is the focus of the present study; however, other contaminants are also discussed. The following OT compounds: tributyltin (TBT), di...

  18. Genome-wide RNAi Screen Identifies Networks Involved in Intestinal Stem Cell Regulation in Drosophila

    OpenAIRE

    Xiankun Zeng; Lili Han; Shree Ram Singh; Hanhan Liu; Ralph A. Neumüller; Dong Yan; Yanhui Hu; Ying Liu; Wei Liu; Xinhua Lin; Steven X. Hou

    2015-01-01

    The intestinal epithelium is the most rapidly self-renewing tissue in adult animals and maintained by intestinal stem cells (ISCs) in both Drosophila and mammals. To comprehensively identify genes and pathways that regulate ISC fates, we performed a genome-wide transgenic RNAi screen in adult Drosophila intestine and identified 405 genes that regulate ISC maintenance and lineage-specific differentiation. By integrating these genes into publicly available interaction databases, we further deve...

  19. Genome-wide RNAi Screen Identifies Networks Involved in Intestinal Stem Cell Regulation in Drosophila

    OpenAIRE

    Zeng, Xiankun; Han, Lili; Singh, Shree Ram; Liu, Hanhan; Neumüller, Ralph A.; Yan, Dong; Hu, Yanhui; Liu, Ying; Liu, Wei; Lin, Xinhua; Steven X Hou

    2015-01-01

    The intestinal epithelium is the most rapidly self-renewing tissue in adult animals and maintained by intestinal stem cells (ISCs) in both Drosophila and mammals. To comprehensively identify genes and pathways that regulate ISC fates, we performed a genome-wide transgenic RNAi screen in adult Drosophila intestine and identified 405 genes that regulate ISC maintenance and lineage-specific differentiation. Through integrating these genes into publicly available interaction databases, we further...

  20. Cervical acid phosphatase detection: A guide to abnormal cells in cytology smear screening for cervical cancer

    OpenAIRE

    Deb Prabal; Iyer Venkateswaran; Bhatla Neerja; Markovic O; Verma Kusum

    2008-01-01

    Background: Cervical acid phosphatase-Papanicolaou (CAP-PAP) test has recently been described for detection of acid phosphatase enzyme in abnormal squamous cells, and has been proposed as a biomarker-based technology for the screening of cervical cancer. Materials and Methods: Eighty-one consecutive cervical smears were subjected to routine Papanicolaou (Pap) staining as well as CAP-PAP, which combined cytochemical staining for acid phosphatase with modified Pap stain. Statistical evaluation ...

  1. Gene expression in Pseudomonas aeruginosa swarming motility

    Directory of Open Access Journals (Sweden)

    Déziel Eric

    2010-10-01

    Full Text Available Abstract Background The bacterium Pseudomonas aeruginosa is capable of three types of motilities: swimming, twitching and swarming. The latter is characterized by a fast and coordinated group movement over a semi-solid surface resulting from intercellular interactions and morphological differentiation. A striking feature of swarming motility is the complex fractal-like patterns displayed by migrating bacteria while they move away from their inoculation point. This type of group behaviour is still poorly understood and its characterization provides important information on bacterial structured communities such as biofilms. Using GeneChip® Affymetrix microarrays, we obtained the transcriptomic profiles of both bacterial populations located at the tip of migrating tendrils and swarm center of swarming colonies and compared these profiles to that of a bacterial control population grown on the same media but solidified to not allow swarming motility. Results Microarray raw data were corrected for background noise with the RMA algorithm and quantile normalized. Differentially expressed genes between the three conditions were selected using a threshold of 1.5 log2-fold, which gave a total of 378 selected genes (6.3% of the predicted open reading frames of strain PA14. Major shifts in gene expression patterns are observed in each growth conditions, highlighting the presence of distinct bacterial subpopulations within a swarming colony (tendril tips vs. swarm center. Unexpectedly, microarrays expression data reveal that a minority of genes are up-regulated in tendril tip populations. Among them, we found energy metabolism, ribosomal protein and transport of small molecules related genes. On the other hand, many well-known virulence factors genes were globally repressed in tendril tip cells. Swarm center cells are distinct and appear to be under oxidative and copper stress responses. Conclusions Results reported in this study show that, as opposed to

  2. Pantoea stewartii subsp. stewartii exhibits surface motility, which is a critical aspect of Stewart's wilt disease development on maize.

    Science.gov (United States)

    Herrera, Carmen M; Koutsoudis, Maria D; Wang, Xiaolei; von Bodman, Susanne B

    2008-10-01

    Pantoea stewartii subsp. stewartii is a plant-pathogenic bacterium that causes Stewart's vascular wilt in maize. The organism is taxonomically described as aflagellated and nonmotile. We recently showed that P. stewartii colonizes the xylem of maize as sessile, cell-wall-adherent biofilms. Biofilm formation is a developmental process that generally involves some form of surface motility. For that reason, we reexamined the motility properties of P. stewartii DC283 based on the assumption that the organism requires some form of surface motility for biofilm development. Here, we show that the organism is highly motile on agar surfaces. This motility is flagella dependent, shown by the fact that a fliC mutant, impaired in flagellin subunit synthesis, is nonmotile. Motility also requires the production of stewartan exopolysaccharide. Moreover, surface motility plays a significant role in the colonization of the plant host. PMID:18785831

  3. Induction of iodide uptake in transformed thyrocytes: a compound screening in cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Eleonore [University of Tuebingen, Department of Endocrinology, Metabolism, Nephrology and Clinical Chemistry, Internal Medicine, Tuebingen (Germany); Brossart, Peter [University of Tuebingen, Department of Haematology, Oncology, Immunology and Rheumatology, Internal Medicine, Tuebingen (Germany); Wahl, Richard [University of Tuebingen, Department of Endocrinology, Metabolism, Nephrology and Clinical Chemistry, Internal Medicine, Tuebingen (Germany); Department IV, Internal Medicine, Tuebingen (Germany)

    2009-05-15

    Retinoic acid presently is the most advanced agent able to improve the efficacy of radioiodine therapy in differentiated thyroid carcinoma. In order to identify compounds with higher efficacy a panel of pharmacologically well-characterized compounds with antitumour action in solid cancer cell lines was screened. The effects of the compounds on iodide uptake, cell number, proliferation and apoptosis were evaluated. In general, compounds were more effective in cell lines derived from more aggressive tumours. The effectiveness in terms of number of responsive cell lines and maximal increase in iodide uptake achieved decreased in the order: APHA > valproic acid {approx} sirolimus {approx} arsenic trioxide > retinoic acid {approx} lovastatin > apicidine {approx} azacytidine {approx} retinol {approx} rosiglitazone {approx} bortezomib. We hypothesize that testing of cells from primary tumours or metastases in patients may be a way to identify compounds with optimum therapeutic efficacy for individualized treatment. (orig.)

  4. Differentially pumped spray deposition as a rapid screening tool for organic and perovskite solar cells

    Science.gov (United States)

    Jung, Yen-Sook; Hwang, Kyeongil; Scholes, Fiona H.; Watkins, Scott E.; Kim, Dong-Yu; Vak, Doojin

    2016-01-01

    We report a spray deposition technique as a screening tool for solution processed solar cells. A dual-feed spray nozzle is introduced to deposit donor and acceptor materials separately and to form blended films on substrates in situ. Using a differential pump system with a motorised spray nozzle, the effect of film thickness, solution flow rates and the blend ratio of donor and acceptor materials on device performance can be found in a single experiment. Using this method, polymer solar cells based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PC61BM) are fabricated with numerous combinations of thicknesses and blend ratios. Results obtained from this technique show that the optimum ratio of materials is consistent with previously reported values confirming this technique is a very useful and effective screening method. This high throughput screening method is also used in a single-feed configuration. In the single-feed mode, methylammonium iodide solution is deposited on lead iodide films to create a photoactive layer of perovskite solar cells. Devices featuring a perovskite layer fabricated by this spray process demonstrated a power conversion efficiencies of up to 7.9%. PMID:26853266

  5. Differentially pumped spray deposition as a rapid screening tool for organic and perovskite solar cells

    Science.gov (United States)

    Jung, Yen-Sook; Hwang, Kyeongil; Scholes, Fiona H.; Watkins, Scott E.; Kim, Dong-Yu; Vak, Doojin

    2016-02-01

    We report a spray deposition technique as a screening tool for solution processed solar cells. A dual-feed spray nozzle is introduced to deposit donor and acceptor materials separately and to form blended films on substrates in situ. Using a differential pump system with a motorised spray nozzle, the effect of film thickness, solution flow rates and the blend ratio of donor and acceptor materials on device performance can be found in a single experiment. Using this method, polymer solar cells based on poly(3-hexylthiophene) (P3HT):(6,6)-phenyl C61 butyric acid methyl ester (PC61BM) are fabricated with numerous combinations of thicknesses and blend ratios. Results obtained from this technique show that the optimum ratio of materials is consistent with previously reported values confirming this technique is a very useful and effective screening method. This high throughput screening method is also used in a single-feed configuration. In the single-feed mode, methylammonium iodide solution is deposited on lead iodide films to create a photoactive layer of perovskite solar cells. Devices featuring a perovskite layer fabricated by this spray process demonstrated a power conversion efficiencies of up to 7.9%.

  6. Screen printed silver top electrode for efficient inverted organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junwoo [Department of Printed Electronics, Korea Institute of Machinery & Materials (KIMM), Daejeon (Korea, Republic of); Duraisamy, Navaneethan [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of); Lee, Taik-Min [Department of Printed Electronics, Korea Institute of Machinery & Materials (KIMM), Daejeon (Korea, Republic of); Kim, Inyoung, E-mail: ikim@kimm.re.kr [Department of Printed Electronics, Korea Institute of Machinery & Materials (KIMM), Daejeon (Korea, Republic of); Choi, Kyung-Hyun, E-mail: amm@jejunu.ac.kr [Department of Mechatronics Engineering, Jeju National University, Jeju (Korea, Republic of)

    2015-10-15

    Highlights: • Screen printing of silver pattern. • X-ray diffraction pattern confirmed the face centered cubic structure of silver. • Uniform surface morphology of silver pattern with sheet resistance of 0.06 Ω/sq. • The power conversion efficiency of fabricated solar cell is found to be 2.58%. - Abstract: The present work is mainly focused on replacement of the vacuum process for top electrode fabrication in organic solar cells. Silver top electrode deposited through solution based screen printing on pre-deposited polymeric thin film. The solution based printing technology provides uniform top electrode without damaging the underlying organic layers. The surface crystallinity and surface morphology of silver top electrode are examined through X-ray diffraction, field-emission scanning electron microscope and atomic force microscope. The purity of silver is examined through X-ray energy dispersive spectroscopy. The top electrode exhibits face centered cubic structure with homogeneous morphology. The sheet resistance of top electrode is found to be 0.06 Ω/sq and an average pattern thickness of ∼15 μm. The power conversion efficiency is 2.58%. Our work demonstrates that the solution based screen printing is a significant role in the replacement of vacuum process for the fabrication of top electrode in organic solar cells.

  7. In silico reconstitution of actin-based symmetry breaking and motility.

    Directory of Open Access Journals (Sweden)

    Mark J Dayel

    2009-09-01

    Full Text Available Eukaryotic cells assemble viscoelastic networks of crosslinked actin filaments to control their shape, mechanical properties, and motility. One important class of actin network is nucleated by the Arp2/3 complex and drives both membrane protrusion at the leading edge of motile cells and intracellular motility of pathogens such as Listeria monocytogenes. These networks can be reconstituted in vitro from purified components to drive the motility of spherical micron-sized beads. An Elastic Gel model has been successful in explaining how these networks break symmetry, but how they produce directed motile force has been less clear. We have combined numerical simulations with in vitro experiments to reconstitute the behavior of these motile actin networks in silico using an Accumulative Particle-Spring (APS model that builds on the Elastic Gel model, and demonstrates simple intuitive mechanisms for both symmetry breaking and sustained motility. The APS model explains observed transitions between smooth and pulsatile motion as well as subtle variations in network architecture caused by differences in geometry and conditions. Our findings also explain sideways symmetry breaking and motility of elongated beads, and show that elastic recoil, though important for symmetry breaking and pulsatile motion, is not necessary for smooth directional motility. The APS model demonstrates how a small number of viscoelastic network parameters and construction rules suffice to recapture the complex behavior of motile actin networks. The fact that the model not only mirrors our in vitro observations, but also makes novel predictions that we confirm by experiment, suggests that the model captures much of the essence of actin-based motility in this system.

  8. Bacterial signaling and motility: Sure bets

    Energy Technology Data Exchange (ETDEWEB)

    Zhulin, Igor B [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2008-01-01

    The IX International Conference on Bacterial Locomotion and Signal Transduction (BLAST IX) was held from 14 to 19 January 2007 in Laughlin, NV, a town in the Mojave Desert on the Nevada-Arizona border near old Route 66 and along the banks of the Colorado River. This area is a home to rattlesnakes, sagebrush, abandoned gold mines, and compulsive gamblers. What better venue could scientists possibly dream of for a professional meeting? So there they were, about 190 scientists gathered in the Aquarius Casino Resort, the largest hotel and casino in Laughlin, discussing the latest advances in the field. Aside from a brief excursion to an abandoned gold mine and a dinner cruise on the Colorado River, the scientists focused on nothing but their data and hypotheses, in spirited arguments and rebuttals, and outlined their visions and future plans in a friendly and open environment. The BLAST IX program was dense, with nearly 50 talks and over 90 posters. For that reason, this meeting report will not attempt to be comprehensive; instead it will first provide general background information on the central topics of the meeting and then highlight only a few talks that were of special interest to us and hopefully to the wider scientific community. We will also attempt to articulate some of the future directions or perspectives to the best of our abilities. The best known and understood bacterial motility mechanism is swimming powered by flagella. The rotation of bacterial flagella drives this form of bacterial movement in an aqueous environment. A bacterial flagellum consists of a helical filament attached to the cell body through a complex structure known as the hook-basal body, which drives flagellar rotation. The essential components of the basal body are the MotA-MotB motor-stator proteins bound to the cytoplasmic membrane. These stator proteins interact with proteins that comprise the supramembrane and cytoplasmic rings, which are components of the motor imbedded in the

  9. Cytotoxicity screening of Bangladeshi medicinal plant extracts on pancreatic cancer cells

    Directory of Open Access Journals (Sweden)

    Abbasi Atiya

    2010-09-01

    Full Text Available Abstract Background There has been a long standing interest in the identification of medicinal plants and derived natural products for developing cancer therapeutics. Our study focuses upon pancreatic cancer, due to its high mortality rate, that is attributed in part to the lack of an effective chemotherapeutic agent. Previous reports on the use of medicinal plant extracts either alone or alongside conventional anticancer agents in the treatment of this cancer have shown promising results. This work aims to investigate the therapeutic properties of a library of medicinal plants from Bangladesh. Methods 56 extracts of 44 unique medicinal plants were studied. The extracts were screened for cytotoxicity against the pancreatic adenocarcinoma cell line Panc-1, using a label-free biosensor assay. The top cytotoxic extracts identified in this screen were tested on two additional pancreatic cancer cell lines (Mia-Paca2 and Capan-1 and a fibroblast cell line (Hs68 using an MTT proliferation assay. Finally, one of the most promising extracts was studied using a caspase-3 colorimetric assay to identify induction of apoptosis. Results Crude extracts of Petunia punctata, Alternanthera sessilis, and Amoora chittagonga showed cytotoxicity to three cancer cell lines with IC50 values ranging between 20.3 - 31.4 μg/mL, 13.08 - 34.9 μg/mL, and 42.8 - 49.8 μg/mL, respectively. Furthermore, treatment of Panc-1 cells with Petunia punctata was shown to increase caspase-3 activity, indicating that the observed cytotoxicity was mediated via apoptosis. Only Amoora chittagonga showed low cytotoxicity to fibroblast cells with an IC50 value > 100 μg/mL. Conclusion Based upon the initial screening work reported here, further studies aimed at the identification of active components of these three extracts and the elucidation of their mechanisms as cancer therapeutics are warranted.

  10. Screening of Highly Expressed CPEΔN Lung Cancer H1299 Cells

    OpenAIRE

    Sun, Jing; Zhang, Guirong; Wang, Hongyue; Shen, Hui

    2015-01-01

    Background and objective The N-terminal truncated carboxypeptidase E (CPEΔN) protein is a novel biomarker of tumor metastasis. This study screened the H1299 cell line with a highly expressed CPEΔN gene for in vivo imaging experiment. Methods Human CPEΔN gene was cloned into the luciferase lentiviral vector. H1299 cells transduced with CPEΔN or control lentiviral vectors were selected with 2 µg/mL puromycin. The expression of CPEΔN was identified through Western blot analysis, and luciferase a...

  11. Fragment-Based Whole Cell Screen Delivers Hits against M. tuberculosis and Non-tuberculous Mycobacteria.

    Science.gov (United States)

    Moreira, Wilfried; Lim, Jia Jie; Yeo, Si Ying; Ramanujulu, Pondy M; Dymock, Brian W; Dick, Thomas

    2016-01-01

    Reactive multi-target 'fragment drugs' represent critical components of current tuberculosis regimens. These compounds, such as pyrazinamide, are old synthetic antimycobacterials that are activated inside Mycobacterium tuberculosis bacilli and are smaller than the usual drug-like, single-target molecules. Based on the success of small 'dirty' drugs in the chemotherapy of tuberculosis, we suggested previously that fragment-based whole cell screens should be introduced in our current antimycobacterial drug discovery efforts. Here, we carried out such a screen and characterized bactericidal activity, selectivity and spectrum of hits we obtained. A library of 1725 fragments was tested at a single concentration for growth inhibitory activity against M. bovis BCG as screening strain and 38 of 116 primary hits were confirmed in dose response analyses to be active against virulent M. tuberculosis. Bacterial kill experiments showed that most hits displayed bactericidal activity at their minimal inhibitory concentration. Cytotoxicity assays established that a large proportion of hits displayed a favorable selectivity index for mammalian cells. Importantly, one third of M. tuberculosis active fragments were also active against M. abscessus and M. avium, two emerging non-tuberculous mycobacterial (NTM) pathogens, opening the opportunity to develop broad spectrum antimycobacterials. Activity determination against Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa) bacteria, as well as fungi (Candida albicans, Cryptococcus neoformans) showed only a small overlap indicating a generally narrow spectrum of these novel antimicrobial hits for mycobacteria. In conclusion, we carried out the first fragment-based whole cell screen against bacteria and identified a substantial number of hits with excellent physicochemical properties and dual activity against M. tuberculosis and NTM pathogens

  12. 19.4%-efficient large-area fully screen-printed silicon solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Gatz, Sebastian; Hannebauer, Helge; Hesse, Rene; Werner, Florian; Schmidt, Arne; Dullweber, Thorsten; Bothe, Karsten [Institute for Solar Energy Hamelin (ISFH), Am Ohrberg 1, 31860 Emmerthal (Germany); Schmidt, Jan; Brendel, Rolf [Institute for Solar Energy Hamelin (ISFH), Am Ohrberg 1, 31860 Emmerthal (Germany); Institute of Solid-State Physics, University of Hannover, Appelstrasse 2, 30167 Hannover (Germany)

    2011-04-15

    We demonstrate industrially feasible large-area solar cells with passivated homogeneous emitter and rear achieving energy conversion efficiencies of up to 19.4% on 125 x 125 mm{sup 2} p-type 2-3 {omega} cm boron-doped Czochralski silicon wafers. Front and rear metal contacts are fabricated by screen-printing of silver and aluminum paste and firing in a conventional belt furnace. We implement two different dielectric rear surface passivation stacks: (i) a thermally grown silicon dioxide/silicon nitride stack and (ii) an atomic-layer-deposited aluminum oxide/silicon nitride stack. The dielectrics at the rear result in a decreased surface recombination velocity of S{sub rear} = 70 cm/s and 80 cm/s, and an increased internal IR reflectance of up to 91% corresponding to an improved J{sub sc} of up to 38.9 mA/cm{sup 2} and V{sub oc} of up to 664 mV. We observe an increase in cell efficiency of 0.8% absolute for the cells compared to 18.6% efficient reference solar cells featuring a full-area aluminum back surface field. To our knowledge, the energy conversion efficiency of 19.4% is the best value reported so far for large area screen-printed solar cells. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Optimizing human embryonic stem cells differentiation efficiency by screening size-tunable homogenous embryoid bodies.

    Science.gov (United States)

    Moon, Sung-Hwan; Ju, Jongil; Park, Soon-Jung; Bae, Daekyeong; Chung, Hyung-Min; Lee, Sang-Hoon

    2014-07-01

    Human embryonic stem cells (hESCs) are generally induced to differentiate by forming spherical structures termed embryoid bodies (EBs) in the presence of soluble growth factors. hEBs are generated by suspending small clumps of hESC colonies; however, the resulting hEBs are heterogeneous because this method lacks the ability to control the number of cells in individual EBs. This heterogeneity affects factors that influence differentiation such as cell-cell contact and the diffusion of soluble factors, and consequently, the differentiation capacity of each EB varies. Here, we fabricated size-tunable concave microwells to control the physical environment, thereby regulating the size of EBs formed from single hESCs. Defined numbers of single hESCs were forced to aggregate and generate uniformly sized EBs with high fidelity, and the size of the EBs was controlled using concave microwells of different diameters. Differentiation patterns in H9- and CHA15-hESCs were affected by EB size in both the absence and presence of growth factors. By screening EB size in the presence of various BMP4 concentrations, a two-fold increase in endothelial cell differentiation was achieved. Because each hESC line has unique characteristics, the findings of this study demonstrate that concave microwells could be used to screen different EB sizes and growth factor concentrations to optimize differentiation for each hESC line.

  14. Discovery of T cell antigens by high-throughput screening of synthetic minigene libraries.

    Directory of Open Access Journals (Sweden)

    Brian D Hondowicz

    Full Text Available The identification of novel T cell antigens is central to basic and translational research in autoimmunity, tumor immunology, transplant immunology, and vaccine design for infectious disease. However, current methods for T cell antigen discovery are low throughput, and fail to explore a wide range of potential antigen-receptor interactions. To overcome these limitations, we developed a method in which programmable microarrays are used to cost-effectively synthesize complex libraries of thousands of minigenes that collectively encode the content of hundreds of candidate protein targets. Minigene-derived mRNA are transfected into autologous antigen presenting cells and used to challenge complex populations of purified peripheral blood CD8+ T cells in multiplex, parallel ELISPOT assays. In this proof-of-concept study, we apply synthetic minigene screening to identify two novel pancreatic islet autoantigens targeted in a patient with Type I Diabetes. To our knowledge, this is the first successful screen of a highly complex, synthetic minigene library for identification of a T cell antigen. In principle, responses against the full protein complement of any tissue or pathogen can be assayed by this approach, suggesting that further optimization of synthetic libraries holds promise for high throughput antigen discovery.

  15. Screening for intermediate and severe forms of thalassaemia in discarded red blood cells: optimization and feasibility.

    Science.gov (United States)

    George, Elizabeth; Lai, Mei I; Teh, Lai Kuan; Ramasamy, Rajesh; Goh, Ern Huei; Asokan, Kamalan; Tan, J A M A; Vasudevan, Maithili; Low, Sharon

    2011-12-01

    Detection and quantification of Hb subtypes of human blood is integral to presumptive identification of thalassaemias. It has been used in neonatal screening of thalassaemia and Hb variants. The use of discarded red blood cells following processing of the cord blood for stem cells provides readily available diagnostic material for thalassaemia screening. In this study, we determined the range of Hb subtypes in 195 consecutive cord blood samples collected for cord blood banking. The 'cord blood samples' analysed were those of the remaining red blood cells after the cord blood was processed for stem cell storage. Quantification of Hb subtypes by high performance liquid chromatography (HPLC) was done on BioRad Variant II Hb testing system. Only 73 (36.5%) of the samples could be analyzed neat without dilution. With a 1:300 dilution with wash solution the acceptable area as recommended by the manufacturer for reading of a C-gram within the 1 to 3 million ranges were achieved in all. Eighteen (9%) 12 showed classical Hb Barts (y4) prerun peaks were confirmed by Sebia Hydrasys automated Hb gel electrophoresis and quantified by Sebia Capillarys 2 capillary electrophoresis. Only 1 (0.5%) was presumptively identified with HbH disease. Due to the limited number of samples no beta-thalassaemia major, Hb E beta-thalassaemia and Hb Barts hydrops fetalis were found. The HPLC assay was possible at a cost US$ 5 per sample and a turnover time of 10 samples per hour without technical difficulties. This study reports an effective and valuable protocol for thalassaemia screening in red blood cells which would otherwise be discarded during cord blood processing. Cord blood with severe and intermediate forms of thalassaemia can be preselected and not stored. PMID:22390095

  16. Microbioreactor array screening of Wnt modulators and microenvironmental factors in osteogenic differentiation of mesenchymal progenitor cells.

    Directory of Open Access Journals (Sweden)

    Jessica E Frith

    Full Text Available Cellular microenvironmental conditions coordinate to regulate stem cell populations and their differentiation. Mesenchymal precursor cells (MPCs, which have significant potential for a wide range of therapeutic applications, can be expanded or differentiated into osteo- chondro- and adipogenic lineages. The ability to establish, screen, and control aspects of the microenvironment is paramount if we are to elucidate the complex interplay of signaling events that direct cell fate. Whilst modulation of Wnt signaling may be useful to direct osteogenesis in MPCs, there is still significant controversy over how the Wnt signaling pathway influences osteogenesis. In this study, we utilised a full-factorial microbioreactor array (MBA to rapidly, combinatorially screen several Wnt modulatory compounds (CHIR99021, IWP-4 and IWR-1 and characterise their effects upon osteogenesis. The MBA screening system showed excellent consistency between donors and experimental runs. CHIR99021 (a Wnt agonist had a profoundly inhibitory effect upon osteogenesis, contrary to expectations, whilst the effects of the IWP-4 and IWR-1 (Wnt antagonists were confirmed to be inhibitory to osteogenesis, but to a lesser extent than observed for CHIR99021. Importantly, we demonstrated that these results were translatable to standard culture conditions. Using RT-qPCR of osteogenic and Wnt pathway markers, we showed that CHIR exerted its effects via inhibition of ALP and SPP1 expression, even though other osteogenic markers (RUNX2, MSX2, DLX, COL1A1 were upregulated. Lastly, this MBA platform, due to the continuous provision of medium from the first to the last of ten serially connected culture chambers, permitted new insight into the impacts of paracrine signaling on osteogenic differentiation in MPCs, with factors secreted by the MPCs in upstream chambers enhancing the differentiation of cells in downstream chambers. Insights provided by this cell-based assay system will be key to

  17. Gradient Technology for High-Throughput Screening of Interactions between Cells and Nanostructured Materials

    Directory of Open Access Journals (Sweden)

    Andrew Michelmore

    2012-01-01

    Full Text Available We present a novel substrate suitable for the high-throughput analysis of cell response to variations in surface chemistry and nanotopography. Electrochemical etching was used to produce silicon wafers with nanopores between 10 and 100 nm in diameter. Over this substrate and flat silicon wafers, a gradient film ranging from hydrocarbon to carboxylic acid plasma polymer was deposited, with the concentration of surface carboxylic acid groups varying between 0.7 and 3% as measured by XPS. MG63 osteoblast-like cells were then cultured on these substrates and showed greatest cell spreading and adhesion onto porous silicon with a carboxylic acid group concentration between 2-3%. This method has great potential for high-throughput screening of cell-material interaction with particular relevance to tissue engineering.

  18. Automated cell analysis tool for a genome-wide RNAi screen with support vector machine based supervised learning

    Science.gov (United States)

    Remmele, Steffen; Ritzerfeld, Julia; Nickel, Walter; Hesser, Jürgen

    2011-03-01

    RNAi-based high-throughput microscopy screens have become an important tool in biological sciences in order to decrypt mostly unknown biological functions of human genes. However, manual analysis is impossible for such screens since the amount of image data sets can often be in the hundred thousands. Reliable automated tools are thus required to analyse the fluorescence microscopy image data sets usually containing two or more reaction channels. The herein presented image analysis tool is designed to analyse an RNAi screen investigating the intracellular trafficking and targeting of acylated Src kinases. In this specific screen, a data set consists of three reaction channels and the investigated cells can appear in different phenotypes. The main issue of the image processing task is an automatic cell segmentation which has to be robust and accurate for all different phenotypes and a successive phenotype classification. The cell segmentation is done in two steps by segmenting the cell nuclei first and then using a classifier-enhanced region growing on basis of the cell nuclei to segment the cells. The classification of the cells is realized by a support vector machine which has to be trained manually using supervised learning. Furthermore, the tool is brightness invariant allowing different staining quality and it provides a quality control that copes with typical defects during preparation and acquisition. A first version of the tool has already been successfully applied for an RNAi-screen containing three hundred thousand image data sets and the SVM extended version is designed for additional screens.

  19. Twist induces epithelial-mesenchymal transition and cell motility in breast cancer via ITGB1-FAK/ILK signaling axis and its associated downstream network.

    Science.gov (United States)

    Yang, Jiajia; Hou, Yixuan; Zhou, Mingli; Wen, Siyang; Zhou, Jian; Xu, Liyun; Tang, Xi; Du, Yan-e; Hu, Ping; Liu, Manran

    2016-02-01

    Twist, a highly conserved basic Helix-Loop-Helix transcription factor, functions as a major regulator of epithelial-mesenchymal transition (EMT) and tumor metastasis. In different cell models, signaling pathways such as TGF-β, MAPK/ERK, WNT, AKT, JAK/STAT, Notch, and P53 have also been shown to play key roles in the EMT process, yet little is known about the signaling pathways regulated by Twist in tumor cells. Using iTRAQ-labeling combined with 2D LC-MS/MS analysis, we identified 194 proteins with significant changes of expression in MCF10A-Twist cells. These proteins reportedly play roles in EMT, cell junction organization, cell adhesion, and cell migration and invasion. ECM-receptor interaction, MAPK, PI3K/AKT, P53 and WNT signaling were found to be aberrantly activated in MCF10A-Twist cells. Ingenuity Pathways Analysis showed that integrin β1 (ITGB1) acts as a core regulator in linking integrin-linked kinase (ILK), Focal-adhesion kinase (FAK), MAPK/ERK, PI3K/AKT, and WNT signaling. Increased Twist and ITGB1 are associated with breast tumor progression. Twist transcriptionally regulates ITGB1 expression. Over-expression of ITGB1 or Twist in MCF10A led to EMT, activation of FAK/ILK, MAPK/ERK, PI3K/AKT, and WNT signaling. Knockdown of Twist or ITGB1 in BT549 and Hs578T cells decreased activity of FAK, ILK, and their downstream signaling, thus specifically impeding EMT and cell invasion. Knocking down ILK or inhibiting FAK, MAPK/ERK, or PI3K/AKT signaling also suppressed Twist-driven EMT and cell invasion. Thus, the Twist-ITGB1-FAK/ILK pathway and their downstream signaling network dictate the Twist-induced EMT process in human mammary epithelial cells and breast cancer cells. PMID:26693891

  20. Enhancement of mouse sperm motility by trophinin-binding peptide

    Directory of Open Access Journals (Sweden)

    Park Seong

    2012-11-01

    Full Text Available Abstract Background Trophinin is an intrinsic membrane protein that forms a complex in the cytoplasm with bystin and tastin, linking it microtubule-associated motor dynein (ATPase in some cell types. Previously, we found that human sperm tails contain trophinin, bystin and tastin proteins, and that trophinin-binding GWRQ (glycine, tryptophan, arginine, glutamine peptide enhanced motility of human sperm. Methods Immunohistochemistry was employed to determine trophinin protein in mouse spermatozoa from wild type mouse, by using spermatozoa from trophinin null mutant mice as a negative control. Multivalent 8-branched GWRQ (glycine, tryptophan, arginine, glutamine peptide or GWRQ-MAPS, was chemically synthesized, purified by HPLC and its structure was confirmed by MALDI-TOF mass spectrometry. Effect of GWRQ-MAPS on mouse spermatozoa from wild type and trophinin null mutant was assessed by a computer-assisted semen analyzer (CASA. Results Anti-trophinin antibody stained the principal (central piece of the tail of wild type mouse sperm, whereas the antibody showed no staining on trophinin null sperm. Phage particles displaying GWRQ bound to the principal piece of sperm tail from wild type but not trophinin null mice. GWRQ-MAPS enhanced motility of spermatozoa from wild type but not trophinin null mice. CASA showed that GWRQ-MAPS enhanced both progressive motility and rapid motility in wild type mouse sperm. Conclusions Present study established the expression of trophinin in the mouse sperm tail and trophinin-dependent effect of GWRQ-MAPS on sperm motility. GWRQ causes a significant increase in sperm motility.

  1. Persistence-driven durotaxis: Generic, directed motility in rigidity gradients

    CERN Document Server

    Novikova, Elizaveta A; Discher, Dennis E; Storm, Cornelis

    2015-01-01

    Cells move differently on substrates with different elasticities. In particular, the persistence time of their motion is higher on stiffer substrates. We show that this behavior will result in a net transport of cells directed up a soft-to-stiff gradient. Using simple random walk models with controlled persistence and stochastic simulations, we characterize this propensity to move in terms of the durotactic index measured in experiments. A one-dimensional model captures the essential features of this motion and highlights the competition between diffusive spreading and linear, wavelike propagation. Since the directed motion is rooted in a non-directional change in the behavior of individual cells, the motility is a kinesis rather than a taxis. Persistence-driven durokinesis is generic and may be of use in the design of instructive environments for cells and other motile, mechanosensitive objects.

  2. Motility in cyanobacteria: polysaccharide tracks and Type IV pilus motors.

    Science.gov (United States)

    Wilde, Annegret; Mullineaux, Conrad W

    2015-12-01

    Motility in cyanobacteria is useful for purposes that range from seeking out favourable light environments to establishing symbioses with plants and fungi. No known cyanobacterium is equipped with flagella, but a diverse range of species is able to 'glide' or 'twitch' across surfaces. Cyanobacteria with this capacity range from unicellular species to complex filamentous forms, including species such as Nostoc punctiforme, which can generate specialised motile filaments called hormogonia. Recent work on the model unicellular cyanobacterium Synechocystis sp. PCC 6803 has shown that its means of propulsion has much in common with the twitching motility of heterotrophs such as Pseudomonas and Myxococcus. Movement depends on Type IV pili, which are extended, adhere to the substrate and then retract to pull the cell across the surface. Previous work on filamentous cyanobacteria suggested a very different mechanism, with movement powered by the directional extrusion of polysaccharide from pores close to the cell junctions. Now a new report by Khayatan and colleagues in this issue of Molecular Microbiology suggests that the motility of Nostoc hormogonia has much more in common with Synechocystis than was previously thought. In both cases, polysaccharide secretion is important for preparing the surface, but the directional motive force comes from Type IV pili.

  3. Guanine Nucleotide-Binding Proteins of the G(12) Family Shape Immune Functions by Controlling CD4(+) T Cell Adhesiveness and Motility

    NARCIS (Netherlands)

    S. Herroeder; P. Reichardt; A. Sassmann; B. Zimmermann; D. Jaeneke; J. Hoeckner; M.W. Hollmann; K.D. Fischer; S. Vogt; R. Grosse; N. Hogg; M. Gunzer; S. Offermanns; N. Wettschureck

    2009-01-01

    Integrin-mediated adhesion plays a central role in T cell trafficking and activation. Genetic inactivation of the guanine nucleotide-binding (G) protein alpha-subunits G alpha(12) and G alpha(13) resulted in an increased activity of integrin leukocyte-function-antigen-1 in murine CD4(+) T cells. The

  4. A Novel High Content Imaging-Based Screen Identifies the Anti-Helminthic Niclosamide as an Inhibitor of Lysosome Anterograde Trafficking and Prostate Cancer Cell Invasion.

    Directory of Open Access Journals (Sweden)

    Magdalena L Circu

    Full Text Available Lysosome trafficking plays a significant role in tumor invasion, a key event for the development of metastasis. Previous studies from our laboratory have demonstrated that the anterograde (outward movement of lysosomes to the cell surface in response to certain tumor microenvironment stimulus, such as hepatocyte growth factor (HGF or acidic extracellular pH (pHe, increases cathepsin B secretion and tumor cell invasion. Anterograde lysosome trafficking depends on sodium-proton exchanger activity and can be reversed by blocking these ion pumps with Troglitazone or EIPA. Since these drugs cannot be advanced into the clinic due to toxicity, we have designed a high-content assay to discover drugs that block peripheral lysosome trafficking with the goal of identifying novel drugs that inhibit tumor cell invasion. An automated high-content imaging system (Cellomics was used to measure the position of lysosomes relative to the nucleus. Among a total of 2210 repurposed and natural product drugs screened, 18 "hits" were identified. One of the compounds identified as an anterograde lysosome trafficking inhibitor was niclosamide, a marketed human anti-helminthic drug. Further studies revealed that niclosamide blocked acidic pHe, HGF, and epidermal growth factor (EGF-induced anterograde lysosome redistribution, protease secretion, motility, and invasion of DU145 castrate resistant prostate cancer cells at clinically relevant concentrations. In an effort to identify the mechanism by which niclosamide prevented anterograde lysosome movement, we found that this drug exhibited no significant effect on the level of ATP, microtubules or actin filaments, and had minimal effect on the PI3K and MAPK pathways. Niclosamide collapsed intralysosomal pH without disruption of the lysosome membrane, while bafilomycin, an agent that impairs lysosome acidification, was also found to induce JLA in our model. Taken together, these data suggest that niclosamide promotes

  5. Screening of Compounds Toxicity against Human Monocytic cell line-THP-1 by Flow Cytometry

    Directory of Open Access Journals (Sweden)

    Pick Neora

    2004-01-01

    Full Text Available The worldwide rapid increase in bacterial resistance to numerous antibiotics requires on-going development of new drugs to enter the market. As the development of new antibiotics is lengthy and costly, early monitoring of compound's toxicity is essential in the development of novel agents. Our interest is in a rapid, simple, high throughput screening method to assess cytotoxicity induced by potential agents. Some intracellular pathogens, such as Mycobacterium tuberculosis primary site of infection is human alveolar macrophages. Thus, evaluation of candidate drugs for macrophage toxicity is crucial. Protocols for high throughput drug toxicity screening of macrophages using flow cytometry are lacking in the literature. For this application we modified a preexisting technique, propidium iodide (PI exclusion staining and utilized it for rapid toxicity tests. Samples were prepared in 96 well plates and analyzed by flow cytometry, which allowed for rapid, inexpensive and precise assessment of compound's toxicity associated with cell death.

  6. Liquid marbles for high-throughput biological screening of anchorage-dependent cells.

    Science.gov (United States)

    Oliveira, Nuno M; Correia, Clara R; Reis, Rui L; Mano, João F

    2015-01-28

    Stable liquid marbles (LM) are produced by coating liquid droplets with a hydrophobic powder. The used hydrophobic powder is produced by fluorosi-lanization of diatomaceous earth, used before to produce superhydrophobic structures. Here, the use of LM is proposed for high-throughput drug screening on anchorage-dependent cells. To provide the required cell adhesion sites inside the liquid environment of LM, surface-modified poly(l-lactic acid) microparticles are used. A simple method that takes advantage from LM appealing features is presented, such as the ability to inject liquid on LM without disrupting (self-healing ability), and to monitor color changes inside of LM. After promoting cell adhesion, a cytotoxic screening test is performed as a proof of concept. Fe(3+) is used as a model cytotoxic agent and is injected on LM. After incubation, AlamarBlue reagent is injected and used to assess the presence of viable cells, by monitoring color change from blue to red. Color intensity is measured by image processing and the analysis of pictures takes using an ordinary digital camera. The proposed method is fully validated in counterpoint to an MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carbo​xymethoxyphenyl)-2-(4-sulfophenyl)-2H-te​trazolium) colorimetric assay, a well-known method used for the cytotoxicity assessment.

  7. Silicon solar cells textured by reactive ion etching and processed with screen printing

    Energy Technology Data Exchange (ETDEWEB)

    Burgers, A.R.; Tool, C.J.J.; Hylton, J.D.; Weeber, A.W. [ECN Solar and Wind, Netherlands Energy Research Foundation ECN, Petten (Netherlands); Verholen, A.G.B.J.; Gardeniers, J.G.E.; De Boer, M.J.; Elwenspoek, M.C. [MESA Research Institute for Micro Electronics, Materials- and Molecular Engineering, and Sensors and Actuators, University of Twente, Enschede (Netherlands)

    1998-07-01

    Reactive Ion Etching (RIE) can texture multicrystalline silicon wafers very well. RIE has the advantage over alkaline etches that it is not sensitive to the crystallographic orientation. RIE has the advantage over acid etches that it can be controlled much better. This work describes multicrystalline silicon solar cells textured by RIE and processed with an industrial process sequence consisting of mainly screen-printing steps. We also made mini-modules of the RIE textured cells. The RIE texturing parameters can be varied to give different textures. Care must be taken that the texture is sufficiently rough to give a low encapsulated reflectance but not so rough that carriers generated by light absorbed in the texture recombine at the surface and cannot be collected at the p-n junction. The screen printing on RIE textured cells was successful. We were able to make cells with both low reflectance and good quantum efficiency. Due to encapsulation problems we were not able to demonstrate an efficiency gain yet. 10 refs.

  8. A cell-based screening system for anti-influenza A virus agents

    Science.gov (United States)

    Wong, Wan Ying; Loh, Sheng Wei; Ng, Wei Lun; Tan, Ming Cheang; Yeo, Kok Siong; Looi, Chung Yeng; Maah, Mohd Jamil; Ea, Chee-Kwee

    2015-01-01

    Emerging of drug resistant influenza A virus (IAV) has been a big challenge for anti-IAV therapy. In this study, we describe a relatively easy and safe cell-based screening system for anti-IAV replication inhibitors using a non-replicative strain of IAV. A nickel (II) complex of polyhydroxybenzaldehyde N4-thiosemicarbazone (NiPT5) was recently found to exhibit anti-inflammatory activity in vivo and in vitro. NiPT5 impedes the signaling cascades that lead to the activation of NF-κB in response to different stimuli, such as LPS and TNFα. Using our cell-based screening system, we report that pretreating cells with NiPT5 protects cells from influenza A virus (IAV) and vesicular stomatitis virus (VSV) infection. Furthermore, NiPT5 inhibits replication of IAV by inhibiting transcription and translation of vRNAs of IAV. Additionally, NiPT5 reduces IAV-induced type I interferon response and cytokines production. Moreover, NiPT5 prevents activation of NF-κB, and IRF3 in response to IAV infection. These results demonstrate that NiPT5 is a potent antiviral agent that inhibits the early phase of IAV replication. PMID:25728279

  9. BioSig3D: High Content Screening of Three-Dimensional Cell Culture Models.

    Directory of Open Access Journals (Sweden)

    Cemal Cagatay Bilgin

    Full Text Available BioSig3D is a computational platform for high-content screening of three-dimensional (3D cell culture models that are imaged in full 3D volume. It provides an end-to-end solution for designing high content screening assays, based on colony organization that is derived from segmentation of nuclei in each colony. BioSig3D also enables visualization of raw and processed 3D volumetric data for quality control, and integrates advanced bioinformatics analysis. The system consists of multiple computational and annotation modules that are coupled together with a strong use of controlled vocabularies to reduce ambiguities between different users. It is a web-based system that allows users to: design an experiment by defining experimental variables, upload a large set of volumetric images into the system, analyze and visualize the dataset, and either display computed indices as a heatmap, or phenotypic subtypes for heterogeneity analysis, or download computed indices for statistical analysis or integrative biology. BioSig3D has been used to profile baseline colony formations with two experiments: (i morphogenesis of a panel of human mammary epithelial cell lines (HMEC, and (ii heterogeneity in colony formation using an immortalized non-transformed cell line. These experiments reveal intrinsic growth properties of well-characterized cell lines that are routinely used for biological studies. BioSig3D is being released with seed datasets and video-based documentation.

  10. Fourier-transform infrared spectroscopy for rapid screening and live-cell monitoring: application to nanotoxicology

    Energy Technology Data Exchange (ETDEWEB)

    Sundaram, S. K.; Sacksteder, Colette A.; Weber, T. J.; Riley, Brian J.; Addleman, Raymond S.; Harrer, Bruce J.; Peterman, John W.

    2013-01-01

    A significant challenge to realize the full potential of nanotechnology for therapeutic and diagnostic applications is to understand and evaluate how live-cells interact with an external stimulus, e.g., a nanosized particle (NSP), and the toxicity and broad risk associated with these stimuli. NSPs are increasingly used in medicine with largely undetermined hazards in complex cell dynamics and environments. It is difficult to capture the complexity and dynamics of these interactions by following an omics-based approach exclusively, which are expensive and time-consuming. Additionally, this approach needs destructive sampling methods. Live-cell attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrometry is well suited to provide noninvasive approach to provide rapid screening of cellular responses to potentially toxic NSPs or any stimuli. Herein we review the technical basis of the approach, the instrument configuration and interface with the biological media, and various effects that impact the data, data analysis, and toxicity. Our preliminary results on live-cell monitoring show promise for rapid screening the NSPs.

  11. BioSig3D: High Content Screening of Three-Dimensional Cell Culture Models.

    Science.gov (United States)

    Bilgin, Cemal Cagatay; Fontenay, Gerald; Cheng, Qingsu; Chang, Hang; Han, Ju; Parvin, Bahram

    2016-01-01

    BioSig3D is a computational platform for high-content screening of three-dimensional (3D) cell culture models that are imaged in full 3D volume. It provides an end-to-end solution for designing high content screening assays, based on colony organization that is derived from segmentation of nuclei in each colony. BioSig3D also enables visualization of raw and processed 3D volumetric data for quality control, and integrates advanced bioinformatics analysis. The system consists of multiple computational and annotation modules that are coupled together with a strong use of controlled vocabularies to reduce ambiguities between different users. It is a web-based system that allows users to: design an experiment by defining experimental variables, upload a large set of volumetric images into the system, analyze and visualize the dataset, and either display computed indices as a heatmap, or phenotypic subtypes for heterogeneity analysis, or download computed indices for statistical analysis or integrative biology. BioSig3D has been used to profile baseline colony formations with two experiments: (i) morphogenesis of a panel of human mammary epithelial cell lines (HMEC), and (ii) heterogeneity in colony formation using an immortalized non-transformed cell line. These experiments reveal intrinsic growth properties of well-characterized cell lines that are routinely used for biological studies. BioSig3D is being released with seed datasets and video-based documentation. PMID:26978075

  12. Screening of Differently Expressed Genes in Human Prostate Cancer Cell Lines with Different Metastasis Potentials

    Institute of Scientific and Technical Information of China (English)

    SONG Anping; LIAO Guoning; WU Mingfu; LU Yunping; MA Ding

    2007-01-01

    In order to screen the genes differentially expressed in two human prostate cancer cells with different metastasis potentials, suppression subtractive hybridization (SSH) was done twice on human prostate cancer cell line with high potential of metastasis PC3M-1E8 and its synogenetic cell line PC3M-2B4 with low metastasis potential. In the first subtraction PC3M-2B4 was used as tester and PC3M-1E8 as driver and the forward subtractive library was constructed. In the second one the tester and driver were interchanged and the reverse subtractive library was constructed. The screened clones of both libraries were sequenced and Gene Bank homology search was performed. Some clones were confirmed by quantitative real-time PCR. The results showed that two subtrac-tive libraries containing 238 positive clones were constructed. Analysis of 16 sequenced clones ran-domly picked from two libraries showed that 4 differentially expressed gene fragments were identi-fied as new EST with unknown functions. It was concluded that two subtractive libraries of human prostate cancer cell lines with different metastasis potentials were constructed successfully.

  13. Identification of microprocessor-dependent cancer cells allows screening for growth-sustaining micro-RNAs.

    Science.gov (United States)

    Peric, D; Chvalova, K; Rousselet, G

    2012-04-19

    Micro-RNAs are deregulated in cancer cells, and some are either tumor suppressive or oncogenic. In addition, a link has been established between decreased expression of micro-RNAs and transformation, and several proteins of the RNA interference pathway have been shown to be haploinsufficient tumor suppressors. Oncogenic micro-RNAs (oncomiRs) could represent new therapeutic targets, and their identification is therefore crucial. However, structural and functional redundancy between micro-RNAs hampers approaches relying on individual micro-RNA inhibition. We reasoned that in cancer cells that depend on oncomiRs, impairing the micro-RNA pathway could lead to growth perturbation rather than increased tumorigenesis. Identifying such cells could allow functional analyses of individual micro-RNAs by complementation of the phenotypes observed upon global micro-RNA inhibition. Therefore, we developed episomal vectors coding for small hairpin RNAs targeting either Drosha or DGCR8, the two components of the microprocessor, the nuclear micro-RNA maturation complex. We identified cancer cell lines in which both vectors induced colony growth arrest. We then screened for individual micro-RNAs complementing this growth arrest, and identified miR-19a, miR-19b, miR-20a and miR-27b as major growth-sustaining micro-RNAs. However, the effect of miR-19a and miR-19b was only transient. In addition, embryonic stem cell-derived micro-RNAs with miR-20a seeds were much less efficient than miR-20a in sustaining cancer cell growth, a finding that contrasted with results obtained in stem cells. Finally, we showed that the tumor suppressor phosphatase and tensin homologue deleted on chromosome 10, a shared target of miR-19 and miR-20, was functionally involved in the growth arrest induced by microprocessor inhibition. We conclude that our approach allowed to identify microprocessor-dependent cancer cells, which could be used to screen for growth-sustaining micro-RNAs. This complementation screen

  14. Scintigraphic evaluation of gastrointestinal motility disorders

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Jae Gol [College of Medicine, Korea Univ., Seoul (Korea, Republic of)

    2001-02-01

    Current scintigraphic tests of gastrointestinal motor function provides relevant pathophysiologic information, but their clinical utility is controversial. Many scintigraphic methods are developed to investigate gastrointestinal motility from oral cavity to colon. These are esophageal transit scintigraphy, oropharyngeal transit study, gastric emptying test, small bowel transit time measurement, colon transit study and gastroesopahgeal reflux scintigraphy. Scintigraphy of gastrointestinal tract is the most physiologic and noninvasive method to evaluate gastrointestinal motility disorders. Stomach emptying test is regarded as a gold standard in motility study. Gastrointestinal transit scintigraphy also has a certain role in assessment of drug effect to GI motility and changes after theraphy of motility disorders. Scintigraphy provides noninvasive and quantitative assessment of physiological transit throughout the gastrointestinal tract, and it is extremely useful for diagnosing gastrointestinal motor dysfunction. This article reviews the current procedures, indications, significance and guidelines for gastrointestinal motility measurements by scintigraphy.

  15. Role of the Copper(II) Complex Cu[15]pyN5 in Intracellular ROS and Breast Cancer Cell Motility and Invasion.

    Science.gov (United States)

    Fernandes, Ana S; Flórido, Ana; Saraiva, Nuno; Cerqueira, Sara; Ramalhete, Sérgio; Cipriano, Madalena; Cabral, Maria Fátima; Miranda, Joana P; Castro, Matilde; Costa, Judite; Oliveira, Nuno G

    2015-10-01

    Multiple mechanisms related to metastases undergo redox regulation. Cu[15]pyN5 is a redox-active copper(II) complex previously studied as a chemotherapy sensitizer in mammary cells. The effects of a cotreatment with Cu[15]pyN5 and doxorubicin (dox) were evaluated in two human breast cancer cell lines: MCF7 (low aggressiveness) and MDA-MB-231 (highly aggressive). Cu[15]pyN5 decreased MCF7-directed cell migration. In addition, a cotreatment with dox and Cu[15]pyN5 reduced the proteolytic invasion of MDA-MB-231 cells. Cell detachment was not affected by exposure to these agents. Cu[15]pyN5 and dox significantly increased intracellular ROS in both cell lines. This increase could be at least partially due to H2 O2 accumulation. The combination of Cu[15]pyN5 with dox may be beneficial in breast cancer treatment as it could help reduce cancer cell migration and invasion. Moreover, the ligand [15]pyN5 has a high affinity for copper(II) and displays potential anti-angiogenic properties. Overall, we present a potential drug that might arrest the progression of breast cancer by different and complementary mechanisms.

  16. Establishment of a cell-based assay to screen regulators for Klotho gene promoter

    Institute of Scientific and Technical Information of China (English)

    Zhi-liang XU; Hong GAO; Ke-qing OU-YANG; Shao-xi CAI; Ying-he HU

    2004-01-01

    AIM: To discover compounds which can regulate Klotho promoter activity. Klotho is an aging suppressor gene. A defect in Klotho gene expression in the mouse results in the phenotype similar to human aging. Recombinant Klotho protein improves age-associated diseases in animal models. It has been proposed that up-regulation of Klotho gene expression may have anti-aging effects. METHODS: Klotho promoter was cloned into a vector containing luciferase gene, and the reporter gene vector was transfected into HEK293 cells to make a stable cell line (HEK293/KL). A model for cellular aging was established by treating HEK293/KL cells with H2O2. These cells were treated with extracts from Traditional Chinese Medicines (TCMs). The luciferase activity was detected to identify compounds that can regulate Klotho promoter. RESULTS:The expression of luciferase in these cells was under control of Klotho promoter and down-regulated after H2O2 treatment The down-regulation of luciferase expression was H2O2 concentration-dependent with an IC50 at approximately 0.006 %. This result demonstrated that the Klotho gene promoter was regulated by oxidative stress. Using the cell-based reporter gene assay, we screened natural product extracts for regulation of Klotho gene promoter. Several extracts were identified that could rescue the H2O2effects and up-regulated Klotho promoter activity. CONCLUSION: A cell -based assay for high-throughput drug screening was established to identify compounds that regulate Klotho promoter activity, and several hits were discovered from natural products. Further characterization of these active extracts could help to investigate Klotho function and aging mechanisms.

  17. Genome-wide RNAi Screen Identifies Networks Involved in Intestinal Stem Cell Regulation in Drosophila

    Directory of Open Access Journals (Sweden)

    Xiankun Zeng

    2015-02-01

    Full Text Available The intestinal epithelium is the most rapidly self-renewing tissue in adult animals and maintained by intestinal stem cells (ISCs in both Drosophila and mammals. To comprehensively identify genes and pathways that regulate ISC fates, we performed a genome-wide transgenic RNAi screen in adult Drosophila intestine and identified 405 genes that regulate ISC maintenance and lineage-specific differentiation. By integrating these genes into publicly available interaction databases, we further developed functional networks that regulate ISC self-renewal, ISC proliferation, ISC maintenance of diploid status, ISC survival, ISC-to-enterocyte (EC lineage differentiation, and ISC-to-enteroendocrine (EE lineage differentiation. By comparing regulators among ISCs, female germline stem cells, and neural stem cells, we found that factors related to basic stem cell cellular processes are commonly required in all stem cells, and stem-cell-specific, niche-related signals are required only in the unique stem cell type. Our findings provide valuable insights into stem cell maintenance and lineage-specific differentiation.

  18. MicroRNA-122 triggers mesenchymal-epithelial transition and suppresses hepatocellular carcinoma cell motility and invasion by targeting RhoA.

    Directory of Open Access Journals (Sweden)

    Sheng-Chun Wang

    Full Text Available The loss of microRNA-122 (miR-122 expression is strongly associated with increased invasion and metastasis, and poor prognosis of hepatocellular carcinoma (HCC, however, the underlying mechanisms remain poorly understood. In the present study, we observed that miR-122 over-expression in HCC cell lines Sk-hep-1 and Bel-7402 triggered the mesenchymal-epithelial transition (MET, as demonstrated by epithelial-like morphological changes, up-regulated epithelial proteins (E-cadherin, ZO-1, α-catenin, occludin, BVES, and MST4, and down-regulated mesenchymal proteins (vimentin and fibronectin. The over-expression of miRNA-122 also caused cytoskeleton disruption, RhoA/Rock pathway inactivation, enhanced cell adhesion, and suppression of migration and invasion of Sk-hep-1 and Bel-7402 cells, whereas, these effects could be reversed through miR-122 inhibition. Additional studies demonstrated that the inhibition of wild-type RhoA function induced MET and inhibited cell migration and invasion, while RhoA over-expression reversed miR-122-induced MET and inhibition of migration and invasion of HCC cells, suggesting that miR-122 induced MET and suppressed the migration and invasion of HCC cells by targeting RhoA. Moreover, our results demonstrated that HNF4α up-regulated its target gene miR-122 that subsequently induced MET and inhibited cell migration and invasion, whereas miR-122 inhibition reversed these HNF4α-induced phenotypes. These results revealed functional and mechanistic links among the tumor suppressors HNF4α, miR-122, and RhoA in EMT and invasive and metastatic phenotypes of HCC. Taken together, our study provides the first evidence that the HNF4α/miR-122/RhoA axis negatively regulates EMT and the migration and invasion of HCC cells.

  19. WNT signaling enhances breast cancer cell motility and blockade of the WNT pathway by sFRP1 suppresses MDA-MB-231 xenograft growth

    OpenAIRE

    Matsuda, Yutaka; Schlange, Thomas; Oakeley, Edward J.; Boulay, Anne; Nancy E Hynes

    2009-01-01

    Introduction In breast cancer, deregulation of the WNT signaling pathway occurs by autocrine mechanisms. WNT ligands and Frizzled receptors are coexpressed in primary breast tumors and cancer cell lines. Moreover, many breast tumors show hypermethylation of the secreted Frizzled-related protein 1 (sFRP1) promoter region, causing low expression of this WNT antagonist. We have previously shown that the WNT pathway influences proliferation of breast cancer cell lines via activation of canonical ...

  20. Versatile microscale screening platform for improving recombinant protein productivity in Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Hansen, Henning Gram; Nilsson, Claes Nymand; Lund, Anne Mathilde;

    2015-01-01

    to reduce production costs significantly. The aim of this study was to establish a versatile target gene screening platform for improving productivity for primarily non-mAb glycoproteins with complete interchangeability of model proteins and target genes using transient expression. The platform consists...... of four techniques compatible with 96-well microplates: lipid-based transient transfection, cell cultivation in microplates, cell counting and antibody-independent product titer determination based on split-GFP complementation. We were able to demonstrate growth profiles and volumetric productivity of CHO...... cells in 96-half-deepwell microplates comparable with those obtained in shake flasks. In addition, we demonstrate that split-GFP complementation can be used to accurately measure relative titers of therapeutic glycoproteins. Using this platform, we were able to detect target gene-specific increase...

  1. All Screen-Printed CdS/CuInSe2 Solar Cells

    Science.gov (United States)

    Kuhaimi, S. A. AL; Bahammam, S.

    1990-08-01

    Thick film technology offers advantages of low cost, product amenability and automation. This technology has been successful in the manufacture of solar cells using CdS/CdTe heterojunctions. It enables the use of the same equipment in various processes involved in manufacturing solar cells. In the present work, n-CdS/p-CuInSe2 solar cells are prepared by screen printing and sintering pastes which contain the semiconductors. An efficiency of 8.75% is achieved. Electron affinity difference, saturation current and diode quality factor are measured. They are 0.49 eV, (0.9--1.8)× 10-7 A, 1.5 respectively. Microstructure and electrical properties of sintered CdS films containing 10, 20, 30 and 40 wt% CdCl2 are investigated. Optimum results are obtained for the CdS films containing 10 wt% CdCl2.

  2. Automated cervical precancerous cells screening system based on Fourier transform infrared spectroscopy features

    Science.gov (United States)

    Jusman, Yessi; Mat Isa, Nor Ashidi; Ng, Siew-Cheok; Hasikin, Khairunnisa; Abu Osman, Noor Azuan

    2016-07-01

    Fourier transform infrared (FTIR) spectroscopy technique can detect the abnormality of a cervical cell that occurs before the morphological change could be observed under the light microscope as employed in conventional techniques. This paper presents developed features extraction for an automated screening system for cervical precancerous cell based on the FTIR spectroscopy as a second opinion to pathologists. The automated system generally consists of the developed features extraction and classification stages. Signal processing techniques are used in the features extraction stage. Then, discriminant analysis and principal component analysis are employed to select dominant features for the classification process. The datasets of the cervical precancerous cells obtained from the feature selection process are classified using a hybrid multilayered perceptron network. The proposed system achieved 92% accuracy.

  3. Does Hypothyroidism Affect Gastrointestinal Motility?

    Directory of Open Access Journals (Sweden)

    Olga Yaylali

    2009-01-01

    Full Text Available Background. Gastrointestinal motility and serum thyroid hormone levels are closely related. Our aim was to analyze whether there is a disorder in esophagogastric motor functions as a result of hypothyroidism. Materials and Methods. The study group included 30 females (mean age ± SE 45.17 ± 2.07 years with primary hypothyroidism and 10 healthy females (mean age ± SE 39.40 ± 3.95 years. All cases underwent esophagogastric endoscopy and scintigraphy. For esophageal scintigraphy, dynamic imaging of esophagus motility protocol, and for gastric emptying scintigraphy, anterior static gastric images were acquired. Results. The mean esophageal transit time (52.56 ± 4.07 sec for patients; 24.30 ± 5.88 sec for controls; P=.02 and gastric emptying time (49.06 ± 4.29 min for the hypothyroid group; 30.4 ± 4.74 min for the control group; P=.01 were markedly increased in cases of hypothyroidism. Conclusion. Hypothyroidism prominently reduces esophageal and gastric motor activity and can cause gastrointestinal dysfunction.

  4. Defective glycinergic synaptic transmission in zebrafish motility mutants

    Directory of Open Access Journals (Sweden)

    Hiromi Hirata

    2010-01-01

    Full Text Available Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem. Recently, in vivo analysis of glycinergic synaptic transmission has been pursued in zebrafish using molecular genetics. An ENU mutagenesis screen identified two behavioral mutants that are defective in glycinergic synaptic transmission. Zebrafish bandoneon (beo mutants have a defect in glrbb, one of the duplicated glycine receptor (GlyR β subunit genes. These mutants exhibit a loss of glycinergic synaptic transmission due to a lack of synaptic aggregation of GlyRs. Due to the consequent loss of reciprocal inhibition of motor circuits between the two sides of the spinal cord, motor neurons activate simultaneously on both sides resulting in bilateral contraction of axial muscles of beo mutants, eliciting the so-called ‘accordion’ phenotype. Similar defects in GlyR subunit genes have been observed in several mammals and are the basis for human hyperekplexia/startle disease. By contrast, zebrafish shocked (sho mutants have a defect in slc6a9, encoding GlyT1, a glycine transporter that is expressed by astroglial cells surrounding the glycinergic synapse in the hindbrain and spinal cord. GlyT1 mediates rapid uptake of glycine from the synaptic cleft, terminating synaptic transmission. In zebrafish sho mutants, there appears to be elevated extracellular glycine resulting in persistent inhibition of postsynaptic neurons and subsequent reduced motility, causing the ‘twitch once’ phenotype. We review current knowledge regarding zebrafish ‘accordion’ and ‘twitch once’ mutants, including beo and sho, and report the identification of a new α2 subunit that revises the phylogeny of zebrafish GlyRs.

  5. A chemical screen probing the relationship between mitochondrial content and cell size.

    Directory of Open Access Journals (Sweden)

    Toshimori Kitami

    Full Text Available The cellular content of mitochondria changes dynamically during development and in response to external stimuli, but the underlying mechanisms remain obscure. To systematically identify molecular probes and pathways that control mitochondrial abundance, we developed a high-throughput imaging assay that tracks both the per cell mitochondrial content and the cell size in confluent human umbilical vein endothelial cells. We screened 28,786 small molecules and observed that hundreds of small molecules are capable of increasing or decreasing the cellular content of mitochondria in a manner proportionate to cell size, revealing stereotyped control of these parameters. However, only a handful of compounds dissociate this relationship. We focus on one such compound, BRD6897, and demonstrate through secondary assays that it increases the cellular content of mitochondria as evidenced by fluorescence microscopy, mitochondrial protein content, and respiration, even after rigorous correction for cell size, cell volume, or total protein content. BRD6897 increases uncoupled respiration 1.6-fold in two different, non-dividing cell types. Based on electron microscopy, BRD6897 does not alter the percent of cytoplasmic area occupied by mitochondria, but instead, induces a striking increase in the electron density of existing mitochondria. The mechanism is independent of known transcriptional programs and is likely to be related to a blockade in the turnover of mitochondrial proteins. At present the molecular target of BRD6897 remains to be elucidated, but if identified, could reveal an important additional mechanism that governs mitochondrial biogenesis and turnover.

  6. Reverse MAPPIT: screening for protein-protein interaction modifiers in mammalian cells.

    Science.gov (United States)

    Eyckerman, Sven; Lemmens, Irma; Catteeuw, Dominiek; Verhee, Annick; Vandekerckhove, Joel; Lievens, Sam; Tavernier, Jan

    2005-06-01

    Interactions between proteins are at the heart of the cellular machinery. It is therefore not surprising that altered interaction profiles caused by aberrant protein expression patterns or by the presence of mutations can trigger cellular dysfunction, eventually leading to disease. Moreover, many viral and bacterial pathogens rely on protein-protein interactions to exert their damaging effects. Interfering with such interactions is an obvious pharmaceutical goal, but detailed insights into the protein binding properties as well as efficient screening platforms are needed. In this report, we describe a cytokine receptor-based assay with a positive readout to screen for disrupters of designated protein-protein interactions in intact mammalian cells and evaluate this concept using polypeptides as well as small organic molecules. These reverse mammalian protein-protein interaction trap (MAPPIT) screens were developed to monitor interactions between the erythropoietin receptor (EpoR) and suppressors of cytokine signaling (SOCS) proteins, between FKBP12 and ALK4, and between MDM2 and p53. PMID:15908921

  7. A cell-free microtiter plate screen for improved [FeFe] hydrogenases.

    Directory of Open Access Journals (Sweden)

    James A Stapleton

    Full Text Available BACKGROUND: [FeFe] hydrogenase enzymes catalyze the production and dissociation of H(2, a potential renewable fuel. Attempts to exploit these catalysts in engineered systems have been hindered by the biotechnologically inconvenient properties of the natural enzymes, including their extreme oxygen sensitivity. Directed evolution has been used to improve the characteristics of a range of natural catalysts, but has been largely unsuccessful for [FeFe] hydrogenases because of a lack of convenient screening platforms. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe an in vitro screening technology for oxygen-tolerant and highly active [FeFe] hydrogenases. Despite the complexity of the protocol, we demonstrate a level of reproducibility that allows moderately improved mutants to be isolated. We have used the platform to identify a mutant of the Chlamydomonas reinhardtii [FeFe] hydrogenase HydA1 with a specific activity approximately 4 times that of the wild-type enzyme. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate the feasibility of using the screen presented here for large-scale efforts to identify improved biocatalysts for energy applications. The system is based on our ability to activate these complex enzymes in E. coli cell extracts, which allows unhindered access to the protein maturation and assay environment.

  8. A Cell-based High-throughput Screening Assay for Farnesoid X Recepter Agonist

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To develop a high-throughput screening assay for Farnesoid X receptor (FXR) agonists based on mammalian one-hybrid system (a chimera receptor gene system) for the purpose of identifying new lead compounds for dyslipidaemia drug from the chemical library. Methods cDNA encoding the human FXR ligand binding domain (LBD) was amplified by RT-PCR from a human liver total mRNA and fused to the DNA binding domain (DBD) of yeast GAL4 of pBIND to construct a GAL4-FXR (LBD) chimera expression plasmid. Five copies of the GAL4 DNA binding site were synthesized and inserted into upstream of the SV40 promoter of pGL3-promoter vector to construct a reporter plasmid pG5-SV40 Luc. The assay was developed by transient co-transfection with pG5-SV40 Luc reporter plasmid and pBIND-FXR-LBD (189-472) chimera expression plasmid. Results After optimization, CDCA, a FXR natural agonist, could induce expression of the luciferase gene in a dose-dependent manner, and had a signal/noise ratio of 10 and Z'factor value of 0.65. Conclusion A stable and sensitive cell-based high-throughput screening model can be used in high-throughput screening for FXR agonists from the synthetic and natural compound library.

  9. Galectin-3 facilitates cell motility in gastric cancer by up-regulating protease-activated receptor-1 (PAR-1 and matrix metalloproteinase-1 (MMP-1.

    Directory of Open Access Journals (Sweden)

    Seok-Jun Kim

    Full Text Available BACKGROUND: Galectin-3 is known to regulate cancer metastasis. However, the underlying mechanism has not been defined. Through the DNA microarray studies after galectin-3 silencing, we demonstrated here that galectin-3 plays a key role in up-regulating the expressions of protease-activated receptor-1 (PAR-1 and matrix metalloproteinase-1 (MMP-1 PAR-1 thereby promoting gastric cancer metastasis. METHODOLOGY/PRINCIPAL FINDINGS: We examined the expression levels of Galectin-3, PAR-1, and MMP-1 in gastric cancer patient tissues and also the effects of silencing these proteins with specific siRNAs and of over-expressing them using specific lenti-viral constructs. We also employed zebrafish embryo model for analysis of in vivo gastric cancer cell invasion. These studies demonstrated that: a galectin-3 silencing decreases the expression of PAR-1. b galectin-3 over-expression increases cell migration and invasion and this increase can be reversed by PAR-1 silencing, indicating that galectin-3 increases cell migration and invasion via PAR-1 up-regulation. c galectin-3 directly interacts with AP-1 transcriptional factor, and this complex binds to PAR-1 promoter and drives PAR-1 transcription. d galectin-3 also amplifies phospho-paxillin, a PAR-1 downstream target, by increasing MMP-1 expression. MMP-1 silencing blocks phospho-paxillin amplification and cell invasion caused by galectin-3 over-expression. e Silencing of either galectin-3, PAR-1 or MMP-1 significantly reduced cell migration into the vessels in zebrafish embryo model. f Galectin-3, PAR-1, and MMP-1 are highly expressed and co-localized in malignant tissues from gastric cancer patients. CONCLUSIONS/SIGNIFICANCE: Galectin-3 plays the key role of activating cell surface receptor through production of protease and boosts gastric cancer metastasis. Galectin-3 has the potential to serve as a useful pharmacological target for prevention of gastric cancer metastasis.

  10. Design and screening of a glial cell-specific, cell penetrating peptide for therapeutic applications in multiple sclerosis.

    Directory of Open Access Journals (Sweden)

    Corey Heffernan

    Full Text Available Multiple Sclerosis (MS is an autoimmune, neurodegenerative disease of the central nervous system (CNS characterized by demyelination through glial cell loss. Current and proposed therapeutic strategies to arrest demyelination and/or promote further remyelination include: (i modulation of the host immune system; and/or (ii transplantation of myelinating/stem or progenitor cells to the circulation or sites of injury. However, significant drawbacks are inherent with both approaches. Cell penetrating peptides (CPP are short amino acid sequences with an intrinsic ability to translocate across plasma membranes, and theoretically represent an attractive vector for delivery of therapeutic peptides or nanoparticles to glia to promote cell survival or remyelination. The CPPs described to date are commonly non-selective in the cell types they transduce, limiting their therapeutic application in vivo. Here, we describe a theoretical framework for design of a novel CPP sequence that selectively transduces human glial cells (excluding non-glial cell types, and conduct preliminary screens of purified, recombinant CPPs with immature and matured human oligodendrocytes and astrocytes, and two non-glial cell types. A candidate peptide, termed TD2.2, consistently transduced glial cells, was significantly more effective at transducing immature oligodendrocytes than matured progeny, and was virtually incapable of transducing two non-glial cell types: (i human neural cells and (ii human dermal fibroblasts. Time-lapse confocal microscopy confirms trafficking of TD2.2 (fused to EGFP to mature oligodendrocytes 3-6 hours after protein application in vitro. We propose selectivity of TD2.2 for glial cells represents a new therapeutic strategy for the treatment of glial-related disease, such as MS.

  11. Preliminary screening and identification of stem cell-like sphere clones in a gallbladder cancer cell line GBC-SD*

    Institute of Scientific and Technical Information of China (English)

    Bao-bing YIN; Shuang-jie WU; Hua-jie ZONG; Bao-jin MA; Duan CAI

    2011-01-01

    This paper aims to screen and identify sphere clone cells with characteristics similar to cancer stem cellsin human gallbladder cancer cell line GBC-SD. GBC-SD cells were cultured in a serum-free culture medium with different concentrations of the chemotherapeutic drug cisplatin for generating sphere clones. The mRNA expressions of stem cell-related genes CD133, OCT-4, Nanog, and drug resistance genes ABCG2 and MDR-1 in sphere clones were detected by quantitative real-time polymerase chain reaction (PCR). Stem cell markers were also analyzed by flow cytometry and immunofluorescent staining. Different amounts of sphere clones were injected into nude mice to test their abilities to form tumors. Sphere clones were formed in serum-free culture medium containing cisplatin (30 pmol/L).Flow cytometry results demonstrated that the sphere clones expressed high levels of stem cell markers CD133+ (97.6%) and CD44+ (77.9%) and low levels of CD24+ (2.3%). These clones also overexpressed the drug resistance genes ABCG2 and MDR-1. Quantitative real-time PCR showed that sphere clones expressed stem cell genes Nanog and OCT-4 284 and 266 times, respectively, more than those in the original GBC-SD cells. Immunofluorescent staining showed that sphere clones overexpressed OCT-4, Nanog, and SOX-2, and Iow expressed MUG1 and vimentin. Tumor formation experiments showed that 1 x 103 sphere clone cells could induce much larger tumors in nude mice than 1 x 105 GBC-SD cells. In conclusion, sphere clones of gallbladder cancer with stem cell-like characteristics can be obtained using suspension cultures of GBC-SD cells in serum-free culture medium containing cisplatin.

  12. Screen for localized proteins in Caulobacter crescentus.

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    Jay H Russell

    Full Text Available Precise localization of individual proteins is required for processes such as motility, chemotaxis, cell-cycle progression, and cell division in bacteria, but the number of proteins that are localized in bacterial species is not known. A screen based on transposon mutagenesis and fluorescence activated cell sorting was devised to identify large numbers of localized proteins, and employed in Caulobacter crescentus. From a sample of the clones isolated in the screen, eleven proteins with no previously characterized localization in C. crescentus were identified, including six hypothetical proteins. The localized hypothetical proteins included one protein that was localized in a helix-like structure, and two proteins for which the localization changed as a function of the cell cycle, suggesting that complex three-dimensional patterns and cell cycle-dependent localization are likely to be common in bacteria. Other mutants produced localized fusion proteins even though the transposon has inserted near the 5' end of a gene, demonstrating that short peptides can contain sufficient information to localize bacterial proteins. The screen described here could be used in most bacterial species.

  13. web cellHTS2: A web-application for the analysis of high-throughput screening data

    Directory of Open Access Journals (Sweden)

    Boutros Michael

    2010-04-01

    Full Text Available Abstract Background The analysis of high-throughput screening data sets is an expanding field in bioinformatics. High-throughput screens by RNAi generate large primary data sets which need to be analyzed and annotated to identify relevant phenotypic hits. Large-scale RNAi screens are frequently used to identify novel factors that influence a broad range of cellular processes, including signaling pathway activity, cell proliferation, and host cell infection. Here, we present a web-based application utility for the end-to-end analysis of large cell-based screening experiments by cellHTS2. Results The software guides the user through the configuration steps that are required for the analysis of single or multi-channel experiments. The web-application provides options for various standardization and normalization methods, annotation of data sets and a comprehensive HTML report of the screening data analysis, including a ranked hit list. Sessions can be saved and restored for later re-analysis. The web frontend for the cellHTS2 R/Bioconductor package interacts with it through an R-server implementation that enables highly parallel analysis of screening data sets. web cellHTS2 further provides a file import and configuration module for common file formats. Conclusions The implemented web-application facilitates the analysis of high-throughput data sets and provides a user-friendly interface. web cellHTS2 is accessible online at http://web-cellHTS2.dkfz.de. A standalone version as a virtual appliance and source code for platforms supporting Java 1.5.0 can be downloaded from the web cellHTS2 page. web cellHTS2 is freely distributed under GPL.

  14. Genistein Increase Intracellular Distribution of the High Motility Group Box - 1 through p38 Pathway in HeLa culture cells induced by Tumor Necrosis Factor - α

    Directory of Open Access Journals (Sweden)

    Merlita Herbani

    2014-05-01

    Full Text Available Cervical cancer is one kind of many cancers that cause death to women around the world. Many studies had support the statement that inflammation has a strong linkage with cancer development. Several factors like proinflammatory factor can influence tumor cell microenvironment, and induce a faster proliferation. TNF-α is suspected can induce proliferation. While cancer itself can induce inflammation, which is marked by several marker. One of them is HMGB1, released from the cell as active secretory lysosomes or passive diffusion. Genistein has demonstrated growth inhibitory effects of various types of cancer cells. It inhibits tyrosine kinase pathway, which can be activated by TNF-α. One of those pathways that have the link with proliferation is p38. This study tries to reveal about inhibitory effect of genistein toward p38 pathway that had been activated by TNF-α. This research was conducted by exposing cultured HeLa cells with various doses of genistein for 90 minutes, and then exposed to TNF-α 10 ng / mL for 20 minutes. Observations were made with a confocal microscope, by staining the cells with pp38-TRITC and HMGB1 antibody. The intensity was measured and analyzed by Fluoview software. The results suggest that there be significant differences between pp38 intranuclear intensity and HMGB1 extranuclear intensity of each dose of genistein (p = 0.000, ANOVA. pp38 and HMGB1 intensity were increased along with increasing genistein dose, but at high dose there were noted decreasing of pp38 and HMGB1 intensity. At apoptotic dose, pp38 and HMGB1 intensity were increased markedly, showing the effect of apoptosis. In general, increasing doses of genistein increase intranuclear p38 activation and HMGB1 extranuclear translocation. So there were a strong linkage between p38 activation and HMGB1 translocation in this study.

  15. A loss-of-function genetic screening identifies novel mediators of thyroid cancer cell viability

    Science.gov (United States)

    Cantisani, Maria Carmela; Parascandolo, Alessia; Perälä, Merja; Allocca, Chiara; Fey, Vidal; Sahlberg, Niko; Merolla, Francesco; Basolo, Fulvio; Laukkanen, Mikko O.; Kallioniemi, Olli Pekka; Santoro, Massimo; Castellone, Maria Domenica

    2016-01-01

    RET, BRAF and other protein kinases have been identified as major molecular players in thyroid cancer. To identify novel kinases required for the viability of thyroid carcinoma cells, we performed a RNA interference screening in the RET/PTC1(CCDC6-RET)-positive papillary thyroid cancer cell line TPC1 using a library of synthetic small interfering RNAs (siRNAs) targeting the human kinome and related proteins. We identified 14 hits whose silencing was able to significantly reduce the viability and the proliferation of TPC1 cells; most of them were active also in BRAF-mutant BCPAP (papillary thyroid cancer) and 8505C (anaplastic thyroid cancer) and in RAS-mutant CAL62 (anaplastic thyroid cancer) cells. These included members of EPH receptor tyrosine kinase family as well as SRC and MAPK (mitogen activated protein kinases) families. Importantly, silencing of the identified hits did not affect significantly the viability of Nthy-ori 3-1 (hereafter referred to as NTHY) cells derived from normal thyroid tissue, suggesting cancer cell specificity. The identified proteins are worth exploring as potential novel druggable thyroid cancer targets. PMID:27058903

  16. MOCVD ZnO/Screen Printed Ag Back Reflector for Flexible Thin Film Silicon Solar Cell Application

    Directory of Open Access Journals (Sweden)

    Amornrat Limmanee

    2014-01-01

    Full Text Available We have prepared Ag back electrode by screen printing technique and developed MOCVD ZnO/screen printed Ag back reflector for flexible thin film silicon solar cell application. A discontinuity and poor contact interface between the MOCVD ZnO and screen printed Ag layers caused poor open circuit voltage (Voc and low fill factor (FF; however, an insertion of a thin sputtered ZnO layer at the interface could solve this problem. The n type hydrogenated amorphous silicon (a-Si:H film is preferable for the deposition on the surface of MOCVD ZnO film rather than the microcrystalline film due to its less sensitivity to textured surface, and this allowed an improvement in the FF. The n-i-p flexible amorphous silicon solar cell using the MOCVD ZnO/screen printed Ag back reflector showed an initial efficiency of 6.2% with Voc=0.86 V, Jsc=12.4 mA/cm2, and FF = 0.58 (1 cm2. The identical quantum efficiency and comparable performance to the cells using conventional sputtered Ag back electrode have verified the potential of the MOCVD ZnO/screen printed Ag back reflector and possible opportunity to use the screen printed Ag thick film for flexible thin film silicon solar cells.

  17. Combinatorial synthesis and screening of cancer cell-specific nanomedicines targeted via phage fusion proteins

    Directory of Open Access Journals (Sweden)

    James W. Gillespie

    2015-06-01

    Full Text Available Active tumor targeting of nanomedicines has recently shown significant improvements in the therapeutic activity of currently existing drug delivery systems, such as liposomal doxorubicin (Doxil/Caelyx/Lipodox. Previously, we have shown that isolated pVIII major coat proteins of the fd tet filamentous phage vector, containing cancer cell-specific peptide fusions at their N terminus, can be used as active targeting ligands in a liposomal doxorubicin delivery system in vitro and in vivo. Here, we show a novel major coat protein isolation procedure in 2-propanol that allows spontaneous incorporation of the hydrophobic protein core into preformed liposomal doxorubicin with minimal damage or drug loss while still retaining the targeting ligand exposed for cell-specific targeting. Using a panel of 12 structurally unique ligands with specificity towards breast, lung, and/or pancreatic cancer, we showed the feasibility of pVIII major coat proteins to significantly increase the throughput of targeting ligand screening in a common nanomedicine core. Phage protein-modified Lipodox samples showed an average doxorubicin recovery of 82.8% across all samples with 100% of protein incorporation in the correct orientation (N-terminus exposed. Following cytotoxicity screening in a doxorubicin-sensitive breast cancer line (MCF-7, three major groups of ligands were identified. Ligands showing the most improved cytotoxicity included: DMPGTVLP, ANGRPSMT, VNGRAEAP, and ANDVYLD showing a 25-fold improvement (p < 0.05 in toxicity. Similarly DGQYLGSQ, ETYNQPYL, and GSSEQLYL ligands with specificity towards a doxorubicin-insensitive pancreatic cancer line (PANC-1 showed significant increases in toxicity (2-fold; p < 0.05. Thus, we demonstrated proof-of-concept that pVIII major coat proteins can be screened in significantly higher throughput to identify novel ligands displaying improved therapeutic activity in a desired cancer phenotype.

  18. Investigation of motility and biofilm formation by intestinal Campylobacter concisus strains

    Directory of Open Access Journals (Sweden)

    Lavrencic Peter

    2012-12-01

    Full Text Available Abstract Motility helps many pathogens swim through the highly viscous intestinal mucus. Given the differing outcomes of Campylobacter concisus infection, the motility of eight C. concisus strains isolated from patients with Crohn’s disease (n=3, acute (n=3 and chronic (n=1 gastroenteritis and a healthy control (n=1 were compared. Following growth on solid or liquid media the eight strains formed two groups; however, the type of growth medium did not affect motility. In contrast, following growth in viscous liquid medium seven of the eight strains demonstrated significantly decreased motility. In media of increasing viscosities the motility of C. concisus UNSWCD had two marked increases at viscosities of 20.0 and 74.7 centipoises. Determination of the ability of UNSWCD to swim through a viscous medium, adhere to and invade intestinal epithelial cells showed that while adherence levels significantly decreased with increasing viscosity, invasion levels did not significantly change. In contrast, adherence to and invasion of UNSWCD to mucus-producing intestinal cells increased upon accumulation of mucus, as did bacterial aggregation. Given this aggregation, we determined the ability of the eight C. concisus strains to form biofilms, and showed that all strains formed biofilms. In conclusion, the finding that C. concisus strains could be differentiated into two groups based on their motility may suggest that strains with high motility have an increased ability to swim through the intestinal mucus and reach the epithelial layer.

  19. The Actin Filament-Binding Protein Coronin Regulates Motility in Plasmodium Sporozoites

    Science.gov (United States)

    Bane, Kartik S.; Singer, Mirko; Reinig, Miriam; Klug, Dennis; Heiss, Kirsten; Baum, Jake; Mueller, Ann-Kristin; Frischknecht, Friedrich

    2016-01-01

    Parasites causing malaria need to migrate in order to penetrate tissue barriers and enter host cells. Here we show that the actin filament-binding protein coronin regulates gliding motility in Plasmodium berghei sporozoites, the highly motile forms of a rodent malaria-causing parasite transmitted by mosquitoes. Parasites lacking coronin show motility defects that impair colonization of the mosquito salivary glands but not migration in the skin, yet result in decreased transmission efficiency. In non-motile sporozoites low calcium concentrations mediate actin-independent coronin localization to the periphery. Engagement of extracellular ligands triggers an intracellular calcium release followed by the actin-dependent relocalization of coronin to the rear and initiation of motility. Mutational analysis and imaging suggest that coronin organizes actin filaments for productive motility. Using coronin-mCherry as a marker for the presence of actin filaments we found that protein kinase A contributes to actin filament disassembly. We finally speculate that calcium and cAMP-mediated signaling regulate a switch from rapid parasite motility to host cell invasion by differentially influencing actin dynamics. PMID:27409081

  20. Gaslike model of social motility

    CERN Document Server

    Parravano, A; 10.1103/PhysRevE.78.026120

    2009-01-01

    We propose a model to represent the motility of social elements. The model is completely deterministic, possesses a small number of parameters, and exhibits a series of properties that are reminiscent of the behavior of comunities in social-ecological competition; these are: (i) similar individuals attract each other; (ii) individuals can form stable groups; (iii) a group of similar individuals breaks into subgroups if it reaches a critical size; (iv) interaction between groups can modify the distribution of the elements as a result of fusion, fission, or pursuit; (v) individuals can change their internal state by interaction with their neighbors. The simplicity of the model and its richness of emergent behaviors, such as, for example, pursuit between groups, make it a useful toy model to explore a diversity of situations by changing the rule by which the internal state of individuals is modified by the interactions with the environment.

  1. Towards a full karyotype screening of interphase cells: 'FISH and chip' technology

    Energy Technology Data Exchange (ETDEWEB)

    Weier, Heinz-Ulli G.; Munne, Santiago; Lersch, Robert A.; Hsieh, H.-Ben; Smida, Jan; Chen, Xiao-Ning; Korenberg, Julie R.; Pedersen, Roger A.; Fung, Jingley

    2003-06-23

    Numerical chromosome aberrations are incompatible with normal human development. Our laboratories develop hybridization based screening tools that generate a maximum of cytogenetic information for each polar body or blastomere analyzed. The methods are developed considering that the abnormality might require preparation of case-specific probes and that only one or two cells will be available for diagnosis, most of which might be in the interphase stage. Further more, assay efficiencies have to be high, since there is typically not enough time to repeat an experiment or reconfirm a result prior to fertilization or embryo transfer. Structural alterations are delineated with break point-spanning probes. When screening for numerical abnormalities, we apply a Spectral Imaging-based approach to simultaneously score as many as ten different chromosome types in individual inter phase cells. Finally, DNA micro-arrays are under development to score all of the human chromosomes in a single experiment and to increase the resolution with which micro-deletions can be delineated.

  2. High-Throughput Screening and Optimization of Binary Quantum Dots Cosensitized Solar Cell.

    Science.gov (United States)

    Yuan, Ding; Xiao, Lina; Luo, Jianheng; Luo, Yanhong; Meng, Qingbo; Mao, Bing-Wei; Zhan, Dongping

    2016-07-20

    Quantum dots (QDs) are considered as the alternative of dye sensitizers for solar cells. However, interfacial construction and evaluation of photocatalytic nanomaterials still remains challenge through the conventional methodology involving demo devices. We propose here a high-throughput screening and optimizing method based on combinatorial chemistry and scanning electrochemical microscopy (SECM). A homogeneous TiO2 catalyst layer is coated on a FTO substrate, which is then covered by a dark mask to expose the photocatalyst array. On each photocatalyst spot, different successive ionic layer adsorption and reaction (SILAR) processes are performed by a programmed solution dispenser to load the binary PbxCd1-xS QDs sensitizers. An optical fiber is employed as the scanning tip of SECM, and the photocatalytic current is recorded during the imaging experiment, through which the optimized technical parameters are figured out. To verify the validity of the combinatorial SECM imaging results, the controlled trials are performed with the corresponding photovoltaic demo devices. The harmonious accordance proved that the methodology based on combinatorial chemistry and SECM is valuable for the interfacial construction, high-throughput screening, and optimization of QDSSCs. Furthermore, the PbxCd1-xS/CdS QDs cosensitized solar cell optimized by SECM achieves a short circuit current density of 24.47 mA/cm(2), an open circuit potential of 421 mV, a fill factor of 0.52, and a photovoltaic conversion efficiency of 5.33%. PMID:27355523

  3. [Embryonic stem cell test in screening of medicine and other chemicals].

    Science.gov (United States)

    Zhao, Qing; Xu, Jinsen

    2005-02-01

    The technique of embryonic stem cell test (EST) has been developed and used in vitro to screen new medicines and other chemicals. According to toxicity, such medicines and chemicals can be classified as: non-toxic, weak toxic and/or strong toxic. EST shows merits such as no requirement of the sacrifice of pregnant animals, no side-effects on human or animals for candidate medicines and chemicals, higher sensitivity of embryonic stem cells when compared with the sensitivity of ordinary tissues of adult samples in toxicologic researches, higher accuracy when combined with computing techniques, and possible quantitation based on techniques of molecular biology. Advances in utility of EST technique were reviewed and the prospect of technique was also discussed in this paper. PMID:15762145

  4. Curvature-guided motility of microalgae in geometric confinement

    CERN Document Server

    Ostapenko, Tanya; Böddeker, Thomas; Kreis, Christian; Cammann, Jan; Mazza, Marco G; Bäumchen, Oliver

    2016-01-01

    Microorganisms often live in microhabitats that consist of a liquid phase and a plethora of typically curved interfaces. The ways in which motile cells possessing propulsive appendages sense and interact with the physical nature of their environment remains unclear today. For pusher-type microswimmers with rear-mounted flagella, such as bacteria and spermatozoa, cell trapping at a wall was attributed to contrasting microscopic mechanisms, namely hydrodynamic and contact interactions. Here, we demonstrate that, in confined spaces, the geometry of the habitat controls the motility of microalgae that propel themselves by the beating of two anterior flagella. Brownian dynamics simulations and analytical theory both quantitatively match the experimental data and capture a characteristic curvature scaling observed in the experiments. This curvature-guided navigation of the microalgae originates from only two essential ingredients: excluded volume resulting in predominantly ballistic swimming in confinement and the ...

  5. NZ51, a ring-expanded nucleoside analog, inhibits motility and viability of breast cancer cells by targeting the RNA helicase DDX3

    OpenAIRE

    Xie, Min; Vesuna, Farhad; Botlagunta, Mahendran; Bol, Guus Martinus; Irving, Ashley; Bergman, Yehudit; Hosmane, Ramachandra S.; Kato, Yoshinori; Winnard, Paul T.; Raman, Venu

    2015-01-01

    DDX3X (DDX3), a human RNA helicase, is over expressed in multiple breast cancer cell lines and its expression levels are directly correlated to cellular aggressiveness. NZ51, a ring-expanded nucleoside analogue (REN) has been reported to inhibit the ATP dependent helicase activity of DDX3. Molecular modeling of NZ51 binding to DDX3 indicated that the 5:7-fused imidazodiazepine ring of NZ51 was incorporated into the ATP binding pocket of DDX3. In this study, we investigated the anticancer prop...

  6. Engineering cell-compatible paper chips for cell culturing, drug screening, and mass spectrometric sensing.

    Science.gov (United States)

    Chen, Qiushui; He, Ziyi; Liu, Wu; Lin, Xuexia; Wu, Jing; Li, Haifang; Lin, Jin-Ming

    2015-10-28

    Paper-supported cell culture is an unprecedented development for advanced bioassays. This study reports a strategy for in vitro engineering of cell-compatible paper chips that allow for adherent cell culture, quantitative assessment of drug efficiency, and label-free sensing of intracellular molecules via paper spray mass spectrometry. The polycarbonate paper is employed as an excellent alternative bioscaffold for cell distribution, adhesion, and growth, as well as allowing for fluorescence imaging without light scattering. The cell-cultured paper chips are thus amenable to fabricate 3D tissue construction and cocultures by flexible deformation, stacks and assembly by layers of cells. As a result, the successful development of cell-compatible paper chips subsequently offers a uniquely flexible approach for in situ sensing of live cell components by paper spray mass spectrometry, allowing profiling the cellular lipids and quantitative measurement of drug metabolism with minimum sample pretreatment. Consequently, the developed paper chips for adherent cell culture are inexpensive for one-time use, compatible with high throughputs, and amenable to label-free and rapid analysis.

  7. Disruption of TgPHIL1 alters specific parameters of Toxoplasma gondii motility measured in a quantitative, three-dimensional live motility assay.

    Directory of Open Access Journals (Sweden)

    Jacqueline M Leung

    Full Text Available T. gondii uses substrate-dependent gliding motility to invade cells of its hosts, egress from these cells at the end of its lytic cycle and disseminate through the host organism during infection. The ability of the parasite to move is therefore critical for its virulence. T. gondii engages in three distinct types of gliding motility on coated two-dimensional surfaces: twirling, circular gliding and helical gliding. We show here that motility in a three-dimensional Matrigel-based environment is strikingly different, in that all parasites move in irregular corkscrew-like trajectories. Methods developed for quantitative analysis of motility parameters along the smoothed trajectories demonstrate a complex but periodic pattern of motility with mean and maximum velocities of 0.58 ± 0.07 µm/s and 2.01 ± 0.17 µm/s, respectively. To test how a change in the parasite's crescent shape might affect trajectory parameters, we compared the motility of Δphil1 parasites, which are shorter and wider than wild type, to the corresponding parental and complemented lines. Although comparable percentages of parasites were moving for all three lines, the Δphil1 mutant exhibited significantly decreased trajectory lengths and mean and maximum velocities compared to the parental parasite line. These effects were either partially or fully restored upon complementation of the Δphil1 mutant. These results show that alterations in morphology may have a significant impact on T. gondii motility in an extracellular matrix-like environment, provide a possible explanation for the decreased fitness of Δphil1 parasites in vivo, and demonstrate the utility of the quantitative three-dimensional assay for studying parasite motility.

  8. Disruption of TgPHIL1 alters specific parameters of Toxoplasma gondii motility measured in a quantitative, three-dimensional live motility assay.

    Science.gov (United States)

    Leung, Jacqueline M; Rould, Mark A; Konradt, Christoph; Hunter, Christopher A; Ward, Gary E

    2014-01-01

    T. gondii uses substrate-dependent gliding motility to invade cells of its hosts, egress from these cells at the end of its lytic cycle and disseminate through the host organism during infection. The ability of the parasite to move is therefore critical for its virulence. T. gondii engages in three distinct types of gliding motility on coated two-dimensional surfaces: twirling, circular gliding and helical gliding. We show here that motility in a three-dimensional Matrigel-based environment is strikingly different, in that all parasites move in irregular corkscrew-like trajectories. Methods developed for quantitative analysis of motility parameters along the smoothed trajectories demonstrate a complex but periodic pattern of motility with mean and maximum velocities of 0.58 ± 0.07 µm/s and 2.01 ± 0.17 µm/s, respectively. To test how a change in the parasite's crescent shape might affect trajectory parameters, we compared the motility of Δphil1 parasites, which are shorter and wider than wild type, to the corresponding parental and complemented lines. Although comparable percentages of parasites were moving for all three lines, the Δphil1 mutant exhibited significantly decreased trajectory lengths and mean and maximum velocities compared to the parental parasite line. These effects were either partially or fully restored upon complementation of the Δphil1 mutant. These results show that alterations in morphology may have a significant impact on T. gondii motility in an extracellular matrix-like environment, provide a possible explanation for the decreased fitness of Δphil1 parasites in vivo, and demonstrate the utility of the quantitative three-dimensional assay for studying parasite motility. PMID:24489670

  9. Expression profiling of colon cancer cell lines and colon biopsies: Towards a screening system for potential cancer-preventive compounds

    NARCIS (Netherlands)

    Erk, M.J. van; Krul, C.A.M.; Caldenhoven, E.; Stierum, R.H.; Peters, W.H.; Woutersen, R.A.; Ommen, B. van

    2005-01-01

    Interest in mechanisms of colon cancer prevention by food compounds is strong and research in this area is often performed with cultured colon cancer cells. In order to assess utility for screening of potential cancer-preventive (food) compounds, expression profiles of 14 human cell lines derived fr

  10. Expression profiling of colon cancer cell lines and colon biopsies: towards a screening system for potential cancer-preventive compounds.

    NARCIS (Netherlands)

    Erk, M.J. van; Krul, C.A.; Caldenhoven, E.; Stierum, R.H.; Peters, W.H.M.; Woutersen, R.A.; Ommen, B.

    2005-01-01

    Interest in mechanisms of colon cancer prevention by food compounds is strong and research in this area is often performed with cultured colon cancer cells. In order to assess utility for screening of potential cancer-preventive (food) compounds, expression profiles of 14 human cell lines derived fr

  11. Screening Metastasis-associated Genes from Anoikis Resistant A549 Lung Cancer Cells by Human Genome Array

    Directory of Open Access Journals (Sweden)

    Xiaoping WANG

    2010-01-01

    Full Text Available Background and objective As a barrier to metastases, cells normally undergo apoptosis after they lose contact with their extra cellular matrix (ECM. This process has been termed “anoikis”. Tumour cells that acquire malignant potential have developed mechanisms to resist anoikis and thereby survive after detachment from their primary site while traveling through the lymphatic and circulatory systems. This “anoikis resistance” is considered the first step to tumor metastases. The aim of this study was to screen metastasis-associated genes from anoikis resistant and adherent growth A549 lung cancer cell by Human Genome Array. Methods Establish anoikis resistant A549 lung cancer cell lines by using poly-hydroxyethyl methacrylate resin processed petri dishes, which causes cell free from adherent. The different expressed gene between anoikis resistant A549 cell and adherent growth A549 cell was tested using human V2.0 whole-genome oligonucleotide microarray, a product of Capitalbio Corporation, Beijing. Screen metastasis-associated genes. Results 745 different expressed genes were screened, including 63 highly metastasis-associated genes. Conclusion The successfully established anoikis resistant A549 cell lines and screened different expressed genes provide us basis for further research on metastasis of lung cancer.

  12. Vanished Twins and Misdiagnosed Sex: A Case Report with Implications in Prenatal Counseling Using Noninvasive Cell-Free DNA Screening.

    Science.gov (United States)

    Kelley, James F; Henning, George; Ambrose, Anthony; Adelman, Alan

    2016-01-01

    Cell-free DNA testing is a recently introduced method for screening pregnant women for fetal trisomy, which is associated with some common significant genetic diseases, as well as the sex of the fetus. The case described here demonstrates the connection between the ultrasound "vanishing twin" phenomenon and the misdiagnosis of prenatal sex using cell-free DNA testing. PMID:27170800

  13. Induced pluripotent stem cell-derived cardiomyocytes for cardiovascular disease modeling and drug screening.

    Science.gov (United States)

    Sharma, Arun; Wu, Joseph C; Wu, Sean M

    2013-12-24

    Human induced pluripotent stem cells (hiPSCs) have emerged as a novel tool for drug discovery and therapy in cardiovascular medicine. hiPSCs are functionally similar to human embryonic stem cells (hESCs) and can be derived autologously without the ethical challenges associated with hESCs. Given the limited regenerative capacity of the human heart following myocardial injury, cardiomyocytes derived from hiPSCs (hiPSC-CMs) have garnered significant attention from basic and translational scientists as a promising cell source for replacement therapy. However, ongoing issues such as cell immaturity, scale of production, inter-line variability, and cell purity will need to be resolved before human clinical trials can begin. Meanwhile, the use of hiPSCs to explore cellular mechanisms of cardiovascular diseases in vitro has proven to be extremely valuable. For example, hiPSC-CMs have been shown to recapitulate disease phenotypes from patients with monogenic cardiovascular disorders. Furthermore, patient-derived hiPSC-CMs are now providing new insights regarding drug efficacy and toxicity. This review will highlight recent advances in utilizing hiPSC-CMs for cardiac disease modeling in vitro and as a platform for drug validation. The advantages and disadvantages of using hiPSC-CMs for drug screening purposes will be explored as well.

  14. Tissue matrix arrays for high-throughput screening and systems analysis of cell function.

    Science.gov (United States)

    Beachley, Vince Z; Wolf, Matthew T; Sadtler, Kaitlyn; Manda, Srikanth S; Jacobs, Heather; Blatchley, Michael R; Bader, Joel S; Pandey, Akhilesh; Pardoll, Drew; Elisseeff, Jennifer H

    2015-12-01

    Cell and protein arrays have demonstrated remarkable utility in the high-throughput evaluation of biological responses; however, they lack the complexity of native tissue and organs. Here we spotted tissue extracellular matrix (ECM) particles as two-dimensional (2D) arrays or incorporated them with cells to generate three-dimensional (3D) cell-matrix microtissue arrays. We then investigated the responses of human stem, cancer and immune cells to tissue ECM arrays originating from 11 different tissues. We validated the 2D and 3D arrays as representative of the in vivo microenvironment by means of quantitative analysis of tissue-specific cellular responses, including matrix production, adhesion and proliferation, and morphological changes after culture. The biological outputs correlated with tissue proteomics, and network analysis identified several proteins linked to cell function. Our methodology enables broad screening of ECMs to connect tissue-specific composition with biological activity, providing a new resource for biomaterials research and further understanding of regeneration and disease mechanisms. PMID:26480475

  15. Hepatic differentiation of human pluripotent stem cells in miniaturized format suitable for high-throughput screen

    Directory of Open Access Journals (Sweden)

    Arnaud Carpentier

    2016-05-01

    Full Text Available The establishment of protocols to differentiate human pluripotent stem cells (hPSCs including embryonic (ESC and induced pluripotent (iPSC stem cells into functional hepatocyte-like cells (HLCs creates new opportunities to study liver metabolism, genetic diseases and infection of hepatotropic viruses (hepatitis B and C viruses in the context of specific genetic background. While supporting efficient differentiation to HLCs, the published protocols are limited in terms of differentiation into fully mature hepatocytes and in a smaller-well format. This limitation handicaps the application of these cells to high-throughput assays. Here we describe a protocol allowing efficient and consistent hepatic differentiation of hPSCs in 384-well plates into functional hepatocyte-like cells, which remain differentiated for more than 3 weeks. This protocol affords the unique opportunity to miniaturize the hPSC-based differentiation technology and facilitates screening for molecules in modulating liver differentiation, metabolism, genetic network, and response to infection or other external stimuli.

  16. Cytotoxicity screening of Melastoma malabathricum extracts on human breast cancer cell lines in vitro

    Institute of Scientific and Technical Information of China (English)

    Nurfariza; Ahmad; Roslen; Nur; Aizura; Mat; Alewi; Hadji; Ahamada; Mohammad; Syaiful; Bahari; Abdull; Rasad

    2014-01-01

    Objective:To screen the cytotoxic activity of Melasloma malabathricum(M,malubathricum)against human breast carreer cell line(MCF-7)in vitro.Methods:A three steps extraction protocol using n-hexane,chloroform and methanol as the solvents systems was carried out on leaves,stems and flowers of M.nalabathricum.Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations(100μg/mL,50μg/mL,25μg/mL,123μg/rnL and 6.25μg/mL).The evaluation of cell growth was determined using methylene blue assay.Results:Methanol extract from the leaves showed significant anticancer activity against MCF-7cell lines with the TC50value of 7.14μg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line,with the IC50value of 33.63μg/mL and 45.76μg/mL respectively after 72 h of treatment.Conclusions:The extracts from leaves and flowers of M.nulabatkricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC50at 7.14μg/mL while the extracts from stems showed less growth inhibition activity.

  17. Cytotoxicity screening of Melastoma malabathricum extracts on human breast cancer cell lines in vitro

    Institute of Scientific and Technical Information of China (English)

    Nurfariza Ahmad Roslen; Nur Aizura Mat Alewi; Hadji Ahamada

    2014-01-01

    Objective: To screen the cytotoxic activity of Melastoma malabathricum (M. malabathricum) against human breast cancer cell line (MCF-7) in vitro. Methods: A three steps extraction protocol using n-hexane, chloroform and methanol as the solvents systems was carried out on leaves, stems and flowers of M. malabathricum. Dimethyl sulfoxide was used in extracts dilution and serial dilutions were conducted to obtain five different extract concentrations (100 µg/mL, 50 µg/mL, 25 µg/mL, 12.5 µg/mL and 6.25 µg/mL). The evaluation of cell growth was determined using methylene blue assay.Results:Methanol extract from the leaves showed significant anticancer activity against MCF-7 cell lines with the IC50 value of 7.14 µg/ml while methanol and chloroform extract from the flowers exhibited a moderate activity towards MCF-7 cell line with the IC50 value of 33.63 µg/mL and 45.76 µg/mL respectively after 72 h of treatment.Conclusions:The extracts from leaves and flowers of M. malabathricum showed promising anticancer activity toward human breast cancer cell lines with the lowest IC50 at 7.14 µg/mL while the extracts from stems showed less growth inhibition activity.

  18. Screening of Highly Expressed CPEΔN Lung Cancer H1299 Cells

    Directory of Open Access Journals (Sweden)

    Jing SUN

    2015-06-01

    Full Text Available Background and objective The N-terminal truncated carboxypeptidase E (CPEΔN protein is a novel biomarker of tumor metastasis. This study screened the H1299 cell line with a highly expressed CPEΔN gene for in vivo imaging experiment. Methods Human CPEΔN gene was cloned into the luciferase lentiviral vector. H1299 cells transduced with CPEΔN or control lentiviral vectors were selected with 2 µg/mL puromycin. The expression of CPEΔN was identified through Western blot analysis, and luciferase activity was measured using luciferase reporters. Results The human CPEΔN lentiviral expression vector was successfully constructed. The transfection rate of H1299 cells by the lentivirus achieved 80%, with an infection multiplicity of 20. The H1299 cell line with high CPEΔN (H1299-CPEΔN expression was established, with an increase in CPEΔN expression by four times compared with the control lentivirus-transfected H1299 cell line (H1299-control. As H1299-CPEΔN and H1299-control can effectively decompose luciferase substrates, they can be applied in in vivo imaging. Conclusion H1299-CPEΔN and H1299-control can be used in in vivo imaging experiment for further research on molecular mechanisms and signal transduction to elucidate the role of CPEΔN in lung cancer metastasis.

  19. Actin-based motility of Listeria: Right-handed helical trajectories

    Science.gov (United States)

    Rangarajan, Murali

    2012-06-01

    Bacteria such as Listeria monocytogenes recruit cellular machinery to move in and between cells. Understanding the mechanism of motility, including force and torque generation and the resultant displacements, holds keys to numerous applications in medicine and biosensing. In this work, a simple back-of-the-envelope calculation is presented to illustrate that a biomechanical model of actin-based motility of a rigid surface through persistently attached filaments propelled by affinity-modulated molecular motors can produce a right-handed helical trajectory consistent with experimental observations. The implications of the mechanism to bacterial motility are discussed.

  20. Flagellar motility is necessary for Aeromonas hydrophila adhesion.

    Science.gov (United States)

    Qin, Yingxue; Lin, Guifang; Chen, Wenbo; Xu, Xiaojin; Yan, Qingpi

    2016-09-01

    Adhesion to host surface or cells is the initial step in bacterial pathogenesis, and the adhesion mechanisms of the fish pathogenic bacteria Aeromonas hydrophila were investigated in this study. First, a mutagenesis library of A. hydrophila that contained 332 random insertion mutants was constructed via mini-Tn10 Km mutagenesis. Four mutants displayed the most attenuated adhesion. Sequence analysis revealed that the mini-Tn10 insertion sites in the four mutant strains were flgC(GenBank accession numbers KX261880), cytb4(GenBank accession numbers JN133621), rbsR(GenBank accession numbers KX261881) and flgE(GenBank accession numbers JQ974982). To further study the roles of flgC and flgE in the adhesion of A. hydrophila, some biological characteristics of the wild-type strain B11, the mutants M121 and M240, and the complemented strains C121 and C240 were investigated. The results showed that the mutation in flgC or flgE led to the flagellar motility of A. hydrophila significant reduction or abolishment. flgC was not necessary for flagellar biosynthesis but was necessary for the full motility of A. hydrophila, flgE was involved in both flagellar biosynthesis and motility. The flagellar motility is necessary for A. hydrophila to adhere to the host mucus, which suggests flagellar motility plays crucial roles in the early infection process of this bacterium. PMID:27432325

  1. Development of droplets‐based microfluidic systems for single­‐cell high‐throughput screening

    DEFF Research Database (Denmark)

    Chen, Jun; Jensen, Thomas Glasdam; Godina, Alexei;

    2014-01-01

    investment, and a logarithmic increase to screen large combinatorial libraries over the decades also makes it gradually out of depth. Here, we are trying to develop a feasible high‐throughput system that uses microfluidics to compartmentalize a single cell for propagation and analysis in monodisperse...... picoliter aqueous droplets surround by an immiscible fluorinated oil phase. Our aim is to use this system to facilitate the screening process for both the biotechnology and food industry....

  2. 3D high-content screening for the identification of compounds that target cells in dormant tumor spheroid regions

    Energy Technology Data Exchange (ETDEWEB)

    Wenzel, Carsten; Riefke, Björn; Gründemann, Stephan; Krebs, Alice; Christian, Sven; Prinz, Florian; Osterland, Marc; Golfier, Sven; Räse, Sebastian [Bayer Pharma AG, Global Drug Discovery, Muellerstrasse 178, 13353 Berlin (Germany); Ansari, Nariman [Physical Biology Group, Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt (Germany); Esner, Milan; Bickle, Marc [Max Planck Institute of Molecular Cell Biology and Genetics, High-Throughput Technology Development Studio (TDS), Dresden (Germany); Pampaloni, Francesco; Mattheyer, Christian; Stelzer, Ernst H. [Physical Biology Group, Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt (Germany); Parczyk, Karsten; Prechtl, Stefan [Bayer Pharma AG, Global Drug Discovery, Muellerstrasse 178, 13353 Berlin (Germany); Steigemann, Patrick, E-mail: Patrick.Steigemann@bayer.com [Bayer Pharma AG, Global Drug Discovery, Muellerstrasse 178, 13353 Berlin (Germany)

    2014-04-15

    Cancer cells in poorly vascularized tumor regions need to adapt to an unfavorable metabolic microenvironment. As distance from supplying blood vessels increases, oxygen and nutrient concentrations decrease and cancer cells react by stopping cell cycle progression and becoming dormant. As cytostatic drugs mainly target proliferating cells, cancer cell dormancy is considered as a major resistance mechanism to this class of anti-cancer drugs. Therefore, substances that target cancer cells in poorly vascularized tumor regions have the potential to enhance cytostatic-based chemotherapy of solid tumors. With three-dimensional growth conditions, multicellular tumor spheroids (MCTS) reproduce several parameters of the tumor microenvironment, including oxygen and nutrient gradients as well as the development of dormant tumor regions. We here report the setup of a 3D cell culture compatible high-content screening system and the identification of nine substances from two commercially available drug libraries that specifically target cells in inner MCTS core regions, while cells in outer MCTS regions or in 2D cell culture remain unaffected. We elucidated the mode of action of the identified compounds as inhibitors of the respiratory chain and show that induction of cell death in inner MCTS core regions critically depends on extracellular glucose concentrations. Finally, combinational treatment with cytostatics showed increased induction of cell death in MCTS. The data presented here shows for the first time a high-content based screening setup on 3D tumor spheroids for the identification of substances that specifically induce cell death in inner tumor spheroid core regions. This validates the approach to use 3D cell culture screening systems to identify substances that would not be detectable by 2D based screening in otherwise similar culture conditions. - Highlights: • Establishment of a novel method for 3D cell culture based high-content screening. • First reported high

  3. 3D high-content screening for the identification of compounds that target cells in dormant tumor spheroid regions.

    Science.gov (United States)

    Wenzel, Carsten; Riefke, Björn; Gründemann, Stephan; Krebs, Alice; Christian, Sven; Prinz, Florian; Osterland, Marc; Golfier, Sven; Räse, Sebastian; Ansari, Nariman; Esner, Milan; Bickle, Marc; Pampaloni, Francesco; Mattheyer, Christian; Stelzer, Ernst H; Parczyk, Karsten; Prechtl, Stefan; Steigemann, Patrick

    2014-04-15

    Cancer cells in poorly vascularized tumor regions need to adapt to an unfavorable metabolic microenvironment. As distance from supplying blood vessels increases, oxygen and nutrient concentrations decrease and cancer cells react by stopping cell cycle progression and becoming dormant. As cytostatic drugs mainly target proliferating cells, cancer cell dormancy is considered as a major resistance mechanism to this class of anti-cancer drugs. Therefore, substances that target cancer cells in poorly vascularized tumor regions have the potential to enhance cytostatic-based chemotherapy of solid tumors. With three-dimensional growth conditions, multicellular tumor spheroids (MCTS) reproduce several parameters of the tumor microenvironment, including oxygen and nutrient gradients as well as the development of dormant tumor regions. We here report the setup of a 3D cell culture compatible high-content screening system and the identification of nine substances from two commercially available drug libraries that specifically target cells in inner MCTS core regions, while cells in outer MCTS regions or in 2D cell culture remain unaffected. We elucidated the mode of action of the identified compounds as inhibitors of the respiratory chain and show that induction of cell death in inner MCTS core regions critically depends on extracellular glucose concentrations. Finally, combinational treatment with cytostatics showed increased induction of cell death in MCTS. The data presented here shows for the first time a high-content based screening setup on 3D tumor spheroids for the identification of substances that specifically induce cell death in inner tumor spheroid core regions. This validates the approach to use 3D cell culture screening systems to identify substances that would not be detectable by 2D based screening in otherwise similar culture conditions.

  4. Epidermal growth factor upregulates motility of Mat-LyLu rat prostate cancer cells partially via voltage-gated Na+ channel activity

    Science.gov (United States)

    Ding, Yanning; Brackenbury, William J.; Onganer, Pinar U.; Montano, Ximena; Porter, Louise M.; Bates, Lucy F.; Djamgoz, Mustafa B. A.

    2014-01-01

    The main aim of this investigation was to determine whether a functional relationship existed between epidermal growth factor (EGF) and voltage-gated sodium channel (VGSC) upregulation, both associated with strongly metastatic prostate cancer cells. Incubation with EGF for 24 h more than doubled VGSC current density. Similar treatment with EGF significantly and dose-dependently enhanced the cells’ migration through Transwell filters. Both the patch clamp recordings and the migration assay suggested that endogenous EGF played a similar role. Importantly, co-application of EGF and tetrodotoxin, a highly selective VGSC blocker, abolished 65% of the potentiating effect of EGF. It is suggested that a significant portion of the EGF-induced enhancement of migration occurred via VGSC activity. PMID:17960590

  5. The role of bacterial motility in the survival and spread of Pseudomonas fluorescens in soil and in the attachment and colonisation of wheat roots.

    Science.gov (United States)

    Turnbull, G A.; Morgan, J A.W.; Whipps, J M.; Saunders, J R.

    2001-06-01

    Motile and non-motile strains of Pseudomonas fluorescens SBW25 were constructed using different combinations of the lacZY, xylE and aph marker genes which allowed their detection and differentiation in soil, root and seed samples. The survival of motile and non-motile strains was investigated in both non-competitive and competitive assays in water and non-sterile soil. Although there was no difference between strains in water, the motile strain survived in significantly greater numbers than the non-motile strain after 21 days in soil. There was no significant difference between competitive assays, where motile and non-motile cells were co-inoculated into soil, and non-competitive assays where strains were inoculated separately. Bacterial survival decreased as matric potential increased from -224 to -17 kPa but matric potential had no significant effect on motile compared to non-motile strains. Vertical spread of both motile and non-motile strains was detected 6.4 mm from the inoculum zone after 14 days in the absence of percolating water. There was no significant difference, for either strain, in distance moved from the inoculum zone after 14, 26 or 40 days. The motile strain had a significant advantage in attachment to sterile wheat roots in both non-competitive and competitive studies. When the spatial colonisation of wheat root systems was assessed in non-sterile soil, there was no significant difference between the motile and non-motile strain from either seed or soil inoculum. However, when the whole root system was assessed as one sample unit, differences could be detected. Bacterial motility could contribute to survival in soil and the initial phase of colonisation, where attachment and movement onto the root surface are important. PMID:11377770

  6. Gliding motility of Babesia bovis merozoites visualized by time-lapse video microscopy.

    Directory of Open Access Journals (Sweden)

    Masahito Asada

    Full Text Available BACKGROUND: Babesia bovis is an apicomplexan intraerythrocytic protozoan parasite that induces babesiosis in cattle after transmission by ticks. During specific stages of the apicomplexan parasite lifecycle, such as the sporozoites of Plasmodium falciparum and tachyzoites of Toxoplasma gondii, host cells are targeted for invasion using a unique, active process termed "gliding motility". However, it is not thoroughly understood how the merozoites of B. bovis target and invade host red blood cells (RBCs, and gliding motility has so far not been observed in the parasite. METHODOLOGY/PRINCIPAL FINDINGS: Gliding motility of B. bovis merozoites was revealed by time-lapse video microscopy. The recorded images revealed that the process included egress of the merozoites from the infected RBC, gliding motility, and subsequent invasion into new RBCs. The gliding motility of B. bovis merozoites was similar to the helical gliding of Toxoplasma tachyzoites. The trails left by the merozoites were detected by indirect immunofluorescence assay using antiserum against B. bovis merozoite surface antigen 1. Inhibition of gliding motility by actin filament polymerization or depolymerization indicated that the gliding motility was driven by actomyosin dependent process. In addition, we revealed the timing of breakdown of the parasitophorous vacuole. Time-lapse image analysis of membrane-stained bovine RBCs showed formation and breakdown of the parasitophorous vacuole within ten minutes of invasion. CONCLUSIONS/SIGNIFICANCE: This is the first report of the gliding motility of B. bovis. Since merozoites of Plasmodium parasites do not glide on a substrate, the gliding motility of B. bovis merozoites is a notable finding.

  7. The role of versican G3 domain in regulating breast cancer cell motility including effects on osteoblast cell growth and differentiation in vitro – evaluation towards understanding breast cancer cell bone metastasis

    Directory of Open Access Journals (Sweden)

    Du William

    2012-08-01

    Full Text Available Abstract Background Versican is detected in the interstitial tissues at the invasive margins of breast carcinoma, is predictive of relapse, and negatively impacts overall survival rates. The versican G3 domain is important in breast cancer cell growth, migration and bone metastasis. However, mechanistic studies evaluating versican G3 enhanced breast cancer bone metastasis are limited. Methods A versican G3 construct was exogenously expressed in the 66c14 and the MC3T3-E1 cell line. Cells were observed through light microscopy and viability analyzed by Coulter Counter or determined with colorimetric proliferation assays. The Annexin V-FITC apoptosis detection kit was used to detect apoptotic activity. Modified Chemotactic Boyden chamber migration invasion assays were applied to observe tumor migration and invasion to bone stromal cells and MC3T3-E1 cells. Alkaline phosphatase (ALP staining and ALP ELISA assays were performed to observe ALP activity in MC3T3-E1 cells. Results In the four mouse breast cancer cell lines 67NR, 66c14, 4T07, and 4T1, 4T1 cells expressed higher levels of versican, and showed higher migration and invasion ability to MC3T3-E1 cells and primary bone stromal cells. 4T1 conditioned medium (CM inhibited MC3T3-E1 cell growth, and even lead to apoptosis. Only 4T1 CM prevented MC3T3-E1 cell differentiation, noted by inhibition of alkaline phosphatase (ALP activity. We exogenously expressed a versican G3 construct in a cell line that expresses low versican levels (66c14, and observed that the G3-expressing 66c14 cells showed enhanced cell migration and invasion to bone stromal and MC3T3-E1 cells. This observation was prevented by selective EGFR inhibitor AG1478, selective MEK inhibitor PD 98059, and selective AKT inhibitor Triciribine, but not by selective JNK inhibitor SP 600125. Versican G3 enhanced breast cancer cell invasion to bone stromal cells or osteoblast cells appears to occur through enhancing EGFR/ERK or AKT signaling

  8. Structure and electrical properties of screen printed contacts on silicon solar cells

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2011-04-01

    Full Text Available Purpose: The aim of the paper was to apply a conventional method - “screen printing” using micrometric pastes to improve the quality of forming front side metallization of monocrystalline solar cells.Design/methodology/approach: The topography of co-fired in the infrared belt furnace front contacts were investigated using confocal laser scanning microscope and scanning electron microscope with an energy dispersive X-ray (EDS spectrometer for microchemical analysis. There were researched both surface topography and cross section of front contacts using SEM microscope. Phase composition analyses of chosen front contacts were done using the XRD method. Front contacts were formed on the surface with different morphology of the solar cells: textured with coated antireflection layer, textured without coated antireflection layer, non-textured with coated antireflection layer, non-textured without coated antireflection layer. The medium size of the pyramids was measured using the atomic force microscope (AFM. Resistance of front electrodes was investigated using Transmission Line Model (TLM.Findings: The high of deposited front metallization has an influence on value obtained from the contact resistance. This high of silver contact depends on: a paste composition, obtained structure after fired into a infrared belt furnace, the quantity and type of creating connections material molecules between themselves and with a silicon substrate.Research limitations/implications: The contact resistance of the screen-printed front metallization depends not only on the paste composition and firing conditions, but is also strongly influenced by the surface morphology of the silicon substrate.Originality/value: This paper investigates the front contact formation using silver pastes about different composition on silicon solar cells in order to decrease contact resistance and increase efficiency in this way

  9. Inhibitory effects of secondary metabolites from the red alga Delisea pulchra on swarming motility of Proteus mirabilis

    DEFF Research Database (Denmark)

    Gram, Lone; de Nys, R.; Maximilien, R.;

    1996-01-01

    Abnormal, uncoordinated swarming motility of the opportunistic human pathogen Proteus mirabilis was seen when a crude extract of the Australian red alga Delisea pulchra was added to the medium, This occurred at concentrations at which growth rate, swimming motility, cell elongation, polynucleatio...

  10. A Multi-Modality CMOS Sensor Array for Cell-Based Assay and Drug Screening.

    Science.gov (United States)

    Chi, Taiyun; Park, Jong Seok; Butts, Jessica C; Hookway, Tracy A; Su, Amy; Zhu, Chengjie; Styczynski, Mark P; McDevitt, Todd C; Wang, Hua

    2015-12-01

    In this paper, we present a fully integrated multi-modality CMOS cellular sensor array with four sensing modalities to characterize different cell physiological responses, including extracellular voltage recording, cellular impedance mapping, optical detection with shadow imaging and bioluminescence sensing, and thermal monitoring. The sensor array consists of nine parallel pixel groups and nine corresponding signal conditioning blocks. Each pixel group comprises one temperature sensor and 16 tri-modality sensor pixels, while each tri-modality sensor pixel can be independently configured for extracellular voltage recording, cellular impedance measurement (voltage excitation/current sensing), and optical detection. This sensor array supports multi-modality cellular sensing at the pixel level, which enables holistic cell characterization and joint-modality physiological monitoring on the same cellular sample with a pixel resolution of 80 μm × 100 μm. Comprehensive biological experiments with different living cell samples demonstrate the functionality and benefit of the proposed multi-modality sensing in cell-based assay and drug screening.

  11. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    Science.gov (United States)

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from