Science.gov

Sample records for actively migrating headcuts

  1. Ephemeral Gully Headcut Development and Migration in Stratified Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to examine the effect of vertical stratification in soil erodibility on the development and migration of steady-state headcut scour holes in upland concentrated flows typical of agricultural fields. Packed soil beds with a pre-formed step were subjected to identical simul...

  2. Effect of Soil Stratification on the Development and Migration of Headcuts in Upland Concentrated Flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to examine the effect of vertical stratification in soil erodibility on the development and migration of steady-state headcut scour holes in upland concentrated flows typical of agricultural fields. Packed soil beds with a pre-formed step were subjected to identical simul...

  3. Headcut Erosion in Wyoming's Sweetwater Subbasin

    NASA Astrophysics Data System (ADS)

    Cox, Samuel E.; Booth, D. Terrance; Likins, John C.

    2016-02-01

    Increasing human population and intensive land use combined with a warming climate and chronically diminished snowpacks are putting more strain on water resources in the western United States. Properly functioning riparian systems slow runoff and store water, thus regulating extreme flows; however, riparian areas across the west are in a degraded condition with a majority of riparian systems not in proper functioning condition, and with widespread catastrophic erosion of water-storing peat and organic soils. Headcuts are the leading edge of catastrophic channel erosion. We used aerial imagery (1.4-3.3-cm pixel) to locate 163 headcuts in riparian areas in the Sweetwater subbasin of central Wyoming. We found 1-m—the generally available standard resolution for land management—and 30-cm pixel imagery to be inadequate for headcut identification. We also used Structure-from-Motion models built from ground-acquired imagery to model 18 headcuts from which we measured soil loss of 425-720 m3. Normalized by channel length, this represents a loss of 1.1-1.8 m3 m-1 channel. Monitoring headcuts, either from ground or aerial imagery, provides an objective indicator of sustainable riparian land management and identifies priority disturbance-mitigation areas. Image-based headcut monitoring must use data on the order of 3.3 cm ground sample distance, or greater resolution, to effectively capture the information needed for accurate assessments of riparian conditions.

  4. Evaluation of a gully headcut retreat model using multitemporal aerial photographs and digital elevation models

    NASA Astrophysics Data System (ADS)

    Campo-Bescós, M. A.; Flores-Cervantes, J. H.; Bras, R. L.; Casalí, J.; Giráldez, J. V.

    2013-12-01

    large fraction of soil erosion in temperate climate systems proceeds from gully headcut growth processes. Nevertheless, headcut retreat is not well understood. Few erosion models include gully headcut growth processes, and none of the existing headcut retreat models have been tested against long-term retreat rate estimates. In this work the headcut retreat resulting from plunge pool erosion in the Channel Hillslope Integrated Landscape Development (CHILD) model is calibrated and compared to long-term evolution measurements of six gullies at the Bardenas Reales, northeast Spain. The headcut retreat module of CHILD was calibrated by adjusting the shape factor parameter to fit the observed retreat and volumetric soil loss of one gully during a 36 year period, using reported and collected field data to parameterize the rest of the model. To test the calibrated model, estimates by CHILD were compared to observations of headcut retreat from five other neighboring gullies. The differences in volumetric soil loss rates between the simulations and observations were less than 0.05 m3 yr-1, on average, with standard deviations smaller than 0.35 m3 yr-1. These results are the first evaluation of the headcut retreat module implemented in CHILD with a field data set. These results also show the usefulness of the model as a tool for simulating long-term volumetric gully evolution due to plunge pool erosion.

  5. Rill development, headcut migration, and sediment efflux from an evolving experimental landscape

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted using a soil-mantled flume subjected to simulated rain and downstream baselevel lowering to quantify the growth, development, and evolution of rills and rill networks. Digital elevation models constructed using photogrammetric techniques greatly facilitated data acquisiti...

  6. Bursts of activity in collective cell migration

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-04-01

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

  8. Active migration and passive transport of malaria parasites.

    PubMed

    Douglas, Ross G; Amino, Rogerio; Sinnis, Photini; Frischknecht, Freddy

    2015-08-01

    Malaria parasites undergo a complex life cycle between their hosts and vectors. During this cycle the parasites invade different types of cells, migrate across barriers, and transfer from one host to another. Recent literature hints at a misunderstanding of the difference between active, parasite-driven migration and passive, circulation-driven movement of the parasite or parasite-infected cells in the various bodily fluids of mosquito and mammalian hosts. Because both active migration and passive transport could be targeted in different ways to interfere with the parasite, a distinction between the two ways the parasite uses to get from one location to another is essential. We discuss the two types of motion needed for parasite dissemination and elaborate on how they could be targeted by future vaccines or drugs.

  9. Autumn Hawk Migration: Activities for a Schoolyard Hawk Watch.

    ERIC Educational Resources Information Center

    Highsmith, R. Tod

    1980-01-01

    Suggests activities for the study of hawk migration: development of identification skills using the accompanying flying hawk silhouettes, photographs, and drawings; binocular spotting games; selection and outfitting of a hawk watching station; follow-up map study; ecological and historical perspectives. (NEC)

  10. Yugoslavia. "Migration" -- programme activities targeting men.

    PubMed

    Dzeletovic, A; Matovic-miljanovic, S

    1999-01-01

    In Yugoslavia, companies send their workers to different parts of the world, including countries with a high incidence of AIDS. It has been noted that it is characteristic for migrants to accommodate themselves to foreign conditions, which subsequently lead to health problems, especially with regards to reproductive and sexual health. Often, in the case of partner separation, men may seek sexual relations with an unknown partner and/or neglect to use proper protection. According to research carried out in Yugoslavia, there are critical gaps in workers' knowledge on sexual and reproductive health. Based on research results, an educational program for migrants, designed to train and strengthen individuals¿ capabilities and modify their risky behavior, was created. Program activities include production of brochures targeting those people travelling to countries with a high incidence of HIV/AIDS. In addition, a process for creating more cooperation between the state and other organizations at regional and local levels was initiated.

  11. Without gaps - 3D photo-reconstruction of gully headcuts by combined utilisation of UAV and close-range photogrammetry

    NASA Astrophysics Data System (ADS)

    Stöcker, Claudia; Karrasch, Pierre; Eltner, Anette

    2015-04-01

    Gully erosion is a worldwide phenomenon causing permanent degradation of fertile land. Especially in the Mediterranean, gullies contribute to high soil loss rates which necessitate multi-temporal and high resolution monitoring. Gullies naturally exhibit complex surface morphologies and hence are difficult to measure. Images acquired airborne or terrestrial are possible data sources for digital gully modelling due to availing of photogrammetric methods to achieve 3D models. In this regard unmanned airborne vehicles (UAVs) allow for low cost, flexible and frequent areal gully monitoring, but exhibit limitations as a result of the birds-eye view - i.e. at steep sidewalls and overhanging areas. Terrestrial images offer advantages at local assessments and can be obtained spontaneously as needed. However, images acquired from ground are not able to ensure areal coverage. To integrate the advantages of both data sources and to overcome the above mentioned limitations, this study introduces a methodological approach of combined utilisation of nadir UAV data and oblique terrestrial images for 3D photo reconstruction. Two gully headcuts in Andalusia (Spain) are analysed to confirm the suitability of the synergetic data usage. The results show that the UAV model of the gully, generated from images from flying heights of 15 m, implies inconsistency of data at slope gradients of 50 to 60 °. To eliminate these gaps additional terrestrial images can be integrated, which are geo-referenced solely using information of the already calculated 3D model and orthophoto from the UAV images. Referencing errors of the terrestrial point clouds are fixed by applying fine registration. The final merged digital gully model reveals a resolution of 0.5 cm and an accuracy of 1 cm. Concluding, high density point clouds based on the fusion of UAV and terrestrial image data show a significant improvement of 3D photo-reconstruction of two gully headcuts compared to detached processing of single data

  12. The annealing helicase and branch migration activities of Drosophila HARP.

    PubMed

    Kassavetis, George A; Kadonaga, James T

    2014-01-01

    HARP (SMARCAL1, MARCAL1) is an annealing helicase that functions in the repair and restart of damaged DNA replication forks through its DNA branch migration and replication fork regression activities. HARP is conserved among metazoans. HARP from invertebrates differs by the absence of one of the two HARP-specific domain repeats found in vertebrates. The annealing helicase and branch migration activity of invertebrate HARP has not been documented. We found that HARP from Drosophila melanogaster retains the annealing helicase activity of human HARP, the ability to disrupt D-loops and to branch migrate Holliday junctions, but fails to regress model DNA replication fork structures. A comparison of human and Drosophila HARP on additional substrates revealed that both HARPs are competent in branch migrating a bidirectional replication bubble composed of either DNA:DNA or RNA:DNA hybrid. Human, but not Drosophila, HARP is also capable of regressing a replication fork structure containing a highly stable poly rG:dC hybrid. Persistent RNA:DNA hybrids in vivo can lead to replication fork arrest and genome instability. The ability of HARP to strand transfer hybrids may signify a hybrid removal function for this enzyme, in vivo.

  13. Agricultural activity shapes the communication and migration patterns in Senegal

    NASA Astrophysics Data System (ADS)

    Martin-Gutierrez, S.; Borondo, J.; Morales, A. J.; Losada, J. C.; Tarquis, A. M.; Benito, R. M.

    2016-06-01

    The communication and migration patterns of a country are shaped by its socioeconomic processes. The economy of Senegal is predominantly rural, as agriculture employs over 70% of the labor force. In this paper, we use mobile phone records to explore the impact of agricultural activity on the communication and mobility patterns of the inhabitants of Senegal. We find two peaks of phone calls activity emerging during the growing season. Moreover, during the harvest period, we detect an increase in the migration flows throughout the country. However, religious holidays also shape the mobility patterns of the Senegalese people. Hence, in the light of our results, agricultural activity and religious holidays are the primary drivers of mobility inside the country.

  14. Agricultural activity shapes the communication and migration patterns in Senegal.

    PubMed

    Martin-Gutierrez, S; Borondo, J; Morales, A J; Losada, J C; Tarquis, A M; Benito, R M

    2016-06-01

    The communication and migration patterns of a country are shaped by its socioeconomic processes. The economy of Senegal is predominantly rural, as agriculture employs over 70% of the labor force. In this paper, we use mobile phone records to explore the impact of agricultural activity on the communication and mobility patterns of the inhabitants of Senegal. We find two peaks of phone calls activity emerging during the growing season. Moreover, during the harvest period, we detect an increase in the migration flows throughout the country. However, religious holidays also shape the mobility patterns of the Senegalese people. Hence, in the light of our results, agricultural activity and religious holidays are the primary drivers of mobility inside the country.

  15. Macrophage migration inhibitory factor (MIF) enzymatic activity and lung cancer.

    PubMed

    Mawhinney, Leona; Armstrong, Michelle E; O' Reilly, Ciaran; Bucala, Richard; Leng, Lin; Fingerle-Rowson, Gunter; Fayne, Darren; Keane, Michael P; Tynan, Aisling; Maher, Lewena; Cooke, Gordon; Lloyd, David; Conroy, Helen; Donnelly, Seamas C

    2015-04-16

    The cytokine macrophage migration inhibitory factor (MIF) possesses unique tautomerase enzymatic activity, which contributes to the biological functional activity of MIF. In this study, we investigated the effects of blocking the hydrophobic active site of the tautomerase activity of MIF in the pathogenesis of lung cancer. To address this, we initially established a Lewis lung carcinoma (LLC) murine model in Mif-KO and wild-type (WT) mice and compared tumor growth in a knock-in mouse model expressing a mutant MIF lacking enzymatic activity (Mif (P1G)). Primary tumor growth was significantly attenuated in both Mif-KO and Mif (P1G) mice compared with WT mice. We subsequently undertook a structure-based, virtual screen to identify putative small molecular weight inhibitors specific for the tautomerase enzymatic active site of MIF. From primary and secondary screens, the inhibitor SCD-19 was identified, which significantly attenuated the tautomerase enzymatic activity of MIF in vitro and in biological functional screens. In the LLC murine model, SCD-19, given intraperitoneally at the time of tumor inoculation, was found to significantly reduce primary tumor volume by 90% (p < 0.001) compared with the control treatment. To better replicate the human disease scenario, SCD-19 was given when the tumor was palpable (at d 7 after tumor inoculation) and, again, treatment was found to significantly reduce tumor volume by 81% (p < 0.001) compared with the control treatment. In this report, we identify a novel inhibitor that blocks the hydrophobic pocket of MIF, which houses its specific tautomerase enzymatic activity, and demonstrate that targeting this unique active site significantly attenuates lung cancer growth in in vitro and in vivo systems.

  16. Polydatin induces bone marrow stromal cells migration by activation of ERK1/2.

    PubMed

    Chen, ZhenQiu; Wei, QiuShi; Hong, GuoJu; Chen, Da; Liang, Jiang; He, Wei; Chen, Mei Hui

    2016-08-01

    Bone marrow stromal cells (BMSCs) have proven to be useful for the treatment of numerous human diseases. However, the reparative ability of BMSCs is limited by their poor migration. Polydatin, widely used in traditional Chinese remedies, has proven to exert protective effects to BMSCs. However, little is known about its role in BMSCs migration. In this study, we studied the effects of polydatin on rat BMSCs migration using the scratch wound healing and transwell migration assays. Our results showed polydatin could promote BMSCs migration. Further experiments showed activation of ERK 1/2, but not JNK, was required for polydatin-induced BMSCs migration, suggesting that polydatin may promote BMSCs migration via the ERK 1/2 signaling pathways. Taken together, our results indicate that polydatin might be beneficial for stem cell replacement therapy by improving BMSCs migration.

  17. An essential role for platelet-activating factor in activating mast cell migration following ultraviolet irradiation

    PubMed Central

    Chacón-Salinas, Rommel; Chen, Limo; Chávez-Blanco, Alma D.; Limón-Flores, Alberto Y.; Ma, Ying; Ullrich, Stephen E.

    2014-01-01

    The UVB (290–320 nm) radiation in sunlight is responsible for inducing skin cancer. Exposure to UV radiation is also immunosuppressive, and the systemic immune suppression induced by UV is a well-recognized risk factor for cancer induction. As UVB radiation is absorbed within the upper layers of the skin, indirect mechanisms must play a role in activating systemic immune suppression. One prominent example is mast cell migration, which from the skin to the draining LN is an essential step in the cascade of events leading to immune suppression. What triggers mast cell migration is not entirely clear. Here, we tested the hypothesis that PAF, a lipid mediator of inflammation produced by the skin in response to UV exposure, is involved. Mast cell-deficient mice (KitW-sh/W-sh) are resistant to the suppressive effect of UV radiation, and reconstituting mast cell-deficient mice with normal bone marrow-derived mast cells restores susceptibility to immunosuppression. However, when mast cells from PAFR−/− mice were used, the reconstituted mice were not susceptible to the suppressive effects of UV. Furthermore, PAFR−/− mice showed impaired UV-induced mast cell migration when compared with WT mice. Finally, injecting PAF into WT mice mimicked the effect of UV irradiation and induced mast cell migration but not in PAFR−/− mice. Our findings indicate that PAFR binding induces mast cells to migrate from the skin to the LNs, where they mediate immune suppression. PMID:24009177

  18. Matrix metalloproteinase 13 mediates nitric oxide activation of endothelial cell migration

    PubMed Central

    López-Rivera, Esther; Lizarbe, Tania R.; Martínez-Moreno, Mónica; López-Novoa, José Miguel; Rodríguez-Barbero, Alicia; Rodrigo, José; Fernández, Ana Patricia; Álvarez-Barrientos, Alberto; Lamas, Santiago; Zaragoza, Carlos

    2005-01-01

    To explore the mechanisms by which NO elicits endothelial cell (EC) migration we used murine and bovine aortic ECs in an in vitro wound-healing model. We found that exogenous or endogenous NO stimulated EC migration. Moreover, migration was significantly delayed in ECs derived from endothelial NO synthase-deficient mice compared with WT murine aortic EC. To assess the contribution of matrix metalloproteinase (MMP)-13 to NO-mediated EC migration, we used RNA interference to silence MMP-13 expression in ECs. Migration was delayed in cells in which MMP-13 was silenced. In untreated cells MMP-13 was localized to caveolae, forming a complex with caveolin-1. Stimulation with NO disrupted this complex and significantly increased extracellular MMP-13 abundance, leading to collagen breakdown. Our findings show that MMP-13 is an important effector of NO-activated endothelial migration. PMID:15728377

  19. Endothelial activation drives lateral migration and diapedesis of leukocytes.

    PubMed

    Stock, Christian; Riethmuller, Christoph

    2011-01-01

    To invade a tissue, leukocytes have to overcome the endothelial barrier. Prior to trans-endothelial migration, leukocytes move laterally on the endothelial surface-searching for an emigration site. It is still unclear, how the actual diapedesis step is initiated and whether the endothelium has a decisive role. Here, video-microscopy was employed to investigate, whether lateral migration of leukocytes is correlated to their diapedesis rate. To address the contribution of each cell type, selective stimulation of either leukocytes or endothelial cells with TNFα was performed. Stimulation of endothelial cells alone was sufficient for maximal effects, thereby underlining their decisive role for leukocyte diapedesis. Concomitant to the TNFα-enhanced diapedesis rate, leukocyte adhesion was intensified and, unexpectedly, the lateral leukocyte migration was accelerated.

  20. Urokinase-type plasminogen activator is induced in migrating capillary endothelial cells

    PubMed Central

    1987-01-01

    Cellular migration is an essential component of invasive biological processes, many of which have been correlated with an increase in plasminogen activator production. Endothelial cell migration occurs in vivo during repair of vascular lesions and angiogenesis, and can be induced in vitro by wounding a confluent monolayer of cells. By combining the wounded monolayer model with a substrate overlay technique, we show that cells migrating from the edges of an experimental wound display an increase in urokinase-type plasminogen activator (uPA) activity, and that this activity reverts to background levels upon cessation of movement, when the wound has closed. Our results demonstrate a direct temporal relationship between endothelial cell migration and uPA activity, and suggest that induction of uPA activity is a component of the migratory process. PMID:3121633

  1. Activated Rac1 requires gp130 for Stat3 activation, cell proliferation and migration

    SciTech Connect

    Arulanandam, Rozanne; Geletu, Mulu; Feracci, Helene; Raptis, Leda

    2010-03-10

    Rac1 (Rac) is a member of the Rho family of small GTPases which controls cell migration by regulating the organization of actin filaments. Previous results suggested that mutationally activated forms of the Rho GTPases can activate the Signal Transducer and Activator of Transcription-3 (Stat3), but the exact mechanism is a matter of controversy. We recently demonstrated that Stat3 activity of cultured cells increases dramatically following E-cadherin engagement. To better understand this pathway, we now compared Stat3 activity levels in mouse HC11 cells before and after expression of the mutationally activated Rac1 (Rac{sup V12}), at different cell densities. The results revealed for the first time a dramatic increase in protein levels and activity of both the endogenous Rac and Rac{sup V12} with cell density, which was due to inhibition of proteasomal degradation. In addition, Rac{sup V12}-expressing cells had higher Stat3, tyrosine-705 phosphorylation and activity levels at all densities, indicating that Rac{sup V12} is able to activate Stat3. Further examination of the mechanism of Stat3 activation showed that Rac{sup V12} expression caused a surge in mRNA of Interleukin-6 (IL6) family cytokines, known potent Stat3 activators. Knockdown of gp130, the common subunit of this family reduced Stat3 activity, indicating that these cytokines may be responsible for the Stat3 activation by Rac{sup V12}. The upregulation of IL6 family cytokines was required for cell migration and proliferation induced by Rac{sup V12}, as shown by gp130 knockdown experiments, thus demonstrating that the gp130/Stat3 axis represents an essential effector of activated Rac for the regulation of key cellular functions.

  2. LXR activation inhibits chemokine-induced CD4-positive lymphocyte migration.

    PubMed

    Walcher, Daniel; Vasic, Dusica; Heinz, Philipp; Bach, Helga; Durst, Renate; Hausauer, Angelina; Hombach, Vinzenz; Marx, Nikolaus

    2010-07-01

    Migration of CD4-positive lymphocytes into the vessel wall is a critical step in atherogenesis. Recent data suggest that CD4-positive lymphocytes express the nuclear transcription factors Liver-X-Receptor (LXR) alpha and beta with an effect of LXR activators on TH1-cytokine release from these cells. However, the role of LXR in lymphocyte migration remains currently unexplored. Therefore, the present study investigated whether LXR activation might modulate chemokine-induced migration of these cells. Stimulation of CD4-positive lymphocytes with SDF-1 leads to a 2.5 +/- 0.8-fold increase in cell migration (P < 0.05; n = 12). Pretreatment of cells with the LXR activator T0901317 reduces this effect in a concentration-dependent manner to a maximal 0.9 +/- 0.4-fold induction at 1 micromol/L T0901317 (P < 0.05 compared to SDF-1-treated cells; n = 12). Similar results were obtained with the LXR activator GW3965. The effect of LXR activators on CD4-positive lymphocyte migration was mediated through an early inhibition of chemokine-induced PI-3 kinase activity as determined by PI-3 kinase activity assays. Downstream, T0901317 inhibited activation of the small GTPase Rac and phosphorylation of the myosin light chain (MLC). Moreover, LXR activator treatment reduced f-actin formation as well as ICAM3 translocation to the uropod of the cell, thus interfering with two important steps in T cell migration. Transfection of CD4-positive lymphocytes with LXRalpha/beta siRNA abolished T0901317 inhibitory effect on MLC phosphorylation and ICAM3 translocation. LXR activation by T0901317 or GW3965 inhibits chemokine-induced migration of CD4-positive lymphocytes. Given the crucial importance of chemokine-induced T cell migration in early atherogenesis, LXR activators may be promising tools to modulate this effect.

  3. Immature human dendritic cells enhance their migration through KCa3.1 channel activation.

    PubMed

    Crottès, David; Félix, Romain; Meley, Daniel; Chadet, Stéphanie; Herr, Florence; Audiger, Cindy; Soriani, Olivier; Vandier, Christophe; Roger, Sébastien; Angoulvant, Denis; Velge-Roussel, Florence

    2016-04-01

    Migration capacity is essential for dendritic cells (DCs) to present antigen to T cells for the induction of immune response. The DC migration is supposed to be a calcium-dependent process, while not fully understood. Here, we report a role of the KCa3.1/IK1/SK4 channels in the migration capacity of both immature (iDC) and mature (mDC) human CD14(+)-derived DCs. KCa3.1 channels were shown to control the membrane potential of human DC and the Ca(2+) entry, which is directly related to migration capacities. The expression of migration marker such as CCR5 and CCR7 was modified in both types of DCs by TRAM-34 (100nM). But, only the migration of iDC was decreased by use of both TRAM-34 and KCa3.1 siRNA. Confocal analyses showed a close localization of CCR5 with KCa3.1 in the steady state of iDC. Finally, the implication of KCa3.1 seems to be limited to the migration capacities as T cell activation of DCs appeared unchanged. Altogether, these results demonstrated that KCa3.1 channels have a pro-migratory effect on iDC migration. Our findings suggest that KCa3.1 in human iDC play a major role in their migration and constitute an attractive target for the cell therapy optimization.

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

    PubMed

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

    2014-08-01

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

  5. Hypoxia promotes Rab5 activation, leading to tumor cell migration, invasion and metastasis.

    PubMed

    Silva, Patricio; Mendoza, Pablo; Rivas, Solange; Díaz, Jorge; Moraga, Carolina; Quest, Andrew F G; Torres, Vicente A

    2016-05-17

    Hypoxia, a common condition of the tumor microenvironment, is associated with poor patient prognosis, tumor cell migration, invasion and metastasis. Recent evidence suggests that hypoxia alters endosome dynamics in tumor cells, leading to augmented cell proliferation and migration and this is particularly relevant, because endosomal components have been shown to be deregulated in cancer. The early endosome protein Rab5 is a small GTPase that promotes integrin trafficking, focal adhesion turnover, Rac1 activation, tumor cell migration and invasion. However, the role of Rab5 and downstream events in hypoxia remain unknown. Here, we identify Rab5 as a critical player in hypoxia-driven tumor cell migration, invasion and metastasis. Exposure of A549 human lung carcinoma, ZR-75, MDA-MB-231 and MCF-7 human breast cancer and B16-F10 mouse melanoma cells to hypoxia increased Rab5 activation, followed by its re-localization to the leading edge and association with focal adhesions. Importantly, Rab5 was required for hypoxia-driven cell migration, FAK phosphorylation and Rac1 activation, as shown by shRNA-targeting and transfection assays with Rab5 mutants. Intriguingly, the effect of hypoxia on both Rab5 activity and migration was substantially higher in metastatic B16-F10 cells than in poorly invasive B16-F0 cells. Furthermore, exogenous expression of Rab5 in B16-F0 cells predisposed to hypoxia-induced migration, whereas expression of the inactive mutant Rab5/S34N prevented the migration of B16-F10 cells induced by hypoxia. Finally, using an in vivo syngenic C57BL/6 mouse model, Rab5 expression was shown to be required for hypoxia-induced metastasis. In summary, these findings identify Rab5 as a key mediator of hypoxia-induced tumor cell migration, invasion and metastasis.

  6. Hypoxia promotes Rab5 activation, leading to tumor cell migration, invasion and metastasis

    PubMed Central

    Silva, Patricio; Mendoza, Pablo; Rivas, Solange; Díaz, Jorge; Moraga, Carolina; Quest, Andrew F.G.; Torres, Vicente A.

    2016-01-01

    Hypoxia, a common condition of the tumor microenvironment, is associated with poor patient prognosis, tumor cell migration, invasion and metastasis. Recent evidence suggests that hypoxia alters endosome dynamics in tumor cells, leading to augmented cell proliferation and migration and this is particularly relevant, because endosomal components have been shown to be deregulated in cancer. The early endosome protein Rab5 is a small GTPase that promotes integrin trafficking, focal adhesion turnover, Rac1 activation, tumor cell migration and invasion. However, the role of Rab5 and downstream events in hypoxia remain unknown. Here, we identify Rab5 as a critical player in hypoxia-driven tumor cell migration, invasion and metastasis. Exposure of A549 human lung carcinoma, ZR-75, MDA-MB-231 and MCF-7 human breast cancer and B16-F10 mouse melanoma cells to hypoxia increased Rab5 activation, followed by its re-localization to the leading edge and association with focal adhesions. Importantly, Rab5 was required for hypoxia-driven cell migration, FAK phosphorylation and Rac1 activation, as shown by shRNA-targeting and transfection assays with Rab5 mutants. Intriguingly, the effect of hypoxia on both Rab5 activity and migration was substantially higher in metastatic B16-F10 cells than in poorly invasive B16-F0 cells. Furthermore, exogenous expression of Rab5 in B16-F0 cells predisposed to hypoxia-induced migration, whereas expression of the inactive mutant Rab5/S34N prevented the migration of B16-F10 cells induced by hypoxia. Finally, using an in vivo syngenic C57BL/6 mouse model, Rab5 expression was shown to be required for hypoxia-induced metastasis. In summary, these findings identify Rab5 as a key mediator of hypoxia-induced tumor cell migration, invasion and metastasis. PMID:27121131

  7. Protein Kinase A Activity and Anchoring Are Required for Ovarian Cancer Cell Migration and Invasion

    PubMed Central

    McKenzie, Andrew J.; Campbell, Shirley L.; Howe, Alan K.

    2011-01-01

    Epithelial ovarian cancer (EOC) is the deadliest of the gynecological malignancies, due in part to its clinically occult metastasis. Therefore, understanding the mechanisms governing EOC dissemination and invasion may provide new targets for antimetastatic therapies or new methods for detection of metastatic disease. The cAMP-dependent protein kinase (PKA) is often dysregulated in EOC. Furthermore, PKA activity and subcellular localization by A-kinase anchoring proteins (AKAPs) are important regulators of cytoskeletal dynamics and cell migration. Thus, we sought to study the role of PKA and AKAP function in both EOC cell migration and invasion. Using the plasma membrane-directed PKA biosensor, pmAKAR3, and an improved migration/invasion assay, we show that PKA is activated at the leading edge of migrating SKOV-3 EOC cells, and that inhibition of PKA activity blocks SKOV-3 cell migration. Furthermore, we show that while the PKA activity within the leading edge of these cells is mediated by anchoring of type-II regulatory PKA subunits (RII), inhibition of anchoring of either RI or RII PKA subunits blocks cell migration. Importantly, we also show – for the first time – that PKA activity is up-regulated at the leading edge of SKOV-3 cells during invasion of a three-dimensional extracellular matrix and, as seen for migration, inhibition of either PKA activity or AKAP-mediated PKA anchoring blocks matrix invasion. These data are the first to demonstrate that the invasion of extracellular matrix by cancer cells elicits activation of PKA within the invasive leading edge and that both PKA activity and anchoring are required for matrix invasion. These observations suggest a role for PKA and AKAP activity in EOC metastasis. PMID:22028904

  8. Coordinated integrin activation by actin-dependent force during T-cell migration.

    PubMed

    Nordenfelt, Pontus; Elliott, Hunter L; Springer, Timothy A

    2016-10-10

    For a cell to move forward it must convert chemical energy into mechanical propulsion. Force produced by actin polymerization can generate traction across the plasma membrane by transmission through integrins to their ligands. However, the role this force plays in integrin activation is unknown. Here we show that integrin activity and cytoskeletal dynamics are reciprocally linked, where actin-dependent force itself appears to regulate integrin activity. We generated fluorescent tension-sensing constructs of integrin αLβ2 (LFA-1) to visualize intramolecular tension during cell migration. Using quantitative imaging of migrating T cells, we correlate tension in the αL or β2 subunit with cell and actin dynamics. We find that actin engagement produces tension within the β2 subunit to induce and stabilize an active integrin conformational state and that this requires intact talin and kindlin motifs. This supports a general mechanism where localized actin polymerization can coordinate activation of the complex machinery required for cell migration.

  9. Improvement of Human Keratinocyte Migration by a Redox Active Bioelectric Dressing

    PubMed Central

    Banerjee, Jaideep; Das Ghatak, Piya; Roy, Sashwati; Khanna, Savita; Sequin, Emily K.; Bellman, Karen; Dickinson, Bryan C.; Suri, Prerna; Subramaniam, Vish V.; Chang, Christopher J.; Sen, Chandan K.

    2014-01-01

    Exogenous application of an electric field can direct cell migration and improve wound healing; however clinical application of the therapy remains elusive due to lack of a suitable device and hence, limitations in understanding the molecular mechanisms. Here we report on a novel FDA approved redox-active Ag/Zn bioelectric dressing (BED) which generates electric fields. To develop a mechanistic understanding of how the BED may potentially influence wound re-epithelialization, we direct emphasis on understanding the influence of BED on human keratinocyte cell migration. Mapping of the electrical field generated by BED led to the observation that BED increases keratinocyte migration by three mechanisms: (i) generating hydrogen peroxide, known to be a potent driver of redox signaling, (ii) phosphorylation of redox-sensitive IGF1R directly implicated in cell migration, and (iii) reduction of protein thiols and increase in integrinαv expression, both of which are known to be drivers of cell migration. BED also increased keratinocyte mitochondrial membrane potential consistent with its ability to fuel an energy demanding migration process. Electric fields generated by a Ag/Zn BED can cross-talk with keratinocytes via redox-dependent processes improving keratinocyte migration, a critical event in wound re-epithelialization. PMID:24595050

  10. AMPK activity regulates trafficking of mitochondria to the leading edge during cell migration and matrix invasion

    PubMed Central

    Cunniff, Brian; McKenzie, Andrew J.; Heintz, Nicholas H.; Howe, Alan K.

    2016-01-01

    Cell migration is a complex behavior involving many energy-expensive biochemical events that iteratively alter cell shape and location. Mitochondria, the principal producers of cellular ATP, are dynamic organelles that fuse, divide, and relocate to respond to cellular metabolic demands. Using ovarian cancer cells as a model, we show that mitochondria actively infiltrate leading edge lamellipodia, thereby increasing local mitochondrial mass and relative ATP concentration and supporting a localized reversal of the Warburg shift toward aerobic glycolysis. This correlates with increased pseudopodial activity of the AMP-activated protein kinase (AMPK), a critically important cellular energy sensor and metabolic regulator. Furthermore, localized pharmacological activation of AMPK increases leading edge mitochondrial flux, ATP content, and cytoskeletal dynamics, whereas optogenetic inhibition of AMPK halts mitochondrial trafficking during both migration and the invasion of three-dimensional extracellular matrix. These observations indicate that AMPK couples local energy demands to subcellular targeting of mitochondria during cell migration and invasion. PMID:27385336

  11. Lumican Inhibits SNAIL-Induced Melanoma Cell Migration Specifically by Blocking MMP-14 Activity

    PubMed Central

    Stasiak, Marta; Boncela, Joanna; Perreau, Corinne; Karamanou, Konstantina; Chatron-Colliet, Aurore; Proult, Isabelle; Przygodzka, Patrycja; Chakravarti, Shukti; Maquart, François-Xavier; Kowalska, M. Anna; Wegrowski, Yanusz; Brézillon, Stéphane

    2016-01-01

    Lumican, a small leucine rich proteoglycan, inhibits MMP-14 activity and melanoma cell migration in vitro and in vivo. Snail triggers epithelial-mesenchymal transitions endowing epithelial cells with migratory and invasive properties during tumor progression. The aim of this work was to investigate lumican effects on MMP-14 activity and migration of Snail overexpressing B16F1 (Snail-B16F1) melanoma cells and HT-29 colon adenocarcinoma cells. Lumican inhibits the Snail induced MMP-14 activity in B16F1 but not in HT-29 cells. In Snail-B16F1 cells, lumican inhibits migration, growth, and melanoma primary tumor development. A lumican-based strategy targeting Snail-induced MMP-14 activity might be useful for melanoma treatment. PMID:26930497

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

    PubMed

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

    2017-03-01

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

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

    PubMed Central

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

    2017-01-01

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

  14. Activation of Dbl restores migration in polyamine-depleted intestinal epithelial cells via Rho-GTPases

    PubMed Central

    Bavaria, Mitulkumar N.; Bhattacharya, Sujoy; Johnson, Leonard R.

    2011-01-01

    Integrin binding to the extracellular matrix (ECM) activated Rho GTPases, Src, and focal adhesion kinase in intestinal epithelial cells (IEC)-6. Polyamine depletion inhibited activities of Rac1, RhoA, and Cdc42 and thereby migration. However, constitutively active (CA) Rac1 expression abolished the inhibitory effect of polyamine depletion, indicating that polyamines are involved in a process upstream of Rac1. In the present study, we examined the role of polyamines in the regulation of the guanine nucleotide exchange factor, diffuse B-cell lymphoma (Dbl), for Rho GTPases. Polyamine depletion decreased the level as well as the activation of Dbl protein. Dbl knockdown by siRNA altered cytoskeletal structure and decreased Rac1 activity and migration. Cells expressing CA-Dbl increased migration, Rac1 activity, and proliferation. CA-Dbl restored migration in polyamine-depleted cells by activating RhoA, Rac1, and Cdc42. CA-Dbl caused extensive reorganization of the F-actin cortex into stress fibers. Inhibition of Rac1 by NSC23766 significantly decreased migration of vector-transfected cells and CA-Dbl-transfected cells. However, the inhibition of migration was significantly higher in the vector-transfected cells compared with that seen in the CA-Dbl-transfected cells. Dbl localized in the perinuclear region in polyamine-depleted cells, whereas it localized with the stress fibers in control cells. CA-Dbl localized with stress fibers in both the control and polyamine-depleted cells. These results suggest that polyamines regulate the activation of Dbl, a membrane-proximal process upstream of Rac1. PMID:21372162

  15. Endotoxin activation of endothelium for polymorphonuclear leucocyte transendothelial migration and modulation by interferon-gamma.

    PubMed Central

    Issekutz, A C; Lopes, N

    1993-01-01

    Endotoxin [lipopolysaccharide (LPS)] is a potent inflammatory stimulus and can activate human umbilical vein endothelium (HUVE) for leucocyte adhesiveness and transendothelial migration. Here we investigated the role of HUVE-secreted cytokines in this process. When HUVE monolayers were grown on filters and preincubated for 3 hr with LPS, 51Cr-labelled polymorphonuclear leucocytes (PMNL) migrated across the HUVE in a dose- and time-dependent manner. Maximal PMNL transmigration with LPS (1 ng/ml) was 26 +/- 3% of added PMNL in 75 min. Neutralizing antibodies to interleukin-1 alpha (IL-1 alpha) and IL-1 beta, tumour necrosis factor-alpha (TNF-alpha), IL-8 or recombinant IL-1 receptor antagonist had no effect on the activation by LPS of the HUVE for supporting migration of PMNL. The HUVE 'activated state' declined with prolonged (22 hr) exposure to LPS, as reflected by a decrease in PMNL transendothelial migration to 5.5 +/- 1% and in the expression of the endothelial cell adhesion molecule, E-selectin, as compared to stimulation with LPS for 3 hr. However, simultaneous exposure to interferon-gamma (IFN-gamma) (200 IU/ml) and LPS maintained maximal PMNL transendothelial migration (28 +/- 4%) for at least 24 hr, prolonged E-selectin expression by HUVE and superinduced intracellular adhesion molecule-1 (ICAM-1) expression. The PMNL transendothelial migration was blocked by > 90% by monoclonal antibody (mAb) to CD18 with either 3 hr of LPS or 22 hr LPS + IFN-gamma stimulation. Migration was partially inhibited by mAb to E-selectin (30-40%) or to ICAM-1 (35-45%) and by a combination of both reagents (50-60%) under both stimulation conditions. Thus, LPS activation of HUVE for PMNL transendothelial migration: (a) does not require secretion of IL-1, TNF-alpha or IL-8 by the endothelium, (b) IFN-gamma enhances and prolongs endothelial activation by LPS and may increase leucocyte infiltration in LPS or bacterial inflammatory reactions, and (c) CD18-dependent mechanisms are

  16. P-Rex1 links mammalian target of rapamycin signaling to Rac activation and cell migration.

    PubMed

    Hernández-Negrete, Ivette; Carretero-Ortega, Jorge; Rosenfeldt, Hans; Hernández-García, Ricardo; Calderón-Salinas, J Victor; Reyes-Cruz, Guadalupe; Gutkind, J Silvio; Vázquez-Prado, José

    2007-08-10

    Polarized cell migration results from the transduction of extra-cellular cues promoting the activation of Rho GTPases with the intervention of multidomain proteins, including guanine exchange factors. P-Rex1 and P-Rex2 are Rac GEFs connecting Gbetagamma and phosphatidylinositol 3-kinase signaling to Rac activation. Their complex architecture suggests their regulation by protein-protein interactions. Novel mechanisms of activation of Rho GTPases are associated with mammalian target of rapamycin (mTOR), a serine/threonine kinase known as a central regulator of cell growth and proliferation. Recently, two independent multiprotein complexes containing mTOR have been described. mTORC1 links to the classical rapamycin-sensitive pathways relevant for protein synthesis; mTORC2 links to the activation of Rho GTPases and cytoskeletal events via undefined mechanisms. Here we demonstrate that P-Rex1 and P-Rex2 establish, through their tandem DEP domains, interactions with mTOR, suggesting their potential as effectors in the signaling of mTOR to Rac activation and cell migration. This possibility was consistent with the effect of dominant-negative constructs and short hairpin RNA-mediated knockdown of P-Rex1, which decreased mTOR-dependent leucine-induced activation of Rac and cell migration. Rapamycin, a widely used inhibitor of mTOR signaling, did not inhibit Rac activity and cell migration induced by leucine, indicating that P-Rex1, which we found associated to both mTOR complexes, is only active when in the mTORC2 complex. mTORC2 has been described as the catalytic complex that phosphorylates AKT/PKB at Ser-473 and elicits activation of Rho GTPases and cytoskeletal reorganization. Thus, P-Rex1 links mTOR signaling to Rac activation and cell migration.

  17. The biphasic nature of hypoxia-induced directional migration of activated human hepatic stellate cells.

    PubMed

    Novo, Erica; Povero, Davide; Busletta, Chiara; Paternostro, Claudia; di Bonzo, Lorenzo Valfrè; Cannito, Stefania; Compagnone, Alessandra; Bandino, Andrea; Marra, Fabio; Colombatto, Sebastiano; David, Ezio; Pinzani, Massimo; Parola, Maurizio

    2012-03-01

    Liver fibrogenesis is sustained by pro-fibrogenic myofibroblast-like cells (MFs), mainly originating from activated hepatic stellate cells (HSC/MFs) or portal (myo)fibroblasts, and is favoured by hypoxia-dependent angiogenesis. Human HSC/MFs were reported to express vascular-endothelial growth factor (VEGF) and VEGF-receptor type 2 and to migrate under hypoxic conditions. This study was designed to investigate early and delayed signalling mechanisms involved in hypoxia-induced migration of human HSC/MFs. Signal transduction pathways and intracellular generation of reactive oxygen species (ROS) were evaluated by integrating morphological, cell, and molecular biology techniques. Non-oriented and oriented migration were evaluated by using wound healing assay and the modified Boyden's chamber assay, respectively. The data indicate that hypoxia-induced migration of HSC/MFs is a biphasic process characterized by the following sequence of events: (a) an early (15 min) and mitochondria-related increased generation of intracellular ROS which (b) was sufficient to switch on activation of ERK1/2 and JNK1/2 that were responsible for the early phase of oriented migration; (c) a delayed and HIF-1α-dependent increase in VEGF expression (facilitated by ROS) and its progressive, time-dependent release in the extracellular medium that (d) was mainly responsible for sustained migration of HSC/MFs. Finally, immunohistochemistry performed on HCV-related fibrotic/cirrhotic livers revealed HIF-2α and haem-oxygenase-1 positivity in hepatocytes and α-SMA-positive MFs, indicating that MFs were likely to be exposed in vivo to both hypoxia and oxidative stress. In conclusion, hypoxia-induced migration of HSC/MFs involves an early, mitochondrial-dependent ROS-mediated activation of ERK and JNK, followed by a delayed- and HIF-1α-dependent up-regulation and release of VEGF.

  18. Activating the nuclear piston mechanism of 3D migration in tumor cells.

    PubMed

    Petrie, Ryan J; Harlin, Heather M; Korsak, Lulu I T; Yamada, Kenneth M

    2017-01-02

    Primary human fibroblasts have the remarkable ability to use their nucleus like a piston, switching from low- to high-pressure protrusions in response to the surrounding three-dimensional (3D) matrix. Although migrating tumor cells can also change how they migrate in response to the 3D matrix, it is not clear if they can switch between high- and low-pressure protrusions like primary fibroblasts. We report that unlike primary fibroblasts, the nuclear piston is not active in fibrosarcoma cells. Protease inhibition rescued the nuclear piston mechanism in polarized HT1080 and SW684 cells and generated compartmentalized pressure. Achieving compartmentalized pressure required the nucleoskeleton-cytoskeleton linker protein nesprin 3, actomyosin contractility, and integrin-mediated adhesion, consistent with lobopodia-based fibroblast migration. In addition, this activation of the nuclear piston mechanism slowed the 3D movement of HT1080 cells. Together, these data indicate that inhibiting protease activity during polarized tumor cell 3D migration is sufficient to restore the nuclear piston migration mechanism with compartmentalized pressure characteristic of nonmalignant cells.

  19. Participation of the urokinase-type plasminogen activator receptor (uPAR) in neutrophil transendothelial migration.

    PubMed

    Pliyev, Boris K; Antonova, Olga A; Menshikov, Mikhail

    2011-05-01

    The mechanisms underlying migration of neutrophils across endothelium are not completely understood. The urokinase-type plasminogen activator receptor (uPAR) plays a key role in neutrophil adhesion and migration. In the present study, we addressed whether uPAR regulates neutrophil transendothelial migration. We first showed that siRNA-mediated knockdown of uPAR in human umbilical vein endothelial cells (HUVECs) did not affect neutrophil migration across HUVEC monolayers indicating that endothelial uPAR does not regulate neutrophil transmigration. In contrast, the transmigration was significantly inhibited by Fab' fragment of anti-uPAR monoclonal antibody and proteolytically inactive urokinase (uPA), whereas inhibition of proteolytical activity of endogenous uPA (with amiloride or plasminogen activator inhibitor-1) did not affect the transmigration. Both the anti-uPAR Fab' fragment and proteolytically inactive uPA did not exert significant effects upon the transmigration conducted in the presence of F(ab')(2) fragment of blocking antibody to integrin Mac-1 indicating that uPAR regulates Mac-1-dependent transmigration. Mac-1-dependent, but not Mac-1-independent, transmigration was significantly reduced in the presence of N-acetyl-d-glucosamine and d-mannose, the saccharides that disrupt uPAR/Mac-1 association, but was unaffected in the presence of control saccharides (d-sorbitol and sucrose). We conclude that physical association of uPAR with Mac-1 mediates the regulatory effect of uPAR over the transmigration. Finally, we provide evidence that the functional cooperation between uPAR and Mac-1 is essential at both adhesion and diapedesis steps of neutrophil migration across endothelium. Thus, uPAR expressed on neutrophil plasma membrane regulates transendothelial migration independently of uPA proteolytical activity and acting as a cofactor for integrin Mac-1.

  20. Activated T lymphocytes migrate toward the cathode of DC electric fields in microfluidic devices.

    PubMed

    Li, Jing; Nandagopal, Saravanan; Wu, Dan; Romanuik, Sean F; Paul, Kausik; Thomson, Douglas J; Lin, Francis

    2011-04-07

    Immune cell migration is a fundamental process that enables immunosurveillance and immune responses. Understanding the mechanism of immune cell migration is not only of importance to the biology of cells, but also has high relevance to cell trafficking mediated physiological processes and diseases such as embryogenesis, wound healing, autoimmune diseases and cancers. In addition to the well-known chemical concentration gradient based guiding mechanism (i.e. chemotaxis), recent studies have shown that lymphocytes can respond to applied physiologically relevant direct current (DC) electric fields by migrating toward the cathode of the fields (i.e. electrotaxis) in both in vitro and in vivo settings. In the present study, we employed two microfluidic devices allowing controlled application of electric fields inside the microfluidic channel for quantitative studies of lymphocyte electrotaxis in vitro at the single cell level. The first device is fabricated by soft-lithography and the second device is made in glass with integrated on-chip electrodes. Using both devices, we for the first time showed that anti-CD3/CD28 antibodies activated human blood T cells migrate to the cathode of the applied DC electric field. This finding is consistent with previous electrotaxis studies on other lymphocyte subsets suggesting electrotaxis is a novel guiding mechanism for immune cell migration. Furthermore, the characteristics of electrotaxis and chemotaxis of activated T cells in PDMS microfluidic devices are compared.

  1. Nox4 and Duox1/2 Mediate Redox Activation of Mesenchymal Cell Migration by PDGF.

    PubMed

    Tyurin-Kuzmin, Pyotr A; Zhdanovskaya, Nadezhda D; Sukhova, Anna A; Sagaradze, George D; Albert, Eugene A; Ageeva, Ludmila V; Sharonov, George V; Vorotnikov, Alexander V; Tkachuk, Vsevolod A

    2016-01-01

    Platelet derived growth factor (PDGF) orchestrates wound healing and tissue regeneration by regulating recruitment of the precursor mesenchymal stromal cells (MSC) and fibroblasts. PDGF stimulates generation of hydrogen peroxide that is required for cell migration, but the sources and intracellular targets of H2O2 remain obscure. Here we demonstrate sustained live responses of H2O2 to PDGF and identify PKB/Akt, but not Erk1/2, as the target for redox regulation in cultured 3T3 fibroblasts and MSC. Apocynin, cell-permeable catalase and LY294002 inhibited PDGF-induced migration and mitotic activity of these cells indicating involvement of PI3-kinase pathway and H2O2. Real-time PCR revealed Nox4 and Duox1/2 as the potential sources of H2O2. Silencing of Duox1/2 in fibroblasts or Nox4 in MSC reduced PDGF-stimulated intracellular H2O2, PKB/Akt phosphorylation and migration, but had no such effect on Erk1/2. In contrast to PDGF, EGF failed to increase cytoplasmic H2O2, phosphorylation of PKB/Akt and migration of fibroblasts and MSC, confirming the critical impact of redox signaling. We conclude that PDGF-induced migration of mesenchymal cells requires Nox4 and Duox1/2 enzymes, which mediate redox-sensitive activation of PI3-kinase pathway and PKB/Akt.

  2. Nox4 and Duox1/2 Mediate Redox Activation of Mesenchymal Cell Migration by PDGF

    PubMed Central

    Sukhova, Anna A.; Sagaradze, George D.; Albert, Eugene A.; Ageeva, Ludmila V.; Sharonov, George V.; Tkachuk, Vsevolod A.

    2016-01-01

    Platelet derived growth factor (PDGF) orchestrates wound healing and tissue regeneration by regulating recruitment of the precursor mesenchymal stromal cells (MSC) and fibroblasts. PDGF stimulates generation of hydrogen peroxide that is required for cell migration, but the sources and intracellular targets of H2O2 remain obscure. Here we demonstrate sustained live responses of H2O2 to PDGF and identify PKB/Akt, but not Erk1/2, as the target for redox regulation in cultured 3T3 fibroblasts and MSC. Apocynin, cell-permeable catalase and LY294002 inhibited PDGF-induced migration and mitotic activity of these cells indicating involvement of PI3-kinase pathway and H2O2. Real-time PCR revealed Nox4 and Duox1/2 as the potential sources of H2O2. Silencing of Duox1/2 in fibroblasts or Nox4 in MSC reduced PDGF-stimulated intracellular H2O2, PKB/Akt phosphorylation and migration, but had no such effect on Erk1/2. In contrast to PDGF, EGF failed to increase cytoplasmic H2O2, phosphorylation of PKB/Akt and migration of fibroblasts and MSC, confirming the critical impact of redox signaling. We conclude that PDGF-induced migration of mesenchymal cells requires Nox4 and Duox1/2 enzymes, which mediate redox-sensitive activation of PI3-kinase pathway and PKB/Akt. PMID:27110716

  3. BRAF activates PAX3 to control muscle precursor cell migration during forelimb muscle development

    PubMed Central

    Shin, Jaeyoung; Watanabe, Shuichi; Hoelper, Soraya; Krüger, Marcus; Kostin, Sawa; Pöling, Jochen; Kubin, Thomas; Braun, Thomas

    2016-01-01

    Migration of skeletal muscle precursor cells is a key step during limb muscle development and depends on the activity of PAX3 and MET. Here, we demonstrate that BRAF serves a crucial function in formation of limb skeletal muscles during mouse embryogenesis downstream of MET and acts as a potent inducer of myoblast cell migration. We found that a fraction of BRAF accumulates in the nucleus after activation and endosomal transport to a perinuclear position. Mass spectrometry based screening for potential interaction partners revealed that BRAF interacts and phosphorylates PAX3. Mutation of BRAF dependent phosphorylation sites in PAX3 impaired the ability of PAX3 to promote migration of C2C12 myoblasts indicating that BRAF directly activates PAX3. Since PAX3 stimulates transcription of the Met gene we propose that MET signaling via BRAF fuels a positive feedback loop, which maintains high levels of PAX3 and MET activity required for limb muscle precursor cell migration. DOI: http://dx.doi.org/10.7554/eLife.18351.001 PMID:27906130

  4. Validating proposed migration equation and parameters' values as a tool to reproduce and predict (137)Cs vertical migration activity in Spanish soils.

    PubMed

    Olondo, C; Legarda, F; Herranz, M; Idoeta, R

    2017-01-05

    This paper shows the procedure performed to validate the migration equation and the migration parameters' values presented in a previous paper (Legarda et al., 2011) regarding the migration of (137)Cs in Spanish mainland soils. In this paper, this model validation has been carried out checking experimentally obtained activity concentration values against those predicted by the model. This experimental data come from the measured vertical activity profiles of 8 new sampling points which are located in northern Spain. Before testing predicted values of the model, the uncertainty of those values has been assessed with the appropriate uncertainty analysis. Once establishing the uncertainty of the model, both activity concentration values, experimental versus model predicted ones, have been compared. Model validation has been performed analyzing its accuracy, studying it as a whole and also at different depth intervals. As a result, this model has been validated as a tool to predict (137)Cs behaviour in a Mediterranean environment.

  5. Spatial control of active CDC-42 during collective migration of hypodermal cells in Caenorhabditis elegans.

    PubMed

    Ouellette, Marie-Hélène; Martin, Emmanuel; Lacoste-Caron, Germain; Hamiche, Karim; Jenna, Sarah

    2016-08-01

    Collective epithelial cell migration requires the maintenance of cell-cell junctions while enabling the generation of actin-rich protrusions at the leading edge of migrating cells. Ventral enclosure of Caenorhabditis elegans embryos depends on the collective migration of anterior-positioned leading hypodermal cells towards the ventral midline where they form new junctions with their contralateral neighbours. In this study, we characterized the zygotic function of RGA-7/SPV-1, a CDC-42/Cdc42 and RHO-1/RhoA-specific Rho GTPase-activating protein, which controls the formation of actin-rich protrusions at the leading edge of leading hypodermal cells and the formation of new junctions between contralateral cells. We show that RGA-7 controls these processes in an antagonistic manner with the CDC-42's effector WSP-1/N-WASP and the CDC-42-binding proteins TOCA-1/2/TOCA1. RGA-7 is recruited to spatially distinct locations at junctions between adjacent leading cells, where it promotes the accumulation of clusters of activated CDC-42. It also inhibits the spreading of these clusters towards the leading edge of the junctions and regulates their accumulation and distribution at new junctions formed between contralateral leading cells. Our study suggests that RGA-7 controls collective migration and junction formation between epithelial cells by spatially restricting active CDC-42 within cell-cell junctions.

  6. PKCδ regulates cortical radial migration by stabilizing the Cdk5 activator p35

    PubMed Central

    Zhao, Chun-tao; Li, Kun; Li, Jun-tao; Zheng, Wang; Liang, Xu-jun; Geng, An-qi; Li, Ning; Yuan, Xiao-bing

    2009-01-01

    Cyclin-dependent kinase 5 (Cdk5) and its activator p35 are critical for radial migration and lamination of cortical neurons. However, how this kinase is regulated by extracellular and intracellular signals during cortical morphogenesis remains unclear. Here, we show that PKCδ, a member of novel PKC expressing in cortical neurons, could stabilize p35 by direct phosphorylation. PKCδ attenuated the degradation of p35 but not its mutant derivative, which could not be phosphorylated by PKCδ. Down-regulation of PKCδ by in utero electroporation of specific small interference RNA (siRNA) severely impaired the radial migration of cortical neurons. This migration defect was similar to that caused by down-regulation of p35 and could be prevented by cotransfection with the wild-type but not the mutant p35. Furthermore, PKCδ could be activated by the promigratory factor brain-derived neurotrophic factor (BDNF) and was required for the activation of Cdk5 by BDNF. Both PKCδ and p35 were required for the promigratory effect of BDNF on cultured newborn neurons. Thus, PKCδ may promote cortical radial migration through maintaining the proper level of p35 in newborn neurons. PMID:19965374

  7. p53/PUMA expression in human pulmonary fibroblasts mediates cell activation and migration in silicosis

    PubMed Central

    Wang, Wei; Liu, Haijun; Dai, Xiaoniu; Fang, Shencun; Wang, Xingang; Zhang, Yingming; Yao, Honghong; Zhang, Xilong; Chao, Jie

    2015-01-01

    Phagocytosis of SiO2 into the lung causes an inflammatory cascade that results in fibroblast proliferation and migration, followed by fibrosis. Clinical evidence has indicated that the activation of alveolar macrophages by SiO2 produces rapid and sustained inflammation characterized by the generation of monocyte chemotactic protein 1, which, in turn, induces fibrosis. However, the details of events downstream of monocyte chemotactic protein 1 activity in pulmonary fibroblasts remain unclear. Here, to elucidate the role of p53 in fibrosis induced by silica, both the upstream molecular mechanisms and the functional effects on cell proliferation and migration were investigated. Experiments using primary cultured adult human pulmonary fibroblasts led to the following results: 1) SiO2 treatment resulted in a rapid and sustained increase in p53 and PUMA protein levels; 2) the MAPK and PI3K pathways were involved in the SiO2-induced alteration of p53 and PUMA expression; and 3) RNA interference targeting p53 and PUMA prevented the SiO2-induced increases in fibroblast activation and migration. Our study elucidated a link between SiO2-induced p53/PUMA expression in fibroblasts and cell migration, thereby providing novel insight into the potential use of p53/PUMA in the development of novel therapeutic strategies for silicosis treatment. PMID:26576741

  8. Effects of surface active agents on DNAPL migration and distribution in saturated porous media.

    PubMed

    Cheng, Zhou; Gao, Bin; Xu, Hongxia; Sun, Yuanyuan; Shi, Xiaoqing; Wu, Jichun

    2016-11-15

    Dissolved surface active agents such as surfactant and natural organic matter can affect the distribution and fate of dense nonaqueous liquids (DNAPLs) in soil and groundwater systems. This work investigated how two common groundwater surface active agents, humic acid (HA) and Tween 80, affected tetrachloroethylene (PCE) migration and source zone architecture in saturated porous media under environmentally relevant conditions. Batch experiments were first conducted to measure the contact angles and interfacial tensions (IFT) between PCE and quartz surface in water containing different amount of surface active agents. Results showed that the contact angle increased and IFT decreased with concentration of surface active agent increasing, and Tween 80 was much more effective than HA. Five 2-D flow cell experiments were then conducted. Correspondingly, Tween 80 showed strong effects on the migration and distribution of PCE in the porous media due to its ability to change the medium wettability from water-wet into intermediate/NAPL-wet. The downward migration velocities of the PCE in three Tween 80 cells were slower than those in the other two cells. In addition, the final saturation of the PCE in the cells containing surface active agents was higher than that in the water-only cell. Results from this work indicate that the presence of surface active agents in groundwater may strongly affect the fate and distribution of DNAPL through altering porous medium wettability.

  9. Dynamic myosin activation promotes collective morphology and migration by locally balancing oppositional forces from surrounding tissue.

    PubMed

    Aranjuez, George; Burtscher, Ashley; Sawant, Ketki; Majumder, Pralay; McDonald, Jocelyn A

    2016-06-15

    Migrating cells need to overcome physical constraints from the local microenvironment to navigate their way through tissues. Cells that move collectively have the additional challenge of negotiating complex environments in vivo while maintaining cohesion of the group as a whole. The mechanisms by which collectives maintain a migratory morphology while resisting physical constraints from the surrounding tissue are poorly understood. Drosophila border cells represent a genetic model of collective migration within a cell-dense tissue. Border cells move as a cohesive group of 6-10 cells, traversing a network of large germ line-derived nurse cells within the ovary. Here we show that the border cell cluster is compact and round throughout their entire migration, a shape that is maintained despite the mechanical pressure imposed by the surrounding nurse cells. Nonmuscle myosin II (Myo-II) activity at the cluster periphery becomes elevated in response to increased constriction by nurse cells. Furthermore, the distinctive border cell collective morphology requires highly dynamic and localized enrichment of Myo-II. Thus, activated Myo-II promotes cortical tension at the outer edge of the migrating border cell cluster to resist compressive forces from nurse cells. We propose that dynamic actomyosin tension at the periphery of collectives facilitates their movement through restrictive tissues.

  10. Coordinated integrin activation by actin-dependent force during T-cell migration

    PubMed Central

    Nordenfelt, Pontus; Elliott, Hunter L.; Springer, Timothy A.

    2016-01-01

    For a cell to move forward it must convert chemical energy into mechanical propulsion. Force produced by actin polymerization can generate traction across the plasma membrane by transmission through integrins to their ligands. However, the role this force plays in integrin activation is unknown. Here we show that integrin activity and cytoskeletal dynamics are reciprocally linked, where actin-dependent force itself appears to regulate integrin activity. We generated fluorescent tension-sensing constructs of integrin αLβ2 (LFA-1) to visualize intramolecular tension during cell migration. Using quantitative imaging of migrating T cells, we correlate tension in the αL or β2 subunit with cell and actin dynamics. We find that actin engagement produces tension within the β2 subunit to induce and stabilize an active integrin conformational state and that this requires intact talin and kindlin motifs. This supports a general mechanism where localized actin polymerization can coordinate activation of the complex machinery required for cell migration. PMID:27721490

  11. Slit3 inhibits activator protein 1-mediated migration of malignant melanoma cells.

    PubMed

    Denk, Alexandra E; Braig, Simone; Schubert, Thomas; Bosserhoff, Anja K

    2011-11-01

    The repellent factor family of Slit molecules has been described to have repulsive function in the developing nervous system on growing axons expressing the Robo receptors. Alterations of the Slit/Robo system have been observed in various pathological conditions and in cancer. However, until today no detailed studies on Slit function on melanoma migration are available. Therefore, we analysed the mRNA expression in melanoma cells and found induction of Robo3 expression compared to normal melanocytes. Functional assays performed with melanoma cells revealed that treatment with Slit3 led to strong inhibition of migration. Interestingly, we observed down-regulation of AP-1 activity and target gene expression after Slit3 treatment contributing to the negative regulation of migration. Taken together, our data showed that Slit3 reduces the migratory activity of melanoma cells, potentially by repulsion of the cells in analogy to the neuronal system. Further studies will be necessary to prove Slit activity in vivo, but due to its function, Slit3 activity may be helpful in the treatment of melanoma.

  12. Macrophages migrate in an activation-dependent manner to chemokines involved in neuroinflammation

    PubMed Central

    2014-01-01

    Background In neuroinflammatory diseases, macrophages can play a dual role in the process of tissue damage, depending on their activation status (M1 / M2). M1 macrophages are considered to exert damaging effects to neurons, whereas M2 macrophages are reported to aid regeneration and repair of neurons. Their migration within the central nervous system may be of critical importance in the final outcome of neurodegeneration in neuroinflammatory diseases e.g. multiple sclerosis (MS). To provide insight into this process, we examined the migratory capacity of human monocyte-derived M1 and M2 polarised macrophages towards chemoattractants, relevant for neuroinflammatory diseases like MS. Methods Primary cultures of human monocyte-derived macrophages were exposed to interferon gamma and lipopolysaccharide (LPS) to evoke proinflammatory (M1) activation or IL-4 to evoke anti-inflammatory (M2) activation. In a TAXIScan assay, migration of M0, M1 and M2 towards chemoattractants was measured and quantified. Furthermore the adhesion capacity and the expression levels of integrins as well as chemokine receptors of M0, M1 and M2 were assessed. Alterations in cell morphology were analysed using fluorescent labelling of the cytoskeleton. Results Significant differences were observed between M1 and M2 macrophages in the migration towards chemoattractants. We show that M2 macrophages migrated over longer distances towards CCL2, CCL5, CXCL10, CXCL12 and C1q compared to non-activated (M0) and M1 macrophages. No differences were observed in the adhesion of M0, M1 and M2 macrophages to multiple matrix components, nor in the expression of integrins and chemokine receptors. Significant changes were observed in the cytoskeleton organization upon stimulation with CCL2, M0, M1 and M2 macrophages adopt a spherical morphology and the cytoskeleton is rapidly rearranged. M0 and M2 macrophages are able to form filopodia, whereas M1 macrophages only adapt a spherical morphology. Conclusions

  13. MYC-nick promotes cell migration by inducing fascin expression and Cdc42 activation

    PubMed Central

    Anderson, Sarah; Poudel, Kumud Raj; Roh-Johnson, Minna; Brabletz, Thomas; Yu, Ming; Borenstein-Auerbach, Nofit; Grady, William N.; Bai, Jihong; Moens, Cecilia B.; Eisenman, Robert N.; Conacci-Sorrell, Maralice

    2016-01-01

    MYC-nick is a cytoplasmic, transcriptionally inactive member of the MYC oncoprotein family, generated by a proteolytic cleavage of full-length MYC. MYC-nick promotes migration and survival of cells in response to chemotherapeutic agents or withdrawal of glucose. Here we report that MYC-nick is abundant in colonic and intestinal tumors derived from mouse models with mutations in the Wnt, TGF-β, and PI3K pathways. Moreover, MYC-nick is elevated in colon cancer cells deleted for FBWX7, which encodes the major E3 ligase of full-length MYC frequently mutated in colorectal cancers. MYC-nick promotes the migration of colon cancer cells assayed in 3D cultures or grown as xenografts in a zebrafish metastasis model. MYC-nick accelerates migration by activating the Rho GTPase Cdc42 and inducing fascin expression. MYC-nick, fascin, and Cdc42 are frequently up-regulated in cells present at the invasive front of human colorectal tumors, suggesting a coordinated role for these proteins in tumor migration. PMID:27566402

  14. Increase of mesenchymal stem cell migration by cannabidiol via activation of p42/44 MAPK.

    PubMed

    Schmuhl, Ellen; Ramer, Robert; Salamon, Achim; Peters, Kirsten; Hinz, Burkhard

    2014-02-01

    Migration and differentiation of mesenchymal stem cells (MSCs) are known to be involved in various regenerative processes such as bone healing. However, little is known about the pharmacotherapeutical options aiming at the mobilization and differentiation of MSCs. The present study therefore focussed on cannabinoids which have been demonstrated to exhibit tissue healing properties. Using Boyden chamber assays, the non-psychoactive phytocannabinoid cannabidiol (CBD) was found to increase the migration of adipose-derived MSCs in a time- and concentration-dependent manner. CBD-induced migration was inhibited by AM-630 (CB₂ receptor antagonist) and O-1602 (G protein-coupled receptor 55 [GRP55] agonist). Moreover, the promigratory effect of CBD was antagonized by inhibition of the p42/44 mitogen-activated protein kinase (MAPK) pathway which became activated upon CBD treatment. In line with this data, AM-630 and O-1602 attenuated CBD-induced p42/44 MAPK phosphorylation. A p42/44 MAPK-dependent promigratory effect was likewise demonstrated for the GPR55 antagonist O-1918 and the selective CB₂ receptor agonist JWH-133. Additional evidence for a functional effect of CBD on MSCs was provided by experiments demonstrating long-term stimulation with CBD to induce differentiation of MSCs into the osteoblastic lineage as evidenced by increased mineralization assessed by cresolphthalein complexone assay and enhanced activity of alkaline phosphatase. Collectively, this study demonstrates CBD to promote the migration of MSCs via activation of the CB₂ receptor and inhibition of GPR55 and to induce osteoblastic differentiation. CBD may therefore recruit MSCs to sites of calcifying tissue regeneration and subsequently support bone regeneration via an osteoanabolic action on MSCs.

  15. Neural crest specification and migration independently require NSD3-related lysine methyltransferase activity

    PubMed Central

    Jacques-Fricke, Bridget T.; Gammill, Laura S.

    2014-01-01

    Neural crest precursors express genes that cause them to become migratory, multipotent cells, distinguishing them from adjacent stationary neural progenitors in the neurepithelium. Histone methylation spatiotemporally regulates neural crest gene expression; however, the protein methyltransferases active in neural crest precursors are unknown. Moreover, the regulation of methylation during the dynamic process of neural crest migration is unclear. Here we show that the lysine methyltransferase NSD3 is abundantly and specifically expressed in premigratory and migratory neural crest cells. NSD3 expression commences before up-regulation of neural crest genes, and NSD3 is necessary for expression of the neural plate border gene Msx1, as well as the key neural crest transcription factors Sox10, Snail2, Sox9, and FoxD3, but not gene expression generally. Nevertheless, only Sox10 histone H3 lysine 36 dimethylation requires NSD3, revealing unexpected complexity in NSD3-dependent neural crest gene regulation. In addition, by temporally limiting expression of a dominant negative to migratory stages, we identify a novel, direct requirement for NSD3-related methyltransferase activity in neural crest migration. These results identify NSD3 as the first protein methyltransferase essential for neural crest gene expression during specification and show that NSD3-related methyltransferase activity independently regulates migration. PMID:25318671

  16. Night-time neuronal activation of Cluster N in a day- and night-migrating songbird.

    PubMed

    Zapka, Manuela; Heyers, Dominik; Liedvogel, Miriam; Jarvis, Erich D; Mouritsen, Henrik

    2010-08-01

    Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds' eyes strongly reduces neuronal activation. These findings suggest that Cluster N processes light-dependent magnetic compass information in night-migrating songbirds. The aim of this study was to test if Cluster N is active during daytime migration. We used behavioural molecular mapping based on ZENK activation to investigate if Cluster N is active in the meadow pipit (Anthus pratensis), a day- and night-migratory species. We found that Cluster N of meadow pipits shows high neuronal activity under dim-light at night, but not under full room-light conditions during the day. These data suggest that, in day- and night-migratory meadow pipits, the light-dependent magnetic compass, which requires an active Cluster N, may only be used during night-time, whereas another magnetosensory mechanism and/or other reference system(s), like the sun or polarized light, may be used as primary orientation cues during the day.

  17. Night-time neuronal activation of Cluster N in a day- and night-migrating songbird

    PubMed Central

    Zapka, Manuela; Heyers, Dominik; Liedvogel, Miriam; Jarvis, Erich D; Mouritsen, Henrik

    2010-01-01

    Magnetic compass orientation in a night-migratory songbird requires that Cluster N, a cluster of forebrain regions, is functional. Cluster N, which receives input from the eyes via the thalamofugal pathway, shows high neuronal activity in night-migrants performing magnetic compass-guided behaviour at night, whereas no activation is observed during the day, and covering up the birds’ eyes strongly reduces neuronal activation. These findings suggest that Cluster N processes light-dependent magnetic compass information in night-migrating songbirds. The aim of this study was to test if Cluster N is active during daytime migration. We used behavioural molecular mapping based on ZENK activation to investigate if Cluster N is active in the meadow pipit (Anthus pratensis), a day- and night-migratory species. We found that Cluster N of meadow pipits shows high neuronal activity under dim-light at night, but not under full room-light conditions during the day. These data suggest that, in day- and night-migratory meadow pipits, the light-dependent magnetic compass, which requires an active Cluster N, may only be used during night-time, whereas another magnetosensory mechanism and/or other reference system(s), like the sun or polarized light, may be used as primary orientation cues during the day. PMID:20618826

  18. Mechano-growth factor induces migration of rat mesenchymal stem cells by altering its mechanical properties and activating ERK pathway

    SciTech Connect

    Wu, Jiamin; Wu, Kewen; Lin, Feng; Luo, Qing; Yang, Li; Shi, Yisong; Song, Guanbin; Sung, Kuo-Li Paul

    2013-11-08

    Highlights: •MGF induced the migration of rat MSC in a concentration-dependent manner. •MGF enhanced the mechanical properties of rMSC in inducing its migration. •MGF activated the ERK 1/2 signaling pathway of rMSC in inducing its migration. •rMSC mechanics may synergy with ERK 1/2 pathway in MGF-induced rMSC migration. -- Abstract: Mechano-growth factor (MGF) generated by cells in response to mechanical stimulation has been identified as a mechano effector molecule, playing a key role in regulating mesenchymal stem cell (MSC) function, including proliferation and migration. However, the mechanism(s) underlying how MGF-induced MSC migration occurs is still unclear. In the present study, MGF motivated migration of rat MSCs (rMSCs) in a concentration-dependent manner and optimal concentration of MGF at 50 ng/mL (defined as MGF treatment in this paper) was demonstrated. Notably, enhancement of mechanical properties that is pertinent to cell migration, such as cell traction force and cell stiffness were found to respond to MGF treatment. Furthermore, MGF increased phosphorylation of extracellular signal-regulated kinase (ERK), ERK inhibitor (i.e., PD98059) suppressed ERK phosphorylation, and abolished MGF-induced rMSC migration were found, demonstrating that ERK is involved molecule for MGF-induced rMSC migration. These in vitro evidences of MGF-induced rMSC migration and its direct link to altering rMSC mechanics and activating the ERK pathway, uncover the underlying biomechanical and biological mechanisms of MGF-induced rMSC migration, which may help find MGF-based application of MSC in clinical therapeutics.

  19. GABA-B receptor activation inhibits the in vitro migration of malignant hepatocytes.

    PubMed

    Lodewyks, Carly; Rodriguez, Jose; Yan, Jing; Lerner, Betty; Lipschitz, Jeremy; Nfon, Charles; Rempel, Julia Darlene; Uhanova, Julia; Minuk, Gerald Yosel

    2011-06-01

    There are conflicting data regarding whether activation of γ-aminobutyric acid-B (GABA-B) receptors results in inhibition of tumor growth and invasion. The objectives of this study were to document the effects of the GABA-B receptor agonist baclofen on malignant hepatocyte proliferation and migration. We also sought to determine whether any effects on cell migration were mediated by changes in cyclic adenosine monophosphate (cAMP) signaling or matrix metalloproteinase (MMP) expression. Finally, GABA-B(1) and -B(2) receptor expression was documented in 2 malignant hepatocyte cell lines (PLC/PRF/5 and Huh-7) and 12 sets of human hepatocellular carcinoma and adjacent nontumor tissues. Cell proliferative activity was documented by WST-1 absorbance, migration by wound healing assays, cAMP levels by enzyme-linked immunoassay (ELISA), MMP by immunohistochemistry and ELISA, and GABA-B receptor expression by flow cytometry and reverse transcriptase - polymerase chain reaction. Although baclofen had no effect on cell proliferation, wound healing was delayed, an effect that was reversed by the GABA-B receptor antagonist CGP. cAMP levels were decreased in Huh-7 but not PLC cells exposed to baclofen. MMP expression remained unaltered in both cell lines. Finally, GABA-B(1) receptor expression was present and consistently expressed, but GABA-B(2) expression was limited and varied with the number of cell passages and (or) duration of culture. In conclusion, activation of GABA-B receptors has no effect on malignant hepatocyte proliferation but does decrease cell migration. This inhibitory effect may involve cAMP signaling but not MMP expression. GABA-B(2) receptor expression is limited and variable, which may help to explain discrepancies with previously published results.

  20. A Low-Level Carbon Dioxide Laser Promotes Fibroblast Proliferation and Migration through Activation of Akt, ERK, and JNK

    PubMed Central

    Shingyochi, Yoshiaki; Kanazawa, Shigeyuki; Tajima, Satoshi; Tanaka, Rica; Mizuno, Hiroshi; Tobita, Morikuni

    2017-01-01

    Background Low-level laser therapy (LLLT) with various types of lasers promotes fibroblast proliferation and migration during the process of wound healing. Although LLLT with a carbon dioxide (CO2) laser was also reported to promote wound healing, the underlying mechanisms at the cellular level have not been previously described. Herein, we investigated the effect of LLLT with a CO2 laser on fibroblast proliferation and migration. Materials and Methods Cultured human dermal fibroblasts were prepared. MTS and cell migration assays were performed with fibroblasts after LLLT with a CO2 laser at various doses (0.1, 0.5, 1.0, 2.0, or 5.0 J/cm2) to observe the effects of LLLT with a CO2 laser on the proliferation and migration of fibroblasts. The non-irradiated group served as the control. Moreover, western blot analysis was performed using fibroblasts after LLLT with a CO2 laser to analyze changes in the activities of Akt, extracellular signal-regulated kinase (ERK), and Jun N-terminal kinase (JNK), which are signaling molecules associated with cell proliferation and migration. Finally, the MTS assay, a cell migration assay, and western blot analysis were performed using fibroblasts treated with inhibitors of Akt, ERK, or JNK before LLLT with a CO2 laser. Results In MTS and cell migration assays, fibroblast proliferation and migration were promoted after LLLT with a CO2 laser at 1.0 J/cm2. Western blot analysis revealed that Akt, ERK, and JNK activities were promoted in fibroblasts after LLLT with a CO2 laser at 1.0 J/cm2. Moreover, inhibition of Akt, ERK, or JNK significantly blocked fibroblast proliferation and migration. Conclusions These findings suggested that LLLT with a CO2 laser would accelerate wound healing by promoting the proliferation and migration of fibroblasts. Activation of Akt, ERK, and JNK was essential for CO2 laser-induced proliferation and migration of fibroblasts. PMID:28045948

  1. PLEKHG3 enhances polarized cell migration by activating actin filaments at the cell front

    PubMed Central

    Nguyen, Trang Thi Thu; Park, Wei Sun; Park, Byung Ouk; Kim, Cha Yeon; Oh, Yohan; Kim, Jin Man; Choi, Hana; Kyung, Taeyoon; Kim, Cheol-Hee; Lee, Gabsang; Hahn, Klaus M.; Meyer, Tobias; Heo, Won Do

    2016-01-01

    Cells migrate by directing Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 (Cdc42) activities and by polymerizing actin toward the leading edge of the cell. Previous studies have proposed that this polarization process requires a local positive feedback in the leading edge involving Rac small GTPase and actin polymerization with PI3K likely playing a coordinating role. Here, we show that the pleckstrin homology and RhoGEF domain containing G3 (PLEKHG3) is a PI3K-regulated Rho guanine nucleotide exchange factor (RhoGEF) for Rac1 and Cdc42 that selectively binds to newly polymerized actin at the leading edge of migrating fibroblasts. Optogenetic inactivation of PLEKHG3 showed that PLEKHG3 is indispensable both for inducing and for maintaining cell polarity. By selectively binding to newly polymerized actin, PLEKHG3 promotes local Rac1/Cdc42 activation to induce more local actin polymerization, which in turn promotes the recruitment of more PLEKHG3 to induce and maintain cell front. Thus, autocatalytic reinforcement of PLEKHG3 localization to the leading edge of the cell provides a molecular basis for the proposed positive feedback loop that is required for cell polarization and directed migration. PMID:27555588

  2. Migration and invasion of drug-resistant lung adenocarcinoma cells are dependent on mitochondrial activity

    PubMed Central

    Jeon, Ji Hoon; Kim, Dong Keon; Shin, Youngmi; Kim, Hee Yeon; Song, Bomin; Lee, Eun Young; Kim, Jong Kwang; You, Hye Jin; Cheong, Heesun; Shin, Dong Hoon; Kim, Seong-Tae; Cheong, Jae-Ho; Kim, Soo Youl; Jang, Hyonchol

    2016-01-01

    A small proportion of cancer cells have stem-cell-like properties, are resistant to standard therapy and are associated with a poor prognosis. The metabolism of such drug-resistant cells differs from that of nearby non-resistant cells. In this study, the metabolism of drug-resistant lung adenocarcinoma cells was investigated. The expression of genes associated with oxidative phosphorylation in the mitochondrial membrane was negatively correlated with the prognosis of lung adenocarcinoma. Because the mitochondrial membrane potential (MMP) reflects the functional status of mitochondria and metastasis is the principal cause of death due to cancer, the relationship between MMP and metastasis was evaluated. Cells with a higher MMP exhibited greater migration and invasion than those with a lower MMP. Cells that survived treatment with cisplatin, a standard chemotherapeutic drug for lung adenocarcinoma, exhibited increased MMP and enhanced migration and invasion compared with parental cells. Consistent with these findings, inhibition of mitochondrial activity significantly impeded the migration and invasion of cisplatin-resistant cells. RNA-sequencing analysis indicated that the expression of mitochondrial complex genes was upregulated in cisplatin-resistant cells. These results suggested that drug-resistant cells have a greater MMP and that inhibition of mitochondrial activity could be used to prevent metastasis of drug-resistant lung adenocarcinoma cells. PMID:27932791

  3. Reconciling the discrepancies on the involvement of large-conductance Ca(2+)-activated K channels in glioblastoma cell migration.

    PubMed

    Catacuzzeno, Luigi; Caramia, Martino; Sforna, Luigi; Belia, Silvia; Guglielmi, Luca; D'Adamo, Maria Cristina; Pessia, Mauro; Franciolini, Fabio

    2015-01-01

    Glioblastoma (GBM) is the most common and aggressive primary brain tumor, and is notable for spreading so effectively through the brain parenchyma to make complete surgical resection virtually impossible, and prospect of life dismal. Several ion channels have been involved in GBM migration and invasion, due to their critical role in supporting volume changes and Ca(2+) influx occuring during the process. The large-conductance, Ca(2+)-activated K (BK) channels, markedly overexpressed in biopsies of patients with GBMs and in GBM cell lines, have attracted much interest and have been suggested to play a central role in cell migration and invasion as candidate channels for providing the ion efflux and consequent water extrusion that allow cell shrinkage during migration. Available experimental data on the role of BK channel in migration and invasion are not consistent though. While BK channels block typically resulted in inhibition of cell migration or in no effect, their activation would either enhance or inhibit the process. This short review reexamines the relevant available data on the topic, and presents a unifying paradigm capable of reconciling present discrepancies. According to this paradigm, BK channels would not contribute to migration under conditions where the [Ca(2+)] i is too low for their activation. They will instead positively contribute to migration for intermediate [Ca(2+)] i , insufficient as such to activate BK channels, but capable of predisposing them to cyclic activation following oscillatory [Ca(2+)] i increases. Finally, steadily active BK channels because of prolonged high [Ca(2+)] i would inhibit migration as their steady activity would be unsuitable to match the cyclic cell volume changes needed for proper cell migration.

  4. NHE1 activity contributes to migration and is necessary for proliferation of human gastric myofibroblasts.

    PubMed

    Czepán, Mátyás; Rakonczay, Zoltán; Varró, Andrea; Steele, Islay; Dimaline, Rod; Lertkowit, Nantaporn; Lonovics, János; Schnúr, Andrea; Biczó, György; Geisz, Andrea; Lázár, György; Simonka, Zsolt; Venglovecz, Viktória; Wittmann, Tibor; Hegyi, Péter

    2012-03-01

    Myofibroblasts play central roles in wound healing, deposition of the extracellular matrix and epithelial function. Their functions depend on migration and proliferation within the subepithelial matrix, which results in accelerated cellular metabolism. Upregulated metabolic pathways generate protons which need to be excreted to maintain intracellular pH (pH(i)). We isolated human gastric myofibroblasts (HGMs) from surgical specimens of five patients. Then we characterized, for the first time, the expression and functional activities of the Na(+)/H(+) exchanger (NHE) isoforms 1, 2 and 3, and the functional activities of the Na(+)/HCO(3)(-) cotransporter (NBC) and the anion exchanger (AE) in cultured HGMs using microfluorimetry, immunocytochemistry, reverse transcription polymerase chain reaction and immunoblot analysis. We showed that NHE1-3, NBC and AE activities are present in HGMs and that NHE1 is the most active of the NHEs. In scratch wound assays we also demonstrated (using the selective NHE inhibitor HOE-642) that carbachol and insulin like growth factor II (IGF-II) partly stimulate migration of HGMs in a NHE1-dependent manner. EdU incorporation assays revealed that IGF-II induces proliferation of HGMs which is inhibited by HOE-642. The results indicate that NHE1 is necessary for IGF-II-induced proliferation response of HGMs. Overall, we have characterized the pH(i) regulatory mechanisms of HGMs. In addition, we demonstrated that NHE1 activity contributes to both IGF-II- and carbachol-stimulated migration and that it is obligatory for IGF-II-induced proliferation of HGMs.

  5. Induction of pancreatic cancer cell migration by an autocrine epidermal growth factor receptor activation.

    PubMed

    Stock, Anna-Maria; Hahn, Stephan A; Troost, Gabriele; Niggemann, Bernd; Zänker, Kurt S; Entschladen, Frank

    2014-08-15

    Pancreatic cancer is characterized by aggressive local invasion and early metastasis formation. Active migration of the pancreatic cancer cells is essential for these processes. We have shown previously that the pancreatic cancer cells lines CFPAC1 and IMIM-PC2 show high migratory activity, and we have investigated herein the reason for this observation. Cell migration was assessed using a three-dimensional, collagen-based assay and computer-assisted cell tracking. The expression of receptor tyrosine kinases was determined by flow-cytometry and cytokine release was measured by an enzyme-linked immunoassay. Receptor function was blocked by antibodies or pharmacological enzyme inhibitors. Both cells lines express the epidermal growth factor receptor (EGFR) as well as its family-member ErbB2 and the platelet-derived growth factor receptor (PDGFR)α, whereas only weak expression was detected for ErbB3 and no expression of PDGFRβ. Pharmacological inhibition of the EGFR or ErbB2 significantly reduced the migratory activity in both cell lines, as did an anti-EGFR antibody. Interestingly, combination of the latter with an anti-PDGFR antibody led to an even more pronounced reduction. Both cell lines release detectable amounts of EGF. Thus, the high migratory activity of the investigated pancreatic cancer cell lines is due to autocrine EGFR activation and possibly of other receptor tyrosine kinases.

  6. Active Forearc Response to CO-NZ-CA Triple Junction Migration, Southern Central America

    NASA Astrophysics Data System (ADS)

    Morell, K.; Fisher, D.; Gardner, T. W.

    2007-12-01

    Southeast migration of the CO-NZ-CA triple junction at a rate of ~55 mm/yr results in an abrupt increase in convergence rate, slab thickness and subduction direction within the upper plate of the Central American convergent margin. At the triple junction, an active transform fault (the dextral Panama Fracture Zone) subducts beneath the Caribbean plate at the Middle America Trench, and juxtaposes the thick, orthogonal and shallow subduction of the Cocos plate against the thin, oblique and steeper subduction of the Nazca plate. New bedrock geology, Quaternary mapping and Ar/Ar dates of fluvial and volcanic deposits inboard of the triple junction provide evidence that both the outer and inner forearc of this system is actively responding to the dynamic changes presented by triple junction migration. Our results confirm that the Fila Costeña, a thin-skinned inner forearc thrust belt, is active and likely propagating in concert with triple junction migration. Mapping within the area overriding the Panama Fracture Zone indicates that thrusting develops only in those areas experiencing Cocos subduction; the thrust belt dies out coincident with the on-shore projection of the Panama Fracture Zone, and balanced cross-sections indicate a lateral gradient in the amount of shortening near the termination of the thrust belt. Along-strike variations in drainage basin morphometry suggest that drainage divides of the Fila Costeña are propagating to the southeast with the triple junction, resulting in hook-shaped drainage patterns and asymmetric basin shapes. A survey of a flight of 3-4 fluvial terraces along the Río Chiriquí Viejo indicates recent thrusting along a prominent thrust fault of the Fila Costeña. These terraces are also inset into multiple lahar flows with an upper surface tentatively constrained at ~507 ka based on an Ar/Ar hornblende plateau age. Recent work indicates that this thrust fault displaces surficial lahar deposits, suggesting that it must have become

  7. Activated protein C upregulates ovarian cancer cell migration and promotes unclottability of the cancer cell microenvironment

    PubMed Central

    ALTHAWADI, HAMDA; ALFARSI, HALEMA; BESBES, SAMAHER; MIRSHAHI, SHAHSOLTAN; DUCROS, ELODIE; RAFII, ARASH; POCARD, MARC; THERWATH, AMU; SORIA, JEANNETTE; MIRSHAHI, MASSOUD

    2015-01-01

    The objective of this study was to evaluate the role of activated protein C (aPC), known to be a physiological anticoagulant, in ovarian cancer cell activation as well as in loss of clotting of cancer ascitic fluid. The effect of aPC on an ovarian cancer cell line (OVCAR-3) was tested in regards to i) cell migration and adhesion with the use of adhesion and wound healing assays as well as a droplet test; ii) protein phosphorylation, evaluated by cyto-ELISA; iii) cell cycle modification assessed by flow cytometric DNA quantification; and iv) anticoagulant activity evaluated by the prolongation of partial thromboplastin time (aPTT) of normal plasma in the presence or absence of aPC-treated ovarian cancer cells. In addition, the soluble endothelial protein C receptor (sEPCR) was quantified by ELISA in ascitic fluid of patients with ovarian cancer. Our results showed that in the OVCAR-3 aPC-induced cells i) an increase in cell migration was noted, which was inhibited when anti-endothelial protein C receptor (EPCR) was added to the culture medium and which may act via MEK-ERK and Rho-GTPase pathways; ii) an increase in threonine, and to a lesser extent tyrosine phosphorylation; iii) cell cycle activation (G1 to S/G2); and iv) a 2-3-fold prolongation of aPTT of normal plasma. In the peritoneal fluid, the sEPCR concentration was 71±23 ng/ml. In conclusion, free aPC binds to membrane EPCR in ovarian cancer cells and induces cell migration via MEK-ERK and Rho-GTPase pathways. This binding could also explain the loss of clotting of peritoneal fluids. PMID:26082331

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

    SciTech Connect

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

    2007-02-15

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

  9. Visualizing Chemokine-Dependent T Cell Activation and Migration in Response to Central Nervous System Infection

    PubMed Central

    Carson, Monica J.; Wilson, Emma H.

    2014-01-01

    In response to central nervous system (CNS) injury and infection, astrocytes, neurons, and CNS vasculature express several chemokines, including CCL21. Quantitative polymerase chain reaction (qPCR), western blot, and immunohistochemical methods can quantify mRNA and protein expression. However, these methods do not quantify chemokine bioavailability and bioactivity, variables modified by many environ mental factors including composition of extracellular matrix (ECM). Here we illustrate how two-photon microscopy and carboxyfluorescein succinimidyl ester (CFSE or CFDA SE) labeling of T cells coupled with flow cytometry can be used as tools to assess chemokine-mediated regulation of T cell proliferation, activation, and migration. PMID:23625499

  10. Infiltrative microgliosis: activation and long-distance migration of subependymal microglia following periventricular insults.

    PubMed

    Carbonell, W Shawn; Murase, Shin-Ichi; Horwitz, Alan F; Mandell, James W

    2005-01-28

    BACKGROUND: Subventricular microglia (SVMs) are positioned at the interface of the cerebrospinal fluid and brain parenchyma and may play a role in periventricular inflammatory reactions. However, SVMs have not been previously investigated in detail due to the lack of a specific methodology for their study exclusive of deeper parenchymal microglia. METHODS: We have developed and characterized a novel model for the investigation of subventricular microglial reactions in mice using intracerebroventricular (ICV) injection of high-dose rhodamine dyes. Dynamic studies using timelapse confocal microscopy in situ complemented the histopathological analysis. RESULTS: We demonstrate that high-dose ICV rhodamine dye injection resulted in selective uptake by the ependyma and ependymal death within hours. Phagocytosis of ependymal debris by activated SVMs was evident by 1d as demonstrated by the appearance of rhodamine-positive SVMs. In the absence of further manipulation, labelled SVMs remained in the subventricular space. However, these cells exhibited the ability to migrate several hundred microns into the parenchyma towards a deafferentation injury of the hippocampus. This "infiltrative microgliosis" was verified in situ using timelapse confocal microscopy. Finally, supporting the disease relevance of this event, the triad of ependymal cell death, SVM activation, and infiltrative microgliosis was recapitulated by a single ICV injection of HIV-1 tat protein. CONCLUSIONS: Subependymal microglia exhibit robust activation and migration in periventricular inflammatory responses. Further study of this population of microglia may provide insight into neurological diseases with tendencies to involve the ventricular system and periventricular tissues.

  11. Infiltrative microgliosis: activation and long-distance migration of subependymal microglia following periventricular insults

    PubMed Central

    Carbonell, W Shawn; Murase, Shin-Ichi; Horwitz, Alan F; Mandell, James W

    2005-01-01

    Background Subventricular microglia (SVMs) are positioned at the interface of the cerebrospinal fluid and brain parenchyma and may play a role in periventricular inflammatory reactions. However, SVMs have not been previously investigated in detail due to the lack of a specific methodology for their study exclusive of deeper parenchymal microglia. Methods We have developed and characterized a novel model for the investigation of subventricular microglial reactions in mice using intracerebroventricular (ICV) injection of high-dose rhodamine dyes. Dynamic studies using timelapse confocal microscopy in situ complemented the histopathological analysis. Results We demonstrate that high-dose ICV rhodamine dye injection resulted in selective uptake by the ependyma and ependymal death within hours. Phagocytosis of ependymal debris by activated SVMs was evident by 1d as demonstrated by the appearance of rhodamine-positive SVMs. In the absence of further manipulation, labelled SVMs remained in the subventricular space. However, these cells exhibited the ability to migrate several hundred microns into the parenchyma towards a deafferentation injury of the hippocampus. This "infiltrative microgliosis" was verified in situ using timelapse confocal microscopy. Finally, supporting the disease relevance of this event, the triad of ependymal cell death, SVM activation, and infiltrative microgliosis was recapitulated by a single ICV injection of HIV-1 tat protein. Conclusions Subependymal microglia exhibit robust activation and migration in periventricular inflammatory responses. Further study of this population of microglia may provide insight into neurological diseases with tendencies to involve the ventricular system and periventricular tissues. PMID:15679892

  12. Migration of antimony from PET bottles into beverages: determination of the activation energy of diffusion and migration modelling compared with literature data.

    PubMed

    Welle, F; Franz, R

    2011-01-01

    Plastics bottles made from polyethylene terephthalate (PET) are increasingly used for soft drinks, mineral water, juices and beer. In this study a literature review is presented concerning antimony levels found both in PET materials as well as in foods and food simulants. On the other hand, 67 PET samples from the European bottle market were investigated for their residual antimony concentrations. A mean value of 224 ± 32 mg kg(-1) was found, the median was 220 mg kg(-1). Diffusion coefficients for antimony in PET bottle materials were experimentally determined at different temperature between 105 and 150°C. From these data, the activation energy of diffusion for antimony species from the PET bottle wall into beverages and food simulants was calculated. The obtained value of 189 kJ mol(-1) was found to be in good agreement with published data on PET microwave trays (184 kJ mol(-1)). Based on these results, the migration of antimony into beverages was predicted by mathematical migration modelling for different surface/volume ratios and antimony bottle wall concentrations. The results were compared with literature data as well as international legal limits and guidelines values for drinking water and the migration limit set from food packaging legislation. It was concluded that antimony levels in beverages due to migration from PET bottles manufactured according to the state of the art can never reach or exceed the European-specific migration limit of 40 microg kg(-1). Maximum migration levels caused by room-temperature storage even after 3 years will never be essentially higher than 2.5 microg kg(-1) and in any case will be below the European limit of 5 microg kg(-1) for drinking water. The results of this study confirm that the exposure of the consumer by antimony migration from PET bottles into beverages and even into edible oils reaches approximately 1% of the current tolerable daily intake (TDI) established by World Health Organisation (WHO). Having

  13. Fibulin-5 binds urokinase-type plasminogen activator and mediates urokinase-stimulated β1-integrin-dependent cell migration.

    PubMed

    Kapustin, Alexander; Stepanova, Victoria; Aniol, Natalia; Cines, Douglas B; Poliakov, Alexei; Yarovoi, Serge; Lebedeva, Tatiana; Wait, Robin; Ryzhakov, Grigory; Parfyonova, Yelena; Gursky, Yaroslav; Yanagisawa, Hiromi; Minashkin, Mikhail; Beabealashvilli, Robert; Vorotnikov, Alexander; Bobik, Alex; Tkachuk, Vsevolod

    2012-04-15

    uPA (urokinase-type plasminogen activator) stimulates cell migration through multiple pathways, including formation of plasmin and extracellular metalloproteinases, and binding to the uPAR (uPA receptor; also known as CD87), integrins and LRP1 (low-density lipoprotein receptor-related protein 1) which activate intracellular signalling pathways. In the present paper we report that uPA-mediated cell migration requires an interaction with fibulin-5. uPA stimulates migration of wild-type MEFs (mouse embryonic fibroblasts) (Fbln5+/+ MEFs), but has no effect on fibulin-5-deficient (Fbln5-/-) MEFs. Migration of MEFs in response to uPA requires an interaction of fibulin-5 with integrins, as MEFs expressing a mutant fibulin-5 incapable of binding integrins (Fbln(RGE/RGE) MEFs) do not migrate in response to uPA. Moreover, a blocking anti-(human β1-integrin) antibody inhibited the migration of PASMCs (pulmonary arterial smooth muscle cells) in response to uPA. Binding of uPA to fibulin-5 generates plasmin, which excises the integrin-binding N-terminal cbEGF (Ca2+-binding epidermal growth factor)-like domain, leading to loss of β1-integrin binding. We suggest that uPA promotes cell migration by binding to fibulin-5, initiating its cleavage by plasmin, which leads to its dissociation from β1-integrin and thereby unblocks the capacity of integrin to facilitate cell motility.

  14. Fibulin-5 binds urokinase-type plasminogen activator and mediates urokinase-stimulated β1-integrin-dependent cell migration

    PubMed Central

    Kapustin, Alexander; Stepanova, Victoria; Aniol, Natalia; Cines, Douglas B.; Poliakov, Alexei; Yarovoi, Serge; Lebedeva, Tatiana; Wait, Robin; Ryzhakov, Grigory; Parfyonova, Yelena; Gursky, Yaroslav; Yanagisawa, Hiromi; Minashkin, Mikhail; Beabealashvilli, Robert; Vorotnikov, Alexander; Bobik, Alex; Tkachuk, Vsevolod

    2015-01-01

    uPA (urokinase-type plasminogen activator) stimulates cell migration through multiple pathways, including formation of plasmin and extracellular metalloproteinases, and binding to the uPAR (uPA receptor; also known as CD87), integrins and LRP1 (low-density lipoprotein receptor-related protein 1) which activate intracellular signalling pathways. In the present paper we report that uPA-mediated cell migration requires an interaction with fibulin-5. uPA stimulates migration of wild-type MEFs (mouse embryonic fibroblasts) (Fbln5+/+ MEFs), but has no effect on fibulin-5-deficient (Fbln5−/−) MEFs. Migration of MEFs in response to uPA requires an interaction of fibulin-5 with integrins, as MEFs expressing a mutant fibulin-5 incapable of binding integrins (FblnRGE/RGE MEFs) do not migrate in response to uPA. Moreover, a blocking anti-(human β1-integrin) antibody inhibited the migration of PASMCs (pulmonary arterial smooth muscle cells) in response to uPA. Binding of uPA to fibulin-5 generates plasmin, which excises the integrin-binding N-terminal cbEGF (Ca2+ -binding epidermal growth factor)-like domain, leading to loss of β1-integrin binding. We suggest that uPA promotes cell migration by binding to fibulin-5, initiating its cleavage by plasmin, which leads to its dissociation from β1-integrin and thereby unblocks the capacity of integrin to facilitate cell motility. PMID:22280367

  15. Spatial distribution of protein kinase A activity during cell migration is mediated by A-kinase anchoring protein AKAP Lbc.

    PubMed

    Paulucci-Holthauzen, Adriana A; Vergara, Leoncio A; Bellot, Larry J; Canton, David; Scott, John D; O'Connor, Kathleen L

    2009-02-27

    Protein kinase A (PKA) has been suggested to be spatially regulated in migrating cells due to its ability to control signaling events that are critical for polarized actin cytoskeletal dynamics. Here, using the fluorescence resonance energy transfer-based A-kinase activity reporter (AKAR1), we find that PKA activity gradients form with the strongest activity at the leading edge and are restricted to the basal surface in migrating cells. The existence of these gradients was confirmed using immunocytochemistry using phospho-PKA substrate antibodies. This observation holds true for carcinoma cells migrating randomly on laminin-1 or stimulated to migrate on collagen I with lysophosphatidic acid. Phosphodiesterase inhibition allows the formation of PKA activity gradients; however, these gradients are no longer polarized. PKA activity gradients are not detected when a non-phosphorylatable mutant of AKAR1 is used, if PKA activity is inhibited with H-89 or protein kinase inhibitor, or when PKA anchoring is perturbed. We further find that a specific A-kinase anchoring protein, AKAP-Lbc, is a major contributor to the formation of these gradients. In summary, our data show that PKA activity gradients are generated at the leading edge of migrating cells and provide additional insight into the mechanisms of PKA regulation of cell motility.

  16. Spatial Distribution of Protein Kinase A Activity during Cell Migration Is Mediated by A-kinase Anchoring Protein AKAP Lbc*

    PubMed Central

    Paulucci-Holthauzen, Adriana A.; Vergara, Leoncio A.; Bellot, Larry J.; Canton, David; Scott, John D.; O'Connor, Kathleen L.

    2009-01-01

    Protein kinase A (PKA) has been suggested to be spatially regulated in migrating cells due to its ability to control signaling events that are critical for polarized actin cytoskeletal dynamics. Here, using the fluorescence resonance energy transfer-based A-kinase activity reporter (AKAR1), we find that PKA activity gradients form with the strongest activity at the leading edge and are restricted to the basal surface in migrating cells. The existence of these gradients was confirmed using immunocytochemistry using phospho-PKA substrate antibodies. This observation holds true for carcinoma cells migrating randomly on laminin-1 or stimulated to migrate on collagen I with lysophosphatidic acid. Phosphodiesterase inhibition allows the formation of PKA activity gradients; however, these gradients are no longer polarized. PKA activity gradients are not detected when a non-phosphorylatable mutant of AKAR1 is used, if PKA activity is inhibited with H-89 or protein kinase inhibitor, or when PKA anchoring is perturbed. We further find that a specific A-kinase anchoring protein, AKAP-Lbc, is a major contributor to the formation of these gradients. In summary, our data show that PKA activity gradients are generated at the leading edge of migrating cells and provide additional insight into the mechanisms of PKA regulation of cell motility. PMID:19106088

  17. Antioxidant activity of Coriandrum sativum and protection against DNA damage and cancer cell migration

    PubMed Central

    2013-01-01

    Background Coriandrum sativum is a popular culinary and medicinal herb of the Apiaceae family. Health promoting properties of this herb have been reported in pharmacognostical, phytochemical and pharmacological studies. However, studies on C. sativum have always focused on the aerial parts of the herb and scientific investigation on the root is limited. The aim of this research was to investigate the antioxidant and anticancer activities of C. sativum root, leaf and stem, including its effect on cancer cell migration, and its protection against DNA damage, with special focus on the roots. Methods Powdered roots, leaves and stems of C. sativum were extracted through sequential extraction using hexane, dichloromethane, ethyl acetate, methanol and water. Total phenolic content, FRAP and DPPH radical scavenging activities were measured. Anti-proliferative activitiy on the breast cancer cell line, MCF-7, was assayed using the MTT assay. Activities of the antioxidant enzymes, catalase, superoxide dismutase, glutathione peroxidase, and of the caspases-3, -8 and -9 were assayed on treatment with the extract. Cell cycle progression was analysed using flow cytometry. The scratch motility assay was used to assess inhibition of MCF-7 cell migration. DNA damage in 3 T3-L1 fibroblasts was evaluated by the comet assay. The components in the extract were identified by HPLC and GC-MS. Results The ethyl acetate extract of C. sativum roots showed the highest antiproliferative activity on MCF-7 cells (IC50 = 200.0 ± 2.6 μg/mL) and had the highest phenolic content, FRAP and DPPH scavenging activities among the extracts. C. sativum root inhibited DNA damage and prevented MCF-7 cell migration induced by H2O2, suggesting its potential in cancer prevention and inhibition of metastasis. The extract exhibited anticancer activity in MCF-7 cells by affecting antioxidant enzymes possibly leading to H2O2 accumulation, cell cycle arrest at the G2/M phase and apoptotic cell death by

  18. Concerted action of neuroepithelial basal shrinkage and active epithelial migration ensures efficient optic cup morphogenesis

    PubMed Central

    Sidhaye, Jaydeep; Norden, Caren

    2017-01-01

    Organ formation is a multi-scale event that involves changes at the intracellular, cellular and tissue level. Organogenesis often starts with the formation of characteristically shaped organ precursors. However, the cellular mechanisms driving organ precursor formation are often not clear. Here, using zebrafish, we investigate the epithelial rearrangements responsible for the development of the hemispherical retinal neuroepithelium (RNE), a part of the optic cup. We show that in addition to basal shrinkage of RNE cells, active migration of connected epithelial cells into the RNE is a crucial player in its formation. This cellular movement is driven by progressive cell-matrix contacts and actively translocates prospective RNE cells to their correct location before they adopt neuroepithelial fate. Failure of this migration during neuroepithelium formation leads to ectopic determination of RNE cells and consequently impairs optic cup formation. Overall, this study illustrates how spatiotemporal coordination between morphogenic movements and fate determination critically influences organogenesis. DOI: http://dx.doi.org/10.7554/eLife.22689.001 PMID:28372636

  19. Active and passive migration in boring isopods Limnoria spp. (Crustacea, Peracarida) from kelp holdfasts

    NASA Astrophysics Data System (ADS)

    Miranda, Leonardo; Thiel, Martin

    2008-10-01

    Many boring isopods inhabit positively buoyant substrata (wood and algae), which float after detachment, permitting passive migration of inhabitants. Based on observations from previous studies, it was hypothesized that juvenile, subadult and male isopods migrate actively, and will rapidly abandon substrata after detachment. In contrast, reproductive females and small offspring were predicted to remain in floating substrata and thus have a high probability to disperse passively via rafting. In order to test this hypothesis, a colonization and an emigration experiment were conducted with giant kelp ( Macrocystis integrifolia), the holdfasts of which are inhabited by boring isopods from the genus Limnoria. A survey of benthic substrata in the kelp forest confirmed that limnoriids inhabited the holdfasts and did not occur in holdfast-free samples. Results of the colonization experiment showed that all life history stages of the boring isopods immigrated into young, largely uncolonized holdfasts, and after 16 weeks all holdfasts were densely colonized. In the emigration experiment, all life history stages of the isopods rapidly abandoned the detached holdfasts — already 5 min after detachment only few individuals remained in the floating holdfasts. After this initial rapid emigration of isopods, little changes in isopod abundance occurred during the following 24 h, and at the end of the experiment some individuals of all life history stages still remained in the holdfasts. These results indicate that all life history stages of Limnoria participate in both active migration and passive dispersal. It is discussed that storm-related dynamics within kelp forests may contribute to intense mixing of local populations of these burrow-dwelling isopods, and that most immigrants to young holdfasts probably are individuals emigrating from old holdfasts detached during storm events. The fact that some individuals of all life history stages and both sexes remain in floating

  20. Smoothened Regulates Migration of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via Activation of Rho GTPase Signaling.

    PubMed

    Peng, Wei-Xiang; Zhu, Shang-Ling; Zhang, Bai-Yu; Shi, Yi-Ming; Feng, Xiao-Xue; Liu, Fang; Huang, Jian-Lin; Zheng, Song Guo

    2017-01-01

    Fibroblast-like synoviocytes (FLSs) acquire aggressive phenotypes characterized with enhanced migration abilities and inherent invasive qualities in rheumatoid arthritis (RA). Smoothened (Smo) is a key component of sonic hedgehog (Shh) signaling and contributes to tumor cell invasion and metastasis. The objective of this study is to investigate the role of Smo in the modulation of cell migration and explore the underlying molecular mechanism(s). FLSs were isolated from RA synovium. Shh levels were regulated by a Smo agonist (purmorphamine), Smo antagonist (KAAD-cyclopamine), or small interfering RNA targeting the Smo gene (Smo-siRNA) in RA-FLSs. Expression of Smo was detected by real-time PCR and western blot analysis. Cell migration was examined by Transwell assay and activation of Rho GTPases was measured by pull-down assays. Incubation with purmorphamine resulted in a significant increase of cell migration and activation of Rho GTPase signaling compared to controls (P < 0.05). However, treatment with KAAD-cyclopamine or transfection with Smo-siRNA suppressed migration of RA-FLSs and showed an inhibitory effect of Rho GTPase signaling. Together, these results suggest that Smo plays an important role in RA-FLSs migration through activation of Rho GTPase signaling and may contribute to progression of RA, thus, targeting Shh signal may have a therapeutic potential in patients with RA.

  1. Smoothened Regulates Migration of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via Activation of Rho GTPase Signaling

    PubMed Central

    Peng, Wei-xiang; Zhu, Shang-ling; Zhang, Bai-yu; Shi, Yi-ming; Feng, Xiao-xue; Liu, Fang; Huang, Jian-lin; Zheng, Song Guo

    2017-01-01

    Fibroblast-like synoviocytes (FLSs) acquire aggressive phenotypes characterized with enhanced migration abilities and inherent invasive qualities in rheumatoid arthritis (RA). Smoothened (Smo) is a key component of sonic hedgehog (Shh) signaling and contributes to tumor cell invasion and metastasis. The objective of this study is to investigate the role of Smo in the modulation of cell migration and explore the underlying molecular mechanism(s). FLSs were isolated from RA synovium. Shh levels were regulated by a Smo agonist (purmorphamine), Smo antagonist (KAAD-cyclopamine), or small interfering RNA targeting the Smo gene (Smo-siRNA) in RA-FLSs. Expression of Smo was detected by real-time PCR and western blot analysis. Cell migration was examined by Transwell assay and activation of Rho GTPases was measured by pull-down assays. Incubation with purmorphamine resulted in a significant increase of cell migration and activation of Rho GTPase signaling compared to controls (P < 0.05). However, treatment with KAAD-cyclopamine or transfection with Smo-siRNA suppressed migration of RA-FLSs and showed an inhibitory effect of Rho GTPase signaling. Together, these results suggest that Smo plays an important role in RA-FLSs migration through activation of Rho GTPase signaling and may contribute to progression of RA, thus, targeting Shh signal may have a therapeutic potential in patients with RA. PMID:28261216

  2. Distinct roles of AKT isoforms in regulating β1-integrin activity, migration, and invasion in prostate cancer

    PubMed Central

    Virtakoivu, Reetta; Pellinen, Teijo; Rantala, Juha K.; Perälä, Merja; Ivaska, Johanna

    2012-01-01

    AKT1 and AKT2 kinases have been shown to play opposite roles in breast cancer migration and invasion. In this study, an RNA interference screen for integrin activity inhibitors identified AKT1 as an inhibitor of β1-integrin activity in prostate cancer. Validation experiments investigating all three AKT isoforms demonstrated that, unlike in breast cancer, both AKT1 and AKT2 function as negative regulators of cell migration and invasion in PC3 prostate cancer cells. Down-regulation of AKT1 and AKT2, but not AKT3, induced activation of cell surface β1-integrins and enhanced adhesion, migration, and invasion. Silencing of AKT1 and AKT2 also resulted in increased focal adhesion size. Importantly, the mechanisms involved in integrin activity regulation were distinct for the two AKT isoforms. Silencing of AKT1 relieved feedback suppression of the expression and activity of several receptor tyrosine kinases, including EGFR and MET, with established cross-talk with β1-integrins. Silencing of AKT2, on the other hand, induced up-regulation of the microRNA-200 (miR-200) family, and overexpression of miR-200 was sufficient to induce integrin activity and cell migration in PC3 cells. Taken together, these data define an inhibitory role for both AKT1 and AKT2 in prostate cancer migration and invasion and highlight the cell type–specific actions of AKT kinases in the regulation of cell motility. PMID:22809628

  3. Epidermal growth factor stimulates Rac activation through Src and phosphatidylinositol 3-kinase to promote colonic epithelial cell migration.

    PubMed

    Dise, Rebecca S; Frey, Mark R; Whitehead, Robert H; Polk, D Brent

    2008-01-01

    Regulated intestinal epithelial cell migration plays a key role in wound healing and maintenance of a healthy gastrointestinal tract. Epidermal growth factor (EGF) stimulates cell migration and wound closure in intestinal epithelial cells through incompletely understood mechanisms. In this study we investigated the role of the small GTPase Rac in EGF-induced cell migration using an in vitro wound-healing assay. In mouse colonic epithelial (MCE) cell lines, EGF-stimulated wound closure was accompanied by a doubling of the number of cells containing lamellipodial extensions at the wound margin, increased Rac membrane translocation in cells at the wound margin, and rapid Rac activation. Either Rac1 small interfering (si)RNA or a Rac1 inhibitor completely blocked EGF-stimulated wound closure. Whereas EGF failed to activate Rac in colon cells from EGF receptor (EGFR) knockout mice, stable expression of wild-type EGFR restored EGF-stimulated Rac activation and migration. Pharmacological inhibition of either phosphatidylinositol 3-kinase (PI3K) or Src family kinases reduced EGF-stimulated Rac activation. Cotreatment of cells with both inhibitors completely blocked EGF-stimulated Rac activation and localization to the leading edge of cells and lamellipodial extension. Our results present a novel mechanism by which the PI3K and Src signaling cascades cooperate to activate Rac and promote intestinal epithelial cell migration downstream of EGFR.

  4. Chloride Channel 3 Channels in the Activation and Migration of Human Blood Eosinophils in Allergic Asthma.

    PubMed

    Gaurav, Rohit; Bewtra, Againdra K; Agrawal, Devendra K

    2015-08-01

    Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is responsible for respiratory burst in immune cells. Chloride channel 3 (CLC3) has been linked to the respiratory burst in eosinophils and neutrophils. The effect of cytokines and the involvement of CLC3 in the regulation of NADPH-dependent oxidative stress and on cytokine-mediated migration of eosinophils are not known. Human peripheral blood eosinophils were isolated from healthy individuals and from individuals with asthma by negative selection. Real-time PCR was used to detect the expression of NADPH oxidases in eosinophils. Intracellular reactive oxygen species (ROS) measurement was done with flow cytometry. Superoxide generation was measured with transforming growth factor (TGF)-β, eotaxin, and CLC3 blockers. CLC3 dependence of eosinophils in TGF-β- and eotaxin-induced migration was also examined. The messenger RNA (mRNA) transcripts of NADPH oxidase (NOX) 2, dual oxidase (DUOX) 1, and DUOX2 were detected in blood eosinophils, with very low expression of NOX1, NOX3, and NOX5 and no NOX4 mRNA. The level of NOX2 mRNA transcripts increased with disease severity in the eosinophils of subjects with asthma compared with healthy nonatopic volunteers. Change in granularity and size in eosinophils, but no change in intracellular ROS, was observed with phorbol myristate acetate (PMA). PMA, TGF-β, and eotaxin used the CLC3-dependent pathway to increase superoxide radicals. TGF-β and eotaxin induced CLC3-dependent chemotaxis of eosinophils. These findings support the requirement of CLC3 in the activation and migration of human blood eosinophils and may provide a potential novel therapeutic target to regulate eosinophil hyperactivity in allergic airway inflammation in asthma.

  5. Macrophage Migration Inhibitory Factor Activates Hypoxia-Inducible Factor in a p53-Dependent Manner

    PubMed Central

    Oda, Seiko; Oda, Tomoyuki; Nishi, Kenichiro; Takabuchi, Satoshi; Wakamatsu, Takuhiko; Tanaka, Tomoharu; Adachi, Takehiko; Fukuda, Kazuhiko; Semenza, Gregg L.; Hirota, Kiichi

    2008-01-01

    Background Macrophage migration inhibitory factor (MIF) is not only a cytokine which has a critical role in several inflammatory conditions but also has endocrine and enzymatic functions. MIF is identified as an intracellular signaling molecule and is implicated in the process of tumor progression, and also strongly enhances neovascularization. Overexpression of MIF has been observed in tumors from various organs. MIF is one of the genes induced by hypoxia in an hypoxia-inducible factor 1 (HIF-1)-dependent manner. Methods/Principal Findings The effect of MIF on HIF-1 activity was investigated in human breast cancer MCF-7 and MDA-MB-231 cells, and osteosarcoma Saos-2 cells. We demonstrate that intracellular overexpression or extracellular administration of MIF enhances activation of HIF-1 under hypoxic conditions in MCF-7 cells. Mutagenesis analysis of MIF and knockdown of 53 demonstrates that the activation is not dependent on redox activity of MIF but on wild-type p53. We also indicate that the MIF receptor CD74 is involved in HIF-1 activation by MIF at least when MIF is administrated extracellularly. Conclusion/Significance MIF regulates HIF-1 activity in a p53-dependent manner. In addition to MIF's potent effects on the immune system, MIF is linked to fundamental processes conferring cell proliferation, cell survival, angiogenesis, and tumor invasiveness. This functional interdependence between MIF and HIF-1α protein stabilization and transactivation activity provide a molecular mechanism for promotion of tumorigenesis by MIF. PMID:18493321

  6. Borrelia burgdorferi Induces TLR2-Mediated Migration of Activated Dendritic Cells in an Ex Vivo Human Skin Model

    PubMed Central

    Wagemakers, Alex; van ‘t Veer, Cornelis; Oei, Anneke; van der Pot, Wouter J.; Ahmed, Kalam; van der Poll, Tom; Geijtenbeek, Teunis B. H.; Hovius, Joppe W. R.

    2016-01-01

    Borrelia burgdorferi is transmitted into the skin of the host where it encounters and interacts with two dendritic cell (DC) subsets; Langerhans cells (LCs) and dermal DCs (DDCs). These cells recognize pathogens via pattern recognition receptors, mature and migrate out of the skin into draining lymph nodes, where they orchestrate adaptive immune responses. In order to investigate the response of skin DCs during the early immunopathogenesis of Lyme borreliosis, we injected B. burgdorferi intradermally into full-thickness human skin and studied the migration of DCs out of the skin, the activation profile and phenotype of migrated cells. We found a significant increase in the migration of LCs and DDCs in response to B. burgdorferi. Notably, migration was prevented by blocking TLR2. DCs migrated from skin inoculated with higher numbers of spirochetes expressed significantly higher levels of CD83 and produced pro-inflammatory cytokines. No difference was observed in the expression of HLA-DR, CD86, CD38, or CCR7. To conclude, we have established an ex vivo human skin model to study DC-B. burgdorferi interactions. Using this model, we have demonstrated that B. burgdorferi-induced DC migration is mediated by TLR2. Our findings underscore the utility of this model as a valuable tool to study immunity to spirochetal infections. PMID:27695100

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

    PubMed

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

    2015-02-01

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

  8. Stopping the Slide: How Hospital Bed Design Can Minimize Active and Passive Patient Migration.

    PubMed

    Davis, Kermit G; Kotowski, Susan E; Coombs, Matthew T

    Patient migration, or the amount of movement toward the foot of the bed, has been shown to significantly vary because of the mechanical design differences in hospital beds. Previously, the amount of migration was measured immediately following head-of-bed articulation in healthy subjects. This study not only evaluates how much migration occurs immediately after head-of-bed articulation but also measures additional migration during a standard 2-hour repositioning period in subjects with limited mobility.

  9. Critical behavior of subcellular density organization during neutrophil activation and migration

    PubMed Central

    Baker-Groberg, Sandra M.; Phillips, Kevin G.; Healy, Laura D.; Itakura, Asako; Porter, Juliana E.; Newton, Paul K.; Nan, Xiaolin; McCarty, Owen J.T.

    2015-01-01

    Physical theories of active matter continue to provide a quantitative understanding of dynamic cellular phenomena, including cell locomotion. Although various investigations of the rheology of cells have identified important viscoelastic and traction force parameters for use in these theoretical approaches, a key variable has remained elusive both in theoretical and experimental approaches: the spatiotemporal behavior of the subcellular density. The evolution of the subcellular density has been qualitatively observed for decades as it provides the source of image contrast in label-free imaging modalities (e.g., differential interference contrast, phase contrast) used to investigate cellular specimens. While these modalities directly visualize cell structure, they do not provide quantitative access to the structures being visualized. We present an established quantitative imaging approach, non-interferometric quantitative phase microscopy, to elucidate the subcellular density dynamics in neutrophils undergoing chemokinesis following uniform bacterial peptide stimulation. Through this approach, we identify a power law dependence of the neutrophil mean density on time with a critical point, suggesting a critical density is required for motility on 2D substrates. Next we elucidate a continuum law relating mean cell density, area, and total mass that is conserved during neutrophil polarization and migration. Together, our approach and quantitative findings will enable investigators to define the physics coupling cytoskeletal dynamics with subcellular density dynamics during cell migration. PMID:26640599

  10. Phytoplankton can actively diversify their migration strategy in response to turbulent cues

    NASA Astrophysics Data System (ADS)

    Sengupta, Anupam; Carrara, Francesco; Stocker, Roman

    2017-03-01

    Marine phytoplankton inhabit a dynamic environment where turbulence, together with nutrient and light availability, shapes species fitness, succession and selection. Many species of phytoplankton are motile and undertake diel vertical migrations to gain access to nutrient-rich deeper layers at night and well-lit surface waters during the day. Disruption of this migratory strategy by turbulence is considered to be an important cause of the succession between motile and non-motile species when conditions turn turbulent. However, this classical view neglects the possibility that motile species may actively respond to turbulent cues to avoid layers of strong turbulence. Here we report that phytoplankton, including raphidophytes and dinoflagellates, can actively diversify their migratory strategy in response to hydrodynamic cues characteristic of overturning by Kolmogorov-scale eddies. Upon experiencing repeated overturning with timescales and statistics representative of ocean turbulence, an upward-swimming population rapidly (5–60 min) splits into two subpopulations, one swimming upward and one swimming downward. Quantitative morphological analysis of the harmful-algal-bloom-forming raphidophyte Heterosigma akashiwo together with a model of cell mechanics revealed that this behaviour was accompanied by a modulation of the cells’ fore–aft asymmetry. The minute magnitude of the required modulation, sufficient to invert the preferential swimming direction of the cells, highlights the advanced level of control that phytoplankton can exert on their migratory behaviour. Together with observations of enhanced cellular stress after overturning and the typically deleterious effects of strong turbulence on motile phytoplankton, these results point to an active adaptation of H. akashiwo to increase the chance of evading turbulent layers by diversifying the direction of migration within the population, in a manner suggestive of evolutionary bet-hedging. This migratory

  11. Zooplankton diel vertical migration and contribution to deep active carbon flux in the NW Mediterranean

    NASA Astrophysics Data System (ADS)

    Isla, Alejandro; Scharek, Renate; Latasa, Mikel

    2015-03-01

    The diel vertical migration (DVM) of zooplankton contributes to the biological pump transporting material from surface to deep waters. We examined the DVM of the zooplankton community in different size fractions (53-200 μm, 200-500 μm, 500-1000 μm, 1000-2000 μm and > 2000 μm) during three cruises carried out in the open NW Mediterranean Sea. We assessed their metabolic rates from empirical published relationships and estimated the active fluxes of dissolved carbon to the mesopelagic zone driven by migrant zooplankton. Within the predominantly oligotrophic Mediterranean Sea, the NW region is one of the most productive ones, with a seasonal cycle characterized by a prominent spring bloom. The study area was visited at three different phases of the seasonal cycle: during the spring bloom, the post-bloom, and strongly stratified oligotrophic conditions. We found seasonal differences in DVM, less evident during the bloom. Changes in DVM intensity were related to the composition of the zooplanktonic assemblage, which also varied between cruises. Euphausiids appeared as the most active migrants in all seasons, and their life cycle conditioned the observed pattern. Immature stages, which are unable to perform large diel vertical movements, dominated during the bloom, in contrast to the higher relative importance of migrating adults in the other two sampling periods. The amount of dissolved carbon exported was determined by the migrant zooplankton biomass, being highest during the post-bloom (2.2 mmol C respired m- 2 d- 1, and up to 3.1 mmol C exported m- 2 d- 1 when DOC release estimations are added). The active transport by diel migrants represented a substantial contribution to total carbon export to deep waters, especially under stratified oligotrophic conditions, revealing the importance of zooplankton in the biological pump operating in the study area.

  12. Tracking a defined route for O₂ migration in a dioxygen-activating diiron enzyme.

    PubMed

    Song, Woon Ju; Gucinski, Grant; Sazinsky, Matthew H; Lippard, Stephen J

    2011-09-06

    For numerous enzymes reactive toward small gaseous compounds, growing evidence indicates that these substrates diffuse into active site pockets through defined pathways in the protein matrix. Toluene/o-xylene monooxygenase hydroxylase is a dioxygen-activating enzyme. Structural analysis suggests two possible pathways for dioxygen access through the α-subunit to the diiron center: a channel or a series of hydrophobic cavities. To distinguish which is utilized as the O(2) migration pathway, the dimensions of the cavities and the channel were independently varied by site-directed mutagenesis and confirmed by X-ray crystallography. The rate constants for dioxygen access to the diiron center were derived from the formation rates of a peroxodiiron(III) intermediate, generated upon treatment of the diiron(II) enzyme with O(2). This reaction depends on the concentration of dioxygen to the first order. Altering the dimensions of the cavities, but not the channel, changed the rate of dioxygen reactivity with the enzyme. These results strongly suggest that voids comprising the cavities in toluene/o-xylene monooxygenase hydroxylase are not artifacts of protein packing/folding, but rather programmed routes for dioxygen migration through the protein matrix. Because the cavities are not fully connected into the diiron active center in the enzyme resting state, conformational changes will be required to facilitate dioxygen access to the diiron center. We propose that such temporary opening and closing of the cavities may occur in all bacterial multicomponent monooxygenases to control O(2) consumption for efficient catalysis. Our findings suggest that other gas-utilizing enzymes may employ similar structural features to effect substrate passage through a protein matrix.

  13. Enhancement of endothelial cell migration by constitutively active LPA{sub 1}-expressing tumor cells

    SciTech Connect

    Kitayoshi, Misaho; Kato, Kohei; Tanabe, Eriko; Yoshikawa, Kyohei; Fukui, Rie; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2012-06-01

    Highlights: Black-Right-Pointing-Pointer Mutated LPA{sub 1} stimulates cell migration of endothelial cells. Black-Right-Pointing-Pointer VEGF expressions are increased by mutated LPA{sub 1}. Black-Right-Pointing-Pointer LPA signaling via mutated LPA{sub 1} is involved in angiogenesis. Black-Right-Pointing-Pointer Mutated LPA{sub 1} promotes cancer cell progression. -- Abstract: Lysophosphatidic acid (LPA) receptors belong to G protein-coupled transmembrane receptors (LPA receptors; LPA{sub 1} to LPA{sub 6}). They indicate a variety of cellular response by the interaction with LPA, including cell proliferation, migration and differentiation. Recently, we have reported that constitutive active mutated LPA{sub 1} induced the strong biological effects of rat neuroblastoma B103 cells. In the present study, we examined the effects of mutated LPA{sub 1} on the interaction between B103 cells and endothelial F-2 cells. Each LPA receptor expressing B103 cells were maintained in serum-free DMEM and cell motility assay was performed with a Cell Culture Insert. When F-2 cells were cultured with conditioned medium from Lpar1 and Lpar3-expressing cells, the cell motility of F-2 cells was significantly higher than control cells. Interestingly, the motile activity of F-2 cells was strongly induced by mutated LPA{sub 1} than other cells, correlating with the expression levels of vascular endothelial growth factor (Vegf)-A and Vegf-C. Pretreatment of LPA signaling inhibitors inhibited F-2 cell motility stimulated by mutated LPA{sub 1}. These results suggest that activation of LPA signaling via mutated LPA{sub 1} may play an important role in the promotion of angiogenesis in rat neuroblastoma cells.

  14. Ena/VASP proteins regulate activated T-cell trafficking by promoting diapedesis during transendothelial migration.

    PubMed

    Estin, Miriam L; Thompson, Scott B; Traxinger, Brianna; Fisher, Marlie H; Friedman, Rachel S; Jacobelli, Jordan

    2017-04-04

    Vasodilator-stimulated phosphoprotein (VASP) and Ena-VASP-like (EVL) are cytoskeletal effector proteins implicated in regulating cell morphology, adhesion, and migration in various cell types. However, the role of these proteins in T-cell motility, adhesion, and in vivo trafficking remains poorly understood. This study identifies a specific role for EVL and VASP in T-cell diapedesis and trafficking. We demonstrate that EVL and VASP are selectively required for activated T-cell trafficking but are not required for normal T-cell development or for naïve T-cell trafficking to lymph nodes and spleen. Using a model of multiple sclerosis, we show an impairment in trafficking of EVL/VASP-deficient activated T cells to the inflamed central nervous system of mice with experimental autoimmune encephalomyelitis. Additionally, we found a defect in trafficking of EVL/VASP double-knockout (dKO) T cells to the inflamed skin and secondary lymphoid organs. Deletion of EVL and VASP resulted in the impairment in α4 integrin (CD49d) expression and function. Unexpectedly, EVL/VASP dKO T cells did not exhibit alterations in shear-resistant adhesion to, or in crawling on, primary endothelial cells under physiologic shear forces. Instead, deletion of EVL and VASP impaired T-cell diapedesis. Furthermore, T-cell diapedesis became equivalent between control and EVL/VASP dKO T cells upon α4 integrin blockade. Overall, EVL and VASP selectively mediate activated T-cell trafficking by promoting the diapedesis step of transendothelial migration in a α4 integrin-dependent manner.

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

    PubMed Central

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

    2008-01-01

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

  16. Structural and Kinetic Analyses of Macrophage Migration Inhibitory Factor Active Site Interactions

    SciTech Connect

    Crichlow, G.; Lubetsky, J; Leng, L; Bucala, R; Lolis, E

    2009-01-01

    Macrophage migration inhibitory factor (MIF) is a secreted protein expressed in numerous cell types that counters the antiinflammatory effects of glucocorticoids and has been implicated in sepsis, cancer, and certain autoimmune diseases. Interestingly, the structure of MIF contains a catalytic site resembling the tautomerase/isomerase sites of microbial enzymes. While bona fide physiological substrates remain unknown, model substrates have been identified. Selected compounds that bind in the tautomerase active site also inhibit biological functions of MIF. It had previously been shown that the acetaminophen metabolite, N-acetyl-p-benzoquinone imine (NAPQI), covalently binds to the active site of MIF. In this study, kinetic data indicate that NAPQI inhibits MIF both covalently and noncovalently. The structure of MIF cocrystallized with NAPQI reveals that the NAPQI has undergone a chemical alteration forming an acetaminophen dimer (bi-APAP) and binds noncovalently to MIF at the mouth of the active site. We also find that the commonly used protease inhibitor, phenylmethylsulfonyl fluoride (PMSF), forms a covalent complex with MIF and inhibits the tautomerase activity. Crystallographic analysis reveals the formation of a stable, novel covalent bond for PMSF between the catalytic nitrogen of the N-terminal proline and the sulfur of PMSF with complete, well-defined electron density in all three active sites of the MIF homotrimer. Conclusions are drawn from the structures of these two MIF-inhibitor complexes regarding the design of novel compounds that may provide more potent reversible and irreversible inhibition of MIF.

  17. Investigations of the potential effects of underwater noise from petroleum-industry activities on migrating gray-whale behavior. Phase 2: January 1984 migration

    SciTech Connect

    Malme, C.I.; Miles, P.R.; Clark, C.W.; Tyack, P.; Bird, J.E.

    1984-08-01

    The study supplements work performed during 1983 in the Monterey, California region in determining the degree of behavioral response of migrating gray whales to acoustic stimuli associated with oil and gas exploration and development activities. A computer-implemented trackline program analyzed the theodolite data for any possible changes in distance from shore, speed, linearity of track, orientation toward the sound source, and course heading of the whale group. A history of marine seismic exploration off California was compiled that showed no long-term relationship with growth rates in the gray whale population.

  18. cAMP-induced Epac-Rap activation inhibits epithelial cell migration by modulating focal adhesion and leading edge dynamics.

    PubMed

    Lyle, Karen S; Raaijmakers, Judith H; Bruinsma, Wytse; Bos, Johannes L; de Rooij, Johan

    2008-06-01

    Epithelial cell migration is a complex process crucial for embryonic development, wound healing and tumor metastasis. It depends on alterations in cell-cell adhesion and integrin-extracellular matrix interactions and on actomyosin-driven, polarized leading edge protrusion. The small GTPase Rap is a known regulator of integrins and cadherins that has also been implicated in the regulation of actin and myosin, but a direct role in cell migration has not been investigated. Here, we report that activation of endogenous Rap by cAMP results in an inhibition of HGF- and TGFbeta-induced epithelial cell migration in several model systems, irrespective of the presence of E-cadherin adhesion. We show that Rap activation slows the dynamics of focal adhesions and inhibits polarized membrane protrusion. Importantly, forced integrin activation by antibodies does not mimic these effects of Rap on cell motility, even though it does mimic Rap effects in short-term cell adhesion assays. From these results, we conclude that Rap inhibits epithelial cell migration, by modulating focal adhesion dynamics and leading edge activity. This extends beyond the effect of integrin affinity modulation and argues for an additional function of Rap in controlling the migration machinery of epithelial cells.

  19. Role of low voltage activated calcium channels in neuritogenesis and active migration of embryonic neural progenitor cells.

    PubMed

    Louhivuori, Lauri M; Louhivuori, Verna; Wigren, Henna-Kaisa; Hakala, Elina; Jansson, Linda C; Nordström, Tommy; Castrén, Maija L; Akerman, Karl E

    2013-04-15

    The central role of calcium influx and electrical activity in embryonic development raises important questions about the role and regulation of voltage-dependent calcium influx. Using cultured neural progenitor cell (NPC) preparations, we recorded barium currents through voltage-activated channels using the whole-cell configuration of the patch-clamp technique and monitored intracellular free calcium concentrations with Fura-2 digital imaging. We found that NPCs as well as expressing high-voltage-activated (HVA) calcium channels express functional low-threshold voltage-dependent calcium channels in the very early stages of differentiation (5 h to 1 day). The size of the currents recorded at -50 versus -20 mV after 1 day in differentiation was dependent on the nature of the charge carrier. Peak currents measured at -20 mV in the presence 10 mM Ca2+ instead of 10 mM Ba2+ had a tendency to be smaller, whereas the nature of the divalent species did not influence the amplitude measured at -50 mV. The T-type channel blockers mibefradil and NNC 55-0396 significantly reduced the calcium responses elicited by depolarizing with extracellular potassium, while the overall effect of the HVA calcium channel blockers was small at differentiation day 1. At differentiation day 20, the calcium responses were effectively blocked by nifedipine. Time-lapse imaging of differentiating neurospheres cultured in the presence of low-voltage-activated (LVA) blockers showed a significant decrease in the number of active migrating neuron-like cells and neurite extensions. Together, these data provide evidence that LVA calcium channels are involved in the physiology of differentiating and migrating NPCs.

  20. Perfluorooctanoic acid induces human Ishikawa endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling

    PubMed Central

    Li, Fujun; Wang, Yixong; Xu, Yang; Zhang, Mei; Zhang, Xiaoqian; Ying, Xiaoyan; Zhang, Xuesen

    2016-01-01

    Perfluorooctanoic acid (PFOA) is a common environmental pollutant that has been associated with various diseases, including cancer. We explored the molecular mechanisms underlying PFOA-induced endometrial cancer cell invasion and migration. PFOA treatment enhanced migration and invasion by human Ishikawa endometrial cancer cells, which correlated with decreased E-cadherin expression, a marker of epithelial-mesenchymal transition. PFOA also induced activation of ERK1/2/mTOR signaling. Treatment with rapamycin, an mTOR inhibitor, antagonized the effects of PFOA and reversed the effects of PFOA activation in a xenograft mouse model of endometrial cancer. Consistent with these results, pre-treatment with rapamycin abolished PFOA-induced down-regulation of E-cadherin expression. These results indicate that PFOA is a carcinogen that promotes endometrial cancer cell migration and invasion through activation of ERK/mTOR signaling. PMID:27589685

  1. HMG-CoA reductase regulates CCL17-induced colon cancer cell migration via geranylgeranylation and RhoA activation

    SciTech Connect

    Al-Haidari, Amr A.; Syk, Ingvar; Thorlacius, Henrik

    2014-03-28

    Highlights: • Simvastatin blocked CCL17-induced and CCR4-dependent RhoA activation in HT29 cells. • CCL17/CCR4-mediated migration of colon cancer cells was antagonised by simvastatin. • Cell migration recovered by adding Mevalonate and geranylgeranyl pyrophosphate. • Targeting HMG-CoA reductase might be useful to inhibit colon cancer metastasis. - Abstract: Background: Simvastatin is widely used to lower cholesterol levels in patients with cardiovascular diseases, although accumulating evidence suggests that statins, such as simvastatin, also exert numerous anti-tumoral effects. Aim: The aim of this study was to examine the effect of simvastatin on colon cancer cell migration. Methods: Migration assays were performed to evaluate CCL17-induced colon cancer cell (HT-29) chemotaxis. In vitro tumor growth and apoptosis were assessed using a proliferation assay and annexin V assay, respectively. Active RhoA protein levels in CCL17-stimulated colon cancer cells were quantified using a G-LISA assay. Results: We found that simvastatin dose-dependently decreased CCL17-induced colon cancer cell migration. Simvastatin had no effect on colon cancer cell proliferation or apoptosis. Inhibition of beta chemokine receptor 4, CCR4, reduced CCL17-evoked activation of RhoA in colon cancer cells. Moreover, administration of mevalonate reversed the inhibitory effect of simvastatin on CCL17-induced colon cancer cell migration. Interestingly, co-incubation with geranylgeranyl pyrophosphate (GGPP) antagonized the inhibitory impact of simvastatin on colon cancer cell migration triggered by CCL17. Moreover, we observed that simvastatin decreased CCL17-induced activation of RhoA in colon cancer cells. Administration of mevalonate and GGPP reversed the inhibitory effect of simvastatin on CCL17-provoked RhoA activation in colon cancer cells. Conclusions: Taken together, our findings show for the first time that HMG-CoA reductase regulates CCL17-induced colon cancer cell migration via

  2. Age, habitat and tide effects on feeding activity of Emperor Geese during Autumn migration

    USGS Publications Warehouse

    Schmutz, Joel A.

    1994-01-01

    I studied feeding activity of Emperor Geese (Chen canagica) on the Alaska Peninsula during autumn migration, 1991. Scan samples were used to estimate the proportion of birds feeding in flocks as a measure of feeding intensity. Most geese fed during low tides and roosted during high tides. However, flocks with disproportionately more juveniles continued to feed during high tides in either blue mussel (Mytilus edulis) beds (during relatively low high tides) or in vegetated habitats. Feeding intensity was higher in mussel habitats than in mud/sand or vegetated habitats, and juveniles fed more than adults. Juvenile geese probably have greater nutritional needs than adults, and feeding during high tide may represent their attempt to satisfy these disproportionate demands. Vegetated habitats may be used when high value bivalve prey are unavailable due to tidal inundation.

  3. Regulator of G protein signaling 1 suppresses CXCL12-mediated migration and AKT activation in RPMI 8226 human plasmacytoma cells and plasmablasts.

    PubMed

    Pak, Hyo-Kyung; Gil, Minchan; Lee, Yoonkyung; Lee, Hyunji; Lee, A-Neum; Roh, Jin; Park, Chan-Sik

    2015-01-01

    Migration of plasma cells to the bone marrow is critical factor to humoral immunity and controlled by chemokines. Regulator of G protein signaling 1 (RGS1) is a GTPase-activating protein that controls various crucial functions such as migration. Here, we show that RGS1 controls the chemotactic migration of RPMI 8226 human plasmacytoma cells and human plasmablasts. LPS strongly increased RGS1 expression and retarded the migration of RPMI 8226 cells by suppressing CXCL12-mediated AKT activation. RGS1 knockdown by siRNA abolished the retardation of migration and AKT suppression by LPS. RGS1-dependent regulation of migration via AKT is also observed in cultured plasmablasts. We propose novel functions of RGS1 that suppress AKT activation and the migration of RPMI 8226 cells and plasmablasts in CXCL12-mediated chemotaxis.

  4. Human single-chain variable fragment antibody inhibits macrophage migration inhibitory factor tautomerase activity.

    PubMed

    Tarasuk, Mayuri; Poungpair, Ornnuthchar; Ungsupravate, Duangporn; Bangphoomi, Kunan; Chaicumpa, Wanpen; Yenchitsomanus, Pa-Thai

    2014-03-01

    Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine, secreted from a variety of immune cells, that regulates innate and adaptive immune responses. Elevation of MIF levels in plasma correlates with the severity of inflammatory diseases in humans. Inhibition of MIF or its tautomerase activity ameliorates disease severity by reducing inflammatory responses. In this study, the human single-chain variable fragment (HuScFv) antibody specific to MIF was selected from the human antibody phage display library by using purified recombinant full-length human MIF (rMIF) as the target antigen. Monoclonal HuScFv was produced from phage-transformed bacteria and tested for their binding activities to rMIF by indirect enzyme-linked immunosorbent assay as well as to native MIF by western blot analysis and immunofluorescence assay. The HuScFv with highest binding signal to rMIF also inhibited the tautomerase activities of both rMIF and native MIF in human monoblastic leukemia (U937) cells in a dose-dependent manner. Mimotope searching and molecular docking concordantly demonstrated that the HuScFv interacted with Lys32 and Ile64 in the MIF tautomerase active site. To the best of our knowledge, this is the first study to focus on MIF-specific fully-human antibody fragment with a tautomerase-inhibitory effect that has potential to be developed as anti-inflammatory biomolecules for human use.

  5. Elk migration patterns and human activity influence wolf habitat use in the Greater Yellowstone Ecosystem.

    PubMed

    Nelson, Abigail A; Kauffman, Matthew J; Middleton, Arthur D; Jimenez, Michael D; McWhirter, Douglas E; Barber, Jarrett; Gerow, Kenneth

    2012-12-01

    Identifying the ecological dynamics underlying human-wildlife conflicts is important for the management and conservation of wildlife populations. In landscapes still occupied by large carnivores, many ungulate prey species migrate seasonally, yet little empirical research has explored the relationship between carnivore distribution and ungulate migration strategy. In this study, we evaluate the influence of elk (Cervus elaphus) distribution and other landscape features on wolf (Canis lupus) habitat use in an area of chronic wolf-livestock conflict in the Greater Yellowstone Ecosystem, USA. Using three years of fine-scale wolf (n = 14) and elk (n = 81) movement data, we compared the seasonal habitat use of wolves in an area dominated by migratory elk with that of wolves in an adjacent area dominated by resident elk. Most migratory elk vacate the associated winter wolf territories each summer via a 40-60 km migration, whereas resident elk remain accessible to wolves year-round. We used a generalized linear model to compare the relative probability of wolf use as a function of GIS-based habitat covariates in the migratory and resident elk areas. Although wolves in both areas used elk-rich habitat all year, elk density in summer had a weaker influence on the habitat use of wolves in the migratory elk area than the resident elk area. Wolves employed a number of alternative strategies to cope with the departure of migratory elk. Wolves in the two areas also differed in their disposition toward roads. In winter, wolves in the migratory elk area used habitat close to roads, while wolves in the resident elk area avoided roads. In summer, wolves in the migratory elk area were indifferent to roads, while wolves in resident elk areas strongly avoided roads, presumably due to the location of dens and summering elk combined with different traffic levels. Study results can help wildlife managers to anticipate the movements and establishment of wolf packs as they expand into areas

  6. Elk migration patterns and human activity influence wolf habitat use in the Greater Yellowstone Ecosystem

    USGS Publications Warehouse

    Nelson, Abigail; Kauffman, Matthew J.; Middleton, Arthur D.; Jimenez, Mike; McWhirter, Douglas; Barber, Jarrett; Gerow, Ken

    2012-01-01

    Identifying the ecological dynamics underlying human–wildlife conflicts is important for the management and conservation of wildlife populations. In landscapes still occupied by large carnivores, many ungulate prey species migrate seasonally, yet little empirical research has explored the relationship between carnivore distribution and ungulate migration strategy. In this study, we evaluate the influence of elk (Cervus elaphus) distribution and other landscape features on wolf (Canis lupus) habitat use in an area of chronic wolf–livestock conflict in the Greater Yellowstone Ecosystem, USA. Using three years of fine-scale wolf (n = 14) and elk (n = 81) movement data, we compared the seasonal habitat use of wolves in an area dominated by migratory elk with that of wolves in an adjacent area dominated by resident elk. Most migratory elk vacate the associated winter wolf territories each summer via a 40–60 km migration, whereas resident elk remain accessible to wolves year-round. We used a generalized linear model to compare the relative probability of wolf use as a function of GIS-based habitat covariates in the migratory and resident elk areas. Although wolves in both areas used elk-rich habitat all year, elk density in summer had a weaker influence on the habitat use of wolves in the migratory elk area than the resident elk area. Wolves employed a number of alternative strategies to cope with the departure of migratory elk. Wolves in the two areas also differed in their disposition toward roads. In winter, wolves in the migratory elk area used habitat close to roads, while wolves in the resident elk area avoided roads. In summer, wolves in the migratory elk area were indifferent to roads, while wolves in resident elk areas strongly avoided roads, presumably due to the location of dens and summering elk combined with different traffic levels. Study results can help wildlife managers to anticipate the movements and establishment of wolf packs as they expand into

  7. Soluble tissue factor has unique angiogenic activities that selectively promote migration and differentiation but not proliferation of endothelial cells

    SciTech Connect

    He Yingbo; Chang Guodong; Zhan Shunli; Song Xiaomin; Wang Xiaofeng; Luo Yongzhang

    2008-06-06

    The level of circulating tissue factor (TF) is up-regulated in human angiogenesis-related malignancies. However, whether circulating TF has angiogenic activities has not been determined. Soluble TF (sTF) is the main domain of circulating TF. Here, using cell migration, wound healing, and tubule formation assays, human recombinant sTF was found to significantly promote the migration and differentiation of endothelial cells. The stress fiber formation and rearrangement induced by sTF observed through immunofluorescence microscope may be responsible for the stimulatory migration effect of sTF. Nevertheless, sTF had no effects on endothelial cell proliferation. Interestingly, sTF can be internalized by endothelial cells, which implies a novel mechanism for sTF in angiogenesis. These results suggest that sTF has unique angiogenic activities and may serve as a potential therapeutic target to treat diseases associated with angiogenesis such as cancer and rheumatoid arthritis.

  8. Minimal model for spontaneous cell polarization and edge activity in oscillating, rotating and migrating cells

    NASA Astrophysics Data System (ADS)

    Raynaud, Franck; Ambühl, Mark E.; Gabella, Chiara; Bornert, Alicia; Sbalzarini, Ivo F.; Meister, Jean-Jacques; Verkhovsky, Alexander B.

    2016-04-01

    How cells break symmetry and organize activity at their edges to move directionally is a fundamental question in cell biology. Physical models of cell motility commonly incorporate gradients of regulatory proteins and/or feedback from the motion itself to describe the polarization of this edge activity. These approaches, however, fail to explain cell behaviour before the onset of polarization. We use polarizing and moving fish epidermal cells as a model system to bridge the gap between cell behaviours before and after polarization. Our analysis suggests a novel and simple principle of self-organizing cell activity, in which local cell-edge dynamics depends on the distance from the cell centre, but not on the orientation with respect to the front-back axis. We validate this principle with a stochastic model that faithfully reproduces a range of cell-migration behaviours. Our findings indicate that spontaneous polarization, persistent motion and cell shape are emergent properties of the local cell-edge dynamics controlled by the distance from the cell centre.

  9. A novel signaling pathway of tissue kallikrein in promoting keratinocyte migration: Activation of proteinase-activated receptor 1 and epidermal growth factor receptor

    SciTech Connect

    Gao, Lin; Chao, Lee; Chao, Julie

    2010-02-01

    Biological functions of tissue kallikrein (TK, KLK1) are mainly mediated by kinin generation and subsequent kinin B2 receptor activation. In this study, we investigated the potential role of TK and its signaling pathways in cultured human keratinocyte migration and in a rat skin wound healing model. Herein, we show that TK promoted cell migration and proliferation in a concentration- and time-dependent manner. Inactive TK or kinin had no significant effect on cell migration. Interestingly, cell migration induced by active TK was not blocked by icatibant or L-NAME, indicating an event independent of kinin B2 receptor and nitric oxide formation. TK's stimulatory effect on cell migration was inhibited by small interfering RNA for proteinase-activated receptor 1 (PAR{sub 1}), and by PAR{sub 1} inhibitor. TK-induced migration was associated with increased phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK), which was blocked by inhibition of protein kinase C (PKC), Src, EGFR and ERK. TK-induced cell migration and EGFR phosphorylation were blocked by metalloproteinase (MMP) inhibitor, heparin, and antibodies against EGFR external domain, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AR). Local application of TK promoted skin wound healing in rats, whereas icatibant and EGFR inhibitor blocked TK's effect. Skin wound healing was further delayed by aprotinin and neutralizing TK antibody. This study demonstrates a novel role of TK in skin wound healing and uncovers new signaling pathways mediated by TK in promoting keratinocyte migration through activation of the PAR{sub 1}-PKC-Src-MMP pathway and HB-EGF/AR shedding-dependent EGFR transactivation.

  10. Monarch Migration.

    ERIC Educational Resources Information Center

    Williamson, Brad; Taylor, Orley

    1996-01-01

    Describes the Monarch Watch program that tracks the migration of the monarch butterfly. Presents activities that introduce students to research and international collaboration between students and researchers. Familiarizes students with monarchs, stimulates their interest, and helps them generate questions that can lead to good research projects.…

  11. Piperlongumine Inhibits Migration of Glioblastoma Cells via Activation of ROS-Dependent p38 and JNK Signaling Pathways

    PubMed Central

    Liu, Qian Rong; Liu, Ju Mei; Chen, Yong; Xie, Xiao Qiang; Xiong, Xin Xin; Qiu, Xin Yao; Pan, Feng; Liu, Di; Yu, Shang Bin; Chen, Xiao Qian

    2014-01-01

    Piperlongumine (PL) is recently found to kill cancer cells selectively and effectively via targeting reactive oxygen species (ROS) responses. To further explore the therapeutic effects of PL in cancers, we investigated the role and mechanisms of PL in cancer cell migration. PL effectively inhibited the migration of human glioma (LN229 or U87 MG) cells but not normal astrocytes in the scratch-wound culture model. PL did not alter EdU+-cells and cdc2, cdc25c, or cyclin D1 expression in our model. PL increased ROS (measured by DCFH-DA), reduced glutathione, activated p38 and JNK, increased IκBα, and suppressed NFκB in LN229 cells after scratching. All the biological effects of PL in scratched LN229 cells were completely abolished by the antioxidant N-acetyl-L-cysteine (NAC). Pharmacological administration of specific p38 (SB203580) or JNK (SP600125) inhibitors significantly reduced the inhibitory effects of PL on LN229 cell migration and NFκB activity in scratch-wound and/or transwell models. PL prevented the deformation of migrated LN229 cells while NAC, SB203580, or SP600125 reversed PL-induced morphological changes of migrated cells. These results suggest potential therapeutic effects of PL in the treatment and prevention of highly malignant tumors such as glioblastoma multiforme (GBM) in the brain by suppressing tumor invasion and metastasis. PMID:24967005

  12. Neutrophil migration across monolayers of cytokine-prestimulated endothelial cells: a role for platelet-activating factor and IL-8

    PubMed Central

    1992-01-01

    In a previous study we observed that neutrophils respond with a rapid rise in [Ca2+]i during adherence to cytokine-activated endothelial cells (EC), caused by EC membrane-associated platelet-activating factor (PAF). In the present study, we investigated whether this form of PAF was important in neutrophil adherence and migration across monolayers of rIL-1 beta- or rTNF alpha-prestimulated EC. PAF receptor antagonists prevented neutrophil migration across cytokine-pretreated EC by approximately 60% (P less than 0.005) without interfering with the process of adherence. The antagonists WEB 2086 and L-652,731 had no effect on neutrophil migration across resting EC induced by formylmethionyl-leucyl-phenylalanine (FMLP). A murine anti-IL-8 antiserum was found to also partially inhibit the neutrophil transmigration across cytokine-activated EC. When the anti-IL-8 antiserum was used in combination with a PAF receptor antagonist, neutrophil migration across cytokine-pretreated monolayers of EC was completely prevented. During transmigration, LAM-1 and CD44 on the neutrophils were down-modulated; both WEB 2086 and anti-IL-8 antiserum partially prevented this down-modulation caused by cytokine- prestimulated EC. Our results indicate that human neutrophils are activated and guided by EC-associated PAF and EC-derived IL-8 during the in vitro diapedesis in between cytokine-stimulated EC. PMID:1315317

  13. Morinda citrifolia Linn leaf extract possesses antioxidant activities and reduces nociceptive behavior and leukocyte migration.

    PubMed

    Serafini, Mairim Russo; Santos, Rodrigo Correia; Guimarães, Adriana Gibara; Dos Santos, João Paulo Almeida; da Conceicão Santos, Alan Diego; Alves, Izabel Almeida; Gelain, Daniel Pens; de Lima Nogueira, Paulo Cesar; Quintans-Júnior, Lucindo José; Bonjardim, Leonardo Rigoldi; de Souza Araújo, Adriano Antunes

    2011-10-01

    Herbal drugs have been used since ancient times to treat a wide range of diseases. Morinda citrifolia Linn (popularly known as "Noni") has been used in folk medicine by Polynesians for over 2,000 years. It is reported to have a broad range of therapeutic effects, including effects against headache, fever, arthritis, gingivitis, respiratory disorders, infections, tuberculosis, and diabetes. The aim of this study was to investigate the antioxidant, anti-inflammatory, antinociceptive, and antibacterial properties of the aqueous extract from M. citrifolia leaves (AEMC). Antioxidant activity was observed against lipid peroxidation, nitric oxide, and hydroxyl radicals. The antinociceptive effect of AEMC was observed in the acetic acid-induced writhing test at the higher dose. Moreover, AEMC significantly reduced the leukocyte migration in doses of 200 and 400 mg/kg and showed mild antibacterial activity. Together, the results suggest that properties of M. citrifolia leaf extract should be explored further in order to achieve newer tools for managing painful and inflammation conditions, including those related to oxidant states.

  14. Macrophage Migration Inhibitory Factor (MIF): Biological Activities and Relation with Cancer.

    PubMed

    Nobre, Camila Cristina Guimarães; de Araújo, Josélio Maria Galvão; Fernandes, Thales Allyrio Araújo de Medeiros; Cobucci, Ricardo Ney Oliveira; Lanza, Daniel Carlos Ferreira; Andrade, Vânia Sousa; Fernandes, José Veríssimo

    2016-10-23

    Macrophage migration inhibitory factor (MIF) emerged in recent years as an important inflammation mediator, playing a prominent role in the pathogenesis of various types of malignant neoplasm. MIF is a glycoprotein that presents a wide spectrum of biological activities and exerts a complex interaction with various cellular signaling pathways, causing imbalance of homeostasis. Experimental and clinical studies show that high levels of MIF are found in almost all types of human cancers and are implicated in seemingly all stages of development of the tumors. The production of MIF is triggered through an autocrine signal emitted by tumor cells, and stimulates the production of cytokines, chemokines, and growth as well as angiogenic factors that lead to growth of the tumor, increasing its aggressiveness and metastatic potential. MIF is produced by virtually all types of human body cells, in response to stress caused by different factors, leading to pathological conditions such as chronic inflammation and immunomodulation with suppression of immune surveillance and of immune response against tumors, angiogenesis, and carcinogenesis. In this review, we present recent advances on the biological activity of MIF, the signaling pathways with which it is involved and their role in tumorigenesis.

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

    PubMed

    Naik, Ulhas P; Naik, Meghna U

    2008-01-01

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

  16. Influence of polymer matrix and adsorption onto silica materials on the migration of alpha-tocopherol into 95% ethanol from active packaging.

    PubMed

    Heirlings, L; Siró, I; Devlieghere, F; Van Bavel, E; Cool, P; De Meulenaer, B; Vansant, E F; Debevere, J

    2004-11-01

    In this study, the effect of polymer materials with different polarity, namely low density polyethylene (LDPE) and ethylene vinyl acetate (EVA), on the migration behaviour of alpha-tocopherol from active packaging was investigated. The antioxidant was also adsorbed onto silica materials, namely SBA-15 (Santa Barbara-15) and Syloblock, in order to protect the antioxidant during extrusion and to ensure a controlled and sufficient release during the shelf-life of the food product. Migration experiments were performed at 7.0 +/- 0.5 degrees C and 95% ethanol was used as fatty food simulant. All films contained a high concentration of alpha-tocopherol, approximately 2000 mg kg(-1), to obtain an active packaging. Polymer matrix had a small influence on the migration profile. The migration of 80% of total migrated amount of antioxidant was retarded for 2.4 days by using LDPE instead of EVA. When alpha-tocopherol was adsorbed onto both silica materials, the migration of 80% of total migrated amount of antioxidant was retarded for 3.4 days in comparison to pure alpha-tocopherol. No difference was seen between the migration profiles of alpha-tocopherol adsorbed onto both silica materials. In the case of pure alpha-tocopherol, 82% of the initial amount of alpha-tocopherol in the film migrated into the food simulant at a rather fast migration rate. In the case of adsorption on silica materials, a total migration was observed. These antioxidative films can have positive food applications.

  17. Interactions between interleukin-2-activated lymphocytes and vascular endothelium: binding to and migration across specialized and non-specialized endothelia.

    PubMed Central

    Pankonin, G; Reipert, B; Ager, A

    1992-01-01

    A prerequisite for the successful immunotherapy of solid tumours with interleukin-2 (IL-2)-activated lymphocytes is their ability to home to the tumour tissue. Lymphocyte homing is a complex process which is known to involve at least two independently regulated events: adhesion to the luminal surface of vascular endothelium and the subsequent transendothelial migration of lymphocytes. In this study we have used an in vitro model of lymphocyte homing which employs specialized high endothelium to ask whether IL-2-activated lymphocytes are able to migrate across vascular endothelium in order to leave the blood vessel. Both the adhesion of IL-2-activated cells and their migration across monolayers of cultured high endothelial cells (HEC) were increased in comparison with non-activated lymphocytes. The adhesion of IL-2-activated lymphocytes was mediated by lymphocyte function-associated antigen-1 (LFA-1) and a very late activation antigen-4 (VLA-4)-related pathway. LFA-1-dependent adhesion was mediated by ligands on HEC other than the intercellular adhesion molecule-1 (ICAM-1) and the VLA-4-related pathway was mediated by ligands other than the CS1 domain of fibronectin. HEC-adherent lymphocytes were enriched in natural killer (NK) cells and CD8+ T cells which are known to be the tumour-cytotoxic cells in IL-2-activated lymphocytes. However, there was no evidence of cytotoxicity towards the endothelial layer using a syngeneic model. The interaction of IL-2-activated lymphocytes and endothelial cells was not specific for high endothelium since equal numbers of activated lymphocytes bound to and migrated across aortic endothelium. The inability of IL-2-activated lymphocytes to discriminate between high endothelium and non-specialized 'flat' endothelium could be responsible for the widespread dissemination of the cells throughout the body following their adoptive transfer and the unwanted side-effects at non-involved sites. Images Figure 2 PMID:1398764

  18. Low-Dose Curcumin Stimulates Proliferation, Migration and Phagocytic Activity of Olfactory Ensheathing Cells

    PubMed Central

    Tello Velasquez, Johana; Watts, Michelle E.; Todorovic, Michael; Nazareth, Lynnmaria; Pastrana, Erika; Diaz-Nido, Javier; Lim, Filip; Ekberg, Jenny A. K.; Quinn, Ronald J.; John, James A. St

    2014-01-01

    One of the promising strategies for neural repair therapies is the transplantation of olfactory ensheathing cells (OECs) which are the glial cells of the olfactory system. We evaluated the effects of curcumin on the behaviour of mouse OECs to determine if it could be of use to further enhance the therapeutic potential of OECs. Curcumin, a natural polyphenol compound found in the spice turmeric, is known for its anti-cancer properties at doses over 10 µM, and often at 50 µM, and it exerts its effects on cancer cells in part by activation of MAP kinases. In contrast, we found that low-dose curcumin (0.5 µM) applied to OECs strikingly modulated the dynamic morphology, increased the rate of migration by up to 4-fold, and promoted significant proliferation of the OECs. Most dramatically, low-dose curcumin stimulated a 10-fold increase in the phagocytic activity of OECs. All of these potently stimulated behavioural characteristics of OECs are favourable for neural repair therapies. Importantly, low-dose curcumin gave a transient activation of p38 kinases, which is in contrast to the high dose curcumin effects on cancer cells in which these MAP kinases tend to undergo prolonged activation. Low-dose curcumin mediated effects on OECs demonstrate cell-type specific stimulation of p38 and ERK kinases. These results constitute the first evidence that low-dose curcumin can modulate the behaviour of olfactory glia into a phenotype potentially more favourable for neural repair and thereby improve the therapeutic use of OECs for neural repair therapies. PMID:25360677

  19. The critical role of macrophage migration inhibitory factor in insulin activity.

    PubMed

    Vujicic, Milica; Senerovic, Lidija; Nikolic, Ivana; Saksida, Tamara; Stosic-Grujicic, Stanislava; Stojanovic, Ivana

    2014-09-01

    Macrophage migration inhibitory factor (MIF) is a molecule with plethora of functions such as regulation of immune response, hormone-like, enzymatic and chaperone-like activity. Further, MIF is a major participant in glucose homeostasis since it is an autocrine stimulator of insulin secretion. MIF absence in male knockout mice (MIF-KO) results in development of glucose intolerance, while sensitivity to insulin is fully preserved. Since our results confirm that beta cells from MIF-KO mice express, produce and secrete insulin similarly to beta cells of their wild type (WT) counterparts C57BL/6 mice, we hypothesize that MIF-KO-derived insulin is less active. Indeed, insulin from MIF-KO islets is unable to significantly induce glucose uptake into hepatocytes and to efficiently promote insulin-triggered Akt phosphorylation determined by immunoblot. However, MIF's tautomerase function is not crucial for insulin biosynthesis since MIF inhibitors had no impact on WT insulin activity. Importantly, MIF recognition by anti-MIF antibody (ELISA) after in vitro co-incubation with purified insulin was significantly lower suggesting that insulin covers MIF immunodominant epitope. In addition, MIF binds insulin within beta cell as confirmed by co-immunoprecipitation. WT and MIF-KO-derived insulin exhibited different cleavage patterns suggesting different protein conformations. Finally, pre-incubation of recombinant MIF with insulin promotes formation of insulin hexamers. These results imply that MIF probably enables proper insulin folding what results in insulin full activity. This newly discovered feature of the cytokine MIF could be potentially important for commercially produced insulin, for increasing its stability and/or bioavailability.

  20. Subsurface mass migration at active volcanoes: what we learnt from the VOLUME project

    NASA Astrophysics Data System (ADS)

    Saccorotti, G.; Volume Team

    2009-04-01

    Movements of multiphase fluids beneath active volcanoes are generally detected at the surface in terms of changes in geophysical and geochemical observables. The prompt detection and interpretation of such signals thus represent a crucial step toward the short-term evaluation of volcanic hazard. Funded through the European 6th framework program, the VOLUME project joined 19 institutions from 6 EU and 5 extra-european countries under the common goal of improving our understanding of how subsurface mass movement manifests itself at the surface, in turn revealing the significance of such movements as precursors to impending eruptions. We integrated high-end experimental procedures with a robust modeling framework to address some of the most relevant issues of modern, quantitative volcanology. In particular, our studies focused on: (i) Unrevealing the complex interplay between hydrothermal and magmatic fluids in generating the observed geophysical / geochemical signals, (ii) Detailing the location, geometry and dynamics of magma pathways and storage zones (iii) Probing variations of the elastic parameters of volcanic media in response to stress changes induced by mass migration, and (iv) Developing a robust computational framework for forward-modelling the geophysical observables resulting from the dynamics of multiphase magmatic systems. VOLUME activities developed at both european and extra-european volcanoes. We present here the most striking results obtained at two italian test-sites, namely Etna and Campi Flegrei, for which we had available data sets of unprecedented sensitivity and temporal resolution. Results from Etna include a) mapping of the shallow plumbing system from Moment-Tensor inversion of broadband seismic signal, b) the detection of deep magma intrusion from inversion of joint gravity-tremor anomalies; c) the measurement of changes in both elastic anisotropy and seismic velocity concomitant to the waning stage of the 2002 NE flank lava effusion; and

  1. Migration of concentrated radionuclide solutions in water-saturated soil investigation of a hypothetical high activity waste solution discharge accident

    SciTech Connect

    Schwarzer, K.; Katscher, W.; Thelen, J.

    1983-01-01

    For the case of postulated leakage from a tank containing a high activity nuclear waste solution, as planned for the German reprocessing plant at Gorleben, the migration of radionuclides in the groundwater current has been examined. As the nuclide migration velocity is strongly influenced by sorption processes, which for a given soil are concentration dependent, adsorption and desorption coefficients for strontium, cesium, ruthenium, and cerium were measured over a wide concentration range in sandy subsoil taken from the Gorleben site. Using the results from the adsorption experiments and neglecting the fact that the sorption coefficients in the case of desorption turn out to be significantly higher, migration velocities and concentration profiles for strontium, cesium, ruthenium, and cerium were calculated with the MOFIS code. The results show significant delay and concentration decrease of the radionuclides with strontium being the ''critical'' element.

  2. Discoidin domain receptor 1 promotes Th17 cell migration by activating the RhoA/ROCK/MAPK/ERK signaling pathway

    PubMed Central

    Azreq, Mohammed-Amine El; Kadiri, Maleck; Boisvert, Marc; Pagé, Nathalie; Tessier, Philippe A.; Aoudjit, Fawzi

    2016-01-01

    Effector T cell migration through the tissue extracellular matrix (ECM) is an important step of the adaptive immune response and in the development of inflammatory diseases. However, the mechanisms involved in this process are still poorly understood. In this study, we addressed the role of a collagen receptor, the discoidin domain receptor 1 (DDR1), in the migration of Th17 cells. We showed that the vast majority of human Th17 cells express DDR1 and that silencing DDR1 or using the blocking recombinant receptor DDR1:Fc significantly reduced their motility and invasion in three-dimensional (3D) collagen. DDR1 promoted Th17 migration by activating RhoA/ROCK and MAPK/ERK signaling pathways. Interestingly, the RhoA/ROCK signaling module was required for MAPK/ERK activation. Finally, we showed that DDR1 is important for the recruitment of Th17 cells into the mouse dorsal air pouch containing the chemoattractant CCL20. Collectively, our results indicate that DDR1, via the activation of RhoA/ROCK/MAPK/ERK signaling axis, is a key pathway of effector T cell migration through collagen of perivascular tissues. As such, DDR1 can contribute to the development of Th17-dependent inflammatory diseases. PMID:27391444

  3. An antagonistic interaction between PlexinB2 and Rnd3 controls RhoA activity and cortical neuron migration

    PubMed Central

    Azzarelli, Roberta; Pacary, Emilie; Garg, Ritu; Garcez, Patricia; van den Berg, Debbie; Riou, Philippe; Ridley, Anne J.; Friedel, Roland H.; Parsons, Maddy; Guillemot, François

    2014-01-01

    A transcriptional programme initiated by the proneural factors Neurog2 and Ascl1 controls successive steps of neurogenesis in the embryonic cerebral cortex. Previous work has shown that proneural factors also confer a migratory behaviour to cortical neurons by inducing the expression of the small GTP-binding proteins such as Rnd2 and Rnd3. However, the directionality of radial migration suggests that migrating neurons also respond to extracellular signal-regulated pathways. Here we show that the Plexin B2 receptor interacts physically and functionally with Rnd3 and stimulates RhoA activity in migrating cortical neurons. Plexin B2 competes with p190RhoGAP for binding to Rnd3, thus blocking the Rnd3-mediated inhibition of RhoA and also recruits RhoGEFs to directly stimulate RhoA activity. Thus, an interaction between the cell-extrinsic Plexin signalling pathway and the cell-intrinsic Ascl1-Rnd3 pathway determines the level of RhoA activity appropriate for cortical neuron migration. PMID:24572910

  4. Tonic activation of GLUK5 kainate receptors decreases neuroblast migration in whole-mounts of the subventricular zone

    PubMed Central

    Platel, Jean-Claude; Heintz, Tristan; Young, Stephanie; Gordon, Valerie; Bordey, Angélique

    2008-01-01

    In the postnatal subventricular zone (SVZ), neuroblasts migrate in chains along the lateral ventricle towards the olfactory bulb. AMPA/kainate receptors as well as metabotropic glutamate receptors subtype 5 (mGluR5) are expressed in SVZ cells. However, the cells expressing these receptors and the function of these receptors remain unexplored. We thus examined whether SVZ neuroblasts express mGluR5 and Ca2+-permeable kainate receptors in mouse slices. Doublecortin (DCX)-immunopositive cells (i.e. neuroblasts) immunostained positive for mGluR5 and GLUK5–7-containing kainate receptors. RT-PCR from ∼10 GFP-fluorescent cell aspirates obtained in acute slices from transgenic mice expressing green fluorescent protein (GFP) under the DCX promoter showed mGluR5 and GLUK5 receptor mRNA in SVZ neuroblasts. Patch-clamp data suggest that ∼60% of neuroblasts express functional GLUK5-containing receptors. Activation of mGluR5 and GLUK5-containing receptors induced Ca2+ increases in 50% and 60% of SVZ neuroblasts, respectively, while most neuroblasts displayed GABAA-mediated Ca2+ responses. To examine the effects of these receptors on the speed of neuroblast migration, we developed a whole-mount preparation of the entire lateral ventricle from postnatal day (P) 20–25 DCX-GFP mice. The GABAA receptor (GABAAR) antagonist bicuculline increased the speed of neuroblast migration by 27%, as previously reported in acute slices. While the mGluR5 antagonist MPEP did not affect the speed of neuroblast migration, the homomeric and heteromeric GLUK5 receptor antagonists, NS3763 and UB302, respectively, increased the migration speed by 38%. These data show that although both GLUK5 receptor and mGluR5 activations increase Ca2+ in neuroblasts, only GLUK5 receptors tonically reduce the speed of neuroblast migration along the lateral ventricle. PMID:18565997

  5. Dihydroartemisinin inhibits vascular endothelial growth factor-induced endothelial cell migration by a p38 mitogen-activated protein kinase-independent pathway.

    PubMed

    Guo, Ling; Dong, Fengyun; Hou, Yinglong; Cai, Weidong; Zhou, Xia; Huang, Ai-Ling; Yang, Min; Allen, Thaddeus D; Liu, Ju

    2014-12-01

    Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, has been demonstrated to possess a strong antiangiogenic activity. However, the molecular mechanisms underlying this effect remain unclear. Endothelial cell (EC) migration is an essential component of angiogenesis, and the p38 mitogen-activated protein kinase (MAPK) signaling pathway plays a key role in the regulation of migration induced by vascular endothelial growth factor (VEGF). The aim of the present study was to investigate the effects of DHA on EC migration and the p38 MAPK signaling pathway. Human umbilical vein ECs (HUVECs) were treated with DHA and VEGF-induced migration was analyzed. The activation of p38 MAPK was detected by western blot analysis, and the migration assays were performed with a p38-specific inhibitor, SB203850. It was revealed that 20 μM DHA significantly reduced EC migration in the transwell migration assay, wound healing assay and electrical cell-substrate impedance sensing real-time analysis. However, DHA did not affect p38 MAPK phosphorylation or expression. In the absence or presence of SB203850, DHA induced a similar proportional reduction of EC migration in the three migration assays. Therefore, the present study demonstrated that DHA inhibits VEGF-induced EC migration via a p38 MAPK-independent pathway.

  6. Thyroxine is a potential endogenous antagonist of macrophage migration inhibitory factor (MIF) activity

    PubMed Central

    Al-Abed, Yousef; Metz, Christine N.; Cheng, Kai Fan; Aljabari, Bayan; VanPatten, Sonya; Blau, Steven; Lee, Hans; Ochani, Mahendar; Pavlov, Valentin A.; Coleman, Thomas; Meurice, Nathalie; Tracey, Kevin J.; Miller, Edmund J.

    2011-01-01

    Abnormally low plasma concentrations of thyroid hormones during sepsis often occur in the absence of thyroidal illness; however, the mechanisms involved in the “euthyroid sick syndrome” remain poorly understood. Here, we describe a previously unrecognized interaction between the thyroid hormone thyroxine (T4) and the proinflammatory cytokine macrophage migration inhibitory factor (MIF), together with its clinical relevance in sepsis. We found that in both patients with severe sepsis, and our rodent model, low plasma T4 concentrations were inversely correlated with plasma MIF concentrations. The MIF molecule contains a hydrophobic pocket that is important for many of its proinflammatory activities. Binding of L-T4 (or its hormonally inert isomer D-T4) significantly, and dose-dependently, inhibited the catalytic activity of this pocket. Moreover, administration of exogenous D-T4 significantly improved survival in mice with severe sepsis. To examine the specificity of the MIF∶T4 interaction, wild-type and MIF knockout mice were subjected to the carrageenan-air pouch model of inflammation and then treated with D-T4 or vehicle. D-T4 significantly inhibited leukocyte infiltration in wild-type mice but not in MIF knockout mice, providing evidence that in vivo T4 may influence MIF-mediated inflammatory responses via inhibition of its hydrophobic proinflammatory pocket. These findings demonstrate a new physiological role for T4 as a natural inhibitor of MIF proinflammatory activity. The data may also, in part, explain the low plasma T4 concentrations in critically ill, euthyroid patients and suggest that targeting the imbalance between MIF and T4 may be beneficial in improving outcome from sepsis. PMID:21536912

  7. Mantle-derived CO2 migration along active faults within an extensional basin margin (Fiumicino, Rome, Italy)

    NASA Astrophysics Data System (ADS)

    Bigi, S.; Beaubien, S. E.; Ciotoli, G.; D'Ambrogi, C.; Doglioni, C.; Ferrante, V.; Lombardi, S.; Milli, S.; Orlando, L.; Ruggiero, L.; Tartarello, M. C.; Sacco, P.

    2014-12-01

    Fluid migration along faults can be highly complex and spatially variable, with the potential for channeled flow, accumulation in capped porous units, fault cross-flow, lateral migration along strike, or complete sealing. Extensional basin margins can be important for such migration, given the associated crustal thinning and decompression that takes place combined with potential geothermal or mantle gas sources. One such example is near the urban area of Rome, situated along the active extensional continental margin of the Tyrrhenian back arc basin and surrounded by Middle-Upper Pleistocene K-rich and arc-related volcanoes. Recent research activities in the area around Fiumicino, a town 25 km to the west of Rome, has highlighted the close spatial link between degassing CO2 and the faults that provide the necessary vertical migration pathways. In particular, detailed soil gas and gas flux surveys have highlighted the release at surface of large volumes of asthenospheric mantle CO2 in correspondence with normal faults observed in a new seismic reflection profile acquired along the Tiber River. Detailed reconstruction of the Pleistocene-Holocene stratigraphy of the area dates fault activity from 20,000 to 9000 years BP. It is proposed that the gas migrates preferentially along the cataclastic tectonic breccias of the faults until it encounters recent, unconsolidated sediments; porous units within this shallow stratigraphy act as temporary secondary traps for the leaking gas, with local gas release at the ground surface occurring where the sealing of the overlying aquitards has been compromised. Degassing and active faults confirm the extensional tectonics affecting the area and the geodynamic scenario of a mantle wedge beneath the western Apennines, associated with ongoing W-directed subduction. Moreover, degassing highlights the potential geochemical and seismic risks for the highly populated urban areas near Rome.

  8. Circulating platelet-neutrophil complexes are important for subsequent neutrophil activation and migration.

    PubMed

    Kornerup, Kristin N; Salmon, Gary P; Pitchford, Simon C; Liu, Wai L; Page, Clive P

    2010-09-01

    Previous studies in our laboratory have shown that platelets are essential for the migration of eosinophils into the lungs of allergic mice, and that this is dependent on the functional expression of platelet P-selectin. We sought to investigate whether the same is true for nonallergic, acute inflammatory stimuli administered to distinct anatomic compartments. Neutrophil trafficking was induced in two models, namely zymosan-induced peritonitis and LPS-induced lung inflammation, and the platelet dependence of these responses investigated utilizing mice rendered thrombocytopenic. The relative contribution of selectins was also investigated. The results presented herein clearly show that platelet depletion (>90%) significantly inhibits neutrophil recruitment in both models. In addition, we show that P-selectin glycoprotein ligand-1, but not P-selectin, is essential for neutrophil recruitment in mice in vivo, thus suggesting the existence of different regulatory mechanisms for the recruitment of leukocyte subsets in response to allergic and nonallergic stimuli. Further studies in human blood demonstrate that low-dose prothrombotic and pro-inflammatory stimuli (CCL17 or CCL22) synergize to induce platelet and neutrophil activation, as well as the formation of platelet-neutrophil conjugates. We conclude that adhesion between platelets and neutrophils in vivo is an important event in acute inflammatory responses. Targeting this interaction may be a successful strategy for inflammatory conditions where current therapy fails to provide adequate treatment.

  9. Activated protein C inhibits neutrophil migration in allergic asthma: a randomised trial.

    PubMed

    de Boer, J Daan; Berger, Marieke; Majoor, Christof J; Kager, Liesbeth M; Meijers, Joost C M; Terpstra, Sanne; Nieuwland, Rienk; Boing, Anita N; Lutter, René; Wouters, Diana; van Mierlo, Gerard J; Zeerleder, Sacha S; Bel, Elisabeth H; van't Veer, Cornelis; de Vos, Alex F; van der Zee, Jaring S; van der Poll, Tom

    2015-12-01

    Asthma patients show evidence of a procoagulant state in their airways, accompanied by an impaired function of the anticoagulant protein C system. We aimed to study the effect of recombinant human activated protein C (rhAPC) in allergic asthma patients.We conducted a randomised, double-blind, placebo-controlled, proof-of-concept study in house dust mite (HDM) allergic asthma patients. Patients were randomised to receive intravenous rhAPC (24 µg·kg(-1)·h(-1); n=12) or placebo (n=12) for 11 h. 4 h after the start of infusion, a first bronchoscopy was performed to challenge one lung segment with saline (control) and a contralateral segment with a combination of HDM extract and lipopolysaccharide (HDM+LPS), thereby mimicking environmental house dust exposure. A second bronchoscopy was conducted 8 h after intrabronchial challenge to obtain bronchoalveolar lavage fluid (BALF).rhAPC did not influence HDM+LPS induced procoagulant changes in the lung. In contrast, rhAPC reduced BALF leukocyte counts by 43% relative to placebo, caused by an inhibitory effect on neutrophil influx (64% reduction), while leaving eosinophil influx unaltered. rhAPC also reduced neutrophil degranulation products in the airways.Intravenous rhAPC attenuates HDM+LPS-induced neutrophil migration and protein release in allergic asthma patients by an effect that does not rely on coagulation inhibition.

  10. Prelamin A Accumulation Attenuates Rac1 Activity and Increases the Intrinsic Migrational Persistence of Aged Vascular Smooth Muscle Cells

    PubMed Central

    Porter, Lauren J.; Holt, Mark R.; Soong, Daniel; Shanahan, Catherine M.; Warren, Derek T.

    2016-01-01

    Vascular smooth muscle cell (VSMC) motility is essential during both physiological and pathological vessel remodeling. Although ageing has emerged as a major risk factor in the development of cardiovascular disease, our understanding of the impact of ageing on VSMC motility remains limited. Prelamin A accumulation is known to drive VSMC ageing and we show that presenescent VSMCs, that have accumulated prelamin A, display increased focal adhesion dynamics, augmented migrational velocity/persistence and attenuated Rac1 activity. Importantly, prelamin A accumulation in proliferative VSMCs, induced by depletion of the prelamin A processing enzyme FACE1, recapitulated the focal adhesion, migrational persistence and Rac1 phenotypes observed in presenescent VSMCs. Moreover, lamin A/C-depleted VSMCs also display reduced Rac1 activity, suggesting that prelamin A influences Rac1 activity by interfering with lamin A/C function at the nuclear envelope. Taken together, these data demonstrate that lamin A/C maintains Rac1 activity in VSMCs and prelamin A disrupts lamin A/C function to reduce Rac1 activity and induce migrational persistence during VSMC ageing. PMID:27854297

  11. Thy-1 Regulates VEGF-Mediated Choroidal Endothelial Cell Activation and Migration: Implications in Neovascular Age-Related Macular Degeneration

    PubMed Central

    Wang, Haibo; Han, Xiaokun; Kunz, Eric; Hartnett, M. Elizabeth

    2016-01-01

    Purpose This study addresses the hypothesis that age-related stresses upregulate Thy-1 in choroidal endothelial cells (CECs) and contribute to CEC activation and migration, processes important in choroidal neovascularization (CNV). Methods Measurements were made of Thy-1 protein (Western blot) in CECs and Thy-1 mRNA (real time quantitative PCR) in CECs treated with VEGF, CCL11, or PBS or in RPE/choroids from young or old donors or lasered or nonlasered mice. Immunolabeled Thy-1 in ocular sections was compared from young versus old human donor eyes or those with or without neovascular AMD or from lasered versus nonlasered mice. Choroidal endothelial cells transfected with Thy-1 or control siRNA or pretreated with Thy-1 blocking peptide or control were stimulated with VEGF or 7-ketocholesterol (7-KC). Choroidal endothelial cell migration, proliferation, cytoskeletal stress fibers, Rac1 activation, and phosphorylated VEGF receptor 2 (VEGFR2), integrin β3, and Src were measured. Statistics were performed using ANOVA. Results Thy-1 was expressed in retinal ganglion cells and in vascular endothelial-cadherin–labeled choroid and localized to human or mouse laser-induced CNV lesions. Thy-1 protein and mRNA were significantly increased in CECs treated with VEGF or CCL11 and in RPE/choroids from aged versus young donor eyes or from lasered mice versus nonlasered controls. Knockdown or inhibition of Thy-1 in CECs significantly reduced VEGF-induced CEC migration and proliferation, stress fiber formation and VEGFR2, Src, integrin β3 and Rac1 activation, and 7-KC–induced Rac1 and Src activation. Conclusions Thy-1 in CECs regulates VEGF-induced CEC activation and migration and links extracellular 7-KC to intracellular signaling. Future studies elucidating Thy-1 mechanisms in neovascular AMD are warranted. PMID:27768790

  12. Cardiac glycoside activities link Na(+)/K(+) ATPase ion-transport to breast cancer cell migration via correlative SAR.

    PubMed

    Magpusao, Anniefer N; Omolloh, George; Johnson, Joshua; Gascón, José; Peczuh, Mark W; Fenteany, Gabriel

    2015-02-20

    The cardiac glycosides ouabain and digitoxin, established Na(+)/K(+) ATPase inhibitors, were found to inhibit MDA-MB-231 breast cancer cell migration through an unbiased chemical genetics screen for cell motility. The Na(+)/K(+) ATPase acts both as an ion-transporter and as a receptor for cardiac glycosides. To delineate which function is related to breast cancer cell migration, structure-activity relationship (SAR) profiles of cardiac glycosides were established at the cellular (cell migration inhibition), molecular (Na(+)/K(+) ATPase inhibition), and atomic (computational docking) levels. The SAR of cardiac glycosides and their analogs revealed a similar profile, a decrease in potency when the parent cardiac glycoside structure was modified, for each activity investigated. Since assays were done at the cellular, molecular, and atomic levels, correlation of SAR profiles across these multiple assays established links between cellular activity and specific protein-small molecule interactions. The observed antimigratory effects in breast cancer cells are directly related to the inhibition of Na(+)/K(+) transport. Specifically, the orientation of cardiac glycosides at the putative cation permeation path formed by transmembrane helices αM1-M6 correlates with the Na(+) pump activity and cell migration. Other Na(+)/K(+) ATPase inhibitors that are structurally distinct from cardiac glycosides also exhibit antimigratory activity, corroborating the conclusion that the antiport function of Na(+)/K(+) ATPase and not the receptor function is important for supporting the motility of MDA-MB-231 breast cancer cells. Correlative SAR can establish new relationships between specific biochemical functions and higher-level cellular processes, particularly for proteins with multiple functions and small molecules with unknown or various modes of action.

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

    PubMed Central

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

    2015-01-01

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

  14. DDR2 plays a role in fibroblast migration independent of adhesion ligand and collagen activated DDR2 tyrosine kinase.

    PubMed

    Herrera-Herrera, Mireya Liliana; Quezada-Calvillo, Roberto

    2012-12-07

    Discoidin domain receptor-2 (DDR2) is a cell surface tyrosine kinase receptor that can be activated by soluble collagen and has been implicated in diverse physiological functions including organism growth and wound repair. In the current studies, we used fibronectin and collagen-coated 2D surfaces and collagen matrices in combination with siRNA technology to investigate the role of DDR2 in a range of fibroblast motile activities. Silencing DDR2 with siRNA inhibited cell spreading and migration, and similar inhibition occurred regardless whether cells were interacting with fibronectin or collagen surfaces. Under the assay conditions used, DDR2 tyrosine kinase activation was not observed unless soluble collagen was added to the incubation medium. Finally silencing DDR2 also inhibited human fibroblast migration in 3D collagen matrices but had no effect on 3D collagen matrix remodeling and contraction. Taken together, our findings suggest that DDR2 is required for normal fibroblast spreading and migration independent of adhesion ligand and collagen activation of DDR2 tyrosine kinase.

  15. α-Solanine inhibits human melanoma cell migration and invasion by reducing matrix metalloproteinase-2/9 activities.

    PubMed

    Lu, Ming-Kun; Shih, Yuan-Wei; Chang Chien, Tzu-Tsung; Fang, Li-Heng; Huang, Hsiang-Ching; Chen, Pin-Shern

    2010-01-01

    α-Solanine, a naturally occurring steroidal glycoalkaloid in potato sprouts, was found to possess anti-carcinogenic properties, such as inhibiting proliferation and inducing apoptosis of tumor cells. However, the effect of α-solanine on cancer metastasis remains unclear. In the present study, we examined the effect of α-solanine on metastasis in vitro. Data demonstrated that α-solanine inhibited proliferation of human melanoma cell line A2058 in a dose-dependent manner. When treated with non-toxic doses of α-solanine, cell migration and invasion were markedly suppressed. Furthermore, α-solanine reduced the activity of matrix metalloproteinase-2 (MMP-2) and MMP-9, which are involved in the migration and invasion of cancer cells. Our biochemical assays indicated that α-solanine potently suppressed the phosphorylation of c-Jun N-terminal kinase (JNK), phosphatidylinositide-3 kinase (PI3K) and Akt, while it did not affect phosphorylation of extracellular signal regulating kinase (ERK). In addition, α-solanine significantly decreased the nuclear level of nuclear factor kappa B (NF-κB), suggesting that α-solanine inhibited NF-κB activity. Taken together, the results suggested that α-solanine inhibited migration and invasion of A2058 cells by reducing MMP-2/9 activities. It also inhibited JNK and PI3K/Akt signaling pathways as well as NF-κB activity. These findings reveal new therapeutic potential for α-solanine in anti-metastatic therapy.

  16. An in vitro larval migration assay for assessing anthelmintic activity of different drug classes against Ascaris suum.

    PubMed

    Zhao, Jianguo; Williams, Andrew R; Hansen, Tina Vicky Alstrup; Thamsborg, Stig M; Cai, Jianping; Song, Shuaibao; Chen, Gang; Kang, Ming; Zhang, Zhuangzhi; Liu, Qun; Han, Qian

    2017-03-18

    In vitro methods have been developed for the detection of anthelmintic resistance in a range of nematode species. However, the life cycle of Ascaris suum renders the commonly used egg hatch assay and larval development assay unusable. In this study we developed a combined multi-well culture and agar gel larval migration assay to test the effect of benzimidazole and tetrahydropyrimidin/imidazothiazole anthelmintics against nine isolates of A. suum collected from locations in China and Denmark. Drugs tested were thiabendazole, fenbendazole, mebendazole, levamisole, and pyrantel. The percentages of larvae that migrated to the surface of each treated and control well were used to calculate the drug concentration which inhibits 50% of the larvae migration (EC50). The values of EC50 of thiabendazole, fenbendazole, mebendazole, levamisole, and pyrantel against A. suum isolates ranged 74-150, 4.9-13.9, 2.3-4.3, 358-1150 and 1100-4000nM, respectively. This combined multi-well culture and agar gel larval migration assay was a sensitive bioassay for anthelmintic activity and could serve as an in vitro method to detect for lowered drug efficacy against A. suum or possibly to screen for anthelmintic drug candidates.

  17. Activation of TRPV2 and BKCa channels by the LL-37 enantiomers stimulates calcium entry and migration of cancer cells

    PubMed Central

    Guéguinou, Maxime; Chourpa, Igor; Fromont, Gaëlle; Bouchet, Ana Maria; Burlaud-Gaillard, Julien; Potier-Cartereau, Marie; Roger, Sébastien; Aucagne, Vincent; Chevalier, Stéphan; Vandier, Christophe

    2016-01-01

    Expression of the antimicrobial peptide hCAP18/LL-37 is associated to malignancy in various cancer forms, stimulating cell migration and metastasis. We report that LL-37 induces migration of three cancer cell lines by activating the TRPV2 calcium-permeable channel and recruiting it to pseudopodia through activation of the PI3K/AKT pathway. Ca2+ entry through TRPV2 cooperated with a K+ efflux through the BKCa channel. In a panel of human breast tumors, the expression of TRPV2 and LL-37 was found to be positively correlated. The D-enantiomer of LL-37 showed identical effects as the L-peptide, suggesting that no binding to a specific receptor was involved. LL-37 attached to caveolae and pseudopodia membranes and decreased membrane fluidity, suggesting that a modification of the physical properties of the lipid membrane bilayer was the underlying mechanism of its effects. PMID:26993604

  18. The hexane extract of Saussurea lappa and its active principle, dehydrocostus lactone, inhibit prostate cancer cell migration.

    PubMed

    Kim, Eun Ji; Hong, Ji Eun; Lim, Soon Sung; Kwon, Gyoo Taik; Kim, Jongdai; Kim, Jong-Sang; Lee, Ki Won; Park, Jung Han Yoon

    2012-01-01

    Saussurea lappa has been used in Chinese traditional medicine for the treatment of abdominal pain, tenesmus, nausea, and cancer; previous studies have shown that S. lappa also induces G(2) growth arrest and apoptosis in gastric cancer cells. In this study, we investigated the effects of hexane extracts of S. lappa (HESLs) on the migration of DU145 and TRAMP-C2 prostate cancer cells. DU145 and TRAMP-C2 cells were cultured in the presence of 0-4 μg/mL HESL with or without 10 ng/mL epidermal growth factor (EGF). HESL inhibited the basal and EGF-induced migration of prostate cancer cells in a dose-dependent manner, whereas HESL did not influence the viability of these cancer cells under the conditions used in this study. Active fractions of HESL were separated via column chromatography, and the structure of the active principle was determined using (1)H and (13)C nuclear magnetic resonance spectroscopy. The active compound, dehydrocostus lactone (DHCL), in fraction 7 dose-dependently inhibited the basal and EGF-induced migration of prostate cancer cells. HESL and DHCL reduced matrix metalloproteinase (MMP)-9 and tissue inhibitor of metalloproteinase (TIMP)-1 secretion but increased TIMP-2 levels in both the absence and presence of EGF. Our results demonstrate that the inhibition of MMP-9 secretion and the stimulation of TIMP-2 secretion contribute to reduced migration of DU145 cells treated with HESL and DHCL. These results indicate that HESL containing its active principle, DHCL, has potential as an antimetastatic agent for the treatment of prostate cancer.

  19. Migrating Activity of the 2010 Madison Plateau, Yellowstone National Park, Earthquake Swarm: Evidence for Fluid Triggering?

    NASA Astrophysics Data System (ADS)

    Shelly, D. R.; Hill, D. P.; Farrell, J.; Massin, F.; Smith, R. B.

    2012-12-01

    activity may have been triggered by the rupture of a confined high-pressure fluid system into neighboring pre-existing crustal fractures. Besides the outward expansion of hypocenters in a manner consistent with diffusional fluid flow, we observe that the swarm activity front is usually led by small earthquakes rather than large ones. The front sometimes propagates outwardly in linear "finger-like" structures consistent with pressure increases along highly permeable linear pathways. Interestingly, nodal planes from double-couple-constrained fault solutions are dominantly strike-slip and are oblique to the general trend of hypocenters. This may suggest en-echelon faulting and/or a component of fault opening, perhaps in a fracture mesh geometry similar to that envisioned by Hill [1977]. The primary dipping structure is likely an inherited Basin and Range normal fault, which could provide a permeable pathway of this orientation. This swarm exhibits many similarities with the 1985 Yellowstone swarm just 5 km to the NW, including its migration patterns and dominant orientation (roughly perpendicular to both the minimum regional compressive stress and the caldera boundary). It is also only ~20 km SE from the closest rupture of the deadly M 7.3 1959 Hebgen Lake normal-faulting earthquake.

  20. Macrophage migration inhibitory factor homolog from Plasmodium yoelii modulates monocyte recruitment and activation in spleen during infection

    PubMed Central

    Zhang, Yanhui; Miura, Kazutoyo; Li, Jian; Tullo, Gregory; Zhu, Feng; Hong, Lingxian; Lin, Tianlong; Su, Xin-zhuan; Long, Carole

    2012-01-01

    Macrophage migration inhibitory factor (MIF) has been shown to be involved in the pathogenesis of severe malaria. Malaria parasites express an MIF homolog that may play a role in regulating host immune responses and a recent study showed that overexpression of MIF reduced parasitemia in a mouse malaria model. Another recent study showed migration of monocytes to the spleen contributed to the control of blood stage infection. However, there are few papers describing the effect of MIF on monocyte recruitment/activation during the infection. We generated recombinant P. yoelii MIF (rPyMIF) and investigated its function on purified mouse CD11b+ cells in vitro and monocyte responses in vivo. The result shows that rPyMIF protein bound to mouse CD11b+ cells and inhibited their random migration in vitro. On the other hand, rPyMIF did not induce cytokine release from the cells directly or modulate LPS-induced cytokine release. Mice immunized with rPyMIF showed transient, but significantly lower parasitemia than the control mice at day 3 after lethal Py17XL challenge. The total number of CD11b+ cells in the spleens was significantly higher in rPyMIF-immunized group. Further investigation revealed that there were significantly higher numbers of recruited and activated monocytes in the spleens of rPyMIF immunization group on day 3. These results indicate that PyMIF potentially modulates monocyte recruitment and activation during infection of P. yoelii erythrocytic stages. PMID:22015474

  1. AhR signaling activation disrupts migration and dendritic growth of olfactory interneurons in the developing mouse

    PubMed Central

    Kimura, Eiki; Ding, Yunjie; Tohyama, Chiharu

    2016-01-01

    Perinatal exposure to a low level of dioxin, a ubiquitous environmental pollutant, has been shown to induce abnormalities in learning and memory, emotion, and sociality in laboratory animals later in adulthood. However, how aryl hydrocarbon receptor (AhR) signaling activation disrupts the higher brain function remains unclear. Therefore, we studied the possible effects of excessive activation of AhR signaling on neurodevelopmental processes, such as cellular migration and neurite growth, in mice. To this end, we transfected a constitutively active-AhR plasmid into stem cells in the lateral ventricle by in vivo electroporation on postnatal day 1. Transfection was found to induce tangential migration delay and morphological abnormalities in neuronal precursors in the rostral migratory stream at 6 days post-electroporation (dpe) as well as disrupt radial migration in the olfactory bulb and apical and basal dendritic growth of the olfactory interneurons in the granule cell layer at 13 and 20 dpe. These results suggest that the retarded development of interneurons by the excessive AhR signaling may at least in part explain the dioxin-induced abnormal behavioral alterations previously reported in laboratory animals. PMID:27197834

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

    PubMed

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

    2012-11-01

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

  3. Role of exchange protein directly activated by cAMP (EPAC1) in breast cancer cell migration and apoptosis.

    PubMed

    Kumar, Naveen; Gupta, Sonal; Dabral, Surbhi; Singh, Shailja; Sehrawat, Seema

    2017-02-16

    Despite the current progress in cancer research and therapy, breast cancer remains the leading cause of mortality among half a million women worldwide. Migration and invasion of cancer cells are associated with prevalent tumor metastasis as well as high mortality. Extensive studies have powerfully established the role of prototypic second messenger cAMP and its two ubiquitously expressed intracellular cAMP receptors namely the classic protein kinaseA/cAMP-dependent protein kinase (PKA) and the more recently discovered exchange protein directly activated by cAMP/cAMP-regulated guanine nucleotide exchange factor (EPAC/cAMP-GEF) in cell migration, cell cycle regulation, and cell death. Herein, we performed the analysis of the Cancer Genome Atlas (TCGA) dataset to evaluate the essential role of cAMP molecular network in breast cancer. We report that EPAC1, PKA, and AKAP9 along with other molecular partners are amplified in breast cancer patients, indicating the importance of this signaling network. To evaluate the functional role of few of these proteins, we used pharmacological modulators and analyzed their effect on cell migration and cell death in breast cancer cells. Hence, we report that inhibition of EPAC1 activity using pharmacological modulators leads to inhibition of cell migration and induces cell death. Additionally, we also observed that the inhibition of EPAC1 resulted in disruption of its association with the microtubule cytoskeleton and delocalization of AKAP9 from the centrosome as analyzed by in vitro imaging. Finally, this study suggests for the first time the mechanistic insights of mode of action of a primary cAMP-dependent sensor, Exchange protein activated by cAMP 1 (EPAC1), via its interaction with A-kinase anchoring protein 9 (AKAP9). This study provides a new cell signaling cAMP-EPAC1-AKAP9 direction to the development of additional biotherapeutics for breast cancer.

  4. Alcohol promotes migration and invasion of triple-negative breast cancer cells through activation of p38 MAPK and JNK.

    PubMed

    Zhao, Ming; Howard, Erin W; Parris, Amanda B; Guo, Zhiying; Zhao, Qingxia; Yang, Xiaohe

    2017-03-01

    Although alcohol is an established breast cancer risk factor, the underlying mechanisms remain unclear. Previous studies examined the general association between alcohol consumption and breast cancer risk; however, the risk for different breast cancer subtypes has been rarely reported. Triple-negative breast cancer (TNBC) is a subtype of breast cancer lacking hormone receptors and HER2 expression, and having poor prognosis. Understanding the molecular mechanisms of TNBC etiology remains a significant challenge. In this study, we investigated cellular responses to alcohol in two TNBC cell lines, MDA-MB-231 and MDA-MB-468. Our results showed that alcohol at low concentrations (0.025-0.1% v/v) induced cell proliferation, migration, and invasion in 1% FBS-containing medium. Molecular analysis indicated that these phenotypic changes were associated with alcohol-induced reactive oxygen species production and increased p38 and JNK phosphorylation. Likewise, p38 or JNK inhibition attenuated alcohol-induced cell migration and invasion. We revealed that alcohol treatment activated/phosphorylated NF-κB regulators and increased transcription of NF-κB-targeted genes. While examining the role of acetaldehyde, the major alcohol metabolite, in alcohol-associated responses in TNBC cells, we saw that acetaldehyde induced cell migration, invasion, and increased phospho-p38, phospho-JNK, and phospho-IκBα in a pattern similar to alcohol treatment. Taken together, we established that alcohol promotes TNBC cell proliferation, migration, and invasion in vitro. The underlying mechanisms involve the induction of oxidative stress and the activation of NF-κB signaling. In particular, the activation of p38 and JNK plays a pivotal role in alcohol-induced cellular responses. These results will advance our understanding of alcohol-mediated development and promotion of TNBC. © 2016 Wiley Periodicals, Inc.

  5. Activity of the pituitary-gonadal axis is increased prior to the onset of spawning migration of chum salmon.

    PubMed

    Onuma, Takeshi A; Sato, Shunpei; Katsumata, Hiroshi; Makino, Keita; Hu, Weiwei; Jodo, Aya; Davis, Nancy D; Dickey, Jon T; Ban, Masatoshi; Ando, Hironori; Fukuwaka, Masa-Aki; Azumaya, Tomonori; Swanson, Penny; Urano, Akihisa

    2009-01-01

    The activity of the pituitary-gonadal axis (PG axis) in pre-migratory and homing chum salmon was examined because endocrine mechanisms underlying the onset of spawning migration remain unknown. Pre-migratory fish were caught in the central Bering Sea in June, July and September 2001, 2002 and 2003, and in the Gulf of Alaska in February 2006. They were classified into immature and maturing adults on the basis of gonadal development. The maturing adults commenced spawning migration to coastal areas by the end of summer, because almost all fish in the Bering Sea were immature in September. In the pituitaries of maturing adults, the copy numbers of FSHbeta mRNA and the FSH content were 2.5- to 100-fold those of the immature fish. Similarly, the amounts of LHbeta mRNA and LH content in the maturing adults were 100- to 1000-fold those of immature fish. The plasma levels of testosterone, 11-ketotestosterone and estradiol were higher than 10 nmol l(-1) in maturing adults, but lower than 1.0 nmol l(-1) in immature fish. The increase in the activity of the PG-axis components had already initiated in the maturing adults while they were still in the Gulf of Alaska in winter. In the homing adults, the pituitary contents and the plasma levels of gonadotropins and plasma sex steroid hormones peaked during upstream migration from the coast to the natal hatchery. The present results thus indicate that the seasonal increase in the activity of the PG axis is an important endocrine event that is inseparable from initiation of spawning migration of chum salmon.

  6. Leader cells regulate collective cell migration via Rac activation in the downstream signaling of integrin β1 and PI3K.

    PubMed

    Yamaguchi, Naoya; Mizutani, Takeomi; Kawabata, Kazushige; Haga, Hisashi

    2015-01-07

    Collective cell migration plays a crucial role in several biological processes, such as embryonic development, wound healing, and cancer metastasis. Here, we focused on collectively migrating Madin-Darby Canine Kidney (MDCK) epithelial cells that follow a leader cell on a collagen gel to clarify the mechanism of collective cell migration. First, we removed a leader cell from the migrating collective with a micromanipulator. This then caused disruption of the cohesive migration of cells that followed in movement, called "follower" cells, which showed the importance of leader cells. Next, we observed localization of active Rac, integrin β1, and PI3K. These molecules were clearly localized in the leading edge of leader cells, but not in follower cells. Live cell imaging using active Rac and active PI3K indicators was performed to elucidate the relationship between Rac, integrin β1, and PI3K. Finally, we demonstrated that the inhibition of these molecules resulted in the disruption of collective migration. Our findings not only demonstrated the significance of a leader cell in collective cell migration, but also showed that Rac, integrin β1, and PI3K are upregulated in leader cells and drive collective cell migration.

  7. WAVE2-Abi2 complex controls growth cone activity and regulates the multipolar-bipolar transition as well as the initiation of glia-guided migration.

    PubMed

    Xie, Min-Jue; Yagi, Hideshi; Kuroda, Kazuki; Wang, Chen-Chi; Komada, Munekazu; Zhao, Hong; Sakakibara, Akira; Miyata, Takaki; Nagata, Koh-Ichi; Oka, Yuichiro; Iguchi, Tokuichi; Sato, Makoto

    2013-06-01

    Glia-guided migration (glia-guided locomotion) during radial migration is a characteristic yet unique mode of migration. In this process, the directionality of migration is predetermined by glial processes and not by growth cones. Prior to the initiation of glia-guided migration, migrating neurons transform from multipolar to bipolar, but the molecular mechanisms underlying this multipolar-bipolar transition and the commencement of glia-guided migration are not fully understood. Here, we demonstrate that the multipolar-bipolar transition is not solely a cell autonomous event; instead, the interaction of growth cones with glial processes plays an essential role. Time-lapse imaging with lattice assays reveals the importance of vigorously active growth cones in searching for appropriate glial scaffolds, completing the transition, and initiating glia-guided migration. These growth cone activities are regulated by Abl kinase and Cdk5 via WAVE2-Abi2 through the phosphorylation of tyrosine 150 and serine 137 of WAVE2. Neurons that do not display such growth cone activities are mispositioned in a more superficial location in the neocortex, suggesting the significance of growth cones for the final location of the neurons. This process occurs in spite of the "inside-out" principle in which later-born neurons are situated more superficially.

  8. Kisspeptin Activates Ankrd 26 Gene Expression in Migrating Embryonic GnRH Neurons.

    PubMed

    Soga, Tomoko; Lim, Wei Ling; Khoo, Alan Soo-Beng; Parhar, Ishwar S

    2016-01-01

    Kisspeptin, a newly discovered neuropeptide, regulates gonadotropin-releasing hormone (GnRH). Kisspeptins are a large RF-amide family of peptides. The kisspeptin coded by KiSS-1 gene is a 145-amino acid protein that is cleaved to C-terminal peptide kisspeptin-10. G-protein-coupled receptor 54 (GPR54) has been identified as a kisspeptin receptor, and it is expressed in GnRH neurons and in a variety of cancer cells. In this study, enhanced green fluorescent protein (EGFP) labeled GnRH cells with migratory properties, which express GPR54, served as a model to study the effects of kisspeptin on cell migration. We monitored EGFP-GnRH neuronal migration in brain slide culture of embryonic day 14 transgenic rat by live cell imaging system and studied the effects of kisspeptin-10 (1 nM) treatment for 36 h on GnRH migration. Furthermore, to determine kisspeptin-induced molecular pathways related with apoptosis and cytoskeletal changes during neuronal migration, we studied the expression levels of candidate genes in laser-captured EGFP-GnRH neurons by real-time PCR. We found that there was no change in the expression level of genes related to cell proliferation and apoptosis. The expression of ankyrin repeat domain-containing protein (ankrd) 26 in EGFP-GnRH neurons was upregulated by the exposure to kisspeptin. These studies suggest that ankrd 26 gene plays an unidentified role in regulating neuronal movement mediated by kisspeptin-GPR54 signaling, which could be a potential pathway to suppress cell migration.

  9. Kisspeptin Activates Ankrd 26 Gene Expression in Migrating Embryonic GnRH Neurons

    PubMed Central

    Soga, Tomoko; Lim, Wei Ling; Khoo, Alan Soo-Beng; Parhar, Ishwar S.

    2016-01-01

    Kisspeptin, a newly discovered neuropeptide, regulates gonadotropin-releasing hormone (GnRH). Kisspeptins are a large RF-amide family of peptides. The kisspeptin coded by KiSS-1 gene is a 145-amino acid protein that is cleaved to C-terminal peptide kisspeptin-10. G-protein-coupled receptor 54 (GPR54) has been identified as a kisspeptin receptor, and it is expressed in GnRH neurons and in a variety of cancer cells. In this study, enhanced green fluorescent protein (EGFP) labeled GnRH cells with migratory properties, which express GPR54, served as a model to study the effects of kisspeptin on cell migration. We monitored EGFP–GnRH neuronal migration in brain slide culture of embryonic day 14 transgenic rat by live cell imaging system and studied the effects of kisspeptin-10 (1 nM) treatment for 36 h on GnRH migration. Furthermore, to determine kisspeptin-induced molecular pathways related with apoptosis and cytoskeletal changes during neuronal migration, we studied the expression levels of candidate genes in laser-captured EGFP–GnRH neurons by real-time PCR. We found that there was no change in the expression level of genes related to cell proliferation and apoptosis. The expression of ankyrin repeat domain-containing protein (ankrd) 26 in EGFP–GnRH neurons was upregulated by the exposure to kisspeptin. These studies suggest that ankrd 26 gene plays an unidentified role in regulating neuronal movement mediated by kisspeptin–GPR54 signaling, which could be a potential pathway to suppress cell migration. PMID:26973595

  10. GPR78 promotes lung cancer cell migration and metastasis by activation of Gαq-Rho GTPase pathway.

    PubMed

    Dong, Dan-Dan; Zhou, Hui; Li, Gao

    2016-11-01

    GPR78 is an orphan G-protein coupled receptor (GPCR) that is predominantly expressed in human brain tissues. Currently, the function of GPR78 is unknown. This study revealed that GPR78 was expressed in lung cancer cells and functioned as a novel regulator of lung cancer cell migration and metastasis. We found that knockdown of GPR78 in lung cancer cells suppressed cell migration. Moreover, GPR78 modulated the formation of actin stress fibers in A549 cells, in a RhoA- and Rac1-dependent manner. At the molecular level, GPR78 regulated cell motility through the activation of Gαq-RhoA/Rac1 pathway. We further demonstrated that in vivo, the knockdown of GPR78 inhibited lung cancer cell metastasis. These findings suggest that GPR78 is a novel regulator for lung cancer metastasis and may serve as a potential drug target against metastatic human lung cancer. [BMB Reports 2016; 49(11): 623-628].

  11. GPR78 promotes lung cancer cell migration and metastasis by activation of Gαq-Rho GTPase pathway

    PubMed Central

    Dong, Dan-Dan; Zhou, Hui; Li, Gao

    2016-01-01

    GPR78 is an orphan G-protein coupled receptor (GPCR) that is predominantly expressed in human brain tissues. Currently, the function of GPR78 is unknown. This study revealed that GPR78 was expressed in lung cancer cells and functioned as a novel regulator of lung cancer cell migration and metastasis. We found that knockdown of GPR78 in lung cancer cells suppressed cell migration. Moreover, GPR78 modulated the formation of actin stress fibers in A549 cells, in a RhoA- and Rac1-dependent manner. At the molecular level, GPR78 regulated cell motility through the activation of Gαq-RhoA/Rac1 pathway. We further demonstrated that in vivo, the knockdown of GPR78 inhibited lung cancer cell metastasis. These findings suggest that GPR78 is a novel regulator for lung cancer metastasis and may serve as a potential drug target against metastatic human lung cancer. PMID:27697106

  12. Variation of Basal EROD Activities in Ten Passerine Bird Species – Relationships with Diet and Migration Status

    PubMed Central

    Rainio, Miia J.; Kanerva, Mirella; Wahlberg, Niklas; Nikinmaa, Mikko; Eeva, Tapio

    2012-01-01

    Inter-specific differences in animal defence mechanisms against toxic substances are currently poorly understood. The ethoxyresorufin-O-deethylase (EROD) enzyme plays an important role in defence against toxic chemicals in a wide variety of animals, and it is an important biomarker for environmental contamination. We compared basal hepatic EROD activity levels among ten passerine species to see if there is inter-specific variation in enzyme activity, especially in relation to their diet and migration status. Migratory insectivores showed higher EROD activity compared to granivores. We hypothesize that the variable invertebrate diet of migratory insectivores contains a wider range of natural toxins than the narrower diet of granivores. This may have affected the evolution of mixed function oxidases (MFO) system and enzyme activities. We further tested whether metabolic rates or relative liver size were associated with the variation in detoxification capacity. We found no association between EROD activity and relative (per mass unit) basal metabolic rate (BMR). Instead, EROD activity and relative liver mass (% of body mass) correlated positively, suggesting that a proportionally large liver also functions efficiently. Our results suggest that granivores and non-migratory birds may be more vulnerable to environmental contaminants than insectivores and migratory birds. The diet and migration status, however, are phylogenetically strongly connected to each other, and their roles cannot be fully separated in our analysis with only ten passerine species. PMID:22479477

  13. Preliminary assessment of the nuclide migration from the activation zone around the proposed Spallation Neutron Source facility

    SciTech Connect

    Dole, L.R.

    1998-09-01

    The purpose of this study is to investigate the potential impacts of migrating radionuclides from the activation zone around the proposed Spallation Neutron Source (SNS). Using conservatively high estimates of the potential inventory of radioactive activation products that could form in the proposed compacted-soil shield berm around an SNS facility on the Oak Ridge Reservation (ORR), a conservative, simplified transport model was used to estimate the potential worst-case concentrations of the 12 long-lived isotopes in the groundwater under a site with the hydrologic characteristics of the ORR.

  14. Exacerbation of experimental autoimmune encephalomyelitis in ceramide synthase 6 knockout mice is associated with enhanced activation/migration of neutrophils.

    PubMed

    Eberle, Max; Ebel, Philipp; Mayer, Christoph A; Barthelmes, Julia; Tafferner, Nadja; Ferreiros, Nerea; Ulshöfer, Thomas; Henke, Marina; Foerch, Christian; de Bazo, Anika Männer; Grösch, Sabine; Geisslinger, Gerd; Willecke, Klaus; Schiffmann, Susanne

    2015-10-01

    Ceramides are mediators of inflammatory processes. In experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we observed that CerS6 mRNA expression was upregulated 15-fold in peripheral blood leukocytes before the onset of EAE symptoms. In peripheral blood leukocytes from MS patients, a 3.9-fold upregulation was found. Total genetic deletion of CerS6 and the selective deletion of CerS6 in peripheral blood leucocytes exacerbated the progression of clinical symptoms in EAE mice. This was associated with enhanced leukocyte, predominantly neutrophil infiltration and enhanced demyelination in the lumbar spinal cord of EAE mice. Interferon-gamma/tumor necrosis factor alpha (IFN-γ/TNF-α) and granulocyte colony-stimulating factor (G-CSF) both drive EAE development and induce expression of the integrin CD11b and the chemokine receptor C-X-C motif chemokine receptor 2 (CXCR2), and we found they also induce CerS6 expression. In vivo, the genetic deletion of CerS6 enhanced the activation/migration of neutrophils, as reflected by an enhanced upregulation of CD11b and CXCR2. In vitro, the genetic deletion of CerS6 enhanced the activation status of IFN-γ/TNF-α-stimulated neutrophils, as shown by increased expression of nitric oxide and CD11b and an increased adhesion capacity. In G-CSF-stimulated neutrophils, the migration status was enhanced, as reflected by an elevated level of CXCR2 and an increased migration capacity. These data suggest that CerS6/C16-Cer mediates feedback regulation by inhibiting the formation of CD11b and CXCR2, which are induced either by IFN-γ/TNF-α or by G-CSF, respectively. We conclude that CerS6/C16-Cer mediates anti-inflammatory effects during the development of EAE and MS possibly by suppressing the migration and deactivation of neutrophils.

  15. Annexin-1 Mediates Microglial Activation and Migration via the CK2 Pathway during Oxygen–Glucose Deprivation/Reperfusion

    PubMed Central

    Liu, Shuangxi; Gao, Yan; Yu, Xiaoli; Zhao, Baoming; Liu, Lu; Zhao, Yin; Luo, Zhenzhao; Shi, Jing

    2016-01-01

    Annexin-1 (ANXA1) has shown neuroprotective effects and microglia play significant roles during central nervous system injury, yet the underlying mechanisms remain unclear. This study sought to determine whether ANXA1 regulates microglial response to oxygen–glucose deprivation/reperfusion (OGD/R) treatment and to clarify the downstream molecular mechanism. In rat hippocampal slices, OGD/R treatment enhanced the ANXA1 expression in neuron, the formyl peptide receptor (FPRs) expression in microglia, and the microglial activation in the CA1 region (cornu ammonis 1). These effects were reversed by the FPRs antagonist Boc1. The cell membrane currents amplitude of BV-2 microglia (the microglial like cell-line) was increased when treated with Ac2-26, the N-terminal peptide of ANXA1. Ac2-26 treatment enhanced BV-2 microglial migration whereas Boc1 treatment inhibited the migration. In BV-2 microglia, both the expression of the CK2 target phosphorylated α-E-catenin and the binding of casein kinase II (CK2) with α-E-catenin were elevated by Ac2-26, these effects were counteracted by the CK2 inhibitor TBB and small interfering (si) RNA directed against transcripts of CK2 and FPRs. Moreover, both TBB and siRNA-mediated inhibition of CK2 blocked Ac2-26-mediated BV-2 microglia migration. Our findings indicate that ANXA1 promotes microglial activation and migration during OGD/R via FPRs, and CK2 target α-E-catenin phosphorylation is involved in this process. PMID:27782092

  16. Hydrogen peroxide stimulates proliferation and migration of human prostate cancer cells through activation of activator protein-1 and up-regulation of the heparin affin regulatory peptide gene.

    PubMed

    Polytarchou, Christos; Hatziapostolou, Maria; Papadimitriou, Evangelia

    2005-12-09

    It is becoming increasingly recognized that hydrogen peroxide (HP) plays a role in cell proliferation and migration. In the present study we found that exogenous HP significantly induced human prostate cancer LNCaP cell proliferation and migration. Heparin affin regulatory peptide (HARP) seems to be involved in the stimulatory effect of HP, because the latter had no effect on stably transfected LNCaP cells that did not express HARP. Moreover, HP significantly increased HARP mRNA and protein amounts in a concentration- and time-dependent manner. Curcumin and activator protein-1 (AP-1) decoy oligonucleotides abrogated both HP-induced HARP expression and LNCaP cell proliferation and migration. HP increased luciferase activity of the 5'-flanking region of the HARP gene introduced in a reporter gene vector, an effect that was abolished when even one of the two putative AP-1 binding sites of the HARP promoter was mutated. The effect of HP seems to be due to the binding of Fra-1, JunD, and phospho-c-Jun to the HARP promoter. These results support the notion that HARP is important for human prostate cancer cell proliferation and migration, establish the role of AP-1 in the up-regulation of HARP expression by low concentrations of HP, and characterize the AP-1 dimers involved.

  17. Hint1 suppresses migration and invasion of hepatocellular carcinoma cells in vitro by modulating girdin activity.

    PubMed

    Wu, Xue-Song; Bao, Tian-Hao; Ke, Yang; Sun, De-Yun; Shi, Zhi-Tian; Tang, Hao-Ran; Wang, Lin

    2016-11-01

    Histidine triad nucleotide-binding protein 1 (Hint1) is a haploinsufficient tumor suppressor gene. Its role in cancer cell migration has not been previously speculated. In the current study, we examined the expression of Hint1 in metastatic and non-metastatic lymph nodes of hepatocellular carcinoma (HCC) patients and further elucidated the effect of Hint1 expression on girdin expression and phosphorylation of AKT and ERK1/2 and on the migration of HCC cells in vitro. Expression of Hint1 and girdin in primary HCC tissues and metastatic and non-metastatic lymph nodes was determined by RT-PCR assays. HepG2 cells were transfected with plasmid vectors overexpressing Hint1 or small interfering RNA (siRNA) targeting Hint1, girdin, Hint1 plus girdin, or the scrambled RNA. Migration and invasion of HCC cells were examined by wound and Transwell assays. Protein expression was detected by immunofluorescence and immunoblotting assays. RT-PCR assays revealed that the messenger RNA (mRNA) transcript levels of Hint1 were markedly lower than those of primary HCC tissues and non-metastatic lymph nodes (P < 0.01). By contrast, the mRNA transcript levels of girdin were significantly higher than non-metastatic lymph nodes (P < 0.05). Furthermore, siRNA knockdown of HINT1 resulted in a significant increase in the mRNA transcript levels of girdin in HepG2 cells (P < 0.05). Wound assays and Transwell assays showed that Hint1 knockdown by siRNA significantly enhanced the migration and invasion of HepG2 cells compared to HepG2 cells transfected with scrambled siRNA. Hint1 knockdown also led to significantly increased phosphorylation of girdin and AKT in HepG2 cells (P < 0.05), which, however, was effectively aborted by girdin knockdown by siRNA (P < 0.05). Hint1 is downregulated in metastatic lymph nodes and is implicated in migration and invasion of HCC cells in vitro by modulating girdin and AKT expression and phosphorylation. The Hint1-girdin-AKT signaling axis should be

  18. Dectin-1 activation induces proliferation and migration of human keratinocytes enhancing wound re-epithelialization.

    PubMed

    van den Berg, Linda M; Zijlstra-Willems, Esther M; Richters, Cornelia D; Ulrich, Magda M W; Geijtenbeek, Teunis B H

    2014-01-01

    Beta-glucans in temporary wound dressings have immuno-stimulatory capacities and have been shown to enhance wound healing in burn patients. Curdlan is a 1,3-linked bacterial/fungal derived beta-glucan that induces inflammatory responses via the C-type lectin receptor dectin-1 on dendritic cells (DCs). Here we investigated the effect of beta-glucan curdlan and the role of dectin-1 expressed by keratinocytes (KCs) in wound healing. Curdlan enhanced migration, proliferation and wound closure of human KCs in a dectin-1 dependent manner, both in vitro and ex vivo. Our data suggest that curdlan induces human KC proliferation and migration and could therefore be used in creams to enhance wound healing.

  19. Arrested α-hydride migration activates a phosphido ligand for C–H insertion

    SciTech Connect

    Hickey, Anne K.; Muñoz, Salvador B.; Lutz, Sean A.; Pink, Maren; Chen, Chun-Hsing; Smith, Jeremy M.

    2016-12-05

    Bulky tris(carbene)borate ligands provide access to high spin iron(II) phosphido complexes. The complex PhB(MesIm)3FeP(H)Ph is thermally unstable, and we observed [PPh] group insertion into a C–H bond of the supporting ligand. An arrested α-hydride migration mechanism suggests increased nucleophilicity of the phosphorus atom facilitates [PPh] group transfer reactivity.

  20. The cAMP-producing agonist beraprost inhibits human vascular smooth muscle cell migration via exchange protein directly activated by cAMP

    PubMed Central

    McKean, Jenny S.; Murray, Fiona; Gibson, George; Shewan, Derryck A.; Tucker, Steven J.; Nixon, Graeme F.

    2015-01-01

    Aims During restenosis, vascular smooth muscle cells (VSMCs) migrate from the vascular media to the developing neointima. Preventing VSMC migration is therefore a therapeutic target for restenosis. Drugs, such as prostacyclin analogues, that increase the intracellular concentration of cyclic adenosine monophosphate (cAMP) can inhibit VSMC migration, but the mechanisms via which this occurs are unknown. Two main downstream mediators of cAMP are protein kinase A (PKA) and exchange protein directly activated by cAMP (Epac). This study has examined the effects of the prostacyclin analogue beraprost on VSMC migration and investigated the intracellular pathways involved. Methods and results In a chemotaxis chamber, human saphenous vein VSMC migrated towards a platelet-derived growth-factor-BB (PDGF) chemogradient. Incubation with therapeutically relevant concentrations of cAMP-producing agonist beraprost significantly decreased PDGF-induced migration. Direct activation of either PKA or Epac inhibited migration whereas inhibition of PKA did not prevent the anti-migratory effect of beraprost. Direct activation of Epac also prevented hyperplasia in ex vivo serum-treated human veins. Using fluorescence resonance energy transfer, we demonstrated that beraprost activated Epac but not PKA. The mechanisms of this Epac-mediated effect involved activation of Rap1 with subsequent inhibition of RhoA. Cytoskeletal rearrangement at the leading edge of the cell was consequently inhibited. Interestingly, Epac1 was localized to the leading edge of migrating VSMC. Conclusions These results indicate that therapeutically relevant concentrations of beraprost can inhibit VSMC migration via a previously unknown mechanism involving the cAMP mediator Epac. This may provide a novel target that could blunt neointimal formation. PMID:26092100

  1. Inhibition of VEGF-Induced VEGFR-2 Activation and HUVEC Migration by Melatonin and Other Bioactive Indolic Compounds

    PubMed Central

    Cerezo, Ana B.; Hornedo-Ortega, Ruth; Álvarez-Fernández, M. Antonia; Troncoso, Ana M.; García-Parrilla, M. Carmen

    2017-01-01

    Excessive concentrations of vascular endothelial growth factor (VEGF) trigger angiogenesis, which causes complications such as the destabilization of atherosclerotic plaques and increased growth of tumors. This work focuses on the determination of the inhibitory activity of melatonin and other indolic related compounds on VEGF-induced VEGF receptor-2 (VEGFR-2) activation and an approximation to the molecular mechanism underlying the inhibition. Quantification of phosphorylated VEGFR-2 was measured by ELISA. Migration wound-healing assay was used to determine cell migration of human umbilical vein endothelial cells (HUVECs). This is the first time that melatonin, 3-indolacetic acid, 5-hydroxytryptophol, and serotonin are proved to significantly inhibit VEGF-induced VEGFR-2 activation in human umbilical vein endothelial cells and subsequent angiogenesis. 3-Indolacetic acid showed the highest inhibitory effect (IC50 value of 0.9704 mM), followed by 5-hydroxytryptophol (35% of inhibition at 0.1 mM), melatonin (30% of inhibition at 1 mM), and serotonin (24% of inhibition at 1 mM). An approximation to the molecular mechanism of the inhibition has been proposed, suggesting that indolic compounds might interact with the cell surface components of the endothelial membrane in a way that prevents VEGF from activating the receptor. Additionally, wound-healing assay revealed that exposure of HUVECs to melatonin and 3-indolacetic acid in the presence of VEGF significantly inhibited cell migration by 87% and 99%, respectively, after 24 h. These data demonstrate that melatonin, 3-indolacetic acid, 5-hydroxytryptophol, and serotonin would be good molecules for future exploitation as anti-VEGF signaling agents. PMID:28282869

  2. Inhibition of VEGF-Induced VEGFR-2 Activation and HUVEC Migration by Melatonin and Other Bioactive Indolic Compounds.

    PubMed

    Cerezo, Ana B; Hornedo-Ortega, Ruth; Álvarez-Fernández, M Antonia; Troncoso, Ana M; García-Parrilla, M Carmen

    2017-03-08

    Excessive concentrations of vascular endothelial growth factor (VEGF) trigger angiogenesis, which causes complications such as the destabilization of atherosclerotic plaques and increased growth of tumors. This work focuses on the determination of the inhibitory activity of melatonin and other indolic related compounds on VEGF-induced VEGF receptor-2 (VEGFR-2) activation and an approximation to the molecular mechanism underlying the inhibition. Quantification of phosphorylated VEGFR-2 was measured by ELISA. Migration wound-healing assay was used to determine cell migration of human umbilical vein endothelial cells (HUVECs). This is the first time that melatonin, 3-indolacetic acid, 5-hydroxytryptophol, and serotonin are proved to significantly inhibit VEGF-induced VEGFR-2 activation in human umbilical vein endothelial cells and subsequent angiogenesis. 3-Indolacetic acid showed the highest inhibitory effect (IC50 value of 0.9704 mM), followed by 5-hydroxytryptophol (35% of inhibition at 0.1 mM), melatonin (30% of inhibition at 1 mM), and serotonin (24% of inhibition at 1 mM). An approximation to the molecular mechanism of the inhibition has been proposed, suggesting that indolic compounds might interact with the cell surface components of the endothelial membrane in a way that prevents VEGF from activating the receptor. Additionally, wound-healing assay revealed that exposure of HUVECs to melatonin and 3-indolacetic acid in the presence of VEGF significantly inhibited cell migration by 87% and 99%, respectively, after 24 h. These data demonstrate that melatonin, 3-indolacetic acid, 5-hydroxytryptophol, and serotonin would be good molecules for future exploitation as anti-VEGF signaling agents.

  3. Cytoarchitecture, Proliferative Activity and Neuroblast Migration in the Subventricular Zone and Lateral Ventricle Extension of the Adult Guinea Pig Brain.

    PubMed

    Jara, Nery; Cifuentes, Manuel; Martínez, Fernando; Salazar, Katterine; Nualart, Francisco

    2016-10-01

    In the mouse brain, neuroblasts generated in the subventricular zone (SVZ) migrate to the olfactory bulb (OB) through the rostral migratory stream (RMS). Although the RMS is not present in the human brain, a migratory pathway that is organized around a ventricular cavity that reaches the OB has been reported. A similar cavity, the lateral ventricle extension (LVE), is found in the adult guinea pig brain. Therefore, we analyzed cytoarchitecture, proliferative activity and precursor cell migration in the SVZ and LVE of 1-, 6- and 12-month-old guinea pigs. In young animals, we used confocal spectral and transmission electron microscopy to identify neuroblasts, astrocytes, and progenitor cells in the SVZ and LVE. Analysis of peroxidase diffusion demonstrated that the LVE was a continuous cavity lined by ependymal cells and surrounded by neuroblasts. Precursor cells were mostly located in the SVZ and migrated from the SVZ to the OB through the LVE. Finally, analysis of 6- and 12-month-old guinea pigs revealed that the LVE was preserved in older animals; however, the number of neurogenic cells was significantly reduced. Consequently, we propose that the guinea pig brain may be used as a new neurogenic model with increased similarity to humans, given that the LVE connects the LV with the OB, as has been described in humans, and that the LVE works a migratory pathway. Stem Cells 2016;34:2574-2586.

  4. Kaempferol-3-O-rutinoside from Afgekia mahidoliae promotes keratinocyte migration through FAK and Rac1 activation.

    PubMed

    Petpiroon, Nareerat; Suktap, Chalermlat; Pongsamart, Sunanta; Chanvorachote, Pithi; Sukrong, Suchada

    2015-07-01

    The restoration of the epidermal epithelium through re-epithelialization is a critical process in wound healing. Directed keratinocyte migration to the wound is required, and the retardation of this process may result in a chronic, non-healing wound. The present study contributes to research aiming to identify promising compounds that promote wound healing using a human keratinocyte model. The effects of three kaempferol glycosides from an Afgekia mahidoliae leaf extract, kaempferol-3-O-arabinoside, kaempferol-3-O-glucoside, and kaempferol-3-O-rutinoside, on keratinocyte migration were determined. Interestingly, kaempferol-3-O-rutinoside exhibited a pronounced effect on wound closure in comparison to the parental kaempferol and other glycosides. The mechanism by which kaempferol-3-O-rutinoside enhances cell migration involves the induction of filopodia and lamellipodia formation, increased cellular levels of phosphorylated FAK (Tyr 397) and phosphorylated Akt (Ser 473), and up-regulation of active Rac1-GTP. The data obtained in this study may support the development of this compound for use in wound healing therapies.

  5. Potent anti-tumour activity of a novel conditionally replicating adenovirus for melanoma via inhibition of migration and invasion

    PubMed Central

    Jiang, G; Yang, C-S; Xu, D; Sun, C; Zheng, J-N; Lei, T-C; Liu, Y-Q

    2014-01-01

    Background: Conditionally replicating adenoviruses (CRAds) represent a novel class of oncological therapeutic agents. One strategy to ensure tumour targeting is to place the essential viral genes under the control of tumour-specific promoters. Ki67 has been selected as a cancer gene therapy target, as it is expressed in most malignant cells but is barely detectable in most normal cells. This study aimed to investigate the effects of a Ki67 promoter-controlled CRAd (Ki67-ZD55-IL-24) on the proliferation and apoptosis of melanoma cells. Methods: Melanoma cells were independently treated with Ki67-ZD55-IL-24, ZD55-IL-24, Ki67-ZD55, and ZD55-EGFP. The cytotoxic potential of each treatment was assessed using cell viability measurements. Cell migration and invasion were assayed using cell migration and invasion assays. Apoptosis was assayed using the annexin V-FITC assay, western blotting, reverse transcriptase PCR (RT–PCR), haematoxylin and eosin (H&E) staining, and the TUNEL assay. Results: Our results showed that Ki67-ZD55-IL-24 had significantly enhanced anti-tumour activity as it more effectively induced apoptosis in melanoma cells than the other agents. Ki67-ZD55-IL-24 also caused the most significant inhibition of cell migration and invasion of melanoma cells. Furthermore, apoptosis was induced more effectively in melanoma xenografts in nude mice. Conclusions: This strategy holds promising potential for the further development of an effective approach to treat malignant melanoma. PMID:24714752

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

    PubMed Central

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

    2015-01-01

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

  7. Tuberin, the tuberous sclerosis complex 2 tumor suppressor gene product, regulates Rho activation, cell adhesion and migration.

    PubMed

    Astrinidis, Aristotelis; Cash, Timothy P; Hunter, Deborah S; Walker, Cheryl L; Chernoff, Jonathan; Henske, Elizabeth P

    2002-12-05

    Tuberous sclerosis complex (TSC) is a tumor suppressor gene syndrome characterized by seizures, mental retardation, autism, and tumors of the brain, kidney, heart, retina, and skin. TSC is caused by mutations in either TSC1 or TSC2, both of which are tumor suppressor genes. Hamartin, the protein product of TSC1, was found to interact with the ezrin-radixin-moesin family of cytoskeletal proteins and to activate the small GTPase Rho. To determine whether tuberin, the TSC2 product, can also activate Rho, we stably expressed full-length human tuberin in two cell types: MDCK cells and ELT3 cells. ELT3 cells lack endogenous tuberin expression. We found that expression of human tuberin in both MDCK and ELT3 cells was associated with an increase in the amount of Rho-GTP, but not in Rac1-GTP or cdc42-GTP. Tuberin expression increased cell adhesion in both cell types, and decreased chemotactic cell migration in ELT3 cells. In MDCK cells, there was a decrease in the amount of total Focal Adhesion Kinase (FAK) and an increase in the fraction of phosphorylated FAK. These findings demonstrate for the first time that tuberin activates Rho and regulates cell adhesion and migration. Pathways involving Rho activation may have relevance to the clinical manifestations of TSC, including pulmonary lymphangioleiomyomatosis.

  8. Smad4 inhibits cell migration via suppression of JNK activity in human pancreatic carcinoma PANC-1 cells

    PubMed Central

    ZHANG, XUEYING; CAO, JUNXIA; PEI, YUJUN; ZHANG, JIYAN; WANG, QINGYANG

    2016-01-01

    Smad4 is a common Smad and is a key downstream regulator of the transforming growth factor-β signaling pathway, in which Smad4 often acts as a potent tumor suppressor and functions in a highly context-dependent manner, particularly in pancreatic cancer. However, little is known regarding whether Smad4 regulates other signaling pathways involved in pancreatic cancer. The present study demonstrated that Smad4 downregulates c-Jun N-terminal kinase (JNK) activity using a Smad4 loss-of-function or gain-of-function analysis. Additionally, stable overexpression of Smad4 clearly affected the migration of human pancreatic epithelioid carcinoma PANC-1 cells, but did not affect cell growth. In addition, the present study revealed that upregulation of mitogen-activated protein kinase phosphatase-1 is required for the reduction of JNK activity by Smad4, leading to a decrease in vascular endothelial growth factor expression and inhibiting cell migration. Overall, the present findings indicate that Smad4 may suppress JNK activation and inhibit the tumor characteristics of pancreatic cancer cells. PMID:27123137

  9. Monocyte migration to arthritis in the rat utilizes both CD11/CD18 and very late activation antigen 4 integrin mechanisms

    PubMed Central

    1995-01-01

    In human and experimental models of arthritis, blood monocytes migrate into the inflamed synovium and joint space. The mechanisms required for monocyte migration across the vascular endothelium in joints is poorly defined. Radiolabeled rat blood monocytes were used to measure monocyte migration to the inflamed joints of rats with adjuvant arthritis, and the role of monocyte adhesion molecules was analyzed. Monocyte accumulation in the inflamed joints was maximal 14-21 d after immunization with adjuvant, when arthritis had fully developed. Blocking mAbs to lymphocyte function-associated antigen 1 (LFA-1), Mac- 1, and very late activation antigen 4 (VLA-4) were used to evaluate the role of these integrins in the migration. Migration to the joints was not inhibited by treatment of the animals with mAb to LFA-1, Mac-1, or VLA-4 alone, and was partially (50%) inhibited in only the most arthritic joint, the talar joint, by the combination of mAb to LFA-1 plus Mac-1. In contrast, this combination inhibited migration to dermal inflammation induced by C5ades Arg, endotoxin, tumor necrosis factor alpha, and polyinosine-cytosine by 60-70%. When mAbs to LFA-1 and VLA-4 were combined, migration to all the inflamed joints was strongly inhibited (80-98%, depending on the joint). Treatment with the combination of the three mAbs to LFA-1, Mac-1, and VLA-4 completely eliminated monocyte migration to all joints and dermal inflammation. The results show that 51Cr blood monocytes can be used to quantify monocyte migration to arthritic joints in the rat. LFA-1 alone or VLA-4 alone is sufficient to mediate most of this migration, and either LFA-1 or VLA-4 is required for monocyte migration to joint inflammation. These results indicate that both the VLA-4 and LFA-1 integrins should be therapeutic targets for suppression of monocyte infiltration of joints in arthritis. PMID:7532681

  10. Migration testing of plastics and microwave-active materials for high-temperature food-use applications.

    PubMed

    Castle, L; Jickells, S M; Gilbert, J; Harrison, N

    1990-01-01

    Temperatures have been measured using a fluoro-optic probe at the food/container or food/packaging interfaces as appropriate, for a range of foods heated in either a microwave or a conventional oven. Reheating ready-prepared foods packaged in plastics pouches, trays or dishes in the microwave oven, according to the manufacturers' instructions, resulted in temperatures in the range 61-121 degrees C. Microwave-active materials (susceptors) in contact with ready-prepared foods frequently reached local spot temperatures above 200 degrees C. For foods cooked in a microwave oven according to published recipes, temperatures from 91 degrees C to 200 degrees C were recorded, whilst similar temperatures (92-194 degrees C) were attained in a conventional oven, but over longer periods of time. These measurements form the basis for examining compliance with specific and overall migration limits for plastics materials. The testing conditions proposed depend on the intended use of the plastic - for microwave oven use for aqueous foods, for all lidding materials, and for reheating of foods, testing would only be required with aqueous simulants for 1 h at 100 degrees C; for unspecified microwave oven use, testing with olive oil would be required for 30 min at 150 degrees C; and for unspecified use in a conventional oven testing with olive oil would be required for 2 h at 175 degrees C. For microwave-active materials, it is proposed that testing is carried out in the microwave oven using a novel semi-solid simulant comprising olive oil and water absorbed onto an inert support of diatomaceous earth. The testing in this instance is carried out with the simulant instead of food in a package and heating in the microwave oven at 600 W for 4 min for every 100 g of simulant employed. There is an option in every case to test for migration using real foods rather than simulants if it can be demonstrated that results using simulants are unrepresentative of those for foods. The proposed

  11. Emodin inhibits migration and invasion of DLD-1 (PRL-3) cells via inhibition of PRL-3 phosphatase activity.

    PubMed

    Han, Young-Min; Lee, Su-Kyung; Jeong, Dae Gwin; Ryu, Seong Eon; Han, Dong Cho; Kim, Dae Keun; Kwon, Byoung-Mog

    2012-01-01

    Anthraquinones have been reported as phosphatase inhibitors. Therefore, anthraquinone derivatives were screened to identify a potent phosphatase inhibitor against the phosphatase of regenerating liver-3 (PRL-3). Emodin strongly inhibited phosphatase activity of PRL-3 with IC(50) values of 3.5μM and blocked PRL-3-induced tumor cell migration and invasion in a dose-dependent manner. Emodin rescued the phosphorylation of ezrin, which is a known PRL-3 substrate. The results of this study reveal that emodin is a PRL-3 inhibitor and a good lead molecule for obtaining a selective PRL-3 inhibitor.

  12. Solamargine inhibits migration and invasion of human hepatocellular carcinoma cells through down-regulation of matrix metalloproteinases 2 and 9 expression and activity.

    PubMed

    Sani, Iman Karimi; Marashi, Seyed Hassan; Kalalinia, Fatemeh

    2015-08-01

    Solamargine is a steroidal alkaloid glycoside isolated from Solanum nigrum. The aim of this study was to investigate the effects of solamargine on tumor migration and invasion in aggressive human hepatocellular carcinoma cells. The MTT assay was used to assess the effects of solamargine on the viability of HepG2 cells. Migration and invasion ability of HepG2 cells under solamargine treatment were examined by a wound healing migration assay and Boyden chamber assay, respectively. Western blotting assays were used to detect the expression of MMP-2 and MMP-9 proteins and MMP-2 and MMP-9 activity were analyzed by gelatin zymography assay. Solamargine reduced HepG2 cell viability in a concentration-dependent manner. At 7.5μM solamargine decreased cell viability by less than 20% in HepG2 cells. A wound healing migration assay and Boyden chamber invasion assay showed that solamargine significantly inhibited in vitro migration and invasion of HepG2 cells. At the highest dose, solamargine decreased cell migration and invasion by more than 70% and 72% in HepG2 cells, respectively. Western blotting and gelatin zymography results showed that solamargine reduced expression and function of MMP-2 and MMP-9 proteins. In conclusion, the results showed that solamargine significantly inhibits migration and invasion of HepG2 cells by down-regulating MMP-2 and MMP-9 expression and activity.

  13. Effect of chloride channel activity on retinal pigment cell proliferation and migration.

    PubMed

    Zhao, Jing; Zhong, Wei; Sun, Lixia; Yin, Yuan; Zheng, Yajuan

    2017-04-01

    The present study aimed to investigate the effects of chloride channels (ClC) on the proliferation and migration of retinal pigment epithelial (RPE) cells, a primary component of proliferative vitreoretinopathy (PVR) membranes. An RPE cell model of phagocytosis was established using fibronectin‑coated latex beads. Cell proliferation was measured by live cell counting. The cell cycle and phagocytosis index was assessed by flow cytometry. Intracellular calcium concentration was quantified using Fura‑2‑acetoxymethyl ester. ClCs were blocked using 5‑nitro‑2‑(3‑phenylpropylamino) benzoic acid (NPPB) and tamoxifen (TAM). NPPB and TAM were identified to inhibit the proliferation of ARPE‑19 human adult RPE cells by arresting them in the G0/G1 phase, inhibit the phagocytosis of fibronectin, and decrease intracellular calcium levels, in a dose‑dependent manner. ClCs serve important roles in mediating human RPE cell proliferation and migration. The underlying mechanisms of action of ClCs are associated with the regulation of calcium. Targeting ClCs may provide a novel strategy to inhibit PVR formation.

  14. FOXP1 enhances tumor cell migration by repression of NFAT1 transcriptional activity in MDA-MB-231 cells.

    PubMed

    Oskay Halacli, Sevil

    2017-01-01

    Until now, forkhead box P1 (FOXP1) has been identified as a tumor suppressor in several correlation studies in breast cancer. Although FOXP1 is defined as a transcriptional repressor that interacts with other transcription factors in various mechanistic studies, there is no study that explains its repressor functions in breast cancer biology. This study demonstrated the repressor function of FOXP1 on nuclear factor of activated T cells (NFAT1) and the migratory effect of this repression in MDA-MB-231 breast cancer cells. Co-immunoprecipitation experiments were performed for the investigation of protein-protein interaction between two transcription factors. Protein-protein interaction on DNA was investigated with EMSA and transcriptional effects of FOXP1 on NFAT1, luciferase reporter assay was performed. Wound healing assay was used to analyze the effects of overexpression of FOXP1 on tumor cell migration. This study showed that FOXP1 has protein-protein interaction with NFAT1 on DNA and enhances breast cancer cell migration by repressing NFAT1 transcriptional activity and FOXP1 shows oncogenic function by regulating breast cancer cell motility.

  15. Neutrophil Migration in the Activation of the Innate Immune Response to Different Flavobacterium psychrophilum Vaccines in Zebrafish (Danio rerio)

    PubMed Central

    Solís, Camila J.; Poblete-Morales, Matías; Cabral, Sergio; Valdés, Juan A.; Reyes, Ariel E.; Avendaño-Herrera, Ruben; Feijóo, Carmen G.

    2015-01-01

    Flavobacterium psychrophilum is a Gram-negative bacterium, responsible for the bacterial cold-water disease and the rainbow trout fry syndrome in freshwater salmonid fish. At present, there is only one commercial vaccine in Chile, made with two Chilean F. psychrophilum isolates and another licensed in Europe. The present study analyzed neutrophil migration, as a marker of innate immune activation, in zebrafish (Danio rerio) in response to different F. psychrophilum bath vaccines, which is the first step in evaluating vaccine effectiveness and efficiency in fish. Results indicated that bacterins of the LM-02-Fp isolate were more immunogenic than those from the LM-13-Fp isolate. However, no differences were observed between the same bacteria inactivated by either formaldehyde or heat. Importantly, the same vaccine formulation without an adjuvant only triggered a mild neutrophil migration compared to the complete vaccine. Observations also found that, after a year of storage at 4°C, the activation of the innate immune system by the different vaccines was considerably decreased. Finally, new vaccine formulations prepared with heat and formaldehyde inactivated LM-02-Fp were significantly more efficient than the available commercial vaccine in regard to stimulating the innate immune system. PMID:25815347

  16. Activated hepatic stellate cells play pivotal roles in hepatocellular carcinoma cell chemoresistance and migration in multicellular tumor spheroids

    PubMed Central

    Song, Yeonhwa; Kim, Se-hyuk; Kim, Kang Mo; Choi, Eun Kyung; Kim, Joon; Seo, Haeng Ran

    2016-01-01

    Most Hepatocellular carcinoma (HCC) are resistant to conventional chemotherapeutic agents and remain an unmet medical need. Recently, multiple studies on the crosstalk between HCC and their tumor microenvironment have been conducted to overcome chemoresistance in HCC. In this study, we formed multicellular tumor spheroids (MCTS) to elucidate the mechanisms of environment-mediated chemoresistance in HCC. We observed that hepatic stellate cells (HSCs) in MCTS significantly increased the compactness of spheroids and exhibited strong resistance to sorafenib and cisplatin relative to other types of stromal cells. Increased collagen 1A1 (COL1A1) expression was apparent in activated HSCs but not in fibroblasts or vascular endothelial cells in MCTS. Additionally, COL1A1 deficiency, which was increased by co-culture with HSCs, decreased the cell-cell interactions and thereby increased the therapeutic efficacy of anticancer therapies in MCTS. Furthermore, losartan, which can inhibit collagen I synthesis, attenuated the compactness of spheroids and increased the therapeutic efficacy of anticancer therapies in MCTS. Meanwhile, activated HSCs facilitated HCC migration by upregulating matrix metallopeptidase 9 (MMP9) in MCTS. Collectively, crosstalk between HCC cells and HSCs promoted HCC chemoresistance and migration by increasing the expression of COL1A1 and MMP9 in MCTS. Hence, targeting HSCs might represent a promising therapeutic strategy for liver cancer therapy. PMID:27853186

  17. Rural-urban migration, urban unemployment and underemployment, and job-search activity in LDCs.

    PubMed

    Fields, G S

    1975-06-01

    A quantity adjustment framework is used to analyze unemployment and underemployment in less developed countries (LDCs). The basic premise of the formal theoretical model presented is that the same kinds of forces that explain the choices of workers between the rural and urban sectors can also explain thier choices between 1 labor market and another within an urban area and are most likely made simultaneously. The decision makers, whether family units or individuals, are presumed to consider the various labor market opportunities available to them and to choose the one which maximizes their expected future income. In the model the primary equilibrating force is taken to be the movement of workers between labor markets, not changes in wages. The point of departure is the received theory of rural urban migration in LDS, which is the model of Harris and Todaro (1970). The 1st step is a summary of the basic features of the model. While accepting their basic approach emphasizing movement of workers rather than changes in wages, it is shown that the particular implication of the model with respect to the equilibrium urban unemployment rate substantially overstates the rates actually observed by Turnham (1971) and others. The analysis is then extended to consider several important factors which have previously been neglected--a more generalized approach to the job search process, the possibility of underemployment in the so-called urban "murky sector," preferential treatment by employers of the better educated, and consideration of labor turnover--and demonstrate that the resulting framework gives predictions closer to actual experience. Harris and Todaro in their original discussion concluded that a combination of a wage subsidy in the modern sector and physical restriction of migration would be required to realize a first best state lying on the economy's production possibility frontier. Subsequently Bhagwati and Srinivasan (1974) challenged them and demonstrated that a

  18. Enhanced Upconversion Luminescence in Yb3+/Tm3+-Codoped Fluoride Active Core/Active Shell/Inert Shell Nanoparticles through Directed Energy Migration

    PubMed Central

    Qiu, Hailong; Yang, Chunhui; Shao, Wei; Damasco, Jossana; Wang, Xianliang; Ågren, Hans; Prasad, Paras N.; Chen, Guanying

    2014-01-01

    The luminescence efficiency of lanthanide-doped upconversion nanoparticles is of particular importance for their embodiment in biophotonic and photonic applications. Here, we show that the upconversion luminescence of typically used NaYF4:Yb3+30%/Tm3+0.5% nanoparticles can be enhanced by ~240 times through a hierarchical active core/active shell/inert shell (NaYF4:Yb3+30%/Tm3+0.5%)/NaYbF4/NaYF4 design, which involves the use of directed energy migration in the second active shell layer. The resulting active core/active shell/inert shell nanoparticles are determined to be about 11 times brighter than that of well-investigated (NaYF4:Yb3+30%/Tm3+0.5%)/NaYF4 active core/inert shell nanoparticles when excited at ~980 nm. The strategy for enhanced upconversion in Yb3+/Tm3+-codoped NaYF4 nanoparticles through directed energy migration might have implications for other types of lanthanide-doped upconversion nanoparticles.

  19. Farnesyl transferase inhibitor FTI-277 inhibits breast cell invasion and migration by blocking H-Ras activation

    PubMed Central

    Lee, Kyung Hun; Koh, Minsoo; Moon, Aree

    2016-01-01

    Hyperactive Ras promotes proliferation and malignant phenotypic conversion of cells in cancer. Ras protein must be associated with cellular membranes for its oncogenic activities through post-translational modifications, including farnesylation. Farnesyltransferase (FTase) is essential for H-Ras membrane targeting, and H-Ras, but not N-Ras, has been demonstrated to cause an invasive phenotype in MCF10A breast epithelial cells. In the present study, it was observed that an FTase inhibitor (FTI), FTI-277, blocked epidermal growth factor (EGF)-induced H-Ras activation, but not N-Ras activation in MDA-MB-231 cells, which express wild-type H-Ras and N-Ras. FTI-277 exerted a more potent inhibitory effect on the proliferation of H-Ras-MCF10A cells and Hs578T breast cancer cells expressing an active mutant of H-Ras than that of MDA-MB-231 cells. The invasive/migratory phenotypes of the H-Ras-MCF10A and Hs578T cells were effectively inhibited by FTI-277 treatment. By contrast, FTI-277 did not affect the invasive/migratory phenotypes of MDA-MB-231 cells. However, the EGF-induced invasion of MDA-MB-231 cells was decreased by FTI-277, implicating that FTI-277 inhibits breast cell invasion and migration by blocking H-Ras activation. Taken together, the results of the present study suggest that FTase inhibition by FTI-277 may be an effective strategy for targeting H-Ras-mediated proliferation, migration and invasion of breast cells. PMID:27602167

  20. Macrophage migration inhibitory factor interacts with HBx and inhibits its apoptotic activity

    SciTech Connect

    Zhang Shimeng; Lin Ruxian; Zhou Zhe; Wen Siyuan; Lin Li; Chen Suhong; Shan Yajun; Cong Yuwen; Wang Shengqi . E-mail: sqwang@nic.bmi.ac.cn

    2006-04-07

    HBx, a transcriptional transactivating protein of hepatitis B virus (HBV), is required for viral infection and has been implicated in virus-mediated liver oncogenesis. However, the precise molecular mechanism remains largely elusive. We used the yeast two-hybrid system to identify that HBx interacts with MIF directly. Macrophage migration inhibitory factor (MIF) is implicated in the regulation of inflammation, cell growth, and even tumor formation. The interaction between HBx and MIF was verified with co-immunoprecipitation, GST pull-down, and cellular colocalization. The expression of MIF was up-regulated in HBV particle producing cell 2.2.15 compared with HepG2 cell. Both HBx and MIF cause HepG2 cell G /G{sub 1} phase arrest, proliferation inhibition, and apoptosis. However, MIF can counteract the apoptotic effect of HBx. These results may provide evidence to explain the link between HBV infection and hepatocellular carcinoma.

  1. Src family kinase activity regulates adhesion, spreading and migration of pancreatic endocrine tumour cells.

    PubMed

    Di Florio, Alessia; Capurso, Gabriele; Milione, Massimo; Panzuto, Francesco; Geremia, Raffaele; Delle Fave, Gianfranco; Sette, Claudio

    2007-03-01

    Pancreatic endocrine tumours (PETs) are rare and 'indolent' neoplasms that usually develop metastatic lesions and exhibit poor response to standard medical treatments. Few studies have investigated pathways responsible for PET cell growth and invasion and no alternative therapeutic strategies have been proposed. In a recent microarray analysis for genes up-regulated in PETs, we have described the up-regulation of soluble Src family tyrosine kinases in this neoplasia, which may represent potentially promising candidates for therapy. Herein, we have investigated the expression and function of Src family kinases in PETS and PET cell lines. Western blot analysis indicated that Src is highly abundant in the PET cell lines CM and QGP-1. Immunohistochemistry and Western blot analyses showed that Src is up-regulated also in human PET lesions. Pharmacological inhibition of Src family kinases by the specific inhibitor PP2 strongly interfered with adhesion, spreading and migration of PET cell lines. Accordingly, the actin cytoskeleton was profoundly altered after inhibition of Src kinases, whereas even prolonged incubation with PP2 exerted no effect on cell cycle progression and/or apoptosis of PET cells. A transient increase in tyrosine phosphorylation of a subset of proteins was observed in QGP-1 cells adhering to the plate, with a peak at 75 min after seeding, when approximately 80% of cells were attached. Inhibition of Src kinases caused a dramatic reduction in the phosphorylation of proteins with different molecular weight that were isolated from the cell extracts by anti-phosphotyrosine immunoprecipitation or pull-down with the SH2 domain of Src. Among them, the docking protein p130Cas interacted with Src and is a major substrate of the Src kinases in QGP-1 cells undergoing adhesion. Our results suggest that Src kinases play a specific role during adhesion, spreading and migration of PET cells and may indicate therapeutical approaches directed to limiting the metastatic

  2. Thymoquinone suppresses migration of LoVo human colon cancer cells by reducing prostaglandin E2 induced COX-2 activation

    PubMed Central

    Hsu, Hsi-Hsien; Chen, Ming-Cheng; Day, Cecilia Hsuan; Lin, Yueh-Min; Li, Shin-Yi; Tu, Chuan-Chou; Padma, Viswanadha Vijaya; Shih, Hui-Nung; Kuo, Wei-Wen; Huang, Chih-Yang

    2017-01-01

    AIM To identify potential anti-cancer constituents in natural extracts that inhibit cancer cell growth and migration. METHODS Our experiments used high dose thymoquinone (TQ) as an inhibitor to arrest LoVo (a human colon adenocarcinoma cell line) cancer cell growth, which was detected by cell proliferation assay and immunoblotting assay. Low dose TQ did not significantly reduce LoVo cancer cell growth. Cyclooxygenase 2 (COX-2) is an enzyme that is involved in the conversion of arachidonic acid into prostaglandin E2 (PGE2) in humans. PGE2 can promote COX-2 protein expression and tumor cell proliferation and was used as a control. RESULTS Our results showed that 20 μmol/L TQ significantly reduced human LoVo colon cancer cell proliferation. TQ treatment reduced the levels of p-PI3K, p-Akt, p-GSK3β, and β-catenin and thereby inhibited the downstream COX-2 expression. Results also showed that the reduction in COX-2 expression resulted in a reduction in PGE2 levels and the suppression of EP2 and EP4 activation. Further analysis showed that TG treatment inhibited the nuclear translocation of β-catenin in LoVo cancer cells. The levels of the cofactors LEF-1 and TCF-4 were also decreased in the nucleus following TQ treatment in a dose-dependent manner. Treatment with low dose TQ inhibited the COX-2 expression at the transcriptional level and the regulation of COX-2 expression efficiently reduced LoVo cell migration. The results were further verified in vivo by confirming the effects of TQ and/or PGE2 using tumor xenografts in nude mice. CONCLUSION TQ inhibits LoVo cancer cell growth and migration, and this result highlights the therapeutic advantage of using TQ in combination therapy against colorectal cancer. PMID:28275297

  3. Pituitary adenylate cyclase-activating polypeptide prevents the effects of ceramides on migration, neurite outgrowth, and cytoskeleton remodeling.

    PubMed

    Falluel-Morel, Anthony; Vaudry, David; Aubert, Nicolas; Galas, Ludovic; Benard, Magalie; Basille, Magali; Fontaine, Marc; Fournier, Alain; Vaudry, Hubert; Gonzalez, Bruno J

    2005-02-15

    During neuronal migration, cells that do not reach their normal destination or fail to establish proper connections are eliminated through an apoptotic process. Recent studies have shown that the proinflammatory cytokine tumor necrosis factor alpha (and its second messengers ceramides) and the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) play a pivotal role in the histogenesis of the cerebellar cortex. However, the effects of ceramides and PACAP on migration of cerebellar granule cells have never been investigated. Time-lapse videomicroscopy recording showed that C2-ceramide, a cell-permeable ceramide analog, and PACAP induced opposite effects on cell motility and neurite outgrowth. C2-ceramide markedly stimulated cell movements during the first hours of treatment and inhibited neuritogenesis, whereas PACAP reduced cell migration and promoted neurite outgrowth. These actions of C2-ceramide on cell motility and neurite outgrowth were accompanied by a disorganization of the actin filament network, depolarization of tubulin, and alteration of the microtubule-associated protein Tau. In contrast, PACAP strengthened the polarization of actin at the emergence cone, increased Tau phosphorylation, and abolished C2-ceramide-evoked alterations of the cytoskeletal architecture. The caspase-inhibitor Z-VAD-FMK, like PACAP, suppressed the "dance of the death" provoked by C2-ceramide. Finally, Z-VAD-FMK and the PP2A inhibitor okadaic acid both prevented the impairment of Tau phosphorylation induced by C2-ceramide. Taken together, these data indicate that the reverse actions of C2-ceramide and PACAP on cerebellar granule cell motility and neurite outgrowth are attributable to their opposite effects on actin distribution, tubulin polymerization, and Tau phosphorylation.

  4. Hypothalamic-pituitary-adrenal axis activity is not elevated in a songbird (Junco hyemalis) preparing for migration.

    PubMed

    Bauer, Carolyn M; Needham, Katie B; Le, Chuong N; Stewart, Emily C; Graham, Jessica L; Ketterson, Ellen D; Greives, Timothy J

    2016-06-01

    During spring, increasing daylengths stimulate gonadal development in migratory birds. However, late-stage reproductive development is typically postponed until migration has been completed. The hypothalamic-pituitary-adrenal (HPA) axis regulates the secretion of glucocorticoids, which have been associated with pre-migratory hyperphagia and fattening. The HPA-axis is also known to suppress the hypothalamic-pituitary-gonadal (HPG) axis, suggesting the possibility that final transition into the breeding life history stage may be slowed by glucocorticoids. We hypothesized that greater HPA-axis activity in individuals preparing for migration may foster preparation for migration while simultaneously acting as a "brake" on the development of the HPG-axis. To test this hypothesis, we sampled baseline corticosterone (CORT), stress-induced CORT, and negative feedback efficacy of Dark-eyed Juncos (Junco hyemalis) in an overwintering population that included both migratory (J.h. hyemalis) and resident (J.h. carolinensis) individuals. We predicted that compared to residents, migrants would have higher baseline CORT, higher stress-induced CORT, and weaker negative feedback. Juncos were sampled in western Virginia in early March, which was about 2-4wk before migratory departure for migrants and 4-5wk before first clutch initiation for residents. Contrary to our predictions, we found that migrants had lower baseline and stress-induced CORT and similar negative feedback efficacy compared with residents, which suggests that delayed breeding in migrants is influenced by other physiological mechanisms. Our findings also suggest that baseline CORT is not elevated during pre-migratory fattening, as migrants had lower baseline CORT and were fatter than residents.

  5. Alpha-fetoprotein activates AKT/mTOR signaling to promote CXCR4 expression and migration of hepatoma cells.

    PubMed

    Zhu, Mingyue; Guo, Junli; Xia, Hua; Li, Wei; Lu, Yan; Dong, Xu; Chen, Yi; Xie, Xieju; Fu, Shigan; Li, Mengsen

    2015-01-01

    CXCR4, stromal cell-derived factor-1α(SDF 1α) receptor, stimulates growth and metastasis of hepatocellular carcinoma (HCC). Alpha-fetoprotein(AFP) governs the expression of some metastasis-related genes. Here we report that AFP and CXCR4 levels correlated in HCC tissues. AFP-expressing vectors induced CXCR4. In agreement, AFP depletion by siRNA decreased CXCR4. AFP co-localized and interacted with PTEN, thus inducing CXCR4 by activating AKT(Ser473) phosphorylation. In turn, phospho-mTOR(Ser2448) entered the nucleus and bound the CXCR4 gene promoter. Thus, AFP promoted migration of HCC cells. In concusion, AFP induced CXCR4 by activating the AKT/mTOR signal pathway.

  6. Alpha-fetoprotein activates AKT/mTOR signaling to promote CXCR4 expression and migration of hepatoma cells

    PubMed Central

    Li, Wei; Lu, Yan; Dong, Xu; Chen, Yi; Xie, Xieju; Fu, Shigan; Li, Mengsen

    2015-01-01

    CXCR4, stromal cell-derived factor-1α(SDF 1α) receptor, stimulates growth and metastasis of hepatocellular carcinoma (HCC). Alpha-fetoprotein(AFP) governs the expression of some metastasis-related genes. Here we report that AFP and CXCR4 levels correlated in HCC tissues. AFP-expressing vectors induced CXCR4. In agreement, AFP depletion by siRNA decreased CXCR4. AFP co-localized and interacted with PTEN, thus inducing CXCR4 by activating AKT(Ser473) phosphorylation. In turn, phospho-mTOR(Ser2448) entered the nucleus and bound the CXCR4 gene promoter. Thus, AFP promoted migration of HCC cells. In concusion, AFP induced CXCR4 by activating the AKT/mTOR signal pathway. PMID:25815363

  7. Multifunctional bioscaffolds for 3D culture of melanoma cells reveal increased MMP activity and migration with BRAF kinase inhibition.

    PubMed

    Leight, Jennifer L; Tokuda, Emi Y; Jones, Caitlin E; Lin, Austin J; Anseth, Kristi S

    2015-04-28

    Matrix metalloproteinases (MMPs) are important for many different types of cancer-related processes, including metastasis. Understanding the functional impact of changes in MMP activity during cancer treatment is an important facet not typically evaluated as part of preclinical research. With MMP activity being a critical component of the metastatic cascade, we designed a 3D hydrogel system to probe whether pharmacological inhibition affected human melanoma cell proteolytic activity; metastatic melanoma is a highly aggressive and drug-resistant form of skin cancer. The relationship between MMP activity and drug treatment is unknown, and therefore we used an in situ fluorogenic MMP sensor peptide to determine how drug treatment affects melanoma cell MMP activity in three dimensions. We encapsulated melanoma cells from varying stages of progression within PEG-based hydrogels to examine the relationship between drug treatment and MMP activity. From these results, a metastatic melanoma cell line (A375) and two inhibitors that inhibit RAF (PLX4032 and sorafenib) were studied further to determine whether changes in MMP activity led to a functional change in cell behavior. A375 cells exhibited increased MMP activity despite an overall decrease in metabolic activity with PLX4032 treatment. The changes in proteolytic activity correlated with increased cell elongation and increased single-cell migration. In contrast, sorafenib did not alter MMP activity or cell motility, showing that the changes induced by PLX4032 were not a universal response to small-molecule inhibition. Therefore, we argue the importance of studying MMP activity with drug treatment and its possible implications for unwanted side effects.

  8. Lamellipodial tension, not integrin/ligand binding, is the crucial factor to realise integrin activation and cell migration.

    PubMed

    Schulte, Carsten; Ferraris, Gian Maria Sarra; Oldani, Amanda; Galluzzi, Massimiliano; Podestà, Alessandro; Puricelli, Luca; de Lorenzi, Valentina; Lenardi, Cristina; Milani, Paolo; Sidenius, Nicolai

    2016-01-01

    The molecular clutch (MC) model proposes that actomyosin-driven force transmission permits integrin-dependent cell migration. To investigate the MC, we introduced diverse talin (TLN) and integrin variants into Flp-In™ T-Rex™ HEK293 cells stably expressing uPAR. Vitronectin variants served as substrate providing uPAR-mediated cell adhesion and optionally integrin binding. This particular system allowed us to selectively analyse key MC proteins and interactions, effectively from the extracellular matrix substrate to intracellular f-actin, and to therewith study mechanobiological aspects of MC engagement also uncoupled from integrin/ligand binding. With this experimental approach, we found that for the initial PIP2-dependent membrane/TLN/f-actin linkage and persistent lamellipodia formation the C-terminal TLN actin binding site (ABS) is dispensable. The establishment of an adequate MC-mediated lamellipodial tension instead depends predominantly on the coupling of this C-terminal TLN ABS to the actomyosin-driven retrograde actin flow force. This lamellipodial tension is crucial for full integrin activation eventually determining integrin-dependent cell migration. In the integrin/ligand-independent condition the frictional membrane resistance participates to these processes. Integrin/ligand binding can also contribute but is not necessarily required.

  9. Endothelial cell activation promotes foam cell formation by monocytes following transendothelial migration in an in vitro model.

    PubMed

    Westhorpe, Clare L V; Dufour, Eric M; Maisa, Anna; Jaworowski, Anthony; Crowe, Suzanne M; Muller, William A

    2012-10-01

    Foam cells are a pathological feature present at all stages of atherosclerosis. Foam cells develop from monocytes that enter the nascent atheroma and subsequently ingest modified low density lipoproteins (LDL). The regulation of this process has previously been studied in vitro using cultured macrophage fed modified LDL. We used our existing in vitro model of transendothelial migration (TEM) to study this process in a more physiologically relevant setting. In our model, monocytes undergo TEM across a primary endothelial monolayer into an underlying three-dimensional collagen matrix in the presence of 20% human serum. Foam cells were detected by Oil Red O staining for intracellular lipid droplets. We demonstrate that sub-endothelial monocytes can develop into foam cells within 48 h of TEM across TNF-α activated endothelium, in the absence of additional lipids. Our data indicate a role for both monocyte-endothelial interactions and soluble factors in the regulation of foam cell development, including oxidation of LDL in situ from lipid present in culture medium following TNF-α stimulation of the endothelial cells. Our study provides a simple model for investigating foam cell development in vitro that mimics cell migration in vivo, and demonstrates the critical role of inflammation in regulating early atherogenic events.

  10. Paracoccidioides brasilinsis-Induced Migration of Dendritic Cells and Subsequent T-Cell Activation in the Lung-Draining Lymph Nodes

    PubMed Central

    Silvana dos Santos, Suelen; Ferreira, Karen Spadari; Almeida, Sandro Rogerio

    2011-01-01

    Paracoccidioidomycosis is a mycotic disease caused by a dimorphic fungus, Paracoccidioides brasiliensis (Pb), that starts with inhalation of the fungus; thus, lung cells such as DC are part of the first line of defense against this microorganism. Migration of DC to the lymph nodes is the first step in initiating T cell responses. The mechanisms involved in resistance to Pb infection are poorly understood, but it is likely that DC play a pivotal role in the induction of effector T cells that control Pb infection. In this study, we showed that after Pb Infection, an important modification of lung DC receptor expression occurred. We observed an increased expression of CCR7 and CD103 on lung DC after infection, as well as MHC-II. After Pb infection, bone marrow-derived DC as well lung DC, migrate to lymph nodes. Migration of lung DC could represent an important mechanism of pathogenesis during PCM infection. In resume our data showed that Pb induced DC migration. Furthermore, we demonstrated that bone marrow-derived DC stimulated by Pb migrate to the lymph nodes and activate a T helper (Th) response. To the best of our knowledge, this is the first reported data showing that Pb induces migration of DC and activate a T helper (Th) response. PMID:21611175

  11. Down-Regulation of ClC-3 Expression Reduces Epidermal Stem Cell Migration by Inhibiting Volume-Activated Chloride Currents.

    PubMed

    Guo, Rui; Pan, Fuqiang; Tian, Yanping; Li, Hongli; Li, Shirong; Cao, Chuan

    2016-06-01

    ClC-3, a member of the ClC chloride (Cl(-)) channel family, has recently been proposed as the primary Cl(-) channel involved in cell volume regulation. Changes in cell volume influence excitability, contraction, migration, pathogen-host interactions, cell proliferation, and cell death processes. In this study, expression and function of ClC-3 channels were investigated during epidermal stem cell (ESC) migration. We observed differential expression of CLC-3 regulates migration of ESCs. Further, whole-cell patch-clamp recordings and image analysis demonstrated ClC-3 expression affected volume-activated Cl(-) current (I Cl,Vol) within ESCs. Live cell imaging systems, designed to observe cellular responses to overexpression and suppression of ClC-3 in real time, indicated ClC-3 may regulate ESC migratory dynamics. We employed IMARIS software to analyze the velocity and distance of ESC migration in vitro to demonstrate the function of ClC-3 channel in ESCs. As our data suggest volume-activated Cl(-) channels play a vital role in migration of ESCs, which contribute to skin repair by migrating from neighboring unwounded epidermis infundibulum, hair follicle or sebaceous glands, ClC-3 may represent a new and valuable target for stem cell therapies.

  12. Progesterone promotes focal adhesion formation and migration in breast cancer cells through induction of protease-activated receptor-1.

    PubMed

    Diaz, Jorge; Aranda, Evelyn; Henriquez, Soledad; Quezada, Marisol; Espinoza, Estefanía; Bravo, Maria Loreto; Oliva, Bárbara; Lange, Soledad; Villalon, Manuel; Jones, Marius; Brosens, Jan J; Kato, Sumie; Cuello, Mauricio A; Knutson, Todd P; Lange, Carol A; Leyton, Lisette; Owen, Gareth I

    2012-08-01

    Progesterone and progestins have been demonstrated to enhance breast cancer cell migration, although the mechanisms are still not fully understood. The protease-activated receptors (PARs) are a family of membrane receptors that are activated by serine proteases in the blood coagulation cascade. PAR1 (F2R) has been reported to be involved in cancer cell migration and overexpressed in breast cancer. We herein demonstrate that PAR1 mRNA and protein are upregulated by progesterone treatment of the breast cancer cell lines ZR-75 and T47D. This regulation is dependent on the progesterone receptor (PR) but does not require PR phosphorylation at serine 294 or the PR proline-rich region mPRO. The increase in PAR1 mRNA was transient, being present at 3  h and returning to basal levels at 18  h. The addition of a PAR1-activating peptide (aPAR1) to cells treated with progesterone resulted in an increase in focal adhesion (FA) formation as measured by the cellular levels of phosphorylated FA kinase. The combined but not individual treatment of progesterone and aPAR1 also markedly increased stress fiber formation and the migratory capacity of breast cancer cells. In agreement with in vitro findings, data mining from the Oncomine platform revealed that PAR1 expression was significantly upregulated in PR-positive breast tumors. Our observation that PAR1 expression and signal transduction are modulated by progesterone provides new insight into how the progestin component in hormone therapies increases the risk of breast cancer in postmenopausal women.

  13. Tracking a defined route for O[subscript 2] migration in a dioxygen-activating diiron enzyme

    SciTech Connect

    Song, Woon Ju; Gucinski, Grant; Sazinsky, Matthew H.; Lippard, Stephen J.

    2011-09-08

    For numerous enzymes reactive toward small gaseous compounds, growing evidence indicates that these substrates diffuse into active site pockets through defined pathways in the protein matrix. Toluene/o-xylene monooxygenase hydroxylase is a dioxygen-activating enzyme. Structural analysis suggests two possible pathways for dioxygen access through the {alpha}-subunit to the diiron center: a channel or a series of hydrophobic cavities. To distinguish which is utilized as the O{sub 2} migration pathway, the dimensions of the cavities and the channel were independently varied by site-directed mutagenesis and confirmed by X-ray crystallography. The rate constants for dioxygen access to the diiron center were derived from the formation rates of a peroxodiiron(III) intermediate, generated upon treatment of the diiron(II) enzyme with O2. This reaction depends on the concentration of dioxygen to the first order. Altering the dimensions of the cavities, but not the channel, changed the rate of dioxygen reactivity with the enzyme. These results strongly suggest that voids comprising the cavities in toluene/o-xylene monooxygenase hydroxylase are not artifacts of protein packing/folding, but rather programmed routes for dioxygen migration through the protein matrix. Because the cavities are not fully connected into the diiron active center in the enzyme resting state, conformational changes will be required to facilitate dioxygen access to the diiron center. We propose that such temporary opening and closing of the cavities may occur in all bacterial multicomponent monooxygenases to control O{sub 2} consumption for efficient catalysis. Our findings suggest that other gas-utilizing enzymes may employ similar structural features to effect substrate passage through a protein matrix.

  14. Mincle activation enhances neutrophil migration and resistance to polymicrobial septic peritonitis

    PubMed Central

    Lee, Wook-Bin; Yan, Ji-Jing; Kang, Ji-Seon; Zhang, Quanri; Choi, Won Young; Kim, Lark Kyun; Kim, Young-Joon

    2017-01-01

    Sepsis is a systemic inflammatory response to bacterial infection. The therapeutic options for treating sepsis are limited. Impaired neutrophil recruitment into the infection site is directly associated with severe sepsis, but the precise mechanism is unclear. Here, we show that Mincle plays a key role in neutrophil migration and resistance during polymicrobial sepsis. Mincle-deficient mice exhibited lower survival rates in experimental sepsis from cecal ligation and puncture and Escherichia coli–induced peritonitis. Mincle deficiency led to higher serum inflammatory cytokine levels and reduced bacterial clearance and neutrophil recruitment. Transcriptome analyses revealed that trehalose dimycolate, a Mincle ligand, reduced the expression of G protein–coupled receptor kinase 2 (GRK2) in neutrophils. Indeed, GRK2 expression was upregulated, but surface expression of the chemokine receptor CXCR2 was downregulated in blood neutrophils from Mincle-deficient mice with septic injury. Moreover, CXCL2-mediated adhesion, chemotactic responses, and F-actin polymerization were reduced in Mincle-deficient neutrophils. Finally, we found that fewer Mincle-deficient neutrophils infiltrated from the blood circulation into the peritoneal fluid in bacterial septic peritonitis compared with wild-type cells. Thus, our results indicate that Mincle plays an important role in neutrophil infiltration and suggest that Mincle signaling may provide a therapeutic target for treating sepsis. PMID:28112221

  15. CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

    NASA Astrophysics Data System (ADS)

    Huang, Fei; Li, Zhen; Yan, Aihua; Zhao, Hui; Liang, Huagen; Gao, Qingyu; Qiang, Yinghuai

    2017-01-01

    Novel semiconductor photocatalysts have been the research focus and received much attention in recent years. The key issues for novel semiconductor photocatalysts are to effectively harvest solar energy and enhance the separation efficiency of the electron-hole pairs. In this work, novel Nb3O7F/CNTs hybrid nanocomposites with enhanced photocatalytic activity have been successfully synthesized by a facile hydrothermal plus etching technique. The important finding is that appropriate pH values lead to the formation of Nb3O7F nanocrystal directly. A general strategy to introdue interaction between Nb3O7F and CNTs markedly enhances the photocatalytic activity of Nb3O7F. Comparatively, Nb3O7F/CNTs nanocomposites exhibit higher photodegradation efficiency and faster photodegradation rate in the solution of methylene blue (MB) under visible-light irradiation. The higher photocatalytic activity may be attributed to more exposed active sites, higher carrier migration and narrower bandgap because of good synergistic effect. The results here may inspire more engineering, new design and facile fabrication of novel photocatalysts with highly photocatalytic activity.

  16. Phosphatidic acid-mediated activation and translocation to the cell surface of sialidase NEU3, promoting signaling for cell migration.

    PubMed

    Shiozaki, Kazuhiro; Takahashi, Kohta; Hosono, Masahiro; Yamaguchi, Kazunori; Hata, Keiko; Shiozaki, Momo; Bassi, Rosaria; Prinetti, Alessandro; Sonnino, Sandro; Nitta, Kazuo; Miyagi, Taeko

    2015-05-01

    The plasma membrane-associated sialidase NEU3 plays crucial roles in regulation of transmembrane signaling, and its aberrant up-regulation in various cancers contributes to malignancy. However, it remains uncertain how NEU3 is naturally activated and locates to plasma membranes, because of its Triton X-100 requirement for the sialidase activity in vitro and its often changing subcellular location. Among phospholipids examined, we demonstrate that phosphatidic acid (PA) elevates its sialidase activity 4 to 5 times at 50 μM in vitro at neutral pH and promotes translocation to the cell surface and cell migration through Ras-signaling in HeLa and COS-1 cells. NEU3 was found to interact selectively with PA as assessed by phospholipid array, liposome coprecipitation, and ELISA assays and to colocalize with phospholipase D (PLD) 1 in response to epidermal growth factor (EGF) or serum stimulation. Studies using tagged NEU3 fragments with point mutations identified PA- and calmodulin (CaM)-binding sites around the N terminus and confirmed its participation in translocation and catalytic activity. EGF induced PLD1 activation concomitantly with enhanced NEU3 translocation to the cell surface, as assessed by confocal microscopy. These results suggest that interactions of NEU3 with PA produced by PLD1 are important for regulation of transmembrane signaling, this aberrant acceleration probably promoting malignancy in cancers.

  17. Phospholipase C-gamma1 potentiates integrin-dependent cell spreading and migration through Pyk2/paxillin activation.

    PubMed

    Choi, Jang Hyun; Yang, Yong-Ryoul; Lee, Seul Ki; Kim, Il-Shin; Ha, Sang Hoon; Kim, Eung-Kyun; Bae, Yun Soo; Ryu, Sung Ho; Suh, Pann-Ghill

    2007-08-01

    Phospholipase C-gamma1 (PLC-gamma1), which generates two second messengers, namely, inositol-1, 4, 5-trisphosphate and diacylglycerol, is implicated in growth factor-mediated chemotaxis. However, the exact role of PLC-gamma1 in integrin-mediated cell adhesion and migration remains poorly understood. In this study, we demonstrate that PLC-gamma1 is required for actin cytoskeletal organization and cell motility through the regulation of Pyk2 and paxillin activation. After fibronectin stimulation, PLC-gamma1 directly interacted with the cytoplasmic tail of integrin beta1. In PLC-gamma1-silenced cells, integrin-induced Pyk2 and paxillin phosphorylation were significantly reduced and PLC-gamma1 potentiated the integrin-induced Pyk2/paxillin activation in its enzymatic activity-dependent manner. In addition, specific knock-down of PLC-gamma1 resulted in a failure to form focal adhesions dependent on fibronectin stimulation, which appeared to be caused by the suppression of Pyk2 and paxillin phosphorylation. Interestingly, PLC-gamma1 potentiated the activations of Rac, thus integrin-induced lamellipodia formation was up-regulated. Consequently, the strength of cell-substratum interaction and cell motility were profoundly up-regulated by PLC-gamma1. Taken together, these results suggest that PLC-gamma1 is a key player in integrin-mediated cell spreading and motility achieved by the activation of Pyk2/paxillin/Rac signaling.

  18. CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

    PubMed Central

    Huang, Fei; Li, Zhen; Yan, Aihua; Zhao, Hui; Liang, Huagen; Gao, Qingyu; Qiang, Yinghuai

    2017-01-01

    Novel semiconductor photocatalysts have been the research focus and received much attention in recent years. The key issues for novel semiconductor photocatalysts are to effectively harvest solar energy and enhance the separation efficiency of the electron-hole pairs. In this work, novel Nb3O7F/CNTs hybrid nanocomposites with enhanced photocatalytic activity have been successfully synthesized by a facile hydrothermal plus etching technique. The important finding is that appropriate pH values lead to the formation of Nb3O7F nanocrystal directly. A general strategy to introdue interaction between Nb3O7F and CNTs markedly enhances the photocatalytic activity of Nb3O7F. Comparatively, Nb3O7F/CNTs nanocomposites exhibit higher photodegradation efficiency and faster photodegradation rate in the solution of methylene blue (MB) under visible-light irradiation. The higher photocatalytic activity may be attributed to more exposed active sites, higher carrier migration and narrower bandgap because of good synergistic effect. The results here may inspire more engineering, new design and facile fabrication of novel photocatalysts with highly photocatalytic activity. PMID:28059123

  19. Epidermal growth factor-like domain 7 promotes migration and invasion of human trophoblast cells through activation of MAPK, PI3K and NOTCH signaling pathways.

    PubMed

    Massimiani, M; Vecchione, L; Piccirilli, D; Spitalieri, P; Amati, F; Salvi, S; Ferrazzani, S; Stuhlmann, H; Campagnolo, L

    2015-05-01

    Epidermal growth factor-like domain 7 (Egfl7) is a gene that encodes a partially secreted protein and whose expression is largely restricted to the endothelia. We recently reported that EGFL7 is also expressed by trophoblast cells in mouse and human placentas. Here, we investigated the molecular pathways that are regulated by EGFL7 in trophoblast cells. Stable EGFL7 overexpression in a Jeg3 human choriocarcinoma cell line resulted in significantly increased cell migration and invasiveness, while cell proliferation was unaffected. Analysis of mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways showed that EGFL7 promotes Jeg3 cell motility by activating both pathways. We show that EGFL7 activates the epidermal growth factor receptor (EGFR) in Jeg3 cells, resulting in downstream activation of extracellular regulated kinases (ERKs). In addition, we provide evidence that EGFL7-triggered migration of Jeg3 cells involves activation of NOTCH signaling. EGFL7 and NOTCH1 are co-expressed in Jeg3 cells, and blocking of NOTCH activation abrogates enhanced migration of Jeg3 cells overexpressing EGFL7. We also demonstrate that signaling through EGFR and NOTCH converged to mediate EGFL7 effects. Reduction of endogenous EGFL7 expression in Jeg3 cells significantly decreased cell migration. We further confirmed that EGFL7 stimulates cell migration by using primary human first trimester trophoblast (PTB) cells overexpressing EGFL7. In conclusion, our data suggest that in trophoblast cells, EGFL7 regulates cell migration and invasion by activating multiple signaling pathways. Our results provide a possible explanation for the correlation between reduced expression of EGFL7 and inadequate trophoblast invasion observed in placentopathies.

  20. Monitoring the onset, propagation, associated bedform migration, and wake of active turbidity currents on the Squamish prodelta slope

    NASA Astrophysics Data System (ADS)

    Hughes Clarke, J. E.; Pratomo, D. G.; Videira Marques, C. R.

    2012-12-01

    . Multibeam water column imagery is used to view the onset, development and decay of turbidity currents in channels on the Squamish prodelta slope. The 2011 program consisted of daily resurveys for a period of 120 days during the freshet period. The initial focus was on resolving bathymetric surface change. Typical morphologic change indicated intermittent upslope migration of in-channel bedforms, sometimes, but not always, associated with an upper slope discrete slide scar. As a serendipitous byproduct, it was found that the deep scattering layer in the fjord was occasionally perturbed by what appeared to be bottom-following intrusive flows. A distally-located, seabed-mounted ADCP confirmed 20 discrete turbidity current events. Surface lowered, optical backscatter profiles indicated that these intrusions were correlated with near-seabed turbidity peaks. In 2012, a week-long program was implemented using hourly resurveys of the channels around the low water spring tide periods. Repetitive underway optical backscatter and CTD profiles were collected extending along the active channels from the delta lip to 1000m offshore. These established the sediment load and relative buoyancy of the surface plume and the fact that the enhanced acoustic volume scattering below represented a descending rain of suspended sediments into the higher density saline lower layers. For several of the events, that descending plume was seen to markedly increase in turbidity close to the seabed, indicating a transition to hyperpycnal conditions. A drop of salinity was also associated with those near seabed high turbidity layers. Those events were followed by the onset of a turbidity current as interpreted from the acoustic volume scattering. The period of upslope bedform migration was restricted to the onset of basal turbidity and first appearance of the flow in the acoustic volume scattering. In the wake of the active flow, an anomalously low acoustic scattering cloud would appear above the

  1. TNF-{alpha} promotes human retinal pigment epithelial (RPE) cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression through activation of Akt/mTORC1 signaling

    SciTech Connect

    Wang, Cheng-hu; Cao, Guo-Fan; Jiang, Qin; Yao, Jin

    2012-08-17

    Highlights: Black-Right-Pointing-Pointer TNF-{alpha} induces MMP-9 expression and secretion to promote RPE cell migration. Black-Right-Pointing-Pointer MAPK activation is not critical for TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer Akt and mTORC1 signaling mediate TNF-{alpha}-induced MMP-9 expression. Black-Right-Pointing-Pointer SIN1 knockdown showed no significant effect on MMP-9 expression by TNF-{alpha}. -- Abstract: Tumor necrosis factor-alpha (TNF-{alpha}) promotes in vitro retinal pigment epithelial (RPE) cell migration to initiate proliferative vitreoretinopathy (PVR). Here we report that TNF-{alpha} promotes human RPE cell migration by inducing matrix metallopeptidase 9 (MMP-9) expression. Inhibition of MMP-9 by its inhibitor or its neutralizing antibody inhibited TNF-{alpha}-induced in vitro RPE cell migration. Reversely, exogenously-added active MMP-9 promoted RPE cell migration. Suppression Akt/mTOR complex 1(mTORC1) activation by LY 294002 and rapamycin inhibited TNF-{alpha}-mediated MMP-9 expression. To introduce a constitutively active Akt (CA-Akt) in cultured RPE cells increased MMP-9 expression, and to block mTORC1 activation by rapamycin inhibited its effect. RNA interference (RNAi)-mediated silencing of SIN1, a key component of mTOR complex 2 (mTORC2), had no effect on MMP-9 expression or secretion. In conclusion, this study suggest that TNF-{alpha} promotes RPE cell migration by inducing MMP-9 expression through activation of Akt/ mTORC1, but not mTORC2 signaling.

  2. Synthesis of coumaperine derivatives: Their NF-κB inhibitory effect, inhibition of cell migration and their cytotoxic activity.

    PubMed

    Nandakumar, Natarajan; Muthuraman, Subramani; Gopinath, Pushparathinam; Nithya, Pattusamy; Gopas, Jacob; Kumar, Rajendran Saravana

    2017-01-05

    Coumaperine (an amide alkaloid, present in white piper) and its derivatives were synthesized and investigated for their cytotoxicity against L428 and A549 cells and their NF-κB inhibitory activity. It was found that the coumaperine derivatives CP-9 and CP-38 suppress NF-κB subunits p50 and p65 in nuclear fractions by western blot and by NF-κB luciferase reporter gene assay in a dose dependent manner. Confirmation of these results was obtained by confocal microscopy. CP-9, CP-32 and CP-38 also exhibited dose dependent cell cytotoxicity in a L428 cells expressing constitutively active NF-κB and in A549 cells, with an IC50 value of 43.25 μg/ml, 0.39 μg/ml and 16.85 μg/ml respectively against L428 cells and 57.15 μg/ml, 69.1 μg/ml and 63.2 μg/ml respectively against A549 cells. In addition, the coumaperine derivatives show remarkable inhibitory activity on the cancer cell migration assay against A549 lung adenocarcinoma cells at the concentrations of 5 μg/ml, 10 μg/ml, and 5 μg/ml of CP-9, CP-32 and CP-38 respectively. Aromatic substituents and number of olefinic double bond in coumaperine derivatives found to influence the inhibitory activity. In luciferase reporter gene assay, di-olefin conjugated coumaperine derivatives, CP-38, CP-32 and PIP exhibited higher inhibitory activity than their corresponding tri-olefin conjugated coumaperine derivatives, CP-102, CP-146 and PIP-155 respectively. CP-32 with a stronger electron donating group (-N(CH3)2) showed better inhibitory activity in luciferase reporter gene assay and in cell proliferation of L428 cells. Simple coumaperine derivative (CP-9, with no substituent) effectively inhibited A549 cells proliferation and migration than the other coumaperine derivatives. CP-9 and CP-38 diminish significantly the NF-κB subunits (p50 and p65) of L428 cells in nuclear fractions at the dosage of 10 μg/ml and 30 μg/ml respectively. Which clearly shows that CP-9 and CP-38 inactivate the NF-κB pathway

  3. Decorin-mediated inhibition of the migration of U87MG glioma cells involves activation of autophagy and suppression of TGF-β signaling.

    PubMed

    Yao, Ting; Zhang, Chen-Guang; Gong, Ming-Tao; Zhang, Min; Wang, Lei; Ding, Wei

    2016-07-01

    Decorin (DCN) is a major member of the small leucine-rich proteoglycan (SLRP) family that is critically involved in tumorigenesis and the development of metastasis of cancers, including glioma. Overexpression of DCN was indicated to suppress glioma cell growth. However, the role of DCN in the migration of glioma cells remain elusive. In this study, we found that treatment with exogenous DCN inhibited the adhesion and migration of U87MG glioma cells with down-regulation of TGF-β signaling. DCN also activated autophagy, as indicated by monodansylcadaverine (MDC) staining, increase in LC3 I/LC3 II conversion, and p62/SQSTM1 degradation in U87MG cells. The increased activity of autophagy was found to be connected to the inhibition on glioma cell migration. Knockdown of DCN expression or the disruption of autophagy with 3-methyladenine (3-MA) was able to reduce the suppression on cell adhesion and migration induced by DCN. When U87MG cells were treated with temozolomide (TMZ), induction of autophagy and up-regulation of DCN were observed, accompanied by suppressed cell adhesion and migration. Transfection of siRNA targeting DCN attenuated the suppressive effect of TMZ on glioma cell migration and adhesion. Our results indicated that the migration of glioma cells was under the control of the active status of autophagy, with DCN serving as a key player, as well as an indicator of the outcome. Therefore, it is suggested that autophagy-modulating reagents could be considered for the treatment of invasive glioma.

  4. Benzo(a)pyrene inhibits migration and invasion of extravillous trophoblast HTR-8/SVneo cells via activation of the ERK and JNK pathway.

    PubMed

    Liu, Liyuan; Wang, Yingxiong; Shen, Cha; He, Junlin; Liu, Xueqing; Ding, Yubin; Gao, Rufei; Chen, Xuemei

    2016-07-01

    Benzo(a)pyrene (BaP) is a persistent organic pollutant (POP) that is a serious threat to human health. Numerous studies have shown that BaP causes adverse effects in pregnancy, but the mechanism remains unclear. The moderate invasion of trophoblast cells into the endometrium is an important factor during successful embryo implantation. The aim of this study was to investigate the effect and mechanism of BaP on the invasion and migration of trophoblast cells. HTR-8/SVneo cells were treated with different concentrations (1, 5, 10, 25, 50 and 100 μM) of BaP. The invasion and migration of HTR-8/SVneo cells were observed after BaP treatment. The protein levels related to migration and invasion was detected by Western blot. The results confirmed that BaP inhibits the migration and invasion of extravillous trophoblast HTR-8/SVneo cells. Further investigations indicated that the protein levels of MMP-2, MMP-9 and E-cadherin in HTR-8/SVneo cells were changed by BaP treatment. Moreover, the data demonstrated that BaP activated the MAPK signaling pathway. Pretreatment with specific inhibitors of MAPK rescued BaP-induced change in the migration and invasion of HTR-8/SVneo cells. Taken together, our results indicated that BaP inhibits invasion and the migration of HTR-8/SVneo cells, which might cause a failure in early pregnancy. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Apamin inhibits PDGF-BB-induced vascular smooth muscle cell proliferation and migration through suppressions of activated Akt and Erk signaling pathway.

    PubMed

    Kim, Jung-Yeon; Kim, Kyung-Hyun; Lee, Woo-Ram; An, Hyun-Jin; Lee, Sun-Jae; Han, Sang-Mi; Lee, Kwang-Gill; Park, Yoon-Yub; Kim, Kee-Sik; Lee, Young-Soo; Park, Kwan-Kyu

    2015-07-01

    The increased proliferation and migration of vascular smooth muscle cells (VSMC) are key process in the development of atherosclerosis lesions. Platelet-derived growth factor (PDGF) initiates a multitude of biological effects that contribute to VSMC proliferation and migration. Apamin, a component of bee venom, has been known to block the Ca(2+)-activated K(+) channels. However, the effects of apamin in the regulation PDGF-BB-induced VSMC proliferation and migration has not been identified. In this study, we investigate the inhibitory effect of apamin on PDGF-BB-induced VSMC proliferation and migration. Apamin suppressed the PDGF-BB-induced VSMC proliferation and migration with no apparent cytotoxic effect. In accordance with these findings, apamin induced the arrest of cell cycle progression at G0/G1 phase. Apamin also decreased the expressions of G0/G1 specific regulatory proteins including proliferating cell nuclear antigen (PCNA), cyclin D1, cyclin-dependent kinases (CDK) 4, cyclin E and CDK2, as well as increased the expression of p21(Cip1) in PDGF-BB-induced VSMC. Moreover, apamin inhibited PDGF-BB-induced phosphorylation of Akt and Erk1/2. These results suggest that apamin plays an important role in prevention of vascular proliferation and migration through the G0/G1 cell cycle arrest by PDGF signaling pathway. Thus, apamin may be a promising candidate for the therapy of atherosclerosis.

  6. Intermediate-conductance calcium-activated potassium channel KCa3.1 and chloride channel modulate chemokine ligand (CCL19/CCL21)-induced migration of dendritic cells.

    PubMed

    Shao, Zhifei; Gaurav, Rohit; Agrawal, Devendra K

    2015-07-01

    The role of ion channels is largely unknown in chemokine-induced migration in nonexcitable cells such as dendritic cells (DCs). Here, we examined the role of intermediate-conductance calcium-activated potassium channel (KCa3.1) and chloride channel (CLC3) in lymphatic chemokine-induced migration of DCs. The amplitude and kinetics of chemokine ligand (CCL19/CCL21)-induced Ca(2+) influx were associated with chemokine receptor 7 expression levels, extracellular-free Ca(2+) and Cl(-), and independent of extracellular K(+). Chemokines (CCL19 and CCL21) and KCa3.1 activator (1-ethyl-1,3-dihydro-2H-benzimidazol-2-one) induced plasma membrane hyperpolarization and K(+) efflux, which was blocked by 1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole, suggesting that KCa3.1 carried larger conductance than the inward calcium release-activated calcium channel. Blockade of KCa3.1, low Cl(-) in the medium, and low dose of 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) impaired CCL19/CCL21-induced Ca(2+) influx, cell volume change, and DC migration. High doses of DIDS completely blocked DC migration possibly by significantly disrupting mitochondrial membrane potential. In conclusion, KCa3.1 and CLC3 are critical in human DC migration by synergistically regulating membrane potential, chemokine-induced Ca(2+) influx, and cell volume.

  7. Displacement correlations between a single mesenchymal-like cell and its nucleus effectively link subcellular activities and motility in cell migration analysis

    PubMed Central

    Lan, Tian; Cheng, Kai; Ren, Tina; Arce, Stephen Hugo; Tseng, Yiider

    2016-01-01

    Cell migration is an essential process in organism development and physiological maintenance. Although current methods permit accurate comparisons of the effects of molecular manipulations and drug applications on cell motility, effects of alterations in subcellular activities on motility cannot be fully elucidated from those methods. Here, we develop a strategy termed cell-nuclear (CN) correlation to parameterize represented dynamic subcellular activities and to quantify their contributions in mesenchymal-like migration. Based on the biophysical meaning of the CN correlation, we propose a cell migration potential index (CMPI) to measure cell motility. When the effectiveness of CMPI was evaluated with respect to one of the most popular cell migration analysis methods, Persistent Random Walk, we found that the cell motility estimates among six cell lines used in this study were highly consistent between these two approaches. Further evaluations indicated that CMPI can be determined using a shorter time period and smaller cell sample size, and it possesses excellent reliability and applicability, even in the presence of a wide range of noise, as might be generated from individual imaging acquisition systems. The novel approach outlined here introduces a robust strategy through an analysis of subcellular locomotion activities for single cell migration assessment. PMID:27670131

  8. Displacement correlations between a single mesenchymal-like cell and its nucleus effectively link subcellular activities and motility in cell migration analysis

    NASA Astrophysics Data System (ADS)

    Lan, Tian; Cheng, Kai; Ren, Tina; Arce, Stephen Hugo; Tseng, Yiider

    2016-09-01

    Cell migration is an essential process in organism development and physiological maintenance. Although current methods permit accurate comparisons of the effects of molecular manipulations and drug applications on cell motility, effects of alterations in subcellular activities on motility cannot be fully elucidated from those methods. Here, we develop a strategy termed cell-nuclear (CN) correlation to parameterize represented dynamic subcellular activities and to quantify their contributions in mesenchymal-like migration. Based on the biophysical meaning of the CN correlation, we propose a cell migration potential index (CMPI) to measure cell motility. When the effectiveness of CMPI was evaluated with respect to one of the most popular cell migration analysis methods, Persistent Random Walk, we found that the cell motility estimates among six cell lines used in this study were highly consistent between these two approaches. Further evaluations indicated that CMPI can be determined using a shorter time period and smaller cell sample size, and it possesses excellent reliability and applicability, even in the presence of a wide range of noise, as might be generated from individual imaging acquisition systems. The novel approach outlined here introduces a robust strategy through an analysis of subcellular locomotion activities for single cell migration assessment.

  9. Cell Migration

    PubMed Central

    Trepat, Xavier; Chen, Zaozao; Jacobson, Ken

    2015-01-01

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

  10. Transcription factor activity of estrogen receptor α activation upon nonylphenol or bisphenol A treatment enhances the in vitro proliferation, invasion, and migration of neuroblastoma cells

    PubMed Central

    Ma, Hongda; Yao, Yao; Wang, Changli; Zhang, Liyu; Cheng, Long; Wang, Yiren; Wang, Tao; Liang, Erguang; Jia, Hui; Ye, Qinong; Hou, Mingxiao; Feng, Fan

    2016-01-01

    Many kinds of endocrine-disrupting chemicals (EDCs), for example, the environmental estrogens bisphenol A and nonylphenol, may regulate the activity of estrogen receptor α (ERα) and therefore induce potential disruption of normal endocrine function. However, the involvement of EDCs in human cancers, especially in endocrine-related cancer neuroblastoma regulation, is not very clear. In this work, results showed that upon bisphenol A or nonylphenol treatment, the transcription factor activity of ERα was significantly increased in neuroblastoma cell line SH-SY5Y. Bisphenol A and nonylphenol could enhance ERα activity via recruiting it to the target gene promoter. Furthermore, treatment of bisphenol A and nonylphenol enhanced the in vitro proliferation, invasion, and migration ability of neuroblastoma cells. By investigating the role of EDC-induced ERα upregulation, our data extend the understanding of the function of EDCs and further suggest that ERα might be a potential therapeutic target in human neuroblastoma treatment. PMID:27366082

  11. Phase inversion of neural activity in the olfactory and visual systems of a night-migratory bird during migration.

    PubMed

    Rastogi, Ashutosh; Kumari, Yatinesh; Rani, Sangeeta; Kumar, Vinod

    2011-07-01

    Olfactory and visual sensory mechanisms seem to play a critical role in migratory orientation and navigation. How these two mechanisms are functionally linked with other migratory processes is unknown. We investigated this, in relation to the profound behavioural shift that occurs during migration in the night-migratory blackheaded bunting (Emberiza melanocephala). Photosensitive unstimulated birds singly housed in activity cages were subjected to long days (LD 16/8). The activity of each bird was continuously monitored. Daily activity pattern defined the nonmigratory phase (no nocturnal activity) and migratory phase (intense nocturnal activity, Zugunruhe). Body mass and testis size were measured at the beginning and end of the experiment. Long days induced the migratory phenotype (body fattening and Zugunruhe) and testis maturation. The c-fos (Fos) immunoreactivity, as marker of the neural activity of the olfactory and visual subsystems, was measured at midday (8 h after lights-on) and midnight (4 h after lights-off) after the first seven long days (nonmigratory phase) and after seven nights of the Zugunruhe (migratory phase). In the nonmigratory phase, Fos-like immunoreactive (Fos-lir) cells in the olfactory and visual subsystems were high in the day and low at night. In the migratory phase, this was reversed; Fos-lir cells were high at night and low in the day. The phase inversion of neural activity in the olfactory and visual systems in parallel with the behavioral shift suggests a functional coupling between the systems governing migratory flight (expressed as Zugunruhe) and migratory orientation and navigation.

  12. Detoxification enzyme activities (CYP1A1 and GST) in the skin of humpback whales as a function of organochlorine burdens and migration status.

    PubMed

    Bengtson Nash, S; Dawson, A; Burkhard, M; Waugh, C; Huston, W

    2014-10-01

    The activities of glutathione-s-transferase (GST) and cytochrome P-450 1A1 (CYP1A1) enzymes were measured in freshly extracted epidermis of live-biopsied, migrating, southern hemisphere humpback whales (Megaptera novaeangliae). The two quantified enzyme activities did not correlate strongly with each other. Similarly, neither correlated strongly with any of the organochlorine compound groups previously measured in the superficial blubber of the sample biopsy core, likely reflecting the anticipated low levels of typical aryl-hydrocarbon receptor ligands. GST activity did not differ significantly between genders or between northward (early migration) or southward (late migration) migrating cohorts. Indeed, the inter-individual variability in GST measurements was relatively low. This observation raises the possibility that measured activities were basal activities and that GST function was inherently impacted by the fasting state of the sampled animals, as seen in other species. These results do not support the implementation of CYP1A1 or GST as effective biomarkers of organochlorine contaminant burdens in southern hemisphere populations of humpback whales as advocated for other cetacean species. Further investigation of GST activity in feeding versus fasting cohorts may, however, provide some insight into the fasting metabolism of these behaviourally adapted populations.

  13. Modulation of tumor cell stiffness and migration by type IV collagen through direct activation of integrin signaling pathway.

    PubMed

    Chen, Sheng-Yi; Lin, Jo-Shi; Yang, Bei-Chang

    2014-08-01

    Excessive collagen deposition plays a critical role in tumor progression and metastasis. To understand how type IV collagen affects mechanical stiffness and migration, low-collagen-IV-expressing transfectants of B16F10, U118MG, and Huh7 (denoted shCol cells) were established by the lentiviral-mediated delivery of small interfering RNA against type IV-α1 collagen (Col4A1). Although having similar growth rates, shCol cells showed a flatter morphology compared to that of the corresponding controls. Notably, knocking down the Col4A1 gene conferred the cells with higher levels of elasticity and lower motility. Exposure to blocking antibodies against human β1 integrin or α2β1 integrin or the pharmacological inhibition of Src and ERK activity by PP1 and U0126, respectively, effectively reduced cell motility and raised cell stiffness. Reduced Src and ERK activities in shCol cells indicate the involvement of a collagen IV/integrin signaling pathway. The forced expression of β1 integrin significantly stimulated Src and ERK phosphorylation, reduced cell stiffness, and accelerated cell motility. In an experimental metastasis assay using C57BL/6 mice, B16F10 shCol cells formed significantly fewer and smaller lung nodules, confirming the contribution of collagen to metastasis. In summary, the integrin signaling pathway activated in a tumor environment with collagen deposition is responsible for low cell elasticity and high metastatic ability.

  14. Preliminary Assessment of the Nuclide Migration from the Activation Zone Around the Proposed Spallation Neutron Source Facility

    SciTech Connect

    Dole, L.R.

    1998-09-01

    The purpose of this study is to investigate the potential impacts of migrating radionuclides from the activation zone around the proposed Spallation Neutron Source (SNS). Using conservatively high estimates of the potential inventory of radioactive activation products that could form in the proposed compacted-soil shield berm around an SNS facility on the Oak Ridge Reservation (ORR), a conservative, simplified transport model was used to estimate the potential worst-case concentrations of the 12 long-lived isotopes in the groundwater under a site with the hydrologic characteristics of the ORR. Of the 12, only 3 isotopes showed any potential to exceed the U.S. Nuclear Regulatory Commission (NRC) 10 Code of Federal Regulations (CFR) Part 20 Drinking Water Limits (DWLs). These isotopes were 14C, 22Na, and 54Mn. The latter two activation products have very short half-lives of 2.6 years and 0.854 year, respectively. Therefore, these will decay before reaching an off-site receptor, and they cannot pose off-site hazards. However, for this extremely conservative model, which overestimates the mobility of the contaminant, 14C, which has a 5,730-year half-life, was shown to represent a potential concern in the context of this study's conservative assumptions. This study examines alternative modifications to the SNS shield berm and makes recommendations.

  15. Fine-tuned SRF activity controls asymmetrical neuronal outgrowth: implications for cortical migration, neural tissue lamination and circuit assembly

    PubMed Central

    Scandaglia, Marilyn; Benito, Eva; Morenilla-Palao, Cruz; Fiorenza, Anna; del Blanco, Beatriz; Coca, Yaiza; Herrera, Eloísa; Barco, Angel

    2015-01-01

    The stimulus-regulated transcription factor Serum Response Factor (SRF) plays an important role in diverse neurodevelopmental processes related to structural plasticity and motile functions, although its precise mechanism of action has not yet been established. To further define the role of SRF in neural development and distinguish between cell-autonomous and non cell-autonomous effects, we bidirectionally manipulated SRF activity through gene transduction assays that allow the visualization of individual neurons and their comparison with neighboring control cells. In vitro assays showed that SRF promotes survival and filopodia formation and is required for normal asymmetric neurite outgrowth, indicating that its activation favors dendrite enlargement versus branching. In turn, in vivo experiments demonstrated that SRF-dependent regulation of neuronal morphology has important consequences in the developing cortex and retina, affecting neuronal migration, dendritic and axonal arborization and cell positioning in these laminated tissues. Overall, our results show that the controlled and timely activation of SRF is essential for the coordinated growth of neuronal processes, suggesting that this event regulates the switch between neuronal growth and branching during developmental processes. PMID:26638868

  16. Melatonin inhibits TPA-induced oral cancer cell migration by suppressing matrix metalloproteinase-9 activation through the histone acetylation

    PubMed Central

    Yeh, Chia-Ming; Lin, Chiao-Wen; Yang, Jia-Sin; Yang, Wei-En; Su, Shih-Chi; Yang, Shun-Fa

    2016-01-01

    Melatonin exerts antimetastatic effects on liver and breast cancer and also inhibits matrix metalloproteinase (MMP) activity. However, the detailed impacts and underlying mechanisms of melatonin on oral cancer cell metastasis are still unclear. This study showed that melatonin attenuated the 12-O-tetradecanoylphorbol-13-acetate-induced migration of oral cancer cell lines, HSC-3 and OECM-1. Zymography, quantitative real-time PCR, and Western blotting analyses revealed that melatonin lessened MMP-9 enzyme activity as well as the expression of MMP-9 mRNA and protein. Furthermore, melatonin suppressed the phosphorylation of the ERK1/2 signalling pathway, which dampened MMP-9 gene transcription by affecting the expression of transcriptional coactivators, such as CREB-binding protein (CREBBP) and E1A binding protein p300 (EP300), and decreasing histone acetylation in HSC-3 and OECM-1 cells. Examinations on clinical samples exhibited that MMP-9, CREBBP, and EP300 were significantly increased in oral cancer tissues. Moreover, the relative level of CREBBP was positively correlated with the expression of MMP-9 and EP300. In conclusion, we demonstrated that melatonin inhibits the motility of HSC-3 and OECM-1 cells in vitro through a molecular mechanism that involves attenuation of MMP-9 expression and activity mediated by decreased histone acetylation. PMID:26980735

  17. Receptor binding and cellular uptake studies of macrophage migration inhibitory factor (MIF): use of biologically active labeled MIF derivatives.

    PubMed

    Kleemann, Robert; Grell, Matthias; Mischke, Ralf; Zimmermann, Gudrun; Bernhagen, Jürgen

    2002-03-01

    Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine for which a receptor has not been identified. That MIF has intracellular functions has been suggested by its enzymatic activity and constitutive expression profile. The discovery of functional MIF-c-Jun activation domain binding protein 1 (JAB1) binding has confirmed this notion and indicated that nonreceptor-based signaling mechanisms are important for MIF function. Here, we have generated and tested several biologically active labeled MIF derivatives to further define target protein binding by MIF and its cellular uptake characteristics. (35)S-MIF, biotinylated MIF, and fluoresceinated MIF were demonstrated to exhibit full biologic activity. Neither by applying a standard iodinated MIF preparation nor by using the biologically active (35)S-MIF derivative in receptor-binding studies were we able to measure any receptor-binding activity on numerous cells, confirming that uptake of MIF into target cells and MIF signaling can occur by receptor-independent pathways. When MIF derivatives were applied in cellular uptake studies, MIF was found to be endocytosed into both immune and nonimmune cells and targeted to the cytosol and lysosomes. The entry of MIF was temperature and energy dependent and was inhibited by monodansylcadaverine but not by ouabain. Endocytosed biotin-MIF bound JAB1 not only in macrophages, as shown previously, but also in nonimmune cells. A tagged MIF construct, MIF-enhanced green fluorescent protein (EGFP), was shown to be a valuable tool, as EGFP constructs of critical MIF cysteine mutants exhibited identical cellular localization properties to those of wild-type MIF (wtMIF). Our results indicate that MIF membrane receptors are not widely expressed, if at all, and suggest that the cellular uptake of MIF occurs by nonreceptor-mediated endocytosis rather than penetration. All the derivatives investigated, except for iodinated MIF, represent valuable tools for further MIF target

  18. The oncoprotein HBXIP up-regulates FGF4 through activating transcriptional factor Sp1 to promote the migration of breast cancer cells.

    PubMed

    Shi, Hui; Li, Yinghui; Feng, Guoxing; Li, Leilei; Fang, Runping; Wang, Zhen; Qu, Jie; Ding, Peijian; Zhang, Xiaodong; Ye, Lihong

    2016-02-26

    We have reported that the oncoprotein hepatitis B X-interacting protein (HBXIP) is able to promote migration of breast cancer cells. Fibroblast growth factor 4 (FGF4) is a multipotent growth factor and is highly expressed in various human cancers. However, the regulatory mechanism of FGF4 in breast cancer remains poorly understood. In the present study, we report that HBXIP is able to up-regulate FGF4 to enhance the migration of breast cancer cells. Immunohistochemistry staining showed that HBXIP and FGF4 were highly expressed in clinical metastatic lymph nodes of breast tumor. The expression levels of HBXIP were positively related to those of FGF4 in clinical breast cancer tissues. Then, we validated that HBXIP up-regulated the expression of FGF4 at the levels of promoter, mRNA and protein by luciferase reporter gene assays, reverse transcription-polymerase chain reaction and Western blot analysis. Moreover, we found that HBXIP was able to activate FGF4 promoter through transcriptional factor Sp1 by luciferase reporter gene assays. Chromatin immunoprecipitation assays confirmed that HBXIP coactivated Sp1 to stimulate FGF4 promoter. In function, we showed that HBXIP promoted breast cancer cell migration through FGF4 by wound healing and transwell cell migration assays. Thus, we conclude that the oncoprotein HBXIP up-regulates FGF4 through activating transcriptional factor Sp1 to promote the migration of breast cancer cells. Therapeutically, HBXIP may serve as a novel target in breast cancer.

  19. Schwann Cell Migration Induced by Earthworm Extract via Activation of PAs and MMP2/9 Mediated through ERK1/2 and p38

    PubMed Central

    Chang, Yung-Ming; Shih, Ying-Ting; Chen, Yueh-Sheng; Liu, Chien-Liang; Fang, Wen-Kuei; Tsai, Chang-Hai; Tsai, Fuu-Jen; Kuo, Wei-Wen; Lai, Tung-Yuan; Huang, Chih-Yang

    2011-01-01

    The earthworm, which has stasis removal and wound-healing functions, is a widely used Chinese herbal medicine in China. Schwann cell migration is critical for the regeneration of injured nerves. Schwann cells provide an essentially supportive activity for neuron regeneration. However, the molecular migration mechanisms induced by earthworms in Schwann cells remain unclear. Here, we investigate the roles of MAPK (ERK1/2, JNK and p38) pathways for earthworm-induced matrix-degrading proteolytic enzyme (PAs and MMP2/9) production in Schwann cells. Moreover, earthworm induced phosphorylation of ERK1/2 and p38, but not JNK, activate the downstream signaling expression of PAs and MMPs in a time-dependent manner. Earthworm-stimulated ERK1/2 and p38 phosphorylation was attenuated by pretreatment with U0126 and SB203580, resulting in migration and uPA-related signal pathway inhibition. The results were confirmed using small interfering ERK1/2 and p38 RNA. These results demonstrated that earthworms can stimulate Schwann cell migration and up-regulate PAs and MMP2/9 expression mediated through the MAPK pathways, ERK1/2 and p38. Taken together, our data suggests the MAPKs (ERK1/2, p38)-, PAs (uPA, tPA)-, MMP (MMP2, MMP9) signaling pathway of Schwann cells regulated by earthworms might play a major role in Schwann cell migration and nerve regeneration. PMID:19808845

  20. Hypoxia/reoxygenation-experienced cancer cell migration and metastasis are regulated by Rap1- and Rac1-GTPase activation via the expression of thymosin beta-4.

    PubMed

    Lee, Jae-Wook; Ryu, Yun-Kyoung; Ji, Young-Hoon; Kang, Joo Hyun; Moon, Eun-Yi

    2015-01-01

    Signaling by small guanosine triphosphatases (GTPase), Rap1/Rac1, is one of the major pathways controlling cancer cell migration and tumor metastasis. Thymosin beta-4 (Tβ4), an actin-sequestering protein, has been shown to increase migration of cancer cells. Episodes of hypoxia and re-oxygenation (H/R) are an important phenomenon in tumor microenvironment (TME). We investigated whether Tβ4 could play as an intermediary to crosstalk between Rac1- and Rap1- GTPase activation under hypoxia/reoxygenation (H/R) conditions. Inhibition of Tβ4 expression using transcription activator-like effector nucleases (TALEN) significantly decreased lung metastasis of B16F10 cells. Rac1 and Rap1 activity, as well as cancer cell migration, increased following induction of Tβ4 expression in normoxia- or H/R-experienced cells, but were barely detectable in Tβ4-depleted cells. Rap1-regulated Rac1 activity was decreased by a dominant negative Rap1 (Rap1N17), and increased by 8-(4-chloro-phenylthio)-2'-O-methyladenosine-3',5'-cyclic monophosphate (CPT), a Rap1 activator. In contrast, a Rac1-specific inhibitor, NSC23766, and dominant negative Rac1 (Rac1N17) enhanced Tβ4 expression and aberrant Rap1 activity. While NSC23766 and Rac1N17 incompletely inhibited tumor metastasis in vivo, and H/R-experienced cancer cell migration in vitro, more efficient attenuation of cancer cell migration was accomplished by simultaneous inactivation of Rap1 and Rac1 with Rap1N17 and Rac1N17, respectively. These data suggest that a combination therapy targeting both Rap1 and Rac1 activity may be an effective method of inhibiting tumor metastasis.

  1. ApoER2 and Reelin are expressed in regenerating peripheral nerve and regulate Schwann cell migration by activating the Rac1 GEF protein, Tiam1.

    PubMed

    Pasten, Consuelo; Cerda, Joaquín; Jausoro, Ignacio; Court, Felipe A; Cáceres, Alfredo; Marzolo, Maria-Paz

    2015-11-01

    ApoER2 and its ligand Reelin participate in neuronal migration during development. Upon receptor binding, Reelin induces the proteolytic processing of ApoER2 as well as the activation of signaling pathway, including small Rho GTPases. Besides its presence in the central nervous system (CNS), Reelin is also secreted by Schwann cells (SCs), the glial cells of the peripheral nervous system (PNS). Reelin deficient mice (reeler) show decreased axonal regeneration in the PNS; however neither the presence of ApoER2 nor the role of the Reelin signaling pathway in the PNS have been evaluated. Interestingly SC migration occurs during PNS development and during injury-induced regeneration and involves activation of small Rho GTPases. Thus, Reelin-ApoER2 might regulate SC migration during axon regeneration in the PNS. Here we demonstrate the presence of ApoER2 in PNS. After sciatic nerve injury Reelin was induced and its receptor ApoER2 was proteolytically processed. In vitro, SCs express both Reelin and ApoER2 and Reelin induces SC migration. To elucidate the molecular mechanism underlying Reelin-dependent SC migration, we examined the involvement of Rac1, a conspicuous small GTPase family member. FRET experiments revealed that Reelin activates Rac1 at the leading edge of SCs. In addition, Tiam1, a major Rac1-specific GEF was required for Reelin-induced SC migration. Moreover, Reelin-induced SC migration was decreased after suppression of the polarity protein PAR3, consistent with its association to Tiam1. Even more interesting, we demonstrated that PAR3 binds preferentially to the full-length cytoplasmic tail of ApoER2 corresponding to the splice-variant containing the exon 19 that encodes a proline-rich insert and that ApoER2 was required for SC migration. Our study reveals a novel function for Reelin/ApoER2 in PNS, inducing cell migration of SCs, a process relevant for PNS development and regeneration.

  2. Autocrine EGF receptor activation mediates endothelial cell migration and vascular morphogenesis induced by VEGF under interstitial flow

    SciTech Connect

    Semino, Carlos E. . E-mail: semino@mit.edu; Kamm, Roger D.; Lauffenburger, Douglas A.

    2006-02-01

    We show here that autocrine ligand activation of epidermal growth factor (EGF) receptor in combination with interstitial flow is critically involved in the morphogenetic response of endothelial cells to VEGF stimulation. Human umbilical vein endothelial cell (HUVEC) monolayers cultured on a collagen gel and exposed to low interstitial flow in the absence of EGF and VEGF remained viable and mitotic but exhibited little evidence of vascular morphogenesis. Addition of VEGF produced a flow-dependent morphogenetic response within 48 to 72 h, characterized by branched capillary-like structures. The response was substantially abolished by inhibitors related to the autocrine EGF receptor pathway including Galardin, AG1478, PD98059, and an EGF receptor-blocking antibody, indicating that regulation of the morphogenetic process operates via autocrine EGF receptor activation. Moreover, we observed that in our system the EGF receptor was always activated independently of the interstitial flow, and, in addition, the EGF receptor inhibitors used above reduced the phosphorylation state of the receptor, correlating with inhibition of capillary morphogenesis. Finally, 5'bromo-2'-deoxyuridine (BrdU) labeling identified dividing cells at the monolayer but not in the extending capillary-like structures. EGF pathway inhibitors Galardin and AG1478 did not reduce BrdU incorporation in the monolayer, indicating that the EGF-receptor-mediated morphogenetic behavior is mainly due to cell migration rather than proliferation. Based on these results, we propose a two-step model for in vitro capillary morphogenesis in response to VEGF stimulation with interstitial fluid flow: monolayer maintenance by mitotic activity independent of EGF receptors and a migratory response mediated by autocrine EGF receptor activation wherein cells establish capillary-like structures.

  3. TGF-β1-induced EMT promotes targeted migration of breast cancer cells through the lymphatic system by the activation of CCR7/CCL21-mediated chemotaxis.

    PubMed

    Pang, M-F; Georgoudaki, A-M; Lambut, L; Johansson, J; Tabor, V; Hagikura, K; Jin, Y; Jansson, M; Alexander, J S; Nelson, C M; Jakobsson, L; Betsholtz, C; Sund, M; Karlsson, M C I; Fuxe, J

    2016-02-11

    Tumor cells frequently disseminate through the lymphatic system during metastatic spread of breast cancer and many other types of cancer. Yet it is not clear how tumor cells make their way into the lymphatic system and how they choose between lymphatic and blood vessels for migration. Here we report that mammary tumor cells undergoing epithelial-mesenchymal transition (EMT) in response to transforming growth factor-β (TGF-β1) become activated for targeted migration through the lymphatic system, similar to dendritic cells (DCs) during inflammation. EMT cells preferentially migrated toward lymphatic vessels compared with blood vessels, both in vivo and in 3D cultures. A mechanism of this targeted migration was traced to the capacity of TGF-β1 to promote CCR7/CCL21-mediated crosstalk between tumor cells and lymphatic endothelial cells. On one hand, TGF-β1 promoted CCR7 expression in EMT cells through p38 MAP kinase-mediated activation of the JunB transcription factor. Blockade of CCR7, or treatment with a p38 MAP kinase inhibitor, reduced lymphatic dissemination of EMT cells in syngeneic mice. On the other hand, TGF-β1 promoted CCL21 expression in lymphatic endothelial cells. CCL21 acted in a paracrine fashion to mediate chemotactic migration of EMT cells toward lymphatic endothelial cells. The results identify TGF-β1-induced EMT as a mechanism, which activates tumor cells for targeted, DC-like migration through the lymphatic system. Furthermore, it suggests that p38 MAP kinase inhibition may be a useful strategy to inhibit EMT and lymphogenic spread of tumor cells.

  4. SYNTHESIS AND MIGRATION OF PROTEINS IN THE CELLS OF THE EXOCRINE PANCREAS AS REVEALED BY SPECIFIC ACTIVITY DETERMINATION FROM RADIOAUTOGRAPHS

    PubMed Central

    Warshawsky, H.; Leblond, C. P.; Droz, B.

    1963-01-01

    Radioautographs of pancreatic acinar cells were prepared in rats and mice sacrificed at various times after injection of leucine-, glycine-, or methionine-H3. Measurements of radioactivity concentration (number of silver grains per unit area) and relative protein concentration (by microspectrophotometry of Millon-treated sections) yielded the mean specific activity of proteins in various regions of the acinar cells. The 2 to 5 minute radioautographs as well as the specific activity time curves demonstrate protein synthesis in ergastoplasm. From there, most newly synthesized proteins migrate to and accumulate in the Golgi zone. Then they spread to the whole zymogen region and, finally, enter the excretory ducts. An attempt at estimating turnover times indicated that two classes of proteins are synthesized in the ergastoplasm: "sedentary" with a slow turnover (62.5 hours) and "exportable" with rapid turnover (4.7 minutes). It is estimated that the exportable proteins spend approximately 11.7 minutes in the Golgi zone where they are built up into zymogen granules, and thereafter 36.0 minutes as fully formed zymogen granules, before they are released outside the acinar cell as pancreatic secretion. The mean life span of a zymogen granule in the cell is estimated to be 47.7 minutes. PMID:13999005

  5. Synaptic Plasticity Selectively Activated by Polarization-Dependent Energy-Efficient Ion Migration in an Ultrathin Ferroelectric Tunnel Junction.

    PubMed

    Yoon, Chansoo; Lee, Ji Hye; Lee, Sangik; Jeon, Ji Hoon; Jang, Jun Tae; Kim, Dae Hwan; Kim, Young Heon; Park, Bae Ho

    2017-03-08

    Selectively activated inorganic synaptic devices, showing a high on/off ratio, ultrasmall dimensions, low power consumption, and short programming time, are required to emulate the functions of high-capacity and energy-efficient reconfigurable human neural systems combining information storage and processing ( Li et al. Sci. Rep. 2014 , 4 , 4096 ). Here, we demonstrate that such a synaptic device is realized using a Ag/PbZr0.52Ti0.48O3 (PZT)/La0.8Sr0.2MnO3 (LSMO) ferroelectric tunnel junction (FTJ) with ultrathin PZT (thickness of ∼4 nm). Ag ion migration through the very thin FTJ enables a large on/off ratio (10(7)) and low energy consumption (potentiation energy consumption = ∼22 aJ and depression energy consumption = ∼2.5 pJ). In addition, the simple alignment of the downward polarization in PZT selectively activates the synaptic plasticity of the FTJ and the transition from short-term plasticity to long-term potentiation.

  6. Γ-Ionizing radiation-induced activation of the EGFR-p38/ERK-STAT3/CREB-1-EMT pathway promotes the migration/invasion of non-small cell lung cancer cells and is inhibited by podophyllotoxin acetate.

    PubMed

    Cho, Jeong Hyun; Hong, Wan Gi; Jung, Yu-Jin; Lee, Jaeseok; Lee, Eunah; Hwang, Sang-Gu; Um, Hong-Duck; Park, Jong Kuk

    2016-06-01

    Here, we report a new intracellular signaling pathway involved in γ-ionizing radiation (IR)-induced migration/invasion and show that podophyllotoxin acetate (PA) inhibits the IR-induced invasion and migration of A549 cells (a non-small cell lung cancer (NSCLC) cell line). Our results revealed that IR increased the invasion/migration of A549 cells, and this effect was decreased by 10 nM PA treatment. PA also inhibited the expressions/activities of matrix metalloprotase (MMP) -2, MMP-9, and vimentin, suggesting that PA could block the IR-induced epithelial-mesenchymal transition (EMT). The IR-induced increases in invasion/migration were associated with the activation of EGFR-AKT, and PA inhibited this effect. P38 and p44/42 ERK were also involved in IR-induced invasion/migration, and combined treatments with PA plus inhibitors of each MAPK synergistically blocked this invasion/migration. In terms of transcription factors (TFs), IR-induced increases in cyclic AMP response element-binding protein-1 (CREB-1) and signal transducer and activator of transcription 3 (STAT3) increased invasion/migration and EMT. PA also inhibited these transcription factors and then blocked IR-induced invasion/migration. Collectively, these results indicate that IR induces cancer cell invasion/migration by activating the EGFR-p38/ERK-CREB-1/STAT3-EMT pathway and that PA blocks this pathway to inhibit IR-induced invasion/migration.

  7. Gβ1 controls collective cell migration by regulating the protrusive activity of leader cells in the posterior lateral line primordium.

    PubMed

    Xu, Hui; Ye, Ding; Behra, Martine; Burgess, Shawn; Chen, Songhai; Lin, Fang

    2014-01-15

    Collective cell migration is critical for normal development, tissue repair and cancer metastasis. Migration of the posterior lateral line primordium (pLLP) generates the zebrafish sensory organs (neuromasts, NMs). This migration is promoted by the leader cells at the leading edge of the pLLP, which express the G protein-coupled chemokine receptor Cxcr4b and respond to the chemokine Cxcl12a. However, the mechanism by which Cxc112a/Cxcr4b signaling regulates pLLP migration remains unclear. Here we report that signal transduction by the heterotrimeric G protein subunit Gβ1 is essential for proper pLLP migration. Although both Gβ1 and Gβ4 are expressed in the pLLP and NMs, depletion of Gβ1 but not Gβ4 resulted in an arrest of pLLP migration. In embryos deficient for Gβ1, the pLLP cells migrated in an uncoordinated fashion and were unable to extend protrusions at the leading front, phenocopying those in embryos deficient for Cxcl12a or Cxcr4b. A transplantation assay showed that, like Cxcr4b, Gβ1 is required only in the leader cells of the pLLP. Analysis of F-actin dynamics in the pLLP revealed that whereas wild-type leader cells display extensive actin polymerization in the direction of pLLP migration, counterparts defective for Gβ1, Cxcr4b or Cxcl12a do not. Finally, synergy experiments revealed that Gβ1 and Cxcr4b interact genetically in regulating pLLP migration. Collectively, our data indicate that Gβ1 controls migration of the pLLP, likely by acting downstream of the Cxcl12a/Cxcr4b signaling. This study also provides compelling evidence for functional specificity among Gβ isoforms in vivo.

  8. Intermediate-conductance Calcium-activated Potassium Channel KCa3.1 and Chloride Channel Modulate Chemokine Ligand (CCL19/CCL21)-induced Migration of Dendritic Cells

    PubMed Central

    Shao, Zhifei; Gaurav, Rohit; Agrawal, Devendra K

    2014-01-01

    The role of ion channels is largely unknown in chemokine-induced migration in non-excitable cells such as dendritic cells. Here, we examined the role of KCa3.1 and chloride channels in lymphatic chemokines-induced migration of dendritic cells. The amplitude and kinetics of CCL19/21-induced Ca2+ influx were associated with CCR7 expression levels, extracellular free Ca2+ and Cl−, and independent of extracellular K+. Chemokines, CCL19 and CCL21, and KCa3.1 activator, 1-EBIO, induced plasma membrane hyperpolarization and K+ efflux, which was blocked by TRAM-34, suggesting that KCa3.1 carried larger conductance than the inward CRAC. Blockade of KCa3.1, low Cl− in the medium, and low dose of DIDS impaired CCL19/CCL21-induced Ca2+ influx, cell volume change, and DC migration. High doses of DIDS completely blocked DC migration possibly by significantly disrupting mitochondrial membrane potential. In conclusion, KCa3.1 and chloride channel are critical in human DC migration by synergistically regulating membrane potential, chemokine-induced Ca2+ influx, and cell volume. PMID:25583444

  9. Activated α2 -Macroglobulin Induces Mesenchymal Cellular Migration Of Raw264.7 Cells Through Low-Density Lipoprotein Receptor-Related Protein 1.

    PubMed

    Ferrer, Darío G; Dato, Virginia Actis; Fincati, Javier R Jaldín; Lorenc, Valeria E; Sánchez, María C; Chiabrando, Gustavo A

    2016-12-24

    Distinct modes of cell migration contribute to diverse types of cell movements. The mesenchymal mode is characterized by a multistep cycle of membrane protrusion, the formation of focal adhesion, and the stabilization at the leading edge associated with the degradation of extracellular matrix (ECM) components and with regulated extracellular proteolysis. Both α2 -Macroglobulin (α2 M) and its receptor, low density lipoprotein receptor-related protein 1 (LRP1), play important roles in inflammatory processes, by controlling the extracellular activity of several proteases. The binding of the active form of α2 M (α2 M*) to LRP1 can also activate different signaling pathways in macrophages, thus inducing extracellular matrix metalloproteinase-9 (MMP-9) activation and cellular proliferation. In the present study, we investigated whether the α2 M*/LRP1 interaction induces cellular migration of the macrophage-derived cell line, Raw264.7. By using the wound-scratch migration assay and confocal microscopy, we demonstrate that α2 M* induces LRP1-mediated mesenchymal cellular migration. This migration exhibits the production of enlarged cellular protrusions, MT1-MMP distribution to these leading edge protrusions, actin polymerization, focal adhesion formation, and increased intracellular LRP1/β1-integrin colocalization. Moreover, the presence of calphostin-C blocked the α2 M*-stimulated cellular protrusions, suggesting that the PKC activation is involved in the cellular motility of Raw264.7 cells. These findings could constitute a therapeutic target for inflammatory processes with deleterious consequences for human health, such as rheumatoid arthritis, atherosclerosis and cancer. J. Cell. Biochem. 9999: 1-9, 2017. © 2016 Wiley Periodicals, Inc.

  10. Differing requirements for CCR4, E-selectin, and α4β1 for the migration of memory CD4 and activated T cells to dermal inflammation.

    PubMed

    Gehad, Ahmed; Al-Banna, Nadia A; Vaci, Maria; Issekutz, Andrew C; Mohan, Karkada; Latta, Markus; Issekutz, Thomas B

    2012-07-01

    CCR4 on T cells is suggested to mediate skin homing in mice. Our objective was to determine the interaction of CCR4, E-selectin ligand (ESL), and α(4)β(1) on memory and activated T cells in recruitment to dermal inflammation. mAbs to rat CCR4 were developed. CCR4 was on 5-21% of memory CD4 cells, and 20% were also ESL(+). Anti-TCR-activated CD4 and CD8 cells were 40-55% CCR4(+), and ∼75% of both CCR4(+) and CCR4(-) cells were ESL(+). CCR4(+) memory CD4 cells migrated 4- to 7-fold more to dermal inflammation induced by IFN-γ, TNF, TLR agonists, and delayed-type hypersensitivity than CCR4(-) cells. CCR4(+) activated CD4 cells migrated only 5-50% more than CCR4(-) cells to these sites. E-selectin blockade inhibited ∼60% of CCR4(+) activated CD4 cell migration but was less effective on memory cells where α(4)β(1) was more important. Anti-α(4)β(1) also inhibited CCR4(-) activated CD4 cells more than CCR4(+) cells. Anti-E-selectin reduced activated CD8 more than CD4 cell migration. These findings modify our understanding of CCR4, ESL, α(4)β(1), and dermal tropism. There is no strict relationship between CCR4 and ESL for skin homing of CD4 cells, because the activation state and inflammatory stimulus are critical determinants. Dermal homing memory CD4 cells express CCR4 and depend more on α(4)β(1) than ESL. Activated CD4 cells do not require CCR4, but CCR4(+) cells are more dependent on ESL than on α(4)β(1), and CCR4(-) cells preferentially use α(4)β(1). The differentiation from activated to memory CD4 cells increases the dependence on CCR4 for skin homing and decreases the requirement for ESL.

  11. Conservation physiology of animal migration

    PubMed Central

    Lennox, Robert J.; Chapman, Jacqueline M.; Souliere, Christopher M.; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D.; Cooke, Steven J.

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  12. Conservation physiology of animal migration.

    PubMed

    Lennox, Robert J; Chapman, Jacqueline M; Souliere, Christopher M; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D; Cooke, Steven J

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  13. Active CO2 Reservoir Management: A Strategy for Controlling Pressure, CO2 and Brine Migration in Saline-Formation CCS

    NASA Astrophysics Data System (ADS)

    Buscheck, T. A.; Sun, Y.; Hao, Y.; Court, B.; Celia, M. A.; Wolery, T.; Tompson, A. F.; Aines, R. D.; Friedmann, J.

    2010-12-01

    CO2 capture and sequestration (CCS) in deep geological formations is regarded as a promising means of lowering the amount of CO2 emitted to the atmosphere and thereby mitigate global warming. The most promising systems for CCS are depleted oil reservoirs, particularly those suited to CO2-based Enhanced Oil Recovery (CCS-EOR), and deep saline formations, both of which are well separated from the atmosphere. For conventional, industrial-scale, saline-formation CCS, pressure buildup can have a limiting effect on CO2 storage capacity. To address this concern, we analyze Active CO2 Reservoir Management (ACRM), which combines brine extraction and residual-brine reinjection with CO2 injection, comparing it with conventional saline-formation CCS. We investigate the influence of brine extraction on pressure response and CO2 and brine migration using the NUFT code. By extracting brine from the lower portion of the storage formation, from locations progressively further from the center of injection, we can counteract buoyancy that drives CO2 to the top of the formation, which is useful in dipping formations. Using “push-pull” manipulation of the CO2 plume, we expose less of the caprock seal to CO2 and more of the storage formation to CO2, with more of the formation utilized for trapping mechanisms. Plume manipulation can also counteract the influence of heterogeneity. We consider the impact of extraction ratio, defined as net extracted brine volume (extraction minus reinjection) divided by injected CO2 volume. Pressure buildup is reduced with increasing extraction ratio, which reduces CO2 and brine migration, increases CO2 storage capacity, and reduces other risks, such as leakage up abandoned wells, caprock fracturing, fault activation, and induced seismicity. For a 100-yr injection period, a 10-yr delay in brine extraction does not diminish the magnitude of pressure reduction. Moreover, it is possible to achieve pressure management with just a few brine-extraction wells

  14. Role of I-TAC-binding receptors CXCR3 and CXCR7 in proliferation, activation of intracellular signaling pathways and migration of various tumor cell lines.

    PubMed

    Miekus, Katarzyna; Jarocha, Danuta; Trzyna, Elzbieta; Majka, Marcin

    2010-01-01

    Chemokines and its receptors stimulate tumor growth, migration and invasion. In this study we evaluated the expression and function of CXCR3 and CXCR7 receptors in cervical carcinoma, rhabdomyosarcoma and glioblastoma cell lines. We found that both receptors were expressed at different degree by tumor cells. CXCR7 was expressed at both mRNA and protein level by all tumor cell lines. The expression of CXCR7 differed between rhabdomyosarcoma subtypes. The receptor was highly expressed in alveolar rhabdomyosarcoma and the expression was low in embryonal rhabdomyosarcoma. The expression of CXCR3 was low in majority of the tumor cell lines. Upon I-TAC stimulation AKT and MAPK kinases were activated. However, the activation of growth promoting pathways did not increased the proliferation rate of tumor cells. Since chemokines stimulate the migration of various cell types the ability of I-TAC to stimulate migration of tumor cells were studied. We did not observe the migration of tumor cells toward I-TAC gradient alone. However, at the low dose, I-TAC sensitized tumor cells toward SDF-1beta gradient and synergized with SDF-1beta in activation of intracellular pathways. Our data suggest an important role of I-TAC and its receptors in biology of solid tumors and we postulate that I-TAC-binding receptors might be used as the potential targets for antitumor therapy.

  15. The effect of catalase on migration and invasion of lung cancer cells by regulating the activities of cathepsin S, L, and K.

    PubMed

    Tsai, Ju-Ying; Lee, Mon-Juan; Dah-Tsyr Chang, Margaret; Huang, Haimei

    2014-04-15

    Abundant clinical evidences indicate that up-regulation of several cathepsins in many human cancers is correlated with malignant progression and poor patient prognosis. In addition, a decrease in catalase activity or accumulation of hydrogen peroxide correlates with cancer metastasis. Recent studies indicate that cathepsin activation and expression can be modulated via H2O2 treatment. However, the actual relationship between catalase and cathepsins is not yet fully understood. In the present study, we found that catalase expression (or activity) was higher, while intracellular and extracellular Cat S, Cat L, and Cat K activities were lower in the non-invasive CL1-0 cells compared to the highly invasive CL1-5 cells. After CL1-0 cells were transfected with catalase-shRNA, the corresponding ROS (H2O2) level and Cat S, Cat L, or Cat K expression (or activity) was up-regulated, accompanied by an increase in cell migration and invasion. On the other hand, ROS (H2O2) level, cathepsin S, L, and K activities, cell migration and invasion were decreased in catalase-overexpressed CL1-5 cells. It is suggested that catalase may regulate cathepsin activity by controlling the production of ROS (H2O2), leading to variation in migration and invasion ability of lung cancer cells.

  16. Umbilical cord-derived mesenchymal stem cells promote proliferation and migration in MCF-7 and MDA-MB-231 breast cancer cells through activation of the ERK pathway.

    PubMed

    Li, Tao; Zhang, Chunfu; Ding, Yanling; Zhai, Wei; Liu, Kui; Bu, Fan; Tu, Tao; Sun, Lingxian; Zhu, Wei; Zhou, Fangfang; Qi, Wenkai; Hu, Jiabo; Chen, Huabiao; Sun, Xiaochun

    2015-09-01

    Mesenchymal stem cells (MSCs) are known to migrate to tumor tissues and to play an important role in cancer progression. However, the effects of MSCs on tumor progression remain controversial. The purpose of the present study was to detect the effects of human umbilical cord-derived MSCs (hUC‑MSCs) on the human breast cancer cell lines MDA-MB‑231 and MCF-7 in vitro and the underlying mechanisms. MSCs were isolated and identified from umbilical cord tissues. MDA-MB‑231 and MCF-7 cells were treated with conditioned medium (CM) from 10 and 20% umbilical cord MSCs (UC-MSCs), and the resulting changes in proliferation and migration were investigated. The 3-(4,5-dimethyl-2-thiazolyl)‑2,5-diphenyl‑2-H-tetrazolium bromide (MTT) and plate clone formation assays were used to assess the effect on proliferation, and the effects of CM on MDA-MB-231 and MCF-7 migration were assessed through scratch wound and Transwell migration assays. The expression of cell proliferation- and metastasis-related genes and proteins and activation of the ERK signaling pathway were analyzed by RT-PCR and western blot assays. UC-MSCs are characteristically similar to bone marrow MSCs (BM-MSCs) and exhibit multipotential differentiation capability (i.e., osteoblasts and adipocytes). The MTT, plate clone formation, scratch wound and Transwell migration assay results revealed that 10 and 20% CM promoted the proliferation and migration to higher levels than those observed in the control group. Our findings showed that UC-MSC-CM inhibited E-cadherin expression, increased the expression of N-cadherin and proliferating cell nuclear antigen (PCNA) and enhanced the expression of ZEB1, a transcription factor involved in epithelial‑to‑mesenchymal transition (EMT), through activation of the ERK pathway. U0126, an inhibitor of ERK, reversed the effects of UC-MSC-CM on breast cancer cell proliferation and migration. We conclude that UC-MSCs promote the proliferation and migration of breast

  17. Effects of rosuvastatin on the production and activation of matrix metalloproteinase-2 and migration of cultured rat vascular smooth muscle cells induced by homocysteine*

    PubMed Central

    Shi, Ya-fei; Chi, Ju-fang; Tang, Wei-liang; Xu, Fu-kang; Liu, Long-bin; Ji, Zheng; Lv, Hai-tao; Guo, Hang-yuan

    2013-01-01

    Objective: To test the influence of homocysteine on the production and activation of matrix metalloproteinase-2 (MMP-2) and tissue inhibitors of matrix metalloproteinase-2 (TIMP-2) and on cell migration of cultured rat vascular smooth muscle cells (VSMCs). Also, to explore whether rosuvastatin can alter the abnormal secretion and activation of MMP-2 and TIMP-2 and migration of VSMCs induced by homocysteine. Methods: Rat VSMCs were incubated with different concentrations of homocysteine (50–5 000 μmol/L). Western blotting and gelatin zymography were used to investigate the expressions and activities of MMP-2 and TIMP-2 in VSMCs in culture medium when induced with homocysteine for 24, 48, and 72 h. Transwell chambers were employed to test the migratory ability of VSMCs when incubated with homocysteine for 48 h. Different concentrations of rosuvastatin (10−9–10−5 mol/L) were added when VSMCs were induced with 1 000 μmol/L homocysteine. The expressions and activities of MMP-2 and TIMP-2 were examined after incubating for 24, 48, and 72 h, and the migration of VSMCs was also examined after incubating for 48 h. Results: Homocysteine (50–1 000 μmol/L) increased the production and activation of MMP-2 and expression of TIMP-2 in a dose-dependent manner. However, when incubated with 5 000 μmol/L homocysteine, the expression of MMP-2 was up-regulated, but its activity was down-regulated. Increased homocysteine-induced production and activation of MMP-2 were reduced by rosuvastatin in a dose-dependent manner whereas secretion of TIMP-2 was not significantly altered by rosuvastatin. Homocysteine (50–5 000 μmol/L) stimulated the migration of VSMCs in a dose-dependent manner, but this effect was eliminated by rosuvastatin. Conclusions: Homocysteine (50–1 000 μmol/L) significantly increased the production and activation of MMP-2, the expression of TIMP-2, and the migration of VSMCs in a dose-dependent manner. Additional extracellular rosuvastatin can decrease

  18. PCTK3/CDK18 regulates cell migration and adhesion by negatively modulating FAK activity

    PubMed Central

    Matsuda, Shinya; Kawamoto, Kohei; Miyamoto, Kenji; Tsuji, Akihiko; Yuasa, Keizo

    2017-01-01

    PCTAIRE kinase 3 (PCTK3) is a member of the cyclin dependent kinase family, but its physiological function remains unknown. We previously reported that PCTK3-knockdown HEK293T cells showed actin accumulation at the leading edge, suggesting that PCTK3 is involved in the regulation of actin reorganization. In this study, we investigated the physiological function and downstream signal transduction molecules of PCTK3. PCTK3 knockdown in HEK293T cells increased cell motility and RhoA/Rho-associated kinase activity as compared with control cells. We also found that phosphorylation at residue Tyr-397 in focal adhesion kinase (FAK) was increased in PCTK3-knockdown cells. FAK phosphorylation at Tyr-397 was increased in response to fibronectin stimulation, whereas its phosphorylation was suppressed by PCTK3. In addition, excessive expression of PCTK3 led to the formation of filopodia during the early stages of cell adhesion in HeLa cells. These results indicate that PCTK3 controls actin cytoskeleton dynamics by negatively regulating the FAK/Rho signaling pathway. PMID:28361970

  19. Thyroid hormone receptor inhibits hepatoma cell migration through transcriptional activation of Dickkopf 4

    SciTech Connect

    Chi, Hsiang-Cheng; Liao, Chen-Hsin; Huang, Ya-Hui; Wu, Sheng-Ming; Tsai, Chung-Ying; Liao, Chia-Jung; Tseng, Yi-Hsin; Lin, Yang-Hsiang; Chen, Cheng-Yi; Chung, I-Hsiao; Wu, Tzu-I; Chen, Wei-Jan; Lin, Kwang-Huei

    2013-09-13

    Highlights: •T{sub 3} affects DKK4 mRNA and protein expression in HepG2-TR cells. •Regulation of DKK4 by T{sub 3} is at transcriptional level. •DKK4 overexpression suppresses hepatoma cell metastasis. -- Abstract: Triiodothyronine (T{sub 3}) is a potent form of thyroid hormone mediates several physiological processes including cellular growth, development, and differentiation via binding to the nuclear thyroid hormone receptor (TR). Recent studies have demonstrated critical roles of T{sub 3}/TR in tumor progression. Moreover, long-term hypothyroidism appears to be associated with the incidence of human hepatocellular carcinoma (HCC), independent of other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein that antagonizes the canonical Wnt signaling pathway, is induced by T{sub 3} at both mRNA and protein levels in HCC cell lines. However, the mechanism underlying T{sub 3}-mediated regulation of DKK4 remains unknown. In the present study, the 5′ promoter region of DKK4 was serially deleted, and the reporter assay performed to localize the T{sub 3} response element (TRE). Consequently, we identified an atypical direct repeat TRE between nucleotides −1645 and −1629 conferring T{sub 3} responsiveness to the DKK4 gene. This region was further validated using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Stable DKK4 overexpression in SK-Hep-1 cells suppressed cell invasion and metastatic potential, both in vivo andin vitro, via reduction of matrix metalloproteinase-2 (MMP-2) expression. Our findings collectively suggest that DKK4 upregulated by T{sub 3}/TR antagonizes the Wnt signal pathway to suppress tumor cell progression, thus providing new insights into the molecular mechanism underlying thyroid hormone activity in HCC.

  20. Expression/activation of α5β1 integrin is linked to the β-catenin signaling pathway to drive migration in glioma cells

    PubMed Central

    Renner, Guillaume; Noulet, Fanny; Mercier, Marie-Cécile; Choulier, Laurence; Etienne-Selloum, Nelly; Gies, Jean-Pierre; Lehmann, Maxime; Lelong-Rebel, Isabelle; Martin, Sophie; Dontenwill, Monique

    2016-01-01

    The Wnt/beta catenin pathway has been highlighted as an important player of brain tumors aggressiveness and resistance to therapies. Increasing knowledges of the regulation of beta-catenin transactivation point out its hub position in different pathophysiological outcomes in glioma such as survival and migration. Crosstalks between integrins and beta-catenin pathways have been suggested in several tumor tissues. As we demonstrated earlier that α5β1 integrin may be considered as a therapeutic target in high grade glioma through its contribution to glioma cell migration and resistance to chemotherapy, we addressed here the potential relationship between α5β1 integrin and beta-catenin activation in glioma cells. We demonstrated that overexpression and activation by fibronectin of α5β1 integrin allowed the transactivation of beta-catenin gene targets included in an EMT-like program that induced an increase in cell migration. Hampering of beta catenin activation and cell migration could be similarly achieved by a specific integrin antagonist. In addition we showed that α5β1 integrin/AKT axis is mainly involved in these processes. However, blockade of beta-catenin by XAV939 (tankyrase inhibitor leading to beta-catenin degradation) did not synergize with p53 activation aiming to cell apoptosis as was the case with integrin antagonists. We therefore propose a dual implication of α5β1 integrin/AKT axis in glioma cell resistance to therapies and migration each supported by different signaling pathways. Our data thus suggest that α5β1 integrin may be added to the growing list of beta-catenin modulators and provide new evidences to assign this integrin as a valuable target to fight high grade glioma. PMID:27613837

  1. Activation of the Farnesoid X-receptor in breast cancer cell lines results in cytotoxicity but not increased migration potential.

    PubMed

    Alasmael, Noura; Mohan, Rati; Meira, Lisiane B; Swales, Karen E; Plant, Nick J

    2016-01-28

    Breast cancer is the commonest form of cancer in women, but successful treatment is confounded by the heterogeneous nature of breast tumours: Effective treatments exist for hormone-sensitive tumours, but triple-negative breast cancer results in poor survival. An area of increasing interest is metabolic reprogramming, whereby drug-induced alterations in the metabolic landscape of a tumour slow tumour growth and/or increase sensitivity to existing therapeutics. Nuclear receptors are transcription factors central to the expression of metabolic and transport proteins, and thus represent potential targets for metabolic reprogramming. We show that activation of the nuclear receptor FXR, either by its endogenous ligand CDCA or the synthetic GW4064, leads to cell death in four breast cancer cell lines with distinct phenotypes: MCF-10A (normal), MCF-7 (receptor positive), MDA-MB-231 and MDA-MB-468 (triple negative). Furthermore, we show that the mechanism of cell death is predominantly through the intrinsic apoptotic pathway. Finally, we demonstrate that FXR agonists do not stimulate migration in breast cancer cell lines, an important potential adverse effect. Together, our data support the continued examination of FXR agonists as a novel class of therapeutics for the treatment of breast cancer.

  2. Long-term characterization, lagoon treatment and migration potential of landfill leachate: a case study in an active Italian landfill.

    PubMed

    Frascari, D; Bronzini, F; Giordano, G; Tedioli, G; Nocentini, M

    2004-01-01

    The elaboration of 10 years of monitoring of leachate quality and quantity, leachate treatment and degree of contamination of soil and surface waters at the Tre Monti site--an active, 4-million-m(3) landfill in Northern Italy--is presented in this study. A hydrological model of leachate production is applied, with a good match of the experimental data. The concentrations of all leachate components except sulfate are characterized by fluctuations over a constant or increasing value. Different ways of interpreting leachate quality data are discussed; the elaboration indicates that the pollutant load on the leachate treatment facility will remain basically constant as long as waste will be added to the landfill. The analysis of the data relative to 10 years of leachate pre-treatment in the adjoining, non-aerated lagoon system indicates that a significant removal is achieved for most leachate components; the operational conditions of the plant are described, and the removal mechanisms are discussed. Finally, the potential for contamination of soil and surface waters is examined by analyzing long-term quality trends of the sub-superficial waters sampled near the lagoons and by means of an analytical campaign conducted on clay cores sampled near and underneath the treatment ponds. The experimental values indicate that the clay layer located under the entire site offers an effective barrier to the migration of leachate contaminants.

  3. Age, Episodicity and Migration of Hydrothermal Activity within the Axial Valley, Endeavour Segment, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Jamieson, J. W.; Hannington, M. D.; Kelley, D. S.; Clague, D. A.; Holden, J. F.; Tivey, M. K.; Delaney, J. R.

    2011-12-01

    Hydrothermal sulfide deposits record the history of high-temperature venting along the Endeavour Segment. Active venting is currently located within five discreet vent fields, with minor diffuse venting occurring between the fields. However, inactive and/or extinct sulfide structures are found throughout the entire axial valley of the ridge segment, suggesting that hydrothermal activity has been more vigorous in the past or focused venting has migrated with time. Here, we present age constraints from U-series dating of 44 sulfide samples collected by manned submersible from between the Mothra Field in the south to Sasquatch in the north. Samples are dated using 226Ra/Ba ratios from hydrothermal barite that precipitates along with the sulfide minerals. Most samples have been collected from within or near the active vent fields. Fifteen samples from the Main Endeavour Field (MEF) show a spectrum of ages from present to 2,430 years old, indicating that this field has been continuously active for at least ~2,400 years. MEF appears to be oldest currently active field. This minimum value for the age of hydrothermal activity also provides a minimum age of the axial valley itself. Ages from thirteen samples from the High-Rise Field indicate continuous venting for at least the past ~1,250 years. These age data are used in conjunction with age constraints of the volcanic flows to develop an integrated volcanic, hydrothermal and tectonic history of the Endeavour Segment. The total volume of hydrothermal sulfide within the axial valley, determined from high-resolution bathymetry, is used in conjunction with the age constraints of the sulfide material to determine the mass accumulation rates of sulfide along the Endeavour Segment. These data can be used to calibrate the efficiency of sulfide deposition from the hydrothermal vents, and provide a time-integrated history of heat, fluid and chemical fluxes at the ridge-segment scale. The comparison of time-integrated rates with

  4. Overexpression of activin-A and -B in malignant mesothelioma – Attenuated Smad3 signaling responses and ERK activation promote cell migration and invasive growth

    SciTech Connect

    Tamminen, Jenni A.; Yin, Miao; Rönty, Mikko; Sutinen, Eva; Pasternack, Arja; Ritvos, Olli; Myllärniemi, Marjukka; Koli, Katri

    2015-03-01

    Activin-A and activin-B, members of the TGF-β superfamily, are regulators of reproductive functions, inflammation and wound healing. These dimeric molecules regulate various cellular activities such as proliferation, migration and suvival. Malignant mesothelioma is an asbestos exposure related tumor affecting mainly pleura and it usually has a dismal prognosis. Here, we demonstrate that both activin-A and -B are abundantly expressed in mesothelioma tumor tissue as well as in cultured primary and established mesothelioma cells. Migratory and invasive mesothelioma cells were also found to have attenuated activation of the Smad2/3 pathway in response to activins. Migration and invasive growth of the cells in three-dimentional matrix was prevented by inhibition of activin activity using a soluble activin receptor 2B (sActR2B-Fc). This was associated with decreased ERK activity. Furthermore, migration and invasive growth was significantly inhibited by blocking ERK phosphorylation. Mesothelioma tumors are locally invasive and our results clearly suggest that acivins have a tumor-promoting function in mesothelioma through increasing expression and switching from canonical Smad3 pathway to non-canonical ERK pathway signaling. Blocking activin activity offers a new therapeutic approach for inhibition of mesothelioma invasive growth. - Highlights: • Activin-A and activin-B are highly expressed in mesothelioma. • Mesothelioma cell migration and invasive growth can be blocked with sActR2B. • Activin induced Smad3 activity is attenuated in invasive mesothelioma cells. • Activins induce ERK activity in mesothelioma cells.

  5. Sinomenine influences capacity for invasion and migration in activated human monocytic THP-1 cells by inhibiting the expression of MMP-2, MMP-9, and CD147

    PubMed Central

    Ou, Yang-qiong; Chen, Li-hua; Li, Xue-jun; Lin, Zhi-bin; Li, Wei-dong

    2009-01-01

    Aim: The aim of this study was to investigate the mechanism of the effects of Sinomenine (SIN) on the invasion and migration ability of activated human monocytic THP-1 cells (A-THP-1). Sinomenine is a pure alkaloid extracted from the Chinese medical plant Sinomenium acutum. Methods: Human monocytic THP-1 cells were induced to differentiate into macrophages with phorbol 12-myristate 13-acetate (PMA). Cells were treated with different concentrations of SIN. The invasion and migration ability of cells was tested by in vitro transwell assays. The levels of CD147 and MMPs were evaluated by flow cytometric analysis and zymographic analysis, respectively. The mRNA expression of CD147, MMP-2, and MMP-9 was measured by RT-PCR. Results: The invasion and migration ability of A-THP-1 cells was significantly inhibited by SIN in a concentration-dependent fashion; at the same time, the levels of CD147, MMP-2, and MMP-9 were markedly down-regulated. This inhibitory effect was most notable at concentrations of 0.25 mmol/L and 1.00 mmol/L (P<0.01). Conclusion: A possible mechanism of the inhibitory effect of SIN on cell invasion and migration ability is repression of the expression of MMP-2 and MMP-9, which strongly correlates with the inhibition of CD147 activity. PMID:19305422

  6. Persimmon peel extract attenuates PDGF-BB-induced human aortic smooth muscle cell migration and invasion through inhibition of c-Src activity.

    PubMed

    Son, Joe Eun; Hwang, Mun Kyung; Lee, Eunjung; Seo, Sang Gwon; Kim, Jong-Eun; Jung, Sung Keun; Kim, Jong Rhan; Ahn, Gwang-Hwan; Lee, Ki Won; Lee, Hyong Joo

    2013-12-15

    The unregulated migration and invasion of human aortic smooth muscle cells (HASMCs) into the intima is a crucial step in the development of atherosclerosis. Recently, the oriental persimmon extract (Diospyros kaki Thunb. cv. Fuyu) has been investigated for its anti-atherogenic properties, but the molecular mechanisms involved remain unclear. We investigated the inhibitory effects of persimmon peel and flesh extract on the platelet-derived growth factor (PDGF) BB-induced MMP-1 expression using Western blot, and abnormal migration and invasion of HASMCs using a modified Boyden chamber assay and a wound healing assay. We also evaluated the inhibitory effects of persimmon peel extract on aortic vessel thickening using a rat aortic sprouting assay. Persimmon peel (PPE), but not flesh extract (PFE), inhibited PDGF-BB-induced MMP-1 expression, cell migration and invasion in HASMCs, while suppressing the rat aortic sprouting. Western blot and in vitro kinase assay data demonstrated that PPE inhibited Src kinase activity and subsequently attenuated PDGF-BB-induced phosphorylation of MAPK and Akt signalling pathways. Taken together, our results indicate that persimmon peel might possess a potential anti-atherogenic effect through attenuation of ASMCs migration and invasion and aortic sprouting by direct inhibition of the c-Src kinase activity.

  7. Hydrology/Radionuclide Migration Program and related research activities; FY 1986 progress report, October 1, 1985--September 30, 1986

    SciTech Connect

    Jones, M.A.

    1992-02-01

    This report presents the results of technical studies conducted under the Hydrology/Radionuclide Migration Program (HRMP) at the Nevada Test Site (NTS) for the period of October 1, 1985 through September 30, 1986. The HRMP was initiated in 1973 as the Radionuclide Migration Program to study and better understand the hydrologic systems of the NTS and potential movement and rates of movement of radionuclides and other contaminants injected into these systems by underground nuclear testing.

  8. Oleanolic acid induces migration in Mv1Lu and MDA-MB-231 epithelial cells involving EGF receptor and MAP kinases activation

    PubMed Central

    Ruzafa-Martínez, María; Ramos-Morcillo, Antonio Jesús

    2017-01-01

    During wound healing, skin function is restored by the action of several cell types that undergo differentiation, migration, proliferation and/or apoptosis. These dynamics are tightly regulated by the evolution of the extra cellular matrix (ECM) contents along the process. Pharmacologically active flavonoids have shown to exhibit useful physiological properties interesting in pathological states. Among them, oleanolic acid (OA), a pentacyclic triterpene, shows promising properties over wound healing, as increased cell migration in vitro and improved wound resolution in vivo. In this paper, we pursued to disclose the molecular mechanisms underlying those effects, by using an in vitro scratch assay in two epithelial cell lines of different linage: non-malignant mink lung epithelial cells, Mv1Lu; and human breast cancer cells, MDA-MB-231. In every case, we observed that OA clearly enhanced cell migration for in vitro scratch closure. This correlated with the stimulation of molecular pathways related to mitogen-activated protein (MAP) kinases, as ERK1,2 and Jun N-terminal kinase (JNK) 1,2 activation and c-Jun phosphorylation. Moreover, MDA-MB-231 cells treated with OA displayed an altered gene expression profile affecting transcription factor genes (c-JUN) as well as proteins involved in migration and ECM dynamics (PAI1), in line with the development of an epithelial to mesenchymal transition (EMT) status. Strikingly, upon OA treatment, we observed changes in the epidermal growth factor receptor (EGFR) subcellular localization, while interfering with its signalling completely prevented migration effects. This data provides a physiological framework supporting the notion that lipophilic plant extracts used in traditional medicine, might modulate wound healing processes in vivo through its OA contents. The molecular implications of these observations are discussed. PMID:28231262

  9. Oleanolic acid induces migration in Mv1Lu and MDA-MB-231 epithelial cells involving EGF receptor and MAP kinases activation.

    PubMed

    Bernabé-García, Ángel; Armero-Barranco, David; Liarte, Sergio; Ruzafa-Martínez, María; Ramos-Morcillo, Antonio Jesús; Nicolás, Francisco José

    2017-01-01

    During wound healing, skin function is restored by the action of several cell types that undergo differentiation, migration, proliferation and/or apoptosis. These dynamics are tightly regulated by the evolution of the extra cellular matrix (ECM) contents along the process. Pharmacologically active flavonoids have shown to exhibit useful physiological properties interesting in pathological states. Among them, oleanolic acid (OA), a pentacyclic triterpene, shows promising properties over wound healing, as increased cell migration in vitro and improved wound resolution in vivo. In this paper, we pursued to disclose the molecular mechanisms underlying those effects, by using an in vitro scratch assay in two epithelial cell lines of different linage: non-malignant mink lung epithelial cells, Mv1Lu; and human breast cancer cells, MDA-MB-231. In every case, we observed that OA clearly enhanced cell migration for in vitro scratch closure. This correlated with the stimulation of molecular pathways related to mitogen-activated protein (MAP) kinases, as ERK1,2 and Jun N-terminal kinase (JNK) 1,2 activation and c-Jun phosphorylation. Moreover, MDA-MB-231 cells treated with OA displayed an altered gene expression profile affecting transcription factor genes (c-JUN) as well as proteins involved in migration and ECM dynamics (PAI1), in line with the development of an epithelial to mesenchymal transition (EMT) status. Strikingly, upon OA treatment, we observed changes in the epidermal growth factor receptor (EGFR) subcellular localization, while interfering with its signalling completely prevented migration effects. This data provides a physiological framework supporting the notion that lipophilic plant extracts used in traditional medicine, might modulate wound healing processes in vivo through its OA contents. The molecular implications of these observations are discussed.

  10. Astrocytes in Migration.

    PubMed

    Zhan, Jiang Shan; Gao, Kai; Chai, Rui Chao; Jia, Xi Hua; Luo, Dao Peng; Ge, Guo; Jiang, Yu Wu; Fung, Yin-Wan Wendy; Li, Lina; Yu, Albert Cheung Hoi

    2017-01-01

    Cell migration is a fundamental phenomenon that underlies tissue morphogenesis, wound healing, immune response, and cancer metastasis. Great progresses have been made in research methodologies, with cell migration identified as a highly orchestrated process. Brain is considered the most complex organ in the human body, containing many types of neural cells with astrocytes playing crucial roles in monitoring normal functions of the central nervous system. Astrocytes are mostly quiescent under normal physiological conditions in the adult brain but become migratory after injury. Under most known pathological conditions in the brain, spinal cord and retina, astrocytes are activated and become hypertrophic, hyperplastic, and up-regulating GFAP based on the grades of severity. These three observations are the hallmark in glia scar formation-astrogliosis. The reactivation process is initiated with structural changes involving cell process migration and ended with cell migration. Detailed mechanisms in astrocyte migration have not been studied extensively and remain largely unknown. Here, we therefore attempt to review the mechanisms in migration of astrocytes.

  11. Exogenous hydrogen sulfide exerts proliferation, anti-apoptosis, angiopoiesis and migration effects via activating HSP90 pathway in EC109 cells.

    PubMed

    Lei, Yiyan; Zhen, Yulan; Zhang, Wei; Sun, Xiuting; Lin, Xiaoxiong; Feng, Jianqiang; Luo, Honghe; Chen, Zhenguang; Su, Chunhua; Zeng, Bo; Chen, Jingfu

    2016-06-01

    Hydrogen sulfide (H2S) participates in diverse physiological and pathophysiologic processes of cancer both in vitro and in vivo. We have previously reported the proliferation/anti-apoptosis/angiogenesis/migration effects of exogenous H2S on liver cancer and glioma via amplifying the activation of NF-κB and p38 MAPK/ERK1/2-COX-2 pathway. However, the effects of H2S on EC109 esophageal cells remain unclear. The present study demonstrated the effects of exogenous H2S on cancer cell growth via activating HSP90 pathways in EC109 esophageal cells. EC109 esophageal cells were treated with 400 µmol/l NaHS (a donor of H2S) for 24 h. The expression levels of HSP90, bcl-2, caspase-3, bax and MMP-2 were detected by western blot assay. Cell viability was detected by Cell Counting Kit-8 (CCK-8). The migration rate was analyzed using a Transwell migration assay and ImageJ software. NaHS promoted cell proliferation, as evidenced by an increase in cell viability. In addition, NaHS treatment reduced apoptosis, as indicated by the increased bcl-2 expression and decreased cleaved caspase-3 and bax expression. Importantly, exposure of NaHS increased the expression of MMP-2, the migration rate and expression of VEGF. Notably, co-treatment of EC109 cells with NaHS and GA (an inhibitor of HSP90 pathway) largely suppressed the aforementioned NaHS-induced effects. The findings of the present study provided novel evidence that HSP90 pathway was involved in NaHS-induced cancer cell proliferation, anti-apoptosis, angiopoiesis and migration in EC109 esophageal cells.

  12. Metformin inhibits aldosterone-induced cardiac fibroblast activation, migration and proliferation in vitro, and reverses aldosterone+salt-induced cardiac fibrosis in vivo.

    PubMed

    Mummidi, Srinivas; Das, Nitin A; Carpenter, Andrea J; Kandikattu, Hemanthkumar; Krenz, Maike; Siebenlist, Ulrich; Valente, Anthony J; Chandrasekar, Bysani

    2016-09-01

    The overall goals of this study were to investigate whether metformin exerts anti-fibrotic effects in aldosterone (Aldo)+salt-treated wild type mouse hearts, and determine the underlying molecular mechanisms in isolated adult cardiac fibroblasts (CF). In vitro, Aldo induced CF activation, migration, and proliferation, and these effects were inhibited by metformin. Further, Aldo induced PPM1A (Protein Phosphatase Magnesium Dependent 1A) activation and inhibited AMPK phosphorylation. At a pharmacologically relevant concentration, metformin restored AMPK activation, and inhibited Aldo-induced Nox4/H2O2-dependent TRAF3IP2 induction, pro-inflammatory cytokine expression, and CF migration and proliferation. Further, metformin potentiated the inhibitory effects of spironolactone, a mineralocorticoid receptor antagonist, on Aldo-induced collagen expression, and CF migration and proliferation. These results were recapitulated in vivo, where metformin reversed Aldo+salt-induced oxidative stress, suppression of AMPK activation, TRAF3IP2 induction, pro-inflammatory cytokine expression, and cardiac fibrosis, without significantly modulating systolic blood pressure. These in vitro and in vivo data indicate that metformin has the potential to reduce adverse cardiac remodeling in hypertensive heart disease.

  13. The sGC activator inhibits the proliferation and migration, promotes the apoptosis of human pulmonary arterial smooth muscle cells via the up regulation of plasminogen activator inhibitor-2

    SciTech Connect

    Zhang, Shuai; Zou, Lihui; Yang, Ting; Yang, Yuanhua; Zhai, Zhenguo; Xiao, Fei; Wang, Chen

    2015-03-15

    Background: Different types of pulmonary hypertension (PH) share the same process of pulmonary vascular remodeling, the molecular mechanism of which is not entirely clarified by far. The abnormal biological behaviors of pulmonary arterial smooth muscle cells (PASMCs) play an important role in this process. Objectives: We investigated the regulation of plasminogen activator inhibitor-2 (PAI-2) by the sGC activator, and explored the effect of PAI-2 on PASMCs proliferation, apoptosis and migration. Methods: After the transfection with PAI-2 overexpression vector and specific siRNAs or treatment with BAY 41-2272 (an activator of sGC), the mRNA and protein levels of PAI-2 in cultured human PASMCs were detected, and the proliferation, apoptosis and migration of PASMCs were investigated. Results: BAY 41-2272 up regulated the endogenous PAI-2 in PASMCs, on the mRNA and protein level. In PAI-2 overexpression group, the proliferation and migration of PASMCs were inhibited significantly, and the apoptosis of PASMCs was increased. In contrast, PAI-2 knockdown with siRNA increased PASMCs proliferation and migration, inhibited the apoptosis. Conclusions: PAI-2 overexpression inhibits the proliferation and migration and promotes the apoptosis of human PASMCs. Therefore, sGC activator might alleviate or reverse vascular remodeling in PH through the up-regulation of PAI-2. - Highlights: • sGC activator BAY41-2272 up regulated PAI-2 in PASMCs, on the mRNA and protein level. • PAI-2 overexpression inhibits the proliferation and migration of human PASMCs. • PAI-2 overexpression promotes the apoptosis of human PASMCs. • sGC activator might alleviate the vascular remodeling in pulmonary hypertension.

  14. The Sal-like 4 - integrin α6β1 network promotes cell migration for metastasis via activation of focal adhesion dynamics in basal-like breast cancer cells.

    PubMed

    Itou, Junji; Tanaka, Sunao; Li, Wenzhao; Iida, Atsuo; Sehara-Fujisawa, Atsuko; Sato, Fumiaki; Toi, Masakazu

    2017-01-01

    During metastasis, cancer cell migration is enhanced. However, the mechanisms underlying this process remain elusive. Here, we addressed this issue by functionally analyzing the transcription factor Sal-like 4 (SALL4) in basal-like breast cancer cells. Loss-of-function studies of SALL4 showed that this transcription factor is required for the spindle-shaped morphology and the enhanced migration of cancer cells. SALL4 also up-regulated integrin gene expression. The impaired cell migration observed in SALL4 knockdown cells was restored by overexpression of integrin α6 and β1. In addition, we clarified that integrin α6 and β1 formed a heterodimer. At the molecular level, loss of the SALL4 - integrin α6β1 network lost focal adhesion dynamics, which impairs cell migration. Over-activation of Rho is known to inhibit focal adhesion dynamics. We observed that SALL4 knockdown cells exhibited over-activation of Rho. Aberrant Rho activation was suppressed by integrin α6β1 expression, and pharmacological inhibition of Rho activity restored cell migration in SALL4 knockdown cells. These results indicated that the SALL4 - integrin α6β1 network promotes cell migration via modulation of Rho activity. Moreover, our zebrafish metastasis assays demonstrated that this gene network enhances cell migration in vivo. Our findings identify a potential new therapeutic target for the prevention of metastasis, and provide an improved understanding of cancer cell migration.

  15. Migration Theories

    NASA Astrophysics Data System (ADS)

    Crida, Aurélien

    2015-08-01

    The great variety of the architectures of the extra-solar planetary systems has revealed the fundamental role played by planetary migration: the interactions between the planets and the gaseous disk in which they form leads to a modification of their orbits. Here, I will review the basic processes and the most recent results in this area.Planets up to ~50 Earth masses are prone to so-called type I migration.I will describe the processes at play, namely the Lindblad and corotation torques, and explain how the total torque depends on the planet mass and the local disk structure. Application to realistic disks shows one or two sweet spot(s) for outward migration of planets roughly between 5 and 30 Earth masses around the snowline ; this is confirmed by dedicated 3D numerical simulations. This has strong consequences on the formation of hot Super-Earths or mini-Neptunes.For smaller mass planets, it has been recently proposed that the heating of the neighboring gas by the luminous planet can lead to a positive torque, hence promoting outward migration. On the other hand, if the planet is not a heat source, a cold finger appears, whose resulting torque is negative. Applications of these two recent results should be discussed.Giant planets open gaps in the proto-planetary disk, and then are supposedly subject to type II migration, following the viscous accretion of the disk. This standard picture has been questioned recently, as gas appears to drift through the gap. Although the gap opening process is well understood in 2D for a planet on a fixed orbit, recent results on 3D simulations or migrating planets make the picture more accurate.Our ever better understanding of planet-disk interactions is of crucial importance as the statistics on extra solar systems keep growing and the results of these interactions are now imaged.

  16. Migrating Planets

    NASA Astrophysics Data System (ADS)

    Murray, N.; Hansen, B.; Holman, M.; Tremaine, S.

    1998-01-01

    A planet orbiting in a disk of planetesimals can experience an instability in which it migrates to smaller orbital radii. Resonant interactions between the planet and planetesimals remove angular momentum from the planetesimals, increasing their eccentricities. Subsequently, the planetesimals either collide with or are ejected by the planet, reducing the semimajor axis of the planet. If the surface density of planetesimals exceeds a critical value, corresponding to 0.03 solar masses of gas inside the orbit of Jupiter, the planet will migrate inward a large distance. This instability may explain the presence of Jupiter-mass objects in small orbits around nearby stars.

  17. Initiation of Oligodendrocyte Progenitor Cell Migration by a PDGF-A Activated Extracellular Regulated Kinase (ERK) Signaling Pathway

    PubMed Central

    Frost, Emma E.; Zhou, ZhiCheng; Krasnesky, Kimberley; Armstrong, Regina C.

    2009-01-01

    During CNS development, oligodendrocyte progenitor (OP) cells migrate from germinal zones to presumptive white matter tracts to generate myelinating oligodendrocytes. In vitro and in vivo studies indicate that platelet-derived growth factor-A (PDGF-A) is a potent chemoattractant for OP cells and important for normal distribution throughout the developing CNS. However, PDGF-A does not localize in concentration gradients corresponding to OP migratory pathways, as would be expected for a chemoattractant to direct migration. Therefore, the mechanism by which PDGF-A regulates OP distribution remains to be clarified. Here we show that PDGF-A induces OP migration and continuous exposure to PDGF-A is not required to maintain migration. Using pharmacological inhibitors, we show that a self-sustaining extracellular-regulated-kinase signaling pathway drives OP migration for up to 72 hours after the initial PDGF stimulus. These findings indicate PDGF-A may act to mobilize OP cells that then respond to distinct directional signals to distribute appropriately within the CNS. PMID:18512152

  18. Determination of the activation enthalpy for migration of dislocations in plastically deformed 8006 Al-alloy by positron annihilation lifetime technique

    NASA Astrophysics Data System (ADS)

    Salah, Mohammed; Abdel-Rahman, M.; Badawi, Emad A.; Abdel-Rahman, M. A.

    2016-06-01

    The activation enthalpy for migration of dislocations of plastically deformed 8006 Al-alloy was investigated by positron annihilation lifetime technique. Plastic deformation using a hydraulic press produces mainly dislocations and may produce point defects. The type of defect was studied by isochronal annealing which determines the temperature range of recovery of each type. Only one type of defect (dislocations) was observed for the investigated sample and was found to be recovered within the range 455-700 K. Isothermal annealing by slow cooling was performed through this range and used in determination of the activation enthalpy of migration of dislocations which was found to be 0.26 ± 0.01 eV.

  19. Ca2+ signaling evoked by activation of Na+ channels and Na+/Ca2+ exchangers is required for GABA-induced NG2 cell migration

    PubMed Central

    Tong, Xiao-ping; Li, Xiang-yao; Zhou, Bing; Shen, Wanhua; Zhang, Zhi-jun; Xu, Tian-le

    2009-01-01

    NG2 cells originate from various brain regions and migrate to their destinations during early development. These cells express voltage-gated Na+ channels but fail to produce typical action potentials. The physiological role of Na+ channels in these cells is unclear. We found that GABA induces membrane depolarization and Ca2+ elevation in NG2 cells, a process requiring activation of GABAA receptors, Na+ channels, and Na+/Ca2+ exchangers (NCXs), but not Ca2+ channels. We have identified a persistent Na+ current in these cells that may underlie the GABA-induced pathway of prolonged Na+ elevation, which in turn triggers Ca2+ influx via NCXs. This unique Ca2+ signaling pathway is further shown to be involved in the migration of NG2 cells. Thus, GABAergic signaling mediated by sequential activation of GABAA receptors, noninactivating Na+ channels, and NCXs may play an important role in the development and function of NG2 glial cells in the brain. PMID:19596850

  20. Dateline Migration.

    ERIC Educational Resources Information Center

    Tomasi, Lydio E., Ed.

    1995-01-01

    Presents data on international migration and its effects in and between various countries in North America, Europe, and Africa. Discussions include refugee, immigrant, and migrant worker flows; the legal, political, and social problems surrounding immigrants; alien terrorism and law enforcement problems; and migrant effects on education, social…

  1. Oncogenic S1P signalling in EBV-associated nasopharyngeal carcinoma activates AKT and promotes cell migration through S1P receptor 3.

    PubMed

    Lee, Hui Min; Lo, Kwok-Wai; Wei, Wenbin; Tsao, Sai Wah; Chung, Grace Tin Yun; Ibrahim, Maha Hafez; Dawson, Christopher W; Murray, Paul G; Paterson, Ian C; Yap, Lee Fah

    2017-02-27

    Undifferentiated nasopharyngeal carcinoma (NPC) is a cancer with high metastatic potential that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the functional contribution of sphingosine-1-phosphate (S1P) signalling to the pathogenesis of NPC. We show that EBV infection or ectopic expression of the EBV-encoded latent genes (EBNA1, LMP1 and LMP2A) can up-regulate sphingosine kinase 1 (SPHK1), the key enzyme that produces S1P, in NPC cell lines. Exogenous addition of S1P promotes the migration of NPC cells through the activation of AKT; shRNA knockdown of SPHK1 resulted in a reduction in the levels of activated AKT and inhibition of cell migration. We also show that S1P receptor 3 (S1PR3) mRNA is over-expressed in EBV-positive NPC patient-derived xenografts and a subset of primary NPC tissues, and that knockdown of S1PR3 suppressed the activation of AKT and the S1P-induced migration of NPC cells. Taken together, our data point to a central role for EBV in mediating the oncogenic effects of S1P in NPC and identify S1P signalling as a potential therapeutic target in this disease.

  2. Luteolin exerts pro-apoptotic effect and anti-migration effects on A549 lung adenocarcinoma cells through the activation of MEK/ERK signaling pathway.

    PubMed

    Meng, Guanmin; Chai, Kequn; Li, Xinda; Zhu, Yongqiang; Huang, Weihua

    2016-09-25

    An increasing amount of evidence suggests that luteolin, a common dietary flavonoid that is widely distributed in plants and foods, has been shown to be protective against cancer. However, the precise underlying mechanisms of its action against lung cancer are still poorly understood. In the present study, we investigated whether luteolin exhibits the anti-cancer effect in lung cancer through the induction of cell apoptosis and inhibition of cell migration, and whether mitogen-activated protein kinases (MAPKs) and Akt signaling pathways are required. Results revealed that luteolin exerted an anti-proliferation effect in a dose- and time-dependent manner in A549 lung adenocarcinoma cells, and induced apoptosis with a concomitant increase in the activation of caspases-3 and -9, diminution of Bcl-2, elevation in Bax expression, and the phosphorylation of MEK and its down-stream kinase ERK, as well as the activation of Akt. Luteolin also dramatically inhibited cell motility and migration in A549 cells. The inhibitor of MEK-ERK pathway protected against luteolin-induced cell death and suppressed the apoptosis-inducing and anti-migratory effects of luteolin, suggesting MEK-ERK signaling pathway plays an important role in mediating the pro-apoptotic effect and anti-migration effects of luteolin. Taken together, this study provides a new insight into the mode of action of luteolin on lung cancer.

  3. GRANULOCYTE COLONY-STIMULATING FACTOR (G-CSF) UPREGULATES β1 INTEGRIN AND INCREASES MIGRATION OF HUMAN TROPHOBLAST SWAN 71 CELLS VIA PI3K AND MAPK ACTIVATION

    PubMed Central

    Furmento, Verónica A.; Marino, Julieta; Blank, Viviana C.; Cayrol, María Florencia; Cremaschi, Graciela A.; Aguilar, Rubén C.; Roguin, Leonor P.

    2017-01-01

    Multiple cytokines and growth factors expressed at the fetal-maternal interface are involved in the regulation of trophoblast functions and placental growth, but the role of G-CSF has not been completely established. Based on our previous study showing that G-CSF increases the activity of matrix metalloproteinase-2 and the release of vascular endothelial growth factor in Swan 71 human trophoblast cells, in this work we explore the possible contribution of G-CSF to cell migration and the G-CSF-triggered signaling pathway. We found that G-CSF induced morphological changes on actin cytoskeleton consistent with a migratory cell phenotype. G-CSF also up-regulated the expression levels of β1 integrin and promoted Swan 71 cell migration. By using selective pharmacological inhibitors and dominant negative mutants we showed that PI3K, Erk 1/2 and p38 pathways are required for promoting Swan 71 cell motility. It was also demonstrated that PI3K behaved as an upstream regulator of Erk 1/2 and p38 MAPK. In addition, the increase of β1 integrin expression was dependent on PI3K activation. In conclusion, our results indicate that G-CSF stimulates β1 integrin expression and Swan 71 cell migration by activating PI3K and MAPK signaling pathways, suggesting that G-CSF should be considered as an additional regulatory factor that contributes to a successful embryo implantation and to the placenta development. PMID:26992288

  4. Granulocyte colony-stimulating factor (G-CSF) upregulates β1 integrin and increases migration of human trophoblast Swan 71 cells via PI3K and MAPK activation.

    PubMed

    Furmento, Verónica A; Marino, Julieta; Blank, Viviana C; Cayrol, María Florencia; Cremaschi, Graciela A; Aguilar, Rubén C; Roguin, Leonor P

    2016-03-15

    Multiple cytokines and growth factors expressed at the fetal-maternal interface are involved in the regulation of trophoblast functions and placental growth, but the role of G-CSF has not been completely established. Based on our previous study showing that G-CSF increases the activity of matrix metalloproteinase-2 and the release of vascular endothelial growth factor in Swan 71 human trophoblast cells, in this work we explore the possible contribution of G-CSF to cell migration and the G-CSF-triggered signaling pathway. We found that G-CSF induced morphological changes on actin cytoskeleton consistent with a migratory cell phenotype. G-CSF also up-regulated the expression levels of β1 integrin and promoted Swan 71 cell migration. By using selective pharmacological inhibitors and dominant negative mutants we showed that PI3K, Erk 1/2 and p38 pathways are required for promoting Swan 71 cell motility. It was also demonstrated that PI3K behaved as an upstream regulator of Erk 1/2 and p38 MAPK. In addition, the increase of β1 integrin expression was dependent on PI3K activation. In conclusion, our results indicate that G-CSF stimulates β1 integrin expression and Swan 71 cell migration by activating PI3K and MAPK signaling pathways, suggesting that G-CSF should be considered as an additional regulatory factor that contributes to a successful embryo implantation and to the placenta development.

  5. Morusin inhibits human cervical cancer stem cell growth and migration through attenuation of NF-κB activity and apoptosis induction.

    PubMed

    Wang, Li; Guo, Huijie; Yang, Liuqi; Dong, Lihua; Lin, Caiyu; Zhang, Jie; Lin, Ping; Wang, Xiujie

    2013-07-01

    Cancer stem cells (CSCs) are believed to be responsible for tumor metastasis, recurrence, and high mortality of cancer patients due to their high tumorigenicity resistance to chemo-radiotherapy. Morusin possesses anti-cancer activity through attenuation of NF-κB activity, which is up-regulated in cancer stem cells. The purpose of this study is to confirm the growth and migration inhibition effect of morusin on human cervical CSCs, and to clarify its partial mechanism of activity. Human cervical CSCs were enriched using non-adhesive culture system. Their stemness characteristics were identified with tumor sphere formation, self-renewal, toluidine blue staining, migration assays, RT-PCR analysis, and immunofluorescence staining of putative stem cell markers, Oct4, SOX2, and ALDH1; the epithelial-to-mesenchymal (EMT) transition markers and relevant transcription factors were evaluated with Western blotting. The growth and migration inhibition effects of morusin on human cervical CSCs were tested by cell proliferation, tumor sphere formation, and transwell assay; apoptotic death of human cervical CSCs in response to morusin was measured with DAPI staining, apoptotic DNA fragmentation; NF-κBp65, Bcl-2, Bax, and caspase-3 protein expressions were detected through Western blotting. Under this non-adhesive culture system, typical tumor spheres appeared within 5-7 days, the tumor sphere formation, self-renewal, and cell migration, expressions of putative stem cell markers, EMT markers, and relevant transcription factors of the tumor sphere cells were increased significantly. After morusin treatment, the proliferation, tumor sphere formation, and migration of human cervical CSCs were decreased significantly, DAPI-stained apoptotic cells increased, apoptotic DNA fragmentations formed evidently; the expression levels of NF-κBp65 and Bcl-2 decreased significantly, Bax, and caspase-3 increased significantly in a dose-dependent manner. Using the non-adhesive culture system

  6. TGF-β effects on prostate cancer cell migration and invasion are mediated by PGE2 through activation of PI3K/AKT/mTOR pathway.

    PubMed

    Vo, Baohan T; Morton, Derrick; Komaragiri, Shravan; Millena, Ana C; Leath, Chelesie; Khan, Shafiq A

    2013-05-01

    TGF-β plays an important role in the progression of prostate cancer. It exhibits both tumor suppressor and tumor-promoting activities. Correlations between cyclooxygenase (COX)-2 overexpression and enhanced production of prostaglandin (PG)E2 have been implicated in cancer progression; however, there are no studies indicating that TGF-β effects in prostate cancer cells involve PGE2 synthesis. In this study, we investigated TGF-β regulation of COX-1 and COX-2 expression in prostate cancer cells and whether the effects of TGF-β on cell proliferation and migration are mediated by PGE2. COX-1 protein was ubiquitously expressed in prostate cells; however, COX-2 protein levels were detected only in prostate cancer cells. TGF-β treatment increased COX-2 protein levels and PGE2 secretion in PC3 cells. Exogenous PGE2 and PGF2α had no effects on cell proliferation in LNCaP, DU145, and PC3 cells whereas PGE2 and TGF-β induced migration and invasive behavior in PC3 cells. Only EP2 and EP4 receptors were detected at mRNA levels in prostate cells. The EP4-targeting small interfering RNA inhibited PGE2 and TGF-β-induced migration of PC3 cells. TGF-β and PGE2 induce activation of PI3K/AKT/mammalian target of rapamycin pathway as indicated by increased AKT, p70S6K, and S6 phosphorylation. Rapamycin completely blocked the effects of TGF-β and PGE2 on phosphorylation of p70S6K and S6 but not on AKT phosphorylation. PGE2 and TGF-β induced phosphorylation of AKT, which was blocked by antagonists of PGE2 (EP4) receptors (L161982, AH23848) and PI3K inhibitor (LY294002) in PC3 cells. Pretreatment with L161982 or AH23848 blocked the stimulatory effects of PGE2 and TGF-β on cell migration, whereas LY294002 or rapamycin completely eliminated PGE2, TGF-β, and epidermal growth factor-induced migration in PC3 cells. We conclude that TGF-β increases COX-2 levels and PGE2 secretion in prostate cancer cells which, in turn, mediate TGF-β effects on cell migration and invasion through

  7. MiR-221 and miR-26b Regulate Chemotactic Migration of MSCs Toward HGF Through Activation of Akt and FAK.

    PubMed

    Zhu, Aisi; Kang, Naixin; He, Lihong; Li, Xianyang; Xu, Xiaojing; Zhang, Huanxiang

    2016-06-01

    The chemotactic migration of mesenchymal stem cells (MSCs) is fundamental for their use in cell-based therapies, but little is known about the molecular mechanisms that regulate their directed migration. MicroRNAs (miRNAs) participate in the regulation of a large variety of cellular processes. However, their roles in regulating the responses of MSCs to hepatocyte growth factor (HGF) remain elusive. Here, we found that microRNA-221 (miR-221) and microRNA-26b (miR-26b) were upregulated in MSCs subjected to HGF. Overexpression of miR-221 or miR-26b enhanced MSC migration through activation of PI3K/Akt signaling. Phosphatase and tensin homolog deleted on chromosome ten (PTEN) was identified as a potential target of miR-221 and miR-26b; overexpression of miR-221 or miR-26b decreased PTEN expression at both mRNA and protein levels. Overexpression of miR-221 or miR-26b in MSCs increased the phosphorylation of focal adhesion kinase (FAK), a downstream effector of PTEN, which regulates cell migration through assembly and distribution of focal adhesions (FAs), and more dot-like FAs were localized at the periphery of these cells. Altering miR-221 or miR-26b expression influenced the directed migration of MSCs toward HGF. Inhibition of miR-221 or miR-26b suppressed the phosphorylation of Akt and FAK and upregulated PTEN expression, which was partly restored by HGF treatment. Collectively, these results demonstrate that miR-221 and miR-26b participate in regulating the chemotactic response of MSCs toward HGF.

  8. Extracellular acidification synergizes with PDGF to stimulate migration of mouse embryo fibroblasts through activation of p38MAPK with a PTX-sensitive manner

    SciTech Connect

    An, Caiyan; Sato, Koichi; Wu, Taoya; Bao, Muqiri; Bao, Liang; Tobo, Masayuki; Damirin, Alatangaole

    2015-05-01

    The elucidation of the functional mechanisms of extracellular acidification stimulating intracellular signaling pathway is of great importance for developing new targets of treatment for solid tumors, and inflammatory disorders characterized by extracellular acidification. In the present study, we focus on the regulation of extracellular acidification on intracellular signaling pathways in mouse embryo fibroblasts (MEFs). We found extracellular acidification was at least partly involved in stimulating p38MAPK pathway through PTX-sensitive behavior to enhance cell migration in the presence or absence of platelet-derived growth factor (PDGF). Statistical analysis showed that the actions of extracellular acidic pH and PDGF on inducing enhancement of cell migration were not an additive effect. However, we also found extracellular acidic pH did inhibit the viability and proliferation of MEFs, suggesting that extracellular acidification stimulates cell migration probably through proton-sensing mechanisms within MEFs. Using OGR1-, GPR4-, and TDAG8-gene knock out technology, and real-time qPCR, we found known proton-sensing G protein-coupled receptors (GPCRs), transient receptor potential vanilloid subtype 1 (TRPV1), and acid-sensing ion channels (ASICs) were unlikely to be involved in the regulation of acidification on cell migration. In conclusion, our present study validates that extracellular acidification stimulates chemotactic migration of MEFs through activation of p38MAPK with a PTX-sensitive mechanism either by itself, or synergistically with PDGF, which was not regulated by the known proton-sensing GPCRs, TRPV1, or ASICs. Our results suggested that others proton-sensing GPCRs or ion channels might exist in MEFs, which mediates cell migration induced by extracellular acidification in the presence or absence of PDGF. - Highlights: • Acidic pH and PDGF synergize to stimulate MEFs migration via Gi/p38MAPK pathway. • Extracellular acidification inhibits the

  9. The androgen derivative 5alpha-androstane-3beta,17beta-diol inhibits prostate cancer cell migration through activation of the estrogen receptor beta subtype.

    PubMed

    Guerini, Vittoria; Sau, Daniela; Scaccianoce, Eugenia; Rusmini, Paola; Ciana, Paolo; Maggi, Adriana; Martini, Paolo G V; Katzenellenbogen, Benita S; Martini, Luciano; Motta, Marcella; Poletti, Angelo

    2005-06-15

    Prostate cancer growth depends, in its earlier stages, on androgens and is usually pharmacologically modulated with androgen blockade. However, androgen-ablation therapy may generate androgen-independent prostate cancer, often characterized by an increased invasiveness. We have found that the 5alpha-reduced testosterone derivative, dihydrotestosterone (the most potent natural androgen) inhibits cell migration with an androgen receptor-independent mechanism. We have shown that the dihydrotestosterone metabolite 5alpha-androstane-3beta,17beta-diol (3beta-Adiol), a steroid which does not bind androgen receptors, but efficiently binds the estrogen receptor beta (ERbeta), exerts a potent inhibition of prostate cancer cell migration through the activation of the ERbeta signaling. Very surprisingly, estradiol is not active, suggesting the existence of different pathways for ERbeta activation in prostate cancer cells. Moreover, 3beta-Adiol, through ERbeta, induces the expression of E-cadherin, a protein known to be capable of blocking metastasis formation in breast and prostate cancer cells. The inhibitory effects of 3beta-Adiol on prostate cancer cell migration is counteracted by short interfering RNA against E-cadherin. Altogether, the data showed that (a) circulating testosterone may act with estrogenic effects downstream in the catabolic process present in the prostate, and (b) that the estrogenic effect of testosterone derivatives (ERbeta-dependent) results in the inhibition of cell migration, although it is apparently different from that linked to estradiol on the same receptor and may be protective against prostate cancer invasion and metastasis. These results also shed some light on clinical observations suggesting that alterations in genes coding for 3beta-hydroxysteroid dehydrogenases (the enzymes responsible for 3beta-Adiol formation) are strongly correlated with hereditary prostate cancer.

  10. Integrin α4β1 controls G9a activity that regulates epigenetic changes and nuclear properties required for lymphocyte migration

    PubMed Central

    Zhang, Xiaohong; Cook, Peter C.; Zindy, Egor; Williams, Craig J.; Jowitt, Thomas A.; Streuli, Charles H.; MacDonald, Andrew S.; Redondo-Muñoz, Javier

    2016-01-01

    The mechanical properties of the cell nucleus change to allow cells to migrate, but how chromatin modifications contribute to nuclear deformability has not been defined. Here, we demonstrate that a major factor in this process involves epigenetic changes that underpin nuclear structure. We investigated the link between cell adhesion and epigenetic changes in T-cells, and demonstrate that T-cell adhesion to VCAM1 via α4β1 integrin drives histone H3 methylation (H3K9me2/3) through the methyltransferase G9a. In this process, active G9a is recruited to the nuclear envelope and interacts with lamin B1 during T-cell adhesion through α4β1 integrin. G9a activity not only reorganises the chromatin structure in T-cells, but also affects the stiffness and viscoelastic properties of the nucleus. Moreover, we further demonstrated that these epigenetic changes were linked to lymphocyte movement, as depletion or inhibition of G9a blocks T-cell migration in both 2D and 3D environments. Thus, our results identify a novel mechanism in T-cells by which α4β1 integrin signaling drives specific chromatin modifications, which alter the physical properties of the nucleus and thereby enable T-cell migration. PMID:26657637

  11. Human chorionic gonadotropin β induces migration and invasion via activating ERK1/2 and MMP-2 in human prostate cancer DU145 cells.

    PubMed

    Li, Zongwen; Li, Chunliu; Du, Lianlian; Zhou, Yan; Wu, Wei

    2013-01-01

    We previously demonstrated that human chorionic gonadotropin β (hCGβ) induced migration and invasion in human prostate cancer cells. However, the involved molecular mechanisms are unclear. Here, we established a stable prostate cancer cell line overexpressing hCGβ and tested hCGβ-triggered signaling pathways causing cell migration and invasion. ELISA showed that the hCGβ amount secreted into medium increased with culture time after the hCGβ-transfected cells were incubated for 3, 6, 9, 12 and 24 h. More, hCGβ standards promoted MAPK (ERK1/2) phosphorylation and increased MMP-2 expression and activity in both dose- and time-dependent manners in hCGβ non-transfected cells. In addition, hCGβ promoted ERK1/2 phosphorylation and increased MMP-2 expression and activity significantly in hCGβ transfected DU145 cells. Whereas ERK1/2 blocker PD98059 (25 µM) significantly downregulated phosphorylated ERK1/2 and MMP-2. Particularly, hCGβ promoted cell migration and invasion, yet the PD98059 diminished the hCGβ-induced cell motility under those conditions. These results indicated that hCGβ induced cell motility via promoting ERK1/2 phosphorylation and MMP-2 upregulation in human prostate cancer DU145 cells.

  12. Sema4D, the ligand for Plexin B1, suppresses c-Met activation and migration and promotes melanocyte survival and growth

    PubMed Central

    Soong, Joanne; Chen, Yulin; Shustef, Elina; Scott, Glynis

    2011-01-01

    Semaphorins are secreted and membrane bound proteins involved in neural pathfinding, organogenesis, and tumor progression, through Plexin and neuropilins receptors. We recently reported that Plexin B1, the Semaphorin 4D receptor, is a tumor suppressor protein for melanoma, in part, through inhibition of the oncogenic c-Met tyrosine kinase receptor. In this report we show that Sema4D is a protective paracrine factor for normal human melanocyte survival in response to ultraviolet irradiation, that it stimulates proliferation, and regulates the activity of the c-Met receptor. c-Met receptor signaling stimulates melanocyte migration, in part through down-regulation of the cell adhesion molecule E-cadherin. Sema4D suppressed activation of c-Met in response to its ligand hepatocyte growth factor (HGF), and partially blocked the suppressive effects of HGF on E-cadherin expression in melanocytes and HGF-dependent migration. These data demonstrate a role for Plexin B1 in maintenance of melanocyte survival and proliferation in the skin, and suggest that Semaphorin 4D and Plexin B1 act cooperatively with HGF and c-Met to regulate c-Met dependent effects in human melanocytes. Because our data show that Plexin B1 is profoundly down-regulated by UVB in melanocytes, loss of Plexin B1 may accentuate HGF dependent effects on melanocytes, including melanocyte migration. PMID:22189792

  13. Pasteurella multocida toxin (PMT) activates RhoGTPases, induces actin polymerization and inhibits migration of human dendritic cells, but does not influence macropinocytosis.

    PubMed

    Blöcker, Dagmar; Berod, Luciana; Fluhr, Joachim W; Orth, Joachim; Idzko, Marco; Aktories, Klaus; Norgauer, Johannes

    2006-03-01

    Dendritic cells (DCs) are considered as one of the principal initiators of immune responses. In their immature state, they migrate into peripheral tissue in order to uptake antigen and to patrol for danger signals. Upon maturation, they acquire the ability to migrate to the lymph nodes and present the captured antigens to T cells in order to direct the development of specific immune responses. There is evidence that microbial compounds interfere with proper functions of DCs in order to block innate and specific immunity. Here we characterized the influence of Pasteurella multocida toxin (PMT) on monocyte-derived DCs. Using pull-down assays with recombinant rhotekin or p21-activated kinase, we demonstrated the activation of RhoGTPases by PMT in DCs. Moreover, PMT induced changes in DC morphology and actin polymerization, impaired chemotaxin-induced actin re-organization and inhibited their migration response. However, macropinocytosis was not influenced by PMT. In summary, these data indicate that PMT inhibits proper function of the motility machinery in DCs, which might limit the development of adaptive immune surveillance during infection with Pasteurella multocida.

  14. Amplification loop of the inflammatory process is induced by P2X7R activation in intestinal epithelial cells in response to neutrophil transepithelial migration.

    PubMed

    Cesaro, Annabelle; Brest, Patrick; Hofman, Véronique; Hébuterne, Xavier; Wildman, Scott; Ferrua, Bernard; Marchetti, Sandrine; Doglio, Alain; Vouret-Craviari, Valérie; Galland, Franck; Naquet, Philippe; Mograbi, Baharia; Unwin, Robert; Hofman, Paul

    2010-07-01

    Inflammatory bowel diseases (IBD) are characterized during their active phase by polymorphonuclear leukocyte (PMNL) transepithelial migration. The efflux of PMNL into the mucosa is associated with the production of proinflammatory cytokines and the release of ATP from damaged and necrotic cells. The expression and function of purinergic P2X(7) receptor (P2X(7)R) in intestinal epithelial cells (IEC) and its potential role in the "cross talk" between IEC and PMNL have not been explored. The aims of the present study were 1) to examine P2X(7)R expression in IEC (T84 cells) and in human intestinal biopsies; 2) to detect any changes in P2X(7)R expression in T84 cells during PMNL transepithelial migration, and during the active and quiescent phases of IBD; and 3) to test whether P2X(7)R stimulation in T84 monolayers can induce caspase-1 activation and IL-1beta release by IEC. We found that a functional ATP-sensitive P2X(7)R is constitutively expressed at the apical surface of IEC T84 cells. PMNL transmigration regulates dynamically P2X(7)R expression and alters its distribution from the apical to basolateral surface of IEC during the early phase of PMNL transepithelial migration in vitro. P2X(7)R expression was weak in intestinal biopsies obtained during the active phase of IBD. We show that activation of epithelial P2X(7)R is mandatory for PMNL-induced caspase-1 activation and IL-1beta release by IEC. Overall, these changes in P2X(7)R function may serve to tailor the intensity of the inflammatory response and to prevent IL-1beta overproduction and inflammatory disease.

  15. A non-mitotic role for Aurora kinase A as a direct activator of cell migration upon interaction with PLD, FAK and Src.

    PubMed

    Mahankali, Madhu; Henkels, Karen M; Speranza, Francis; Gomez-Cambronero, Julian

    2015-02-01

    Timely activation of Aurora kinase A (AURA, also known as AURKA) is vital for centrosome formation and the progression of mitosis. Nonetheless, it is still unclear if and when other cellular functions are activated by AURA. We report here that Src phosphorylates and activates AURA at T288, and AURA also activates focal adhesion kinase (FAK, also known as PTK2), leading to initiation of cell movement. An additional and new way by which AURA is regulated, is by phospholipase D2 (PLD2), which causes AURA activation. In addition, AURA phosphorylates PLD, so both proteins engage in a positive reinforcement loop. AURA and PLD2 form a protein–protein complex and colocalize to cytoplasmic regions in cells. The reason why PLD activates AURA is because of the production of phosphatidic acid by the lipase, which binds directly to AURA, with the region E171–E211 projected to be a phosphatidic-acid-binding pocket. Furthermore, this direct interaction with phosphatidic acid enhances tubulin polymerization and cooperates synergistically with AURA, FAK and Src in yielding a fully effectual cellular migration. Thus, Src and FAK, and PLD and phosphatidic acid are new upstream regulators of AURA that mediate its role in the non-mitotic cellular function of cell migration.

  16. Roles of taurine-mediated tonic GABAA receptor activation in the radial migration of neurons in the fetal mouse cerebral cortex.

    PubMed

    Furukawa, Tomonori; Yamada, Junko; Akita, Tenpei; Matsushima, Yoshitaka; Yanagawa, Yuchio; Fukuda, Atsuo

    2014-01-01

    γ-Aminobutyric acid (GABA) depolarizes embryonic cerebrocortical neurons and continuous activation of the GABAA receptor (GABAAR) contributes to their tonic depolarization. Although multiple reports have demonstrated a role of GABAAR activation in neocortical development, including in migration, most of these studies have used pharmacological blockers. Herein, we performed in utero electroporation in GABA synthesis-lacking homozygous GAD67-GFP knock-in mice (GAD67(GFP/GFP)) to label neurons born in the ventricular zone. Three days after electroporation, there were no differences in the distribution of labeled cells between the genotypes. The dose-response properties of labeled cells to GABA were equivalent among genotypes. However, continuous blockade of GABAAR with the GABAAR antagonist SR95531 accelerated radial migration. This effect of GABAAR blockade in GAD67(GFP/GFP) mice suggested a role for alternative endogenous GABAAR agonists. Thus, we tested the role of taurine, which is derived from maternal blood but is abundant in the fetal brain. The taurine-evoked currents in labeled cells were mediated by GABAAR. Taurine uptake was blocked by a taurine transporter inhibitor, 2-(guanidino)ethanesulfonic acid (GES), and taurine release was blocked by a volume-sensitive anion channel blocker, 4-(2-butyl-6,7-dichlor-2-cyclopentylindan-1-on-5-yl) oxobutyric acid, as examined through high-performance liquid chromatography. GES increased the extracellular taurine concentration and induced an inward shift of the holding current, which was reversed by SR95531. In a taurine-deficient mouse model, the GABAAR-mediated tonic currents were greatly reduced, and radial migration was accelerated. As the tonic currents were equivalent among the genotypes of GAD67-GFP knock-in mice, taurine, rather than GABA, might play a major role as an endogenous agonist of embryonic tonic GABAAR conductance, regulating the radial migration of neurons in the developing neocortex.

  17. Roles of taurine-mediated tonic GABAA receptor activation in the radial migration of neurons in the fetal mouse cerebral cortex

    PubMed Central

    Furukawa, Tomonori; Yamada, Junko; Akita, Tenpei; Matsushima, Yoshitaka; Yanagawa, Yuchio; Fukuda, Atsuo

    2014-01-01

    γ-Aminobutyric acid (GABA) depolarizes embryonic cerebrocortical neurons and continuous activation of the GABAA receptor (GABAAR) contributes to their tonic depolarization. Although multiple reports have demonstrated a role of GABAAR activation in neocortical development, including in migration, most of these studies have used pharmacological blockers. Herein, we performed in utero electroporation in GABA synthesis-lacking homozygous GAD67-GFP knock-in mice (GAD67GFP/GFP) to label neurons born in the ventricular zone. Three days after electroporation, there were no differences in the distribution of labeled cells between the genotypes. The dose–response properties of labeled cells to GABA were equivalent among genotypes. However, continuous blockade of GABAAR with the GABAAR antagonist SR95531 accelerated radial migration. This effect of GABAAR blockade in GAD67GFP/GFP mice suggested a role for alternative endogenous GABAAR agonists. Thus, we tested the role of taurine, which is derived from maternal blood but is abundant in the fetal brain. The taurine-evoked currents in labeled cells were mediated by GABAAR. Taurine uptake was blocked by a taurine transporter inhibitor, 2-(guanidino)ethanesulfonic acid (GES), and taurine release was blocked by a volume-sensitive anion channel blocker, 4-(2-butyl-6,7-dichlor-2-cyclopentylindan-1-on-5-yl) oxobutyric acid, as examined through high-performance liquid chromatography. GES increased the extracellular taurine concentration and induced an inward shift of the holding current, which was reversed by SR95531. In a taurine-deficient mouse model, the GABAAR-mediated tonic currents were greatly reduced, and radial migration was accelerated. As the tonic currents were equivalent among the genotypes of GAD67-GFP knock-in mice, taurine, rather than GABA, might play a major role as an endogenous agonist of embryonic tonic GABAAR conductance, regulating the radial migration of neurons in the developing neocortex. PMID:24734001

  18. RLIP76 regulates Arf6-dependent cell spreading and migration by linking ARNO with activated R-Ras at recycling endosomes

    PubMed Central

    Wurtzel, Jeremy G.T.; Lee, Seunghyung; Singhal, Sharad S.; Awasthi, Sanjay; Ginsberg, Mark H.; Goldfinger, Lawrence E.

    2015-01-01

    R-Ras small GTPase enhances cell spreading and motility via RalBP1/RLIP76, an R-Ras effector that links GTP-R-Ras to activation of Arf6 and Rac1 GTPases. Here, we report that RLIP76 performs these functions by binding cytohesin-2/ARNO, an Arf GTPase guanine exchange factor, and connecting it to R-Ras at recycling endosomes. RLIP76 formed a complex with R-Ras and ARNO by binding ARNO via its N-terminus (residues 1-180) and R-Ras via residues 180-192. This complex was present in Rab11-positive recycling endosomes and the presence of ARNO in recycling endosomes required RLIP76, and was not supported by RLIP76(Δ1-180) or RLIP76(Δ180-192). Spreading and migration required RLIP76(1-180), and RLIP76(Δ1-180) blocked ARNO recruitment to recycling endosomes, and spreading. Arf6 activation with an ArfGAP inhibitor overcame the spreading defects in RLIP76-depleted cells or cells expressing RLIP76(Δ1-180). Similarly, RLIP76(Δ1-180) or RLIP76(Δ180-192) suppressed Arf6 activation. Together these results demonstrate that RLIP76 acts as a scaffold at recycling endosomes by binding activated R-Ras, recruiting ARNO to activate Arf6, thereby contributing to cell spreading and migration. PMID:26498519

  19. Soluble guanylyl cyclase-activated cyclic GMP-dependent protein kinase inhibits arterial smooth muscle cell migration independent of VASP-serine 239 phosphorylation.

    PubMed

    Holt, Andrew W; Martin, Danielle N; Shaver, Patti R; Adderley, Shaquria P; Stone, Joshua D; Joshi, Chintamani N; Francisco, Jake T; Lust, Robert M; Weidner, Douglas A; Shewchuk, Brian M; Tulis, David A

    2016-09-01

    Coronary artery disease (CAD) accounts for over half of all cardiovascular disease-related deaths. Uncontrolled arterial smooth muscle (ASM) cell migration is a major component of CAD pathogenesis and efforts aimed at attenuating its progression are clinically essential. Cyclic nucleotide signaling has long been studied for its growth-mitigating properties in the setting of CAD and other vascular disorders. Heme-containing soluble guanylyl cyclase (sGC) synthesizes cyclic guanosine monophosphate (cGMP) and maintains vascular homeostasis predominantly through cGMP-dependent protein kinase (PKG) signaling. Considering that reactive oxygen species (ROS) can interfere with appropriate sGC signaling by oxidizing the cyclase heme moiety and so are associated with several CVD pathologies, the current study was designed to test the hypothesis that heme-independent sGC activation by BAY 60-2770 (BAY60) maintains cGMP levels despite heme oxidation and inhibits ASM cell migration through phosphorylation of the PKG target and actin-binding vasodilator-stimulated phosphoprotein (VASP). First, using the heme oxidant ODQ, cGMP content was potentiated in the presence of BAY60. Using a rat model of arterial growth, BAY60 significantly reduced neointima formation and luminal narrowing compared to vehicle (VEH)-treated controls. In rat ASM cells BAY60 significantly attenuated cell migration, reduced G:F actin, and increased PKG activity and VASP Ser239 phosphorylation (pVASP·S239) compared to VEH controls. Site-directed mutagenesis was then used to generate overexpressing full-length wild type VASP (FL-VASP/WT), VASP Ser239 phosphorylation-mimetic (FL-VASP/239D) and VASP Ser239 phosphorylation-resistant (FL-VASP/239A) ASM cell mutants. Surprisingly, FL-VASP/239D negated the inhibitory effects of FL-VASP/WT and FL-VASP/239A cells on migration. Furthermore, when FL-VASP mutants were treated with BAY60, only the FL-VASP/239D group showed reduced migration compared to its VEH controls

  20. Effect of electro-activated brine solution on the migration of metallic ions from the cans to the product in sterilized canned sweet corn.

    PubMed

    Liato, Viacheslav; Labrie, Steve; Benali, Marzouk; Aider, Mohammed

    2016-11-01

    Tinplate cans were used to study if electro-activated brine solution (EAS) is more corrosive than conventional one by ICP analysis. The results showed different effects of EAS on cans, alone or filled with product. Acidic EAS (pH 2-3) and Redox +900 to +1200 mV highly reacted with the cans. The concentrations of Zn, Fe, and Cu in the solution were 0.028, 28.81, and 0.022 ppm, respectively. No Sn migration was observed in this case. When neutral or acidic chlorine-free EAS was used, no significant difference was observed in comparison with the corrosivity of standard NaCl brine. Alkaline EAS with pH>10 and negative E (≤-966 mV) did not affect Zn, Fe, and Cu migration. However, it affected tin migration. Nevertheless, it is important to mention that even if some corrosion was observed, it was in the limit of the permitted level of concentration when the cans were filled with a product.

  1. Conditioned media from human ovarian cancer endothelial progenitor cells induces ovarian cancer cell migration by activating epithelial-to-mesenchymal transition.

    PubMed

    Teng, L; Peng, S; Guo, H; Liang, H; Xu, Z; Su, Y; Gao, L

    2015-11-01

    Bone marrow-derived endothelial progenitor cells (EPCs) migrate to and engraft at ovarian cancer sites. Understanding the interactions between ovarian cancer cells and EPCs is fundamental for determining whether to harness EPC-tumor interactions for delivery of therapeutic agents or target them for intervention. Ovarian cancer cell lines (SKOV-3 and OVCAR-3) were cultured alone or in EPC-conditioned media (EPC-CM). Migration of ovarian cancer cells was detected by transwell chamber. N-cadherin and E-cadherin expression were analyzed by real-time reverse transcription PCR and western blot. EPC-CM can increase transforming growth factor-beta (TGF-β) secretion in SKOV-3 and OVCAR-3 cells. EPC-CM induced loss of ovarian cancer cell-cell junctions, downregulation of E-cadherin, upregulation of N-cadherin and acquisition of a fibroblastic phenotype, consistent with an epithelial-to-mesenchymal transition (EMT). The specific TGF-β inhibitor SB431542 abolished the SKOV-3 and OVCAR-3 ovarian cancer cell migration induced by EPC-CM. In SKOV-3 and OVCAR-3 cells, EPC-CM downregulated E-cadherin and concurrently upregulated N-cadherin. EPC-CM upregulated the expression of transcriptional repressors of E-cadherin, Snail and Twist. Treatment with SB431542 abolished the effects of EPC-CM on the relative expression levels of cadherin, Snail and Twist. This study demonstrates that TGF-β has a role in EPC-CM-induced ovarian cancer migration by activating EMT.

  2. Nerve growth factor enhances voltage-gated Na+ channel activity and Transwell migration in Mat-LyLu rat prostate cancer cell line.

    PubMed

    Brackenbury, William J; Djamgoz, Mustafa B A

    2007-03-01

    The highly dynamic nature of voltage-gated Na+ channel (VGSC) expression and its controlling mechanism(s) are not well understood. In this study, we investigated the possible involvement of nerve growth factor (NGF) in regulating VGSC activity in the strongly metastatic Mat-LyLu cell model of rat prostate cancer (PCa). NGF increased peak VGSC current density in a time- and dose-dependent manner. NGF also shifted voltage to peak and the half-activation voltage to more positive potentials, and produced currents with faster kinetics of activation; sensitivity to the VGSC blocker tetrodotoxin (TTX) was not affected. The NGF-induced increase in peak VGSC current density was suppressed by both the pan-trk antagonist K252a, and the protein kinase A (PKA) inhibitor KT5720. NGF did not affect the Nav1.7 mRNA level, but the total VGSC alpha-subunit protein level was upregulated. NGF potentiated the cells' migration in Transwell assays, and this was not affected by TTX. We concluded that NGF upregulated functional VGSC expression in Mat-LyLu cells, with PKA as a signaling intermediate, but enhancement of migration by NGF was independent of VGSC activity.

  3. The phosphatase of regenerating liver 3 (PRL-3) promotes cell migration through Arf-activity-dependent stimulation of integrin α5 recycling.

    PubMed

    Krndija, Denis; Münzberg, Christin; Maass, Ulrike; Hafner, Margit; Adler, Guido; Kestler, Hans A; Seufferlein, Thomas; Oswald, Franz; von Wichert, Götz

    2012-08-15

    The formation of metastasis is one of the most critical problems in oncology. The phosphatase of regenerating liver 3 (PRL-3) is a new target in colorectal cancer, mediating metastatic behavior through a promigratory function. However, detailed explanations for this effect have remained elusive. Here we show that PRL-3 interacts with the ADP-ribosylation factor 1 (Arf1). PRL-3 colocalizes with Arf1 in an endosomal compartment and associates with transmembrane proteins such as the transferrin receptor and α5 integrins. PRL-3 interacts with Arf1 through a distinct motif and regulates activation of Arf1. PRL-3-mediated migration depends on expression and activation of Arf1 and is sensitive to treatment with Brefeldin A. We also demonstrate that PRL-3 modulates recycling of α5 integrins and that its phosphatase activity as well as Arf activation and compartmentalization with Arf1 are required for this effect. In summary our data identify a new function for PRL-3 and show that Arf1 is a new PRL-3-dependent mediator of enhanced migration of cancer cells through enhanced recycling of matrix receptors.

  4. Rac1 activation driven by 14-3-3ζ dimerization promotes prostate cancer cell-matrix interactions, motility and transendothelial migration.

    PubMed

    Goc, Anna; Abdalla, Maha; Al-Azayzih, Ahmad; Somanath, Payaningal R

    2012-01-01

    14-3-3 proteins are ubiquitously expressed dimeric adaptor proteins that have emerged as key mediators of many cell signaling pathways in multiple cell types. Its effects are mainly mediated by binding to selective phosphoserine/threonine proteins. The importance of 14-3-3 proteins in cancer have only started to become apparent and its exact role in cancer progression as well as the mechanisms by which 14-3-3 proteins mediate cancer cell function remain unknown. While protein 14-3-3σ is widely accepted as a tumor suppressor, 14-3-3ζ, β and γ isoforms have been shown to have tumor promoting effects. Despite the importance of 14-3-3 family in mediating various cell processes, the exact role and mechanism of 14-3-3ζ remain unexplored. In the current study, we investigated the role of protein 14-3-3ζ in prostate cancer cell motility and transendothelial migration using biochemical, molecular biology and electric cell-substrate impedance sensing approaches as well as cell based functional assays. Our study indicated that expression with wild-type protein 14-3-3ζ significantly enhanced Rac activity in PC3 cells. In contrast, expression of dimer-resistant mutant of protein 14-3-3ζ (DM-14-3-3) inhibited Rac activity and associated phosphorylation of p21 activated kinase-1 and 2. Expression with wild-type 14-3-3ζ or constitutively active Rac1 enhanced extracellular matrix recognition, lamellipodia formation, cell migration and trans-endothelial migration by PC3 cells. In contrast, expression with DM 14-3-3ζ or DN-Rac1 in PC3 cells significantly inhibited these cell functions. Our results demonstrate for the first time that 14-3-3ζ enhances prostate cancer cell-matrix interactions, motility and transendothelial migration in vitro via activation of Rac1-GTPase and is an important target for therapeutic interventions for prostate cancer.

  5. Phosphorylation of the cool-1/beta-Pix protein serves as a regulatory signal for the migration and invasive activity of Src-transformed cells.

    PubMed

    Feng, Qiyu; Baird, Dan; Yoo, Sungsoo; Antonyak, Marc; Cerione, Richard A

    2010-06-11

    Previously we showed that Cool-1 (Cloned out of library-1)/beta-Pix (Pak-interactive exchange factor) is phosphorylated at a specific tyrosine residue (Tyr-442) in a Src-dependent manner and serves as a dual function guanine nucleotide exchange factor (GEF)/signaling-effector for Cdc42 that is essential for transformation by Src. Here, we show that knocking-down Cool-1 or overexpressing a Cool-1 mutant that contains substitutions within its Dbl homology domain and is defective for GEF activity, inhibits Src-promoted cell migration. Similarly, the expression of a Cool-1 mutant containing a tyrosine to phenylalanine substitution at position 442, making it incapable of being phosphorylated in response to serum, epidermal growth factor (EGF), or Src, also causes a significant inhibition of the migration and invasive activity of cells expressing oncogenic Src. We further demonstrate that the phosphorylation of Cool-1 at Tyr-442 weakens its ability to bind to one of its primary interaction-partners, Cat-1 (Cool-associated tyrosine phosphosubstrate-1)/Git-1 (G protein-coupled receptor kinase-interactor-1), thus making Cat more accessible for binding to paxillin. This enables cells to alternate between states where they contain large numbers of focal complexes (i.e. conditions favoring Cool-1-Cat interactions) versus reduced numbers of focal complexes (conditions favoring Cat-paxillin interactions). Overall, these findings show that the phosphorylation-dephosphorylation cycle of Cool-1 at Tyr-442 can serve as a key regulatory signal for focal complex assembly-disassembly, and consequently, for the migration and invasive activity of Src-transformed cells.

  6. Leukotactin-1/CCL15 induces cell migration and differentiation of human eosinophilic leukemia EoL-1 cells through PKCdelta activation.

    PubMed

    Lee, Ji-Sook; Kim, In Sik

    2010-06-01

    Leukotactin-1 (Lkn-1)/CCL15 is a CC chemokine that binds to the CCR1 and CCR3. Lkn-1 functions as an essential factor in the migration of monocytes, lymphocytes, and neutrophils. Although eosinophils express both receptors, the role of Lkn-1 in immature eosinophils remains to be elucidated. In this present study, we investigated the contribution of the CCR1-binding chemokines to chemotactic activity and in the differentiation in the human eosinophilic leukemia cell line EoL-1. Lkn-1 induced the stronger migration of EoL-1 cells than other CCR1-binding chemokines such as RANTES/CCL5, MIP-1alpha/CCL3 and HCC-4/CCL16. Lkn-1-induced chemotaxis was inhibited by pertussis toxin, an inhibitor of G(i)/G(o) protein; U73122, an inhibitor of phospholipase C and rottlerin, an inhibitor of protein kinase C delta (PKCdelta). Lkn-1 increased PKCdelta activity, which was partially blocked by the pertussis toxin and U73122. Lkn-1 enhanced the butyric acid-induced differentiation via PKCdelta after binding to the increased CCR1 because Lkn-1 caused EoL-1 cells to change morphologically into mature eosinophil-like cells. Likewise, Lkn-1 increased the expression of both eosinophil peroxidase (EPO) and the major basic protein (MBP). PKCdelta activation due to Lkn-1 is involved in migration, as well as the butyric acid-induced differentiation. This finding contributes to an understanding of CC chemokines in eosinophil biology and to the development of novel therapies for the treatment of eosinophilic disorders. This study suggests the pivotal roles of Lkn-1 in the regulation of the movement and development of eosinophils.

  7. FZD6, targeted by miR-21, represses gastric cancer cell proliferation and migration via activating non-canonical wnt pathway.

    PubMed

    Yan, Jin; Liu, Tingyu; Zhou, Xiaoying; Dang, Yini; Yin, Chengqiang; Zhang, Guoxin

    2016-01-01

    FZD6 plays crucial roles in human tumorigenesis. However, its mechanism in regulating cancers has not been fully elucidated. In the study, we found that FZD6 repressed gastric cancer cell proliferation and migration via activating non-canonical wnt pathway. In addition, non-canonical wnt pathway ameliorated expression of canonical wnt pathway. We also demonstrated that the FZD6 was involved in miR-21-dependent effects in the canonical and non-canonical wnt pathways in gastric cancer. These findings provide a better understanding of the development and progression of gastric cancer and may be an important implication for future therapy.

  8. Vibrationally induced center reconfiguration in co-doped GaN:Eu, Mg epitaxial layers: Local hydrogen migration vs. activation of non-radiative channels

    SciTech Connect

    Mitchell, B.; Dierolf, V.; Lee, D.; Lee, D.; Fujiwara, Y.

    2013-12-09

    Europium doped gallium nitride (GaN:Eu) is a promising candidate as a material for red light emitting diodes. When Mg was co-doped into GaN:Eu, additional incorporation environments were discovered that show high excitation efficiency at room temperature and have been attributed to the coupling of Mg-H complexes to the majority Eu site. Electron beam irradiation, indirect and resonant (direct) laser excitation were found to modify these complexes, indicating that vibrational energy alone can trigger the migration of the H while the presence of additional charges and excess energy controls the type of reconfiguration and the activation of non-radiative decay channels.

  9. Vibrationally induced center reconfiguration in co-doped GaN:Eu, Mg epitaxial layers: Local hydrogen migration vs. activation of non-radiative channels

    NASA Astrophysics Data System (ADS)

    Mitchell, B.; Lee, D.; Lee, D.; Fujiwara, Y.; Dierolf, V.

    2013-12-01

    Europium doped gallium nitride (GaN:Eu) is a promising candidate as a material for red light emitting diodes. When Mg was co-doped into GaN:Eu, additional incorporation environments were discovered that show high excitation efficiency at room temperature and have been attributed to the coupling of Mg-H complexes to the majority Eu site. Electron beam irradiation, indirect and resonant (direct) laser excitation were found to modify these complexes, indicating that vibrational energy alone can trigger the migration of the H while the presence of additional charges and excess energy controls the type of reconfiguration and the activation of non-radiative decay channels.

  10. Clonorchis sinensis excretory-secretory products promote the migration and invasion of cholangiocarcinoma cells by activating the integrin β4-FAK/Src signaling pathway.

    PubMed

    Pak, Jhang Ho; Bashir, Qudsia; Kim, In Ki; Hong, Sung-Jong; Maeng, Sejung; Bahk, Young Yil; Kim, Tong-Soo

    2017-03-08

    Cholangiocarcinoma (CCA) is a slow-growing but highly metastatic cancer. Its metastatic potential largely explains its high mortality rate. A recognized risk factor for CCA development is infection with the liver flukes Opisthorchis viverrini and Clonorchis sinensis. We previously reported that the excretory-secretory products (ESPs) of C. sinensis promoted the three-dimensional aggregation and invasion of CCA cells. In the present study, a quantitative real-time PCR array of extracellular matrix (ECM) and adhesion molecules was used to examine the regulatory mechanism of ESP-mediated CCA cell migration and invasion. In particular, the expression levels of integrin α isoforms and β4 were upregulated in response to ESPs. Increased expression of integrin β4 was probably correlated with activation of focal adhesion kinase (FAK) and the steroid receptor coactivator (Src) family kinase and the subsequent activation of two downstream focal adhesion molecules, paxillin and vinculin. Moreover, inhibition of FAK/Src activation reduced paxillin and vinculin phosphorylation and attenuated ESP-induced CCA cell migration and invasion. These findings suggest that the integrin β4-FAK/Src signaling axis may play a crucial role in clonorchiasis-associated CCA metastasis during tumor progression.

  11. Actin depolymerization mediated loss of SNTA1 phosphorylation and Rac1 activity has implications on ROS production, cell migration and apoptosis.

    PubMed

    Bhat, Sehar Saleem; Parray, Arif Ali; Mushtaq, Umar; Fazili, Khalid Majid; Khanday, Firdous Ahmad

    2016-06-01

    Alpha-1-syntrophin (SNTA1) and Rac1 are part of a signaling pathway via the dystrophin glycoprotein complex (DGC). Both SNTA1 and Rac1 proteins are over-expressed in various carcinomas. It is through the DGC signaling pathway that SNTA1 has been shown to act as a link between the extra cellular matrix, the internal cell signaling apparatus and the actin cytoskeleton. SNTA1 is involved in the modulation of the actin cytoskeleton and actin reorganization. Rac1 also controls actin cytoskeletal organization in the cell. In this study, we present the interplay between f-actin, SNTA1 and Rac1. We analyzed the effect of actin depolymerization on SNTA1 tyrosine phosphorylation and Rac1 activity using actin depolymerizing drugs, cytochalasin D and latrunculin A. Our results indicate a marked decrease in the tyrosine phosphorylation of SNTA1 upon actin depolymerization. Results suggest that actin depolymerization mediated loss of SNTA1 phosphorylation leads to loss of interaction between SNTA1 and Rac1, with a concomitant loss of Rac1 activation. The loss of SNTA1tyrosine phosphorylation and Rac1 activity by actin depolymerization results in increased apoptosis, decreased cell migration and decreased reactive oxygen species (ROS) levels in breast carcinoma cells. Collectively, our results present a possible role of f-actin in the SNTA1-Rac1 signaling pathway and implications of actin depolymerization on cell migration, ROS production and apoptosis.

  12. Activation of P2X7 and P2Y11 purinergic receptors inhibits migration and normalizes tumor-derived endothelial cells via cAMP signaling

    PubMed Central

    Avanzato, D.; Genova, T.; Fiorio Pla, A.; Bernardini, M.; Bianco, S.; Bussolati, B.; Mancardi, D.; Giraudo, E.; Maione, F.; Cassoni, P.; Castellano, I.; Munaron, L.

    2016-01-01

    Purinergic signaling is involved in inflammation and cancer. Extracellular ATP accumulates in tumor interstitium, reaching hundreds micromolar concentrations, but its functional role on tumor vasculature and endothelium is unknown. Here we show that high ATP doses (>20 μM) strongly inhibit migration of endothelial cells from human breast carcinoma (BTEC), but not of normal human microvascular EC. Lower doses (1–10 mm result ineffective. The anti-migratory activity is associated with cytoskeleton remodeling and is significantly prevented by hypoxia. Pharmacological and molecular evidences suggest a major role for P2X7R and P2Y11R in ATP-mediated inhibition of TEC migration: selective activation of these purinergic receptors by BzATP mimics the anti-migratory effect of ATP, which is in turn impaired by their pharmacological or molecular silencing. Downstream pathway includes calcium-dependent Adenilyl Cyclase 10 (AC10) recruitment, cAMP release and EPAC-1 activation. Notably, high ATP enhances TEC-mediated attraction of human pericytes, leading to a decrease of endothelial permeability, a hallmark of vessel normalization. Finally, we provide the first evidence of in vivo P2X7R expression in blood vessels of murine and human breast carcinoma. In conclusion, we have identified a purinergic pathway selectively acting as an antiangiogenic and normalizing signal for human tumor-derived vascular endothelium. PMID:27586846

  13. Gremlin promotes retinal pigmentation epithelial (RPE) cell proliferation, migration and VEGF production via activating VEGFR2-Akt-mTORC2 signaling

    PubMed Central

    Liu, Yuan; Chen, Zhijun; Cheng, Haixia; Chen, Juan; Qian, Jing

    2017-01-01

    Retinopathy of prematurity (ROP) is characterized by late-phase pathologic retinal vasoproliferation. Gremlin is a novel vascular endothelial growth factors (VEGF) receptor 2 (VEGFR2) agonist and promotes angiogenic response. We demonstrated that gremlin expression was significantly increased in retinas of ROP model mice, which was correlated with VEGF upregulation. In retinal pigmentation epithelial (RPE) cells, gremlin activated VEGFR2-Akt-mTORC2 (mammalian target of rapamycin complex 2) signaling, and promoted cell proliferation, migration and VEGF production. VEGFR inhibition (by SU5416) or shRNA knockdown almost abolished gremlin-mediated pleiotropic functions in RPE cells. Further, pharmacological inhibition of Akt-mTOR, or shRNA knockdown of key mTORC2 component (Rictor or Sin1) also attenuated gremlin-exerted activities in RPE cells. We conclude that gremlin promotes RPE cell proliferation, migration and VEGF production possibly via activating VEGFR2-Akt-mTORC2 signaling. Gremlin could be a novel therapeutic target of ROP or other retinal vasoproliferation diseases. PMID:27894090

  14. B-9-3, a novel β-carboline derivative exhibits anti-cancer activity via induction of apoptosis and inhibition of cell migration in vitro.

    PubMed

    Daoud, Abdelkader; Song, Jing; Xiao, Feiyang; Shang, Jing

    2014-02-05

    Peganum harmala L is an important medicinal plant that has been used from ancient time due to its alkaloids rich of ß-carbolines. Harmane is a naturally occurring ß-carboline extracted from Peganum harmala L, that exhibits a wide range of biological, psychopharmacological, and toxicological actions. The synthesis of novel derivatives with high anti-cancer activity and less side effects is necessary. In the present study, B-9-3-a semi-synthetic compound that is formed of two harmane molecules bound by a butyl group-showed a strong anti-cancer activity against a human lung cancer cell line, a human breast cancer cell line, and a human colorectal carcinoma cell line. B-9-3 anti-proliferative effect followed a similar pattern in the three cell lines. This pattern includes a dose-dependent induction of apoptosis, or necroptosis as confirmed by Hoechst staining, flow cytometry and western blot analyses, and the inhibition of cancer cells migration that was shown to be dependent on the drug׳s concentration as well. Moreover, B-9-3 inhibited tube formation in human umbilical vascular endothelial cell line (HUVEC), which indicates an anti-angiogenesis activity in vitro. In summary, B-9-3, a semi-synthetic derivative of ß-carboline, has an anti-proliferative effect against tumor cells via induction of apoptosis and inhibition of cell migration.

  15. Cyclosporin A promotes proliferating cell nuclear antigen expression and migration of human cytotrophoblast cells via the mitgen-activated protein kinase-3/1-mediated nuclear factor-κB signaling pathways.

    PubMed

    Wang, Song-Cun; Yu, Min; Li, Yan-Hong; Piao, Hai-Lan; Tang, Chuan-Lin; Sun, Chan; Zhu, Rui; Li, Ming Qing; Jin, Li-Ping; Li, Da-Jin; Du, Mei-Rong

    2013-01-01

    Our previous studies have demonstrated that cyclosporin A (CsA) promotes the proliferation and migration of human trophoblasts via the mitgen-activated protein kinase-3/1 (MAPK3/1) pathway. In the present study, we further investigated the role of nuclear factor (NF)-κB in the CsA-induced trophoblast proliferating cell nuclear antigen (PCNA) expression and migration, and its relationship to MAPK3/1 signal. Flow cytometry was used to analyze the expression of PCNA in trophoblasts. The migration of human primary trophoblasts was determined by wound-healing assay and transwell migration assay. Western blot analysis was performed to evaluate the activation of NF-κB p65 and NF-κB inhibitory protein I-κB in human trophoblasts. We found that treatment with CsA promotes PCNA expression and migration of human trophoblast in a dose-associated manner. Blocking of the MAPK3/1 signal abrogated the enhanced PCNA expression and migration in trophoblasts by CsA. In addition, CsA increased the phosphorylation of NF-κB p65 and the inhibitor I-κB in human trophoblasts in a time-related manner. Pretreatment with MAPK3/1 inhibitor U0126 abrogated the phosphorylation of NF-κB p65 and I-κB. Accordingly, the CsA-induced enhancement of PCNA expression and migration in trophoblasts was also decreased. This CsA-induced enhancement in the expression and migration of trophoblasts was abolished by pretreatment with pyrrolidine dithiocarbamate, a specific NF-κB inhibitor. Thus, our results suggest that CsA promotes PCNA expression and migration of human trophoblasts via MAPK-mediated NF-κB activation.

  16. Use of electromyogram telemetry to assess swimming activity of adult spring Chinook salmon migrating past a Columbia River dam

    USGS Publications Warehouse

    Brown, R.S.; Geist, D.R.; Mesa, M.G.

    2006-01-01

    Electromyogram (EMG) radiotelemetry was used to estimate the swim speeds of spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam, and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were then released below Bonneville Dam and radio-tracked as they migrated through the tailraces, fishways, and forebays of the dam. On average, swim speed was significantly higher when tagged salmon were moving through tailraces than when they were moving through other parts of the dam. Specifically, swim speeds for fish in tailraces (106.4 cm/s) were 23% higher than those of fish in fishways (84.9 cm/s) and 32% higher than those of fish in forebays (80.2 cm/s). Swim speeds were higher in fishways during the day than during the night, but there were no diel differences in swim speeds in tailraces and forebays. During dam passage, Chinook salmon spent the most time in tailraces, followed by fishways and forebays. ?? Copyright by the American Fisheries Society 2006.

  17. Use of Electromyogram Telemetry to Assess Swimmng Activity of Adult Spring Chinook Salmon Migrating Past a Columbia River Dam

    SciTech Connect

    Brown, Richard S.; Geist, David R.; Mesa, Matthew G.

    2006-02-28

    Electromyogram (EMG) radiotelemetry was used to examine the amount of energy expended by spring Chinook salmon Oncorhynchus tshawytscha migrating upstream past a Columbia River dam. Electrodes from EMG transmitters were surgically implanted in the red muscle of fish captured at Bonneville Dam and output from the tags was calibrated to defined swim speeds for each fish in a tunnel respirometer. The fish were then released below Bonneville Dam and radio-tracked as they migrated through the tailraces, fishways, and forebays of the dam. On average, the rate of aerobic energy used by spring Chinook salmon was significantly higher when they were moving through tailraces (1.27 kcal•kg-1•h-1) than when they were moving through other parts of the dam. Specifically, the rate of aerobic energy use for fish in tailraces was 14% higher than that used by fish in fishways (1.11 kcal•kg-1•h-1) and 27% higher than the rate used by fish in forebays (1.00 kcal•kg-1•h-1). Most (80%) of the aerobic energy used by fish to pass this dam was expended in the tailrace (25.5 kcal/kg), while only 18% (5.6 kcal/kg) and 2% (0.6 kcal/kg) were used in the fishways and forebays.

  18. Selected activities of Citrus maxima Merr. fruits on human endothelial cells: enhancing cell migration and delaying cellular aging.

    PubMed

    Buachan, Paiwan; Chularojmontri, Linda; Wattanapitayakul, Suvara K

    2014-04-21

    Endothelial injury and damage as well as accumulated reactive oxygen species (ROS) in aging play a significant role in the development of cardiovascular disease (CVD). Recent studies show an association of high citrus fruit intake with a lower risk of CVD and stroke but the mechanisms involved are not fully understood. This study investigated the effects of pummelo (Citrus maxima Merr. var. Tubtim Siam, CM) fruit extract on human umbilical vein endothelial cell (HUVECs) migration and aging. The freeze-dried powder of fruit extract was characterized for antioxidant capacity (FRAP assay) and certain natural antioxidants, including ascorbic acid, gallic acid, hesperidin, and naringin (HPLC). Short-term (48 h) co-cultivation of HUVECs with CM enhanced cell migration as evaluated by a scratch wound assay and Boyden chamber assay. A long-term treatment with CM for 35 days significantly increased HUVEC proliferation capability as indicated by population doubling level (PDL). CM also delayed the onset of aging phenotype shown by senescence-associated β-galactosidase (SA-β-gal) staining. Furthermore, CM was able to attenuate increased ROS levels in aged cells when determined by 2',7'-dichlorodihydrofluorescein diacetate (DCDHF) while eNOS mRNA expression was increased but the eNOS protein level was not changed. Thus, further in vivo and clinical studies are warranted to support the use of pummelo as a functional fruit for endothelial health and CVD risk reduction.

  19. The requirement of SEPT2 and SEPT7 for migration and invasion in human breast cancer via MEK/ERK activation

    PubMed Central

    Fan, Ning; Zhang, Qian; Wang, Weijie; Zheng, Mingnan; Ma, Lingfei; Li, Yan; Shi, Lei

    2016-01-01

    Septins are a novel class of GTP-binding cytoskeletal proteins evolutionarily conserved from yeast to mammals and have now been found to play a contributing role in a broad range of tumor types. However, their functional importance in breast cancer remains largely unclear. Here, we demonstrated that pharmaceutical inhibition of global septin dynamics would greatly suppress proliferation, migration and invasiveness in breast cancer cell lines. We then examined the expression and subcellular distribution of the selected septins SEPT2 and SEPT7 in breast cancer cells, revealing a rather variable localization of the two proteins with cell cycle progression. To determine the role of both septins in mediating malignant behavior of cancer cells, we used RNA silencing to specifically deplete endogenous SEPT2 or SEPT7 in highly invasive breast cancer cell line MDA-MB-231. Our findings showed that SEPT2/7 depletion had virtually identical inhibitory effects on cellular proliferation, apoptosis, migration and invasion. Moreover, the opposite performance in migration and invasion was observed after enforced expression of SEPT2/7 in the same cell line. We further demonstrated MEK/ERK activation, but not other MAPKs and AKT, was positively correlated with the protein levels of SEPT2 and SEPT7. Additionally, in SEPT2/7-overexpressing cells, the MEK specific inhibitor U0126 was able to correct the high active status of MEK/ERK while normalizing the increased invasive behaviors of these cells. Taken together, these results strongly suggest that SEPT2 and SEPT7 are involved in breast carcinogenesis and may serve as valuable therapeutic targets for breast cancer. PMID:27557506

  20. Exogenous hydrogen sulfide exerts proliferation, anti-apoptosis, migration effects and accelerates cell cycle progression in multiple myeloma cells via activating the Akt pathway.

    PubMed

    Zheng, Dong; Chen, Ziang; Chen, Jingfu; Zhuang, Xiaomin; Feng, Jianqiang; Li, Juan

    2016-10-01

    Hydrogen sulfide (H2S), regarded as the third gaseous transmitter, mediates and induces various biological effects. The present study investigated the effects of H2S on multiple myeloma cell progression via amplifying the activation of Akt pathway in multiple myeloma cells. The level of H2S produced in multiple myeloma (MM) patients and healthy subjects was measured using enzyme-linked immunosorbent assay (ELISA). MM cells were treated with 500 µmol/l NaHS (a donor of H2S) for 24 h. The expression levels of phosphorylated-Akt (p-Akt), Bcl-2 and caspase-3 were measured by western blot assay. Cell viability was detected by Cell Counting Kit 8 (CCK-8). The cell cycle was analyzed by flow cytometry. Our results show that the concentration of H2S was higher in MM patients and that it increased in parallel with disease progression. Treating MM cells with 500 µmol/l NaHS for 24 h markedly increased the expression level of Bcl-2 and the activation of p-Akt, however, the expression level of caspase-3 was decreased, cell viability was increased, and cell cycle progression was accelerated in MM cells. NaHS also induced migration in MM cells in transwell migration assay. Furthermore, co-treatment of MM cells with 500 µmol/l NaHS and 50 µmol/l LY294002 for 24 h significantly overset these effects. In conclusion, our findings demonstrate that the Akt pathway contributes to NaHS-induced cell proliferation, migration and acceleration of cell cycle progression in MM cells.

  1. Vitamin D Binding Protein-Macrophage Activating Factor Directly Inhibits Proliferation, Migration, and uPAR Expression of Prostate Cancer Cells

    PubMed Central

    Bielenberg, Diane R.; Dridi, Sami; Wu, Jason; Jiang, Weihua; Huang, Bin; Pirie-Shepherd, Steven; Fannon, Michael

    2010-01-01

    Background Vitamin D binding protein-macrophage activating factor (DBP-maf) is a potent inhibitor of tumor growth. Its activity, however, has been attributed to indirect mechanisms such as boosting the immune response by activating macrophages and inhibiting the blood vessel growth necessary for the growth of tumors. Methods and Findings In this study we show for the first time that DBP-maf exhibits a direct and potent effect on prostate tumor cells in the absence of macrophages. DBP-maf demonstrated inhibitory activity in proliferation studies of both LNCaP and PC3 prostate cancer cell lines as well as metastatic clones of these cells. Flow cytometry studies with annexin V and propidium iodide showed that this inhibitory activity is not due to apoptosis or cell death. DBP-maf also had the ability to inhibit migration of prostate cancer cells in vitro. Finally, DBP-maf was shown to cause a reduction in urokinase plasminogen activator receptor (uPAR) expression in prostate tumor cells. There is evidence that activation of this receptor correlates with tumor metastasis. Conclusions These studies show strong inhibitory activity of DBP-maf on prostate tumor cells independent of its macrophage activation. PMID:20976141

  2. Uridine adenosine tetraphosphate (Up{sub 4}A) is a strong inductor of smooth muscle cell migration via activation of the P2Y{sub 2} receptor and cross-communication to the PDGF receptor

    SciTech Connect

    Wiedon, Annette; Toelle, Markus; Bastine, Joschika; Schuchardt, Mirjam; Huang, Tao; Jankowski, Vera; Jankowski, Joachim; Zidek, Walter; Giet, Markus van der

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer Up{sub 4}A induces VSMC migration. Black-Right-Pointing-Pointer VSMC migration towards Up{sub 4}A involves P2Y{sub 2} activation. Black-Right-Pointing-Pointer Up{sub 4}A-induced VSMC migration is OPN-dependent. Black-Right-Pointing-Pointer Activation of ERK1/2 pathway is necessary for VSMC migration towards Up{sub 4}A. Black-Right-Pointing-Pointer Up{sub 4}A-directed VSMC migration cross-communicates with the PDGFR. -- Abstract: The recently discovered dinucleotide uridine adenosine tetraphosphate (Up{sub 4}A) was found in human plasma and characterized as endothelium-derived vasoconstrictive factor (EDCF). A further study revealed a positive correlation between Up{sub 4}A and vascular smooth muscle cell (VSMC) proliferation. Due to the dominant role of migration in the formation of atherosclerotic lesions our aim was to investigate the migration stimulating potential of Up{sub 4}A. Indeed, we found a strong chemoattractant effect of Up{sub 4}A on VSMC by using a modified Boyden chamber. This migration dramatically depends on osteopontin secretion (OPN) revealed by the reduction of the migration signal down to 23% during simultaneous incubation with an OPN-blocking antibody. Due to inhibitory patterns using specific and unspecific purinoreceptor inhibitors, Up{sub 4}A mediates it's migratory signal mainly via the P2Y{sub 2}. The signaling behind the receptor was investigated with luminex technique and revealed an activation of the extracellular signal-regulated kinases 1 and 2 (ERK1/2) pathway. By use of the specific PDGF receptor (PDGFR) inhibitor AG1296 and siRNA technique against PDGFR-{beta} we found a strongly reduced migration signal after Up{sub 4}A stimulation in the PDGFR-{beta} knockdown cells compared to control cells. In this study, we present substantiate data that Up{sub 4}A exhibits migration stimulating potential probably involving the signaling cascade of MEK1 and ERK1/2 as well as the matrix protein OPN. We

  3. The circular migration of smallholders in Kenya.

    PubMed

    Bigsten, A

    1996-01-01

    Circular migration is a central phenomenon in the lives of smallholders in East Africa. Many migration decisions are not individual decisions, but rather household decisions in which the household allocates its labor force among activities to maximize household utility. A probit model which incorporates circular migration and takes into account contacts, information, and indivisibilities is used to analyze migration among 763 farm households in the Central and Nyanza provinces of Kenya. Study data are from a 1982 survey. The pull of high urban wages appears to be a far more important determinant of migration decision outcomes than the push of land scarcity, while a strong local nonagricultural economy does not seem to restrict migration. Networks of personal contacts were found to be highly significant determinants of migration. These findings suggest that rural development will probably not reduce the flow of migration.

  4. Episodic bedrock erosion by gully-head migration, Colorado High Plains, USA

    USGS Publications Warehouse

    Rengers, Francis; Tucker, G.E.; Mahan, Shannon

    2016-01-01

    This study explores the frequency of bedrock exposure in a soil-mantled low-relief (i.e. non-mountainous) landscape. In the High Plains of eastern Colorado, gully headcuts are among the few erosional features that will incise through the soil mantle to expose bedrock. We measured the last time of bedrock exposure using optically stimulated luminescence dating of alluvial sediment overlying bedrock in gully headcuts. Our dating suggests that headcuts in adjacent gullies expose bedrock asynchronously, and therefore, the headcuts are unlikely to have been triggered by a base-level drop in the trunk stream. This finding supports the hypothesis that headcuts can develop locally in gullies as a result of focused scour in locations where hydraulic stress during a flash flood is sufficiently high, and/or ground cover is sufficiently weak, to generate a scour hole that undermines vegetation. Alluvium dating also reveals that gullies have been a persistent part of this landscape since the early Holocene. 

  5. Downregulation of microRNA-122 promotes proliferation, migration, and invasion of human hepatocellular carcinoma cells by activating epithelial–mesenchymal transition

    PubMed Central

    Wang, Nanyao; Wang, Qiong; Shen, Dong; Sun, Xia; Cao, Xiangming; Wu, Dan

    2016-01-01

    Objective To investigate the effects of microRNA-122 (miR-122) on proliferation, migration, and invasion in human hepatocellular carcinoma (HCC) cells by activating epithelial–mesenchymal transition (EMT) pathways. Methods miR-122 mimics, miR-122 inhibitors, relevant control oligonucleotides, and Wnt1 were transfected into HepG2 and huh7 cell lines which were then divided into six groups: miR-122 group, anti-miR-122 group, miR-negative control (NC) group, anti-miR-NC group, miR-122 + Wnt1 group, and miR-122 + vector group. The miR-122 expressions and mRNA expressions of Wnt1 and EMT-related genes (E-cadherin, vimentin, β-cadherin, and N-cadherin) were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Protein expression levels of Wnt1, E-cadherin, vimentin, β-cadherin, and N-cadherin were measured by Western blot. Cell proliferation, migration, and invasion were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, wound-healing assay, and Transwell assay, respectively. Results Dual luciferase reporter gene results showed that Wnt1 is a direct target gene of miR-122 in both HepG2 and huh7 cell lines. Compared to miR-NC, anti-miR-NC, and miR-122 + Wnt1 groups, miR-122 expression was markedly higher in the miR-122 group and miR-122 + vector group, but was sharply decreased in anti-miR-122 group (both P<0.05), and the mRNA and protein levels of Wnt1, vimentin, β-cadherin, and N-cadherin decreased significantly; also E-cadherin increased, and cell proliferation, migration, and invasion decreased in the miR-122 group and miR-122 + vector group (all P<0.05), but the situation was totally reversed in the anti-miR-122 group (all P<0.05). Conclusion Downregulation of miR-122 promoted proliferation, migration, and invasion of human HCC cells by targeting Wnt1 and regulating Wnt/β-catenin pathway which activated the EMT pathways. PMID:27103830

  6. NEU1 and NEU3 sialidase activity expressed in human lung microvascular endothelia: NEU1 restrains endothelial cell migration, whereas NEU3 does not.

    PubMed

    Cross, Alan S; Hyun, Sang Won; Miranda-Ribera, Alba; Feng, Chiguang; Liu, Anguo; Nguyen, Chinh; Zhang, Lei; Luzina, Irina G; Atamas, Sergei P; Twaddell, William S; Guang, Wei; Lillehoj, Erik P; Puché, Adam C; Huang, Wei; Wang, Lai-Xi; Passaniti, Antonino; Goldblum, Simeon E

    2012-05-04

    The microvascular endothelial surface expresses multiple molecules whose sialylation state regulates multiple aspects of endothelial function. To better regulate these sialoproteins, we asked whether endothelial cells (ECs) might express one or more catalytically active sialidases. Human lung microvascular EC lysates contained heat-labile sialidase activity for a fluorogenic substrate, 2'-(4-methylumbelliferyl)-α-D-N-acetylneuraminic acid (4-MU-NANA), that was dose-dependently inhibited by the competitive sialidase inhibitor, 2,3-dehydro-2-deoxy-N-acetylneuraminic acid but not its negative control. The EC lysates also contained sialidase activity for a ganglioside mixture. Using real time RT-PCR to detect mRNAs for the four known mammalian sialidases, NEU1, -2, -3, and -4, NEU1 mRNA was expressed at levels 2700-fold higher that those found for NEU2, -3, or -4. Western analyses indicated NEU1 and -3 protein expression. Using confocal microscopy and flow cytometry, NEU1 was immunolocalized to both the plasma membrane and the perinuclear region. NEU3 was detected both in the cytosol and nucleus. Prior siRNA-mediated knockdown of NEU1 and NEU3 each decreased EC sialidase activity for 4-MU-NANA by >65 and >17%, respectively, and for the ganglioside mixture by 0 and 40%, respectively. NEU1 overexpression in ECs reduced their migration into a wound by >40%, whereas NEU3 overexpression did not. Immunohistochemical studies of normal human tissues immunolocalized NEU1 and NEU3 proteins to both pulmonary and extrapulmonary vascular endothelia. These combined data indicate that human lung microvascular ECs as well as other endothelia express catalytically active NEU1 and NEU3. NEU1 restrains EC migration, whereas NEU3 does not.

  7. Bone marrow mesenchymal stem cells express a restricted set of functionally active chemokine receptors capable of promoting migration to pancreatic islets.

    PubMed

    Sordi, Valeria; Malosio, Maria Luisa; Marchesi, Federica; Mercalli, Alessia; Melzi, Raffaella; Giordano, Tiziana; Belmonte, Nathalie; Ferrari, Giuliana; Leone, Biagio Eugenio; Bertuzzi, Federico; Zerbini, Gianpaolo; Allavena, Paola; Bonifacio, Ezio; Piemonti, Lorenzo

    2005-07-15

    Bone marrow-derived mesenchymal stem cells (BM-MSCs) are stromal cells with the ability to proliferate and differentiate into many tissues. Although they represent powerful tools for several therapeutic settings, mechanisms regulating their migration to peripheral tissues are still unknown. Here, we report chemokine receptor expression on human BM-MSCs and their role in mediating migration to tissues. A minority of BM-MSCs (2% to 25%) expressed a restricted set of chemokine receptors (CXC receptor 4 [CXCR4], CX3C receptor 1 [CX3CR1], CXCR6, CC chemokine receptor 1 [CCR1], CCR7) and, accordingly, showed appreciable chemotactic migration in response to the chemokines CXC ligand 12 (CXCL12), CX3CL1, CXCL16, CC chemokine ligand 3 (CCL3), and CCL19. Using human pancreatic islets as an in vitro model of peripheral tissue, we showed that islet supernatants released factors able to attract BM-MSCs in vitro, and this attraction was principally mediated by CX3CL1 and CXCL12. Moreover, cells with features of BM-MSCs were detected within the pancreatic islets of mice injected with green fluorescent protein (GFP)-positive BM. A population of bona fide MSCs that also expressed CXCR4, CXCR6, CCR1, and CCR7 could be isolated from normal adult human pancreas. This study defines the chemokine receptor repertoire of human BM-MSCs that determines their migratory activity. Modulation of homing capacity may be instrumental for harnessing the therapeutic potential of BM-MSCs.

  8. Beta-Adrenoceptor Activation Reduces Both Dermal Microvascular Endothelial Cell Migration via a cAMP-Dependent Mechanism and Wound Angiogenesis

    PubMed Central

    O'Leary, Andrew P; Fox, James M; Pullar, Christine E

    2015-01-01

    Angiogenesis is an essential process during tissue regeneration; however, the amount of angiogenesis directly correlates with the level of wound scarring. Angiogenesis is lower in scar-free foetal wounds while angiogenesis is raised and abnormal in pathophysiological scarring such as hypertrophic scars and keloids. Delineating the mechanisms that modulate angiogenesis and could reduce scarring would be clinically useful. Beta-adrenoceptors (β-AR) are G protein-coupled receptors (GPCRs) expressed on all skin cell-types. They play a role in wound repair but their specific role in angiogenesis is unknown. In this study, a range of in vitro assays (single cell migration, scratch wound healing, ELISAs for angiogenic growth factors and tubule formation) were performed with human dermal microvascular endothelial cells (HDMEC) to investigate and dissect mechanisms underpinning β-AR-mediated modulation of angiogenesis in chick chorioallantoic membranes (CAM) and murine excisional skin wounds. β-AR activation reduced HDMEC migration via cyclic adenosine monophosphate (cAMP)-dependent and protein kinase A (PKA)-independent mechanisms as demonstrated through use of an EPAC agonist that auto-inhibited the cAMP-mediated β-AR transduced reduction in HDMEC motility; a PKA inhibitor was, conversely, ineffective. ELISA studies demonstrated that β-AR activation reduced pro-angiogenic growth factor secretion from HDMECs (fibroblast growth factor 2) and keratinocytes (vascular endothelial growth factor A) revealing possible β-AR-mediated autocrine and paracrine anti-angiogenic mechanisms. In more complex environments, β-AR activation delayed HDMEC tubule formation and decreased angiogenesis both in the CAM assay and in murine excisional skin wounds in vivo. β-AR activation reduced HDMEC function in vitro and angiogenesis in vivo; therefore, β-AR agonists could be promising anti-angiogenic modulators in skin. J. Cell. Physiol. 230: 356–365, 2015. © 2014 The Authors. Journal

  9. Ellagitannin-rich cloudberry inhibits hepatocyte growth factor induced cell migration and phosphatidylinositol 3-kinase/AKT activation in colon carcinoma cells and tumors in Min mice

    PubMed Central

    Pajari, Anne-Maria; Päivärinta, Essi; Paavolainen, Lassi; Vaara, Elina; Koivumäki, Tuuli; Garg, Ritu; Heiman-Lindh, Anu; Mutanen, Marja; Marjomäki, Varpu; Ridley, Anne J.

    2016-01-01

    Berries have been found to inhibit colon carcinogenesis in animal models, and thus represent a potential source of compounds for prevention and treatment of colorectal cancer. The mechanistic basis for their effects is not well understood. We used human colon carcinoma cells and Min mice to investigate the effects of ellagitannin-rich cloudberry (Rubus chamaemorus) extract on cancer cell migration and underlying cell signaling. Intrinsic and hepatocyte growth factor (HGF) -induced cell motility in human HT29 and HCA7 colon carcinoma cells was assessed carrying out cell scattering and scratch wound healing assays using time-lapse microscopy. Activation of Met, AKT, and ERK in cell lines and tumors of cloudberry-fed Min mice were determined using immunoprecipitation, Western blot and immunohistochemical analyses. Cloudberry extract significantly inhibited particularly HGF-induced cancer cell migration in both cell lines. Cloudberry extract inhibited the Met receptor tyrosine phosphorylation by HGF and strongly suppressed HGF-induced AKT and ERK activation in both HT29 and HCA7 cells. Consistently, cloudberry feeding (10% w/w freeze-dried berries in diet for 10 weeks) reduced the level of active AKT and prevented phosphoMet localization at the edges in tumors of Min mice. These results indicate that cloudberry reduces tumor growth and cancer cell motility by inhibiting Met signaling and consequent activation of phosphatidylinositol 3-kinase/AKT in vitro and in tumors in vivo. As the Met receptor is recognized to be a major target in cancer treatment, our results suggest that dietary phytochemicals may have therapeutic value in reducing cancer progression and metastasis. PMID:27270323

  10. Activation of GPER suppresses migration and angiogenesis of triple negative breast cancer via inhibition of NF-κB/IL-6 signals.

    PubMed

    Liang, Shuwei; Chen, Zhuojia; Jiang, Guanmin; Zhou, Yan; Liu, Qiao; Su, Qiao; Wei, Weidong; Du, Jun; Wang, Hongsheng

    2017-02-01

    Triple-negative breast cancer (TNBC) is characterized by high vascularity and frequent metastasis. Here, we found that activation of G protein-coupled estrogen receptor (GPER) by its specific agonist G-1 can significantly inhibit interleukin 6 (IL-6) and vascular endothelial growth factor A (VEGF-A). TNBC tissue microarrays from 100 TNBC patients revealed GPER is negatively associated with IL-6 levels and higher grade and stage. Activation of GPER or anti-IL-6 antibody can inhibit both in vitro tube formation of human umbilical vein endothelial cells (HUVECs) and migration of TNBC cells. While recombinant IL-6 supplementary can significantly reverse the inhibitory effects of G-1, suggesting the essential role of IL-6 in G-1 induced suppression of angiogenesis and invasiveness of TNBC cells. G-1 treatment decreased the phosphorylation, nuclear localization, transcriptional activities of NF-κB and suppressed its binding with IL-6 promoter. BAY11-7028, the inhibitor of NF-κB, can mimic the effect of G-1 to suppression of IL-6 and VEGF-A. While over expression of p65 can attenuate the inhibitory effects of G-1 on IL-6 and VEGF expression. The suppression of IL-6 by G-1 can further inhibit HIF-1α and STAT3 signals in TNBC cells by inhibition their expression, phosphorylation and/or nuclear localization. Moreover, G-1 also inhibited the in vivo NF-κB/IL-6 signals and angiogenesis and metastasis of MDA-MB-231 xenograft tumors. In conclusion, our study demonstrated that activation of GPER can suppress migration and angiogenesis of TNBC via inhibition of NF-κB/IL-6 signals, therefore it maybe act as an important target for TNBC treatment.

  11. Role of plasminogen activator inhibitor in the reciprocal regulation of bovine aortic endothelial and smooth muscle cell migration by TGF-beta 1.

    PubMed Central

    Petzelbauer, E.; Springhorn, J. P.; Tucker, A. M.; Madri, J. A.

    1996-01-01

    Vascular endothelial and smooth muscle cells exhibit reciprocal migratory responses after transforming growth factor (TGF)-beta 1 treatment. Endothelial cells exhibit a decreased migratory rate and smooth muscle cells exhibit an increased migratory rate. Previous studies have demonstrated increases in extracellular matrix and integrin synthesis and expression in response to TGF-beta 1. In this report, we illustrate the roles of plasminogen activator inhibitor in modulating the migratory rates in these two cell types. Endothelial cells appear to require a proteolytic phenotype for rapid migration, whereas vascular smooth muscle cells appear to require an anti-proteolytic phenotype. Modulation of proteinase/anti-proteinase activity ratios was accomplished via TGF-beta 1 induction, addition of exogenous plasminogen activator inhibitor, addition of anti-catalytic antibodies directed against urokinase plasminogen activator, overexpression of plasminogen activator inhibitor utilizing stable transfectants, and the use of vitronectin as a substratum. The reciprocal migratory behaviors exhibited by these two vascular cell types in response to TGF-beta 1 is discussed in the context that these two vascular cell types utilize distinct adhesive and signaling pathways in their interactions with extracellular matrix components and responsiveness to proteolytic activity. Images Figure 1 Figure 2 Figure 3 PMID:8780396

  12. Rural-urban migration and changing physical activity among Papua New Guinea highlanders from the perspective of energy expenditure and time use.

    PubMed

    Yamauchi, Taro; Umezaki, Masahiro

    2005-01-01

    We examined the effects of rural-urban migration on nutritional status, daily activity patterns and physical activity levels for a Papua New Guinea Highland population. A large sample (n = 353) of adult males and females was selected for anthropometry and a smaller sample (n = 56) for behavioral observation in conjunction with heart rate monitoring. Urban migrants had higher body mass index and more body fat than their rural counterparts, particularly the females. The physical exertion index calculated for observed activities using heart rate values was much higher in farming activities in the rural area than in sedentary work activities in the urban area. In addition, walking time was notably shorter in the urban group than in the rural group (118 vs 52 min/day in males and 116 vs 29 min/day in females). Consequently, despite the urban group spending a shorter time resting and a longer time working, their daily physical activity level did not achieve the desirable level (1.75-1.80). It is thus necessary for urban residents to increase walking time to about 2 h per day, the level observed in their rural counterparts.

  13. A note on the modelling of circular smallholder migration.

    PubMed

    Bigsten, A

    1988-01-01

    "It is argued that circular migration [in Africa] should be seen as an optimization problem, where the household allocates its labour resources across activities, including work which requires migration, so as to maximize the joint family utility function. The migration problem is illustrated in a simple diagram, which makes it possible to analyse economic aspects of migration."

  14. Activated niacin receptor HCA2 inhibits chemoattractant-mediated macrophage migration via Gβγ/PKC/ERK1/2 pathway and heterologous receptor desensitization

    PubMed Central

    Shi, Ying; Lai, Xiangru; Ye, Lingyan; Chen, Keqiang; Cao, Zheng; Gong, Wanghua; Jin, Lili; Wang, Chunyan; Liu, Mingyong; Liao, Yuan; Wang, Ji Ming; Zhou, Naiming

    2017-01-01

    The niacin receptor HCA2 is implicated in controlling inflammatory host responses with yet poorly understood mechanistic basis. We previously reported that HCA2 in A431 epithelial cells transduced Gβγ-protein kinase C- and Gβγ-metalloproteinase/EGFR-dependent MAPK/ERK signaling cascades. Here, we investigated the role of HCA2 in macrophage-mediated inflammation and the underlying mechanisms. We found that proinflammatory stimulants LPS, IL-6 and IL-1β up-regulated the expression of HCA2 on macrophages. Niacin significantly inhibited macrophage chemotaxis in response to chemoattractants fMLF and CCL2 by disrupting polarized distribution of F-actin and Gβ protein. Niacin showed a selected additive effect on chemoattractant-induced activation of ERK1/2, JNK and PI3K pathways, but only the MEK inhibitor UO126 reduced niacin-mediated inhibition of macrophage chemotaxis, while activation of ERK1/2 by EGF alone did not inhibit fMLF-mediated migration of HEK293T cells co-expressing HCA2 and fMLF receptor FPR1. In addition, niacin induced heterologous desensitization and internalization of FPR1. Furthermore, niacin rescued mice from septic shock by diminishing inflammatory symptoms and the effect was abrogated in HCA2−/− mice. These results suggest that Gβγ/PKC-dependent ERK1/2 activation and heterologous desensitization of chemoattractant receptors are involved in the inhibition of chemoattractant-induced migration of macrophages by niacin. Thus, HCA2 plays a critical role in host protection against pro-inflammatory insults. PMID:28186140

  15. Compilation of data to estimate groundwater migration potential for constituents in active liquid discharges at the Hanford Site

    SciTech Connect

    Ames, L.L.; Serne, R.J.

    1991-03-01

    A preliminary characterization of the constituents present in the 33 liquid waste streams at the US Department of Energy's Hanford Site has been completed by Westinghouse Hanford Company. In addition, Westinghouse Hanford has summarized the soil characteristics based on drill logs collected at each site that receives these liquid wastes. Literature searches were conducted and available Hanford-specific data were tabulated and reviewed. General literature on organic chemicals present in the liquid waste streams was also reviewed. Using all of this information, Pacific Northwest Laboratory has developed a best estimate of the transport characteristics (water solubility and soil adsorption properties) for those radionuclides and inorganic and organic chemicals identified in the various waste streams. We assume that the potential for transport is qualified through the four geochemical parameters: solubility, distribution coefficient, persistence (radiogenic or biochemical half-life), and volatility. Summary tables of these parameters are presented for more than 50 inorganic and radioactive species and more than 50 organic compounds identified in the liquid waste streams. Brief descriptions of the chemical characteristics of Hanford sediments, solubility, and adsorption processes, and of how geochemical parameters are used to estimate migration in groundwater-sediment environments are also presented. Groundwater monitoring data are tabulated for wells neighboring the facilities that receive the liquid wastes. 91 refs., 16 figs., 23 tabs.

  16. Inhibition of RUNX2 Transcriptional Activity Blocks the Proliferation, Migration and Invasion of Epithelial Ovarian Carcinoma Cells

    PubMed Central

    Bachvarova, Magdalena; Gobeil, Stephane; Morin, Chantale; Plante, Marie; Gregoire, Jean; Renaud, Marie-Claude; Sebastianelli, Alexandra; Trinh, Xuan Bich; Bachvarov, Dimcho

    2013-01-01

    Previously, we have identified the RUNX2 gene as hypomethylated and overexpressed in post-chemotherapy (CT) primary cultures derived from serous epithelial ovarian cancer (EOC) patients, when compared to primary cultures derived from matched primary (prior to CT) tumors. However, we found no differences in the RUNX2 methylation in primary EOC tumors and EOC omental metastases, suggesting that DNA methylation-based epigenetic mechanisms have no impact on RUNX2 expression in advanced (metastatic) stage of the disease. Moreover, RUNX2 displayed significantly higher expression not only in metastatic tissue, but also in high-grade primary tumors and even in low malignant potential tumors. Knockdown of the RUNX2 expression in EOC cells led to a sharp decrease of cell proliferation and significantly inhibited EOC cell migration and invasion. Gene expression profiling and consecutive network and pathway analyses confirmed these findings, as various genes and pathways known previously to be implicated in ovarian tumorigenesis, including EOC tumor invasion and metastasis, were found to be downregulated upon RUNX2 suppression, while a number of pro-apoptotic genes and some EOC tumor suppressor genes were induced. Taken together, our data are indicative for a strong oncogenic potential of the RUNX2 gene in serous EOC progression and suggest that RUNX2 might be a novel EOC therapeutic target. Further studies are needed to more completely elucidate the functional implications of RUNX2 and other members of the RUNX gene family in ovarian tumorigenesis. PMID:24124450

  17. The RhoA effector mDia is induced during T cell activation and regulates actin polymerization and cell migration in T lymphocytes.

    PubMed

    Vicente-Manzanares, Miguel; Rey, Mercedes; Pérez-Martínez, Manuel; Yáñez-Mó, María; Sancho, David; Cabrero, José Román; Barreiro, Olga; de la Fuente, Hortensia; Itoh, Kazuyuki; Sánchez-Madrid, Francisco

    2003-07-15

    Regulation of actin polymerization is critical for many different functions of T lymphocytes, including cell migration. Here we show that the RhoA effector mDia is induced in vitro in activated PBL and is highly expressed in vivo in diseased tissue-infiltrating activated lymphocytes. mDia localizes at the leading edge of polarized T lymphoblasts in an area immediately posterior to the leading lamella, in which its effector protein profilin is also concentrated. Overexpression of an activated mutant of mDia results in an inhibition of both spontaneous and chemokine-directed T cell motility. mDia does not regulate the shape of the cell, which involves another RhoA effector, p160 Rho-coiled coil kinase, and is not involved in integrin-mediated cell adhesion. However, mDia activation blocked CD3- and PMA-mediated cell spreading. mDia activation increased polymerized actin levels, which resulted in the blockade of chemokine-induced actin polymerization by depletion of monomeric actin. Moreover, mDia was shown to regulate the function of the small GTPase Rac1 through the control of actin availability. Together, our data demonstrate that RhoA is involved in the control of the filamentous actin/monomeric actin balance through mDia, and that this balance is critical for T cell responses.

  18. Maternal immune activation by LPS selectively alters specific gene expression profiles of interneuron migration and oxidative stress in the fetus without triggering a fetal immune response

    PubMed Central

    Oskvig, Devon B.; Elkahloun, Abdel G.; Johnson, Kory R.; Phillips, Terry M.; Herkenham, Miles

    2012-01-01

    Maternal immune activation (MIA) is a risk factor for the development of schizophrenia and autism. Infections during pregnancy activate the mother’s immune system and alter the fetal environment, with consequential effects on CNS function and behavior in the offspring, but the cellular and molecular links between infection-induced altered fetal development and risk for neuropsychiatric disorders are unknown. We investigated the immunological, molecular, and behavioral effects of MIA in the offspring of pregnant Sprague-Dawley rats given an intraperitoneal (0.25 mg/kg) injection of lipopolysaccharide (LPS) on gestational day 15. LPS significantly elevated pro-inflammatory cytokine levels in maternal serum, amniotic fluid, and fetal brain at 4 h, and levels decreased but remained elevated at 24 h. Offspring born to LPS-treated dams exhibited reduced social preference and exploration behaviors as juveniles and young adults. Whole genome microarray analysis of the fetal brain at 4 h post maternal LPS was performed to elucidate the possible molecular mechanisms by which MIA affects the fetal brain. We observed dysregulation of 3,285 genes in restricted functional categories, with increased mRNA expression of cellular stress and cell death genes and reduced expression of developmentally-regulated and brain-specific genes, specifically those that regulate neuronal migration of GABAergic interneurons, including the Distal-less (Dlx) family of transcription factors required for tangential migration from progenitor pools within the ganglionic eminences into the cerebral cortex. Our results provide a novel mechanism by which MIA induces the widespread down-regulation of critical neurodevelopmental genes, including those previously associated with autism. PMID:22310921

  19. Maternal immune activation by LPS selectively alters specific gene expression profiles of interneuron migration and oxidative stress in the fetus without triggering a fetal immune response.

    PubMed

    Oskvig, Devon B; Elkahloun, Abdel G; Johnson, Kory R; Phillips, Terry M; Herkenham, Miles

    2012-05-01

    Maternal immune activation (MIA) is a risk factor for the development of schizophrenia and autism. Infections during pregnancy activate the mother's immune system and alter the fetal environment, with consequential effects on CNS function and behavior in the offspring, but the cellular and molecular links between infection-induced altered fetal development and risk for neuropsychiatric disorders are unknown. We investigated the immunological, molecular, and behavioral effects of MIA in the offspring of pregnant Sprague-Dawley rats given an intraperitoneal (0.25 mg/kg) injection of lipopolysaccharide (LPS) on gestational day 15. LPS significantly elevated pro-inflammatory cytokine levels in maternal serum, amniotic fluid, and fetal brain at 4 h, and levels decreased but remained elevated at 24 h. Offspring born to LPS-treated dams exhibited reduced social preference and exploration behaviors as juveniles and young adults. Whole genome microarray analysis of the fetal brain at 4 h post maternal LPS was performed to elucidate the possible molecular mechanisms by which MIA affects the fetal brain. We observed dysregulation of 3285 genes in restricted functional categories, with increased mRNA expression of cellular stress and cell death genes and reduced expression of developmentally-regulated and brain-specific genes, specifically those that regulate neuronal migration of GABAergic interneurons, including the Distal-less (Dlx) family of transcription factors required for tangential migration from progenitor pools within the ganglionic eminences into the cerebral cortex. Our results provide a novel mechanism by which MIA induces the widespread down-regulation of critical neurodevelopmental genes, including those previously associated with autism.

  20. Ellagic Acid, a Dietary Polyphenol, Inhibits Tautomerase Activity of Human Macrophage Migration Inhibitory Factor and Its Pro-inflammatory Responses in Human Peripheral Blood Mononuclear Cells.

    PubMed

    Sarkar, Souvik; Siddiqui, Asim A; Mazumder, Somnath; De, Rudranil; Saha, Shubhra J; Banerjee, Chinmoy; Iqbal, Mohd S; Adhikari, Susanta; Alam, Athar; Roy, Siddhartha; Bandyopadhyay, Uday

    2015-05-27

    Ellagic acid (EA), a phenolic lactone, inhibited tautomerase activity of human macrophage migration inhibitory factor (MIF) noncompetitively (Ki = 1.97 ± 0.7 μM). The binding of EA to MIF was determined by following the quenching of tryptophan fluorescence. We synthesized several EA derivatives, and their structure-activity relationship studies indicated that the planar conjugated lactone moiety of EA was essential for MIF inhibition. MIF induces nuclear translocation of NF-κB and chemotaxis of peripheral blood mononuclear cells (PBMCs) to promote inflammation. We were interested in evaluating the effect of EA on nuclear translocation of NF-κB and chemotactic activity in human PBMCs in the presence of MIF. The results showed that EA inhibited MIF-induced NF-κB nuclear translocation in PBMCs, as evident from confocal immunofluorescence microscopic data. EA also inhibited MIF-mediated chemotaxis of PBMCs. Thus, we report MIF-inhibitory activity of EA and inhibition of MIF-mediated proinflammatory responses in PBMCs by EA.

  1. High concentration of branched-chain amino acids promotes oxidative stress, inflammation and migration of human peripheral blood mononuclear cells via mTORC1 activation.

    PubMed

    Zhenyukh, Olha; Civantos, Esther; Ruiz-Ortega, Marta; Sánchez, Maria Soledad; Vázquez, Clotilde; Peiró, Concepción; Egido, Jesús; Mas, Sebastián

    2017-03-01

    Leucine, isoleucine and valine are essential aminoacids termed branched-chain amino acids (BCAA) due to its aliphatic side-chain. In several pathological and physiological conditions increased BCAA plasma concentrations have been described. Elevated BCAA levels predict insulin resistance development. Moreover, BCAA levels higher than 2mmol/L are neurotoxic by inducing microglial activation in maple syrup urine disease. However, there are no studies about the direct effects of BCAA in circulating cells. We have explored whether BCAA could promote oxidative stress and pro-inflammatory status in peripheral blood mononuclear cells (PBMCs) obtained from healthy donors. In cultured PBMCs, 10mmol/L BCAA increased the production of reactive oxygen species (ROS) via both NADPH oxidase and the mitochondria, and activated Akt-mTOR signalling. By using several inhibitors and activators of these molecular pathways we have described that mTOR activation by BCAA is linked to ROS production and mitochondrial dysfunction. BCAA stimulated the activation of the redox-sensitive transcription factor NF-κB, which resulted in the release of pro-inflammatory molecules, such as interleukin-6, tumor necrosis factor-α, intracellular adhesion molecule-1 or CD40L, and the migration of PBMCs. In conclusion, elevated BCAA blood levels can promote the activation of circulating PBMCs, by a mechanism that involving ROS production and NF-κB pathway activation. These data suggest that high concentrations of BCAA could exert deleterious effects on circulating blood cells and therefore contribute to the pro-inflammatory and oxidative status observed in several pathophysiological conditions.

  2. Saussurea lappa Clarke-Derived Costunolide Prevents TNF α -Induced Breast Cancer Cell Migration and Invasion by Inhibiting NF- κ B Activity.

    PubMed

    Choi, Youn Kyung; Cho, Sung-Gook; Woo, Sang-Mi; Yun, Yee Jin; Jo, Jeakyung; Kim, Wooyoung; Shin, Yong Cheol; Ko, Seong-Gyu

    2013-01-01

    Saussurea lappa Clarke (SLC) has been used as a traditional medicine in Korea, China, and Japan for the treatment of abdominal pain and tenesmus. Costunolide, a sesquiterpene lactone isolated from SLC, has diverse medicinal effects. However, the anticancer effects of costunolide are still unclear in breast cancer. In this study, we demonstrate that costunolide suppresses tumor growth and metastases of MDA-MB-231 highly metastatic human breast cancer cells via inhibiting TNFα-induced NF-κB activation. Costunolide inhibited MDA-MB-231 tumor growth and metastases without affecting body weights in the in vivo mouse orthotopic tumor growth assays. In addition, costunolide inhibited in vitro TNFα-induced invasion and migration of MDA-MB-231 cells. Costunolide further suppressed TNFα-induced NF-κB signaling activation, resulting in a reduced expression of MMP-9, a well-known NF-κB-dependent gene to mediate breast cancer cell growth and metastases. Therefore, we conclude that SLC and its derivative costunolide suppress breast cancer growth and metastases by inhibiting TNFα-induced NF-κB activation, suggesting that costunolide as well as SLC may be promising anticancer drugs, especially for metastatic breast cancer.

  3. Long non-coding RNA CCAT1 that can be activated by c-Myc promotes pancreatic cancer cell proliferation and migration

    PubMed Central

    Yu, Qiuyun; Zhou, Xinfeng; Xia, Qing; Shen, Jia; Yan, Jia; Zhu, Jiuting; Li, Xiang; Shu, Ming

    2016-01-01

    This study aimed to investigate the potential role of lncRNA CCAT1 in the progression of pancreatic cancer (PC) and to reveal its possible molecular mechanism. The expression of CCAT1 was analyzed in PC tissues and their adjacent normal tissues from patients diagnosed with PC and in two pancreas cancer cell lines, namely PANC-1 and Aspc-1 using real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. The effects of CCAT1 expression on cell proliferation, cell cycle, and migration were analyzed using MTT assay, flow cytometry, and transwell assay, respectively. The effects of c-Myc expression on the expression of CCAT1 and E-box were also analyzed using RNA immunoprecipitation (RIP) and chromatin immunoprecipitation (ChIP) assays, respectively. The results showed that CCAT1 was highly expressed in PC tissues compared to the adjacent tissues (P<0.01) and was also overexpressed in PANC-1 and Aspc-1 cells (P<0.05). The silencing of CCAT1 significantly inhibited cell proliferation and migration (P<0.05), arrested cell cycle at G0/G1 stage, and decreased cyclin D1 expression (P<0.05). An increased expression of c-Myc was observed in the PC tissues compared to the adjacent tissues. We found that suppression of c-Myc altered CCAT1 expression by targeting its promoter at E-box. This study demonstrated that c-Myc-activated CCAT1 may contribute to tumorigenesis and metastasis of PC, which may serve as a potential target for the therapy of PC. PMID:28078015

  4. Stichopus japonicus Polysaccharide, Fucoidan, or Heparin Enhanced the SDF-1α/CXCR4 Axis and Promoted NSC Migration via Activation of the PI3K/Akt/FOXO3a Signaling Pathway.

    PubMed

    Cui, Chao; Wang, Peng; Cui, Ningshan; Song, Shuliang; Liang, Hao; Ji, Aiguo

    2016-11-01

    Stichopus japonicus Polysaccharide (SJP) is a sulfated polysaccharide from the body wall of the sea cucumber, Stichopus japonicus. Fucoidan is a heparinoid compound that belongs to a family of sulfated polyfucose polysaccharides. Heparin is a glycosaminoglycan. SJP, fucoidan, and heparin profoundly promoted stromal cell-derived factor 1 alpha (SDF-1α)-induced neural stem cell (NSC) migration in a concentration-dependent manner. In addition, the basal migration capacity of cells was significantly promoted after incubation with SJP, fucoidan, or heparin. Interaction of SJP, fucoidan, or heparin with SDF-1α efficiently showed additive effects on the promotion of cell migration from the neurosphere. SJP, fucoidan, or heparin interaction with SDF-1α treatment could increase Nestin expression. SDF-1α modulated by SJP, fucoidan, or heparin activated the CXCR4 receptor and directed cellular migration via the activation of the PI3K/Akt/FOXO3a signaling pathway. Moreover, interaction of SJP, fucoidan, or heparin with SDF-1α effectively promoted NSC migration and induced SDF-1α and CXCR4 expressions. Results suggested that SJP, fucoidan, and heparin might be good candidates for alleviating injury-initiated signals to which NSCs respond.

  5. The geography of Bangladeshi migration to Rome.

    PubMed

    Knights, M; King, R

    1998-12-01

    "With reference to the Bangladeshi community in Rome, this paper provides some answers to three key geographical questions: what is the migrants' regional pattern of origin in their home country; what are the mechanisms and routes of their migration to Italy; how are they spatially distributed in Rome?... Chain migration links specific origins in Bangladesh with spatial clusters and economic activities in Rome; the key here is the role of Bangladeshi community leaders in Rome who act both as migration sponsors and entrepreneurs."

  6. The Afa/Dr adhesins of diffusely adhering Escherichia coli stimulate interleukin-8 secretion, activate mitogen-activated protein kinases, and promote polymorphonuclear transepithelial migration in T84 polarized epithelial cells.

    PubMed

    Bétis, Fréderic; Brest, Patrick; Hofman, Véronique; Guignot, Julie; Bernet-Camard, Marie-Françoise; Rossi, Bernard; Servin, Alain; Hofman, Paul

    2003-03-01

    Afa/Dr diffusely adhering Escherichia coli (Afa/Dr DAEC) strains cause symptomatic urinary tract and intestinal infections. The proinflammatory effects of Afa/Dr DAEC strains in vitro have been not investigated to date. In the present study, we used confluent polarized monolayers of intestinal cell line T84 to evaluate the consequences of epithelial infection by Afa/Dr DAEC strains in terms of proinflammatory response. Polymorphonuclear leukocyte (PMNL) migration across the epithelial barrier was induced after incubation of the T84 monolayers with the wild-type Afa/Dr DAEC strain C1845 harboring the fimbrial F1845 adhesin and strain IH11128 harboring the Dr hemagglutinin, and the E. coli laboratory strain HB101 was transformed with the pSSS1 plasmid, producing Afa/Dr F1845 adhesin. PMNL migrations were correlated with a basolateral secretion of interleukin-8 by T84 cells and were abolished after incubation of epithelial cells with an anti-decay accelerating factor (DAF) antibody that recognized the short consensus repeat 3 domain of DAF (monoclonal antibody 1H4). Moreover, Afa/Dr DAEC strains induced tyrosine phosphorylation of several T84 proteins and activated the mitogen-activated protein kinases (ERK1/2 mitogen-activated protein, P38, and Jun-C kinases). These data demonstrated for the first time that, in vitro, Afa/Dr DAEC strains exert a proinflammatory signal in intestinal epithelial cells.

  7. Palmitoylethanolamide induces microglia changes associated with increased migration and phagocytic activity: involvement of the CB2 receptor.

    PubMed

    Guida, F; Luongo, L; Boccella, S; Giordano, M E; Romano, R; Bellini, G; Manzo, I; Furiano, A; Rizzo, A; Imperatore, R; Iannotti, F A; D'Aniello, E; Piscitelli, F; Sca Rossi, F; Cristino, L; Di Marzo, V; de Novellis, V; Maione, S

    2017-03-23

    The endogenous fatty acid amide palmitoylethanolamide (PEA) has been shown to exert anti-inflammatory actions mainly through inhibition of the release of pro-inflammatory molecules from mast cells, monocytes and macrophages. Indirect activation of the endocannabinoid (eCB) system is among the several mechanisms of action that have been proposed to underlie the different effects of PEA in vivo. In this study, we used cultured rat microglia and human macrophages to evaluate whether PEA affects eCB signaling. PEA was found to increase CB2 mRNA and protein expression through peroxisome proliferator-activated receptor-α (PPAR-α) activation. This novel gene regulation mechanism was demonstrated through: (i) pharmacological PPAR-α manipulation, (ii) PPAR-α mRNA silencing, (iii) chromatin immunoprecipitation. Moreover, exposure to PEA induced morphological changes associated with a reactive microglial phenotype, including increased phagocytosis and migratory activity. Our findings suggest indirect regulation of microglial CB2R expression as a new possible mechanism underlying the effects of PEA. PEA can be explored as a useful tool for preventing/treating the symptoms associated with neuroinflammation in CNS disorders.

  8. Inflammatory Levels of Nitric Oxide Inhibit Airway Epithelial Cell Migration by Inhibition of the Kinase ERK1/2 and Activation of Hypoxia-inducible Factor-1α*S⃞

    PubMed Central

    Bove, Peter F.; Hristova, Milena; Wesley, Umadevi V.; Olson, Nels; Lounsbury, Karen M.; van der Vliet, Albert

    2008-01-01

    Increased synthesis of NO during airway inflammation, caused by induction of nitric-oxide synthase 2 in several lung cell types, may contribute to epithelial injury and permeability. To investigate the consequence of elevated NO production on epithelial function, we exposed cultured monolayers of human bronchial epithelial cells to the NO donor diethylenetriaamine NONOate. At concentrations generating high nanomolar levels of NO, representative of inflammatory conditions, diethylenetriaamine NONOate markedly reduced wound closure in an in vitro scratch injury model, primarily by inhibiting epithelial cell migration. Analysis of signaling pathways and gene expression profiles indicated a rapid induction of the mitogen-activated protein kinase phosphatase (MPK)-1 and decrease in extracellular signal-regulated kinase (ERK)1/2 activation, as well as marked stabilization of hypoxia-inducible factor (HIF)-1α and activation of hypoxia-responsive genes, under these conditions. Inhibition of ERK1/2 signaling using U0126 enhanced HIF-1α stabilization, implicating ERK1/2 dephosphorylation as a contributing mechanism in NO-mediated HIF-1α activation. Activation of HIF-1α by the hypoxia mimic cobalt chloride, or cell transfection with a degradation-resistant HIF-1α mutant construct inhibited epithelial wound repair, implicating HIF-1α in NO-mediated inhibition of cell migration. Conversely, NO-mediated inhibition of epithelial wound closure was largely prevented after small interfering RNA suppression of HIF-1α. Finally, NO-mediated inhibition of cell migration was associated with HIF-1α-dependent induction of PAI-1 and activation of p53, both negative regulators of epithelial cell migration. Collectively, our results demonstrate that inflammatory levels of NO inhibit epithelial cell migration, because of suppression of ERK1/2 signaling, and activation of HIF-1α and p53, with potential consequences for epithelial repair and remodeling during airway inflammation. PMID

  9. The receptor for urokinase-plasminogen activator (uPAR) controls plasticity of cancer cell movement in mesenchymal and amoeboid migration style

    PubMed Central

    Taddei, Maria Letizia; Giannoni, Elisa; Laurenzana, Anna; Biagioni, Alessio; Chillà, Anastasia; Chiarugi, Paola; Fibbi, Gabriella; Rosso1, Mario Del

    2014-01-01

    The receptor for the urokinase plasminogen activator (uPAR) is up-regulated in malignant tumors. Historically the function of uPAR in cancer cell invasion is strictly related to its property to promote uPA-dependent proteolysis of extracellular matrix and to open a path to malignant cells. These features are typical of mesenchymal motility. Here we show that the full-length form of uPAR is required when prostate and melanoma cancer cells convert their migration style from the “path generating” mesenchymal to the “path finding” amoeboid one, thus conferring a plasticity to tumor cell invasiveness across three-dimensional matrices. Indeed, in response to a protease inhibitors-rich milieu, prostate and melanoma cells activated an amoeboid invasion program connoted by retraction of cell protrusions, RhoA-mediated rounding of the cell body, formation of a cortical ring of actin and a reduction of Rac-1 activation. While the mesenchymal movement was reduced upon silencing of uPAR expression, the amoeboid one was almost completely abolished, in parallel with a deregulation of small Rho-GTPases activity. In melanoma and prostate cancer cells we have shown uPAR colocalization with β1/β3 integrins and actin cytoskeleton, as well integrins-actin co-localization under both mesenchymal and amoeboid conditions. Such co-localizations were lost upon treatment of cells with a peptide that inhibits uPAR-integrin interactions. Similarly to uPAR silencing, the peptide reduced mesenchymal invasion and almost abolished the amoeboid one. These results indicate that full-length uPAR bridges the mesenchymal and amoeboid style of movement by an inward-oriented activity based on its property to promote integrin-actin interactions and the following cytoskeleton assembly. PMID:24681666

  10. Protein kinase A and regulation of neonatal Nav1.5 expression in human breast cancer cells: activity-dependent positive feedback and cellular migration.

    PubMed

    Chioni, Athina-Myrto; Shao, Dongmin; Grose, Richard; Djamgoz, Mustafa B A

    2010-02-01

    Voltage-gated Na(+) channels (VGSCs) are expressed in excitable cells (e.g. neurons and muscles), as well as in some classically 'non-excitable' cells (e.g. fibroblasts), and in carcinomas. In general, functional expression of VGSCs in plasma membrane (PM) is hierarchical and dynamic. Previously, we have shown that an activity-dependent positive feedback mechanism involving cAMP-dependent protein kinase A (PKA) plays a significant role in upregulation of VGSCs in strongly metastatic rat prostate cancer Mat-LyLu cells expressing Nav1.7. Here, we investigated the possible role of PKA in VGSC regulation and its functional consequences in strongly metastatic human breast cancer (BCa) MDA-MB-231 cells, where the neonatal splice form of Nav1.5 (nNav1.5) is the predominant VGSC present. Treatment with the PKA activator forskolin for 24h increased mRNA and PM protein levels of nNav1.5, without changing the total VGSC protein level. Opposite effects were obtained by application of the PKA inhibitor KT5720 or the highly specific VGSC blocker tetrodotoxin (TTX), the latter implying activity-dependent upregulation. We tested the possibility, therefore, that the activity dependence of VGSC (nNav1.5) expression involved PKA. Indeed, TTX pretreatment reduced the level of phosphorylated PKA and eliminated basal and PKA-stimulated cellular migration. These data suggested that activity-dependent positive feedback mediated by PKA plays an important role in the functional expression of nNav1.5 in BCa, and in turn, this enhances the cells' metastatic potential.

  11. S100B Protein Regulates Astrocyte Shape and Migration via Interaction with Src Kinase: IMPLICATIONS FOR ASTROCYTE DEVELOPMENT, ACTIVATION, AND TUMOR GROWTH.

    PubMed

    Brozzi, Flora; Arcuri, Cataldo; Giambanco, Ileana; Donato, Rosario

    2009-03-27

    S100B is a Ca(2+)-binding protein of the EF-hand type that is abundantly expressed in astrocytes and has been implicated in the regulation of several intracellular activities, including proliferation and differentiation. We show here that reducing S100B levels in the astrocytoma cell line GL15 and the Müller cell line MIO-M1 by small interference RNA technique results in a rapid disassembly of stress fibers, collapse of F-actin onto the plasma membrane and reduced migration, and acquisition of a stellate shape. Also, S100B-silenced GL15 and MIO-M1 Müller cells show a higher abundance of glial fibrillary acidic protein filaments, which mark differentiated astrocytes, compared with control cells. These effects are dependent on reduced activation of the phosphatidylinositol 3-kinase (PI3K) downstream effectors, Akt and RhoA, and consequently elevated activity of GSK3beta and Rac1 and decreased activity of the RhoA-associated kinase. Also, rat primary astrocytes transiently down-regulate S100B expression when exposed to the differentiating agent dibutyryl cyclic AMP and re-express S100B at later stages of dibutyryl cyclic AMP-induced differentiation. Moreover, reducing S100B levels results in a remarkably slow resumption of S100B expression, suggesting the S100B might regulate its own expression. Finally, we show that S100B interacts with Src kinase, thereby stimulating the PI3K/Akt and PI3K/RhoA pathways. These results suggest that S100B might contribute to reduce the differentiation potential of cells of the astrocytic lineage and participate in the astrocyte activation process in the case of brain insult and in invasive properties of glioma cells.

  12. Aloe emodin inhibits colon cancer cell migration/angiogenesis by downregulating MMP-2/9, RhoB and VEGF via reduced DNA binding activity of NF-κB.

    PubMed

    Suboj, Priya; Babykutty, Suboj; Valiyaparambil Gopi, Deepak Roshan; Nair, Rakesh S; Srinivas, Priya; Gopala, Srinivas

    2012-04-11

    Aloe emodin (AE), a natural anthraquinone, is reported to have antiproliferative activity in various cancer cell lines. In this study we analyzed molecular mechanisms involved in the antimigratory and antiangiogenic activity of this hydroxy anthraquinone in colon cancer cell, WiDr. Our results show that a relatively non toxic concentration of AE suppressed the phorbol-12-myristyl-13-acetate (PMA) induced migration and invasion of tumor cells. On analysis for the molecules involved in the migration/invasion, we found AE downregulated mRNA expression and promoter/gelatinolytic activity of Matrix Metalloproteinase (MMP)-2/9, as well as the RhoB expression at gene and protein level. It was also a strong inhibitor of Vascular Endothelial Growth Factor (VEGF) expression, promoter activity and endothelial cell migration/invasion and in vitro angiogenesis. AE suppressed the nuclear translocation and DNA binding of NF-κB, which is an important transcription factor for controlling MMP-2/9 and VEGF gene expression. Taken together these data indicate that AE target multiple molecules responsible for cellular invasion, migration and angiogenesis. Inhibitory effect on angiogenic and metastatic regulatory processes make AE a sensible candidate as a specific blocker of tumor associated events.

  13. Activated T cell trans-endothelial migration relies on myosin-IIA contractility for squeezing the cell nucleus through endothelial cell barriers.

    PubMed

    Jacobelli, Jordan; Estin Matthews, Miriam; Chen, Stephanie; Krummel, Matthew F

    2013-01-01

    Following activation, T cells are released from lymph nodes to traffic via the blood to effector sites. The re-entry of these activated T cells into tissues represents a critical step for them to carry out local effector functions. Here we have assessed defects in effector T cells that are acutely depleted in Myosin-IIA (MyoIIA) and show a T cell intrinsic requirement for this motor to facilitate the diapedesis step of extravasation. We show that MyoIIA accumulates at the rear of T cells undergoing trans-endothelial migration. T cells can extend protrusions and project a substantial portion of their cytoplasm through the endothelial wall in the absence of MyoIIA. However, this motor protein plays a crucial role in allowing T cells to complete the movement of their relatively rigid nucleus through the endothelial junctions. In vivo, this defect manifests as poor entry into lymph nodes, tumors and into the spinal cord, during tissue-specific autoimmunity, but not the spleen. This suggests that therapeutic targeting of this molecule may allow for differential attenuation of tissue-specific inflammatory responses.

  14. Activation of the cholinergic anti-inflammatory system by nicotine attenuates arthritis via suppression of macrophage migration

    PubMed Central

    Li, Sha; Zhou, Bin; Liu, Ben; Zhou, Yaou; Zhang, Huali; Li, Tong; Zuo, Xiaoxia

    2016-01-01

    Activation of the cholinergic anti-inflammatory pathway (CAP), which relies on the alpha-7 nicotinic acetylcholine receptor, has been reported to reduce proinflammatory cytokine levels in experimental arthritis. To gain more insight regarding the role of the CAP in the pathogenesis of arthritis, the present study focused on the modulation of macrophage infiltration. In a mouse model of collagen-induced arthritis (CIA), nicotine and vagotomy were used to stimulate and inhibit the CAP, respectively. Subsequently, arthritic scores were measured and histopathological assessment of joint sections was conducted. Cluster of differentiation (CD)11b-positive macrophages in the synovium were studied by immunofluorescence histochemistry. The serum levels of chemokines, including macrophage inflammatory protein (MIP)-1α, monocyte chemoattractant protein (MCP)-1 and MIP-2 were evaluated by ELISA. Furthermore, the expression levels of C-C chemokine receptor (CCR)2 and intercellular adhesion molecule (ICAM)-1 in the synovium were evaluated by immunohistochemical staining. The results indicated that treatment with nicotine significantly attenuated the clinical and histopathological changes associated with arthritis, reduced CD11b-positive macrophages in the synovium, and downregulated the serum expression levels of MIP-1α and MCP-1. Conversely, vagotomy aggravated arthritis and upregulated the expression levels of MCP-1. However, MIP-2 expression did not differ among the control, CIA, vagotomy and nicotine groups. In addition, the expression levels of CCR2 were reduced in the nicotine group; however, they were increased in the vagotomy group compared with in the untreated CIA group. The expression levels of ICAM-1 in the synovium were also influenced by activation of the CAP. Taken together, the present results indicated that nicotine-induced activation of the CAP in mice with CIA may reduce the number of macrophages in the synovium, which may serve a role in alleviating

  15. Nuclear factor of activated T cells c1 mediates p21-activated kinase 1 activation in the modulation of chemokine-induced human aortic smooth muscle cell F-actin stress fiber formation, migration, and proliferation and injury-induced vascular wall remodeling.

    PubMed

    Kundumani-Sridharan, Venkatesh; Singh, Nikhlesh K; Kumar, Sanjay; Gadepalli, Ravisekhar; Rao, Gadiparthi N

    2013-07-26

    Recent literature suggests that cyclin-dependent kinases (CDKs) mediate cell migration. However, the mechanisms were not known. Therefore, the objective of this study is to test whether cyclin/CDKs activate Pak1, an effector of Rac1, whose involvement in the modulation of cell migration and proliferation is well established. Monocyte chemotactic protein 1 (MCP1) induced Pak1 phosphorylation/activation in human aortic smooth muscle cells (HASMCs) in a delayed time-dependent manner. MCP1 also stimulated F-actin stress fiber formation in a delayed manner in HASMCs, as well as the migration and proliferation of these cells. Inhibition of Pak1 suppressed MCP1-induced HASMC F-actin stress fiber formation, migration, and proliferation. MCP1 induced cyclin D1 expression as well as CDK6 and CDK4 activities, and these effects were dependent on activation of NFATc1. Depletion of NFATc1, cyclin D1, CDK6, or CDK4 levels attenuated MCP1-induced Pak1 phosphorylation/activation and resulted in decreased HASMC F-actin stress fiber formation, migration, and proliferation. CDK4, which appeared to be activated downstream of CDK6, formed a complex with Pak1 in response to MCP1. MCP1 also activated Rac1 in a time-dependent manner, and depletion/inhibition of its levels/activation abrogated MCP1-induced NFATc1-cyclin D1-CDK6-CDK4-Pak1 signaling and, thereby, decreased HASMC F-actin stress fiber formation, migration, and proliferation. In addition, smooth muscle-specific deletion of NFATc1 led to decreased cyclin D1 expression and CDK6, CDK4, and Pak1 activities, resulting in reduced neointima formation in response to injury. Thus, these observations reveal that Pak1 is a downstream effector of CDK4 and Rac1-dependent, NFATc1-mediated cyclin D1 expression and CDK6 activity mediate this effect. In addition, smooth muscle-specific deletion of NFATc1 prevented the capacity of vascular smooth muscle cells for MCP-1-induced activation of the cyclin D1-CDK6-CDK4-Pak1 signaling axis, affecting

  16. The splicing activator DAZAP1 integrates splicing control into MEK/Erk-regulated cell proliferation and migration

    NASA Astrophysics Data System (ADS)

    Choudhury, Rajarshi; Roy, Sreerupa Ghose; Tsai, Yihsuan S.; Tripathy, Ashutosh; Graves, Lee M.; Wang, Zefeng

    2014-01-01

    Alternative splicing of pre-messenger RNA (mRNA) is a critical stage of gene regulation in response to environmental stimuli. Here we show that DAZAP1, an RNA-binding protein involved in mammalian development and spermatogenesis, promotes inclusion of weak exons through specific recognition of diverse cis-elements. The carboxy-terminal proline-rich domain of DAZAP1 interacts with and neutralizes general splicing inhibitors, and is sufficient to activate splicing when recruited to pre-mRNA. This domain is phosphorylated by the MEK/Erk (extracellular signal-regulated protein kinase) pathway and this modification is essential for the splicing regulatory activity and the nuclear/cytoplasmic translocation of DAZAP1. Using mRNA-seq, we identify endogenous splicing events regulated by DAZAP1, many of which are involved in maintaining cell growth. Knockdown or over-expression of DAZAP1 causes a cell proliferation defect. Taken together, these studies reveal a molecular mechanism that integrates splicing control into MEK/Erk-regulated cell proliferation.

  17. Characterization of Collective Cell Migration Dynamics

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  18. Multiscale Cues Drive Collective Cell Migration

    PubMed Central

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

    2016-01-01

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

  19. Multiscale Cues Drive Collective Cell Migration

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  20. Population, migration and urbanization.

    PubMed

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  1. Rho-directed forces in collective migration.

    PubMed

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

    2014-03-01

    Collective cell migration depends on multicellular mechanocoupling between leader and follower cells to coordinate traction force and position change. Co-registration of Rho GTPase activity and forces in migrating epithelial cell sheets now shows how RhoA controls leader-follower cell hierarchy, multicellular cytoskeletal contractility and mechanocoupling, to prevent ectopic leading edges and to move the cell sheet forward.

  2. [Circular migration in Indonesia].

    PubMed

    Mantra, I B

    1979-12-01

    The author examines circular migration in Indonesia, with primary focus on the 1970s. It is found that circular, or repeated return migration, generally occurs over short distances and for short periods and is more frequent than lifetime migration. The relationships between improvements in the national transport system, access to labor force opportunities in both the formal and informal sectors of the economy, and circular migration are discussed.

  3. More Myths of Migration.

    ERIC Educational Resources Information Center

    Basch, Linda; Lerner, Gail

    1986-01-01

    Challenges "myths" about women and migration, including (1) the causes of migration are economic, not racism; (2) migrant women receive support from feminist groups and trade unions; (3) transnational corporations are positive forces in developing nations; (4) migration today has little impact on family life; and (5) most migrants cluster in…

  4. Migration and Adult Education

    ERIC Educational Resources Information Center

    Gois, William

    2007-01-01

    The objective of this paper is to highlight the role of adult education as a tool in addressing labour migration issues, specifically those concerning the protection of migrant workers' rights and the transformation of the impact of migration into positive holistic developmental gains. The view of labour migration as a means to forge the economic…

  5. Activation of G-Protein-Coupled Estrogen Receptor Inhibits the Migration of Human Nonsmall Cell Lung Cancer Cells via IKK-β/NF-κB Signals.

    PubMed

    Zhu, Guangfa; Huang, Yan; Wu, Chunting; Wei, Dong; Shi, Yingxin

    2016-08-01

    Estrogen signals have been suggested to modulate the progression and metastasis of nonsmall cell lung cancer (NSCLC), which is one of the leading causes of cancer deaths worldwide. While there are limited data concerning the roles and effects of G-protein-coupled estrogen receptor (GPER) on the progression of NSCLC, our present study reveals that the expression of GPER in NSCLC cells is obviously greater than that in lung fibroblast cell line MRC-5. Activation of GPER via its specific agonist G-1 decreases the in vitro motility of A549 and H358 cells and the expression of matrix metalloproteinase 2 (MMP-2) and MMP-9. Further, G-1 treatment can rapidly decrease the phosphorylation, nuclear translocation, and promoter activities of NF-κB in NSCLC cells. BAY 11-7082, the inhibitor of NF-κB, also inhibits the expression of MMP-2/9, while overexpression of p65 significantly attenuates G-1-induced downregulation of MMP-2/9. It suggests that inhibition of NF-κB mediates G-1-induced MMP-2/9 downregulation. G-1 treatment significantly down regulates the phosphorylation of IκB kinase β (IKK-β) and IκBα, while not IKK-α, in both 549 and H358 cells. ACHP, the specific inhibitor of IKK-β, can reinforce G-1-induced MMP-2/9 downregulation and invasion suppression of A549 cells. Collectively, our results suggest that activation of GPER can inhibit the migration of human NSCLC cells via suppression of IKK-β/NF-κB signals. These findings will help to better understand the roles and mechanisms of GPER as a potential therapy target for NSCLC patients.

  6. Macrophage migration inhibitory factor promotes cardiac stem cell proliferation and endothelial differentiation through the activation of the PI3K/Akt/mTOR and AMPK pathways

    PubMed Central

    CUI, JINJIN; ZHANG, FENGYUN; WANG, YONGSHUN; LIU, JINGJIN; MING, XING; HOU, JINGBO; LV, BO; FANG, SHAOHONG; YU, BO

    2016-01-01

    Macrophage migration inhibitory factor (MIF) has pleiotropic immune functions in a number of inflammatory diseases. Recent evidence from expression and functional studies has indicated that MIF is involved in various aspects of cardiovascular disease. In this study, we aimed to determine whether MIF supports in vitro c-kit+CD45− cardiac stem cell (CSC) survival, proliferation and differentiation into endothelial cells, as well as the possible mechanisms involved. We observed MIF receptor (CD74) expression in mouse CSCs (mCSCs) using PCR and immunofluorescence staining, and MIF secretion by mCSCs using PCR and ELISA in vitro. Increasing amounts of exogenous MIF did not affect CD74 expression, but promoted mCSC survival, proliferation and endothelial differentiation. By contrast, treatment with an MIF inhibitor (ISO-1) or siRNA targeting CD74 (CD74-siRNA) suppressed the biological changes induced by MIF in the mCSCs. Increasing amounts of MIF increased the phosphorylation of Akt and mammalian target of rapamycin (mTOR), which are known to support cell survival, proliferation and differentiation. These effects of MIF on the mCSCs were abolished by LY294002 [a phosphoinositide 3-kinase (PI3K) inhibitor] and MK-2206 (an Akt inhibitor). Moreover, adenosine monophosphate-activated protein kinase (AMPK) phosphorylation increased following treatment with MIF. The AMPK inhibitor, compound C, partly blocked the pro-proliferative effects of MIF on the mCSCs. In conclusion, our results suggest that MIF promotes mCSC survival, proliferation and endothelial differentiation through the activation of the PI3K/Akt/mTOR and AMPK signaling pathways. Thus, MIF may prove to be a potential therapeutic factor in the treatment of heart failure and myocardial infarction by activating CSCs. PMID:27035848

  7. Biological activity and migration of wear particles in the knee joint: an in vivo comparison of six different polyethylene materials.

    PubMed

    Utzschneider, S; Lorber, V; Dedic, M; Paulus, A C; Schröder, C; Gottschalk, O; Schmitt-Sody, M; Jansson, V

    2014-06-01

    Wear of polyethylene causes loosening of joint prostheses because of the particle mediated activity of the host tissue. It was hypothesized that conventional and crosslinked polyethylene particles lead to similar biological effects around the knee joint in vivo as well as to a similar particle distribution in the surrounding tissues. To verify these hypotheses, particle suspensions of six different polyethylene materials were injected into knee joints of Balb/C mice and intravital microscopic, histological and immunohistochemical evaluations were done after 1 week. Whereas the biological effects on the synovial layer and the subchondral bone of femur and tibia were similar for all the polyethylenes, two crosslinked materials showed an elevated cytokine expression in the articular cartilage. Furthermore, the distribution of particles around the joint was dependent on the injected polyethylene material. Those crosslinked particles, which remained mainly in the joint space, showed an increased expression of TNF-alpha in articular cartilage. The data of this study support the use of crosslinked polyethylene in total knee arthroplasty. In contrast, the presence of certain crosslinked wear particles in the joint space can lead to an elevated inflammatory reaction in the remaining cartilage, which challenges the potential use of those crosslinked polyethylenes for unicondylar knee prostheses.

  8. COMP-angiopoietin 1 increases proliferation, differentiation, and migration of stem-like cells through Tie-2-mediated activation of p38 MAPK and PI3K/Akt signal transduction pathways

    SciTech Connect

    Kook, Sung-Ho; Lim, Shin-Saeng; Cho, Eui-Sic; Lee, Young-Hoon; Han, Seong-Kyu; Lee, Kyung-Yeol; Kwon, Jungkee; Hwang, Jae-Won; Bae, Cheol-Hyeon; Seo, Young-Kwon; Lee, Jeong-Chae

    2014-12-12

    Highlights: • COMP-Ang1 induces Tie-2 activation in BMMSCs, but not in primary osteoblasts. • Tie-2 knockdown inhibits COMP-Ang1-stimulated proliferation and osteoblastogenesis. • Tie-2 knockdown prevents COMP-Ang1-induced activation of PI3K/Akt and p38 MAPK. • COMP-Ang1 induces migration of cells via activation of PI3K/Akt and CXCR4 pathways. • COMP-Ang1 stimulates in vivo migration of PDLSCs into a calvarial defect site of rats. - Abstract: Recombinant COMP-Ang1, a chimera of angiopoietin-1 (Ang1) and a short coiled-coil domain of cartilage oligomeric matrix protein (COMP), is under consideration as a therapeutic agent capable of inducing the homing of cells with increased angiogenesis. However, the potentials of COMP-Ang1 to stimulate migration of mesenchymal stem cells (MSCs) and the associated mechanisms are not completely understood. We examined the potential of COMP-Ang1 on bone marrow (BM)-MSCs, human periodontal ligament stem cells (PDLSCs), and calvarial osteoblasts. COMP-Ang1 augmented Tie-2 induction at protein and mRNA levels and increased proliferation and expression of runt-related transcription factor 2 (Runx2), osterix, and CXCR4 in BMMSCs, but not in osteoblasts. The COMP-Ang1-mediated increases were inhibited by Tie-2 knockdown and by treating inhibitors of phosphoinositide 3-kinase (PI3K), LY294002, or p38 mitogen-activated protein kinase (MAPK), SB203580. Phosphorylation of p38 MAPK and Akt was prevented by siRNA-mediated silencing of Tie-2. COMP-Ang1 also induced in vitro migration of BMMSCs and PDLSCs. The induced migration was suppressed by Tie-2 knockdown and by CXCR4-specific peptide antagonist or LY294002, but not by SB203580. Furthermore, COMP-Ang1 stimulated the migration of PDLSCs into calvarial defect site of rats. Collectively, our results demonstrate that COMP-Ang1-stimulated proliferation, differentiation, and migration of progenitor cells may involve the Tie-2-mediated activation of p38 MAPK and PI3K/Akt pathways.

  9. SLITHER: a web server for generating contiguous conformations of substrate molecules entering into deep active sites of proteins or migrating through channels in membrane transporters.

    PubMed

    Lee, Po-Hsien; Kuo, Kuei-Ling; Chu, Pei-Ying; Liu, Eric M; Lin, Jung-Hsin

    2009-07-01

    Many proteins use a long channel to guide the substrate or ligand molecules into the well-defined active sites for catalytic reactions or for switching molecular states. In addition, substrates of membrane transporters can migrate to another side of cellular compartment by means of certain selective mechanisms. SLITHER (http://bioinfo.mc.ntu.edu.tw/slither/or http://slither.rcas.sinica.edu.tw/) is a web server that can generate contiguous conformations of a molecule along a curved tunnel inside a protein, and the binding free energy profile along the predicted channel pathway. SLITHER adopts an iterative docking scheme, which combines with a puddle-skimming procedure, i.e. repeatedly elevating the potential energies of the identified global minima, thereby determines the contiguous binding modes of substrates inside the protein. In contrast to some programs that are widely used to determine the geometric dimensions in the ion channels, SLITHER can be applied to predict whether a substrate molecule can crawl through an inner channel or a half-channel of proteins across surmountable energy barriers. Besides, SLITHER also provides the list of the pore-facing residues, which can be directly compared with many genetic diseases. Finally, the adjacent binding poses determined by SLITHER can also be used for fragment-based drug design.

  10. Pharmacological inhibition of p38 mitogen-activated protein kinases affects KC/CXCL1-induced intraluminal crawling, transendothelial migration, and chemotaxis of neutrophils in vivo.

    PubMed

    Xu, Najia; Hossain, Mokarram; Liu, Lixin

    2013-01-01

    p38 mitogen-activated protein kinase (MAPK) signalling is critical in the pathophysiology of a variety of inflammatory processes. Leukocyte recruitment to the site of inflammation is a multistep process governed by specific signalling cascades. After adhesion in the lumen, many leukocytes crawl to optimal sites at endothelial junctions and transmigrate to extravascular tissue in a Mac-1-dependent manner. The signalling mechanisms that regulate postadhesion steps of intraluminal crawling, transmigration, and chemotaxis in tissue remain incompletely understood. The present study explored the effect of p38 MAPK inhibitor SB203580 on various parameters of neutrophil recruitment triggered by chemokine KC (CXCL1) gradient. Neutrophil-endothelial interactions in microvasculature of murine cremaster muscle were determined using intravital microscopy and time-lapsed video analysis. SB203580 (100 nM) did not change leukocyte rolling but significantly attenuated neutrophil adhesion, emigration, and transmigration and impaired the initiation of neutrophil crawling and transmigration. In response to KC chemotactic gradient, SB203580 significantly reduced the velocity of migration and chemotaxis index of neutrophils in tissue. The upregulation of Mac-1 expression in neutrophils stimulated by KC was significantly blunted by SB203580 in vitro. Collectively, our findings demonstrate that pharmacological suppression of p38 MAPK significantly impairs multiple steps of neutrophil recruitment in vivo.

  11. C-terminal fragment of amebin promotes actin filament bundling, inhibits acto-myosin ATPase activity and is essential for amoeba migration.

    PubMed

    Jóźwiak, Jolanta; Rzhepetskyy, Yuriy; Sobczak, Magdalena; Kocik, Elżbieta; Skórzewski, Radosław; Kłopocka, Wanda; Rędowicz, Maria Jolanta

    2011-02-01

    Amebin [formerly termed as ApABP-FI; Sobczak et al. (2007) Biochem. Cell Biol. 85] is encoded in Amoeba proteus by two transcripts, 2672-nt and 1125-nt. A product of the shorter transcript (termed as C-amebin), comprising C-terminal 375 amino-acid-residue fragment of amebin, has been expressed and purified as the recombinant GST-fusion protein. GST-C-amebin bound both to monomeric and filamentous actin. The binding was Ca(2+)-independent and promoted filament bundling, as revealed with the transmission electron microscopy. GST-C-amebin significantly decreased MgATPase activity of rabbit skeletal muscle acto-S1. Removal with endoproteinase ArgC of a positively charged C-terminal region of GST-amebin containing KLASMWEQ sequence abolished actin-binding and bundling as well as the ATPase-inhibitory effect of C-amebin, indicating that this protein region was involved in the interaction with actin. Microinjection of amoebae with antibody against C-terminus of amebin significantly affected amoebae morphology, disturbed cell polarization and transport of cytoplasmic granules as well as blocked migration. These data indicate that amebin may be one of key regulators of the actin-cytoskeleton dynamics and actin-dependent motility in A. proteus.

  12. Magnolol suppresses metastasis via inhibition of invasion, migration, and matrix metalloproteinase-2/-9 activities in PC-3 human prostate carcinoma cells.

    PubMed

    Hwang, Eun-Sun; Park, Kwang-Kyun

    2010-01-01

    Magnolol, a hydroxylated biphenyl compound isolated from the root and stem bark of Magnolia officinalis, has been reported to have anticancer activity, but little is known about its molecular mechanisms of action. Increased expression of cyclooxygenase-2 (COX-2), a key enzyme in arachidonic acid metabolism, has been identified in many cancer types. Matrix metalloproteinases (MMPs) are enzymes involved in various steps of metastasis development. The objective of this study was to study the effects of magnolol on cancer invasion and metastasis using PC-3 human prostate carcinoma cells. Cellular proliferation was determined by MTT colorimetric assay. Magnolol inhibited cell growth in a dose-dependent manner. In an invasion assay conducted in Transwell chambers, magnolol showed 33 and 98% inhibition of cancer cell at 10 microM and 20 microM concentrations, respectively, compared to the control. The expression of MMP-2/-9 and COX-1/-2 was assessed by gelatin zymography and Western blot respectively. The protein and mRNA levels of both MMP-2 and MMP-9 were down-regulated by magnolol treatment in a dose-dependent manner. These results demonstrate the antimetastatic properties of magnolol in inhibiting the adhesion, invasion, and migration of PC-3 human prostate cancer cells.

  13. Dynamic activity of the filopodia of sea urchin embryonic cells and their role in directed migration of the primary mesenchyme in vitro.

    PubMed

    Karp, G C; Solursh, M

    1985-12-01

    Primary mesenchyme cells used in this study were isolated from Lytechinus pictus mesenchyme blastulae by their ability to preferentially adhere to the surface of a tissue culture dish in the presence of serum. Once isolated, primary mesenchyme cells were found to form thin, elongated, active filopodia which closely resemble the filopodia seen in vivo. The filopodia formed in vitro can move as stiffened bristles, bend gradually or very sharply, or be slowly withdrawn. The integrity of the filopodia is not affected by nocodazole but is totally disrupted by cytochalasin D. Filopodia exhibit several apparent functions in vitro: as organelles involved in contacting the external environment, as anchoring appendages that hold the cell bodies in place, and as intercellular connectives that can join cell bodies. The filopodia of primary mesenchyme cells appear to have similar roles within the embryo. The function of the filopodia has been explored by watching the behavior of isolated primary mesenchyme cells in close proximity to deposits of extracellular material (ECM) prepared from mesenchyme blastulae. When the filopodium from a mesenchyme cell makes contact with the nearby ECM, a response is initiated which causes the cell body to move in a directed manner toward the ECM deposit. The use of this type of response as a model system for the study of the migration of primary mesenchyme cells within the embryo is considered.

  14. Mechanisms of Leukocyte Transendothelial Migration

    PubMed Central

    Muller, William A.

    2013-01-01

    Neither the innate nor adaptive immune system “responds” unless leukocytes cross blood vessels. This process occurs through diapedesis, in which the leukocyte moves in an ameboid fashion through tightly apposed endothelial borders and, in some cases, through the endothelial cell itself. This review focuses on the active role of the endothelial cell in diapedesis. Several mechanisms play a critical role in transendothelial migration, including signals derived from clustering of apically disposed intercellular adhesion molecule 1 and vascular cell adhesion molecule 1, disruption or loosening of adherens junctions, and targeted recycling of platelet/endothelial cell adhesion molecule and other molecules from the recently described lateral border recycling compartment. Surprisingly, many of the same molecules and mechanisms that regulate paracellular migration also control transcellular migration. A hypothesis that integrates the various known mechanisms of transmigration is proposed. PMID:21073340

  15. Mechanisms of leukocyte transendothelial migration.

    PubMed

    Muller, William A

    2011-01-01

    Neither the innate nor adaptive immune system "responds" unless leukocytes cross blood vessels. This process occurs through diapedesis, in which the leukocyte moves in an ameboid fashion through tightly apposed endothelial borders and, in some cases, through the endothelial cell itself. This review focuses on the active role of the endothelial cell in diapedesis. Several mechanisms play a critical role in transendothelial migration, including signals derived from clustering of apically disposed intercellular adhesion molecule 1 and vascular cell adhesion molecule 1, disruption or loosening of adherens junctions, and targeted recycling of platelet/endothelial cell adhesion molecule and other molecules from the recently described lateral border recycling compartment. Surprisingly, many of the same molecules and mechanisms that regulate paracellular migration also control transcellular migration. A hypothesis that integrates the various known mechanisms of transmigration is proposed.

  16. [The theory of migration].

    PubMed

    Delbruck, C; Raffelhuschen, B

    1993-09-01

    "The present and expected migration flows in Europe require a detailed analysis of determinants and elements of migration decisions. This survey encompasses a view on classical--labor market and demand side oriented--theories, the more recent human capital approach as well as on migration under asymmetric information. Since these theories so far yield an unsatisfactory basis for description and forecasting of multilateral migration flows, a closer look at empirical methods of migration research is taken. Consequently, a description of possible policy oriented applications of the gravity model and the random utility approach, with their descriptive and normative characteristics, is given." (SUMMARY IN ENG)

  17. Adaxial cell migration in the zebrafish embryo is an active cell autonomous property that requires the Prdm1a transcription factor.

    PubMed

    Ono, Yosuke; Yu, Weimiao; Jackson, Harriet E; Parkin, Caroline A; Ingham, Philip W

    2015-01-01

    Adaxial cells, the progenitors of slow-twitch muscle fibres in zebrafish, exhibit a stereotypic migratory behaviour during somitogenesis. Although this process is known to be disrupted in various mutants, its precise nature has remained unclear. Here, using in vivo imaging and chimera analysis, we show that adaxial cell migration is a cell autonomous process, during which cells become polarised and extend filopodia at their leading edge. Loss of function of the Prdm1a transcription factor disrupts the polarisation and migration of adaxial cells, reflecting a role that is independent of its repression of sox6 expression. Expression of the M- and N-cadherins, previously implicated in driving adaxial cell migration, is largely unaffected by loss of Prdm1a function, suggesting that differential cadherin expression is not sufficient for adaxial cell migration.

  18. Analyzing bat migration

    USGS Publications Warehouse

    Cryan, Paul M.; Diehl, Robert H.

    2009-01-01

    T HE MIGRATORY MOVEIvl.ENTS OF BATS have proven ex­ tremely difficult to determine. Despite extensive efforts during the past century to track the movements of bats across landscapes, efficient methods of following small- to medium-size volant animals <240 gl for extended periods (>8 weeks) over long distances (>100 km) have not been developed. Important questions about bat migration remain unanswered: Which bats migrate? Where do they go? How far do they move? How high and fast do they fly? What are their habitat needs during migration? How do bats orient and navigate during migration? Addressing these apparently simple questions will be a considerable challenge to anyone interested in advancing the study of bat migration. In this chapter, we present direct and indirect methods used to study bat migration as well as techniques that have worked for studying bird migration that could feasibly be adapted to the study of bats.

  19. Seismic hydraulic fracture migration originated by successive deep magma pulses: The 2011-2013 seismic series associated to the volcanic activity of El Hierro Island

    NASA Astrophysics Data System (ADS)

    Díaz-Moreno, A.; Ibáñez, J. M.; De Angelis, S.; García-Yeguas, A.; Prudencio, J.; Morales, J.; Tuvè, T.; García, L.

    2015-11-01

    In this manuscript we present a new interpretation of the seismic series that accompanied eruptive activity off the coast of El Hierro, Canary Islands, during 2011-2013. We estimated temporal variations of the Gutenberg-Richter b value throughout the period of analysis, and performed high-precision relocations of the preeruptive and syneruptive seismicity using a realistic 3-D velocity model. Our results suggest that eruptive activity and the accompanying seismicity were caused by repeated injections of magma from the mantle into the lower crust. These magma pulses occurred within a small and well-defined volume resulting in the emplacement of fresh magma along the crust-mantle boundary underneath El Hierro. We analyzed the distribution of earthquake hypocenters in time and space in order to assess seismic diffusivity in the lower crust. Our results suggest that very high earthquake rates underneath El Hierro represent the response of a stable lower crust to stress perturbations with pulsatory character, linked to the injection of magma from the mantle. Magma input from depth caused large stress perturbations to propagate into the lower crust generating energetic seismic swarms. The absence of any preferential alignment in the spatial pattern of seismicity reinforces our hypothesis that stress perturbation and related seismicity, had diffusive character. We conclude that the temporal and spatial evolution of seismicity was neither tracking the path of magma migration nor it defines the boundaries of magma storage volumes such as a midcrustal sill. Our conceptual model considers pulsatory magma injection from the upper mantle and its propagation along the Moho. We suggest, within this framework, that the spatial and temporal distributions of earthquake hypocenters reflect hydraulic fracturing processes associated with stress propagation due to magma movement.

  20. Silver migration from silver-modified activated carbon applied as a water filtration medium in classic cartridges of jug filter systems.

    PubMed

    Garboś, S; Swięcicka, D

    2012-01-01

    A comprehensive study was undertaken in order to examine the possible adverse effect of jug filter systems (JFSs) on the quality of filtered water taking into account the released amounts of silver (Ag) into the filtered test water. Nine brands of JFSs (A-I) were investigated according to BS 8427:2004 using a validated ICP/MS method. Essential modification of BS 8427:2004 within the domain of the composite sample preparation was proposed and applied during the tests. The established grand mean concentrations of released Ag from A-H classic cartridges (containing Ag-modified activated carbon and ion exchange resins) and I classic cartridge (containing non-modified activated carbon and ion exchange resin) installed in corresponding JFSs were in the range of 2.6-13.1 µg l⁻¹ and lower than 0.014 µg l⁻¹, respectively. These values were applied for the estimation of the daily intakes of Ag connected with the consumption of water filtered using JFSs (ranging from < 0.0004 to 0.374 µg kg⁻¹ day⁻¹). After taking into account the grand mean concentrations of Ag established during the whole cycle of exploitation for nine JFSs and on the basis of available toxicological data for this element, no long-term risk for human health with respect to appearance of argyria (a condition caused by improper exposure to the Ag or Ag compounds) could be expected (the Hazard Quotient indices estimated as ratios of the daily intakes to the reference dose of Ag were equal or lower than 0.075). Ag-modified activated carbon is not included in the positive list of the authorised substances of the European Commission Regulation (EU) No. 10/2011. Additionally, this material has not been approved by European Food Safety Authority (EFSA). A part of water filtered by JFSs can be directly consumed as drinking water and additionally the remaining water can be applied for the preparation of food products (drinks, soups, etc.). In both cases the quality of water has to fulfil

  1. Mesenchymal Stromal Cells Prevent Allostimulation In Vivo and Control Checkpoints of Th1 Priming: Migration of Human DC to Lymph Nodes and NK Cell Activation.

    PubMed

    Consentius, C; Akyüz, L; Schmidt-Lucke, J A; Tschöpe, C; Pinzur, L; Ofir, R; Reinke, P; Volk, H-D; Juelke, K

    2015-10-01

    Although the immunomodulatory potency of mesenchymal stromal cells (MSC) is well established, the mechanisms behind are still not clear. The crosstalk between myeloid dendritic cells (mDC) and natural killer (NK) cells and especially NK cell-derived interferon-gamma (IFN-γ) play a pivotal role in the development of type 1 helper (Th1) cell immune responses. While many studies explored the isolated impact of MSC on either in vitro generated DC, NK, or T cells, there are only few data available on the complex interplay between these cells. Here, we investigated the impact of MSC on the functionality of human mDC and the consequences for NK cell and Th1 priming in vitro and in vivo. In critical limb ischemia patients, who have been treated with allogeneic placenta-derived mesenchymal-like stromal cells (PLX-PAD), no in vivo priming of Th1 responses toward the major histocompatibility complex (MHC) mismatches could be detected. Further in vitro studies revealed that mDC reprogramming could play a central role for these effects. Following crosstalk with MSC, activated mDC acquired a tolerogenic phenotype characterized by reduced migration toward CCR7 ligand and impaired ability to stimulate NK cell-derived IFN-γ production. These effects, which were strongly related to an altered interleukin (IL)-12/IL-10 production by mDC, were accompanied by an effective prevention of Th1 priming in vivo. Our findings provide novel evidence for the regulation of Th1 priming by MSC via modulation of mDC and NK cell crosstalk and show that off-the-shelf produced MHC-mismatched PLX-PAD can be used in patients without any sign of immunogenicity.

  2. Over-expression of TRIM37 promotes cell migration and metastasis in hepatocellular carcinoma by activating Wnt/β-catenin signaling

    SciTech Connect

    Jiang, Jianxin; Yu, Chao; Chen, Meiyuan; Tian, She; Sun, Chengyi

    2015-09-04

    Hepatocellular carcinoma (HCC) is the most common cancer in the world especially in East Asia and Africa. Advanced stage, metastasis and frequent relapse are responsible for the poor prognosis of HCC. However, the precise mechanisms underlying HCC remained unclear. So it is urgent to identify the pathological processes and relevant molecules of HCC. TRIM37 is an E3 ligase and has been observed deregulated expression in various tumors. Recent studies of TRIM37 have implicated that TRIM37 played critical roles in cell proliferation and other processes. In the present study, we demonstrated that TRIM37 expression was notably up-regulated in HCC samples and was associated with advanced stage and tumor volume, which all indicating the poor outcomes. We also found that TRIM37 could serve as an independent prognostic factor of HCC. During the course of in vitro and in vivo work, we showed that TRIM37 promoted HCC cells migration and metastasis by inducing EMT. Furthermore, we revealed that the effect of TRIM37 mediated EMT in HCC cells was achieved by the activation of Wnt/β-catenin signaling. These finding may provide insight into the understanding of TRIM37 as a novel critical factor of HCC and a candidate target for HCC treatment. - Highlights: • Highly expression of TRIM37 is found in HCC samples compared with nontumorous samples. • TRIM37 expression is correlated with advanced HCC stages and could be an independent prognostic factor. • TRIM37 promotes cell proliferation and metastasis. • We report an E3 ligase TRIM37 affects Wnt/β-catenin signaling.

  3. Concomitant activation of P2Y(2) and P2Y(6) receptors on monocytes is required for TLR1/2-induced neutrophil migration by regulating IL-8 secretion.

    PubMed

    Ben Yebdri, Fethia; Kukulski, Filip; Tremblay, Alain; Sévigny, Jean

    2009-10-01

    Extracellular nucleotides regulate a variety of cellular responses involved in inflammation via the activation of P2 receptors. Here, we show that nucleotides regulate TLR2-induced neutrophil migration both in vivo and in vitro. The nucleotide scavenger apyrase inhibited neutrophil recruitment in murine air pouches injected with the TLR2 agonist Pam(3)CSK(4). In agreement, the supernatants of either human primary monocytes or monocytic cells (THP-1 and U937) treated with Pam(3)CSK(4) recruited significantly fewer neutrophils when the former cells were treated in the presence of apyrase. As demonstrated with inhibitory Ab, these supernatants induced neutrophil migration due to IL-8 secretion. In addition, IL-8 secretion was markedly diminished by the non-selective P2 receptor antagonists reactive blue 2 and suramin, and by a selective P2Y(6) antagonist, MRS2578. Selective antagonists of P2Y(1) (MRS2500) and P2Y(11) (NF157) did not affect IL-8 release. The knockdown of either P2Y(2) or P2Y(6) with specific shRNA diminished IL-8 secretion from Pam(3)CSK(4)-treated THP-1 cells. Altogether, these results show that extracellular nucleotides, via P2Y(2) and P2Y(6) receptors, regulate neutrophil migration by controlling TLR2-induced IL-8 release from human monocytes. In line with our previous work on TLR4, this study further supports the importance of nucleotides in bacterial-induced neutrophil migration.

  4. Desmoglein 3 promotes cancer cell migration and invasion by regulating activator protein 1 and protein kinase C-dependent-Ezrin activation.

    PubMed

    Brown, L; Waseem, A; Cruz, I N; Szary, J; Gunic, E; Mannan, T; Unadkat, M; Yang, M; Valderrama, F; O'Toole, E A; Wan, H

    2014-05-01

    Desmoglein 3 (Dsg3), the pemphigus vulgaris antigen, has recently been shown to be upregulated in squamous cell carcinoma (SCC) and has been identified as a good tumor-specific marker for clinical staging of cervical sentinel lymph nodes in head and neck SCC. However, little is known about its biological function in cancer. The actin-binding protein Ezrin and the activator protein 1 (AP-1) transcription factor are implicated in cancer progression and metastasis. Here, we report that Dsg3 regulates the activity of c-Jun/AP-1 as well as protein kinase C (PKC)-mediated phosphorylation of Ezrin-Thr567, which contributes to the accelerated motility of cancer cells. Ectopic expression of Dsg3 in cancer cell lines caused enhanced phosphorylation at Ezrin-Thr567 with concomitant augmented membrane protrusions, cell spreading and invasive phenotype. We showed that Dsg3 formed a complex with Ezrin at the plasma membrane that was required for its proper function of interacting with F-actin and CD44 as Dsg3 knockdown impaired these associations. The increased Ezrin phosphorylation in Dsg3-overexpressing cells could be abrogated substantially by various pharmacological inhibitors for Ser/Thr kinases, including PKC and Rho kinase that are known to activate Ezrin. Furthermore, a marked increase in c-Jun S63 phosphorylation, among others, was found in Dsg3-overexpressing cells and the activation of c-Jun/AP-1 was further supported by a luciferase reporter assay. Taken together, our study identifies a novel Dsg3-mediated c-Jun/AP-1 regulatory mechanism and PKC-dependent Ezrin phosphorylation that could be responsible for Dsg3-associated cancer metastasis.

  5. Migration and its risks.

    PubMed

    O'brien, P

    1996-01-01

    "This essay applies the theories of Ulrich Beck...to the politics of migration in Germany. In particular, the essay focuses on Beck's notion of the waning influence, indeed even relevancy, of science and scientists regarding postmodern risk phenomena. The essay argues that migration to Germany can be understood as a Beckian risk phenomenon, helping to explain the decreasing influence of social scientists over the politics of migration in the Federal Republic."

  6. Rh(III)-Catalyzed Cascade Annulation/C-H Activation of o-Ethynylanilines with Diazo Compounds: One-Pot Synthesis of Benzo[a]carbazoles via 1,4-Rhodium Migration.

    PubMed

    Guo, Songjin; Yuan, Kai; Gu, Meng; Lin, Aijun; Yao, Hequan

    2016-10-05

    A Rh(III)-catalyzed cascade annulation/C-H activation of o-ethynylanilines with diazo compounds has been developed. This concise method allows for the rapid formation of a number of benzo[a]carbazoles in high yields, exhibiting good functional group tolerance and scalability. The key to the success of this approach involves one C-N bond and two C-C bond formation, and an aryl-to-aryl 1,4-rhodium migration.

  7. Control of cortical neuronal migration by glutamate and GABA.

    PubMed

    Luhmann, Heiko J; Fukuda, A; Kilb, W

    2015-01-01

    Neuronal migration in the cortex is controlled by the paracrine action of the classical neurotransmitters glutamate and GABA. Glutamate controls radial migration of pyramidal neurons by acting primarily on NMDA receptors and regulates tangential migration of inhibitory interneurons by activating non-NMDA and NMDA receptors. GABA, acting on ionotropic GABAA-rho and GABAA receptors, has a dichotomic action on radially migrating neurons by acting as a GO signal in lower layers and as a STOP signal in upper cortical plate (CP), respectively. Metabotropic GABAB receptors promote radial migration into the CP and tangential migration of interneurons. Besides GABA, the endogenous GABAergic agonist taurine is a relevant agonist controlling radial migration. To a smaller extent glycine receptor activation can also influence radial and tangential migration. Activation of glutamate and GABA receptors causes increases in intracellular Ca(2+) transients, which promote neuronal migration by acting on the cytoskeleton. Pharmacological or genetic manipulation of glutamate or GABA receptors during early corticogenesis induce heterotopic cell clusters in upper layers and loss of cortical lamination, i.e., neuronal migration disorders which can be associated with neurological or neuropsychiatric diseases. The pivotal role of NMDA and ionotropic GABA receptors in cortical neuronal migration is of major clinical relevance, since a number of drugs acting on these receptors (e.g., anti-epileptics, anesthetics, alcohol) may disturb the normal migration pattern when present during early corticogenesis.

  8. Control of cortical neuronal migration by glutamate and GABA

    PubMed Central

    Luhmann, Heiko J.; Fukuda, A.; Kilb, W.

    2015-01-01

    Neuronal migration in the cortex is controlled by the paracrine action of the classical neurotransmitters glutamate and GABA. Glutamate controls radial migration of pyramidal neurons by acting primarily on NMDA receptors and regulates tangential migration of inhibitory interneurons by activating non-NMDA and NMDA receptors. GABA, acting on ionotropic GABAA-rho and GABAA receptors, has a dichotomic action on radially migrating neurons by acting as a GO signal in lower layers and as a STOP signal in upper cortical plate (CP), respectively. Metabotropic GABAB receptors promote radial migration into the CP and tangential migration of interneurons. Besides GABA, the endogenous GABAergic agonist taurine is a relevant agonist controlling radial migration. To a smaller extent glycine receptor activation can also influence radial and tangential migration. Activation of glutamate and GABA receptors causes increases in intracellular Ca2+ transients, which promote neuronal migration by acting on the cytoskeleton. Pharmacological or genetic manipulation of glutamate or GABA receptors during early corticogenesis induce heterotopic cell clusters in upper layers and loss of cortical lamination, i.e., neuronal migration disorders which can be associated with neurological or neuropsychiatric diseases. The pivotal role of NMDA and ionotropic GABA receptors in cortical neuronal migration is of major clinical relevance, since a number of drugs acting on these receptors (e.g., anti-epileptics, anesthetics, alcohol) may disturb the normal migration pattern when present during early corticogenesis. PMID:25688185

  9. Migration and distribution of water and organic matter for activated sludge during coupling magnetic conditioning-horizontal electro-dewatering (CM-HED).

    PubMed

    Qian, Xu; Wang, Yili; Zheng, Huaili

    2016-01-01

    Magnetic micro-particles (MMPs) and magnetic field (MF) were utilized as a coupling conditioning unit before dewatering activated sludge (AS) under a horizontal electric field. The removal and migration of free and bound water in AS during coupling magnetic conditioning-horizontal electro-dewatering (CM-HED) were determined. The organic matter migration between the solid and liquid phases of AS biosolids was also analyzed. Results show that MMPs dosage and MF intensity were determined as 0.15 g/g dry solids and 0.065 T for the best dewaterability, respectively. The optimum dewatering conditions for CM-HED with the final water content of 89.98% were 40 V and 120 min as determined using the response surface methodology. MMPs conditioning could induce a slight coagulation among AS flocs, increase the particle size from 85.9 μm to 92.3 μm and decrease mass fractal dimension from 2.18 to 2.07. The MMPs-conditioned AS also showed a network-like structure, banded cells with shrunk surfaces. CM-HED process effectively reduced the free water content (FWC) and bound water content (BWC) but increased the portion of BWC in AS. The corresponding removal ratios of bound water and free water were 52.89% and 95.86% at the anode side and 46.28% and 92.75% at the cathode side, respectively. The coupling magnetic conditioning led to the largest BWC reduction of 23.14% in CM-HED process, and most of this reduction approaching 92.83% occurred during magnetic micro-particle conditioning stage. Gravity field caused the largest sludge reduction of 87.45%. During HED stage, the removal ratio of free water in AS was 63.73% at the anode side and 36.54% at the cathode side, while it was 21.9% and 10.96% for bound water, respectively. Along with water removed by CM-HED process, the organic matter in supernatant/filtrate increased, and a sharp rise occurred during HED stage. Meanwhile, the extracellular polymeric substance (EPS) contents initially decreased at MMPs-MF conditioning stage

  10. The Asian-American variant of human papillomavirus type 16 exhibits higher activation of MAPK and PI3K/AKT signaling pathways, transformation, migration and invasion of primary human keratinocytes.

    PubMed

    Hochmann, Jimena; Sobrinho, João S; Villa, Luisa L; Sichero, Laura

    2016-05-01

    Asian-American (AA) HPV-16 variants are associated with higher risk of cancer. Abnormal activation of intracellular signaling play a critical role in cancer development and progression. Our aim was to elucidate mechanisms underlying the higher oncogenic potential attributed to AA variant. We evaluated activation of MAPK and PI3K/AKT pathways in primary human keratinocytes (PHKs) transduced with E6/E7 of three HPV-16 variants: E-P, AA, E-350G. Phenotypes examined included migration, anchorage independent growth and invasion. AA PHKs presented the highest levels of active proteins involved in all cascades analyzed: MAPK-ERK, MAPK-p38 and PI3K-AKT. AA PHKs were more efficient in promoting anchorage independent growth, and in stimulating cell migration and invasion. MEK1 inhibition decreased migration. The mesenchymal phenotype marker vimentin was increased in AA PHKs. Our results suggest that MEK1, ERK2, AKT2 hyperactivation influence cellular behavior by means of GSK-3b inactivation and EMT induction prompting AA immortalized PHKs to more efficiently surpass carcinogenesis steps.

  11. Exogenous hydrogen sulfide exerts proliferation/anti-apoptosis/angiogenesis/migration effects via amplifying the activation of NF-κB pathway in PLC/PRF/5 hepatoma cells.

    PubMed

    Zhen, Yulan; Pan, Wanying; Hu, Fen; Wu, Hongfu; Feng, Jianqiang; Zhang, Ying; Chen, Jingfu

    2015-05-01

    Hydrogen sulfide (H2S) takes part in a diverse range of intracellular pathways and hss physical and pathological properties in vitro and in vivo. However, the effects of H2S on cancer are controversial and remain unclear. The present study investigates the effects of H2S on liver cancer progression via activating NF-κB pathway in PLC/PRF/5 hepatoma cells. PLC/PRF/5 hepatoma cells were pretreated with 500 µmol/l NaHS (a donor of H2S) for 24 h. The expression levels of CSE, CBS, phosphosphorylate (p)-NF-κB p65, caspase-3, COX-2, p-IκB and MMP-2 were measured by western blot assay. Cell viability was detected by cell counter kit 8 (CCK-8). Apoptotic cells were observed by Hoechst 33258 staining assay. The production level of H2S in cell culture medium was measured by using the sulfur-sensitive electrode method. The production of vascular endothelial growth factor (VEGF) was tested by enzyme-linked immunosorbent assay (ELISA). Our results showed that the production of H2S was dramatically increased in the PLC/PRF/5 hepatoma cells, compared with human LO2 hepatocyte cells group, along with the overexpression levels of CSE and CBS. Treatment of PLC/PRF/5 hepatoma cells with 500 µmol/l NaHS (a donor of H2S) for 24 h markedly increased the expression levels of CSE, CBS, p-IκB and NF-κB activation, leading to COX-2 and MMP-2 overexpression, and decreased caspase-3 production, as well as increased cell viability and decreased number of apoptotic cells. Otherwise, the production level of H2S and VEGF were also significantly increased. Furthermore, co-treatment of PLC/PRF/5 hepatoma cells with 500 µmol/l NaHS and 200 µmol/l PDTC for 24 h significantly overturned these indexes. The findings of the present study provide evidence that the NF-κB is involved in the NaHS-induced cell proliferation, anti-apoptisis, angiogenesis, and migration in PLC/PRF/5 hepatoma cells, and that the PDTC against the NaHS-induced effects were by inhibition of the NF-κB pathway.

  12. Vaccination against canine leishmaniosis increases the phagocytic activity, nitric oxide production and expression of cell activation/migration molecules in neutrophils and monocytes.

    PubMed

    Moreira, Marcela L; Costa-Pereira, Christiane; Alves, Marina Luiza Rodrigues; Marteleto, Bruno H; Ribeiro, Vitor M; Peruhype-Magalhães, Vanessa; Giunchetti, Rodolfo C; Martins-Filho, Olindo A; Araújo, Márcio S S

    2016-04-15

    Visceral leishmaniasis (VL) is transmitted by phlebotomine sandfly vectors and domestic dogs serve as a reservoir. The elimination of seropositive dogs has been a recommended strategy for managing the disease in Brazil. A protective canine vaccine would be an important tool for controlling the disease, reducing the parasites available to sandfly vectors and, consequently, reducing the number of human VL cases. Leishmune(®) is an anti-canine Leishmaniosis (VL Canine) vaccine produced by Zoetis (Pfizer, Brazil) that was commercially available in Brazil until 2014. The main goal of the present study was to investigate the protective immunological events induced by vaccination with Leishmune(®) in the time frame of one year. Healthy, non-vaccinated dogs and dogs of 1, 6 and 10 months post-vaccination were evaluated. Results showed that Leishmune(®) induced an increase in phagocytic activity of neutrophils and monocytes and also increased NO production. Immunological events were correlated with functional responses, as high levels of IgG and an increase of the receptor Fcγ were detected. Vaccination induced an increased expression of TLR (2, 4, 5, 9), integrin (CD29, CD49f), activation (MHCII) and co-stimulatory (CD80, CD81) molecules by neutrophils and monocytes. Vaccination led to decrease of IL-4 and an increase of IL-8 production by monocytes and higher IFN-γ and IL-17 production by T-cells. The results suggested that Leishmune(®) was able to induce a long-lasting change in immune response, mediated by supportive immunological events that may be participating in protective immunity against CL.

  13. Endothelial cell migration during murine yolk sac vascular remodeling occurs by means of a Rac1 and FAK activation pathway in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The molecular mechanism(s) controlling cell migration during vascular morphogenesis in vivo remain largely undefined. To address this within a physiological context, we used retinaldehyde dehydrogenase-2 (Raldh2) null mouse embryos and demonstrate that retinoic acid (RA) deficiency results in abnorm...

  14. Cell migration, freshly squeezed.

    PubMed

    Welch, Matthew D

    2015-02-12

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

  15. Migration and Environmental Hazards

    PubMed Central

    Hunter, Lori M.

    2011-01-01

    Losses due to natural hazards (e.g., earthquakes, hurricanes) and technological hazards (e.g., nuclear waste facilities, chemical spills) are both on the rise. One response to hazard-related losses is migration, with this paper offering a review of research examining the association between migration and environmental hazards. Using examples from both developed and developing regional contexts, the overview demonstrates that the association between migration and environmental hazards varies by setting, hazard types, and household characteristics. In many cases, however, results demonstrate that environmental factors play a role in shaping migration decisions, particularly among those most vulnerable. Research also suggests that risk perception acts as a mediating factor. Classic migration theory is reviewed to offer a foundation for examination of these associations. PMID:21886366

  16. Monocyte and neutrophil isolation and migration assays.

    PubMed

    Yona, Simon; Hayhoe, Richard; Avraham-Davidi, Inbal

    2010-02-01

    This unit describes methods for isolating mouse monocytes and neutrophils, as well as in vitro protocols for measuring cell migration and polarization. The method employed here for the isolation of naïve phagocytes overcomes many of the difficulties previously encountered concerning phagocyte activation. Three in vitro protocols are provided for the analysis of cell migration, one requiring no specialized equipment, one requiring the modified Boyden chamber, and the other employing a flow chamber, which measures cell adhesion, rolling, and migration. Finally, a method is provided for imaging polarized cells by confocal microscopy.

  17. Time-dependent evolution of the Bi3.64Mo0.36O6.55/Bi2MoO6 heterostructure for enhanced photocatalytic activity via the interfacial hole migration

    NASA Astrophysics Data System (ADS)

    Dai, Zan; Qin, Fan; Zhao, Huiping; Tian, Fan; Liu, Yunling; Chen, Rong

    2015-07-01

    Hierarchical Bi3.64Mo0.36O6.55/Bi2MoO6 isotype heterostructures were successfully prepared via a one-pot hydrothermal route by using Bi2O3 porous nanospheres as a sacrificial template. By tuning the reaction time, the formation process of the Bi3.64Mo0.36O6.55/Bi2MoO6 heterostructure involving Mo etching, phase transition and anisotropic growth was clearly identified. More importantly, the Bi3.64Mo0.36O6.55/Bi2MoO6 heterostructure displayed remarkably enhanced photocatalytic activity for dye photodegradation than pure phase bismuth molybdate due to the efficient electron-hole separation and the interfacial photogenerated hole migration from inside the Bi3.64Mo0.36O6.55 layer to outside the Bi2MoO6 layer. The opposite hole migration from the outer layer to the inner layer was also detected in Bi2O3/Bi2WO6 heterostructures, which resulted in the decrease of photocatalytic activity, further verifying the importance of hole migration direction. This work provides a novel route to fabricate heterostructured photocatalysts, as well as gives a strategy for mediating the charge migration to improve photocatalytic performance.Hierarchical Bi3.64Mo0.36O6.55/Bi2MoO6 isotype heterostructures were successfully prepared via a one-pot hydrothermal route by using Bi2O3 porous nanospheres as a sacrificial template. By tuning the reaction time, the formation process of the Bi3.64Mo0.36O6.55/Bi2MoO6 heterostructure involving Mo etching, phase transition and anisotropic growth was clearly identified. More importantly, the Bi3.64Mo0.36O6.55/Bi2MoO6 heterostructure displayed remarkably enhanced photocatalytic activity for dye photodegradation than pure phase bismuth molybdate due to the efficient electron-hole separation and the interfacial photogenerated hole migration from inside the Bi3.64Mo0.36O6.55 layer to outside the Bi2MoO6 layer. The opposite hole migration from the outer layer to the inner layer was also detected in Bi2O3/Bi2WO6 heterostructures, which resulted in the decrease

  18. PDGFRα signaling in the primary cilium regulates NHE1-dependent fibroblast migration via coordinated differential activity of MEK1/2–ERK1/2–p90RSK and AKT signaling pathways

    PubMed Central

    Clement, Ditte L.; Mally, Sabine; Stock, Christian; Lethan, Mette; Satir, Peter; Schwab, Albrecht; Pedersen, Stine F.; Christensen, Søren T.

    2013-01-01

    Summary In fibroblasts, platelet-derived growth factor receptor alpha (PDGFRα) is upregulated during growth arrest and compartmentalized to the primary cilium. PDGF-AA mediated activation of the dimerized ciliary receptor produces a phosphorylation cascade through the PI3K–AKT and MEK1/2–ERK1/2 pathways leading to the activation of the Na+/H+ exchanger, NHE1, cytoplasmic alkalinization and actin nucleation at the lamellipodium that supports directional cell migration. We here show that AKT and MEK1/2–ERK1/2–p90RSK inhibition reduced PDGF-AA-induced cell migration by distinct mechanisms: AKT inhibition reduced NHE1 activity by blocking the translocation of NHE1 to the cell membrane. MEK1/2 inhibition did not affect NHE1 activity but influenced NHE1 localization, causing NHE1 to localize discontinuously in patches along the plasma membrane, rather than preferentially at the lamellipodium. We also provide direct evidence of NHE1 translocation through the cytoplasm to the leading edge. In conclusion, signals initiated at the primary cilium through the PDGFRαα cascade reorganize the cytoskeleton to regulate cell migration differentially through the AKT and the MEK1/2–ERK1/2–p90RSK pathways. The AKT pathway is necessary for initiation of NHE1 translocation, presumably in vesicles, to the leading edge and for its activation. In contrast, the MEK1/2–ERK1/2–p90RSK pathway controls the spatial organization of NHE1 translocation and incorporation, and therefore specifies the direction of the leading edge formation. PMID:23264740

  19. PDGFRα signaling in the primary cilium regulates NHE1-dependent fibroblast migration via coordinated differential activity of MEK1/2-ERK1/2-p90RSK and AKT signaling pathways.

    PubMed

    Clement, Ditte L; Mally, Sabine; Stock, Christian; Lethan, Mette; Satir, Peter; Schwab, Albrecht; Pedersen, Stine F; Christensen, Søren T

    2013-02-15

    In fibroblasts, platelet-derived growth factor receptor alpha (PDGFRα) is upregulated during growth arrest and compartmentalized to the primary cilium. PDGF-AA mediated activation of the dimerized ciliary receptor produces a phosphorylation cascade through the PI3K-AKT and MEK1/2-ERK1/2 pathways leading to the activation of the Na(+)/H(+) exchanger, NHE1, cytoplasmic alkalinization and actin nucleation at the lamellipodium that supports directional cell migration. We here show that AKT and MEK1/2-ERK1/2-p90(RSK) inhibition reduced PDGF-AA-induced cell migration by distinct mechanisms: AKT inhibition reduced NHE1 activity by blocking the translocation of NHE1 to the cell membrane. MEK1/2 inhibition did not affect NHE1 activity but influenced NHE1 localization, causing NHE1 to localize discontinuously in patches along the plasma membrane, rather than preferentially at the lamellipodium. We also provide direct evidence of NHE1 translocation through the cytoplasm to the leading edge. In conclusion, signals initiated at the primary cilium through the PDGFRαα cascade reorganize the cytoskeleton to regulate cell migration differentially through the AKT and the MEK1/2-ERK1/2-p90(RSK) pathways. The AKT pathway is necessary for initiation of NHE1 translocation, presumably in vesicles, to the leading edge and for its activation. In contrast, the MEK1/2-ERK1/2-p90(RSK) pathway controls the spatial organization of NHE1 translocation and incorporation, and therefore specifies the direction of the leading edge formation.

  20. Migration and AIDS.

    PubMed

    1998-01-01

    This article presents the perspectives of UNAIDS and the International Organization for Migration (IOM) on migration and HIV/AIDS. It identifies research and action priorities and policy issues, and describes the current situation in major regions of the world. Migration is a process. Movement is enhanced by air transport, rising international trade, deregulation of trade practices, and opening of borders. Movements are restricted by laws and statutes. Denial to freely circulate and obtain asylum is associated with vulnerability to HIV infections. A UNAIDS policy paper in 1997 and IOM policy guidelines in 1988 affirm that refugees and asylum seekers should not be targeted for special measures due to HIV/AIDS. There is an urgent need to provide primary health services for migrants, voluntary counseling and testing, and more favorable conditions. Research is needed on the role of migration in the spread of HIV, the extent of migration, availability of health services, and options for HIV prevention. Research must be action-oriented and focused on vulnerability to HIV and risk taking behavior. There is substantial mobility in West and Central Africa, economic migration in South Africa, and nonvoluntary migration in Angola. Sex workers in southeast Asia contribute to the spread. The breakup of the USSR led to population shifts. Migrants in Central America and Mexico move north to the US where HIV prevalence is higher.

  1. Receptor-interacting protein kinase 2 promotes triple-negative breast cancer cell migration and invasion via activation of nuclear factor-kappaB and c-Jun N-terminal kinase pathways

    PubMed Central

    2014-01-01

    Introduction Metastasis is the main cause of breast cancer morbidity and mortality. Processes that allow for tumor cell migration and invasion are important therapeutic targets. Here we demonstrate that receptor-interacting protein kinase 2 (RIP2), a kinase known to be involved in inflammatory processes, also has novel roles in cancer cell migration and invasion. Methods A total of six breast cancer expression databases, including The Cancer Genome Atlas, were assessed for RIP2 expression among various clinical subtypes and its role as a prognostic biomarker. mRNA fluorescence in situ hybridization (FISH) for RIP2 was performed on 17 stage III breast cancers to determine if there was a correlation between RIP2 expression and lymph node involvement. RNA-interference was used to knock-down RIP2 expression in MDA-MB-231, Htb126, SUM149PT, MCF7, T47D, and HCC1428 cells. Cell migration and invasion were measured in vitro by scratch/wound healing and transwell migration assays. A xenograft mouse model was used to assess tumor growth and chemosensitivity to docetaxel in vivo in MDA-MB-231 cells with and without RIP2 small hairpin RNA knockdown. Western blot and immunofluorescence imaging were used to evaluate protein expressions. Results Interrogation of expression databases showed that RIP2 expression is significantly over-expressed in triple-negative breast cancers (TNBC: estrogen-receptor (ER) negative, progesterone-receptor (PR) negative, Her2/neu- (Her2) negative), compared to other clinical subtypes. High RIP2 expression correlates with worse progression-free survival using a combined breast cancer expression array dataset consisting of 946 patients. Multivariate analysis shows RIP2 as an independent prognostic biomarker. Knock-down of RIP2 significantly decreases migration in both scratch/wound healing and transwell migration assays in MDA-MB-231, Htb126, SUM149PT, MCF7, and T47D cells and is correlated with decreased Nuclear Factor-kappaB and c-Jun N

  2. Inhibition of fatty acid synthase suppresses U-2 OS cell invasion and migration via downregulating the activity of HER2/PI3K/AKT signaling pathway in vitro

    SciTech Connect

    Wang, Tao Fang; Wang, Heng; Peng, Ai Fen; Luo, Qing Feng; Liu, Zhi Li; Zhou, Rong Ping; Gao, Song; Zhou, Yang; Chen, Wen Zhao

    2013-10-18

    Highlights: •We investigate the relationship between FASN and HER2 or p-HER2 by IHC in OS tissues. •We construct FASN-specific RNAi plasmid. •Inhibiting FASN down-regulates HER2/PI3K/AKT cell signaling in U-2 OS. •Inhibiting FASN blocks U-2 OS cell invasion and migration. -- Abstract: FASN plays an important role in the malignant phenotype of various tumors. Our previous studies show that inhibition FASN could induce apoptosis and inhibit proliferation in human osteosarcoma (OS) cell in vivo and vitro. The aim in this study was to investigate the effect of inhibition FASN on the activity of HER2/PI3K/AKT axis and invasion and migration of OS cell. The expression of FASN, HER2 and p-HER2(Y1248) proteins was detected by immunohistochemistry in OS tissues from 24 patients with pulmonary metastatic disease, and the relationship between FASN and p-HER2 as well as HER2 was investigated. The results showed that there was a positive correlation between FASN and HER2 as well as p-HER2 protein expression. The U-2 OS cells were transfected with either the FASN specific RNAi plasmid or the negative control RNAi plasmid. FASN mRNA was measured by RT-PCR. Western blot assays was performed to examine the protein expression of FASN, HER2, p-HER2(Y1248), PI3K, Akt and p-Akt (Ser473). Migration and invasion of cells were investigated by wound healing and transwell invasion assays. The results showed that the activity of HER2/PI3K/AKT signaling pathway was suppressed by inhibiting FASN. Meanwhile, the U-2OS cells migration and invasion were also impaired by inhibiting the activity of FASN/HER2/PI3K/AKT. Our results indicated that inhibition of FASN suppresses OS cell invasion and migration via down-regulation of the “HER2/PI3K/AKT” axis in vitro. FASN blocker may be a new therapeutic strategy in OS management.

  3. DLC-1, a GTPase-activating protein for Rho, is associated with cell proliferation, morphology, and migration in human hepatocellular carcinoma

    SciTech Connect

    Kim, Tai Young; Lee, Jung Weon; Kim, Hwang-Phill; Jong, Hyun-Soon; Kim, Tae-You; Jung, Mira; Bang, Yung-Jue; E-mail: bangyj@plaza.snu.ac.kr

    2007-03-30

    DLC-1 (deleted in liver cancer-1) is a tumor suppressor gene for hepatocellular carcinoma and other cancers. To characterize its functions, we constructed recombinant adenovirus encoding the wild-type DLC-1 and examined its effects on behaviors of a hepatocellular carcinoma cell line (SNU-368), which does not express DLC-1. Here, we found that restoration of DLC-1 expression in the SNU-368 cells caused an inhibition of cell proliferation with an increase of a subG1 population. Furthermore, DLC-1 overexpression induced disassembly of stress fibers and extensive membrane protrusions around cells on laminin-1. DLC-1 overexpression also inhibited cell migration and dephosphorylated focal adhesion proteins such as focal adhesion kinase (FAK), Cas (p130Cas; Crk-associated substrate), and paxillin. These observations suggest that DLC-1 plays important roles in signal transduction pathway regulating cell proliferation, cell morphology, and cell migration by affecting Rho family GTPases and focal adhesion proteins.

  4. Down-regulation of mir-221 and mir-222 restrain prostate cancer cell proliferation and migration that is partly mediated by activation of SIRT1.

    PubMed

    Yang, Xiao; Yang, Yingmei; Gan, Rong; Zhao, Lingxu; Li, Wei; Zhou, Huaibin; Wang, Xiaojuan; Lu, Jianxin; Meng, Qing H

    2014-01-01

    Studies have shown that miR-221 and miR-222 are deregulated in many cancers, including prostate cancer. Nevertheless, the biological role and the underlying mechanisms of miR-221 and miR-222 in the pathogenesis of androgen-independent prostate cancer are still not clear. The proliferation, apoptosis, cell cycle distinction, and migration capacity of prostate cells were determined following transfection of miR-221 or miR-222 inhibitor. The biological impact and regulation of SIRT1 on prostate cancer cells were investigated. MiR-221 and miR-222 were highly expressed in PC-3 cells compared with in LNCap cells. After miR-221 or miR-222 expression was inhibited, the proliferation and migration rates of PC-3 cells decreased and the apoptosis rate increased. Moreover, SIRT1 protein was up-regulated in cells after they were transfected with miR-221 or miR-222 inhibitor. Cells transfected with siSIRT1 showed increased migration and a decreased apoptosis rate, but there was no significant effect on cell proliferation compared with the controls. There was a negative correlation between miR-221 or miR-222 and SIRT1, but no direct target relationship was identified. These data demonstrate that miR-221 and miR-222 are highly expressed in PC-3 cells. Their inhibition leads to reduced cell proliferation and migration and increased apoptosis in prostate cancer cells. These effects are potentially mediated by up-regulation of SIRT1.

  5. VEGF induces proliferation, migration, and TGF-{beta}1 expression in mouse glomerular endothelial cells via mitogen-activated protein kinase and phosphatidylinositol 3-kinase

    SciTech Connect

    Li Zhaodong; Bork, Jens Peter; Krueger, Bettina; Patsenker, Eleonora; Schulze-Krebs, Anja; Hahn, Eckhart G.; Schuppan, Detlef; E-mail: dschuppa@bidmc.harvard.edu

    2005-09-09

    The role of glomerular endothelial cells in kidney fibrosis remains incompletely understood. While endothelia are indispensable for repair of acute damage, they can produce extracellular matrix proteins and profibrogenic cytokines that promote fibrogenesis. We used a murine cell line with all features of glomerular endothelial cells (glEND.2), which dissected the effects of vascular endothelial growth factor (VEGF) on cell migration, proliferation, and profibrogenic cytokine production. VEGF dose-dependently induced glEND.2 cell migration and proliferation, accompanied by up-regulation of VEGFR-2 phosphorylation and mRNA expression. VEGF induced a profibrogenic gene expression profile, including up-regulation of TGF-{beta}1 mRNA, enhanced TGF-{beta}1 secretion, and bioactivity. VEGF-induced endothelial cell migration and TGF-{beta}1 induction were mediated by the phosphatidyl-inositol-3 kinase pathway, while proliferation was dependent on the Erk1/2 MAP kinase pathway. This suggests that differential modulation of glomerular angiogenesis by selective inhibition of the two identified VEGF-induced signaling pathways could be a therapeutic approach to treat kidney fibrosis.

  6. Computational Insights on the Mechanism of H2 Activation at Ir2S2(PPh3)4: A Combination of Multiple Reaction Pathways Involving Facile H Migration Processes.

    PubMed

    Algarra, Andrés G

    2017-01-03

    The complex Ir2S2(PPh3)4 (1) is known to react with 1 and 2 equivalents of H2 leading to [Ir(H)(PPh3)2]2(μ-S)2 (2) and Ir2(μ-S)(μ-SH)(μ-H)H2(PPh3)4 (4), respectively ( Linck , R. C. ; Pafford , R. J. ; Rauchfuss , T. B. J. Am. Chem. Soc. 2001 , 123 , 8856 - 8857 ). Herein, the results of a thorough computational (DFT) study of these formally homo- and heterolytic H2 activation processes, respectively, are presented. These indicate that 2 is formed in a two-step process whereby the oxidative addition of H2 at a single Ir(II) center of 1 generates an intermediate (A) that rearranges into 2 by means of a facile H migration to the neighboring Ir center. Activation of the second equivalent of H2 most likely occurs at the bridging sulfur ligands of 2 leading to a reaction intermediate (3aa) that features two (μ-SH) ligands. Intermediate 3aa present two isomers that differ only on the stereochemistry of the (μ-SH) ligands, and both of them can further evolve into 4 via H migration from (μ-SH) to bridging (μ-H). Nevertheless, an alternative mechanism based on the initial isomerization of 2 into A, and followed by H2 coordination and activation steps at a single Ir center cannot be completely ruled out. In general, the results herein show that the mechanisms for the activation of H2 at 1 and 2 involve facile H migration processes, in agreement with the experimentally observed intermetallic hydride exchange in 2 and the exchange between IrH and SH centers in 4, which proceed with computed free energy barriers of ca. 19-23 kcal mol(-1).

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

    PubMed

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

    2016-12-11

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

  8. Tetraspanins in Cell Migration

    PubMed Central

    Jiang, Xupin; Zhang, Jiaping; Huang, Yuesheng

    2015-01-01

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

  9. Neuronal Migration Disorders

    MedlinePlus

    ... Understanding Sleep The Life and Death of a Neuron Order Publications Support Resources Patient Organizations Professional Societies ... birth defects caused by the abnormal migration of neurons in the developing brain and nervous system. In ...

  10. Polycyclic aromatic hydrocarbon (PAH)-mediated upregulation of hepatic microRNA-181 family promotes cancer cell migration by targeting MAPK phosphatase-5, regulating the activation of p38 MAPK

    SciTech Connect

    Song, Mi-Kyung; Park, Yong-Keun; Ryu, Jae-Chun

    2013-11-15

    Growing evidence indicates that changes in microRNA (miRNA) expression in cancer induced by chemical carcinogens play an important role in cancer development and progression by regulating related genes. However, the mechanisms underlying miRNA involvement in hepatocarcinogenesis induced by polycyclic aromatic hydrocarbons (PAHs) remain unclear. Thus, the identification of aberrant miRNA expression during PAH-induced cancer cell migration will lead to a better understanding of the substantial role of miRNAs in cancer progression. In the present study, miRNA expression profiling showed significant upregulation of miR-181a, -181b, and -181d in human hepatocellular carcinoma cells (HepG2 line) exposed to benzo[a]anthracene (BA) and benzo[k]fluoranthene (BF). MAPK phosphatase-5 (MKP-5), a validated miR-181 target that deactivates MAPKs, was markedly suppressed while phosphorylation of p38 MAPK was increased after BA and BF exposure. The migration of HepG2 cells, observed using the scratch wound-healing assay, also increased in a dose-dependent manner. Depletion of miR-181 family members by miRNA inhibitors enhanced the expression of MKP-5 and suppressed the phosphorylation of p38 MAPK. Furthermore, the depletion of the miR-181 family inhibited cancer cell migration. Based on these results, we conclude that the miR-181 family plays a critical role in PAH-induced hepatocarcinogenesis by targeting MKP-5, resulting in the regulation of p38 MAPK activation. - Highlights: • We found significant upregulation of miR-181 family in HCC exposed to BA and BF. • We identified the MKP-5 as a putative target of miR-181 family. • MKP-5 was suppressed while p-P38 was increased after BA and BF exposure. • The migration of HepG2 cells increased in a dose-dependent manner.

  11. Non-Selective Cannabinoid Receptor Antagonists, Hinokiresinols Reduce Infiltration of Microglia/Macrophages into Ischemic Brain Lesions in Rat via Modulating 2-Arachidonolyglycerol-Induced Migration and Mitochondrial Activity

    PubMed Central

    Anthony Jalin, Angela M. A.; Rajasekaran, Maheswari; Prather, Paul L.; Kwon, Jin Sun; Gajulapati, Veeraswamy; Choi, Yongseok; Kim, Chunsook; Pahk, Kisoo; Ju, Chung; Kim, Won-Ki

    2015-01-01

    Growing evidence suggests that therapeutic strategies to modulate the post-ischemic inflammatory responses are promising approaches to improve stroke outcome. Although the endocannabinoid system has been emerged as an endogenous therapeutic target to regulate inflammation after stroke insult, the downstream mechanisms and their potentials for therapeutic intervention remain controversial. Here we identified trans- and cis-hinokiresinols as novel non-selective antagonists for two G-protein-coupled cannabinoid receptors, cannabinoid receptor type 1 and type 2. The Electric Cell-substrate Impedance Sensing and Boyden chamber migration assays using primary microglial cultures revealed that both hinokiresinols significantly inhibited an endocannabinoid, 2-arachidonoylglycerol-induced migration. Hinokiresinols modulated 2-arachidonoylglycerol-induced mitochondrial bioenergetics in microglia as evidenced by inhibition of ATP turnover and reduction in respiratory capacity, thereby resulting in impaired migration activity. In rats subjected to transient middle cerebral artery occlusion (1.5-h) followed by 24-h reperfusion, post-ischemic treatment with hinokiresinols (2 and 7-h after the onset of ischemia, 10 mg/kg) significantly reduced cerebral infarct and infiltration of ED1-positive microglial/macrophage cells into cerebral ischemic lesions in vivo. Co-administration of exogenous 2-AG (1 mg/kg, i.v., single dose at 2 h after starting MCAO) abolished the protective effect of trans-hinokiresionol. These results suggest that hinokiresinols may serve as stroke treatment by targeting the endocannabinoid system. Alteration of mitochondrial bioenergetics and consequent inhibition of inflammatory cells migration may be a novel mechanism underlying anti-ischemic effects conferred by cannabinoid receptor antagonists. PMID:26517721

  12. Comparative Survival Study (CSS) of Hatchery PIT-tagged Spring/Summer Chinook; Migration Years 1997-2000 Mark/Recapture Activities, 2001 Annual Report.

    SciTech Connect

    Bouwes, Nick; Petrosky, Charlie; Schaller, Howard

    2002-02-01

    The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer chinook (hereafter, chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of chinook marked in two different regions (which differ in the number of dams chinook have to migrate through) provides insight into the effects of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well comparison between the different collector projects from which smolts are transported. CSS also compares these survival rates for wild Snake River spring and summer chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species.Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts. experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. ''D'', or differential delayed mortality, is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to

  13. Voltage-gated sodium channel Nav1.7 maintains the membrane potential and regulates the activation and chemokine-induced migration of a monocyte-derived dendritic cell subset.

    PubMed

    Kis-Toth, Katalin; Hajdu, Peter; Bacskai, Ildiko; Szilagyi, Orsolya; Papp, Ferenc; Szanto, Attila; Posta, Edit; Gogolak, Peter; Panyi, Gyorgy; Rajnavolgyi, Eva

    2011-08-01

    Expression of CD1a protein defines a human dendritic cell (DC) subset with unique functional activities. We aimed to study the expression of the Nav1.7 sodium channel and the functional consequences of its activity in CD1a(-) and CD1a(+) DC. Single-cell electrophysiology (patch-clamp) and quantitative PCR experiments performed on sorted CD1a(-) and CD1a(+) immature DC (IDC) showed that the frequency of cells expressing Na(+) current, current density, and the relative expression of the SCN9A gene encoding Nav1.7 were significantly higher in CD1a(+) cells than in their CD1a(-) counterparts. The activity of Nav1.7 results in a depolarized resting membrane potential (-8.7 ± 1.5 mV) in CD1a(+) IDC as compared with CD1a(-) cells lacking Nav1.7 (-47 ± 6.2 mV). Stimulation of DC by inflammatory signals or by increased intracellular Ca(2+) levels resulted in reduced Nav1.7 expression. Silencing of the SCN9A gene shifted the membrane potential to a hyperpolarizing direction in CD1a(+) IDC, resulting in decreased cell migration, whereas pharmacological inhibition of Nav1.7 by tetrodotoxin sensitized the cells for activation signals. Fine-tuning of IDC functions by a voltage-gated sodium channel emerges as a new regulatory mechanism modulating the migration and cytokine responses of these DC subsets.

  14. Memo is a cofilin-interacting protein that influences PLCgamma1 and cofilin activities, and is essential for maintaining directionality during ErbB2-induced tumor-cell migration.

    PubMed

    Meira, Maria; Masson, Régis; Stagljar, Igor; Lienhard, Susanne; Maurer, Francisca; Boulay, Anne; Hynes, Nancy E

    2009-03-15

    Heregulin (HRG) activates ErbB2-ErbB3 heterodimers thereby stimulating many cellular responses, including motility. Memo and PLCgamma1 interact with ErbB2 autophosphorylation sites and are essential for HRG-induced chemotaxis. By tracing HRG-stimulated cell migration in Dunn chambers, we found that Memo- or PLCgamma1 knockdown (KD) strongly impairs cell directionality. Memo has no obvious enzymatic activity and was discovered via its ability to complex with ErbB2. Using the yeast two-hybrid approach to gain insight into Memo function, an interaction between Memo and cofilin, a regulator of actin dynamics, was uncovered. The interaction was confirmed in vitro using recombinant proteins and in vivo in co-immunoprecipitation experiments where Memo was detected in complexes with cofilin, ErbB2 and PLCgamma1. Interestingly, in Memo KD cells, HRG-induced PLCgamma1 phosphorylation was decreased, suggesting that Memo regulates PLCgamma1 activation. Furthermore, HRG-induced recruitment of GFP-cofilin to lamellipodia is impaired in Memo and in PLCgamma1 KD cells, suggesting that both proteins lie upstream of cofilin in models of ErbB2-driven tumor-cell migration. Finally, in vitro F-actin binding and depolymerization assays showed that Memo enhances cofilin depolymerizing and severing activity. In summary, these data indicate that Memo also regulates actin dynamics by interacting with cofilin and enhancing its function.

  15. Indonesia's migration transition.

    PubMed

    Hugo, G

    1995-01-01

    This article describes population movements in Indonesia in the context of rapid and marked social and economic change. Foreign investment in Indonesia is increasing, and global mass media is available to many households. Agriculture is being commercialized, and structural shifts are occurring in the economy. Educational levels are increasing, and women's role and status are shifting. Population migration has increased over the decades, both short and long distance, permanent and temporary, legal and illegal, and migration to and between urban areas. This article focuses specifically on rural-to-urban migration and international migration. Population settlements are dense in the agriculturally rich inner areas of Java, Bali, and Madura. Although the rate of growth of the gross domestic product was 6.8% annually during 1969-94, the World Bank ranked Indonesia as a low-income economy in 1992 because of the large population size. Income per capita is US $670. Indonesia is becoming a large exporter of labor to the Middle East, particularly women. The predominance of women as overseas contract workers is changing women's role and status in the family and is controversial due to the cases of mistreatment. Malaysia's high economic growth rate of over 8% per year means an additional 1.3 million foreign workers and technicians are needed. During the 1980s urban growth increased at a very rapid rate. Urban growth tended to occur along corridors and major transportation routes around urban areas. It is posited that most of the urban growth is due to rural-to-urban migration. Data limitations prevent an exact determination of the extent of rural-to-urban migration. More women are estimated to be involved in movements to cities during the 1980s compared to the 1970s. Recruiters and middlemen have played an important role in rural-to-urban migration and international migration.

  16. Juridical structures: refugees and migration.

    PubMed

    Veiter, T

    1988-01-01

    The juridical problems in regard to the concepts of refugee, expulsion, and migration are complicated. If one speaks about migration in Europe, one must 1st distinguish between Eastern and Western Europe. In the communist states of Eastern Europe the refugee problem does not exist officially, with the only existing refugee problem in Yugoslavia, which has signed and ratified the Geneva Refugee Convention of 1951. In the other East European states the right to asylum exists, but refugees are granted asylum only if they are persecuted in their country of origin for their communist ideas and activities. In speaking of migration, one must distinguish between migration, forced migration, mass migration, emigration, immigration, the shift of populations, and refugees. In the communist countries of Eastern Europe the right to emigration is not respected, although certain exceptions, as in Poland or Yugoslavia do exist. Generally, in the communist states emigration is not allowed and illegal emigration is punished as "Flight from the Republic." With a few exceptions, political and other persecutions are no longer so typical within Europe. In the last decades, the refugee problem has changed to other continents: Afghanistan/Pakistan, Iran, Sri Lanka, East Timor, Lebanon, Palestine, Sudan, Tchad, Ethiopia, Eritrea, and Angola. The refugee problem in Europe consists mainly in the large afflux of refugees coming from places with other cultural (and religious) attributes. The Islamic immigrants declare themselves regularly as political refugees and hope to be acknowledged as such by the receiving state. The fear of the governments and populations of the receiving countries is that it would not be possible to assimilate such aliens who do not belong to the Christian culture of Europe. Formerly, refugees came mostly from the Christian countries of Eastern Europe with the same race identity and the same religion. For years now, more and more foreign workers are a kind of migrant

  17. Using a combined population-based and kinetic modelling approach to assess timescales and durations of magma migration activities prior to the 1669 flank eruption of Mt. Etna

    NASA Astrophysics Data System (ADS)

    Kahl, M.; Morgan, D. J.; Viccaro, M.; Dingwell, D. B.

    2015-12-01

    The March-July eruption of Mt. Etna in 1669 is ranked as one of the most destructive and voluminous eruptions of Etna volcano in historical times. To assess threats from future eruptions, a better understanding of how and over what timescales magma moved underground prior to and during the 1669 eruption is required. We present a combined population based and kinetic modelling approach [1-2] applied to 185 olivine crystals that erupted during the 1669 eruption. By means of this approach we provide, for the first time, a dynamic picture of magma mixing and magma migration activity prior to and during the 1669 flank eruption of Etna volcano. Following the work of [3] we have studied 10 basaltic lava samples (five SET1 and five SET2 samples) that were erupted from different fissures that opened between 950 and 700 m a.s.l. Following previous work [1-2] we were able to classify different populations of olivine based on their overall core and rim compositional record and the prevalent zoning type (i.e. normal vs. reverse). The core plateau compositions of the SET1 and SET2 olivines range from Fo70 up to Fo83 with a single peak at Fo75-76. The rims differ significantly and can be distinguished into two different groups. Olivine rims from the SET1 samples are generally more evolved and range from Fo50 to Fo64 with a maximum at Fo55-57. SET2 olivine rims vary between Fo65-75 with a peak at Fo69. SET1 and SET2 olivines display normal zonation with cores at Fo75-76 and diverging rim records (Fo55-57 and Fo65-75). The diverging core and rim compositions recorded in the SET1 and SET2 olivines can be attributed to magma evolution possibly in three different magmatic environments (MEs): M1 (=Fo75-76), M2 (=Fo69) and M3 (=Fo55-57) with magma transfer and mixing amongst them. The MEs established in this study differ slightly from those identified in previous works [1-2]. We note the relative lack of olivines with Fo-rich core and rim compositions indicating a major mafic magma

  18. Comparative Survival [Rate] Study (CSS) of Hatchery PIT-tagged Chinook; Migration Years 1996-1998 Mark/Recapture Activities, 2000 Annual Report.

    SciTech Connect

    Berggren, Thomas J.; Basham, Larry R.

    2000-10-01

    The Comparative Survival Rate Study (CSS) is a multi-year program of the fishery agencies and tribes to measure the smolt-to-adult survival rates of hatchery spring and summer chinook at major production hatcheries in the Snake River basin and at selected hatcheries in the lower Columbia River. The CSS also compares the smolt-to-adult survival rates for Snake River basin chinook that were transported versus those that migrated in-river to below Bonneville Dam. Estimates of smolt-to-adult survival rates will be made both from Lower Granite Dam back to Lower Granite Dam (upriver stocks) and from the hatchery back to the hatchery (upriver and downriver stocks). This status report covers the first three migration years, 1996 to 1998, of the study. Study fish were implanted with a PIT (Passive Integrated Transponder) tag which allows unique identification of individual fish. Beginning in 1997, a predetermined proportion of the PIT tagged study fish in the collection/bypass channel at the transportation sites, such as Lower Granite and Little Goose dams, was purposely routed to the raceways for transportation and the rest was routed back to the river. Two categories of in-river migrating fish are used in this study. The in-river group most representative of the non-tagged fish are fish that migrate past Lower Granite, Little Goose, and Lower Monumental dams undetected in the bypass systems. This is because all non-tagged fish collected at these three dams are currently being transported. The other in-river group contains those fish remaining in-river below Lower Monumental Dam that had previously been detected at one or more dams. The number of fish starting at Lower Granite dam that are destined to one of these two in-river groups must be estimated. The Jolly-Seber capture-recapture methodology was used for that purpose. Adult (including jacks) study fish returning to the hatcheries in the Snake River basin were sampled at the Lower Granite Dam adult trap. There the PIT

  19. [International migration in Latin America].

    PubMed

    Pellegrino, A

    1995-12-01

    Trends in international migration in Latin America are reviewed using data from published sources. Aspects considered include historical views; migration according to occupational status and educational level; migration to the United States; migration characteristics in different regions of Latin America; and the crisis of the 1980s and its impact on population distribution.

  20. TGF-β1 stimulates migration of type II endometrial cancer cells by down-regulating PTEN via activation of SMAD and ERK1/2 signaling pathways.

    PubMed

    Xiong, Siyuan; Cheng, Jung-Chien; Klausen, Christian; Zhao, Jianfang; Leung, Peter C K

    2016-09-20

    PTEN acts as a tumor suppressor primarily by antagonizing the PI3K/AKT signaling pathway. PTEN is frequently mutated in human cancers; however, in type II endometrial cancers its mutation rate is very low. Overexpression of TGF-β1 and its receptors has been reported to correlate with metastasis of human cancers and reduced survival rates. Although TGF-β1 has been shown to regulate PTEN expression through various mechanisms, it is not yet known if the same is true in type II endometrial cancer. In the present study, we show that treatment with TGF-β1 stimulates the migration of two type II endometrial cancer cell lines, KLE and HEC-50. In addition, TGF-β1 treatment down-regulates both mRNA and protein levels of PTEN. Overexpression of PTEN or inhibition of PI3K abolishes TGF-β1-stimulated cell migration. TGF-β1 induces SMAD2/3 phosphorylation and knockdown of common SMAD4 inhibits the suppressive effects of TGF-β1 on PTEN mRNA and protein. Interestingly, TGF-β1 induces ERK1/2 phosphorylation and pre-treatment with a MEK inhibitor attenuates the suppression of PTEN protein, but not mRNA, by TGF-β1. This study provides important insights into the molecular mechanisms mediating TGF-β1-induced down-regulation of PTEN and demonstrates an important role of PTEN in the regulation of type II endometrial cancer cell migration.

  1. TGF-β1 stimulates migration of type II endometrial cancer cells by down-regulating PTEN via activation of SMAD and ERK1/2 signaling pathways

    PubMed Central

    Xiong, Siyuan; Cheng, Jung-Chien; Klausen, Christian; Zhao, Jianfang; Leung, Peter C.K.

    2016-01-01

    PTEN acts as a tumor suppressor primarily by antagonizing the PI3K/AKT signaling pathway. PTEN is frequently mutated in human cancers; however, in type II endometrial cancers its mutation rate is very low. Overexpression of TGF-β1 and its receptors has been reported to correlate with metastasis of human cancers and reduced survival rates. Although TGF-β1 has been shown to regulate PTEN expression through various mechanisms, it is not yet known if the same is true in type II endometrial cancer. In the present study, we show that treatment with TGF-β1 stimulates the migration of two type II endometrial cancer cell lines, KLE and HEC-50. In addition, TGF-β1 treatment down-regulates both mRNA and protein levels of PTEN. Overexpression of PTEN or inhibition of PI3K abolishes TGF-β1-stimulated cell migration. TGF-β1 induces SMAD2/3 phosphorylation and knockdown of common SMAD4 inhibits the suppressive effects of TGF-β1 on PTEN mRNA and protein. Interestingly, TGF-β1 induces ERK1/2 phosphorylation and pre-treatment with a MEK inhibitor attenuates the suppression of PTEN protein, but not mRNA, by TGF-β1. This study provides important insights into the molecular mechanisms mediating TGF-β1-induced down-regulation of PTEN and demonstrates an important role of PTEN in the regulation of type II endometrial cancer cell migration. PMID:27542208

  2. Environmental concerns and international migration.

    PubMed

    Hugo, G

    1996-01-01

    "This article focuses on international migration occurring as a result of environmental changes and processes. It briefly reviews attempts to conceptualize environment-related migration and then considers the extent to which environmental factors have been and may be significant in initiating migration. Following is an examination of migration as an independent variable in the migration-environment relationship. Finally, ethical and policy dimensions are addressed."

  3. UPLC-PDA-QTOFMS-guided isolation of prenylated xanthones and benzoylphloroglucinols from the leaves of Garcinia oblongifolia and their migration-inhibitory activity

    PubMed Central

    Zhang, Hong; Dan, Zheng; Ding, Zhi-Jie; Lao, Yuan-Zhi; Tan, Hong-Sheng; Xu, Hong-Xi

    2016-01-01

    A UPLC-PDA-QTOFMS-guided isolation strategy was employed to screen and track potentially new compounds from Garcinia oblongifolia. As a result, two new prenylated xanthones, oblongixanthones D and E (1–2), six new prenylated benzoylphloroglucinol derivatives, oblongifolins V–Z (3–7) and oblongifolin AA (8), as well as a known compound oblongifolin L (9), were isolated from the EtOAc-soluble fraction of an acetone extract of the leaves of Garcinia oblongifolia guided by UPLC-PDA-QTOFMS analysis. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic analysis and mass spectrometry. Experimental and calculated ECD spectra were used to determine the absolute configurations. The results of wound healing and transwell migration assay showed that oblongixanthones D (1), E (2), and oblongifolin L (9) have the ability to inhibit cancer cell migration in lower cytotoxic concentrations. Western blotting results showed that these compounds exhibited an anti-metastasis effect mainly through downregulating RAF protein levels. In addition, 2 and 9 could inhibit phospho-MEK and phospho-ERK at downstream. Moreover, 1, 2, and 9 could inhibit snail protein level, suggesting that they could regulate the EMT pathway. PMID:27767059

  4. UPLC-PDA-QTOFMS-guided isolation of prenylated xanthones and benzoylphloroglucinols from the leaves of Garcinia oblongifolia and their migration-inhibitory activity

    NASA Astrophysics Data System (ADS)

    Zhang, Hong; Dan, Zheng; Ding, Zhi-Jie; Lao, Yuan-Zhi; Tan, Hong-Sheng; Xu, Hong-Xi

    2016-10-01

    A UPLC-PDA-QTOFMS-guided isolation strategy was employed to screen and track potentially new compounds from Garcinia oblongifolia. As a result, two new prenylated xanthones, oblongixanthones D and E (1–2), six new prenylated benzoylphloroglucinol derivatives, oblongifolins V–Z (3–7) and oblongifolin AA (8), as well as a known compound oblongifolin L (9), were isolated from the EtOAc-soluble fraction of an acetone extract of the leaves of Garcinia oblongifolia guided by UPLC-PDA-QTOFMS analysis. The structures of the new compounds were elucidated by 1D- and 2D-NMR spectroscopic analysis and mass spectrometry. Experimental and calculated ECD spectra were used to determine the absolute configurations. The results of wound healing and transwell migration assay showed that oblongixanthones D (1), E (2), and oblongifolin L (9) have the ability to inhibit cancer cell migration in lower cytotoxic concentrations. Western blotting results showed that these compounds exhibited an anti-metastasis effect mainly through downregulating RAF protein levels. In addition, 2 and 9 could inhibit phospho-MEK and phospho-ERK at downstream. Moreover, 1, 2, and 9 could inhibit snail protein level, suggesting that they could regulate the EMT pathway.

  5. Immature myeloid Gr-1+ CD11b+ cells from lipopolysaccharide-immunosuppressed mice acquire inhibitory activity in the bone marrow and migrate to lymph nodes to exert their suppressive function.

    PubMed

    Landoni, Veronica I; Martire-Greco, Daiana; Rodriguez-Rodrigues, Nahuel; Chiarella, Paula; Schierloh, Pablo; Isturiz, Martin A; Fernández, Gabriela C

    2016-02-01

    Secondary infections due to post-sepsis immunosuppression are a major cause of death in patients with sepsis. Repetitive inoculation of increasing doses of lipopolysaccharide (LPS) into mice mimics the immunosuppression associated with sepsis. Myeloid-derived suppressor cells (MDSCs, Gr-1(+) CD11b(+)) are considered a major component of the immunosuppressive network, interfering with T-cell responses in many pathological conditions. We used LPS-immunosuppressed (IS) mice to address whether MDSCs acquired their suppressive ability in the bone marrow (BM) and whether they could migrate to lymph nodes (LNs) to exert their suppressive function. Our results showed that Gr-1(+) CD11b(+) cells of IS mice already had the potential to inhibit T-cell proliferation in the BM. Moreover, soluble factors present in the BM from IS mice were responsible for inducing this inhibitory ability in control BM cells. In addition, migration of Gr-1(+) CD11b(+) to LNs in vivo was maximal when cells obtained from the BM of IS mice were inoculated into an IS context. In this regard, we found chemoattractant activity in cell-free LN extracts (LNEs) from IS mice and an increased expression of the LN-homing chemokine receptor C-C chemokine receptor type 7 (CCR7) in IS BM Gr-1(+) CD11b(+) cells. These results indicate that Gr-1(+) CD11b(+) cells found in BM from IS mice acquire their suppressive activity in the same niche where they are generated, and migrate to LNs to exert their inhibitory role. A better understanding of MDSC generation and/or regulation of factors able to induce their inhibitory function may provide new and more effective tools for the treatment of sepsis-associated immunosuppression.

  6. Dioscorea nipponica Attenuates Migration and Invasion by Inhibition of Urokinase-Type Plasminogen Activator through Involving PI3K/Akt and Transcriptional Inhibition of NF-[Formula: see text]B and SP-1 in Hepatocellular Carcinoma.

    PubMed

    Hsieh, Ming-Ju; Yeh, Chao-Bin; Chiou, Hui-Ling; Hsieh, Ming-Chang; Yang, Shun-Fa

    2016-01-01

    High mortality and morbidity rates for hepatocellular carcinoma (HCC) in Taiwan primarily result from uncontrolled tumor metastasis. In our previous studies, we have reported that Dioscorea nipponica Makino extract (DNE) has anti-metastasis effects on human oral cancer cells. However, the effect of DNE on hepatoma metastasis have not been thoroughly investigated and remains poorly understood. To determine the effects of DNE on the migration and invasion in HCC cells we used a wound healing model, Boyden chamber assays, gelatin/casein zymography and Western blotting. Transcriptional levels of matrix metalloproteinase-9 (MMP-9) and urokinase-type plasminogen activator (u-PA) were detected by real-time PCR and promoter assays. In this study, DNE treatment significantly inhibited the migration/invasion capacities of Huh7 cell lines. The results of gelatin/casein zymography and Western blotting revealed that the activities and protein levels of the MMP-9 and u-PA were inhibited by DNE. Tests of the mRNA levels, real-time PCR, and promoter assays evaluated the inhibitory effects of DNE on u-PA expression in human hepatoma cells. A chromatin immunoprecipitation (ChIP) assay showed not only that DNE inhibits u-PA expression, but also the inhibitory effects were associated with the down-regulation of the transcription factors of NF-[Formula: see text]B and SP-1 signaling pathways. Western blot analysis also showed that DNE inhibits PI3K and phosphorylation of Akt. In conclusion, these results show that u-PA expression may be a potent therapeutic target in the DNE-mediated suppression of HCC invasion/migration. DNE may have potential use as a chemo-preventive agent against liver cancer metastasis.

  7. Down-regulation of β-catenin and the associated migration ability by Taiwanin C in arecoline and 4-NQO-induced oral cancer cells via GSK-3β activation.

    PubMed

    Hsieh, Cheng-Hong; Hsu, Hsi-Hsien; Shibu, Marthandam Asokan; Day, Cecilia-Hsuan; Bau, Da-Tian; Ho, Chih-Chu; Lin, Yueh-Min; Chen, Ming-Cheng; Wang, Shu-Huai; Huang, Chih-Yang

    2017-03-01

    Cancer is one of the leading causes of death worldwide, and oral squamous cell carcinoma (OSCC) accounts for almost a sixth of all reported cancers. Arecoline, from areca nut is known to enhance carcinogenesis in oral squamous cells. The objective of this study is to determine the effect of Taiwanin C, from Taiwania cryptomerioides Hayata against Arecoline-associated carcinogenesis. An OSCC model was created in C57BL/6J Narl mice by administrating 0.5 mg mL(-1) arecoline with 0.2 mg mL(-1) 4-NQO carcinogen for 8 and 28 wk to mimic the etiology of oral cancer patients in Asia. Mice were sacrificed and two cell lines, T28 from the tumor and N28 cancerous cell line from the surrounding non tumor area, were established. Taiwanin C showed effective anti-tumor activity in nude mice models. Taiwanin C significantly inhibited the cell viability of T28 cells in a dose dependent manner, but did not inflict any effect on N28 normal cells. Taiwanin C treatment inhibited the migration ability of T28 cells in a dose dependent manner as determined by wound healing and migration assays. Taiwanin C also reduced the levels of β-catenin and its downstream metastatic proteins, Tbx3 and c-Myc. Besides, Taiwanin C inhibited the nuclear accumulation of β-catenin and induced β-catenin degradation via proteasome-mediated pathway. Moreover, Taiwanin C enhanced GSK-3β and reduced the p-ser(9) GSK-3β protein level to inactivate Wnt signaling. Taken together, Taiwanin C blocked the cell migration effects of T28 cells mediated through the activation of GSK-3β to enhance protein degradation and reduce nuclear accumulation of β-catenin. © 2016 Wiley Periodicals, Inc.

  8. Potentiation and inhibition of migration of human neutrophils by auranofin.

    PubMed Central

    Elferink, J G; de Koster, B M

    1993-01-01

    OBJECTIVES--As auranofin resembles some neutrophil activating sulphur containing compounds, it was decided to investigate whether it had activating effects on neutrophil migration in addition to the published inhibitory effects. METHODS--The Boyden chamber assay was used to determine the migration velocity of human neutrophils. The difference between chemotaxis and chemokinesis was established with a chequerboard assay. RESULTS--Low concentrations of auranofin stimulated human neutrophil migration; concentrations of auranofin higher than 1 mumol/l were inhibitory. Inhibitors of leukotriene formation, or of protein kinase C, had the same effect on auranofin induced potentiation of migration as on fMLP activated migration. Auranofin, at a concentration of 100 nmol/l, caused a transient increase in the cGMP level of neutrophils. The auranofin induced increase in migration was strongly inhibited by methylene blue and by LY83583, two inhibitors of cGMP accumulation. CONCLUSIONS--The auranofin induced enhancement of migration is partly due to a chemokinetic effect, but mainly due to a chemotactic effect. The potentiating effect of auranofin on migration is not specifically due to the ability of the drug to inhibit protein kinase C activity or to generate leukotrienes. These results suggest that the enhancement of neutrophil migration by low levels of auranofin is related to the enhancement of cGMP levels in neutrophils. PMID:8215623

  9. Hyperbaric oxygen activates discoidin domain receptor 2 via tumour necrosis factor-alpha and the p38 MAPK pathway to increase vascular smooth muscle cell migration through matrix metalloproteinase 2.

    PubMed

    Shyu, Kou-Gi; Wang, Bao-Wei; Chang, Hang

    2009-04-01

    DDR2 (discoidin domain receptor 2) regulates collagen turnover mediated by SMCs (smooth muscle cells) in atherosclerosis. HBO (hyperbaric oxygen) has been used in medical practice; however, the molecular mechanism of the beneficial effects of HBO is poorly understood. Furthermore, the effect of HBO on DDR2 has not been reported previously. In the present study, we investigated the cellular and molecular mechanisms of DDR2 regulation by HBO in VSMCs (vascular SMCs). Cells were exposed to 2.5 ATA (atmosphere absolute) of oxygen in a hyperbaric chamber. DDR2 protein (3.63-fold) and mRNA (2.34-fold) expression were significantly increased after exposure to 2.5 ATA HBO for 1 h. Addition of SB203580 and p38 MAPK (mitogen-activated protein kinase) siRNA (small interfering RNA) 30 min before HBO inhibited the induction of DDR2 protein. HBO also significantly increased DNA-protein binding activity of Myc/Max. Addition of SB203580 and an anti-TNF-alpha (tumour necrosis factor-alpha) monoclonal antibody 30 min before HBO abolished the DNA-protein binding activity induced by HBO. HBO significantly increased the secretion of TNF-alpha from cultured VSMCs. Exogenous addition of TNF-alpha significantly increased DDR2 protein expression, whereas anti-TNF-alpha and anti-(TNF-alpha receptor) antibodies blocked the induction of DDR2 protein expression. HBO significantly increased VSMC migration and proliferation, whereas DDR2 siRNA inhibited the migration induced by HBO. HBO increased activated MMP2 (matrix metalloproteinase 2) protein expression, and DDR2 siRNA abolished the induction of activated MMP2 expression induced by HBO. In conclusion, HBO activates DDR2 expression in cultured rat VSMCs. HBO-induced DDR2 is mediated by TNF-alpha and at least in part through the p38 MAPK and Myc pathways.

  10. Migration Inhibitory Factor and Macrophage Bactericidal Function

    PubMed Central

    Simon, Harvey B.; Sheagren, John N.

    1972-01-01

    A homogeneous population of immunologically active lymphocytes was obtained from peritoneal exudates of guinea pigs with delayed hypersensitivity to bovine gamma globulin (BGG). The lymphocytes were cultured with and without BGG for 24 hr, and cell-free supernatant fluids were then assayed simultaneously for their ability to influence two in vitro parameters of macrophage function: migration from capillary tubes and bactericidal capacity. In four consecutive experiments, supernatants from antigenically stimulated lymphocytes exhibited substantial migration-inhibitory-factor activity without enhancing the ability of macrophages to kill Listeria monocytogenes. Lymphocyte lysates were inactive in both assays. Possible mechanisms of lymphocyte-macrophage interactions are discussed. PMID:4120244

  11. Migration and pension.

    PubMed

    Razin, A; Sadka, E

    1998-11-01

    "Migration has important implications for the financial soundness of the pension system.... While it is common sense to expect that young migrants, even if low-skilled, can help society pay the benefits to the currently elderly, it may nevertheless be reasonable to argue that these migrants would adversely affect current young since, after all, the migrants are net beneficiaries of the welfare state. In contrast to the adverse effects of low skilled migration in a static model, [the authors] show that in a Samuelsonian overlapping generations model...migration is a Pareto-improving measure. All the existing income (low and high) and age (young and old) groups living at the time of the migrant's arrival would be better off."

  12. More myths of migration.

    PubMed

    Basch, L; Lerner, G

    1986-01-01

    This paper discusses some of the myths of migration. The 5 myths presented are: 1) racism has little to do with the causes of migration and does not necessarily impede the adjustment or success of migrants; 2) in areas where there is a strong feminist movement and trade unions, migrant women receive their support and can count on the solidarity of these organizations; 3) transnational corporations are positive forces in the developing countries where they operate--not only do they provide these states with new sources of capital, but they also impart new industrial skills to the labor force; 4) migration today is essentially short-term in nature--it therefore does not have a strong impact on family life; and 5) most migrants cluster together in ethnic enclaves which provide a strong source of support and diminish dislocation inherent in the migrant process.

  13. Migration from Packaging Materials

    NASA Astrophysics Data System (ADS)

    Meulenaer, B. De

    Various chemical compounds can be present in foodstuffs which may induce health problems in humans. The origin of these compounds can be very diverse. Mathematical modeling can sometimes be used to predict the concentration of these chemicals in the food. Particularly for compounds which are produced in the food during, e.g., processing and for compounds which migrate from a food contact material this technique can be very fruitful. For the former type of compounds, classical chemical kinetics can be applied. In this contribution, the modeling of the migration from polymeric food contact materials is considered. This migration phenomenon can be modeled mathematically since the physical processes which govern this process are very well studied and understood. Therefore, initially some of these fundamentals will be discussed in more detail.

  14. Detecting interstellar migrations

    NASA Astrophysics Data System (ADS)

    Matloff, Gregory L.; Pazmino, John

    1997-01-01

    Interstellar migrations may occur when a civilization's star enters the red giant phase, thereby dooming the life-bearing planet. Ecologically self-contained 'world ships', massing billions of kilograms and propelled by hyperthin, space manufactured solar sails thousands of kilometers in diameter unfurled near the home star are possible vehicles to transfer a threatened civilization to a neighboring star. Consideration of the nearest red giants reveals that Pollux is the nearest formerly solar-type red giant. Known stellar neighbors of Pollux are surveyed to determine likely directions for an interstellar migration departing Pollux. Such migrations might consist of many world ships launched over millennia on voyages of about 1000 terrestrial-year duration; discovery of such events will be serendipitous. The difficulties of observing solar-sail star ships near Pollux are considered. A facility dedicated to imaging extrasolar planets within 10 parsecs might be capable of detecting these large spacecraft.

  15. Visualizing Human Migration Trhough Space and Time

    NASA Astrophysics Data System (ADS)

    Zambotti, G.; Guan, W.; Gest, J.

    2015-07-01

    Human migration has been an important activity in human societies since antiquity. Since 1890, approximately three percent of the world's population has lived outside of their country of origin. As globalization intensifies in the modern era, human migration persists even as governments seek to more stringently regulate flows. Understanding this phenomenon, its causes, processes and impacts often starts from measuring and visualizing its spatiotemporal patterns. This study builds a generic online platform for users to interactively visualize human migration through space and time. This entails quickly ingesting human migration data in plain text or tabular format; matching the records with pre-established geographic features such as administrative polygons; symbolizing the migration flow by circular arcs of varying color and weight based on the flow attributes; connecting the centroids of the origin and destination polygons; and allowing the user to select either an origin or a destination feature to display all flows in or out of that feature through time. The method was first developed using ArcGIS Server for world-wide cross-country migration, and later applied to visualizing domestic migration patterns within China between provinces, and between states in the United States, all through multiple years. The technical challenges of this study include simplifying the shapes of features to enhance user interaction, rendering performance and application scalability; enabling the temporal renderers to provide time-based rendering of features and the flow among them; and developing a responsive web design (RWD) application to provide an optimal viewing experience. The platform is available online for the public to use, and the methodology is easily adoptable to visualizing any flow, not only human migration but also the flow of goods, capital, disease, ideology, etc., between multiple origins and destinations across space and time.

  16. What's driving migration?

    PubMed

    Kane, H

    1995-01-01

    During the 1990s investment in prevention of international or internal migration declined, and crisis intervention increased. The budgets of the UN High Commissioner for Refugees and the UN Development Program remained about the same. The operating assumption is that war, persecution, famine, and environmental and social disintegration are inevitable. Future efforts should be directed to stabilizing populations through investment in sanitation, public health, preventive medicine, land tenure, environmental protection, and literacy. Forces pushing migration are likely to increase in the future. Forces include depletion of natural resources, income disparities, population pressure, and political disruption. The causes of migration are not constant. In the past, migration occurred during conquests, settlement, intermarriage, or religious conversion and was a collective movement. Current migration involves mass movement of individuals and the struggle to survive. There is new pressure to leave poor squatter settlements and the scarcities in land, water, and food. The slave trade between the 1500s and the 1800s linked continents, and only 2-3 million voluntarily crossed national borders. Involuntary migration began in the early 1800s when European feudal systems were in a decline, and people sought freedom. Official refugees, who satisfy the strict 1951 UN definition, increased from 15 million in 1980 to 23 million in 1990 but remained a small proportion of international migrants. Much of the mass movement occurs between developing countries. Migration to developed countries is accompanied by growing intolerance, which is misinformed. China practices a form of "population transfer" in Tibet in order to dilute Tibetan nationalism. Colonization of countries is a new less expensive form of control over territory. Eviction of minorities is another popular strategy in Iraq. Public works projects supported by foreign aid displace millions annually. War and civil conflicts

  17. Analysing immune cell migration.

    PubMed

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

    2009-11-01

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

  18. [Migration, climate and health].

    PubMed

    Tellier, Siri; Carballo, Manuel; Calballo, Manuel

    2009-10-26

    Many tentative connections have been postulated between migration and climate. This article points to rural-urban migration, particularly into low elevation urban slums prone to flooding as an issue needing urgent attention by health professionals. It also notes the no-man's land in which environmental refugees find themselves and the consequences this may have. Finally, it points to the urgent need to reform health systems in both developing and developed countries to adapt to rapidly changing disease patterns and to become more responsive to them.

  19. Synthetic seismic monitoring using reverse-time migration and Kirchhoff migration for CO2 sequestration in Korea

    NASA Astrophysics Data System (ADS)

    Kim, W.; Kim, Y.; Min, D.; Oh, J.; Huh, C.; Kang, S.

    2012-12-01

    During last two decades, CO2 sequestration in the subsurface has been extensively studied and progressed as a direct tool to reduce CO2 emission. Commercial projects such as Sleipner, In Salah and Weyburn that inject more than one million tons of CO2 per year are operated actively as well as test projects such as Ketzin to study the behavior of CO2 and the monitoring techniques. Korea also began the CCS (CO2 capture and storage) project. One of the prospects for CO2 sequestration in Korea is the southwestern continental margin of Ulleung basin. To monitor the behavior of CO2 underground for the evaluation of stability and safety, several geophysical monitoring techniques should be applied. Among various geophysical monitoring techniques, seismic survey is considered as the most effective tool. To verify CO2 migration in the subsurface more effectively, seismic numerical simulation is an essential process. Furthermore, the efficiency of the seismic migration techniques should be investigated for various cases because numerical seismic simulation and migration test help us accurately interpret CO2 migration. In this study, we apply the reverse-time migration and Kirchhoff migration to synthetic seismic monitoring data generated for the simplified model based on the geological structures of Ulleung basin in Korea. Synthetic seismic monitoring data are generated for various cases of CO2 migration in the subsurface. From the seismic migration images, we can investigate CO2 diffusion patterns indirectly. From seismic monitoring simulation, it is noted that while the reverse-time migration generates clear subsurface images when subsurface structures are steeply dipping, Kirchhoff migration has an advantage in imaging horizontal-layered structures such as depositional sediments appearing in the continental shelf. The reverse-time migration and Kirchhoff migration present reliable subsurface images for the potential site characterized by stratigraphical traps. In case of

  20. Fisetin inhibits migration and invasion of human cervical cancer cells by down-regulating urokinase plasminogen activator expression through suppressing the p38 MAPK-dependent NF-κB signaling pathway.

    PubMed

    Chou, Ruey-Hwang; Hsieh, Shu-Ching; Yu, Yung-Luen; Huang, Min-Hsien; Huang, Yi-Chang; Hsieh, Yi-Hsien

    2013-01-01

    Fisetin (3,3',4',7-tetrahydroxyflavone), a naturally occurring flavonoid, has been reported to inhibit proliferation and induce apoptosis in several cancer types. However, its effect on the anti-metastatic potential of cervical cancer cells remains unclear. In the present study, we found that fisetin inhibits the invasion and migration of cervical cancer cells. The expression and activity of urokinase plasminogen activator (uPA) was significantly suppressed by fisetin in a dose-dependent manner. We also demonstrated that fisetin reduces the phosphorylation of p38 MAPK, but not that of ERK1/2, JNK1/2, or AKT. Addition of a p38 MAPK inhibitor, SB203580, further enhanced the inhibitory effect of fisetin on the expression and activity of uPA and the invasion and motility in cervical cancer cells. Fisetin suppressed the TPA (tetradecanoylphorbol-13-acetate)-induced activation of p38 MAPK and uPA, and inhibited the TPA-enhanced migratory and invasive abilities. Furthermore, the promoter activity of the uPA gene was dramatically repressed by fisetin, which disrupted the nuclear translocation of NF-κB and its binding amount on the promoter of the uPA gene, and these suppressive effects could be further enhanced by SB203580. This study provides strong evidence for the molecular mechanism of fisetin in inhibiting the aggressive phenotypes by repression of uPA via interruption of p38 MAPK-dependent NF-κB signaling pathway in cervical cancer cells and thus contributes insight to the potential of using fisetin as a therapeutic strategy against cervical cancer by inhibiting migration and invasion.

  1. Fisetin Inhibits Migration and Invasion of Human Cervical Cancer Cells by Down-Regulating Urokinase Plasminogen Activator Expression through Suppressing the p38 MAPK-Dependent NF-κB Signaling Pathway

    PubMed Central

    Chou, Ruey-Hwang; Hsieh, Shu-Ching; Yu, Yung-Luen; Huang, Min-Hsien; Huang, Yi-Chang; Hsieh, Yi-Hsien

    2013-01-01

    Fisetin (3,3’,4’,7-tetrahydroxyflavone), a naturally occurring flavonoid, has been reported to inhibit proliferation and induce apoptosis in several cancer types. However, its effect on the anti-metastatic potential of cervical cancer cells remains unclear. In the present study, we found that fisetin inhibits the invasion and migration of cervical cancer cells. The expression and activity of urokinase plasminogen activator (uPA) was significantly suppressed by fisetin in a dose-dependent manner. We also demonstrated that fisetin reduces the phosphorylation of p38 MAPK, but not that of ERK1/2, JNK1/2, or AKT. Addition of a p38 MAPK inhibitor, SB203580, further enhanced the inhibitory effect of fisetin on the expression and activity of uPA and the invasion and motility in cervical cancer cells. Fisetin suppressed the TPA (tetradecanoylphorbol-13-acetate)-induced activation of p38 MAPK and uPA, and inhibited the TPA-enhanced migratory and invasive abilities. Furthermore, the promoter activity of the uPA gene was dramatically repressed by fisetin, which disrupted the nuclear translocation of NF-κB and its binding amount on the promoter of the uPA gene, and these suppressive effects could be further enhanced by SB203580. This study provides strong evidence for the molecular mechanism of fisetin in inhibiting the aggressive phenotypes by repression of uPA via interruption of p38 MAPK-dependent NF-κB signaling pathway in cervical cancer cells and thus contributes insight to the potential of using fisetin as a therapeutic strategy against cervical cancer by inhibiting migration and invasion. PMID:23940799

  2. IDH1 R132H Mutation Enhances Cell Migration by Activating AKT-mTOR Signaling Pathway, but Sensitizes Cells to 5-FU Treatment as NADPH and GSH Are Reduced

    PubMed Central

    Qiu, Jiangdong; Huang, Keting; Wu, Mindan; Xia, Chunlin

    2017-01-01

    Aim of study Mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) gene were recently discovered in vast majority of World Health Organization (WHO) grade II/III gliomas. This study is to understand the effects of IDH1 R132H mutation in gliomagenesis and to develop new strategies to treat glioma with IDH1 R132H mutation. Materials and methods Over expression of IDH1 R132H in U87MG cells was done by transfecting cells with IDH1 R132H plasmid. MTT assay, scratch repair assay and western blot were performed to study effects of IDH1 R132H mutation on cell proliferation, migration, regulating AKT-mTOR signaling pathway and cell death respectively. NADP+/NADPH and GSH quantification assays were performed to evaluate effects of IDH1 R132H mutation on the production of antioxidant NADPH and GSH. Results We found that over expression of IDH1 R132H mutation decreased cell proliferation consistent with previous reports; however, it increased cell migration and enhanced AKT-mTOR signaling pathway activation. Mutations in isocitrate dehydrogenase (IDH) 1 also change the function of the enzymes and cause them to produce 2-hydroxyglutarate and not produce NADPH. We tested the level of NADPH and GSH and demonstrated that IDH1 R132H mutant stable cells had significantly low NADPH and GSH level compared to control or IDH1 wild type stable cells. The reduced antioxidants (NADPH and GSH) sensitized U87MG cells with IDH R132H mutant to 5-FU treatment. Conclusion Our study highlights the important role of IHD1 R132H mutant in up- regulating AKT-mTOR signaling pathway and enhancing cell migration. Furthermore, we demonstrate that IDH1 R132H mutation affects cellular redox status and sensitizes gliomas cells with IDH1 R132H mutation to 5FU treatment. PMID:28052098

  3. Tetrandrine inhibits migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes through down-regulating the expressions of Rac1, Cdc42, and RhoA GTPases and activation of the PI3K/Akt and JNK signaling pathways.

    PubMed

    Lv, Qi; Zhu, Xian-Yang; Xia, Yu-Feng; Dai, Yue; Wei, Zhi-Feng

    2015-11-01

    Tetrandrine (Tet), the main active constituent of Stephania tetrandra root, has been demonstrated to alleviate adjuvant-induced arthritis in rats. The present study was designed to investigate the effects of Tet on the migration and invasion of rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) and explore the underlying mechanisms. By using cultures of primary FLS isolated from synoviums of RA patients and cell line MH7A, Tet (0.3, 1 μmol·L(-1)) was proven to significantly impede migration and invasion of RA-FLS, but not cell proliferation. Tet also greatly reduced the activation and expressions of matrix degrading enzymes MMP-2/9, the expression of F-actin and the activation of FAK, which controlled the morphologic changes in migration process of FLS. To identify the key signaling pathways by which Tet exerts anti-migration effect, the specific inhibitors of multiple signaling pathways LY294002, Triciribine, SP600125, U0126, SB203580, and PDTC (against PI3K, Akt, JNK, ERK, p38 MAPK and NF-κB-p65, respectively) were used. Among them, LY294002, Triciribine, and SP600125 were shown to obviously inhibit the migration of MH7A cells. Consistently, Tet was able to down-regulate the activation of Akt and JNK as demonstrated by Western blotting assay. Moreover, Tet could reduce the expressions of migration-related proteins Rho GTPases Rac1, Cdc42, and RhoA in MH7A cells. In conclusion, Tet can impede the migration and invasion of RA-FLS, which provides a plausible explanation for its protective effect on RA. The underlying mechanisms involve the reduction of the expressions of Rac1, Cdc42, and RhoA, inhibition of the activation of Akt and JNK, and subsequent down-regulation of activation and/or expressions of MMP-2/9, F-actin, and FAK.

  4. Brain Migration Revisited

    ERIC Educational Resources Information Center

    Vinokur, Annie

    2006-01-01

    The "brain drain/brain gain" debate has been going on for the past 40 years, with irresolvable theoretical disputes and unenforceable policy recommendations that economists commonly ascribe to the lack of reliable empirical data. The recent report of the World Bank, "International migration, remittances and the brain drain", documents the…

  5. [Internal migration in Tanzania].

    PubMed

    Banyikwa, W F

    1982-01-01

    A general survey of population distribution in Tanzania is first presented using data from censuses taken between 1948 and 1979. Variations in distribution patterns are identified and discussed. The author then considers both spontaneous and planned internal migration trends and the factors affecting them. The effects of the official policy to resettle the rural population in larger villages are considered. (summary in ENG, RUS)

  6. Do downy woodpeckers migrate?

    USGS Publications Warehouse

    Browning, M.R.

    1995-01-01

    Seasonal movement and migration of Downy Woodpeckers (Picoides pubescens) are indicated in several sources in the literature. Analyses of 3784 recoveries of banded birds, with other data, indicate that the species is resident, and that movements of a few individuals may indicate dispersal.

  7. Nitric oxide regulates neutrophil migration through microparticle formation.

    PubMed

    Nolan, Sarah; Dixon, Rachel; Norman, Keith; Hellewell, Paul; Ridger, Victoria

    2008-01-01

    The role of nitric oxide (NO) in regulating neutrophil migration has been investigated. Human neutrophil migration to interleukin (IL)-8 (1 nmol/L) was measured after a 1-hour incubation using a 96-well chemotaxis plate assay. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester (L-NAME) significantly (P < 0.001) enhanced IL-8-induced migration by up to 45%. Anti-CD18 significantly (P < 0.001) inhibited both IL-8-induced and L-NAME enhanced migration. Antibodies to L-selectin or PSGL-1 had no effect on IL-8-induced migration but prevented the increased migration to IL-8 induced by L-NAME. L-NAME induced generation of neutrophil-derived microparticles that was significantly (P < 0.01) greater than untreated neutrophils or D-NAME. This microparticle formation was dependent on calpain activity and superoxide production. Only microparticles from L-NAME and not untreated or D-NAME-treated neutrophils induced a significant (P < 0.01) increase in IL-8-induced migration and transendothelial migration. Pretreatment of microparticles with antibodies to L-selectin (DREG-200) or PSGL-1 (PL-1) significantly (P < 0.001) inhibited this effect. The ability of L-NAME-induced microparticles to enhance migration was found to be dependent on the number of microparticles produced and not an increase in microparticle surface L-selectin or PSGL-1 expression. These data show that NO can modulate neutrophil migration by regulating microparticle formation.

  8. Comparative Survival Study (CSS) of Hatchery PIT-tagged Spring/Summer Chinook; Migration Years 1997-2000 Mark/Recapture Activities and Bootstrap Analysis, 2002 Annual Report.

    SciTech Connect

    Berggren Thomas J.; Franzoni, Henry; Basham, Larry R.

    2005-04-01

    The Comparative Survival Study (CSS) was initiated in 1996 as a multi-year program of the fishery agencies and tribes to estimate survival rates over different life stages for spring and summer chinook (hereafter, chinook) produced in major hatcheries in the Snake River basin and from selected hatcheries in the lower Columbia River. Much of the information evaluated in the CSS is derived from fish tagged with Passive Integrated Transponder (PIT) tags. A comparison of survival rates of chinook marked in two different regions (which differ in the number of dams chinook have to migrate through) provides insight into the effects of the Snake/Columbia hydroelectric system (hydrosystem). The CSS also compares the smolt-to-adult survival rates (SARs) for Snake River chinook that were transported versus those that migrated in-river to below Bonneville Dam. Additional comparisons can be made within in-river experiences as well comparison between the different collector projects from which smolts are transported. CSS also compares these survival rates for wild Snake River spring and summer chinook. These comparisons generate information regarding the relative effects of the current management actions used to recover this listed species. Scientists and managers have recently emphasized the importance of delayed hydrosystem mortality to long-term management decisions. Delayed hydrosystem mortality may be related to the smolts experience in the Federal Columbia River Power System, and could occur for both smolts that migrate in-river and smolts that are transported. The CSS PIT tag information on in-river survival rates and smolt-to-adult survival rates (SARs) of transported and in-river fish are relevant to estimation of ''D'', which partially describes delayed hydrosystem mortality. The parameter D is the differential survival rate of transported fish relative to fish that migrate in-river, as measured from below Bonneville Dam to adults returning to Lower Granite Dam. When D

  9. Migration of epithelial cells on laminins: RhoA antagonizes directionally persistent migration.

    PubMed

    Zhang, Zhigang; Chometon, Gretel; Wen, Tingting; Qu, Haiyan; Mauch, Cornelia; Krieg, Thomas; Aumailley, Monique

    2011-01-01

    Spatial and temporal expression of laminin isoforms is assumed to provide specific local information to neighboring cells. Here, we report the remarkably selective presence of LM-111 at the very tip of hair follicles where LM-332 is absent, suggesting that epithelial cells lining the dermal-epidermal junction at this location may receive different signals from the two laminins. This hypothesis was tested in vitro by characterizing with functional and molecular assays the comportment of keratinocytes exposed to LM-111 and LM-332. The two laminins induced morphologically distinct focal adhesions, and LM-332, but not LM-111, elicited persistent migration of keratinocytes. The different impact on cellular behavior was associated with distinct activation patterns of Rho GTPases and other signaling intermediates. In particular, while LM-111 triggered a robust activation of Cdc42, LM-332 provoked a strong and sustained activation of FAK. Interestingly, activation of Rac1 was necessary but not sufficient to promote migration because there was no directed migration on LM-111 despite Rac1 activation. In contrast, RhoA antagonized directional migration, since silencing of RhoA by RNA interference boosted unidirectional migration on LM-332. Molecular analysis of the role of RhoA strongly suggested that the mechanisms involve disassembly of cell-cell contacts, loss of the cortical actin network, mobilization of α6β4 integrin out of stable adhesions, and displacement of the integrin from its association with the insoluble pool of intermediate filaments.

  10. Constitutive activation of p38 and ERK1/2 MAPKs in epithelial cells of myasthenic thymus leads to IL-6 and RANTES overexpression: effects on survival and migration of peripheral T and B cells.

    PubMed

    Colombara, Michaela; Antonini, Valeria; Riviera, Anna Pia; Mainiero, Fabrizio; Strippoli, Raffaele; Merola, Marcello; Fracasso, Giulio; Poffe, Ornella; Brutti, Nadia; Tridente, Giuseppe; Colombatti, Marco; Ramarli, Dunia

    2005-11-15

    Myasthenia gravis (MG) is an autoimmune disease of neuromuscular junctions where thymus plays a pathogenetic role. Thymectomy benefits patients, and thymic hyperplasia, a lymphoid infiltration of perivascular spaces becoming site of autoantibody production, is recurrently observed. Cytokines and chemokines, produced by thymic epithelium and supporting survival and migration of T and B cells, are likely to be of great relevance in pathogenesis of thymic hyperplasia. In thymic epithelial cell (TEC) cultures derived "in vitro" from normal or hyperplastic age-matched MG thymuses, we demonstrate by gene profiling analysis that MG-TEC basally overexpress genes coding for p38 and ERK1/2 MAPKs and for components of their signaling pathways. Immunoblotting experiments confirmed that p38 and ERK1/2 proteins were overexpressed in MG-TEC and, in addition, constitutively activated. Pharmacological blockage with specific inhibitors confirmed their role in the control of IL-6 and RANTES gene expression. According to our results, IL-6 and RANTES levels were abnormally augmented in MG-TEC, either basally or upon induction by adhesion-related stimuli. The finding that IL-6 and RANTES modulate, respectively, survival and migration of peripheral lymphocytes of myasthenic patients point to MAPK transcriptional and posttranscriptional abnormalities of MG-TEC as a key step in the pathological remodelling of myasthenic thymus.

  11. Macrophage Migration Inhibition Studies with Cells from Mice Vaccinated with Cell Walls of Mycobacterium bovis BCG: Relationship Between Inhibitory Activity of Lung Cells and Resistance to Airborne Challenge with Mycobacterium tuberculosis H37Rv.

    PubMed

    Yamamoto, K; Anacker, R L; Ribi, E

    1970-06-01

    In an effort to evaluate the role of delayed hypersensitivity in acquired resistance of mice to airborne infection with Mycobacterium tuberculosis H37Rv, the ability of lung and peritoneal cells from mice vaccinated in various ways with mycobacterial fractions or with M. bovis BCG to inhibit, in the presence of purified protein derivative, in vitro migration of normal peritoneal cells was determined. The degree of inhibition induced by lung cells was correlated with immunity, but that induced by peritoneal cells could not be associated with enhanced resistance. Live BCG given intravenously to mice stimulated greater resistance to infection and inhibitory activity of lung cells than did live BCG given subcutaneously. Vaccines with a protective index greater than 1 also induced a significant increase in lung weight. Although a correlation between ability of lung cells to inhibit cell migration and acquired resistance of the host to airborne infection with H37Rv was demonstrated, the data do not exclude the possibility that the two phenomena are independent responses to the immunologically complex mycobacterial antigens.

  12. Migrating Oligodendrocyte Progenitor Cells Swell Prior to Soma Dislocation

    PubMed Central

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

    2013-01-01

    The migration of oligodendrocyte progenitor cells (OPCs) to the white matter is an indispensable requirement for an intact brain function. The mechanism of cell migration in general is not yet completely understood. Nevertheless, evidence is accumulating that besides the coordinated rearrangement of the cytoskeleton, a finetuned interplay of ion and water fluxes across the cell membrane is essential for cell migration. One part of a genera