WorldWideScience

Sample records for cellular motile functions

  1. Cellular mechanics and motility

    Science.gov (United States)

    Hénon, Sylvie; Sykes, Cécile

    2015-10-01

    The term motility defines the movement of a living organism. One widely known example is the motility of sperm cells, or the one of flagellar bacteria. The propulsive element of such organisms is a cilium(or flagellum) that beats. Although cells in our tissues do not have a flagellum in general, they are still able to move, as we will discover in this chapter. In fact, in both cases of movement, with or without a flagellum, cell motility is due to a dynamic re-arrangement of polymers inside the cell. Let us first have a closer look at the propulsion mechanism in the case of a flagellum or a cilium, which is the best known, but also the simplest, and which will help us to define the hydrodynamic general conditions of cell movement. A flagellum is sustained by cellular polymers arranged in semi-flexible bundles and flagellar beating generates cell displacement. These polymers or filaments are part of the cellular skeleton, or "cytoskeleton", which is, in this case, external to the cellular main body of the organism. In fact, bacteria move in a hydrodynamic regime in which viscosity dominates over inertia. The system is thus in a hydrodynamic regime of low Reynolds number (Box 5.1), which is nearly exclusively the case in all cell movements. Bacteria and their propulsion mode by flagella beating are our unicellular ancestors 3.5 billion years ago. Since then, we have evolved to form pluricellular organisms. However, to keep the ability of displacement, to heal our wounds for example, our cells lost their flagellum, since it was not optimal in a dense cell environment: cells are too close to each other to leave enough space for the flagella to accomplish propulsion. The cytoskeleton thus developed inside the cell body to ensure cell shape changes and movement, and also mechanical strength within a tissue. The cytoskeleton of our cells, like the polymers or filaments that sustain the flagellum, is also composed of semi-flexible filaments arranged in bundles, and also in

  2. Cellular Scale Anisotropic Topography Guides Schwann Cell Motility

    Science.gov (United States)

    Mitchel, Jennifer A.; Hoffman-Kim, Diane

    2011-01-01

    Directed migration of Schwann cells (SC) is critical for development and repair of the peripheral nervous system. Understanding aspects of motility specific to SC, along with SC response to engineered biomaterials, may inform strategies to enhance nerve regeneration. Rat SC were cultured on laminin-coated microgrooved poly(dimethyl siloxane) platforms that were flat or presented repeating cellular scale anisotropic topographical cues, 30 or 60 µm in width, and observed with timelapse microscopy. SC motion was directed parallel to the long axis of the topography on both the groove floor and the plateau, with accompanying differences in velocity and directional persistence in comparison to SC motion on flat substrates. In addition, feature dimension affected SC morphology, alignment, and directional persistence. Plateaus and groove floors presented distinct cues which promoted differential motility and variable interaction with the topographical features. SC on the plateau surfaces tended to have persistent interactions with the edge topography, while SC on the groove floors tended to have infrequent contact with the corners and walls. Our observations suggest the capacity of SC to be guided without continuous contact with a topographical cue. SC exhibited a range of distinct motile morphologies, characterized by their symmetry and number of extensions. Across all conditions, SC with a single extension traveled significantly faster than cells with more or no extensions. We conclude that SC motility is complex, where persistent motion requires cellular asymmetry, and that anisotropic topography with cellular scale features can direct SC motility. PMID:21949703

  3. Evaluation of Esophageal Motility Utilizing the Functional Lumen Imaging Probe.

    Science.gov (United States)

    Carlson, Dustin A; Kahrilas, Peter J; Lin, Zhiyue; Hirano, Ikuo; Gonsalves, Nirmala; Listernick, Zoe; Ritter, Katherine; Tye, Michael; Ponds, Fraukje A; Wong, Ian; Pandolfino, John E

    2016-12-01

    Esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis can be assessed with the functional lumen imaging probe (FLIP) during a sedated upper endoscopy. We aimed to describe esophageal motility assessment using FLIP topography in patients presenting with dysphagia. In all, 145 patients (aged 18-85 years, 54% female) with dysphagia that completed upper endoscopy with a 16-cm FLIP assembly and high-resolution manometry (HRM) were included. HRM was analyzed according to the Chicago Classification of esophageal motility disorders; major esophageal motility disorders were considered "abnormal". FLIP studies were analyzed using a customized program to calculate the EGJ-distensibility index (DI) and generate FLIP topography plots to identify esophageal contractility patterns. FLIP topography was considered "abnormal" if EGJ-DI was esophageal motility and 29 normal motility. In all, 17 (50%) had abnormal FLIP topography including 13 (37%) with abnormal EGJ-DI. FLIP topography provides a well-tolerated method for esophageal motility assessment (especially to identify achalasia) at the time of upper endoscopy. FLIP topography findings that are discordant with HRM may indicate otherwise undetected abnormalities of esophageal function, thus FLIP provides an alternative and complementary method to HRM for evaluation of non-obstructive dysphagia.

  4. Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease.

    Science.gov (United States)

    Lewis, Wesley R; Malarkey, Erik B; Tritschler, Douglas; Bower, Raqual; Pasek, Raymond C; Porath, Jonathan D; Birket, Susan E; Saunier, Sophie; Antignac, Corinne; Knowles, Michael R; Leigh, Margaret W; Zariwala, Maimoona A; Challa, Anil K; Kesterson, Robert A; Rowe, Steven M; Drummond, Iain A; Parant, John M; Hildebrandt, Friedhelm; Porter, Mary E; Yoder, Bradley K; Berbari, Nicolas F

    2016-07-01

    Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh) signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400). While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8). GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC) protein 4 (DRC4) where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR) to generate one of these human missense variants in

  5. Mutation of Growth Arrest Specific 8 Reveals a Role in Motile Cilia Function and Human Disease.

    Directory of Open Access Journals (Sweden)

    Wesley R Lewis

    2016-07-01

    Full Text Available Ciliopathies are genetic disorders arising from dysfunction of microtubule-based cellular appendages called cilia. Different cilia types possess distinct stereotypic microtubule doublet arrangements with non-motile or 'primary' cilia having a 9+0 and motile cilia have a 9+2 array of microtubule doublets. Primary cilia are critical sensory and signaling centers needed for normal mammalian development. Defects in their structure/function result in a spectrum of clinical and developmental pathologies including abnormal neural tube and limb patterning. Altered patterning phenotypes in the limb and neural tube are due to perturbations in the hedgehog (Hh signaling pathway. Motile cilia are important in fluid movement and defects in motility result in chronic respiratory infections, altered left-right asymmetry, and infertility. These features are the hallmarks of Primary Ciliary Dyskinesia (PCD, OMIM 244400. While mutations in several genes are associated with PCD in patients and animal models, the genetic lesion in many cases is unknown. We assessed the in vivo functions of Growth Arrest Specific 8 (GAS8. GAS8 shares strong sequence similarity with the Chlamydomonas Nexin-Dynein Regulatory Complex (NDRC protein 4 (DRC4 where it is needed for proper flagella motility. In mammalian cells, the GAS8 protein localizes not only to the microtubule axoneme of motile cilia, but also to the base of non-motile cilia. Gas8 was recently implicated in the Hh signaling pathway as a regulator of Smoothened trafficking into the cilium. Here, we generate the first mouse with a Gas8 mutation and show that it causes severe PCD phenotypes; however, there were no overt Hh pathway phenotypes. In addition, we identified two human patients with missense variants in Gas8. Rescue experiments in Chlamydomonas revealed a subtle defect in swim velocity compared to controls. Further experiments using CRISPR/Cas9 homology driven repair (HDR to generate one of these human missense

  6. Cellular Biophysics During Freezing of Rat and Mouse Sperm Predicts Post-thaw Motility1

    Science.gov (United States)

    Hagiwara, Mie; Choi, Jeung Hwan; Devireddy, Ramachandra V.; Roberts, Kenneth P.; Wolkers, Willem F.; Makhlouf, Antoine; Bischof, John C.

    2009-01-01

    Though cryopreservation of mouse sperm yields good survival and motility after thawing, cryopreservation of rat sperm remains a challenge. This study was designed to evaluate the biophysics (membrane permeability) of rat in comparison to mouse to better understand the cooling rate response that contributes to cryopreservation success or failure in these two sperm types. In order to extract subzero membrane hydraulic permeability in the presence of ice, a differential scanning calorimeter (DSC) method was used. By analyzing rat and mouse sperm frozen at 5°C/min and 20°C/min, heat release signatures characteristic of each sperm type were obtained and correlated to cellular dehydration. The dehydration response was then fit to a model of cellular water transport (dehydration) by adjusting cell-specific biophysical (membrane hydraulic permeability) parameters Lpg and ELp. A “combined fit” (to 5°C/min and 20°C/min data) for rat sperm in Biggers-Whitten-Whittingham media yielded Lpg = 0.007 μm min−1 atm−1 and ELp = 17.8 kcal/mol, and in egg yolk cryopreservation media yielded Lpg = 0.005 μm min−1 atm−1 and ELp = 14.3 kcal/mol. These parameters, especially the activation energy, were found to be lower than previously published parameters for mouse sperm. In addition, the biophysical responses in mouse and rat sperm were shown to depend on the constituents of the cryopreservation media, in particular egg yolk and glycerol. Using these parameters, optimal cooling rates for cryopreservation were predicted for each sperm based on a criteria of 5%–15% normalized cell water at −30°C during freezing in cryopreservation media. These predicted rates range from 53°C/min to 70°C/min and from 28°C/min to 36°C/min in rat and mouse, respectively. These predictions were validated by comparison to experimentally determined cryopreservation outcomes, in this case based on motility. Maximum motility was obtained with freezing rates between 50°C/min and 80

  7. Cellular biophysics during freezing of rat and mouse sperm predicts post-thaw motility.

    Science.gov (United States)

    Hagiwara, Mie; Choi, Jeung Hwan; Devireddy, Ramachandra V; Roberts, Kenneth P; Wolkers, Willem F; Makhlouf, Antoine; Bischof, John C

    2009-10-01

    Though cryopreservation of mouse sperm yields good survival and motility after thawing, cryopreservation of rat sperm remains a challenge. This study was designed to evaluate the biophysics (membrane permeability) of rat in comparison to mouse to better understand the cooling rate response that contributes to cryopreservation success or failure in these two sperm types. In order to extract subzero membrane hydraulic permeability in the presence of ice, a differential scanning calorimeter (DSC) method was used. By analyzing rat and mouse sperm frozen at 5 degrees C/min and 20 degrees C/min, heat release signatures characteristic of each sperm type were obtained and correlated to cellular dehydration. The dehydration response was then fit to a model of cellular water transport (dehydration) by adjusting cell-specific biophysical (membrane hydraulic permeability) parameters L(pg) and E(Lp). A "combined fit" (to 5 degrees C/min and 20 degrees C/min data) for rat sperm in Biggers-Whitten-Whittingham media yielded L(pg) = 0.007 microm min(-1) atm(-1) and E(Lp) = 17.8 kcal/mol, and in egg yolk cryopreservation media yielded L(pg) = 0.005 microm min(-1) atm(-1) and E(Lp) = 14.3 kcal/mol. These parameters, especially the activation energy, were found to be lower than previously published parameters for mouse sperm. In addition, the biophysical responses in mouse and rat sperm were shown to depend on the constituents of the cryopreservation media, in particular egg yolk and glycerol. Using these parameters, optimal cooling rates for cryopreservation were predicted for each sperm based on a criteria of 5%-15% normalized cell water at -30 degrees C during freezing in cryopreservation media. These predicted rates range from 53 degrees C/min to 70 degrees C/min and from 28 degrees C/min to 36 degrees C/min in rat and mouse, respectively. These predictions were validated by comparison to experimentally determined cryopreservation outcomes, in this case based on motility. Maximum

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

    Directory of Open Access Journals (Sweden)

    Assaf Zaritsky

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

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

    Science.gov (United States)

    Zaritsky, Assaf; Natan, Sari; Horev, Judith; Hecht, Inbal; Wolf, Lior; Ben-Jacob, Eshel; Tsarfaty, Ilan

    2011-01-01

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

  10. Functional Magnetic Resonance in the Evaluation of Oesophageal Motility Disorders

    Directory of Open Access Journals (Sweden)

    Francesco Covotta

    2011-01-01

    Our aim is to assess the role of fMRI as a technique to assess morphological and functional parameters of the esophagus in patients with esophageal motor disorders and in healthy controls. Subsequently, we assessed the diagnostic efficiency of fMRI in comparison to videofluoroscopic and manometric findings in the investigation of patients with esophageal motor disorders. Considering that fMRI was shown to offer valuable information on bolus transit and on the caliber of the esophagus, variations of these two parameters in the different types of esophageal motor alterations have been assessed. fMRI, compared to manometry and videofluoroscopy, showed that a deranged or absent peristalsis is significantly associated with slower transit time and with increased esophageal diameter. Although further studies are needed, fMRI represents a promising noninvasive technique for the integrated functional and morphological evaluation of esophageal motility disorders.

  11. Functional proteomic analysis reveals the involvement of KIAA1199 in breast cancer growth, motility and invasiveness

    International Nuclear Information System (INIS)

    Jami, Mohammad-Saeid; Huang, Xin; Peng, Hong; Fu, Kai; Li, Yan; Singh, Rakesh K; Ding, Shi-Jian; Hou, Jinxuan; Liu, Miao; Varney, Michelle L; Hassan, Hesham; Dong, Jixin; Geng, Liying; Wang, Jing; Yu, Fang

    2014-01-01

    KIAA1199 is a recently identified novel gene that is up-regulated in human cancer with poor survival. Our proteomic study on signaling polarity in chemotactic cells revealed KIAA1199 as a novel protein target that may be involved in cellular chemotaxis and motility. In the present study, we examined the functional significance of KIAA1199 expression in breast cancer growth, motility and invasiveness. We validated the previous microarray observation by tissue microarray immunohistochemistry using a TMA slide containing 12 breast tumor tissue cores and 12 corresponding normal tissues. We performed the shRNA-mediated knockdown of KIAA1199 in MDA-MB-231 and HS578T cells to study the role of this protein in cell proliferation, migration and apoptosis in vitro. We studied the effects of KIAA1199 knockdown in vivo in two groups of mice (n = 5). We carried out the SILAC LC-MS/MS based proteomic studies on the involvement of KIAA1199 in breast cancer. KIAA1199 mRNA and protein was significantly overexpressed in breast tumor specimens and cell lines as compared with non-neoplastic breast tissues from large-scale microarray and studies of breast cancer cell lines and tumors. To gain deeper insights into the novel role of KIAA1199 in breast cancer, we modulated KIAA1199 expression using shRNA-mediated knockdown in two breast cancer cell lines (MDA-MB-231 and HS578T), expressing higher levels of KIAA1199. The KIAA1199 knockdown cells showed reduced motility and cell proliferation in vitro. Moreover, when the knockdown cells were injected into the mammary fat pads of female athymic nude mice, there was a significant decrease in tumor incidence and growth. In addition, quantitative proteomic analysis revealed that knockdown of KIAA1199 in breast cancer (MDA-MB-231) cells affected a broad range of cellular functions including apoptosis, metabolism and cell motility. Our findings indicate that KIAA1199 may play an important role in breast tumor growth and invasiveness, and that it

  12. Self-organization of engineered epithelial tubules by differential cellular motility

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Hidetoshi; Gjorevski, Nikolce; Inman, Jamie L; Bissell, Mina J; Nelson, Celeste M

    2009-02-04

    Patterning of developing tissues arises from a number of mechanisms, including cell shape change, cell proliferation, and cell sorting from differential cohesion or tension. Here, we reveal that differences in cell motility can also lead to cell sorting within tissues. Using mosaic engineered mammary epithelial tubules, we found that cells sorted depending on their expression level of the membrane-anchored collagenase matrix metalloproteinase (MMP)-14. These rearrangements were independent of the catalytic activity of MMP14 but absolutely required the hemopexin domain. We describe a signaling cascade downstream of MMP14 through Rho kinase that allows cells to sort within the model tissues. Cell speed and persistence time were enhanced by MMP14 expression, but only the latter motility parameter was required for sorting. These results indicate that differential directional persistence can give rise to patterns within model developing tissues.

  13. Vagal activation by sham feeding improves gastric motility in functional dyspepsia.

    Science.gov (United States)

    Lunding, J A; Nordström, L M; Haukelid, A-O; Gilja, O H; Berstad, A; Hausken, T

    2008-06-01

    Antral hypomotility and impaired gastric accommodation in patients with functional dyspepsia have been ascribed to vagal dysfunction. We investigated whether vagal stimulation by sham feeding would improve meal-induced gastric motor function in these patients. Fourteen healthy volunteers and 14 functional dyspepsia patients underwent a drink test twice, once with and once without simultaneous sham feeding. After ingesting 500 mL clear meat soup (20 kcal, 37 degrees C) in 4 min, sham feeding was performed for 10 min by chewing a sugar-containing chewing gum while spitting out saliva. Using two- and three-dimensional ultrasound, antral motility index (contraction amplitude x frequency) and intragastric volumes were estimated. Without sham feeding, functional dyspepsia patients had lower motility index than healthy volunteers (area under curve 8.0 +/- 1.2 vs 4.4 +/- 1.0 min(-1), P = 0.04). In functional dyspepsia patients, but not in healthy volunteers, motility index increased and intragastric volume tended to increase by sham feeding (P = 0.04 and P = 0.06 respectively). The change in motility index was negatively correlated to the change in pain score (r = -0.59, P = 0.007). In functional dyspepsia patients, vagal stimulation by sham feeding improves antral motility in response to a soup meal. The result supports the view that impaired vagal stimulation is implicated in the pathogenesis of gastric motility disturbances in functional dyspepsia.

  14. Evaluation of esophageal motility utilizing the functional lumen imaging probe (FLIP)

    Science.gov (United States)

    Carlson, Dustin A.; Kahrilas, Peter J.; Lin, Zhiyue; Hirano, Ikuo; Gonsalves, Nirmala; Listernick, Zoe; Ritter, Katherine; Tye, Michael; Ponds, Fraukje A.; Wong, Ian; Pandolfino, John E.

    2016-01-01

    Background Esophagogastric junction (EGJ) distensibility and distension-mediated peristalsis can be assessed with the functional lumen imaging probe (FLIP) during a sedated upper endoscopy. We aimed to describe esophageal motility assessment using FLIP topography in patients presenting with dysphagia. Methods 145 patients (ages 18 – 85, 54% female) with dysphagia that completed upper endoscopy with a 16-cm FLIP assembly and high-resolution manometry (HRM) were included. HRM was analyzed according to the Chicago Classification of esophageal motility disorders; major esophageal motility disorders were considered ‘abnormal’. FLIP studies were analyzed using a customized program to calculate the EGJ-distensibility index (DI) and generate FLIP topography plots to identify esophageal contractility patterns. FLIP topography was considered ‘abnormal’ if EGJ-DI was esophageal motility and 29 normal motility. 17 (50%) had abnormal FLIP topography including 13 (37%) with abnormal EGJ-DI. Conclusions FLIP topography provides a well-tolerated method for esophageal motility assessment (especially to identify achalasia) at the time of upper endoscopy. FLIP topography findings that are discordant with HRM may indicate otherwise undetected abnormalities of esophageal function, thus FLIP provides an alternative and complementary method to HRM for evaluation of non-obstructive dysphagia. PMID:27725650

  15. Lactate and Pyruvate Are Major Sources of Energy for Stallion Sperm with Dose Effects on Mitochondrial Function, Motility, and ROS Production.

    Science.gov (United States)

    Darr, Christa R; Varner, Dickson D; Teague, Sheila; Cortopassi, Gino A; Datta, Sandipan; Meyers, Stuart A

    2016-08-01

    Stallion sperm rely primarily on oxidative phosphorylation for production of ATP used in sperm motility and metabolism. The objective of the study was to identify which substrates included in Biggers, Whitten, and Whittingham (BWW) media are key to optimal mitochondrial function through measurements of sperm motility parameters, mitochondrial oxygen consumption, and cellular reactive oxygen species (ROS) production. It was expected that mitochondrial substrates, pyruvate and lactate, would support sperm motility and mitochondrial function better than the glycolytic substrate, glucose, due to direct utilization within the mitochondria. Measurements were performed after incubation in modified BWW media with varying concentrations of lactate, pyruvate, and glucose. The effects of media and duration of incubation on sperm motility, ROS production, and oxygen consumption were determined using a linear mixed-effects model. Duplicate ejaculates from four stallions were used in three separate experiments to determine the effects of substrate availability and concentration on sperm motility and mitochondrial function and the relationship of oxygen consumption with cellular ROS production. The present results indicate that lactate and pyruvate are the most important sources of energy for stallion sperm motility and velocity, and elicit a dose-dependent response. Additionally, lactate and pyruvate are ideal for maximal mitochondrial function, as sperm in these media operate at a very high level of their bioenergetic capability due to the high rate of energy metabolism. Moreover, we found that addition of glucose to the media is not necessary for short-term storage of equine sperm, and may even result in reduction of mitochondrial function. Finally, we have confirmed that ROS production can be the result of mitochondrial dysfunction as well as intense mitochondrial activity. © 2016 by the Society for the Study of Reproduction, Inc.

  16. Their function on angiogenesis and cellular signalling

    Indian Academy of Sciences (India)

    Copper, although known as a micronutrient, has a pivotal role in modulating the cellular metabolism. Many studieshave reported the role of copper in angiogenesis. Copper chaperones are intracellular proteins that mediate coppertrafficking to various cell organelles. However, the role and function of copper chaperones in ...

  17. Functional Magnetic Resonance in the Evaluation of Oesophageal Motility Disorders

    OpenAIRE

    Covotta, Francesco; Piretta, Luca; Badiali, Danilo; Laghi, Andrea; Biondi, Tommaso; Corazziari, Enrico S.; Panebianco, Valeria

    2011-01-01

    Functional magnetic resonance imaging (fMRI) has been recently proposed for the evaluation of the esophagus. Our aim is to assess the role of fMRI as a technique to assess morphological and functional parameters of the esophagus in patients with esophageal motor disorders and in healthy controls. Subsequently, we assessed the diagnostic efficiency of fMRI in comparison to videofluoroscopic and manometric findings in the investigation of patients with esophageal motor disorders. Considering...

  18. Mechanisms and cellular functions of intramembrane proteases.

    Science.gov (United States)

    Urban, Siniša

    2013-12-01

    The turn of the millennium coincided with the branding of a fundamentally different class of enzyme - proteases that reside immersed inside the membrane. This new field was the convergence of completely separate lines of research focused on cholesterol homeostasis, Alzheimer's disease, and developmental genetics. None intended their ultimate path, but soon became a richly-integrated fabric for an entirely new field: regulated intramembrane proteolysis. Our aim in this Special Issue is to focus on the ancient and nearly ubiquitous enzymes that catalyze this unexpected yet important reaction. The pace of progress has been dramatic, resulting in a rapidly-expanding universe of known cellular functions, and a paradigm shift in the biochemical understanding of these once heretical enzymes. More recently, the first therapeutic successes have been attained by targeting an intramembrane protease. We consider these advances and identify oncoming opportunities in four parts: growing spectra of cellular roles, insights into biochemical mechanisms, therapeutic strategies, and newly-emerging topics. Recent studies also expose challenges for the future, including non-linear relationships between substrate identification and physiological functions, and the need for potent and specific, not broad-class, inhibitors. © 2013.

  19. A model of the effects of cancer cell motility and cellular adhesion properties on tumour-immune dynamics.

    Science.gov (United States)

    Frascoli, Federico; Flood, Emelie; Kim, Peter S

    2017-06-01

    We present a three-dimensional model simulating the dynamics of an anti-cancer T-cell response against a small, avascular, early-stage tumour. Interactions at the tumour site are accounted for using an agent-based model (ABM), while immune cell dynamics in the lymph node are modelled as a system of delay differential equations (DDEs). We combine these separate approaches into a two-compartment hybrid ABM-DDE system to capture the T-cell response against the tumour. In the ABM at the tumour site, movement of tumour cells is modelled using effective physical forces with a specific focus on cell-to-cell adhesion properties and varying levels of tumour cell motility, thus taking into account the ability of cancer cells to spread and form clusters. We consider the effectiveness of the immune response over a range of parameters pertaining to tumour cell motility, cell-to-cell adhesion strength and growth rate. We also investigate the dependence of outcomes on the distribution of tumour cells. Low tumour cell motility is generally a good indicator for successful tumour eradication before relapse, while high motility leads, almost invariably, to relapse and tumour escape. In general, the effect of cell-to-cell adhesion on prognosis is dependent on the level of tumour cell motility, with an often unpredictable cross influence between adhesion and motility, which can lead to counterintuitive effects. In terms of overall tumour shape and structure, the spatial distribution of cancer cells in clusters of various sizes has shown to be strongly related to the likelihood of extinction. © The authors 2016. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  20. Campylobacter jejuni CsrA complements an Escherichia coli csrA mutation for the regulation of biofilm formation, motility and cellular morphology but not glycogen accumulation

    Science.gov (United States)

    2012-01-01

    Background Although Campylobacter jejuni is consistently ranked as one of the leading causes of bacterial diarrhea worldwide, the mechanisms by which C. jejuni causes disease and how they are regulated have yet to be clearly defined. The global regulator, CsrA, has been well characterized in several bacterial genera and is known to regulate a number of independent pathways via a post transcriptional mechanism, but remains relatively uncharacterized in the genus Campylobacter. Previously, we reported data illustrating the requirement for CsrA in several virulence related phenotypes of C. jejuni strain 81–176, indicating that the Csr pathway is important for Campylobacter pathogenesis. Results We compared the Escherichia coli and C. jejuni orthologs of CsrA and characterized the ability of the C. jejuni CsrA protein to functionally complement an E. coli csrA mutant. Phylogenetic comparison of E. coli CsrA to orthologs from several pathogenic bacteria demonstrated variability in C. jejuni CsrA relative to the known RNA binding domains of E. coli CsrA and in several amino acids reported to be involved in E. coli CsrA-mediated gene regulation. When expressed in an E. coli csrA mutant, C. jejuni CsrA succeeded in recovering defects in motility, biofilm formation, and cellular morphology; however, it failed to return excess glycogen accumulation to wild type levels. Conclusions These findings suggest that C. jejuni CsrA is capable of efficiently binding some E. coli CsrA binding sites, but not others, and provide insight into the biochemistry of C. jejuni CsrA. PMID:23051923

  1. Agonists for G-protein-coupled receptor 84 (GPR84) alter cellular morphology and motility but do not induce pro-inflammatory responses in microglia.

    Science.gov (United States)

    Wei, Li; Tokizane, Kyohei; Konishi, Hiroyuki; Yu, Hua-Rong; Kiyama, Hiroshi

    2017-10-03

    Several G-protein-coupled receptors (GPCRs) have been shown to be important signaling mediators between neurons and glia. In our previous screening for identification of nerve injury-associated GPCRs, G-protein-coupled receptor 84 (GPR84) mRNA showed the highest up-regulation by microglia after nerve injury. GPR84 is a pro-inflammatory receptor of macrophages in a neuropathic pain mouse model, yet its function in resident microglia in the central nervous system is poorly understood. We used endogenous, natural, and surrogate agonists for GPR84 (capric acid, embelin, and 6-OAU, respectively) and examined their effect on mouse primary cultured microglia in vitro. 6-n-Octylaminouracil (6-OAU), embelin, and capric acid rapidly induced membrane ruffling and motility in cultured microglia obtained from C57BL/6 mice, although these agonists failed to promote microglial pro-inflammatory cytokine expression. Concomitantly, 6-OAU suppressed forskolin-induced increase of cAMP in cultured microglia. Pertussis toxin, an inhibitor of Gi-coupled signaling, completely suppressed 6-OAU-induced microglial membrane ruffling and motility. In contrast, no 6-OAU-induced microglial membrane ruffling and motility was observed in microglia from DBA/2 mice, a mouse strain that does not express functional GPR84 protein due to endogenous nonsense mutation of the GPR84 gene. GPR84 mediated signaling causes microglial motility and membrane ruffling but does not promote pro-inflammatory responses. As GPR84 is a known receptor for medium-chain fatty acids, those released from damaged brain cells may be involved in the enhancement of microglial motility through GPR84 after neuronal injury.

  2. Visualization and quantification of large bowel motility with functional cine-MRI

    International Nuclear Information System (INIS)

    Buhmann, S.; Wielage, C.; Fischer, T.; Reiser, M.; Lienemann, A.; Kirchhoff, C.; Mussack, T.

    2005-01-01

    Purpose: to develop and evaluate a method to visualize and quantify large bowel motility using functional cine MRI. Methods: fifteen healthy individuals (8males, 7 females, 20 to 45 years old) with no history or present symptoms of bowel disorders were enrolled in a functional cine MRI examination at 6 a. m. after a starving phase for at least eight hours before and after oral administration of Senna tea (mild stimulating purgative). Two consecutive sets of repeated measurements of the entire abdomen were performed using a 1.5T MRI system with coronal T2-weighted HASTE sequences anatomically adjusted to the course of the large bowel. A navigator technique was used for respiratory gating at the level of the right dorsal diaphragm. The changes in diameter (given in cm) were measured at 5 different locations of the ascending (AC), transverse (TC) and descending colon (DC), and assessed as parameters for the bowel motility. Results: the mean values as a statistical measure for large bowel relaxation were determined. Before ingestion of Senna tea, the mean diameter measured 3.41 cm (ascending colon), 3 cm (transverse colon) and 2.67 cm (descending colon). After the ingestion of Senna tea, the mean diameter increased to 3.69 cm (ascending colon) to 3.4 cm (transverse colon) and to 2.9 cm (descending colon). A statistically significant difference was demonstrated with the Wilcoxon test (level of confidence 0.05). For the determination of dynamic increase, the changes of the statistical scatter amplitude to the mean value were expressed as percentage before and after the ingestion of Senna tea. Thereby, an increase in variation and dynamic range was detected for the AC (112.9%) and DC (100%), but a decrease in the dynamics for the TC (69%). Conclusion: a non-invasive method for the assessment of bowel motility was developed for the first time. The use of functional cine MRI utilizing a prokinetic stimulus allowed visualisation and quantification of large bowel motility

  3. Gastric motility measurement and evaluation of functional dyspepsia by a bio-impedance method

    International Nuclear Information System (INIS)

    Li, Zhangyong; Ren, Chaoshi

    2008-01-01

    In order to investigate the complex course of the electrical and mechanical processes of functional dyspepsia (FD), it is necessary to extract gastric motility information on both electricity and mechanism. According to the clinical standardization, 36 volunteers with functional dyspepsia were selected. The signal processing device has been designed by Chongqing University of Posts and Telecommunications. Multi-resolution analysis (MRA) decomposed the two signals of impedance gastric motility (IGM) and electrogastrogram (EGG) collected from the body surface. The wavelet transform is addressed to separate the IGM and EGG signals from impedance signals due to breathing and blood flow. By means of the energy and frequency spectrum analysis technique, the signals can be classified according to the dominant power and dominant frequency. Some indices, such as frequencies of EGG and IGM, signal power spectrum and dynamic spectrum, the rates of rhythm and power for the normal EGG and IGM and so on, can also be calculated. The primary experiments of gastric motility measurement and evaluation are executed by including healthy humans (control group: CG) and patients with FD (pathologic group: PG). There are significant differences in the temporal-domain and frequency-domain properties between the two groups. The main frequency of the CG belongs to 2–4 CPM and is clear and very regular, while the main frequency of the PG is much disordered. The peak of the maximal power of the CG belongs to 2–4 CPM and 1–2 CPM for the PG. The percentage of normal frequency (PNF) for the CG is 0.704 ± 0.255 and 0.402 ± 1.145 for the PG. The frequency instability coefficient (FIC) for the CG is 0.182 ± 0.059 and 0.374 ± 0.086 for the PG. The percentage of normal power (PNP) for the CG is 0.592 ± 0.044 and 0.468 ± 0.142 for the PG. The power instability coefficient (PIC) for the CG is 1.576 ± 0.481 and 4.006 ± 0.711 for the PG. The results of the experiments show that the proposed

  4. Lysophosphatidic acid signaling via LPA_1 and LPA_3 regulates cellular functions during tumor progression in pancreatic cancer cells

    International Nuclear Information System (INIS)

    Fukushima, Kaori; Takahashi, Kaede; Yamasaki, Eri; Onishi, Yuka; Fukushima, Nobuyuki; Honoki, Kanya; Tsujiuchi, Toshifumi

    2017-01-01

    Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors exhibits a variety of biological effects, such as cell proliferation, motility and differentiation. The aim of this study was to evaluate the roles of LPA_1 and LPA_3 in cellular functions during tumor progression in pancreatic cancer cells. LPA_1 and LPA_3 knockdown cells were generated from PANC-1 cells. The cell motile and invasive activities of PANC-1 cells were inhibited by LPA_1 and LPA_3 knockdown. In gelatin zymography, LPA_1 and LPA_3 knockdown cells indicated the low activation of matrix metalloproteinase-2 (MMP-2) in the presence of LPA. Next, to assess whether LPA_1 and LPA_3 regulate cellular functions induced by anticancer drug, PANC-1 cells were treated with cisplatin (CDDP) for approximately 6 months. The cell motile and invasive activities of long-term CDDP treated cells were markedly higher than those of PANC-1 cells, correlating with the expression levels of LPAR1 and LPAR3 genes. In soft agar assay, the long-term CDDP treated cells formed markedly large sized colonies. In addition, the cell motile and invasive activities enhanced by CDDP were significantly suppressed by LPA_1 and LPA_3 knockdown as well as colony formation. These results suggest that LPA signaling via LPA_1 and LPA_3 play an important role in the regulation of cellular functions during tumor progression in PANC-1 cells. - Highlights: • The cell motile and invasive activities of PANC-1 cells were stimulated by LPA_1 and LPA_3. • LPA_1 and LPA_3 enhanced MMP-2 activation in PANC-1 cells. • The expressions of LPAR1 and LPAR3 genes were elevated in PANC-1 cells treated with cisplatin. • The cell motile and invasive activities of PANC-1 cells treated with cisplatin were suppressed by LPA_1 and LPA_3 knockdown. • LPA_1 and LPA_3 are involved in the regulation of cellular functions during tumor progression in PANC-1 cells.

  5. AMP-activated kinase in human spermatozoa: identification, intracellular localization, and key function in the regulation of sperm motility

    Directory of Open Access Journals (Sweden)

    Violeta Calle-Guisado

    2017-01-01

    Full Text Available AMP-activated kinase (AMPK, a protein that regulates energy balance and metabolism, has recently been identified in boar spermatozoa where regulates key functional sperm processes essential for fertilization. This work′s aims are AMPK identification, intracellular localization, and their role in human spermatozoa function. Semen was obtained from healthy human donors. Sperm AMPK and phospho-Thr172-AMPK were analyzed by Western blotting and indirect immunofluorescence. High- and low-quality sperm populations were separated by a 40%-80% density gradient. Human spermatozoa motility was evaluated by an Integrated Semen Analysis System (ISAS in the presence or absence of the AMPK inhibitor compound C (CC. AMPK is localized along the human spermatozoa, at the entire acrosome, midpiece and tail with variable intensity, whereas its active form, phospho-Thr172-AMPK, shows a prominent staining at the acrosome and sperm tail with a weaker staining in the midpiece and the postacrosomal region. Interestingly, spermatozoa bearing an excess residual cytoplasm show strong AMPK staining in this subcellular compartment. Both AMPK and phospho-Thr172-AMPK human spermatozoa contents exhibit important individual variations. Moreover, active AMPK is predominant in the high motility sperm population, where shows a stronger intensity compared with the low motility sperm population. Inhibition of AMPK activity in human spermatozoa by CC treatment leads to a significant reduction in any sperm motility parameter analyzed: percent of motile sperm, sperm velocities, progressivity, and other motility coefficients. This work identifies and points out AMPK as a new molecular mechanism involved in human spermatozoa motility. Further AMPK implications in the clinical efficiency of assisted reproduction and in other reproductive areas need to be studied.

  6. AMP-activated kinase in human spermatozoa: identification, intracellular localization, and key function in the regulation of sperm motility

    Science.gov (United States)

    Calle-Guisado, Violeta; de Llera, Ana Hurtado; Martin-Hidalgo, David; Mijares, Jose; Gil, Maria C; Alvarez, Ignacio S; Bragado, Maria J; Garcia-Marin, Luis J

    2017-01-01

    AMP-activated kinase (AMPK), a protein that regulates energy balance and metabolism, has recently been identified in boar spermatozoa where regulates key functional sperm processes essential for fertilization. This work's aims are AMPK identification, intracellular localization, and their role in human spermatozoa function. Semen was obtained from healthy human donors. Sperm AMPK and phospho-Thr172-AMPK were analyzed by Western blotting and indirect immunofluorescence. High- and low-quality sperm populations were separated by a 40%–80% density gradient. Human spermatozoa motility was evaluated by an Integrated Semen Analysis System (ISAS) in the presence or absence of the AMPK inhibitor compound C (CC). AMPK is localized along the human spermatozoa, at the entire acrosome, midpiece and tail with variable intensity, whereas its active form, phospho-Thr172-AMPK, shows a prominent staining at the acrosome and sperm tail with a weaker staining in the midpiece and the postacrosomal region. Interestingly, spermatozoa bearing an excess residual cytoplasm show strong AMPK staining in this subcellular compartment. Both AMPK and phospho-Thr172-AMPK human spermatozoa contents exhibit important individual variations. Moreover, active AMPK is predominant in the high motility sperm population, where shows a stronger intensity compared with the low motility sperm population. Inhibition of AMPK activity in human spermatozoa by CC treatment leads to a significant reduction in any sperm motility parameter analyzed: percent of motile sperm, sperm velocities, progressivity, and other motility coefficients. This work identifies and points out AMPK as a new molecular mechanism involved in human spermatozoa motility. Further AMPK implications in the clinical efficiency of assisted reproduction and in other reproductive areas need to be studied. PMID:27678462

  7. Keeping the LINC: the importance of nucleocytoskeletal coupling in intracellular force transmission and cellular function.

    Science.gov (United States)

    Lombardi, Maria L; Lammerding, Jan

    2011-12-01

    Providing a stable physical connection between the nucleus and the cytoskeleton is essential for a wide range of cellular functions and it could also participate in mechanosensing by transmitting intra- and extra-cellular mechanical stimuli via the cytoskeleton to the nucleus. Nesprins and SUN proteins, located at the nuclear envelope, form the LINC (linker of nucleoskeleton and cytoskeleton) complex that connects the nucleus to the cytoskeleton; underlying nuclear lamins contribute to anchoring LINC complex components at the nuclear envelope. Disruption of the LINC complex or loss of lamins can result in disturbed perinuclear actin and intermediate filament networks and causes severe functional defects, including impaired nuclear positioning, cell polarization and cell motility. Recent studies have identified the LINC complex as the major force-transmitting element at the nuclear envelope and suggest that many of the aforementioned defects can be attributed to disturbed force transmission between the nucleus and the cytoskeleton. Thus mutations in nesprins, SUN proteins or lamins, which have been linked to muscular dystrophies and cardiomyopathies, may weaken or completely eliminate LINC complex function at the nuclear envelope and result in impaired intracellular force transmission, thereby disrupting critical cellular functions.

  8. Involvement of FFA1 and FFA4 in the regulation of cellular functions during tumor progression in colon cancer cells.

    Science.gov (United States)

    Takahashi, Kaede; Fukushima, Kaori; Onishi, Yuka; Minami, Kanako; Otagaki, Shiho; Ishimoto, Kaichi; Fukushima, Nobuyuki; Honoki, Kanya; Tsujiuchi, Toshifumi

    2018-08-01

    Free fatty acid receptor 1 (FFA1) and FFA4 mediate a variety of biological responses through binding of medium- and long-chain free fatty acids. The aim of this study was to investigate an involvement of FFA1 and FFA4 in the regulation of cellular functions during tumor progression in colon cancer cells. The long-term fluorouracil (5-FU) and cisplatin (CDDP) treated cells were generated from DLD1 cells (DLD-5FU and DLD-CDDP cells, respectively). FFAR1 expressions were lower in DLD-5FU and DLD-CDDP cells than in DLD1 cells. In contrast, DLD-5FU and DLD-CDDP cells showed the high FFAR4 expressions, compared with DLD1 cells. The cell motile activities of DLD-5FU and DLD-CDDP cells were reduced by GW9508 which is an agonist of FFA1 and FFA4. Moreover, GW1100, an antagonist of FFA1, inhibited the cell motile activities of DLD-5FU and DLD-CDDP cells. To evaluate whether FFA1 and FFA4 regulate the enhancement of cell motility, invasion and colony formation, highly migratory (hmDLD1) cells were established from DLD1 cells. FFAR1 expression was significantly higher in hmDLD1 cells than in DLD1 cells, but no change of FFAR4 expression was observed. The elevated cell motile and invasive activities and colony formation of hmDLD1 cells were suppressed by FFA1 inhibition. These results suggest that FFA1 and FFA4 are involved in the regulation of cellular functions during tumor progression in colon cancer DLD1 cells. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Cellular regulation of the structure and function of aortic valves

    Directory of Open Access Journals (Sweden)

    Ismail El-Hamamsy

    2010-01-01

    Full Text Available The aortic valve was long considered a passive structure that opens and closes in response to changes in transvalvular pressure. Recent evidence suggests that the aortic valve performs highly sophisticated functions as a result of its unique microscopic structure. These functions allow it to adapt to its hemodynamic and mechanical environment. Understanding the cellular and molecular mechanisms involved in normal valve physiology is essential to elucidate the mechanisms behind valve disease. We here review the structure and developmental biology of aortic valves; we examine the role of its cellular parts in regulating its function and describe potential pathophysiological and clinical implications.

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

    Directory of Open Access Journals (Sweden)

    Chou-Kit Chou

    2015-07-01

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

  11. NCAM regulates cell motility

    DEFF Research Database (Denmark)

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

    2002-01-01

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

  12. Nanoparticle Surface Functionality Dictates Cellular and Systemic Toxicity

    DEFF Research Database (Denmark)

    Saei, Amir Ata; Yazdani, Mahdieh; Lohse, Samuel E.

    2017-01-01

    can greatly enhance subsequent therapeutic effects of NPs while diminishing their adverse side effects. In this review, we will focus on the effect of surface functionality on the cellular uptake and the transport of NPs by various subcellular processes.......Engineered nanoparticles (NPs) have opened new frontiers in therapeutics and diagnostics in recent years. The surface functionality of these nanoparticles often predominates their interactions with various biological components of human body, and proper selection or control of surface functionality...

  13. New structural and functional defects in polyphosphate deficient bacteria: A cellular and proteomic study

    Directory of Open Access Journals (Sweden)

    Chávez Francisco P

    2010-01-01

    Full Text Available Abstract Background Inorganic polyphosphate (polyP, a polymer of tens or hundreds of phosphate residues linked by ATP-like bonds, is found in all organisms and performs a wide variety of functions. PolyP is synthesized in bacterial cells by the actions of polyphosphate kinases (PPK1 and PPK2 and degraded by exopolyphosphatase (PPX. Bacterial cells with polyP deficiencies due to knocking out the ppk1 gene are affected in many structural and important cellular functions such as motility, quorum sensing, biofilm formation and virulence among others. The cause of this pleiotropy is not entirely understood. Results The overexpression of exopolyphosphatase in bacteria mimicked some pleitropic defects found in ppk1 mutants. By using this approach we found new structural and functional defects in the polyP-accumulating bacteria Pseudomonas sp. B4, which are most likely due to differences in the polyP-removal strategy. Colony morphology phenotype, lipopolysaccharide (LPS structure changes and cellular division malfunction were observed. Finally, we used comparative proteomics in order to elucidate the cellular adjustments that occurred during polyP deficiency in this bacterium and found some clues that helped to understand the structural and functional defects observed. Conclusions The results obtained suggest that during polyP deficiency energy metabolism and particularly nucleoside triphosphate (NTP formation were affected and that bacterial cells overcame this problem by increasing the flux of energy-generating metabolic pathways such as tricarboxilic acid (TCA cycle, β-oxidation and oxidative phosphorylation and by reducing energy-consuming ones such as active transporters and amino acid biosynthesis. Furthermore, our results suggest that a general stress response also took place in the cell during polyP deficiency.

  14. The CORVET complex: compositions, function, and impact on cellular behaviour

    NARCIS (Netherlands)

    Jonker, CTH

    2016-01-01

    The endolysosomal system is positioned on the crossroad of the intracellular and extracellular environment and is therefore crucial to regulate many cellular processes. Proper function of the endolysosomal system greatly depends on the concept of membrane identity; the controlled protein and lipid

  15. Esophageal motility disorders

    International Nuclear Information System (INIS)

    Hannig, C.; Rummeny, E.; Wuttge-Hannig, A.

    2007-01-01

    For the better understanding of esophageal motility, the muscle texture and the distribution of skeletal and smooth muscle fibers in the esophagus are of crucial importance. Esophageal physiology will be shortly mentioned as far as necessary for a comprehensive understanding of peristaltic disturbances. Besides the pure depiction of morphologic criteria, a complete esophageal study has to include an analysis of the motility. New diagnostic tools with reduced radiation for dynamic imaging (digital fluoroscopy, videofluoroscopy) at 4-30 frames/s are available. Radiomanometry is a combination of a functional pressure measurement and a simultaneous dynamic morphologic analysis. Esophageal motility disorders are subdivided by radiologic and manometric criteria into primary, secondary, and nonclassifiable forms. Primary motility disorders of the esophagus are achalasia, diffuse esophageal spasm, nutcracker esophagus, and the hypertonic lower esophageal sphincter. The secondary motility disorders include pseudoachalasia, reflux-associated motility disorders, functionally caused impactions, Boerhaave's syndrome, Chagas' disease, scleroderma, and presbyesophagus. The nonclassificable motility disorders (NEMD) are a very heterogeneous collective. (orig.) [de

  16. Computer Modeling of the Earliest Cellular Structures and Functions

    Science.gov (United States)

    Pohorille, Andrew; Chipot, Christophe; Schweighofer, Karl

    2000-01-01

    In the absence of extinct or extant record of protocells (the earliest ancestors of contemporary cells). the most direct way to test our understanding of the origin of cellular life is to construct laboratory models of protocells. Such efforts are currently underway in the NASA Astrobiology Program. They are accompanied by computational studies aimed at explaining self-organization of simple molecules into ordered structures and developing designs for molecules that perform proto-cellular functions. Many of these functions, such as import of nutrients, capture and storage of energy. and response to changes in the environment are carried out by proteins bound to membranestructures at water-membrane interfaces and insert into membranes, (b) how these peptides aggregate to form membrane-spanning structures (eg. channels), and (c) by what mechanisms such aggregates perform essential proto-cellular functions, such as proton transport of protons across cell walls, a key step in cellular bioenergetics. The simulations were performed using the molecular dynamics method, in which Newton's equations of motion for each item in the system are solved iteratively. The problems of interest required simulations on multi-nanosecond time scales, which corresponded to 10(exp 6)-10(exp 8) time steps.

  17. New advances in gastrointestinal motility research

    CERN Document Server

    Pullan, A; Farrugia, G

    2013-01-01

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

  18. Presence and function of dopamine transporter (DAT in stallion sperm: dopamine modulates sperm motility and acrosomal integrity.

    Directory of Open Access Journals (Sweden)

    Javier A Urra

    Full Text Available Dopamine is a catecholamine with multiple physiological functions, playing a key role in nervous system; however its participation in reproductive processes and sperm physiology is controversial. High dopamine concentrations have been reported in different portions of the feminine and masculine reproductive tract, although the role fulfilled by this catecholamine in reproductive physiology is as yet unknown. We have previously shown that dopamine type 2 receptor is functional in boar sperm, suggesting that dopamine acts as a physiological modulator of sperm viability, capacitation and motility. In the present study, using immunodetection methods, we revealed the presence of several proteins important for the dopamine uptake and signalling in mammalian sperm, specifically monoamine transporters as dopamine (DAT, serotonin (SERT and norepinephrine (NET transporters in equine sperm. We also demonstrated for the first time in equine sperm a functional dopamine transporter using 4-[4-(Dimethylaminostyryl]-N-methylpyridinium iodide (ASP(+, as substrate. In addition, we also showed that dopamine (1 mM treatment in vitro, does not affect sperm viability but decreases total and progressive sperm motility. This effect is reversed by blocking the dopamine transporter with the selective inhibitor vanoxerine (GBR12909 and non-selective inhibitors of dopamine reuptake such as nomifensine and bupropion. The effect of dopamine in sperm physiology was evaluated and we demonstrated that acrosome integrity and thyrosine phosphorylation in equine sperm is significantly reduced at high concentrations of this catecholamine. In summary, our results revealed the presence of monoamine transporter DAT, NET and SERT in equine sperm, and that the dopamine uptake by DAT can regulate sperm function, specifically acrosomal integrity and sperm motility.

  19. Lysophosphatidic acid signaling via LPA{sub 1} and LPA{sub 3} regulates cellular functions during tumor progression in pancreatic cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kaori; Takahashi, Kaede; Yamasaki, Eri; Onishi, Yuka [Division of Molecular Oncology, Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Honoki, Kanya [Department of Orthopedic Surgery, Nara Medical University, 840 Shijo-cho, Kashihara, Nara 634-8521 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Molecular Oncology, Department of Life Science, Faculty of Science and Engineering, Kindai University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

    2017-03-01

    Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors exhibits a variety of biological effects, such as cell proliferation, motility and differentiation. The aim of this study was to evaluate the roles of LPA{sub 1} and LPA{sub 3} in cellular functions during tumor progression in pancreatic cancer cells. LPA{sub 1} and LPA{sub 3} knockdown cells were generated from PANC-1 cells. The cell motile and invasive activities of PANC-1 cells were inhibited by LPA{sub 1} and LPA{sub 3} knockdown. In gelatin zymography, LPA{sub 1} and LPA{sub 3} knockdown cells indicated the low activation of matrix metalloproteinase-2 (MMP-2) in the presence of LPA. Next, to assess whether LPA{sub 1} and LPA{sub 3} regulate cellular functions induced by anticancer drug, PANC-1 cells were treated with cisplatin (CDDP) for approximately 6 months. The cell motile and invasive activities of long-term CDDP treated cells were markedly higher than those of PANC-1 cells, correlating with the expression levels of LPAR1 and LPAR3 genes. In soft agar assay, the long-term CDDP treated cells formed markedly large sized colonies. In addition, the cell motile and invasive activities enhanced by CDDP were significantly suppressed by LPA{sub 1} and LPA{sub 3} knockdown as well as colony formation. These results suggest that LPA signaling via LPA{sub 1} and LPA{sub 3} play an important role in the regulation of cellular functions during tumor progression in PANC-1 cells. - Highlights: • The cell motile and invasive activities of PANC-1 cells were stimulated by LPA{sub 1} and LPA{sub 3}. • LPA{sub 1} and LPA{sub 3} enhanced MMP-2 activation in PANC-1 cells. • The expressions of LPAR1 and LPAR3 genes were elevated in PANC-1 cells treated with cisplatin. • The cell motile and invasive activities of PANC-1 cells treated with cisplatin were suppressed by LPA{sub 1} and LPA{sub 3} knockdown. • LPA{sub 1} and LPA{sub 3} are involved in the regulation of cellular functions during tumor

  20. A Cellular Perspective on Brain Energy Metabolism and Functional Imaging

    KAUST Repository

    Magistretti, Pierre J.

    2015-05-01

    The energy demands of the brain are high: they account for at least 20% of the body\\'s energy consumption. Evolutionary studies indicate that the emergence of higher cognitive functions in humans is associated with an increased glucose utilization and expression of energy metabolism genes. Functional brain imaging techniques such as fMRI and PET, which are widely used in human neuroscience studies, detect signals that monitor energy delivery and use in register with neuronal activity. Recent technological advances in metabolic studies with cellular resolution have afforded decisive insights into the understanding of the cellular and molecular bases of the coupling between neuronal activity and energy metabolism and pointat a key role of neuron-astrocyte metabolic interactions. This article reviews some of the most salient features emerging from recent studies and aims at providing an integration of brain energy metabolism across resolution scales. © 2015 Elsevier Inc.

  1. Contribution of cellular autolysis to tissular functions during plant development

    OpenAIRE

    Escamez, Sacha; Tuominen, Hannele

    2017-01-01

    Plant development requires specific cells to be eliminated in a predictable and genetically regulated manner referred to as programmed cell death (PCD). However, the target cells do not merely die but they also undergo autolysis to degrade their cellular corpses. Recent progress in understanding developmental cell elimination suggests that distinct proteins execute PCD sensu stricto and autolysis. In addition, cell death alone and cell dismantlement can fulfill different functions. Hence, it ...

  2. A function for filamentous alpha-smooth muscle actin: Retardation of motility in human breast fibroblasts

    DEFF Research Database (Denmark)

    Rønnov-Jessen, Lone; Petersen, Ole William

    1996-01-01

    .8 and 3.0 microns/h, respectively. To knock out the alpha-sm actin protein, several antisense phosphorothioate oligodeoxynucleotide (ODNs) were tested. One of these, 3'UTI, which is complementary to a highly evolutionary conserved 3' untranslated (3'UT) sequence of alpha-sm actin mRNA, was found to block...... alpha-sm actin synthesis completely without affecting the synthesis of any other proteins as analyzed by two-dimensional gel electrophoresis. Targeting by antisense 3'UTI significantly increased motility compared with the corresponding sense ODN. alpha-Sm actin inhibition also led to the formation...

  3. Cell Motility

    CERN Document Server

    Lenz, Peter

    2008-01-01

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

  4. Contribution of cellular autolysis to tissular functions during plant development.

    Science.gov (United States)

    Escamez, Sacha; Tuominen, Hannele

    2017-02-01

    Plant development requires specific cells to be eliminated in a predictable and genetically regulated manner referred to as programmed cell death (PCD). However, the target cells do not merely die but they also undergo autolysis to degrade their cellular corpses. Recent progress in understanding developmental cell elimination suggests that distinct proteins execute PCD sensu stricto and autolysis. In addition, cell death alone and cell dismantlement can fulfill different functions. Hence, it appears biologically meaningful to distinguish between the modules of PCD and autolysis during plant development. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  5. Electrostatic bio-manipulation for the modification of cellular functions

    International Nuclear Information System (INIS)

    Washizu, Masao

    2013-01-01

    The use of electrostatic field effects, including field-induced reversible-breakdown of the membrane and dielectrophoresis (DEP), in microfabricated structures are investigated. With the use of field constriction created by a micro-orifice whose diameter is smaller than the cells, controlled magnitude of pulsed voltage can be applied across the cell membrane regardless of the cell size, shape or orientation. As a result, the breakdown occurs reproducibly and with minimal invasiveness. The breakdown is used for two purposes, electroporation by which foreign substances can be fed into cells, and electrofusion which creates genetic and/or cytoplasmic mixture among two cells. When GFP plasmid is fed into MSC cell, the gene expression started within 2 hours, and finally observed in more than 50% of cells. For cell fusion, several ten percent fusion yield is achieved for most cell types, with the colony formation in several percents. Timing-controlled feeding foreign substances or mixing cellular contents, with high-yield and low-invasiveness, is expected to bring about a new technology for both genetic and epigenetic modifications of cellular functions, in such field as regenerative medicine.

  6. Rejuvenating cellular respiration for optimizing respiratory function: targeting mitochondria.

    Science.gov (United States)

    Agrawal, Anurag; Mabalirajan, Ulaganathan

    2016-01-15

    Altered bioenergetics with increased mitochondrial reactive oxygen species production and degradation of epithelial function are key aspects of pathogenesis in asthma and chronic obstructive pulmonary disease (COPD). This motif is not unique to obstructive airway disease, reported in related airway diseases such as bronchopulmonary dysplasia and parenchymal diseases such as pulmonary fibrosis. Similarly, mitochondrial dysfunction in vascular endothelium or skeletal muscles contributes to the development of pulmonary hypertension and systemic manifestations of lung disease. In experimental models of COPD or asthma, the use of mitochondria-targeted antioxidants, such as MitoQ, has substantially improved mitochondrial health and restored respiratory function. Modulation of noncoding RNA or protein regulators of mitochondrial biogenesis, dynamics, or degradation has been found to be effective in models of fibrosis, emphysema, asthma, and pulmonary hypertension. Transfer of healthy mitochondria to epithelial cells has been associated with remarkable therapeutic efficacy in models of acute lung injury and asthma. Together, these form a 3R model--repair, reprogramming, and replacement--for mitochondria-targeted therapies in lung disease. This review highlights the key role of mitochondrial function in lung health and disease, with a focus on asthma and COPD, and provides an overview of mitochondria-targeted strategies for rejuvenating cellular respiration and optimizing respiratory function in lung diseases. Copyright © 2016 the American Physiological Society.

  7. Stably Expressed Genes Involved in Basic Cellular Functions.

    Directory of Open Access Journals (Sweden)

    Kejian Wang

    Full Text Available Stably Expressed Genes (SEGs whose expression varies within a narrow range may be involved in core cellular processes necessary for basic functions. To identify such genes, we re-analyzed existing RNA-Seq gene expression profiles across 11 organs at 4 developmental stages (from immature to old age in both sexes of F344 rats (n = 4/group; 320 samples. Expression changes (calculated as the maximum expression / minimum expression for each gene of >19000 genes across organs, ages, and sexes ranged from 2.35 to >109-fold, with a median of 165-fold. The expression of 278 SEGs was found to vary ≤4-fold and these genes were significantly involved in protein catabolism (proteasome and ubiquitination, RNA transport, protein processing, and the spliceosome. Such stability of expression was further validated in human samples where the expression variability of the homologous human SEGs was significantly lower than that of other genes in the human genome. It was also found that the homologous human SEGs were generally less subject to non-synonymous mutation than other genes, as would be expected of stably expressed genes. We also found that knockout of SEG homologs in mouse models was more likely to cause complete preweaning lethality than non-SEG homologs, corroborating the fundamental roles played by SEGs in biological development. Such stably expressed genes and pathways across life-stages suggest that tight control of these processes is important in basic cellular functions and that perturbation by endogenous (e.g., genetics or exogenous agents (e.g., drugs, environmental factors may cause serious adverse effects.

  8. Investigation of gastric motility in patients with the overlap syndrome of the gastroesophageal reflux disease and functional dyspepsia

    Directory of Open Access Journals (Sweden)

    V. D. Pasechnikov

    2017-01-01

    Full Text Available Rationale:  The phenomenon of overlap  of two disorders, non-erosive gastroesophageal reflux disease (NERD and functional dyspepsia (FD is an important clinical problem,  while the  symptoms in such  patients  are  more  severe  and  prevalent than  in those  with non-overlapping NERD or FD. This phenomenon may lead to treatment failure, if therapy  does not take into account  the specific pathophysiological mechanisms  of the NERD and FD overlap.Aim: To study motility of the proximal and  distal parts  of the  stomach  in patients  with the overlap syndrome of NERD with FD.Materials and  methods:  The  study  enrolled  56  patients (34 women and 22 men, aged from 18 to 45 years, who met the diagnostic  criteria for NERD and FD (the Rome criteria III, esophageal endoscopy, 24-hour  pH  measurement  or  24-hour  impedance pH measurement, and  had  both  NERD  and  FD symptoms  simultaneously  (overlap; 46 healthy volunteers. The accommodation of the  proximal (fundal part  of the  stomach  and  motility of the distal gastric part  was assessed  by ultrasonography (Aixplorer, SuperSonic Imagine, France, with convex probe  1–6 MHz before  and  after the  intake of the liquid test food. The patients  filled in questionnaires to assess the symptoms  and their severity (scored from 0 to 3. The difference  between their mean ± standard  deviation (SD values was assessed  by Students  t-test  and  was considered  significant at p < 0.05.Results: After intake of the  liquid test  food, the  patients  with the  FD and NERD overlap syndrome demonstrated an advanced and statistically significant gastric motility abnormality  both  in its proximal and distal parts, compared to healthy control: accommodation disturbances and its reduction, decreased amplitude  (61.4 ± 7.5 vs 90.2 ± 6.9%, p < 0.05, frequency of contractions of the antrum during 3-minute interval (4.3 ± 1.5 vs 9.7 ± 1

  9. Functional characterization of a mouse testicular olfactory receptor and its role in chemosensing and in regulation of sperm motility.

    Science.gov (United States)

    Fukuda, Nanaho; Yomogida, Kentaro; Okabe, Masaru; Touhara, Kazushige

    2004-11-15

    Although a subset of the olfactory receptor (OR) gene family is expressed in testis, neither their developmental profile nor their physiological functions have been fully characterized. Here, we show that MOR23 (a mouse OR expressed in the olfactory epithelium and testis) functions as a chemosensing receptor in mouse germ cells. In situ hybridization showed that MOR23 was expressed in round spermatids during stages VI-VIII of spermatogenesis. Lyral, a cognate ligand of MOR23, caused an increase in intracellular Ca2+ in a fraction of spermatogenic cells and spermatozoa. We also generated transgenic mice that express high levels of MOR23 in the testis and examined the response of their germ cells to lyral. The results provided evidence that lyral-induced Ca2+ increases were indeed mediated by MOR23. In a sperm accumulation assay, spermatozoa migrated towards an increasing gradient of lyral. Tracking and sperm flagellar analyses suggest that Ca2+ increases caused by MOR23 activation lead to modulation of flagellar configuration, resulting in chemotaxis. By contrast, a gradient of a cAMP analog or K8.6 solution, which elicit Ca2+ influx in spermatozoa, did not cause sperm accumulation, indicating that chemosensing and regulation of sperm motility was due to an OR-mediated local Ca2+ increase. The present studies indicate that mouse testicular ORs might play a role in chemoreception during sperm-egg communication and thereby regulate fertilization.

  10. Comparison of cryopreserved human sperm in vapor and liquid phases of liquid nitrogen: effect on motility parameters, morphology, and sperm function.

    Science.gov (United States)

    Punyatanasakchai, Piyaphan; Sophonsritsuk, Areephan; Weerakiet, Sawaek; Wansumrit, Surapee; Chompurat, Deonthip

    2008-11-01

    To compare the effects of cryopreserved sperm in vapor and liquid phases of liquid nitrogen on sperm motility, morphology, and sperm function. Experimental study. Andrology laboratory at Ramathibodi Hospital, Thailand. Thirty-eight semen samples with normal motility and sperm count were collected from 38 men who were either patients of an infertility clinic or had donated sperm for research. Each semen sample was divided into two aliquots. Samples were frozen with static-phase vapor cooling. One aliquot was plunged into liquid nitrogen (-196 degrees C), and the other was stored in vapor-phase nitrogen (-179 degrees C) for 3 days. Thawing was performed at room temperature. Motility was determined by using computer-assisted semen analysis, sperm morphology was determined by using eosin-methylene blue staining, and sperm function was determined by using a hemizona binding test. Most of the motility parameters of sperm stored in the vapor phase were not significantly different from those stored in the liquid phase of liquid nitrogen, except in amplitude of lateral head displacement. The percentages of normal sperm morphology in both vapor and liquid phases also were not significantly different. There was no significant difference in the number of bound sperm in hemizona between sperm cryopreserved in both vapor and liquid phases of liquid nitrogen. Cryopreservation of human sperm in a vapor phase of liquid nitrogen was comparable to cryopreservation in a liquid phase of liquid nitrogen.

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

    KAUST Repository

    Guerrero, Pilar

    2015-04-02

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

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

    KAUST Repository

    Guerrero, Pilar; Byrne, Helen M.; Maini, Philip K.; Alarcó n, Tomá s

    2015-01-01

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

  13. Insights into the physiological function of cellular prion protein

    Directory of Open Access Journals (Sweden)

    Martins V.R.

    2001-01-01

    Full Text Available Prions have been extensively studied since they represent a new class of infectious agents in which a protein, PrPsc (prion scrapie, appears to be the sole component of the infectious particle. They are responsible for transmissible spongiform encephalopathies, which affect both humans and animals. The mechanism of disease propagation is well understood and involves the interaction of PrPsc with its cellular isoform (PrPc and subsequently abnormal structural conversion of the latter. PrPc is a glycoprotein anchored on the cell surface by a glycosylphosphatidylinositol moiety and expressed in most cell types but mainly in neurons. Prion diseases have been associated with the accumulation of the abnormally folded protein and its neurotoxic effects; however, it is not known if PrPc loss of function is an important component. New efforts are addressing this question and trying to characterize the physiological function of PrPc. At least four different mouse strains in which the PrP gene was ablated were generated and the results regarding their phenotype are controversial. Localization of PrPc on the cell membrane makes it a potential candidate for a ligand uptake, cell adhesion and recognition molecule or a membrane signaling molecule. Recent data have shown a potential role for PrPc in the metabolism of copper and moreover that this metal stimulates PrPc endocytosis. Our group has recently demonstrated that PrPc is a high affinity laminin ligand and that this interaction mediates neuronal cell adhesion and neurite extension and maintenance. Moreover, PrPc-caveolin-1 dependent coupling seems to trigger the tyrosine kinase Fyn activation. These data provide the first evidence for PrPc involvement in signal transduction.

  14. Cellular function of neuropathy target esterase in lysophosphatidylcholine action

    International Nuclear Information System (INIS)

    Vose, Sarah C.; Fujioka, Kazutoshi; Gulevich, Alex G.; Lin, Amy Y.; Holland, Nina T.; Casida, John E.

    2008-01-01

    Neuropathy target esterase (NTE) plays critical roles in embryonic development and maintenance of peripheral axons. It is a secondary target of some organophosphorus toxicants including analogs of insecticides and chemical warfare agents. Although the mechanistic role of NTE in vivo is poorly defined, it is known to hydrolyze lysophosphatidylcholine (LPC) in vitro and may protect cell membranes from cytotoxic accumulation of LPC. To determine the cellular function of NTE, Neuro-2a and COS-7 cells were transfected with a full-length human NTE-containing plasmid yielding recombinant NTE (rNTE). We find the same inhibitor sensitivity and specificity profiles for rNTE assayed with LPC or phenyl valerate (a standard NTE substrate) and that this correlation extends to the LPC hydrolases of human brain, lymphocytes and erythrocytes. All of these LPC hydrolases are therefore very similar to each other in respect to a conserved inhibitor binding site conformation. NTE is expressed in brain and lymphocytes and contributes to LPC hydrolase activities in these tissues. The enzyme or enzymes responsible for erythrocyte LPC hydrolase activity remain to be identified. We also show that rNTE protects Neuro-2a and COS-7 cells from exogenous LPC cytotoxicity. Expression of rNTE in Neuro-2a cells alters their phospholipid balance (analyzed by liquid chromatography-mass spectrometry with single ion monitoring) by lowering LPC-16:0 and LPC-18:0 and elevating glycerophosphocholine without a change in phosphatidylcholine-16:0/18:1 or 16:0/18:2. NTE therefore serves an important function in LPC homeostasis and action

  15. The effects of itopride on oesophageal motility and lower oesophageal sphincter function in man.

    Science.gov (United States)

    Scarpellini, E; Vos, R; Blondeau, K; Boecxstaens, V; Farré, R; Gasbarrini, A; Tack, J

    2011-01-01

    Itopride is a new prokinetic agent that combines antidopaminergic and cholinesterase inhibitory actions. Previous studies suggested that itopride improves heartburn in functional dyspepsia, and decreases oesophageal acid exposure in gastro-oesophageal reflux disease. It remains unclear whether this effect is due to effects of itopride on the lower oesophageal sphincter (LES). To study the effects of itopride on fasting and postprandial LES function in healthy subjects. Twelve healthy volunteers (five men; 32.6 ± 2.0 years) underwent three oesophageal sleeve manometry studies after 3 days premedication with itopride 50 mg, itopride 100 mg or placebo t.d.s. Drug was administered after 30 min and a standardized meal was administered after 90 min, with measurements continuing to 120 min postprandially. Throughout the study, 10 wet swallows were administered at 30-min intervals, and gastrointestinal symptoms were scored on 100 mm visual analogue scales at 15-min intervals. Lower oesophageal sphincter resting pressures, swallow-induced relaxations and the amplitude or duration of peristaltic contractions were not altered by both doses of itopride, at all time points. Itopride pre-treatment inhibited the meal-induced rise of transient LES relaxations (TLESRs). Itopride inhibits TLESRs without significantly affecting oesophageal peristaltic function or LES pressure. These observations support further studies with itopride in gastro-oesophageal reflux disease. © 2010 Blackwell Publishing Ltd.

  16. Cellular Chaperones As Therapeutic Targets in ALS to Restore Protein Homeostasis and Improve Cellular Function

    Directory of Open Access Journals (Sweden)

    Bernadett Kalmar

    2017-09-01

    Full Text Available Heat shock proteins (Hsps are ubiquitously expressed chaperone proteins that enable cells to cope with environmental stresses that cause misfolding and denaturation of proteins. With aging this protein quality control machinery becomes less effective, reducing the ability of cells to cope with damaging environmental stresses and disease-causing mutations. In neurodegenerative disorders such as Amyotrophic Lateral Sclerosis (ALS, such mutations are known to result in protein misfolding, which in turn results in the formation of intracellular aggregates cellular dysfunction and eventual neuronal death. The exact cellular pathology of ALS and other neurodegenerative diseases has been elusive and thus, hindering the development of effective therapies. However, a common scheme has emerged across these “protein misfolding” disorders, in that the mechanism of disease involves one or more aspects of proteostasis; from DNA transcription, RNA translation, to protein folding, transport and degradation via proteosomal and autophagic pathways. Interestingly, members of the Hsp family are involved in each of these steps facilitating normal protein folding, regulating the rate of protein synthesis and degradation. In this short review we summarize the evidence that suggests that ALS is a disease of protein dyshomeostasis in which Hsps may play a key role. Overwhelming evidence now indicates that enabling protein homeostasis to cope with disease-causing mutations might be a successful therapeutic strategy in ALS, as well as other neurodegenerative diseases. Novel small molecule co-inducers of Hsps appear to be able to achieve this aim. Arimoclomol, a hydroxylamine derivative, has shown promising results in cellular and animal models of ALS, as well as other protein misfolding diseases such as Inclusion Body Myositis (IBM. Initial clinical investigations of Arimoclomol have shown promising results. Therefore, it is possible that the long series of

  17. An evolutionary link between capsular biogenesis and surface motility in bacteria.

    Science.gov (United States)

    Agrebi, Rym; Wartel, Morgane; Brochier-Armanet, Céline; Mignot, Tâm

    2015-05-01

    Studying the evolution of macromolecular assemblies is important to improve our understanding of how complex cellular structures evolved, and to identify the functional building blocks that are involved. Recent studies suggest that the macromolecular complexes that are involved in two distinct processes in Myxococcus xanthus - surface motility and sporulation - are derived from an ancestral polysaccharide capsule assembly system. In this Opinion article, we argue that the available data suggest that the motility machinery evolved from this capsule assembly system following a gene duplication event, a change in carbohydrate polymer specificity and the acquisition of additional proteins by the motility complex, all of which are key features that distinguish the motility and sporulation systems. Furthermore, the presence of intermediates of these systems in bacterial genomes suggests a testable evolutionary model for their emergence and spread.

  18. A Xanthomonas citri subsp citri hypothetical protein related to virulence contains a non-functional HD domain and is implicated in flagellar motility.

    Science.gov (United States)

    Vieira, F C F; Gonçalves, A M; Mendoza, E F R; Ferreira, R M; Costa, M L M; Balbuena, T S; Sebinelli, H G; Ciancaglini, P; Pizauro Junior, J M; Ferro, J A

    2017-08-31

    Citrus canker, caused by the Gram-negative bacterium Xanthomonas citri subsp citri (Xac), severely affects most economically important citrus varieties worldwide. A previous study showed that disruption of the ORF XAC1201 from the Xac 306 strain by transposon Tn5 decreased bacterium virulence in the Rangpur lime host (Citrus limonia L. Osbeck). However, little is known regarding the possible function of the hypothetical protein XAC1201 and how it affects the virulence of Xac 306. Here, we confirmed that disruption of ORF XAC1201 reduces Xac 306 virulence in two different hosts, delaying the onset of typical symptoms. In silico analysis suggested that XAC1201 interacts with the flagellar proteins FliM and FliL, known to be an important factor for virulence. In fact, motility assays revealed that the XAC1201 mutant has a significant difference in motility compared to the wild-type Xac 306. Also, a 3-D structure model revealed modified cofactor binding sites and suggested that XAC1201 has a non-functional HD domain. This hypothesis was confirmed by enzymatic assays performed in purified, XAC1201 recombinant protein expressed in Escherichia coli, which revealed no significant activities previously associated with HD domains for the tested substrates. Thus, the role of the XAC1201 protein in Xac 306 virulence seems to be related to flagellar motility, although a non-classic role for the HD domain cannot be dismissed.

  19. Mapping brain structure and function: cellular resolution, global perspective.

    Science.gov (United States)

    Zupanc, Günther K H

    2017-04-01

    A comprehensive understanding of the brain requires analysis, although from a global perspective, with cellular, and even subcellular, resolution. An important step towards this goal involves the establishment of three-dimensional high-resolution brain maps, incorporating brain-wide information about the cells and their connections, as well as the chemical architecture. The progress made in such anatomical brain mapping in recent years has been paralleled by the development of physiological techniques that enable investigators to generate global neural activity maps, also with cellular resolution, while simultaneously recording the organism's behavioral activity. Combination of the high-resolution anatomical and physiological maps, followed by theoretical systems analysis of the deduced network, will offer unprecedented opportunities for a better understanding of how the brain, as a whole, processes sensory information and generates behavior.

  20. Automated measurement of cell motility and proliferation

    Directory of Open Access Journals (Sweden)

    Goff Julie

    2005-04-01

    Full Text Available Abstract Background Time-lapse microscopic imaging provides a powerful approach for following changes in cell phenotype over time. Visible responses of whole cells can yield insight into functional changes that underlie physiological processes in health and disease. For example, features of cell motility accompany molecular changes that are central to the immune response, to carcinogenesis and metastasis, to wound healing and tissue regeneration, and to the myriad developmental processes that generate an organism. Previously reported image processing methods for motility analysis required custom viewing devices and manual interactions that may introduce bias, that slow throughput, and that constrain the scope of experiments in terms of the number of treatment variables, time period of observation, replication and statistical options. Here we describe a fully automated system in which images are acquired 24/7 from 384 well plates and are automatically processed to yield high-content motility and morphological data. Results We have applied this technology to study the effects of different extracellular matrix compounds on human osteoblast-like cell lines to explore functional changes that may underlie processes involved in bone formation and maintenance. We show dose-response and kinetic data for induction of increased motility by laminin and collagen type I without significant effects on growth rate. Differential motility response was evident within 4 hours of plating cells; long-term responses differed depending upon cell type and surface coating. Average velocities were increased approximately 0.1 um/min by ten-fold increases in laminin coating concentration in some cases. Comparison with manual tracking demonstrated the accuracy of the automated method and highlighted the comparative imprecision of human tracking for analysis of cell motility data. Quality statistics are reported that associate with stage noise, interference by non

  1. Sexual Experience in Female Rodents: Cellular Mechanisms and Functional Consequences

    Science.gov (United States)

    Meisel, Robert L.; Mullins, Amanda J.

    2007-01-01

    The neurobiology of female sexual behavior has largely focused on mechanisms of hormone action on nerve cells and how these effects translate into the display of copulatory motor patterns. Of equal importance, though less studied, are some of the consequences of engaging in sexual behavior, including the rewarding properties of sexual interactions and how sexual experience alters copulatory efficiency. This review summarizes the effects of sexual experience on reward processes and copulation in female Syrian hamsters. Neural correlates of these sexual interactions include long-term cellular changes in dopamine transmission and postsynaptic signaling pathways related to neuronal plasticity (e.g., dendritic spine formation). Taken together, these studies suggest that sexual experience enhances the reinforcing properties of sexual behavior, which has the coincident outcome of increasing copulatory efficiency in a way that can increase reproductive success. PMID:16978593

  2. Cellular MYCro economics: Balancing MYC function with MYC expression.

    Science.gov (United States)

    Levens, David

    2013-11-01

    The expression levels of the MYC oncoprotein have long been recognized to be associated with the outputs of major cellular processes including proliferation, cell growth, apoptosis, differentiation, and metabolism. Therefore, to understand how MYC operates, it is important to define quantitatively the relationship between MYC input and expression output for its targets as well as the higher-order relationships between the expression levels of subnetwork components and the flow of information and materials through those networks. Two different views of MYC are considered, first as a molecular microeconomic manager orchestrating specific positive and negative responses at individual promoters in collaboration with other transcription and chromatin components, and second, as a macroeconomic czar imposing an overarching rule onto all active genes. In either case, c-myc promoter output requires multiple inputs and exploits diverse mechanisms to tune expression to the appropriate levels relative to the thresholds of expression that separate health and disease.

  3. Scintigraphic evaluation of gastrointestinal motility disorders

    Energy Technology Data Exchange (ETDEWEB)

    Choe, Jae Gol [College of Medicine, Korea Univ., Seoul (Korea, Republic of)

    2001-02-01

    Current scintigraphic tests of gastrointestinal motor function provides relevant pathophysiologic information, but their clinical utility is controversial. Many scintigraphic methods are developed to investigate gastrointestinal motility from oral cavity to colon. These are esophageal transit scintigraphy, oropharyngeal transit study, gastric emptying test, small bowel transit time measurement, colon transit study and gastroesopahgeal reflux scintigraphy. Scintigraphy of gastrointestinal tract is the most physiologic and noninvasive method to evaluate gastrointestinal motility disorders. Stomach emptying test is regarded as a gold standard in motility study. Gastrointestinal transit scintigraphy also has a certain role in assessment of drug effect to GI motility and changes after theraphy of motility disorders. Scintigraphy provides noninvasive and quantitative assessment of physiological transit throughout the gastrointestinal tract, and it is extremely useful for diagnosing gastrointestinal motor dysfunction. This article reviews the current procedures, indications, significance and guidelines for gastrointestinal motility measurements by scintigraphy.

  4. Scintigraphic evaluation of gastrointestinal motility disorders

    International Nuclear Information System (INIS)

    Choe, Jae Gol

    2001-01-01

    Current scintigraphic tests of gastrointestinal motor function provides relevant pathophysiologic information, but their clinical utility is controversial. Many scintigraphic methods are developed to investigate gastrointestinal motility from oral cavity to colon. These are esophageal transit scintigraphy, oropharyngeal transit study, gastric emptying test, small bowel transit time measurement, colon transit study and gastroesopahgeal reflux scintigraphy. Scintigraphy of gastrointestinal tract is the most physiologic and noninvasive method to evaluate gastrointestinal motility disorders. Stomach emptying test is regarded as a gold standard in motility study. Gastrointestinal transit scintigraphy also has a certain role in assessment of drug effect to GI motility and changes after theraphy of motility disorders. Scintigraphy provides noninvasive and quantitative assessment of physiological transit throughout the gastrointestinal tract, and it is extremely useful for diagnosing gastrointestinal motor dysfunction. This article reviews the current procedures, indications, significance and guidelines for gastrointestinal motility measurements by scintigraphy

  5. Agonists for G-protein-coupled receptor 84 (GPR84) alter cellular morphology and motility but do not induce pro-inflammatory responses in microglia

    OpenAIRE

    Wei, Li; Tokizane, Kyohei; Konishi, Hiroyuki; Yu, Hua-Rong; Kiyama, Hiroshi

    2017-01-01

    Background Several G-protein-coupled receptors (GPCRs) have been shown to be important signaling mediators between neurons and glia. In our previous screening for identification of nerve injury-associated GPCRs, G-protein-coupled receptor 84 (GPR84) mRNA showed the highest up-regulation by microglia after nerve injury. GPR84 is a pro-inflammatory receptor of macrophages in a neuropathic pain mouse model, yet its function in resident microglia in the central nervous system is poorly understood...

  6. Amine functionalized nanodiamond promotes cellular adhesion, proliferation and neurite outgrowth

    International Nuclear Information System (INIS)

    Hopper, A P; Dugan, J M; Gill, A A; Haycock, J W; Claeyssens, F; Fox, O J L; May, P W

    2014-01-01

    In this study, we report the production of amine functionalized nanodiamond. The amine functionalized nanodiamond forms a conformal monolayer on a negatively charged surface produced via plasma polymerization of acrylic acid. Nanodiamond terminated surfaces were studied as substrates for neuronal cell culture. NG108-15 neuroblastoma-glyoma hybrid cells were successfully cultured upon amine functionalized nanodiamond coated surfaces for between 1 and 7 d. Additionally, primary dorsal root ganglion (DRG) neurons and Schwann cells isolated from Wistar rats were also successfully cultured over a period of 21 d illustrating the potential of the coating for applications in the treatment of peripheral nerve injury. (paper)

  7. The coiled-coil domain containing protein CCDC40 is essential for motile cilia function and left-right axis formation

    DEFF Research Database (Denmark)

    Becker-Heck, Anita; Zohn, Irene E; Okabe, Noriko

    2011-01-01

    Primary ciliary dyskinesia (PCD) is a genetically heterogeneous autosomal recessive disorder characterized by recurrent infections of the respiratory tract associated with the abnormal function of motile cilia. Approximately half of individuals with PCD also have alterations in the left-right...... organization of their internal organ positioning, including situs inversus and situs ambiguous (Kartagener's syndrome). Here, we identify an uncharacterized coiled-coil domain containing a protein, CCDC40, essential for correct left-right patterning in mouse, zebrafish and human. In mouse and zebrafish, Ccdc40...

  8. A Cellular Perspective on Brain Energy Metabolism and Functional Imaging

    KAUST Repository

    Magistretti, Pierre J.; Allaman, Igor

    2015-01-01

    The energy demands of the brain are high: they account for at least 20% of the body's energy consumption. Evolutionary studies indicate that the emergence of higher cognitive functions in humans is associated with an increased glucose utilization

  9. Three types of gall-bladder motility at men with chronic cholecystitis and pyelonephritis and accompanying their parameters of kidney excretory function as well as metabolism

    Directory of Open Access Journals (Sweden)

    Oksana M Ivanyts’ka

    2018-04-01

    Full Text Available Background. Previously it has been shown that balneotherapy in the spa Truskavets’ (Ukraїna in men with chronic cholecystitis combined with pyelonephritis causes changes in gall-bladder motility. This is combined with changes in diurese and urinary excretion of metabolites.Individual analysis revealed not only quantitative but also qualitative differences in the postprandial motility of the gall-bladder. The purpose of this study is to identify the parameters of kidney excretory function as well as metabolism under which three types of the gall-bladdermotility skills differ significantly from each other. Materialandmethods. The object of observationwere the same ones 22men aged24-70 years old,who cameto the spaTruskavets’ for the treatment of chronic cholecystitiscombined withpyelonephritis inremission. On thetone and motility of gall-bladder judged byits fasting and postprandial volume (echocamera “Radmir”. In the daily  determined content of oxalate and nitrogen metabolites: creatinine, urea and uric acid, electrolytes: phosphates, chloride, calcium, magnesium, potassium and sodium. Nitrogenous metabolites in plasma of venous blood were determined also. The survey was conducted twice, before and after balneotherapy. Results. The method of cluster analysis has formed three homogeneous cholekinetics groups, namely:normokinesia as well as hypertonic-hyperkinetic and hyperkinetic-hypertonic dyskinesia.The method of discriminatory analysis revealed 13 parameters of daily urine and three parameters of blood, as well as body weight and height, electrokinetic index and Kerdoe’s index, in the totality of which three types of cholekinetics are clearly delineated.Conclusion. The type of postprandial cholekinetics is naturally associated with a number of parameters of the excretory renal function and metabolism.

  10. Motility Disorders in Children.

    Science.gov (United States)

    Nurko, Samuel

    2017-06-01

    Gastrointestinal motility disorders in the pediatric population are common and can range from benign processes to more serious disorders. Performing and interpreting motility evaluations in children present unique challenges. There are primary motility disorders but abnormal motility may be secondary due to other disease processes. Diagnostic studies include radiographic scintigraphic and manometry studies. Although recent advances in the genetics, biology, and technical aspects are having an important impact and have allowed for a better understanding of the pathophysiology and therapy for gastrointestinal motility disorders in children, further research is needed to be done to have better understanding of the pathophysiology and for better therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Poly-γ-glutamic acid productivity of Bacillus subtilis BsE1 has positive function in motility and biocontrol against Fusarium graminearum.

    Science.gov (United States)

    Wang, Luyao; Wang, Ning; Mi, Dandan; Luo, Yuming; Guo, Jianhua

    2017-07-01

    In this study, we investigate the relationship between γ-PGA productivity and biocontrol capacity of Bacillus subtilis BsE1; one bacterial isolate displayed 62.14% biocontrol efficacy against Fusarium root rot. The γ-PGA yield assay, motility assay, wheat root colonization assay, and biological control assay were analysed in different γ-PGA yield mutants of BsE1. The pgsB (PGA-synthase-CapB gene) deleted mutant of BsE1 reduced γ-PGA yield and exhibited apparent decline of in vitro motile ability. Deletion of pgsB impaired colonizing capacity of BsE1 on wheat root in 30 days, also lowered biocontrol efficacies from 62.08% (wild type BsE1) to 14.22% in greenhouse experiment against Fusarium root rot. The knockout of pgdS and ggt (genes relate to two γ-PGA degrading enzymes) on BsE1, leads to a considerable improvement in polymer yield and biocontrol efficacy, which attains higher level compared with wild type BsE1. Compared with ΔpgsB mutant, defense genes related to reactive oxygen species (ROS) and phytoalexin expressed changes by notable levels on wheat roots treated with BsE1, demonstrating the functional role γ-PGA plays in biocontrol against Fusarium root rot. γ-PGA is not only important to the motile and plant root colonization ability of BsE1, but also essential to the biological control performed by BsE1 against Fusarium root rot. Our goal in this study is to reveals a new perspective of BCAs screening on bacterial isolates, without good performance during pre-assays of antagonism ability.

  12. Cell patch seeding and functional analysis of cellularized scaffolds for tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P R Anil [Division of Implant Biology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala 695012 (India); Varma, H K [Bioceramics Laboratory, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala 695012 (India); Kumary, T V [Division of Implant Biology, Biomedical Technology Wing, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala 695012 (India)

    2007-03-01

    Cell seeding has a direct impact on the final structure and function of tissue constructs, especially for applications like tissue engineering and regeneration. In this study seeding cell patches retrieved from the thermoresponsive poly(N-isopropylacrylamide) surface were used to generate in vitro tissue constructs. Porous and dense bone substitute materials were cellularized using osteoblast cells by a patch transfer and a trypsin method. The function and proliferation of cells was analyzed after 7 days of culture. The relative cell growth rate was found to be higher in cellularized porous hydroxyapatite (PHA) than in dense hydroxyapatite. Live-dead staining confirmed viable cells inside the pores of PHA. Increased alkaline phosphatase activity of cells transferred by the cell patch over the trypsin method revealed the significance of cell patch seeding. This novel method of generating tissue constructs by cell patch seeding was successful in cellularizing scaffolds with intact cell function.

  13. Cell patch seeding and functional analysis of cellularized scaffolds for tissue engineering

    International Nuclear Information System (INIS)

    Kumar, P R Anil; Varma, H K; Kumary, T V

    2007-01-01

    Cell seeding has a direct impact on the final structure and function of tissue constructs, especially for applications like tissue engineering and regeneration. In this study seeding cell patches retrieved from the thermoresponsive poly(N-isopropylacrylamide) surface were used to generate in vitro tissue constructs. Porous and dense bone substitute materials were cellularized using osteoblast cells by a patch transfer and a trypsin method. The function and proliferation of cells was analyzed after 7 days of culture. The relative cell growth rate was found to be higher in cellularized porous hydroxyapatite (PHA) than in dense hydroxyapatite. Live-dead staining confirmed viable cells inside the pores of PHA. Increased alkaline phosphatase activity of cells transferred by the cell patch over the trypsin method revealed the significance of cell patch seeding. This novel method of generating tissue constructs by cell patch seeding was successful in cellularizing scaffolds with intact cell function

  14. Entry of Porphyromonas gingivalis Outer Membrane Vesicles into Epithelial Cells Causes Cellular Functional Impairment▿

    Science.gov (United States)

    Furuta, Nobumichi; Takeuchi, Hiroki; Amano, Atsuo

    2009-01-01

    Porphyromonas gingivalis, a periodontal pathogen, secretes outer membrane vesicles (MVs) that contain major virulence factors, including proteases termed gingipains (Arg-gingipain [Rgp] and Lys-gingipain [Kgp]). We recently showed that P. gingivalis MVs swiftly enter host epithelial cells via an endocytosis pathway and are finally sorted to lytic compartments. However, it remains unknown whether MV entry impairs cellular function. Herein, we analyzed cellular functional impairment following entry of P. gingivalis into epithelial cells, including HeLa and immortalized human gingival epithelial (IHGE) cells. After being taken up by endocytic vacuoles, MVs degraded the cellular transferrin receptor (TfR) and integrin-related signaling molecules, such as paxillin and focal adhesion kinase (FAK), which resulted in depletion of intracellular transferrin and inhibition of cellular migration. Few Rgp-null MVs entered the cells, and these negligibly degraded TfR, whereas paxillin and FAK degradation was significant. In contrast, Kgp-null MVs clearly entered the cells and degraded TfR, while they scarcely degraded paxillin and FAK. In addition, both wild-type and Kgp-null MVs significantly impaired cellular migration, whereas the effect of Rgp-null MVs was limited. Our findings suggest that, following entry of P. gingivalis MVs into host cells, MV-associated gingipains degrade cellular functional molecules such as TfR and paxillin/FAK, resulting in cellular impairment, indicating that P. gingivalis MVs are potent vehicles for transmission of virulence factors into host cells and are involved in the etiology of periodontitis. PMID:19737899

  15. Asian motility studies in irritable bowel syndrome.

    Science.gov (United States)

    Lee, Oh Young

    2010-04-01

    Altered motility remains one of the important pathophysiologic factors in patients with irritable bowel syndrome (IBS) who commonly complain of abdominal pain and stool changes such as diarrhea and constipation. The prevalence of IBS has increased among Asian populations these days. Gastrointestinal (GI) physiology may vary between Asian and Western populations because of differences in diets, socio-cultural backgrounds, and genetic factors. The characteristics and differences of GI dysmotility in Asian IBS patients were reviewed. MEDLINE search work was performed including following terms, 'IBS,' 'motility,' 'transit time,' 'esophageal motility,' 'gastric motility,' 'small intestinal motility,' 'colonic motility,' 'anorectal function,' and 'gallbladder motility' and over 100 articles were categorized under 'esophagus,' 'stomach,' 'small intestine,' 'colon,' 'anorectum,' 'gallbladder,' 'transit,' 'motor pattern,' and 'effect of stressors.' Delayed gastric emptying, slow tansit in constipation predominant IBS patients, rapid transit in diarrhea predominant IBS patients, accelerated motility responses to various stressors such as meals, mental stress, or corticotrophin releasing hormones, and altered rectal compliance and altered rectal accomodation were reported in many Asian studies regarding IBS. Many conflicting results were found among these studies and there are still controversies to conclude these as unique features of Asian IBS patients. Multinational and multicenter studies are needed to be performed vigorously in order to elaborate characteristics as well as differences of altered motililty in Asian patients with IBS.

  16. Chronic Lymphocytic Leukemia B-Cell Normal Cellular Counterpart: Clues From a Functional Perspective.

    Science.gov (United States)

    Darwiche, Walaa; Gubler, Brigitte; Marolleau, Jean-Pierre; Ghamlouch, Hussein

    2018-01-01

    Chronic lymphocytic leukemia (CLL) is characterized by the clonal expansion of small mature-looking CD19+ CD23+ CD5+ B-cells that accumulate in the blood, bone marrow, and lymphoid organs. To date, no consensus has been reached concerning the normal cellular counterpart of CLL B-cells and several B-cell types have been proposed. CLL B-cells have remarkable phenotypic and gene expression profile homogeneity. In recent years, the molecular and cellular biology of CLL has been enriched by seminal insights that are leading to a better understanding of the natural history of the disease. Immunophenotypic and molecular approaches (including immunoglobulin heavy-chain variable gene mutational status, transcriptional and epigenetic profiling) comparing the normal B-cell subset and CLL B-cells provide some new insights into the normal cellular counterpart. Functional characteristics (including activation requirements and propensity for plasma cell differentiation) of CLL B-cells have now been investigated for 50 years. B-cell subsets differ substantially in terms of their functional features. Analysis of shared functional characteristics may reveal similarities between normal B-cell subsets and CLL B-cells, allowing speculative assignment of a normal cellular counterpart for CLL B-cells. In this review, we summarize current data regarding peripheral B-cell differentiation and human B-cell subsets and suggest possibilities for a normal cellular counterpart based on the functional characteristics of CLL B-cells. However, a definitive normal cellular counterpart cannot be attributed on the basis of the available data. We discuss the functional characteristics required for a cell to be logically considered to be the normal counterpart of CLL B-cells.

  17. Leading research on artificial techniques controlling cellular function; Saibo zoshoku seigyo gijutsu no sendo kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Advanced research and its applicability were surveyed to apply the advanced functional cells to industry. The basic target was set to develop, produce, control and utilize the functional cells, such as intelligent materials and self-regulation bioreactors. The regulation factors regarding apotosis, which is a process of cell suicide programmed within the cell itself of multicellular organisms, cell cycle and aging/ageless were investigated. Furthermore, the function of regulatory factors was investigated at the protein level. Injection of factors regulating cellular function and tissue engineering required for the regulation of cell proliferation were investigated. Tissue engineering is considered to be the intracellular regulation by gene transduction and the extracellular regulation by culture methods, such as coculture. Analysis methods for cell proliferation and function of living cells were investigated using the probes recognizing molecular structure. Novel biomaterials, artificial organ systems, cellular therapy and useful materials were investigated for utilizing the regulation techniques of cell proliferation. 425 refs., 85 figs., 9 tabs.

  18. The FPGA realization of the general cellular automata based cryptographic hash functions: Performance and effectiveness

    Directory of Open Access Journals (Sweden)

    P. G. Klyucharev

    2014-01-01

    Full Text Available In the paper the author considers hardware implementation of the GRACE-H family general cellular automata based cryptographic hash functions. VHDL is used as a language and Altera FPGA as a platform for hardware implementation. Performance and effectiveness of the FPGA implementations of GRACE-H hash functions were compared with Keccak (SHA-3, SHA-256, BLAKE, Groestl, JH, Skein hash functions. According to the performed tests, performance of the hardware implementation of GRACE-H family hash functions significantly (up to 12 times exceeded performance of the hardware implementation of previously known hash functions, and effectiveness of that hardware implementation was also better (up to 4 times.

  19. Activation Mechanism of LRRK2 and Its Cellular Functions in Parkinson's Disease

    NARCIS (Netherlands)

    Rosenbusch, Katharina E.; Kortholt, Arjan

    2016-01-01

    Human LRRK2 (Leucine-Rich Repeat Kinase 2) has been associated with both familial and idiopathic Parkinson's disease (PD). Although several LRRK2 mediated pathways and interaction partners have been identified, the cellular functions of LRRK2 and LRRK2 mediated progression of PD are still only

  20. E3Net: a system for exploring E3-mediated regulatory networks of cellular functions.

    Science.gov (United States)

    Han, Youngwoong; Lee, Hodong; Park, Jong C; Yi, Gwan-Su

    2012-04-01

    Ubiquitin-protein ligase (E3) is a key enzyme targeting specific substrates in diverse cellular processes for ubiquitination and degradation. The existing findings of substrate specificity of E3 are, however, scattered over a number of resources, making it difficult to study them together with an integrative view. Here we present E3Net, a web-based system that provides a comprehensive collection of available E3-substrate specificities and a systematic framework for the analysis of E3-mediated regulatory networks of diverse cellular functions. Currently, E3Net contains 2201 E3s and 4896 substrates in 427 organisms and 1671 E3-substrate specific relations between 493 E3s and 1277 substrates in 42 organisms, extracted mainly from MEDLINE abstracts and UniProt comments with an automatic text mining method and additional manual inspection and partly from high throughput experiment data and public ubiquitination databases. The significant functions and pathways of the extracted E3-specific substrate groups were identified from a functional enrichment analysis with 12 functional category resources for molecular functions, protein families, protein complexes, pathways, cellular processes, cellular localization, and diseases. E3Net includes interactive analysis and navigation tools that make it possible to build an integrative view of E3-substrate networks and their correlated functions with graphical illustrations and summarized descriptions. As a result, E3Net provides a comprehensive resource of E3s, substrates, and their functional implications summarized from the regulatory network structures of E3-specific substrate groups and their correlated functions. This resource will facilitate further in-depth investigation of ubiquitination-dependent regulatory mechanisms. E3Net is freely available online at http://pnet.kaist.ac.kr/e3net.

  1. Esophageal motility in eosinophilic esophagitis.

    Science.gov (United States)

    Weiss, A H; Iorio, N; Schey, R

    2015-01-01

    Eosinophilic esophagitis (EoE) is characterized by eosinophilic infiltration of the esophagus and is a potential cause of dysphagia and food impaction, most commonly affecting young men. Esophageal manometry findings vary from normal motility to aperistalsis, simultaneous contractions, diffuse esophageal spasm, nutcracker esophagus or hypotonic lower esophageal sphincter (LES). It remains unclear whether esophageal dysmotility plays a significant role in the clinical symptoms of EoE. Our aim is to review the pathogenesis, diagnosis, and effect of treatment on esophageal dysmotility in EoE. A literature search utilizing the PubMed database was performed using keywords: eosinophilic esophagitis, esophageal dysmotility, motility, manometry, impedance planimetry, barium esophagogram, endoscopic ultrasound, and dysphagia. Fifteen studies, totaling 387 patients with eosinophilic esophagitis were identified as keeping in accordance with the aim of this study and included in this review. The occurrence of abnormal esophageal manometry was reported to be between 4 and 87% among patients with EoE. Esophageal motility studies have shown reduced distensibility, abnormal peristalsis, and hypotonicity of the LES in patients with EoE, which may also mimic other esophageal motility disorders such as achalasia or nutcracker esophagus. Studies have shown conflicting results regarding the presence of esophageal dysmotility and symptoms with some reports suggesting a higher rate of food impaction, while others report no correlation between motor function and dysphagia. Motility dysfunction of the esophagus in EoE has not been well reported in the literature and studies have reported conflicting evidence regarding the clinical significance of dysmotility seen in EoE. The correlation between esophageal dysmotility and symptoms of EoE remains unclear. Larger studies are needed to investigate the incidence of esophageal dysmotility, clinical implications, and effect of treatment on

  2. A randomized double-blind placebo-controlled crossover-style trial of buspirone in functional dysphagia and ineffective esophageal motility.

    Science.gov (United States)

    Aggarwal, Nitin; Thota, Prashanthi Nagavenkata; Lopez, Rocio; Gabbard, Scott

    2018-02-01

    Studies suggest that Ineffective Esophageal Motility (IEM) is the manometric correlate of Functional Dysphagia (FD). Currently, there is no accepted therapy for either condition. Buspirone is a serotonin modulating medication and has been shown to augment esophageal peristaltic amplitude in healthy volunteers. We aimed to determine if buspirone improves manometric parameters and symptoms in patients with overlapping IEM/FD. We performed a prospective, double-blind, placebo-controlled, crossover-style trial of 10 patients with IEM/FD. The study consisted of two 2-week treatment arms with a 2-week washout period. Outcomes measured at baseline, end of week 2, and week 6 include high resolution esophageal manometry (HREM), the Mayo Dysphagia Questionnaire-14 (MDQ-14), and the GERD-HRQL. The mean age of our 10 patients was 53 ± 9 years and 70% were female. After treatment with buspirone, 30% of patients had normalization of IEM on manometry; however, there was 30% normalization in the placebo group as well. Comparing buspirone to placebo, there was no statistically significant difference in the HREM parameters measured. There was also no statistically significant difference in symptom outcomes for buspirone compared to placebo. Of note, patients had a statistically significant decrease in the total GERD-HRQL total score when treated with placebo compared to baseline levels. Despite previous data demonstrating improved esophageal motility in healthy volunteers, our study shows no difference in terms of HREM parameters or symptom scores in IEM/FD patients treated with buspirone compared to placebo. Further research is necessary to identify novel agents for this condition. © 2017 John Wiley & Sons Ltd.

  3. Structural, biochemical, cellular, and functional changes in skeletal muscle extracellular matrix with aging

    DEFF Research Database (Denmark)

    Kragstrup, Tue Wenzel; Kjaer, M; Mackey, A L

    2011-01-01

    The extracellular matrix (ECM) of skeletal muscle is critical for force transmission and for the passive elastic response of skeletal muscle. Structural, biochemical, cellular, and functional changes in skeletal muscle ECM contribute to the deterioration in muscle mechanical properties with aging......-links and a buildup of advanced glycation end-product cross-links. Altered mechanotransduction, poorer activation of satellite cells, poorer chemotactic and delayed inflammatory responses, and a change in modulators of the ECM are important cellular changes. It is possible that the structural and biochemical changes...... in skeletal muscle ECM contribute to the increased stiffness and impairment in force generated by the contracting muscle fibers seen with aging. The cellular interactions provide and potentially coordinate an adaptation to mechanical loading and ensure successful regeneration after muscle injury. Some...

  4. Simultaneous characterization of cellular RNA structure and function with in-cell SHAPE-Seq.

    Science.gov (United States)

    Watters, Kyle E; Abbott, Timothy R; Lucks, Julius B

    2016-01-29

    Many non-coding RNAs form structures that interact with cellular machinery to control gene expression. A central goal of molecular and synthetic biology is to uncover design principles linking RNA structure to function to understand and engineer this relationship. Here we report a simple, high-throughput method called in-cell SHAPE-Seq that combines in-cell probing of RNA structure with a measurement of gene expression to simultaneously characterize RNA structure and function in bacterial cells. We use in-cell SHAPE-Seq to study the structure-function relationship of two RNA mechanisms that regulate translation in Escherichia coli. We find that nucleotides that participate in RNA-RNA interactions are highly accessible when their binding partner is absent and that changes in RNA structure due to RNA-RNA interactions can be quantitatively correlated to changes in gene expression. We also characterize the cellular structures of three endogenously expressed non-coding RNAs: 5S rRNA, RNase P and the btuB riboswitch. Finally, a comparison between in-cell and in vitro folded RNA structures revealed remarkable similarities for synthetic RNAs, but significant differences for RNAs that participate in complex cellular interactions. Thus, in-cell SHAPE-Seq represents an easily approachable tool for biologists and engineers to uncover relationships between sequence, structure and function of RNAs in the cell. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  5. [Motility disorders of the esophagus].

    Science.gov (United States)

    Bruder, E; Rougemont, A-L; Furlano, R I; Schneider, J F; Mayr, J; Haecker, F-M; Beier, K; Schneider, J; Weber, P; Berberich, T; Cathomas, G; Meier-Ruge, W A

    2013-03-01

    Motility disorders of the esophagus comprise a heterogeneous spectrum of diseases. Primary malformations of the esophagus are now amenable to improved surgical and gastroenterological therapies; however, they often lead to persistent long-term esophageal dysmotility. Achalasia originates from impaired relaxation of the gastroesophageal sphincter apparatus. Systemic diseases may give rise to secondary disorders of esophageal motility. A number of visceral neuromuscular disorders show an esophageal manifestation but aganglionosis rarely extends into the esophagus. The growing group of myopathies includes metabolic and mitochondrial disorders with increasing levels of genetic characterization and incipient emergence of therapeutic strategies. Esophagitis with an infectious etiology causes severe dysmotility particularly in immunocompromised patients. Immunologically mediated inflammatory processes involving the esophagus are increasingly better understood. Finally, rare tumors and tumor-like lesions may impair esophageal motor function.

  6. Effect of liniment levamisole on cellular immune functions of patients with chronic hepatitis B.

    Science.gov (United States)

    Wang, Ke-Xia; Zhang, Li-Hua; Peng, Jiang-Long; Liang, Yong; Wang, Xue-Feng; Zhi, Hui; Wang, Xiang-Xia; Geng, Huan-Xiong

    2005-12-07

    To explore the effects of liniment levamisole on cellular immune functions of patients with chronic hepatitis B. The levels of T lymphocyte subsets and mIL-2R in peripheral blood mononuclear cells (PBMCs) were measured by biotin-streptavidin (BSA) technique in patients with chronic hepatitis B before and after the treatment with liniment levamisole. After one course of treatment with liniment levamisole, the levels of CD3(+), CD4(+), and the ratio of CD4(+)/CD8(+) increased as compared to those before the treatment but the level of CD8(+) decreased. The total expression level of mIL-2R in PBMCs increased before and after the treatment with liniment levamisole. Liniment levamisole may reinforce cellular immune functions of patients with chronic hepatitis B.

  7. Structural, biochemical, cellular, and functional changes in skeletal muscle extracellular matrix with aging

    DEFF Research Database (Denmark)

    Kragstrup, T W; Kjaer, M; Mackey, A L

    2011-01-01

    The extracellular matrix (ECM) of skeletal muscle is critical for force transmission and for the passive elastic response of skeletal muscle. Structural, biochemical, cellular, and functional changes in skeletal muscle ECM contribute to the deterioration in muscle mechanical properties with aging....... Structural changes include an increase in the collagen concentration, a change in the elastic fiber system, and an increase in fat infiltration of skeletal muscle. Biochemical changes include a decreased turnover of collagen with potential accumulation of enzymatically mediated collagen cross...

  8. Mitochondrial PKA mediates sperm motility.

    Science.gov (United States)

    Mizrahi, Rashel; Breitbart, Haim

    2014-12-01

    Mitochondria are the major source of ATP to power sperm motility. Phosphorylation of mitochondrial proteins has been proposed as a major regulatory mechanism for mitochondrial bioenergetics. Sperm motility was measured by a computer-assisted analyzer, protein detection by western blotting, membrane potential by tetramethylrhodamine, cellular ATP by luciferase assay and localization of PKA by immuno-electron microscopy. Bicarbonate is essential for the creation of mitochondrial electro-chemical gradient, ATP synthesis and sperm motility. Bicarbonate stimulates PKA-dependent phosphorylation of two 60kDa proteins identified as Tektin and glucose-6-phosphate isomerase. This phosphorylation was inhibited by respiration inhibition and phosphorylation could be restored by glucose in the presence of bicarbonate. However, this effect of glucose cannot be seen when the mitochondrial ATP/ADP exchanger was inhibited indicating that glycolytic-produced ATP is transported into the mitochondria and allows PKA-dependent protein phosphorylation inside the mitochondria. Bicarbonate activates mitochondrial soluble adenylyl cyclase (sAC) which catalyzes cAMP production leading to the activation of mitochondrial PKA. Glucose can overcome the lack of ATP in the absence of bicarbonate but it cannot affect the mitochondrial sAC/PKA system, therefore the PKA-dependent phosphorylation of the 60kDa proteins does not occur in the absence of bicarbonate. Production of CO2 in Krebs cycle, which is converted to bicarbonate is essential for sAC/PKA activation leading to mitochondrial membrane potential creation and ATP synthesis. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. One-way hash function based on hyper-chaotic cellular neural network

    International Nuclear Information System (INIS)

    Yang Qunting; Gao Tiegang

    2008-01-01

    The design of an efficient one-way hash function with good performance is a hot spot in modern cryptography researches. In this paper, a hash function construction method based on cell neural network with hyper-chaos characteristics is proposed. First, the chaos sequence is gotten by iterating cellular neural network with Runge–Kutta algorithm, and then the chaos sequence is iterated with the message. The hash code is obtained through the corresponding transform of the latter chaos sequence. Simulation and analysis demonstrate that the new method has the merit of convenience, high sensitivity to initial values, good hash performance, especially the strong stability. (general)

  10. THE MITOCHONDRIAL PARADIGM FOR CARDIOVASCULAR DISEASE SUSCEPTIBILITY AND CELLULAR FUNCTION: A COMPLEMENTARY CONCEPT TO MENDELIAN GENETICS

    Science.gov (United States)

    Kryzwanski, David M.; Moellering, Douglas; Fetterman, Jessica L.; Dunham-Snary, Kimberly J.; Sammy, Melissa J.; Ballinger, Scott W.

    2013-01-01

    While there is general agreement that cardiovascular disease (CVD) development is influenced by a combination of genetic, environmental, and behavioral contributors, the actual mechanistic basis of how these factors initiate or promote CVD development in some individuals while others with identical risk profiles do not, is not clearly understood. This review considers the potential role for mitochondrial genetics and function in determining CVD susceptibility from the standpoint that the original features that molded cellular function were based upon mitochondrial-nuclear relationships established millions of years ago and were likely refined during prehistoric environmental selection events that today, are largely absent. Consequently, contemporary risk factors that influence our susceptibility to a variety of age-related diseases, including CVD were probably not part of the dynamics that defined the processes of mitochondrial – nuclear interaction, and thus, cell function. In this regard, the selective conditions that contributed to cellular functionality and evolution should be given more consideration when interpreting and designing experimental data and strategies. Finally, future studies that probe beyond epidemiologic associations are required. These studies will serve as the initial steps for addressing the provocative concept that contemporary human disease susceptibility is the result of selection events for mitochondrial function that increased chances for prehistoric human survival and reproductive success. PMID:21647091

  11. A global genetic interaction network maps a wiring diagram of cellular function.

    Science.gov (United States)

    Costanzo, Michael; VanderSluis, Benjamin; Koch, Elizabeth N; Baryshnikova, Anastasia; Pons, Carles; Tan, Guihong; Wang, Wen; Usaj, Matej; Hanchard, Julia; Lee, Susan D; Pelechano, Vicent; Styles, Erin B; Billmann, Maximilian; van Leeuwen, Jolanda; van Dyk, Nydia; Lin, Zhen-Yuan; Kuzmin, Elena; Nelson, Justin; Piotrowski, Jeff S; Srikumar, Tharan; Bahr, Sondra; Chen, Yiqun; Deshpande, Raamesh; Kurat, Christoph F; Li, Sheena C; Li, Zhijian; Usaj, Mojca Mattiazzi; Okada, Hiroki; Pascoe, Natasha; San Luis, Bryan-Joseph; Sharifpoor, Sara; Shuteriqi, Emira; Simpkins, Scott W; Snider, Jamie; Suresh, Harsha Garadi; Tan, Yizhao; Zhu, Hongwei; Malod-Dognin, Noel; Janjic, Vuk; Przulj, Natasa; Troyanskaya, Olga G; Stagljar, Igor; Xia, Tian; Ohya, Yoshikazu; Gingras, Anne-Claude; Raught, Brian; Boutros, Michael; Steinmetz, Lars M; Moore, Claire L; Rosebrock, Adam P; Caudy, Amy A; Myers, Chad L; Andrews, Brenda; Boone, Charles

    2016-09-23

    We generated a global genetic interaction network for Saccharomyces cerevisiae, constructing more than 23 million double mutants, identifying about 550,000 negative and about 350,000 positive genetic interactions. This comprehensive network maps genetic interactions for essential gene pairs, highlighting essential genes as densely connected hubs. Genetic interaction profiles enabled assembly of a hierarchical model of cell function, including modules corresponding to protein complexes and pathways, biological processes, and cellular compartments. Negative interactions connected functionally related genes, mapped core bioprocesses, and identified pleiotropic genes, whereas positive interactions often mapped general regulatory connections among gene pairs, rather than shared functionality. The global network illustrates how coherent sets of genetic interactions connect protein complex and pathway modules to map a functional wiring diagram of the cell. Copyright © 2016, American Association for the Advancement of Science.

  12. A global interaction network maps a wiring diagram of cellular function

    Science.gov (United States)

    Costanzo, Michael; VanderSluis, Benjamin; Koch, Elizabeth N.; Baryshnikova, Anastasia; Pons, Carles; Tan, Guihong; Wang, Wen; Usaj, Matej; Hanchard, Julia; Lee, Susan D.; Pelechano, Vicent; Styles, Erin B.; Billmann, Maximilian; van Leeuwen, Jolanda; van Dyk, Nydia; Lin, Zhen-Yuan; Kuzmin, Elena; Nelson, Justin; Piotrowski, Jeff S.; Srikumar, Tharan; Bahr, Sondra; Chen, Yiqun; Deshpande, Raamesh; Kurat, Christoph F.; Li, Sheena C.; Li, Zhijian; Usaj, Mojca Mattiazzi; Okada, Hiroki; Pascoe, Natasha; Luis, Bryan-Joseph San; Sharifpoor, Sara; Shuteriqi, Emira; Simpkins, Scott W.; Snider, Jamie; Suresh, Harsha Garadi; Tan, Yizhao; Zhu, Hongwei; Malod-Dognin, Noel; Janjic, Vuk; Przulj, Natasa; Troyanskaya, Olga G.; Stagljar, Igor; Xia, Tian; Ohya, Yoshikazu; Gingras, Anne-Claude; Raught, Brian; Boutros, Michael; Steinmetz, Lars M.; Moore, Claire L.; Rosebrock, Adam P.; Caudy, Amy A.; Myers, Chad L.; Andrews, Brenda; Boone, Charles

    2017-01-01

    We generated a global genetic interaction network for Saccharomyces cerevisiae, constructing over 23 million double mutants, identifying ~550,000 negative and ~350,000 positive genetic interactions. This comprehensive network maps genetic interactions for essential gene pairs, highlighting essential genes as densely connected hubs. Genetic interaction profiles enabled assembly of a hierarchical model of cell function, including modules corresponding to protein complexes and pathways, biological processes, and cellular compartments. Negative interactions connected functionally related genes, mapped core bioprocesses, and identified pleiotropic genes, whereas positive interactions often mapped general regulatory connections among gene pairs, rather than shared functionality. The global network illustrates how coherent sets of genetic interactions connect protein complex and pathway modules to map a functional wiring diagram of the cell. PMID:27708008

  13. Control of ciliary motility by Ca2+: Integration of Ca2+-dependent functions and targets for Ca2+ action

    International Nuclear Information System (INIS)

    Evans, T.C.

    1988-01-01

    To identify functions that regulate Ca 2+ -induced ciliary reversal in Paramecium, mutants defective in terminating depolarization-induced backward swimming were selected. Six independent recessive mutations (k-shy) comprising two complementation groups, k-shyA and k-shyB, were identified. All mutants exhibited prolonged backward swimming in depolarizing solutions. Voltage clamp studies revealed that mutant Ca 2+ current amplitudes were reduced, but could be restored to wild type levels by EGTA injection. The recovery of the mutant Ca 2+ current from Ca 2+ -dependent inactivation, and the decay of the Ca 2+ -dependent K + and Ca 2+ -dependent Na + currents after depolarization were slow in k-shy compared to wild type. To identify protein targets of Ca 2+ action, ciliary proteins that interact with calmodulin (CaM) were characterized. With a 125 I-CaM blot assay, several CaM-binding proteins were identified including axonemal, soluble, and membrane-bound polypeptides. Competitive displacement studies with unlabeled Paramecium CaM, bovine CaM, and troponinC suggested that both protein types bind CaM with high affinity and specificity. To examine the presence of CaM-binding sites in intact axonemes, a filtration binding assay was developed

  14. Hijacking of host cellular functions by an intracellular parasite, the microsporidian Anncaliia algerae.

    Directory of Open Access Journals (Sweden)

    Johan Panek

    Full Text Available Intracellular pathogens including bacteria, viruses and protozoa hijack host cell functions to access nutrients and to bypass cellular defenses and immune responses. These strategies have been acquired through selective pressure and allowed pathogens to reach an appropriate cellular niche for their survival and growth. To get new insights on how parasites hijack host cellular functions, we developed a SILAC (Stable Isotope Labeling by Amino Acids in Cell culture quantitative proteomics workflow. Our study focused on deciphering the cross-talk in a host-parasite association, involving human foreskin fibroblasts (HFF and the microsporidia Anncaliia algerae, a fungus related parasite with an obligate intracellular lifestyle and a strong host dependency. The host-parasite cross-talk was analyzed at five post-infection times 1, 6, 12 and 24 hours post-infection (hpi and 8 days post-infection (dpi. A significant up-regulation of four interferon-induced proteins with tetratricopeptide repeats IFIT1, IFIT2, IFIT3 and MX1 was observed at 8 dpi suggesting a type 1 interferon (IFN host response. Quantitative alteration of host proteins involved in biological functions such as signaling (STAT1, Ras and reduction of the translation activity (EIF3 confirmed a host type 1 IFN response. Interestingly, the SILAC approach also allowed the detection of 148 A. algerae proteins during the kinetics of infection. Among these proteins many are involved in parasite proliferation, and an over-representation of putative secreted effectors proteins was observed. Finally our survey also suggests that A. algerae could use a transposable element as a lure strategy to escape the host innate immune system.

  15. Covalent immobilization of penicillin G acylase on aminopropyl-functionalized mesostructured cellular foams.

    Science.gov (United States)

    Zhao, Junqi; Wang, Yujun; Luo, Guangsheng; Zhu, Shenlin

    2010-10-01

    Mesostructured cellular foams (MCFs) are suitable for biomolecular immobilization because of their relatively large-pore diameter and pore volume. Penicillin G acylase (PGA) was immobilized on aminopropyl-functionalized MCFs through Schiff base reaction. It is shown that PGA could be fixed more firmly through the covalent immobilization on aminopropyl-functionalized MCFs support than through the adsorption immobilization on blank MCFs. The PGA loading amount on the aminopropyl-functionalized MCFs could reach 443 mg/g (dry support), and the apparent activity could achieve up to 4138 U/g (dry support). The influence of the amount of grafted aminopropyl group was studied, and it is found that the optimal molar ratio of MCFs to APTS was 15/1; in addition, the suitable enzyme distribution density for the specific activity of the immobilized PGA was 0.7 mg enzyme per m(2) of specific area of MCFs. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Comprehensive interrogation of the cellular response to fluorescent, detonation and functionalized nanodiamonds.

    Science.gov (United States)

    Moore, Laura; Grobárová, Valéria; Shen, Helen; Man, Han Bin; Míčová, Júlia; Ledvina, Miroslav; Štursa, Jan; Nesladek, Milos; Fišerová, Anna; Ho, Dean

    2014-10-21

    Nanodiamonds (NDs) are versatile nanoparticles that are currently being investigated for a variety of applications in drug delivery, biomedical imaging and nanoscale sensing. Although initial studies indicate that these small gems are biocompatible, there is a great deal of variability in synthesis methods and surface functionalization that has yet to be evaluated. Here we present a comprehensive analysis of the cellular compatibility of an array of nanodiamond subtypes and surface functionalization strategies. These results demonstrate that NDs are well tolerated by multiple cell types at both functional and gene expression levels. In addition, ND-mediated delivery of daunorubicin is less toxic to multiple cell types than treatment with daunorubicin alone, thus demonstrating the ability of the ND agent to improve drug tolerance and decrease therapeutic toxicity. Overall, the results here indicate that ND biocompatibility serves as a promising foundation for continued preclinical investigation.

  17. Comprehensive interrogation of the cellular response to fluorescent, detonation and functionalized nanodiamonds

    Science.gov (United States)

    Moore, Laura; Grobárová, Valéria; Shen, Helen; Man, Han Bin; Míčová, Júlia; Ledvina, Miroslav; Štursa, Jan; Nesladek, Milos; Fišerová, Anna; Ho, Dean

    2014-09-01

    Nanodiamonds (NDs) are versatile nanoparticles that are currently being investigated for a variety of applications in drug delivery, biomedical imaging and nanoscale sensing. Although initial studies indicate that these small gems are biocompatible, there is a great deal of variability in synthesis methods and surface functionalization that has yet to be evaluated. Here we present a comprehensive analysis of the cellular compatibility of an array of nanodiamond subtypes and surface functionalization strategies. These results demonstrate that NDs are well tolerated by multiple cell types at both functional and gene expression levels. In addition, ND-mediated delivery of daunorubicin is less toxic to multiple cell types than treatment with daunorubicin alone, thus demonstrating the ability of the ND agent to improve drug tolerance and decrease therapeutic toxicity. Overall, the results here indicate that ND biocompatibility serves as a promising foundation for continued preclinical investigation.

  18. Cell motility assays.

    Science.gov (United States)

    Hague, Angela; Jones, Gareth E

    2008-10-01

    This report summarises practical aspects to measuring cell motility in culture. The methods described here were discussed at a 1-day European Tissue Culture Society (ETCS-UK) workshop organised by John Masters and Gareth E Jones that was held at University College London on 19th April 2007.

  19. Sphincter of Oddi motility

    DEFF Research Database (Denmark)

    Funch-Jensen, P; Ebbehøj, N

    1996-01-01

    Gastroenterology. RESULTS: The SO is a zone with an elevated basal pressure with superimposed phasic contractions. It acts mainly as a resistor in the regulation of bile flow. Neurohormonal regulation influences the motility pattern. The contractions are under the control of slow waves. Clinical subgroups show...

  20. Small intestinal motility

    NARCIS (Netherlands)

    Smout, André J. P. M.

    2004-01-01

    PURPOSE OF REVIEW: In the past year, many studies were published in which new and relevant information on small intestinal motility in humans and laboratory animals was obtained. RECENT FINDINGS: Although the reported findings are heterogeneous, some themes appear to be particularly interesting and

  1. Modeling cellular systems

    CERN Document Server

    Matthäus, Franziska; Pahle, Jürgen

    2017-01-01

    This contributed volume comprises research articles and reviews on topics connected to the mathematical modeling of cellular systems. These contributions cover signaling pathways, stochastic effects, cell motility and mechanics, pattern formation processes, as well as multi-scale approaches. All authors attended the workshop on "Modeling Cellular Systems" which took place in Heidelberg in October 2014. The target audience primarily comprises researchers and experts in the field, but the book may also be beneficial for graduate students.

  2. A viral microRNA functions as an ortholog of cellular miR-155

    Science.gov (United States)

    Gottwein, Eva; Mukherjee, Neelanjan; Sachse, Christoph; Frenzel, Corina; Majoros, William H.; Chi, Jen-Tsan A.; Braich, Ravi; Manoharan, Muthiah; Soutschek, Jürgen; Ohler, Uwe; Cullen, Bryan R.

    2008-01-01

    All metazoan eukaryotes express microRNAs (miRNAs), ∼22 nt regulatory RNAs that can repress the expression of mRNAs bearing complementary sequences1. Several DNA viruses also express miRNAs in infected cells, suggesting a role in viral replication and pathogenesis2. While specific viral miRNAs have been shown to autoregulate viral mRNAs3,4 or downregulate cellular mRNAs5,6, the function of the majority of viral miRNAs remains unknown. Here, we report that the miR-K12−11 miRNA encoded by Kaposi's Sarcoma Associated Herpesvirus (KSHV) shows significant homology to cellular miR-155, including the entire miRNA “seed” region7. Using a range of assays, we demonstrate that expression of physiological levels of miR-K12−11 or miR-155 results in the downregulation of an extensive set of common mRNA targets, including genes with known roles in cell growth regulation. Our findings indicate that viral miR-K12−11 functions as an ortholog of cellular miR-155 and has likely evolved to exploit a pre-existing gene regulatory pathway in B-cells. Moreover, the known etiological role of miR-155 in B-cell transformation8-10 suggests that miR-K12−11 may contribute to the induction of KSHV-positive B-cell tumors in infected patients. PMID:18075594

  3. Functional characterization of novel genotypes and cellular oxidative stress studies in propionic acidemia.

    Science.gov (United States)

    Gallego-Villar, Lorena; Pérez-Cerdá, Celia; Pérez, Belén; Abia, David; Ugarte, Magdalena; Richard, Eva; Desviat, Lourdes R

    2013-09-01

    Propionic acidemia (PA), caused by a deficiency of the mitochondrial biotin dependent enzyme propionyl-CoA carboxylase (PCC) is one of the most frequent organic acidurias in humans. PA is caused by mutations in either the PCCA or PCCB genes encoding the α- and β-subunits of the PCC enzyme which are assembled as an α6β6 dodecamer. In this study we have investigated the molecular basis of the defect in ten fibroblast samples from PA patients. Using homology modeling with the recently solved crystal structure of the PCC holoenzyme and a eukaryotic expression system we have analyzed the structural and functional effect of novel point mutations, also revealing a novel splice defect by minigene analysis. In addition, we have investigated the contribution of oxidative stress to cellular damage measuring reactive oxygen species (ROS) levels and apoptosis parameters in patient fibroblasts, as recent studies point to a secondary mitochondrial dysfunction as pathophysiological mechanism in this disorder. The results show an increase in intracellular ROS content compared to controls, correlating with the activation of the JNK and p38 signaling pathways. Highest ROS levels were present in cells harboring functionally null mutations, including one severe missense mutation. This work provides molecular insight into the pathogenicity of PA variants and indicates that oxidative stress may be a major contributing factor to the cellular damage, supporting the proposal of antioxidant strategies as novel supplementary therapy in this rare disease.

  4. Neurotransmitter Specific, Cellular-Resolution Functional Brain Mapping Using Receptor Coated Nanoparticles: Assessment of the Possibility

    Science.gov (United States)

    Forati, Ebrahim; Sabouni, Abas; Ray, Supriyo; Head, Brian; Schoen, Christian; Sievenpiper, Dan

    2015-01-01

    Receptor coated resonant nanoparticles and quantum dots are proposed to provide a cellular-level resolution image of neural activities inside the brain. The functionalized nanoparticles and quantum dots in this approach will selectively bind to different neurotransmitters in the extra-synaptic regions of neurons. This allows us to detect neural activities in real time by monitoring the nanoparticles and quantum dots optically. Gold nanoparticles (GNPs) with two different geometries (sphere and rod) and quantum dots (QDs) with different sizes were studied along with three different neurotransmitters: dopamine, gamma-Aminobutyric acid (GABA), and glycine. The absorption/emission spectra of GNPs and QDs before and after binding of neurotransmitters and their corresponding receptors are reported. The results using QDs and nanorods with diameter 25nm and aspect rations larger than three were promising for the development of the proposed functional brain mapping approach. PMID:26717196

  5. Nuclear import and export signals are essential for proper cellular trafficking and function of ZIC3.

    Science.gov (United States)

    Bedard, James E J; Purnell, Jennifer D; Ware, Stephanie M

    2007-01-15

    Missense, frameshift and nonsense mutations in the zinc finger transcription factor ZIC3 cause heterotaxy as well as isolated congenital heart disease. Previously, we developed transactivation and subcellular localization assays to test the function of ZIC3 point mutations. Aberrant cytoplasmic localization suggested that the pathogenesis of ZIC3 mutations results, at least in part, from failure of appropriate cellular trafficking. To further investigate this hypothesis, the nucleocytoplasmic shuttling properties of ZIC3 have been examined. Subcellular localization assays designed to span the entire open-reading frame of wild-type and mutant ZIC3 proteins identified the presence of nucleocytoplasmic transport signals. ZIC3 domain mapping indicates that a relatively large region containing the zinc finger binding sites and a known GLI interacting domain is required for transport to the nucleus. Site-directed mutagenesis of critical residues within two putative nuclear localization signals (NLSs) leads to loss of nuclear localization. No further decrease was observed when both NLS sites were mutated, suggesting that mutation of either NLS site is sufficient for loss of importin-mediated nuclear localization. Additionally, we identify a cryptic CRM-1-dependent nuclear export signal (NES) within ZIC3, and identify a mutation within this region in a patient with heterotaxy. These results provide the first evidence that control of cellular trafficking of ZIC3 is critical for function and suggest a possible mechanism for transcriptional control during left-right patterning. Identification of mutations in mapped NLS or NES domains in heterotaxy patients demonstrates the functional importance of these domains in cardiac morphogenesis and allows for integration of structural analysis with developmental function.

  6. The absence of the luxS gene increases swimming motility and flagella synthesis in Escherichia coli K12

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Hua; Kang, Aram; Tan, Mui Hua; Qi, Xiaobao [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459 (Singapore); Chang, Matthew Wook, E-mail: Matthewchang@ntu.edu.sg [School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459 (Singapore)

    2010-10-29

    Research highlights: {yields} This paper provides the first evidence that luxS deletion enhances swimming motility and flagella synthesis in Escherichia coli K12 based on motility, transcriptome, and scanning electron microscopy analyses. {yields} A conceptual genetic regulatory network underlying the increased flagella synthesis was constructed based on the transcriptome and network component analyses, and previously known regulatory relations. {yields} The genetic regulatory network suggests that the increased flagella synthesis and motility might be contributed to by increased flhDC transcription level and/or decreased c-di-GMP concentration in luxS-deficient E. coli. -- Abstract: Despite the significant role of S-ribosylhomocysteinase (LuxS) in the activated methyl cycle pathway and quorum sensing, the connectivity between luxS and other cellular functions remains incomplete. Herein, we show that luxS deletion significantly increases swimming motility and flagella synthesis in Escherichia coli K12 using motility, transcriptome, and scanning electron microscopy assays. Further, based on the transcriptome and network component analyses, and known regulatory relations, we propose a conceptual genetic regulatory network underlying the increased flagella synthesis in response to luxS deletion.

  7. The absence of the luxS gene increases swimming motility and flagella synthesis in Escherichia coli K12

    International Nuclear Information System (INIS)

    Ling, Hua; Kang, Aram; Tan, Mui Hua; Qi, Xiaobao; Chang, Matthew Wook

    2010-01-01

    Research highlights: → This paper provides the first evidence that luxS deletion enhances swimming motility and flagella synthesis in Escherichia coli K12 based on motility, transcriptome, and scanning electron microscopy analyses. → A conceptual genetic regulatory network underlying the increased flagella synthesis was constructed based on the transcriptome and network component analyses, and previously known regulatory relations. → The genetic regulatory network suggests that the increased flagella synthesis and motility might be contributed to by increased flhDC transcription level and/or decreased c-di-GMP concentration in luxS-deficient E. coli. -- Abstract: Despite the significant role of S-ribosylhomocysteinase (LuxS) in the activated methyl cycle pathway and quorum sensing, the connectivity between luxS and other cellular functions remains incomplete. Herein, we show that luxS deletion significantly increases swimming motility and flagella synthesis in Escherichia coli K12 using motility, transcriptome, and scanning electron microscopy assays. Further, based on the transcriptome and network component analyses, and known regulatory relations, we propose a conceptual genetic regulatory network underlying the increased flagella synthesis in response to luxS deletion.

  8. Molecular design and nanoparticle-mediated intracellular delivery of functional proteins to target cellular pathways

    Science.gov (United States)

    Shah, Dhiral Ashwin

    Intracellular delivery of specific proteins and peptides represents a novel method to influence stem cells for gain-of-function and loss-of-function. Signaling control is vital in stem cells, wherein intricate control of and interplay among critical pathways directs the fate of these cells into either self-renewal or differentiation. The most common route to manipulate cellular function involves the introduction of genetic material such as full-length genes and shRNA into the cell to generate (or prevent formation of) the target protein, and thereby ultimately alter cell function. However, viral-mediated gene delivery may result in relatively slow expression of proteins and prevalence of oncogene insertion into the cell, which can alter cell function in an unpredictable fashion, and non-viral delivery may lead to low efficiency of genetic delivery. For example, the latter case plagues the generation of induced pluripotent stem cells (iPSCs) and hinders their use for in vivo applications. Alternatively, introducing proteins into cells that specifically recognize and influence target proteins, can result in immediate deactivation or activation of key signaling pathways within the cell. In this work, we demonstrate the cellular delivery of functional proteins attached to hydrophobically modified silica (SiNP) nanoparticles to manipulate specifically targeted cell signaling proteins. In the Wnt signaling pathway, we have targeted the phosphorylation activity of glycogen synthase kinase-3beta (GSK-3beta) by designing a chimeric protein and delivering it in neural stem cells. Confocal imaging indicates that the SiNP-chimeric protein conjugates were efficiently delivered to the cytosol of human embryonic kidney cells and rat neural stem cells, presumably via endocytosis. This uptake impacted the Wnt signaling cascade, indicated by the elevation of beta-catenin levels, and increased transcription of Wnt target genes, such as c-MYC. The results presented here suggest that

  9. Viral and cellular SOS-regulated motor proteins: dsDNA translocation mechanisms with divergent functions.

    Science.gov (United States)

    Wolfe, Annie; Phipps, Kara; Weitao, Tao

    2014-01-01

    DNA damage attacks on bacterial cells have been known to activate the SOS response, a transcriptional response affecting chromosome replication, DNA recombination and repair, cell division and prophage induction. All these functions require double-stranded (ds) DNA translocation by ASCE hexameric motors. This review seeks to delineate the structural and functional characteristics of the SOS response and the SOS-regulated DNA translocases FtsK and RuvB with the phi29 bacteriophage packaging motor gp16 ATPase as a prototype to study bacterial motors. While gp16 ATPase, cellular FtsK and RuvB are similarly comprised of hexameric rings encircling dsDNA and functioning as ATP-driven DNA translocases, they utilize different mechanisms to accomplish separate functions, suggesting a convergent evolution of these motors. The gp16 ATPase and FtsK use a novel revolution mechanism, generating a power stroke between subunits through an entropy-DNA affinity switch and pushing dsDNA inward without rotation of DNA and the motor, whereas RuvB seems to employ a rotation mechanism that remains to be further characterized. While FtsK and RuvB perform essential tasks during the SOS response, their roles may be far more significant as SOS response is involved in antibiotic-inducible bacterial vesiculation and biofilm formation as well as the perspective of the bacteria-cancer evolutionary interaction.

  10. Contact- and Protein Transfer-Dependent Stimulation of Assembly of the Gliding Motility Machinery in Myxococcus xanthus.

    Directory of Open Access Journals (Sweden)

    Beata Jakobczak

    2015-07-01

    Full Text Available Bacteria engage in contact-dependent activities to coordinate cellular activities that aid their survival. Cells of Myxococcus xanthus move over surfaces by means of type IV pili and gliding motility. Upon direct contact, cells physically exchange outer membrane (OM lipoproteins, and this transfer can rescue motility in mutants lacking lipoproteins required for motility. The mechanism of gliding motility and its stimulation by transferred OM lipoproteins remain poorly characterized. We investigated the function of CglC, GltB, GltA and GltC, all of which are required for gliding. We demonstrate that CglC is an OM lipoprotein, GltB and GltA are integral OM β-barrel proteins, and GltC is a soluble periplasmic protein. GltB and GltA are mutually stabilizing, and both are required to stabilize GltC, whereas CglC accumulate independently of GltB, GltA and GltC. Consistently, purified GltB, GltA and GltC proteins interact in all pair-wise combinations. Using active fluorescently-tagged fusion proteins, we demonstrate that GltB, GltA and GltC are integral components of the gliding motility complex. Incorporation of GltB and GltA into this complex depends on CglC and GltC as well as on the cytoplasmic AglZ protein and the inner membrane protein AglQ, both of which are components of the gliding motility complex. Conversely, incorporation of AglZ and AglQ into the gliding motility complex depends on CglC, GltB, GltA and GltC. Remarkably, physical transfer of the OM lipoprotein CglC to a ΔcglC recipient stimulates assembly of the gliding motility complex in the recipient likely by facilitating the OM integration of GltB and GltA. These data provide evidence that the gliding motility complex in M. xanthus includes OM proteins and suggest that this complex extends from the cytoplasm across the cell envelope to the OM. These data add assembly of gliding motility complexes in M. xanthus to the growing list of contact-dependent activities in bacteria.

  11. Does Hypothyroidism Affect Gastrointestinal Motility?

    Directory of Open Access Journals (Sweden)

    Olga Yaylali

    2009-01-01

    Full Text Available Background. Gastrointestinal motility and serum thyroid hormone levels are closely related. Our aim was to analyze whether there is a disorder in esophagogastric motor functions as a result of hypothyroidism. Materials and Methods. The study group included 30 females (mean age ± SE 45.17 ± 2.07 years with primary hypothyroidism and 10 healthy females (mean age ± SE 39.40 ± 3.95 years. All cases underwent esophagogastric endoscopy and scintigraphy. For esophageal scintigraphy, dynamic imaging of esophagus motility protocol, and for gastric emptying scintigraphy, anterior static gastric images were acquired. Results. The mean esophageal transit time (52.56 ± 4.07 sec for patients; 24.30 ± 5.88 sec for controls; P=.02 and gastric emptying time (49.06 ± 4.29 min for the hypothyroid group; 30.4 ± 4.74 min for the control group; P=.01 were markedly increased in cases of hypothyroidism. Conclusion. Hypothyroidism prominently reduces esophageal and gastric motor activity and can cause gastrointestinal dysfunction.

  12. Epoxy-functionalized mesostructured cellular foams as effective support for covalent immobilization of penicillin G acylase

    Science.gov (United States)

    Xue, Ping; Xu, Fang; Xu, Lidong

    2008-12-01

    The epoxy-functionalized mesoporous cellular foams (G-MCFs) with high specific surface area (˜400 m 2/g) and large-size mesopores (˜17 nm) were obtained by condensation of 3-glycidoxypropyltriethoxysilane (GPTS) and the surface silanol groups of mesoporous cellular foams (MCFs) and used as the support for immobilization of penicillin G acylase (PGA). The structural properties of G-MCF were characterized by FT-IR, N 2 adsorption, TG-DTA and 29Si MAS NMR. The studies indicated that the glycidoxypropyl groups were chemically bonded to the silicon atoms on the surface of MCF. The epoxy-functionalized mesoporous cellular foams can provide the microenvironments suitable for the immobilization of PGA, and the enzyme molecules could be immobilized covalently onto the G-MCF under mild conditions by reaction between the amino groups of the enzyme molecules and the epoxy groups on the surface of G-MCF. The PGA immobilized on G-MCF (PGA/G-MCF) exhibited the apparent activity of 1782 IU/g and 46.6% of activity recovery for hydrolyzing penicillin G potassium to produce 6-aminopenicillanic acid at 37 °C which were higher than that of PGA on pure silica MCF (1521 IU/g and 39.8%, respectively). The kinetic study also indicated that PGA immobilized on G-MCF has a Km of 2.1 × 10 -2 mol/L lower than that of PGA immobilized on the pure silica MCF (5.0 × 10 -2 mol/L). These may be attributed to the enhanced surface affinity between G-MCF support and the substrate molecules. Due to the covalent immobilization of PGA molecules on the surface of G-MCF, the immobilized PGA with considerable operational stability was achieved. The activity of PGA/G-MCF is still about 91.4% of its initial activity at the 10th cycle reuse while that of PGA/MCF only remains 41.5% of its initial activity at the same reuse numbers. In addition, the investigation results show the thermal stability and durability on acid or basic medium of PGA immobilized on G-MCF were improved remarkably.

  13. Epoxy-functionalized mesostructured cellular foams as effective support for covalent immobilization of penicillin G acylase

    International Nuclear Information System (INIS)

    Xue Ping; Xu Fang; Xu Lidong

    2008-01-01

    The epoxy-functionalized mesoporous cellular foams (G-MCFs) with high specific surface area (∼400 m 2 /g) and large-size mesopores (∼17 nm) were obtained by condensation of 3-glycidoxypropyltriethoxysilane (GPTS) and the surface silanol groups of mesoporous cellular foams (MCFs) and used as the support for immobilization of penicillin G acylase (PGA). The structural properties of G-MCF were characterized by FT-IR, N 2 adsorption, TG-DTA and 29 Si MAS NMR. The studies indicated that the glycidoxypropyl groups were chemically bonded to the silicon atoms on the surface of MCF. The epoxy-functionalized mesoporous cellular foams can provide the microenvironments suitable for the immobilization of PGA, and the enzyme molecules could be immobilized covalently onto the G-MCF under mild conditions by reaction between the amino groups of the enzyme molecules and the epoxy groups on the surface of G-MCF. The PGA immobilized on G-MCF (PGA/G-MCF) exhibited the apparent activity of 1782 IU/g and 46.6% of activity recovery for hydrolyzing penicillin G potassium to produce 6-aminopenicillanic acid at 37 o C which were higher than that of PGA on pure silica MCF (1521 IU/g and 39.8%, respectively). The kinetic study also indicated that PGA immobilized on G-MCF has a K m of 2.1 x 10 -2 mol/L lower than that of PGA immobilized on the pure silica MCF (5.0 x 10 -2 mol/L). These may be attributed to the enhanced surface affinity between G-MCF support and the substrate molecules. Due to the covalent immobilization of PGA molecules on the surface of G-MCF, the immobilized PGA with considerable operational stability was achieved. The activity of PGA/G-MCF is still about 91.4% of its initial activity at the 10th cycle reuse while that of PGA/MCF only remains 41.5% of its initial activity at the same reuse numbers. In addition, the investigation results show the thermal stability and durability on acid or basic medium of PGA immobilized on G-MCF were improved remarkably.

  14. Epoxy-functionalized mesostructured cellular foams as effective support for covalent immobilization of penicillin G acylase

    Energy Technology Data Exchange (ETDEWEB)

    Xue Ping [Key Laboratory of Energy Resources and Chemical Engineering, Ningxia University, Yinchuan 750021 (China)], E-mail: Ping@nxu.edu.cn; Xu Fang [Department of Molecule Biology, Ningxia Medical College, Yinchuan 750021 (China); Xu Lidong [Key Laboratory of Energy Resources and Chemical Engineering, Ningxia University, Yinchuan 750021 (China)

    2008-12-30

    The epoxy-functionalized mesoporous cellular foams (G-MCFs) with high specific surface area ({approx}400 m{sup 2}/g) and large-size mesopores ({approx}17 nm) were obtained by condensation of 3-glycidoxypropyltriethoxysilane (GPTS) and the surface silanol groups of mesoporous cellular foams (MCFs) and used as the support for immobilization of penicillin G acylase (PGA). The structural properties of G-MCF were characterized by FT-IR, N{sub 2} adsorption, TG-DTA and {sup 29}Si MAS NMR. The studies indicated that the glycidoxypropyl groups were chemically bonded to the silicon atoms on the surface of MCF. The epoxy-functionalized mesoporous cellular foams can provide the microenvironments suitable for the immobilization of PGA, and the enzyme molecules could be immobilized covalently onto the G-MCF under mild conditions by reaction between the amino groups of the enzyme molecules and the epoxy groups on the surface of G-MCF. The PGA immobilized on G-MCF (PGA/G-MCF) exhibited the apparent activity of 1782 IU/g and 46.6% of activity recovery for hydrolyzing penicillin G potassium to produce 6-aminopenicillanic acid at 37 {sup o}C which were higher than that of PGA on pure silica MCF (1521 IU/g and 39.8%, respectively). The kinetic study also indicated that PGA immobilized on G-MCF has a K{sub m} of 2.1 x 10{sup -2} mol/L lower than that of PGA immobilized on the pure silica MCF (5.0 x 10{sup -2} mol/L). These may be attributed to the enhanced surface affinity between G-MCF support and the substrate molecules. Due to the covalent immobilization of PGA molecules on the surface of G-MCF, the immobilized PGA with considerable operational stability was achieved. The activity of PGA/G-MCF is still about 91.4% of its initial activity at the 10th cycle reuse while that of PGA/MCF only remains 41.5% of its initial activity at the same reuse numbers. In addition, the investigation results show the thermal stability and durability on acid or basic medium of PGA immobilized on G

  15. Tumor suppressor KAI1 affects integrin αvβ3-mediated ovarian cancer cell adhesion, motility, and proliferation

    International Nuclear Information System (INIS)

    Ruseva, Zlatna; Geiger, Pamina Xenia Charlotte; Hutzler, Peter; Kotzsch, Matthias; Luber, Birgit; Schmitt, Manfred; Gross, Eva; Reuning, Ute

    2009-01-01

    The tetraspanin KAI1 had been described as a metastasis suppressor in many different cancer types, a function for which associations of KAI1 with adhesion and signaling receptors of the integrin superfamily likely play a role. In ovarian cancer, integrin αvβ3 correlates with tumor progression and its elevation in vitro provoked enhanced cell adhesion accompanied by significant increases in cell motility and proliferation in the presence of its major ligand vitronectin. In the present study, we characterized integrin αvβ3-mediated tumor biological effects as a function of cellular KAI1 restoration and proved for the first time that KAI1, besides its already known physical crosstalk with β1-integrins, also colocalizes with integrin αvβ3. Functionally, elevated KAI1 levels drastically increased integrin αvβ3/vitronectin-dependent ovarian cancer cell adhesion. Since an intermediate level of cell adhesive strength is required for optimal cell migration, we next studied ovarian cancer cell motility as a function of KAI1 restoration. By time lapse video microscopy, we found impaired integrin αvβ3/vitronectin-mediated cell migration most probably due to strongly enhanced cellular immobilization onto the adhesion-supporting matrix. Moreover, KAI1 reexpression significantly diminished cell proliferation. These data strongly indicate that KAI1 may suppress ovarian cancer progression by inhibiting integrin αvβ3/vitronectin-provoked tumor cell motility and proliferation as important hallmarks of the oncogenic process.

  16. The functional micro-organization of grid cells revealed by cellular-resolution imaging.

    Science.gov (United States)

    Heys, James G; Rangarajan, Krsna V; Dombeck, Daniel A

    2014-12-03

    Establishing how grid cells are anatomically arranged, on a microscopic scale, in relation to their firing patterns in the environment would facilitate a greater microcircuit-level understanding of the brain's representation of space. However, all previous grid cell recordings used electrode techniques that provide limited descriptions of fine-scale organization. We therefore developed a technique for cellular-resolution functional imaging of medial entorhinal cortex (MEC) neurons in mice navigating a virtual linear track, enabling a new experimental approach to study MEC. Using these methods, we show that grid cells are physically clustered in MEC compared to nongrid cells. Additionally, we demonstrate that grid cells are functionally micro-organized: the similarity between the environment firing locations of grid cell pairs varies as a function of the distance between them according to a "Mexican hat"-shaped profile. This suggests that, on average, nearby grid cells have more similar spatial firing phases than those further apart. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Changes in Retinal Function and Cellular Remodeling Following Experimental Retinal Detachment in a Rabbit Model

    Directory of Open Access Journals (Sweden)

    Tilda Barliya

    2017-01-01

    Full Text Available Purpose. To explore functional electroretinographic (ERG changes and associated cellular remodeling following experimental retinal detachment in a rabbit model. Methods. Retinal detachment was created in ten rabbits by injecting 0.1 ml balanced salt solution under the retina. Fundus imaging was performed 0, 3, 7, 14, and 21 days postoperatively. ERGs were recorded pre- and 7 and 21 days postoperatively. Eyes were harvested on day 21 and evaluated immunohistochemically (IHC for remodeling of second- and third-order neurons. Results. Retinal reattachment occurred within two weeks following surgery. No attenuation was observed in the photopic or scotopic a- and b-waves. A secondary wavefront on the descending slope of the scotopic b-wave was the only ERG result that was attenuated in detached retinas. IHC demonstrated anatomical changes in both ON and OFF bipolar cells. Bassoon staining was observed in the remodeled dendrites. Amacrine and horizontal cells did not alter, but Muller cells were clearly reactive with marked extension. Conclusion. Retinal detachment and reattachment were associated with functional and anatomical changes. Exploring the significance of the secondary scotopic wavefront and its association with the remodeling of 2nd- and 3rd-order neurons will shade more light on functional changes and recovery of the retina.

  18. The association between systemic inflammatory cellular levels and lung function: a population-based study.

    Directory of Open Access Journals (Sweden)

    Tricia McKeever

    Full Text Available BACKGROUND: Lower lung function is associated with an elevated systemic white cell count in men. However, these observations have not been demonstrated in a representative population that includes females and may be susceptible to confounding by recent airway infections or recent cigarette smoking. We tested the hypothesis that lung function is inversely associated with systemic white cell count in a population-based study. METHODS: The study population consisted adults aged 17-90+ years who participated in the Third National Health and Nutrition Examination Survey who did not report a recent cough, cold or acute illness in a non-smoking and smoking population. RESULTS: In non-smoking adults with the highest quintile of the total white cell count had a FEV(1 125.3 ml lower than those in the lowest quintile (95% confidence interval CI: -163.1 to -87.5. Adults with the highest quintile of the total white cell count had a FVC 151.1 ml lower than those in the lowest quintile (95% confidence interval CI: -195.0 to -107.2. Similar associations were observed for granulocytes, mononuclear cells and lymphocytes. In current smokers, similar smaller associations observed for total white cell count, granulocytes and mononuclear cells. CONCLUSIONS: Systemic cellular inflammation levels are inversely associated with lung function in a population of both non-smokers and smokers without acute illnesses. This may contribute to the increased mortality observed in individuals with a higher baseline white cell count.

  19. Mitochondrial respiratory efficiency is positively correlated with human sperm motility.

    Science.gov (United States)

    Ferramosca, Alessandra; Provenzano, Sara Pinto; Coppola, Lamberto; Zara, Vincenzo

    2012-04-01

    To correlate sperm mitochondrial respiratory efficiency with variations in sperm motility and with sperm morphologic anomalies. Sperm mitochondrial respiratory activity was evaluated with a polarographic assay of oxygen consumption carried out in hypotonically-treated sperm cells. A possible relationship among sperm mitochondrial respiratory efficiency, sperm motility, and morphologic anomalies was investigated. Mitochondrial respiratory efficiency was positively correlated with sperm motility and negatively correlated with the percentage of immotile spermatozoa. Moreover, midpiece defects impaired mitochondrial functionality. Our data indicate that an increase in sperm motility requires a parallel increase in mitochondrial respiratory capacity, thereby supporting the fundamental role played by mitochondrial oxidative phosphorylation in sperm motility of normozoospermic subjects. These results are of physiopathological relevance because they suggest that disturbances of sperm mitochondrial function and of energy production could be responsible for asthenozoospermia. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Effects of HIV-1 protease on cellular functions and their potential applications in antiretroviral therapy

    Directory of Open Access Journals (Sweden)

    Yang Hailiu

    2012-09-01

    fission yeast as a possible surrogate system to study the effects of HIV-1 protease on cellular functions and to explore its utility as a HTS system to search for new PIs to battle HIV-1 resistant strains.

  1. Distinct Residues Contribute to Motility Repression and Autoregulation in the Proteus mirabilis Fimbria-Associated Transcriptional Regulator AtfJ.

    Science.gov (United States)

    Bode, Nadine J; Chan, Kun-Wei; Kong, Xiang-Peng; Pearson, Melanie M

    2016-08-01

    Proteus mirabilis contributes to a significant number of catheter-associated urinary tract infections, where coordinated regulation of adherence and motility is critical for ascending disease progression. Previously, the mannose-resistant Proteus-like (MR/P) fimbria-associated transcriptional regulator MrpJ has been shown to both repress motility and directly induce the transcription of its own operon; in addition, it affects the expression of a wide range of cellular processes. Interestingly, 14 additional mrpJ paralogs are included in the P. mirabilis genome. Looking at a selection of MrpJ paralogs, we discovered that these proteins, which consistently repress motility, also have nonidentical functions that include cross-regulation of fimbrial operons. A subset of paralogs, including AtfJ (encoded by the ambient temperature fimbrial operon), Fim8J, and MrpJ, are capable of autoinduction. We identified an element of the atf promoter extending from 487 to 655 nucleotides upstream of the transcriptional start site that is responsive to AtfJ, and we found that AtfJ directly binds this fragment. Mutational analysis of AtfJ revealed that its two identified functions, autoregulation and motility repression, are not invariably linked. Residues within the DNA-binding helix-turn-helix domain are required for motility repression but not necessarily autoregulation. Likewise, the C-terminal domain is dispensable for motility repression but is essential for autoregulation. Supported by a three-dimensional (3D) structural model, we hypothesize that the C-terminal domain confers unique regulatory capacities on the AtfJ family of regulators. Balancing adherence with motility is essential for uropathogens to successfully establish a foothold in their host. Proteus mirabilis uses a fimbria-associated transcriptional regulator to switch between these antagonistic processes by increasing fimbrial adherence while simultaneously downregulating flagella. The discovery of multiple

  2. Circulating Cellular Adhesion Molecules and Cognitive Function: The Coronary Artery Risk Development in Young Adults Study

    Directory of Open Access Journals (Sweden)

    Cynthia Yursun Yoon

    2017-05-01

    Full Text Available ObjectiveHigher circulating concentrations of cellular adhesion molecules (CAMs can be used as markers of endothelial dysfunction. Given that the brain is highly vascularized, we assessed whether endothelial function is associated with cognitive performance.MethodWithin the Coronary Artery Risk Development in Young Adults (CARDIA Study, excluding N = 54 with stroke before year 25, we studied CAMs among N = 2,690 black and white men and women in CARDIA year 7 (1992–1993, ages 25–37 and N = 2,848 in CARDIA year 15 (2000–2001, ages 33–45. We included subjects with levels of circulating soluble CAMs measured in year 7 or 15 and cognitive function testing in year 25 (2010–2011, ages 43–55. Using multiple regression analysis, we evaluated the association between CAMs and year 25 cognitive test scores: Rey Auditory Verbal Learning Test (RAVLT, memory, Digit Symbol Substitution Test (DSST, speed of processing, and the Stroop Test (executive function.ResultAll CAM concentrations were greater in year 15 vs. year 7. Adjusting for age, race, sex, education, smoking, alcohol, diet, physical activity, participants in the fourth vs. the first quartile of CARDIA year 7 of circulating intercellular adhesion molecule-1 (ICAM-1 scored worse on RAVLT, DSST, and Stroop Test (p ≤ 0.05 in CARDIA year 25. Other CAMs showed little association with cognitive test scores. Findings were similar for ICAM-1 assessed at year 15. Adjustment for possibly mediating physical factors attenuated the findings.ConclusionHigher circulating ICAM-1 at average ages 32 and 40 was associated with lower cognitive skills at average age 50. The study is consistent with the hypothesis that endothelial dysfunction is associated with worse short-term memory, speed of processing, and executive function.

  3. Circulating Cellular Adhesion Molecules and Cognitive Function: The Coronary Artery Risk Development in Young Adults Study.

    Science.gov (United States)

    Yoon, Cynthia Yursun; Steffen, Lyn M; Gross, Myron D; Launer, Lenore J; Odegaard, Andrew; Reiner, Alexander; Sanchez, Otto; Yaffe, Kristine; Sidney, Stephen; Jacobs, David R

    2017-01-01

    Higher circulating concentrations of cellular adhesion molecules (CAMs) can be used as markers of endothelial dysfunction. Given that the brain is highly vascularized, we assessed whether endothelial function is associated with cognitive performance. Within the Coronary Artery Risk Development in Young Adults (CARDIA) Study, excluding N  = 54 with stroke before year 25, we studied CAMs among N  = 2,690 black and white men and women in CARDIA year 7 (1992-1993, ages 25-37) and N  = 2,848 in CARDIA year 15 (2000-2001, ages 33-45). We included subjects with levels of circulating soluble CAMs measured in year 7 or 15 and cognitive function testing in year 25 (2010-2011, ages 43-55). Using multiple regression analysis, we evaluated the association between CAMs and year 25 cognitive test scores: Rey Auditory Verbal Learning Test (RAVLT, memory), Digit Symbol Substitution Test (DSST, speed of processing), and the Stroop Test (executive function). All CAM concentrations were greater in year 15 vs. year 7. Adjusting for age, race, sex, education, smoking, alcohol, diet, physical activity, participants in the fourth vs. the first quartile of CARDIA year 7 of circulating intercellular adhesion molecule-1 (ICAM-1) scored worse on RAVLT, DSST, and Stroop Test ( p  ≤ 0.05) in CARDIA year 25. Other CAMs showed little association with cognitive test scores. Findings were similar for ICAM-1 assessed at year 15. Adjustment for possibly mediating physical factors attenuated the findings. Higher circulating ICAM-1 at average ages 32 and 40 was associated with lower cognitive skills at average age 50. The study is consistent with the hypothesis that endothelial dysfunction is associated with worse short-term memory, speed of processing, and executive function.

  4. Effects of radiofrequency radiation emitted by cellular telephones on the cognitive functions of humans.

    Science.gov (United States)

    Eliyahu, Ilan; Luria, Roy; Hareuveny, Ronen; Margaliot, Menachem; Meiran, Nachshon; Shani, Gad

    2006-02-01

    The present study examined the effects of exposure to Electromagnetic Radiation emitted by a standard GSM phone at 890 MHz on human cognitive functions. This study attempted to establish a connection between the exposure of a specific area of the brain and the cognitive functions associated with that area. A total of 36 healthy right-handed male subjects performed four distinct cognitive tasks: spatial item recognition, verbal item recognition, and two spatial compatibility tasks. Tasks were chosen according to the brain side they are assumed to activate. All subjects performed the tasks under three exposure conditions: right side, left side, and sham exposure. The phones were controlled by a base station simulator and operated at their full power. We have recorded the reaction times (RTs) and accuracy of the responses. The experiments consisted of two sections, of 1 h each, with a 5 min break in between. The tasks and the exposure regimes were counterbalanced. The results indicated that the exposure of the left side of the brain slows down the left-hand response time, in the second-later-part of the experiment. This effect was apparent in three of the four tasks, and was highly significant in only one of the tests. The exposure intensity and its duration exceeded the common exposure of cellular phone users.

  5. Cocaine and MDMA Induce Cellular and Molecular Changes in Adult Neurogenic Systems: Functional Implications

    Directory of Open Access Journals (Sweden)

    Vivian Capilla-Gonzalez

    2011-06-01

    Full Text Available The capacity of the brain to generate new adult neurons is a recent discovery that challenges the old theory of an immutable adult brain. A new and fascinating field of research now focuses on this regenerative process. The two brain systems that constantly produce new adult neurons, known as the adult neurogenic systems, are the dentate gyrus (DG of the hippocampus and the lateral ventricules/olfactory bulb system. Both systems are involved in memory and learning processes. Different drugs of abuse, such as cocaine and MDMA, have been shown to produce cellular and molecular changes that affect adult neurogenesis. This review summarizes the effects that these drugs have on the adult neurogenic systems. The functional relevance of adult neurogenesis is obscured by the functions of the systems that integrate adult neurons. Therefore, we explore the effects that cocaine and MDMA produce not only on adult neurogenesis, but also on the DG and olfactory bulbs. Finally, we discuss the possible role of new adult neurons in cocaine- and MDMA-induced impairments. We conclude that, although harmful drug effects are produced at multiple physiological and anatomical levels, the specific consequences of reduced hippocampus neurogenesis are unclear and require further exploration.

  6. Insights into the cellular function of YhdE, a nucleotide pyrophosphatase from Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Jin Jin

    Full Text Available YhdE, a Maf-like protein in Escherichia coli, exhibits nucleotide pyrophosphatase (PPase activity, yet its cellular function remains unknown. Here, we characterized the PPase activity of YhdE on dTTP, UTP and TTP and determined two crystal structures of YhdE, revealing 'closed' and 'open' conformations of an adaptive active site. Our functional studies demonstrated that YhdE retards cell growth by prolonging the lag and log phases, particularly under stress conditions. Morphology studies showed that yhdE-knockout cells transformed the normal rod shape of wild-type cells to a more spherical form, and the cell wall appeared to become more flexible. In contrast, YhdE overexpression resulted in filamentous cells. This study reveals the previously unknown involvement of YhdE in cell growth inhibition under stress conditions, cell-division arrest and cell-shape maintenance, highlighting YhdE's important role in E. coli cell-cycle checkpoints.

  7. Leukocyte Motility Models Assessed through Simulation and Multi-objective Optimization-Based Model Selection.

    Directory of Open Access Journals (Sweden)

    Mark N Read

    2016-09-01

    Full Text Available The advent of two-photon microscopy now reveals unprecedented, detailed spatio-temporal data on cellular motility and interactions in vivo. Understanding cellular motility patterns is key to gaining insight into the development and possible manipulation of the immune response. Computational simulation has become an established technique for understanding immune processes and evaluating hypotheses in the context of experimental data, and there is clear scope to integrate microscopy-informed motility dynamics. However, determining which motility model best reflects in vivo motility is non-trivial: 3D motility is an intricate process requiring several metrics to characterize. This complicates model selection and parameterization, which must be performed against several metrics simultaneously. Here we evaluate Brownian motion, Lévy walk and several correlated random walks (CRWs against the motility dynamics of neutrophils and lymph node T cells under inflammatory conditions by simultaneously considering cellular translational and turn speeds, and meandering indices. Heterogeneous cells exhibiting a continuum of inherent translational speeds and directionalities comprise both datasets, a feature significantly improving capture of in vivo motility when simulated as a CRW. Furthermore, translational and turn speeds are inversely correlated, and the corresponding CRW simulation again improves capture of our in vivo data, albeit to a lesser extent. In contrast, Brownian motion poorly reflects our data. Lévy walk is competitive in capturing some aspects of neutrophil motility, but T cell directional persistence only, therein highlighting the importance of evaluating models against several motility metrics simultaneously. This we achieve through novel application of multi-objective optimization, wherein each model is independently implemented and then parameterized to identify optimal trade-offs in performance against each metric. The resultant Pareto

  8. Tropomodulins and tropomyosins - organizers of cellular microcompartments.

    Science.gov (United States)

    Fath, Thomas

    2013-02-01

    Eukaryotic cells show a remarkable compartmentalization into compartments such as the cell nucleus, the Golgi apparatus, the endoplasmic reticulum, and endosomes. However, organelle structures are not the only means by which specialized compartments are formed. Recent research shows a critical role for diverse actin filament populations in defining functional compartments, here referred to as microcompartments, in a wide range of cells. These microcompartments are involved in regulating fundamental cellular functions including cell motility, plasma membrane organization, and cellular morphogenesis. In this overview, the importance of two multigene families of actin-associated proteins, tropomodulins and tropomyosins, their interactions with each other, and a large number of other proteins will be discussed in the context of generating specialized actin-based microcompartments.

  9. High motility reduces grazing mortality of planktonic bacteria

    DEFF Research Database (Denmark)

    Matz, Carsten; Jurgens, K.

    2005-01-01

    We tested the impact of bacterial swimming speed on the survival of planktonic bacteria in the presence of protozoan grazers. Grazing experiments with three common bacterivorous nanoflagellates revealed low clearance rates for highly motile bacteria. High-resolution video microscopy demonstrated...... size revealed highest grazing losses for moderately motile bacteria with a cell size between 0.2 and 0.4 mum(3). Grazing mortality was lowest for cells of >0.5 mum(3) and small, highly motile bacteria. Survival efficiencies of >95% for the ultramicrobacterial isolate CP-1 (less than or equal to0.1 mum......(3), >50 mum s(-1)) illustrated the combined protective action of small cell size and high motility. Our findings suggest that motility has an important adaptive function in the survival of planktonic bacteria during protozoan grazing....

  10. Retinoic acid-induced alveolar cellular growth does not improve function after right pneumonectomy.

    Science.gov (United States)

    Dane, D Merrill; Yan, Xiao; Tamhane, Rahul M; Johnson, Robert L; Estrera, Aaron S; Hogg, Deborah C; Hogg, Richard T; Hsia, Connie C W

    2004-03-01

    To determine whether all-trans retinoic acid (RA) treatment enhances lung function during compensatory lung growth in fully mature animals, adult male dogs (n = 4) received 2 mg x kg(-1) x day(-1) po RA 4 days/wk beginning the day after right pneumonectomy (R-PNX, 55-58% resection). Litter-matched male R-PNX controls (n = 4) received placebo. After 3 mo, transpulmonary pressure (TPP)-lung volume relationship, diffusing capacities for carbon monoxide and nitric oxide, cardiac output, and septal volume (V(tiss-RB)) were measured under anesthesia by a rebreathing technique at two lung volumes. Lung air and tissue volumes (V(air-CT) and V(tiss-CT)) were also measured from high-resolution computerized tomographic (CT) scans at a constant TPP. In RA-treated dogs compared with controls, TPP-lung volume relationships were similar. Diffusing capacities for carbon monoxide and nitric oxide were significantly impaired at a lower lung volume but similar at a high lung volume. Whereas V(tiss-RB) was significantly lower at both lung volumes in RA-treated animals, V(air-CT) and V(tiss-CT) were not different between groups; results suggest uneven distribution of ventilation consistent with distortion of alveolar geometry and/or altered small airway function induced by RA. We conclude that RA does not improve resting pulmonary function during the early months after R-PNX despite histological evidence of its action in enhancing alveolar cellular growth in the remaining lung.

  11. Morpho-functional evaluation of small bowel using wireless motility capsule and video capsule endoscopy in patients with known or suspected Crohn’s disease: pilot study

    OpenAIRE

    Yung, Diana; Douglas, Sarah; Hobson, Anthony; Giannakou, Andry; Plevris, John; Koulaouzidis, Anastasios

    2016-01-01

    BACKGROUND AND STUDY AIMS:SmartPill(®) (Given Imaging Corp.,Yoqneam,Israel) is an ingestible, non-imaging capsule that records physiological data including contractions and pH throughout the gastrointestinal tract. There are scarce data looking at SmartPill(®) assessment of patients with known/suspected small-bowel Crohn's Disease (CD). This pilot study aims to investigate feasibility and safety of SmartPill(®) to assess gut motility in this group. PATIENTS AND METHODS:Over 1 year, patients w...

  12. Elucidating the Function of Penetratin and a Static Magnetic Field in Cellular Uptake of Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    David Stirling

    2013-02-01

    Full Text Available Nanotechnology plays an increasingly important role in the biomedical arena. In particular, magnetic nanoparticles (mNPs have become important tools in molecular diagnostics, in vivo imaging and improved treatment of disease, with the ultimate aim of producing a more theranostic approach. Due to their small sizes, the nanoparticles can cross most of the biological barriers such as the blood vessels and the blood brain barrier, thus providing ubiquitous access to most tissues. In all biomedical applications maximum nanoparticle uptake into cells is required. Two promising methods employed to this end include functionalization of mNPs with cell-penetrating peptides to promote efficient translocation of cargo into the cell and the use of external magnetic fields for enhanced delivery. This study aimed to compare the effect of both penetratin and a static magnetic field with regards to the cellular uptake of 200 nm magnetic NPs and determine the route of uptake by both methods. Results demonstrated that both techniques increased particle uptake, with penetratin proving more cell specific. Clathrin- medicated endocytosis appeared to be responsible for uptake as shown via PCR and western blot, with Pitstop 2 (known to selectively block clathrin formation blocking particle uptake. Interestingly, it was further shown that a magnetic field was able to reverse or overcome the blocking, suggesting an alternative route of uptake.

  13. Cellular and functional specificity among ferritin-like proteins in the multicellular cyanobacterium Nostoc punctiforme.

    Science.gov (United States)

    Ekman, Martin; Sandh, Gustaf; Nenninger, Anja; Oliveira, Paulo; Stensjö, Karin

    2014-03-01

    Ferritin-like proteins constitute a remarkably heterogeneous protein family, including ferritins, bacterioferritins and Dps proteins. The genome of the filamentous heterocyst-forming cyanobacterium Nostoc punctiforme encodes five ferritin-like proteins. In the present paper, we report a multidimensional characterization of these proteins. Our phylogenetic and bioinformatics analyses suggest both structural and physiological differences among the ferritin-like proteins. The expression of these five genes responded differently to hydrogen peroxide treatment, with a significantly higher rise in transcript level for Npun_F3730 as compared with the other four genes. A specific role for Npun_F3730 in the cells tolerance against hydrogen peroxide was also supported by the inactivation of Npun_F3730, Npun_R5701 and Npun_R6212; among these, only the ΔNpun_F3730 strain showed an increased sensitivity to hydrogen peroxide compared with wild type. Analysis of promoter-GFP reporter fusions of the ferritin-like genes indicated that Npun_F3730 and Npun_R5701 were expressed in all cell types of a diazotrophic culture, while Npun_F6212 was expressed specifically in heterocysts. Our study provides the first comprehensive analysis combining functional differentiation and cellular specificity within this important group of proteins in a multicellular cyanobacterium. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  14. Cellular, molecular and functional characterisation of YAC transgenic mouse models of Friedreich ataxia.

    Directory of Open Access Journals (Sweden)

    Sara Anjomani Virmouni

    Full Text Available Friedreich ataxia (FRDA is an autosomal recessive neurodegenerative disorder, caused by a GAA repeat expansion mutation within intron 1 of the FXN gene. We have previously established and performed preliminary characterisation of several human FXN yeast artificial chromosome (YAC transgenic FRDA mouse models containing GAA repeat expansions, Y47R (9 GAA repeats, YG8R (90 and 190 GAA repeats and YG22R (190 GAA repeats.We now report extended cellular, molecular and functional characterisation of these FXN YAC transgenic mouse models. FXN transgene copy number analysis of the FRDA mice demonstrated that the YG22R and Y47R lines each have a single copy of the FXN transgene while the YG8R line has two copies. Single integration sites of all transgenes were confirmed by fluorescence in situ hybridisation (FISH analysis of metaphase and interphase chromosomes. We identified significant functional deficits, together with a degree of glucose intolerance and insulin hypersensitivity, in YG8R and YG22R FRDA mice compared to Y47R and wild-type control mice. We also confirmed increased somatic GAA repeat instability in the cerebellum and brain of YG22R and YG8R mice, together with significantly reduced levels of FXN mRNA and protein in the brain and liver of YG8R and YG22R compared to Y47R.Together these studies provide a detailed characterisation of our GAA repeat expansion-based YAC transgenic FRDA mouse models that will help investigations of FRDA disease mechanisms and therapy.

  15. Cellular Functions of the Autism Risk Factor PTCHD1 in Mice.

    Science.gov (United States)

    Tora, David; Gomez, Andrea M; Michaud, Jean-Francois; Yam, Patricia T; Charron, Frédéric; Scheiffele, Peter

    2017-12-06

    The gene patched domain containing 1 ( PTCHD1 ) is mutated in patients with autism spectrum disorders and intellectual disabilities and has been hypothesized to contribute to Sonic hedgehog (Shh) signaling and synapse formation. We identify a panel of Ptchd1-interacting proteins that include postsynaptic density proteins and the retromer complex, revealing a link to critical regulators of dendritic and postsynaptic trafficking. Ptchd1 knock-out (KO) male mice exhibit cognitive alterations, including defects in a novel object recognition task. To test whether Ptchd1 is required for Shh-dependent signaling, we examined two Shh-dependent cell populations that express high levels of Ptchd1 mRNA: cerebellar granule cell precursors and dentate granule cells in the hippocampus. We found that proliferation of these neuronal precursors was not altered significantly in Ptchd1 KO male mice. We used whole-cell electrophysiology and anatomical methods to assess synaptic function in Ptchd1-deficient dentate granule cells. In the absence of Ptchd1, we observed profound disruption in excitatory/inhibitory balance despite normal dendritic spine density on dentate granule cells. These findings support a critical role of the Ptchd1 protein in the dentate gyrus, but indicate that it is not required for structural synapse formation in dentate granule cells or for Shh-dependent neuronal precursor proliferation. SIGNIFICANCE STATEMENT The mechanisms underlying neuronal and cellular alterations resulting from patched domain containing 1 ( Ptchd1 ) gene mutations are unknown. The results from this study support an association with dendritic trafficking complexes of Ptchd1. Loss-of-function experiments do not support a role in sonic hedgehog-dependent signaling, but reveal a disruption of synaptic transmission in the mouse dentate gyrus. The findings will help to guide ongoing efforts to understand the etiology of neurodevelopmental disorders arising from Ptchd1 deficiency. Copyright

  16. Functional DNA-containing nanomaterials: cellular applications in biosensing, imaging, and targeted therapy.

    Science.gov (United States)

    Liang, Hao; Zhang, Xiao-Bing; Lv, Yifan; Gong, Liang; Wang, Ruowen; Zhu, Xiaoyan; Yang, Ronghua; Tan, Weihong

    2014-06-17

    CONSPECTUS: DNA performs a vital function as a carrier of genetic code, but in the field of nanotechnology, DNA molecules can catalyze chemical reactions in the cell, that is, DNAzymes, or bind with target-specific ligands, that is, aptamers. These functional DNAs with different modifications have been developed for sensing, imaging, and therapeutic systems. Thus, functional DNAs hold great promise for future applications in nanotechnology and bioanalysis. However, these functional DNAs face challenges, especially in the field of biomedicine. For example, functional DNAs typically require the use of cationic transfection reagents to realize cellular uptake. Such reagents enter the cells, increasing the difficulty of performing bioassays in vivo and potentially damaging the cell's nucleus. To address this obstacle, nanomaterials, such as metallic, carbon, silica, or magnetic materials, have been utilized as DNA carriers or assistants. In this Account, we describe selected examples of functional DNA-containing nanomaterials and their applications from our recent research and those of others. As models, we have chosen to highlight DNA/nanomaterial complexes consisting of gold nanoparticles, graphene oxides, and aptamer-micelles, and we illustrate the potential of such complexes in biosensing, imaging, and medical diagnostics. Under proper conditions, multiple ligand-receptor interactions, decreased steric hindrance, and increased surface roughness can be achieved from a high density of DNA that is bound to the surface of nanomaterials, resulting in a higher affinity for complementary DNA and other targets. In addition, this high density of DNA causes a high local salt concentration and negative charge density, which can prevent DNA degradation. For example, DNAzymes assembled on gold nanoparticles can effectively catalyze chemical reactions even in living cells. And it has been confirmed that DNA-nanomaterial complexes can enter cells more easily than free single

  17. Achalasia and Esophageal Motility Disorders

    Science.gov (United States)

    ... Tumors Mediastinal Tumors Achalasia and Esophageal Motility Disorders Pleural Diseases Mesothelioma Achalasia and Esophageal Motility Disorders Overview The esophagus (ĕ-sof´ah-gus) is the hollow, muscular tube that moves food and liquid from your mouth to your stomach. If the ...

  18. Esophageal motility disorders; Motilitaetsstoerungen des Oesophagus

    Energy Technology Data Exchange (ETDEWEB)

    Hannig, C.; Rummeny, E. [Klinikum rechts der Isar der Technischen Universitaet Muenchen, Institut fuer Roentgendiagnostik, Muenchen (Germany); Wuttge-Hannig, A. [Gemeinschaftspraxis fuer Radiologie, Nuklearmedizin und Strahlentherapie, Muenchen (Germany)

    2007-02-15

    For the better understanding of esophageal motility, the muscle texture and the distribution of skeletal and smooth muscle fibers in the esophagus are of crucial importance. Esophageal physiology will be shortly mentioned as far as necessary for a comprehensive understanding of peristaltic disturbances. Besides the pure depiction of morphologic criteria, a complete esophageal study has to include an analysis of the motility. New diagnostic tools with reduced radiation for dynamic imaging (digital fluoroscopy, videofluoroscopy) at 4-30 frames/s are available. Radiomanometry is a combination of a functional pressure measurement and a simultaneous dynamic morphologic analysis. Esophageal motility disorders are subdivided by radiologic and manometric criteria into primary, secondary, and nonclassifiable forms. Primary motility disorders of the esophagus are achalasia, diffuse esophageal spasm, nutcracker esophagus, and the hypertonic lower esophageal sphincter. The secondary motility disorders include pseudoachalasia, reflux-associated motility disorders, functionally caused impactions, Boerhaave's syndrome, Chagas' disease, scleroderma, and presbyesophagus. The nonclassificable motility disorders (NEMD) are a very heterogeneous collective. (orig.) [German] Zum Verstaendnis der Motilitaet des Oesophagus sind muskulaere Architektur und Verteilung der quergestreiften und glatten Muskelfasern von Bedeutung. Die Physiologie des Oesophagus wird in soweit kurz dargestellt, als sie fuer das Verstaendnis von peristaltischen Stoerungen notwendig ist. Neben der Erfassung rein morphologischer Kriterien ist bei der Untersuchung der Speiseroehre eine diagnostische Bewertung der Motilitaet erforderlich. Es stehen uns heute strahlungsarme dynamische Aufzeichnungsverfahren (digitale dynamische Aufzeichnung, Videofluoroskopie) mit Bildsequenzen von 4-30 Bildern/s zur Verfuegung. Die Kombination einer funktionellen Methode zur Darstellung der Morphologie und der

  19. Motility versus fluctuations in mixtures of self-motile and passive agents.

    Science.gov (United States)

    Hinz, Denis F; Panchenko, Alexander; Kim, Tae-Yeon; Fried, Eliot

    2014-12-07

    Many biological systems consist of self-motile and passive agents both of which contribute to overall functionality. However, little is known about the properties of such mixtures. Here we formulate a model for mixtures of self-motile and passive agents and show that the model gives rise to three different dynamical phases: a disordered mesoturbulent phase, a polar flocking phase, and a vortical phase characterized by large-scale counter rotating vortices. We use numerical simulations to construct a phase diagram and compare the statistical properties of the different phases with observed features of self-motile bacterial suspensions. Our findings afford specific insights regarding the interaction of microorganisms and passive particles and provide novel strategic guidance for efficient technological realizations of artificial active matter.

  20. Engineering bacterial motility towards hydrogen-peroxide.

    Science.gov (United States)

    Virgile, Chelsea; Hauk, Pricila; Wu, Hsuan-Chen; Shang, Wu; Tsao, Chen-Yu; Payne, Gregory F; Bentley, William E

    2018-01-01

    Synthetic biologists construct innovative genetic/biological systems to treat environmental, energy, and health problems. Many systems employ rewired cells for non-native product synthesis, while a few have employed the rewired cells as 'smart' devices with programmable function. Building on the latter, we developed a genetic construct to control and direct bacterial motility towards hydrogen peroxide, one of the body's immune response signaling molecules. A motivation for this work is the creation of cells that can target and autonomously treat disease, the latter signaled by hydrogen peroxide release. Bacteria naturally move towards a variety of molecular cues (e.g., nutrients) in the process of chemotaxis. In this work, we engineered bacteria to recognize and move towards hydrogen peroxide, a non-native chemoattractant and potential toxin. Our system exploits oxyRS, the native oxidative stress regulon of E. coli. We first demonstrated H2O2-mediated upregulation motility regulator, CheZ. Using transwell assays, we showed a two-fold increase in net motility towards H2O2. Then, using a 2D cell tracking system, we quantified bacterial motility descriptors including velocity, % running (of tumble/run motions), and a dynamic net directionality towards the molecular cue. In CheZ mutants, we found that increased H2O2 concentration (0-200 μM) and induction time resulted in increased running speeds, ultimately reaching the native E. coli wild-type speed of ~22 μm/s with a ~45-65% ratio of running to tumbling. Finally, using a microfluidic device with stable H2O2 gradients, we characterized responses and the potential for "programmed" directionality towards H2O2 in quiescent fluids. Overall, the synthetic biology framework and tracking analysis in this work will provide a framework for investigating controlled motility of E. coli and other 'smart' probiotics for signal-directed treatment.

  1. Toxicity of cadmium in Japanese quail: Evaluation of body weight, hepatic and renal function, and cellular immune response

    International Nuclear Information System (INIS)

    Sant'Ana, M.G.; Moraes, R.; Bernardi, M.M.

    2005-01-01

    Cadmium (Cd) is an environmental pollutant that is able to alter the immune function. Previous studies have shown that, in mammals, chronic exposure to Cd decreases the release of macrophagic cytokines such as IL1 and TNα and decreases phagocytosis activity. On the other hand contradictory results showed an increase in the humoral response. The cellular response could be decreased by exposure to Cd. These alterations were observed in mammals. The present study aimed to investigate some of the toxic effects of Cd exposure in birds. In particular, the main objective of this work was to elucidate the effects of exposure to this pollutant on the cellular immune function of the Japanese quail as a model for the study of toxicity in animals exposed in nature. The animals were exposed to the metal (100 ppm, per os) during development, i.e., from 1 to 28 days old. Body weight, biochemical parameters, and cellular immune response were measured during and at the end of treatment. The results showed that the exposure to Cd for 28 days significantly reduced the body weight and induced hepatic toxicity. The kidney function and cellular immune response were not affected by the Cd exposure

  2. Using discrete event simulation to change from a functional layout to a cellular layout in an auto parts industry

    Directory of Open Access Journals (Sweden)

    Thiago Buselato Maurício

    2015-07-01

    Full Text Available This paper presents a discrete event simulation employed in a Brazilian automotive company. There was a huge waste caused by one family scrap. It was believed one reason was the company functional layout. In this case, changing from current to cellular layout, employee synergy and knowledge about this family would increase. Due to the complexity for dimensioning a new cellular layout, mainly because of batch size and client’s demand variation. In this case, discrete event simulation was used, which made possible to introduce those effects improving accuracy in final results. This accuracy will be shown by comparing results obtained with simulation and without it (as company used to do. To conclude, cellular layout was responsible for increasing 15% of productivity, reducing lead-time in 7 days and scrap in 15% for this family.

  3. Radiological evaluation of esophageal motility and gastroesophageal reflux disease

    International Nuclear Information System (INIS)

    Schima, W.; Pokieser, P.; Schober, E.

    1995-01-01

    Radiological evaluation of esophageal motility and the lower esophageal sphincter has gained increased attention in recent years. Videofluoroscopic investigation of esophageal motor function is superior to static film radiography, as repeated analysis of the videotaped recordings is possible. With emphasis on radiological techniques, normal esophagel physiology and motility and a variety of esophageal motor disorders are discussed in this review paper. Radiological evaluation of gastroesophageal reflux and reflux esophagitis is described. Clinical and radiological findings in esophageal motility disorders and gastroesophageal reflux disease and the radiological efficacy compared to that of manometry and pH-metry are discussed. (orig.) [de

  4. Glycosaminoglycan-functionalized poly-lactide-co-glycolide nanoparticles: synthesis, characterization, cytocompatibility, and cellular uptake

    Directory of Open Access Journals (Sweden)

    Lamichhane SP

    2015-01-01

    Full Text Available Surya P Lamichhane,1 Neha Arya,1,2 Nirdesh Ojha,3 Esther Kohler,1 V Prasad Shastri1,2,41Institute for Macromolecular Chemistry, University of Freiburg, Freiburg, 2Helmholtz Virtual Institute on “Multifunctional Biomaterials for Medicine”, 3Laboratory for Process Technology, Department of Microsystems Engineering, University of Freiburg, Freiburg, 4Centre for Biological Signaling Studies (BIOSS, University of Freiburg, Freiburg, GermanyAbstract: The efficient delivery of chemotherapeutics to the tumor via nanoparticle (NP-based delivery systems remains a significant challenge. This is compounded by the fact that the tumor is highly dynamic and complex environment composed of a plurality of cell types and extracellular matrix. Since glycosaminoglycan (GAG production is altered in many diseases (or pathologies, NPs bearing GAG moieties on the surface may confer some unique advantages in interrogating the tumor microenvironment. In order to explore this premise, in the study reported here poly-lactide-co-glycolide (PLGA NPs in the range of 100–150 nm bearing various proteoglycans were synthesized by a single-step nanoprecipitation and characterized. The surface functionalization of the NPs with GAG moieties was verified using zeta potential measurements and X-ray photoelectron spectroscopy. To establish these GAG-bearing NPs as carriers of therapeutics, cellular toxicity assays were undertaken in lung epithelial adenocarcinoma (A549 cells, human pulmonary microvascular endothelial cells (HPMEC, and renal proximal tubular epithelial cells. In general NPs were well tolerated over a wide concentration range (100–600 µg/mL by all cell types and were taken up to appreciable extents without any adverse cell response in A549 cells and HPMEC. Further, GAG-functionalized PLGA NPs were taken up to different extents in A459 cells and HPMEC. In both cell systems, the uptake of heparin-modified NPs was diminished by 50%–65% in comparison to that of

  5. The Green Function cellular method and its relation to multiple scattering theory

    International Nuclear Information System (INIS)

    Butler, W.H.; Zhang, X.G.; Gonis, A.

    1992-01-01

    This paper investigates techniques for solving the wave equation which are based on the idea of obtaining exact local solutions within each potential cell, which are then joined to form a global solution. The authors derive full potential multiple scattering theory (MST) from the Lippmann-Schwinger equation and show that it as well as a closely related cellular method are techniques of this type. This cellular method appears to have all of the advantages of MST and the added advantage of having a secular matrix with only nearest neighbor interactions. Since this cellular method is easily linearized one can rigorously reduce electronic structure calculation to the problem of solving a nearest neighbor tight-binding problem

  6. Functionalized graphene oxide/Fe3O4 hybrids for cellular magnetic resonance imaging and fluorescence labeling.

    Science.gov (United States)

    Zhou, Chaohui; Wu, Hui; Wang, Mingliang; Huang, Chusen; Yang, Dapeng; Jia, Nengqin

    2017-09-01

    In this work, we developed a T 2 -weighted contrast agent based on graphene oxide (GO)/Fe 3 O 4 hybrids for efficient cellular magnetic resonance imaging (MRI). The GO/Fe 3 O 4 hybrids were obtained by combining with co-precipitation method and pyrolysis method. The structural, surface and magnetic characteristics of the hybrids were systematically characterized by transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), AFM, Raman, FT-IR and XRD. The GO/Fe 3 O 4 hybrids were functionalized by modifying with anionic and cationic polyelectrolyte through layer-by-layer assembling. The fluorescence probe fluorescein isothiocyanate (FITC) was further loaded on the surface of functionalized GO/Fe 3 O 4 hybrids to trace the location of GO/Fe 3 O 4 hybrids in cells. Functionalized GO/Fe 3 O 4 hybrids possess good hydrophilicity, less cytotoxicity, high MRI enhancement with the relaxivity (r 2 ) of 493mM -1 s -1 as well as cellular MRI contrast effect. These obtained results indicated that the functionalized GO/Fe 3 O 4 hybrids could have great potential to be utilized as cellular MRI contrast agents for tumor early diagnosis and monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Conducting polymer scaffolds for electrical control of cellular functions (Conference Presentation)

    Science.gov (United States)

    Inal, Sahika; Wan, Alwin M.; Williams, Tiffany V.; Giannelis, Emmanuel P.; Fischbach-Teschl, Claudia; Gourdon, Delphine; Owens, Róisín. M.; Malliaras, George G.

    2016-09-01

    Considering the limited physiological relevance of 2D cell culture experiments, significant effort was devoted to the development of materials that could more accurately recreate the in vivo cellular microenvironment, and support 3D cell cultures in vitro. (1) One such class of materials is conducting polymers, which are promising due to their compliant mechanical properties, compatibility with biological systems, mixed electrical and ionic conductivity, and ability to form porous structures. (2) In this work, we report the fabrication of a single component, macroporous scaffold made from poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) via an ice-templating method. (3) PEDOT:PSS scaffolds offer tunable pore size, morphology and shape through facile changes in preparation conditions, and are capable of supporting 3D cell cultures due to their biocompatibility and tissue-like elasticity. Moreover, these materials are functional: they exhibit excellent electrochemical switching behavior and significantly lower impedance compared to films. Their electrochemical activity enables their use in the active channel of a state of the art diagnostic tool in the field of bioelectronics, i.e., the organic electrochemical transistor (OECT). The inclusion of cells within the porous architecture affects the impedance of the electrically-conducting polymer network and, thus, may be used as a method to quantify cell growth. The adhesion and pro-angiogenic secretions of mouse fibroblasts cultured within the scaffolds can be controlled by switching the electrochemical state of the polymer prior to cell-seeding. In summary, these smart materials hold promise not only as extracellular matrix-mimicking structures for cell culture, but also as high-performance bioelectronic tools for diagnostic and signaling applications. References [1] M. Holzwarth, P. X. Ma, Journal of Materials Chemistry, 21, 10243-10251 (2011). [2] L. H. Jimison, J. Rivnay, R. M. Owens, in Organic

  8. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Yan; Hirane, Miku; Araki, Mutsumi [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Fukushima, Nobuyuki [Division of Molecular Neurobiology, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan); Tsujiuchi, Toshifumi, E-mail: ttujiuch@life.kindai.ac.jp [Division of Cancer Biology and Bioinformatics, Department of Life Science, Faculty of Science and Engineering, Kinki University, 3-4-1, Kowakae, Higashiosaka, Osaka 577-8502 (Japan)

    2014-04-04

    Highlights: • LPA{sub 5} inhibits the cell growth and motile activities of 3T3 cells. • LPA{sub 5} suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA{sub 5} on the cell motile activities inhibited by LPA{sub 1} in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA{sub 5} in 3T3 cells. • LPA signaling via LPA{sub 5} acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA{sub 1}–LPA{sub 6}) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA{sub 1} inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA{sub 5} in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA{sub 1} and LPA{sub 5} on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA{sub 5} may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA{sub 1}.

  9. Lysophosphatidic acid receptor-5 negatively regulates cellular responses in mouse fibroblast 3T3 cells

    International Nuclear Information System (INIS)

    Dong, Yan; Hirane, Miku; Araki, Mutsumi; Fukushima, Nobuyuki; Tsujiuchi, Toshifumi

    2014-01-01

    Highlights: • LPA 5 inhibits the cell growth and motile activities of 3T3 cells. • LPA 5 suppresses the cell motile activities stimulated by hydrogen peroxide in 3T3 cells. • Enhancement of LPA 5 on the cell motile activities inhibited by LPA 1 in 3T3 cells. • The expression and activation of Mmp-9 were inhibited by LPA 5 in 3T3 cells. • LPA signaling via LPA 5 acts as a negative regulator of cellular responses in 3T3 cells. - Abstract: Lysophosphatidic acid (LPA) signaling via G protein-coupled LPA receptors (LPA 1 –LPA 6 ) mediates a variety of biological functions, including cell migration. Recently, we have reported that LPA 1 inhibited the cell motile activities of mouse fibroblast 3T3 cells. In the present study, to evaluate a role of LPA 5 in cellular responses, Lpar5 knockdown (3T3-L5) cells were generated from 3T3 cells. In cell proliferation assays, LPA markedly stimulated the cell proliferation activities of 3T3-L5 cells, compared with control cells. In cell motility assays with Cell Culture Inserts, the cell motile activities of 3T3-L5 cells were significantly higher than those of control cells. The activity levels of matrix metalloproteinases (MMPs) were measured by gelatin zymography. 3T3-L5 cells stimulated the activation of Mmp-2, correlating with the expression levels of Mmp-2 gene. Moreover, to assess the co-effects of LPA 1 and LPA 5 on cell motile activities, Lpar5 knockdown (3T3a1-L5) cells were also established from Lpar1 over-expressing (3T3a1) cells. 3T3a1-L5 cells increased the cell motile activities of 3T3a1 cells, while the cell motile activities of 3T3a1 cells were significantly lower than those of control cells. These results suggest that LPA 5 may act as a negative regulator of cellular responses in mouse fibroblast 3T3 cells, similar to the case for LPA 1

  10. Functional Proteomics Defines the Molecular Switch Underlying FGF Receptor Trafficking and Cellular Outputs

    DEFF Research Database (Denmark)

    Francavilla, Chiara; Rigbolt, Kristoffer T.G.; Emdal, Kristina B

    2013-01-01

    The stimulation of fibroblast growth factor receptors (FGFRs) with distinct FGF ligands generates specific cellular responses. However, the mechanisms underlying this paradigm have remained elusive. Here, we show that FGF-7 stimulation leads to FGFR2b degradation and, ultimately, cell proliferation...

  11. Experimental approaches to identify cellular G-quadruplex structures and functions.

    Science.gov (United States)

    Di Antonio, Marco; Rodriguez, Raphaël; Balasubramanian, Shankar

    2012-05-01

    Guanine-rich nucleic acids can fold into non-canonical DNA secondary structures called G-quadruplexes. The formation of these structures can interfere with the biology that is crucial to sustain cellular homeostases and metabolism via mechanisms that include transcription, translation, splicing, telomere maintenance and DNA recombination. Thus, due to their implication in several biological processes and possible role promoting genomic instability, G-quadruplex forming sequences have emerged as potential therapeutic targets. There has been a growing interest in the development of synthetic molecules and biomolecules for sensing G-quadruplex structures in cellular DNA. In this review, we summarise and discuss recent methods developed for cellular imaging of G-quadruplexes, and the application of experimental genomic approaches to detect G-quadruplexes throughout genomic DNA. In particular, we will discuss the use of engineered small molecules and natural proteins to enable pull-down, ChIP-Seq, ChIP-chip and fluorescence imaging of G-quadruplex structures in cellular DNA. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Colonic motility and enema spreading

    International Nuclear Information System (INIS)

    Hardy, J.G.; Wood, E.; Clark, A.G.; Reynolds, J.R.; Queen's Medical Centre, Nottingham

    1986-01-01

    Radiolabelled enema solution was administered to eight healthy subjects, both in fasted and fed states. Enema spreading was monitored over a 4-h period using gamma scintigraphy and colonic motility was recorded simultaneously using a pressure sensitive radiotelemetry capsule. The rate and extent of enema dispersion were unaffected by eating. Spreading could be correlated with colonic motility and was inhibited by aboral propulsion of the colonic contents. (orig.)

  13. Transcriptomic analysis displays the effect of (-)-roemerine on the motility and nutrient uptake in Escherichia coli.

    Science.gov (United States)

    Ayyildiz, Dilara; Arga, Kazim Yalcin; Avci, Fatma Gizem; Altinisik, Fatma Ece; Gurer, Caglayan; Gulsoy Toplan, Gizem; Kazan, Dilek; Wozny, Katharina; Brügger, Britta; Mertoglu, Bulent; Sariyar Akbulut, Berna

    2017-08-01

    Among the different families of plant alkaloids, (-)-roemerine, an aporphine type, was recently shown to possess significant antibacterial activity in Escherichia coli. Based on the increasing demand for antibacterials with novel mechanisms of action, the present work investigates the potential of the plant-derived alkaloid (-)-roemerine as an antibacterial in E. coli cells using microarray technology. Analysis of the genome-wide transcriptional reprogramming in cells after 60 min treatment with 100 μg/mL (-)-roemerine showed significant changes in the expression of 241 genes (p value 2). Expression of selected genes was confirmed by qPCR. Differentially expressed genes were classified into functional categories to map biological processes and molecular pathways involved. Cellular activities with roles in carbohydrate transport and metabolism, energy production and conversion, lipid transport and metabolism, amino acid transport and metabolism, two-component signaling systems, and cell motility (in particular, the flagellar organization and motility) were among metabolic processes altered in the presence of (-)-roemerine. The down-regulation of the outer membrane proteins probably led to a decrease in carbohydrate uptake rate, which in turn results in nutrient limitation. Consequently, energy metabolism is slowed down. Interestingly, the majority of the expressional alterations were found in the flagellar system. This suggested reduction in motility and loss in the ability to form biofilms, thus affecting protection of E. coli against host cell defense mechanisms. In summary, our findings suggest that the antimicrobial action of (-)-roemerine in E. coli is linked to disturbances in motility and nutrient uptake.

  14. Effect of total laryngectomy on esophageal motility

    International Nuclear Information System (INIS)

    Hanks, J.B.; Fisher, S.R.; Meyers, W.C.; Christian, K.C.; Postlethwait, R.W.; Jones, R.S.

    1981-01-01

    Total laryngectomy for cancer can result in dysphagia and altered esophageal motility. Manometric changes in the upper esophageal sphincter (UES), and in proximal and distal esophageal function have been reported. However, most studies have failed to take into account radiation therapy and appropriate controls. We selected ten male patients (54.3 +/- 1.9 yr) for longitudinal manometric evaluation prior to laryngectomy then at two weeks and again six months later. No patient received preoperative radiation therapy, had a previous history of esophageal surgery, or developed a postoperative wound infection or fistula. Seven of ten patients had positive nodes and received 6,000-6,600 rads postoperative radiation therapy. Preoperatively 4 of 10 patients complained of dysphagia which did not significantly change following surgery and radiation. Two of three patients who did not complain of dysphagia preoperatively and received radiation postoperatively developed dysphagia. No patient without dysphagia preoperatively who received no radiation therapy developed symptoms. Our studies show that laryngectomy causes alterations in the UES resting and peak pressures but not in the proximal or distal esophagus, or the lower esophageal sphincter. These data also imply radiation therapy may be associated with progressive alterations in motility and symptomatology. Further study regarding the effects of radiation on esophageal motility and function are urged

  15. Aging and intestinal motility: a review of factors that affect intestinal motility in the aged.

    LENUS (Irish Health Repository)

    O'Mahony, Denis

    2012-02-03

    Normal aging is associated with significant changes in the function of most organs and tissues. In this regard, the gastrointestinal tract is no exception. The purpose of this review is to detail the important age-related changes in motor function of the various parts of the gastrointestinal tract and to highlight some of the important motility changes that may occur, either in relation to common age-related disorders, or as a result of certain drugs commonly prescribed in the aged. A major confounding factor in the interpretation of motor phenomena throughout the gastrointestinal tract in this age group is the frequent coexistence of neurological, endocrinological and other disease states, which may be independently associated with dysmotility. Overall, current data are insufficient to implicate normal aging as a cause of dysmotility in the elderly. Normal aging is associated with various changes in gastrointestinal motility, but the clinical significance of such changes remains unclear. More important is the impact of various age-related diseases on gastrointestinal motility in the elderly: for example, long-standing diabetes mellitus may reduce gastric emptying in up to 50% of patients; depression significantly prolongs whole-gut transit time; hypothyroidism may prolong oro-caecal transit time; and chronic renal failure is associated with impaired gastric emptying. In addition, various, frequently used drugs in the elderly cause disordered gastrointestinal motility. These drugs include anticholinergics, especially antidepressants with an anticholinergic effect, opioid analgesics and calcium antagonists.

  16. Structure and function of mammalian cilia

    DEFF Research Database (Denmark)

    Satir, Peter; Christensen, Søren T

    2008-01-01

    In the past half century, beginning with electron microscopic studies of 9 + 2 motile and 9 + 0 primary cilia, novel insights have been obtained regarding the structure and function of mammalian cilia. All cilia can now be viewed as sensory cellular antennae that coordinate a large number...

  17. Interactions among motility, fertilizing ability, and testosterone binding on spermatozoa of bonnet monkey (Macaca radiata).

    Science.gov (United States)

    Warikoo, P K; Majumdar, S S; Allag, I S; Das, R P; Roy, S

    1986-01-01

    Fresh ejaculates of bonnet monkeys were separated into fractions rich with highly motile and sluggishly motile spermatozoa. The motility, ability to fertilize zona-free hamster eggs, and distribution of testosterone-binding sites on spermatozoa were assessed to determine the relation between these sperm functions. Two parameters of objective assessment of motility--velocity and degree of flagellar bending--were significantly correlated with the ability to form pronuclei in zona-free hamster eggs. Only spermatozoa with good motility could form pronuclei, which might be important for assessment of the fertilizing ability. The motility was directly related to the distribution of testosterone-binding sites; the fraction having mostly motile spermatozoa was distributed over the sperm surface. The technique is simple and may be used to evaluate semen of nonhuman primates.

  18. Parasites in motion: flagellum-driven cell motility in African trypanosomes

    Science.gov (United States)

    Hill, Kent L.

    2011-01-01

    SUMMARY Motility of the sleeping sickness parasite, Trypanosoma brucei, impacts disease transmission and pathogenesis. Trypanosome motility is driven by a flagellum that harbors a canonical 9 + 2 axoneme, together with trypanosome-specific elaborations. Trypanosome flagellum biology and motility have been the object of intense research over the last two years. These studies have led to the discovery of a novel form of motility, termed social motility, and provided revision of long-standing models for cell propulsion. Recent work has also uncovered novel structural features and motor proteins associated with the flagellar apparatus and has identified candidate signaling molecules that are predicted to regulate flagellar motility. Together with earlier inventories of flagellar proteins from proteomic and genomic studies, the stage is now set to move forward with functional studies to elucidate molecular mechanisms and investigate parasite motility in the context of host-parasite interactions. PMID:20591724

  19. Rac and Rho GTPases in cancer cell motility control

    Directory of Open Access Journals (Sweden)

    Parri Matteo

    2010-09-01

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

  20. Functional and genetic deconstruction of the cellular origin in liver cancer

    DEFF Research Database (Denmark)

    Marquardt, Jens U; Andersen, Jesper B; Thorgeirsson, Snorri S

    2015-01-01

    During the past decade, research on primary liver cancers has particularly highlighted the uncommon plasticity of differentiated parenchymal liver cells (that is, hepatocytes and cholangiocytes (also known as biliary epithelial cells)), the role of liver progenitor cells in malignant transformation......, the importance of the tumour microenvironment and the molecular complexity of liver tumours. Whereas other reviews have focused on the landscape of genetic alterations that promote development and progression of primary liver cancers and the role of the tumour microenvironment, the crucial importance...... of the cellular origin of liver cancer has been much less explored. Therefore, in this Review, we emphasize the importance and complexity of the cellular origin in tumour initiation and progression, and attempt to integrate this aspect with recent discoveries in tumour genomics and the contribution...

  1. Active motility in bimodular bacterial aggregates

    Science.gov (United States)

    Zeng, Yu; Liu, Bin

    2017-11-01

    Dispersal capability is essential for microorganisms to achieve long-distance translocation, thus crucial for their abundance in various environments. In general, active dispersals are attributed to the movements of self-powered planktonic cells, while sessile cells that live a colonial life often disperse passively through flow entrainments. Here, we report another means of active dispersal employed by aggregates of sessile cells. The spherical rosette colonies of the bacterium Caulobacter crescentus are aggregates of sessile stalked cells, of which a small proportion undergo cell division, grow active flagella and effect whole-rosette motility. We show that these rosettes actively disperse both in bulk water and near the solid-liquid interface. In particular, the proximity of a self-powered rosette to the solid surface promotes a rolling movement, leading to its persistent transportation along the solid boundary. The active dispersal of these rosettes demonstrated a novel mode of colonial transportation that is based on the division of labor between sessile and motile cells. The authors thank the support of National Science Foundation CREST: Center for Cellular and Biomolecular Machines at UC Merced (NSF-HRD-1547848).

  2. Analyses of Dynein Heavy Chain Mutations Reveal Complex Interactions Between Dynein Motor Domains and Cellular Dynein Functions

    Science.gov (United States)

    Sivagurunathan, Senthilkumar; Schnittker, Robert R.; Razafsky, David S.; Nandini, Swaran; Plamann, Michael D.; King, Stephen J.

    2012-01-01

    Cytoplasmic dynein transports cargoes for a variety of crucial cellular functions. However, since dynein is essential in most eukaryotic organisms, the in-depth study of the cellular function of dynein via genetic analysis of dynein mutations has not been practical. Here, we identify and characterize 34 different dynein heavy chain mutations using a genetic screen of the ascomycete fungus Neurospora crassa, in which dynein is nonessential. Interestingly, our studies show that these mutations segregate into five different classes based on the in vivo localization of the mutated dynein motors. Furthermore, we have determined that the different classes of dynein mutations alter vesicle trafficking, microtubule organization, and nuclear distribution in distinct ways and require dynactin to different extents. In addition, biochemical analyses of dynein from one mutant strain show a strong correlation between its in vitro biochemical properties and the aberrant intracellular function of that altered dynein. When the mutations were mapped to the published dynein crystal structure, we found that the three-dimensional structural locations of the heavy chain mutations were linked to particular classes of altered dynein functions observed in cells. Together, our data indicate that the five classes of dynein mutations represent the entrapment of dynein at five separate points in the dynein mechanochemical and transport cycles. We have developed N. crassa as a model system where we can dissect the complexities of dynein structure, function, and interaction with other proteins with genetic, biochemical, and cell biological studies. PMID:22649085

  3. Lysine acetylation targets protein complexes and co-regulates major cellular functions

    DEFF Research Database (Denmark)

    Choudhary, Chuna Ram; Kumar, Chanchal; Gnad, Florian

    2009-01-01

    Lysine acetylation is a reversible posttranslational modification of proteins and plays a key role in regulating gene expression. Technological limitations have so far prevented a global analysis of lysine acetylation's cellular roles. We used high-resolution mass spectrometry to identify 3600......, cell cycle, splicing, nuclear transport, and actin nucleation. Acetylation impaired phosphorylation-dependent interactions of 14-3-3 and regulated the yeast cyclin-dependent kinase Cdc28. Our data demonstrate that the regulatory scope of lysine acetylation is broad and comparable with that of other...

  4. Disruption of Hox9,10,11 function results in cellular level lineage infidelity in the kidney.

    Science.gov (United States)

    Drake, Keri A; Adam, Mike; Mahoney, Robert; Potter, S Steven

    2018-04-20

    Hox genes are important regulators of development. The 39 mammalian Hox genes have considerable functional overlap, greatly confounding their study. In this report, we generated mice with multiple combinations of paralogous and flanking Abd-B Hox gene mutations to investigate functional redundancies in kidney development. The resulting mice developed a number of kidney abnormalities, including hypoplasia, agenesis, and severe cysts, with distinct Hox functions observed in early metanephric kidney formation and nephron progenitor maintenance. Most surprising, however, was that extensive removal of Hox shared function in these kidneys resulted in cellular level lineage infidelity. Strikingly, mutant nephron tubules consisted of intermixed cells with proximal tubule, loop of Henle, and collecting duct identities, with some single cells expressing markers associated with more than one nephron segment. These results indicate that Hox genes are required for proper lineage selection/maintenance and full repression of genes involved in cell fate restriction in the developing kidney.

  5. Picornaviruses and nuclear functions: targeting a cellular compartment distinct from the replication site of a positive-strand RNA virus

    Directory of Open Access Journals (Sweden)

    Dylan eFlather

    2015-06-01

    Full Text Available The compartmentalization of DNA replication and gene transcription in the nucleus and protein production in the cytoplasm is a defining feature of eukaryotic cells. The nucleus functions to maintain the integrity of the nuclear genome of the cell and to control gene expression based on intracellular and environmental signals received through the cytoplasm. The spatial separation of the major processes that lead to the expression of protein-coding genes establishes the necessity of a transport network to allow biomolecules to translocate between these two regions of the cell. The nucleocytoplasmic transport network is therefore essential for regulating normal cellular functioning. The Picornaviridae virus family is one of many viral families that disrupt the nucleocytoplasmic trafficking of cells to promote viral replication. Picornaviruses contain positive-sense, single-stranded RNA genomes and replicate in the cytoplasm of infected cells. As a result of the limited coding capacity of these viruses, cellular proteins are required by these intracellular parasites for both translation and genomic RNA replication. Being of messenger RNA polarity, a picornavirus genome can immediately be translated upon entering the cell cytoplasm. However, the replication of viral RNA requires the activity of RNA-binding proteins, many of which function in host gene expression, and are consequently localized to the nucleus. As a result, picornaviruses disrupt nucleocytoplasmic trafficking to exploit protein functions normally localized to a different cellular compartment from which they translate their genome to facilitate efficient replication. Furthermore, picornavirus proteins are also known to enter the nucleus of infected cells to limit host-cell transcription and down-regulate innate antiviral responses. The interactions of picornavirus proteins and host-cell nuclei are extensive, required for a productive infection, and are the focus of this review.

  6. Robust Template Decomposition without Weight Restriction for Cellular Neural Networks Implementing Arbitrary Boolean Functions Using Support Vector Classifiers

    Directory of Open Access Journals (Sweden)

    Yih-Lon Lin

    2013-01-01

    Full Text Available If the given Boolean function is linearly separable, a robust uncoupled cellular neural network can be designed as a maximal margin classifier. On the other hand, if the given Boolean function is linearly separable but has a small geometric margin or it is not linearly separable, a popular approach is to find a sequence of robust uncoupled cellular neural networks implementing the given Boolean function. In the past research works using this approach, the control template parameters and thresholds are restricted to assume only a given finite set of integers, and this is certainly unnecessary for the template design. In this study, we try to remove this restriction. Minterm- and maxterm-based decomposition algorithms utilizing the soft margin and maximal margin support vector classifiers are proposed to design a sequence of robust templates implementing an arbitrary Boolean function. Several illustrative examples are simulated to demonstrate the efficiency of the proposed method by comparing our results with those produced by other decomposition methods with restricted weights.

  7. Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy

    Science.gov (United States)

    Misra, Santosh K.; Mukherjee, Prabuddha; Chang, Huei-Huei; Tiwari, Saumya; Gryka, Mark; Bhargava, Rohit; Pan, Dipanjan

    2016-07-01

    Typically, multiplexing high nanoparticle uptake, imaging, and therapy requires careful integration of three different functions of a multiscale molecular-particle assembly. Here, we present a simpler approach to multiplexing by utilizing one component of the system for multiple functions. Specifically, we successfully synthesized and characterized colloidal carotene carbon nanoparticle (C3-NP), in which a single functional molecule served a threefold purpose. First, the presence of carotene moieties promoted the passage of the particle through the cell membrane and into the cells. Second, the ligand acted as a potent detrimental moiety for cancer cells and, finally, the ligands produced optical contrast for robust microscopic detection in complex cellular environments. In comparative tests, C3-NP were found to provide effective intracellular delivery that enables both robust detection at cellular and tissue level and presents significant therapeutic potential without altering the mechanism of intracellular action of β-carotene. Surface coating of C3 with phospholipid was used to generate C3-Lipocoat nanoparticles with further improved function and biocompatibility, paving the path to eventual in vivo studies.

  8. Structural requirements for the assembly of LINC complexes and their function in cellular mechanical stiffness

    International Nuclear Information System (INIS)

    Stewart-Hutchinson, P.J.; Hale, Christopher M.; Wirtz, Denis; Hodzic, Didier

    2008-01-01

    The evolutionary-conserved interactions between KASH and SUN domain-containing proteins within the perinuclear space establish physical connections, called LINC complexes, between the nucleus and the cytoskeleton. Here, we show that the KASH domains of Nesprins 1, 2 and 3 interact promiscuously with luminal domains of Sun1 and Sun2. These constructs disrupt endogenous LINC complexes as indicated by the displacement of endogenous Nesprins from the nuclear envelope. We also provide evidence that KASH domains most probably fit a pocket provided by SUN domains and that post-translational modifications are dispensable for that interaction. We demonstrate that the disruption of endogenous LINC complexes affect cellular mechanical stiffness to an extent that compares to the loss of mechanical stiffness previously reported in embryonic fibroblasts derived from mouse lacking A-type lamins, a mouse model of muscular dystrophies and cardiomyopathies. These findings support a model whereby physical connections between the nucleus and the cytoskeleton are mediated by interactions between diverse combinations of Sun proteins and Nesprins through their respective evolutionary-conserved domains. Furthermore, they emphasize, for the first time, the relevance of LINC complexes in cellular mechanical stiffness suggesting a possible involvement of their disruption in various laminopathies, a group of human diseases linked to mutations of A-type lamins

  9. Motility of electric cable bacteria

    DEFF Research Database (Denmark)

    Bjerg, Jesper Tataru; Damgaard, Lars Riis; Holm, Simon Agner

    2016-01-01

    Cable bacteria are filamentous bacteria that electrically couple sulfide oxidation and oxygen reduction at centimeter distances, and observations in sediment environments have suggested that they are motile. By time-lapse microscopy, we found that cable bacteria used gliding motility on surfaces...... with a highly variable speed of 0.50.3 ms1 (meanstandard deviation) and time between reversals of 155108 s. They frequently moved forward in loops, and formation of twisted loops revealed helical rotation of the filaments. Cable bacteria responded to chemical gradients in their environment, and around the oxic......-anoxic interface, they curled and piled up, with straight parts connecting back to the source of sulfide. Thus, it appears that motility serves the cable bacteria in establishing and keeping optimal connections between their distant electron donor and acceptors in a dynamic sediment environment....

  10. Stochastic models of cell motility

    DEFF Research Database (Denmark)

    Gradinaru, Cristian

    2012-01-01

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

  11. Dimer monomer transition and dimer re-formation play important role for ATM cellular function during DNA repair

    International Nuclear Information System (INIS)

    Du, Fengxia; Zhang, Minjie; Li, Xiaohua; Yang, Caiyun; Meng, Hao; Wang, Dong; Chang, Shuang; Xu, Ye; Price, Brendan; Sun, Yingli

    2014-01-01

    Highlights: • ATM phosphorylates the opposite strand of the dimer in response to DNA damage. • The PETPVFRLT box of ATM plays a key role in its dimer dissociation in DNA repair. • The dephosphorylation of ATM is critical for dimer re-formation after DNA repair. - Abstract: The ATM protein kinase, is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks, mediates responses to ionizing radiation in mammalian cells. Here we show that ATM is held inactive in unirradiated cells as a dimer and phosphorylates the opposite strand of the dimer in response to DNA damage. Cellular irradiation induces rapid intermolecular autophosphorylation of serine 1981 that causes dimer dissociation and initiates cellular ATM kinase activity. ATM cannot phosphorylate the substrates when it could not undergo dimer monomer transition. After DNA repair, the active monomer will undergo dephosphorylation to form dimer again and dephosphorylation is critical for dimer re-formation. Our work reveals novel function of ATM dimer monomer transition and explains why ATM dimer monomer transition plays such important role for ATM cellular activity during DNA repair

  12. Cellular metabolism

    International Nuclear Information System (INIS)

    Hildebrand, C.E.; Walters, R.A.

    1977-01-01

    Progress is reported on the following research projects: chromatin structure; the use of circular synthetic polydeoxynucleotides as substrates for the study of DNA repair enzymes; human cellular kinetic response following exposure to DNA-interactive compounds; histone phosphorylation and chromatin structure in cell proliferation; photoaddition products induced in chromatin by uv light; pollutants and genetic information transfer; altered RNA metabolism as a function of cadmium accumulation and intracellular distribution in cultured cells; and thymidylate chromophore destruction by water free radicals

  13. Actin dynamics, architecture, and mechanics in cell motility.

    Science.gov (United States)

    Blanchoin, Laurent; Boujemaa-Paterski, Rajaa; Sykes, Cécile; Plastino, Julie

    2014-01-01

    Tight coupling between biochemical and mechanical properties of the actin cytoskeleton drives a large range of cellular processes including polarity establishment, morphogenesis, and motility. This is possible because actin filaments are semi-flexible polymers that, in conjunction with the molecular motor myosin, can act as biological active springs or "dashpots" (in laymen's terms, shock absorbers or fluidizers) able to exert or resist against force in a cellular environment. To modulate their mechanical properties, actin filaments can organize into a variety of architectures generating a diversity of cellular organizations including branched or crosslinked networks in the lamellipodium, parallel bundles in filopodia, and antiparallel structures in contractile fibers. In this review we describe the feedback loop between biochemical and mechanical properties of actin organization at the molecular level in vitro, then we integrate this knowledge into our current understanding of cellular actin organization and its physiological roles.

  14. Social motility in african trypanosomes.

    Directory of Open Access Journals (Sweden)

    Michael Oberholzer

    2010-01-01

    Full Text Available African trypanosomes are devastating human and animal pathogens that cause significant human mortality and limit economic development in sub-Saharan Africa. Studies of trypanosome biology generally consider these protozoan parasites as individual cells in suspension cultures or in animal models of infection. Here we report that the procyclic form of the African trypanosome Trypanosoma brucei engages in social behavior when cultivated on semisolid agarose surfaces. This behavior is characterized by trypanosomes assembling into multicellular communities that engage in polarized migrations across the agarose surface and cooperate to divert their movements in response to external signals. These cooperative movements are flagellum-mediated, since they do not occur in trypanin knockdown parasites that lack normal flagellum motility. We term this behavior social motility based on features shared with social motility and other types of surface-induced social behavior in bacteria. Social motility represents a novel and unexpected aspect of trypanosome biology and offers new paradigms for considering host-parasite interactions.

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

    Science.gov (United States)

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

    2016-01-01

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

  16. Curriculum for neurogastroenterology and motility training

    DEFF Research Database (Denmark)

    Gyawali, C P; Savarino, E; Lazarescu, A

    2018-01-01

    Although neurogastroenterology and motility (NGM) disorders are some of the most frequent disorders encountered by practicing gastroenterologists, a structured competency-based training curriculum developed by NGM experts is lacking. The American Neurogastroenterology and Motility Society (ANMS) ...

  17. Adhesion GPCRs CD97 and GPR56: From structural regulation to cellular function

    NARCIS (Netherlands)

    Hsiao, C.-C.

    2015-01-01

    Cells correspond with their environment through receptors that translate extracellular signals into intracellular messages. Members of the large superfamily of G protein-coupled receptors (GPCRs) control various physiological functions and have been implicated in numerous diseases. Adhesion GPCRs

  18. Primary Esophageal Motility Disorders: Beyond Achalasia

    OpenAIRE

    Schlottmann, Francisco; Patti, Marco G.

    2017-01-01

    The best-defined primary esophageal motor disorder is achalasia. However, symptoms such as dysphagia, regurgitation and chest pain can be caused by other esophageal motility disorders. The Chicago classification introduced new manometric parameters and better defined esophageal motility disorders. Motility disorders beyond achalasia with the current classification are: esophagogastric junction outflow obstruction, major disorders of peristalsis (distal esophageal spasm, hypercontractile esoph...

  19. Cellular and molecular basis of chronic constipation: taking the functional/idiopathic label out.

    Science.gov (United States)

    Bassotti, Gabrio; Villanacci, Vincenzo; Creţoiu, Dragos; Creţoiu, Sanda Maria; Becheanu, Gabriel

    2013-07-14

    In recent years, the improvement of technology and the increase in knowledge have shifted several strongly held paradigms. This is particularly true in gastroenterology, and specifically in the field of the so-called "functional" or "idiopathic" disease, where conditions thought for decades to be based mainly on alterations of visceral perception or aberrant psychosomatic mechanisms have, in fact, be reconducted to an organic basis (or, at the very least, have shown one or more demonstrable abnormalities). This is particularly true, for instance, for irritable bowel syndrome, the prototype entity of "functional" gastrointestinal disorders, where low-grade inflammation of both mucosa and myenteric plexus has been repeatedly demonstrated. Thus, researchers have also investigated other functional/idiopathic gastrointestinal disorders, and found that some organic ground is present, such as abnormal neurotransmission and myenteric plexitis in esophageal achalasia and mucosal immune activation and mild eosinophilia in functional dyspepsia. Here we show evidence, based on our own and other authors' work, that chronic constipation has several abnormalities reconductable to alterations in the enteric nervous system, abnormalities mainly characterized by a constant decrease of enteric glial cells and interstitial cells of Cajal (and, sometimes, of enteric neurons). Thus, we feel that (at least some forms of) chronic constipation should no more be considered as a functional/idiopathic gastrointestinal disorder, but instead as a true enteric neuropathic abnormality.

  20. Complement factor H family proteins in their non-canonical role as modulators of cellular functions.

    Science.gov (United States)

    Józsi, Mihály; Schneider, Andrea E; Kárpáti, Éva; Sándor, Noémi

    2018-01-04

    Complement factor H is a major regulator of the alternative pathway of the complement system. The factor H-related proteins are less characterized, but recent data indicate that they rather promote complement activation. These proteins have some common ligands with factor H and have both overlapping and distinct functions depending on domain composition and the degree of conservation of amino acid sequence. Factor H and some of the factor H-related proteins also appear in a non-canonical function that is beyond their role in the modulation of complement activation. This review covers our current understanding on this emerging role of factor H family proteins in modulating the activation and function of various cells by binding to receptors or receptor ligands. Copyright © 2018 Elsevier Ltd. All rights reserved.

  1. Intermediate Filaments as Organizers of Cellular Space: How They Affect Mitochondrial Structure and Function.

    Science.gov (United States)

    Schwarz, Nicole; Leube, Rudolf E

    2016-07-05

    Intermediate filaments together with actin filaments and microtubules form the cytoskeleton, which is a complex and highly dynamic 3D network. Intermediate filaments are the major mechanical stress protectors but also affect cell growth, differentiation, signal transduction, and migration. Using intermediate filament-mitochondrial crosstalk as a prominent example, this review emphasizes the importance of intermediate filaments as crucial organizers of cytoplasmic space to support these functions. We summarize observations in different mammalian cell types which demonstrate how intermediate filaments influence mitochondrial morphology, subcellular localization, and function through direct and indirect interactions and how perturbations of these interactions may lead to human diseases.

  2. Neutrophil degranulation and immunosuppression in patients with GBM: restoration of cellular immune function by targeting arginase I.

    Science.gov (United States)

    Sippel, Trisha R; White, Jason; Nag, Kamalika; Tsvankin, Vadim; Klaassen, Marci; Kleinschmidt-DeMasters, B K; Waziri, Allen

    2011-11-15

    The source of glioblastoma (GBM)-associated immunosuppression remains multifactorial. We sought to clarify and therapeutically target myeloid cell-derived peripheral immunosuppression in patients with GBM. Direct ex vivo T-cell function, serum Arginase I (ArgI) levels, and circulating myeloid lineage populations were compared between patients with GBM and normal donors or patients with other intracranial tumors. Immunofunctional assays were conducted using bulk and sorted cell populations to explore the potential transfer of myeloid cell-mediated immunosuppression and to identify a potential mechanism for these effects. ArgI-mediated immunosuppression was therapeutically targeted in vitro through pharmacologic inhibition or arginine supplementation. We identified a significantly expanded population of circulating, degranulated neutrophils associated with elevated levels of serum ArgI and decreased T-cell CD3ζ expression within peripheral blood from patients with GBM. Sorted CD11b(+) cells from patients with GBM were found to markedly suppress normal donor T-cell function in coculture, and media harvested from mitogen-stimulated GBM peripheral blood mononuclear cell (PBMC) or GBM-associated mixed lymphoid reactions showed ArgI levels that were significantly higher than controls. Critically, T-cell suppression in both settings could be completely reversed through pharmacologic ArgI inhibition or with arginine supplementation. These data indicate that peripheral cellular immunosuppression in patients with GBM is associated with neutrophil degranulation and elevated levels of circulating ArgI, and that T-cell function can be restored in these individuals by targeting ArgI. These data identify a novel pathway of GBM-mediated suppression of cellular immunity and offer a potential therapeutic window for improving antitumor immunity in affected patients.

  3. Primary Esophageal Motility Disorders: Beyond Achalasia.

    Science.gov (United States)

    Schlottmann, Francisco; Patti, Marco G

    2017-06-30

    The best-defined primary esophageal motor disorder is achalasia. However, symptoms such as dysphagia, regurgitation and chest pain can be caused by other esophageal motility disorders. The Chicago classification introduced new manometric parameters and better defined esophageal motility disorders. Motility disorders beyond achalasia with the current classification are: esophagogastric junction outflow obstruction, major disorders of peristalsis (distal esophageal spasm, hypercontractile esophagus, absent contractility) and minor disorders of peristalsis (ineffective esophageal motility, fragmented peristalsis). The aim of this study was to review the current diagnosis and management of esophageal motility disorders other than achalasia.

  4. Measuring Borrelia burgdorferi Motility and Chemotaxis.

    Science.gov (United States)

    Zhang, Kai; Li, Chunhao

    2018-01-01

    Swimming plate, cell motion tracking, and capillary tube assays are very useful tools to quantitatively measure bacterial motility and chemotaxis. These methods were modified and applied to study Borrelia burgdorferi motility and chemotaxis. By using these methods, numerous motility and chemotaxis mutants have been characterized and several chemoattractants were identified. With the assistance of these tools, the role of motility and chemotaxis in the pathogenicity of B. burgdorferi has been established. In addition, these tools also facilitate the study of motility and chemotaxis in other spirochetes.

  5. Recycling of inorganic waste in monolithic and cellular glass-based materials for structural and functional applications.

    Science.gov (United States)

    Rincón, Acacio; Marangoni, Mauro; Cetin, Suna; Bernardo, Enrico

    2016-07-01

    The stabilization of inorganic waste of various nature and origin, in glasses, has been a key strategy for environmental protection for the last decades. When properly formulated, glasses may retain many inorganic contaminants permanently, but it must be acknowledged that some criticism remains, mainly concerning costs and energy use. As a consequence, the sustainability of vitrification largely relies on the conversion of waste glasses into new, usable and marketable glass-based materials, in the form of monolithic and cellular glass-ceramics. The effective conversion in turn depends on the simultaneous control of both starting materials and manufacturing processes. While silica-rich waste favours the obtainment of glass, iron-rich wastes affect the functionalities, influencing the porosity in cellular glass-based materials as well as catalytic, magnetic, optical and electrical properties. Engineered formulations may lead to important reductions of processing times and temperatures, in the transformation of waste-derived glasses into glass-ceramics, or even bring interesting shortcuts. Direct sintering of wastes, combined with recycled glasses, as an example, has been proven as a valid low-cost alternative for glass-ceramic manufacturing, for wastes with limited hazardousness. The present paper is aimed at providing an up-to-date overview of the correlation between formulations, manufacturing technologies and properties of most recent waste-derived, glass-based materials. © 2016 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

  6. Recycling of inorganic waste in monolithic and cellular glass‐based materials for structural and functional applications

    Science.gov (United States)

    Rincón, Acacio; Marangoni, Mauro; Cetin, Suna

    2016-01-01

    Abstract The stabilization of inorganic waste of various nature and origin, in glasses, has been a key strategy for environmental protection for the last decades. When properly formulated, glasses may retain many inorganic contaminants permanently, but it must be acknowledged that some criticism remains, mainly concerning costs and energy use. As a consequence, the sustainability of vitrification largely relies on the conversion of waste glasses into new, usable and marketable glass‐based materials, in the form of monolithic and cellular glass‐ceramics. The effective conversion in turn depends on the simultaneous control of both starting materials and manufacturing processes. While silica‐rich waste favours the obtainment of glass, iron‐rich wastes affect the functionalities, influencing the porosity in cellular glass‐based materials as well as catalytic, magnetic, optical and electrical properties. Engineered formulations may lead to important reductions of processing times and temperatures, in the transformation of waste‐derived glasses into glass‐ceramics, or even bring interesting shortcuts. Direct sintering of wastes, combined with recycled glasses, as an example, has been proven as a valid low‐cost alternative for glass‐ceramic manufacturing, for wastes with limited hazardousness. The present paper is aimed at providing an up‐to‐date overview of the correlation between formulations, manufacturing technologies and properties of most recent waste‐derived, glass‐based materials. © 2016 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:27818564

  7. Poly(methyl vinyl ether-alt-maleic acid)-functionalized porous silicon nanoparticles for enhanced stability and cellular internalization.

    Science.gov (United States)

    Shahbazi, Mohammad-Ali; Almeida, Patrick V; Mäkilä, Ermei; Correia, Alexandra; Ferreira, Mónica P A; Kaasalainen, Martti; Salonen, Jarno; Hirvonen, Jouni; Santos, Hélder A

    2014-03-01

    Currently, developing a stable nanocarrier with high cellular internalization and low toxicity is a key bottleneck in nanomedicine. Here, we have developed a successful method to covalently conjugate poly(methyl vinyl ether-co-maleic acid) (PMVE-MA) copolymer on the surface of (3-aminopropyl)triethoxysilane-functionalized thermally carbonized porous silicon nanoparticles (APSTCPSi NPs), forming a surface negatively charged nanovehicle with unique properties. This polymer conjugated NPs could modify surface smoothness, charge, and hydrophilicity of the developed NPs, leading to considerable improvement in the colloidal and plasma stabilities via enhanced suspensibility and charge repulsion. Furthermore, despite the surface negative charge of the polymer-conjugated NPs, the cellular internalization was increased in both MDA-MB-231 and MCF-7 breast cancer cells. These results provide a proof-of-concept evidence that such polymer-based PSi nanocomposite can be extensively used as a promising candidate for intracellular drug delivery. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Physical models of cell motility

    CERN Document Server

    2016-01-01

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

  9. THE MITOCHONDRIAL PARADIGM FOR CARDIOVASCULAR DISEASE SUSCEPTIBILITY AND CELLULAR FUNCTION: A COMPLEMENTARY CONCEPT TO MENDELIAN GENETICS

    OpenAIRE

    Kryzwanski, David M.; Moellering, Douglas; Fetterman, Jessica L.; Dunham-Snary, Kimberly J.; Sammy, Melissa J.; Ballinger, Scott W.

    2011-01-01

    While there is general agreement that cardiovascular disease (CVD) development is influenced by a combination of genetic, environmental, and behavioral contributors, the actual mechanistic basis of how these factors initiate or promote CVD development in some individuals while others with identical risk profiles do not, is not clearly understood. This review considers the potential role for mitochondrial genetics and function in determining CVD susceptibility from the standpoint that the orig...

  10. Tissue architecture and function: dynamic reciprocity via extra- and intra-cellular matrices

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ren; Boudreau, Aaron; Bissell, Mina J

    2008-12-23

    Mammary gland development, functional differentiation, and homeostasis are orchestrated and sustained by a balance of biochemical and biophysical cues from the organ's microenvironment. The three-dimensional microenvironment of the mammary gland, predominantly 'encoded' by a collaboration between the extracellular matrix (ECM), hormones, and growth factors, sends signals from ECM receptors through the cytoskeletal intracellular matrix to nuclear and chromatin structures resulting in gene expression; the ECM in turn is regulated and remodeled by signals from the nucleus. In this chapter, we discuss how coordinated ECM deposition and remodeling is necessary for mammary gland development, how the ECM provides structural and biochemical cues necessary for tissue-specific function, and the role of the cytoskeleton in mediating the extra - to intracellular dialogue occurring between the nucleus and the microenvironment. When operating normally, the cytoskeletal-mediated dynamic and reciprocal integration of tissue architecture and function directs mammary gland development, tissue polarity, and ultimately, tissue-specific gene expression. Cancer occurs when these dynamic interactions go awry for an extended time.

  11. Esophageal motility in eosinophilic esophagitis

    Directory of Open Access Journals (Sweden)

    A.H. Weiss

    2015-07-01

    Conclusions: Motility dysfunction of the esophagus in EoE has not been well reported in the literature and studies have reported conflicting evidence regarding the clinical significance of dysmotility seen in EoE. The correlation between esophageal dysmotility and symptoms of EoE remains unclear. Larger studies are needed to investigate the incidence of esophageal dysmotility, clinical implications, and effect of treatment on patients with EoE.

  12. Hemidesmosomal linker proteins regulate cell motility, invasion and tumorigenicity in oral squamous cell carcinoma derived cells.

    Science.gov (United States)

    Chaudhari, Pratik Rajeev; Charles, Silvania Emlit; D'Souza, Zinia Charlotte; Vaidya, Milind Murlidhar

    2017-11-15

    BPAG1e and Plectin are hemidesmosomal linker proteins which anchor intermediate filament proteins to the cell surface through β4 integrin. Recent reports indicate that these proteins play a role in various cellular processes apart from their known anchoring function. However, the available literature is inconsistent. Further, the previous study from our laboratory suggested that Keratin8/18 pair promotes cell motility and tumor progression by deregulating β4 integrin signaling in oral squamous cell carcinoma (OSCC) derived cells. Based on these findings, we hypothesized that linker proteins may have a role in neoplastic progression of OSCC. Downregulation of hemidesmosomal linker proteins in OSCC derived cells resulted in reduced cell migration accompanied by alterations in actin organization. Further, decreased MMP9 activity led to reduced cell invasion in linker proteins knockdown cells. Moreover, loss of these proteins resulted in reduced tumorigenic potential. SWATH analysis demonstrated upregulation of N-Myc downstream regulated gene 1 (NDRG1) in linker proteins downregulated cells as compared to vector control cells. Further, the defects in phenotype upon linker proteins ablation were rescued upon loss of NDRG1 in linker proteins knockdown background. These data together indicate that hemidesmosomal linker proteins regulate cell motility, invasion and tumorigenicity possibly through NDRG1 in OSCC derived cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The Rcs regulon in Proteus mirabilis: implications for motility, biofilm formation, and virulence.

    Science.gov (United States)

    Howery, Kristen E; Clemmer, Katy M; Rather, Philip N

    2016-11-01

    The overall role of the Rcs phosphorelay in Proteus mirabilis is largely unknown. Previous work had demonstrated that the Rcs phosphorelay represses the flhDC operon and activates the minCDE cell division inhibition system. To identify additional cellular functions regulated by the Rcs phosphorelay, an analysis of RNA-seq data was undertaken. In this report, the results of the RNA-sequencing are discussed with an emphasis on the predicted roles of the Rcs phosphorelay in swarmer cell differentiation, motility, biofilm formation, and virulence. RcsB is shown to activate genes important for differentiation and fimbriae formation, while repressing the expression of genes important for motility and virulence. Additionally, to follow up on the RNA-Seq data, we demonstrate that an rcsB mutant is deficient in its ability to form biofilm and exhibits enhanced virulence in a Galleria mellonella waxworm model. Overall, these results indicate the Rcs regulon in P. mirabilis extends beyond flagellar genes to include those involved in biofilm formation and virulence. Furthermore, the information presented in this study may provide clues to additional roles of the Rcs phosphorelay in other members of the Enterobacteriaceae.

  14. RON kinase isoforms demonstrate variable cell motility in normal cells.

    Science.gov (United States)

    Greenbaum, Alissa; Rajput, Ashwani; Wan, Guanghua

    2016-09-01

    Aberrant RON (Recepteur d'Origine Nantais) tyrosine kinase activation causes the epithelial cell to evade normal growth pathways, resulting in unregulated cell proliferation, increased cell motility and decreased apoptosis. Wildtype (wt) RON has been shown to play a role in metastasis of epithelial malignancies. It presents an important potential therapeutic target for colorectal, breast, gastric and pancreatic cancer. Little is known about functional differences amongst RON isoforms RON155, RON160 and RON165. The purpose of this study was to determine the effect of various RON kinase isoforms on cell motility. Cell lines with stable expression of wtRON were generated by inserting the coding region of RON in pTagRFP (tagged red fluorescence protein plasmid). The expression constructs of RON variants (RON155, RON160 and RON165) were generated by creating a mutagenesis-based wtRON-pTag RFP plasmid and stably transfected into HEK 293 cells. The wound closure scratch assay was used to investigate the effect on cell migratory capacity of wild type RON and its variants. RON transfected cells demonstrated increased cell motility compared to HEK293 control cells. RON165 cell motility was significantly increased compared to RON160 (mean percentage of wound covered 37.37% vs. 32.40%; p = 0.03). RON tyrosine kinase isoforms have variable cell motility. This may reflect a difference in the behavior of malignant epithelial cells and their capacity for metastasis.

  15. Bidirectional motility of the fission yeast kinesin-5, Cut7

    Energy Technology Data Exchange (ETDEWEB)

    Edamatsu, Masaki, E-mail: cedam@mail.ecc.u-tokyo.ac.jp

    2014-03-28

    Highlights: • Motile properties of Cut7 (fission yeast kinesin-5) were studied for the first time. • Half-length Cut7 moved toward plus-end direction of microtubule. • Full-length Cut7 moved toward minus-end direction of microtubule. • N- and C-terminal microtubule binding sites did not switch the motile direction. - Abstract: Kinesin-5 is a homotetrameric motor with its motor domain at the N-terminus. Kinesin-5 crosslinks microtubules and functions in separating spindle poles during mitosis. In this study, the motile properties of Cut7, fission yeast kinesin-5, were examined for the first time. In in vitro motility assays, full-length Cut7 moved toward minus-end of microtubules, but the N-terminal half of Cut7 moved toward the opposite direction. Furthermore, additional truncated constructs lacking the N-terminal or C-terminal regions, but still contained the motor domain, did not switch the motile direction. These indicated that Cut7 was a bidirectional motor, and microtubule binding regions at the N-terminus and C-terminus were not involved in its directionality.

  16. Actin—Towards a Deeper Understanding of the Relationship Between Tissue Context, Cellular Function and Tumorigenesis

    International Nuclear Information System (INIS)

    Spencer, Virginia A.

    2011-01-01

    It is well-established that the actin cytoskeleton plays an important role in tumor development yet the contribution made by nuclear actin is ill-defined. In a recent study, nuclear actin was identified as a key mediator through which laminin type III (LN1) acts to control epithelial cell growth. In the breast, epithelial tumors are surrounded by an environment which lacks LN1. These findings point to actin as a potential mediator of tumor development. Here our current understanding of the roles of cytoplasmic and nuclear actin in normal and tumor cell growth is reviewed, relating these functions to cell phenotype in a tissue context

  17. Inhibition of the alpha-ketoglutarate dehydrogenase complex alters mitochondrial function and cellular calcium regulation.

    Science.gov (United States)

    Huang, Hsueh-Meei; Zhang, Hui; Xu, Hui; Gibson, Gary E

    2003-01-20

    Mitochondrial dysfunction occurs in many neurodegenerative diseases. The alpha-ketoglutarate dehydrogenase complex (KGDHC) catalyzes a key and arguably rate-limiting step of the tricarboxylic acid cycle (TCA). A reduction in the activity of the KGDHC occurs in brains and cells of patients with many of these disorders and may underlie the abnormal mitochondrial function. Abnormalities in calcium homeostasis also occur in fibroblasts from Alzheimer's disease (AD) patients and in cells bearing mutations that lead to AD. Thus, the present studies test whether the reduction of KGDHC activity can lead to the alterations in mitochondrial function and calcium homeostasis. alpha-Keto-beta-methyl-n-valeric acid (KMV) inhibits KGDHC activity in living N2a cells in a dose- and time-dependent manner. Surprisingly, concentration of KMV that inhibit in situ KGDHC by 80% does not alter the mitochondrial membrane potential (MMP). However, similar concentrations of KMV induce the release of cytochrome c from mitochondria into the cytosol, reduce basal [Ca(2+)](i) by 23% (Pcalcium release from the endoplasmic reticulum (ER) by 46% (P<0.005). This result suggests that diminished KGDHC activities do not lead to the Ca(2+) abnormalities in fibroblasts from AD patients or cells bearing PS-1 mutations. The increased release of cytochrome c with diminished KGDHC activities will be expected to activate other pathways including cell death cascades. Reductions in this key mitochondrial enzyme will likely make the cells more vulnerable to metabolic insults that promote cell death.

  18. The phosphoproteome of Aspergillus nidulans reveals functional association with cellular processes involved in morphology and secretion.

    Science.gov (United States)

    Ramsubramaniam, Nikhil; Harris, Steven D; Marten, Mark R

    2014-11-01

    We describe the first phosphoproteome of the model filamentous fungus Aspergillus nidulans. Phosphopeptides were enriched using titanium dioxide, separated using a convenient ultra-long reverse phase gradient, and identified using a "high-high" strategy (high mass accuracy on the parent and fragment ions) with higher-energy collisional dissociation. Using this approach 1801 phosphosites, from 1637 unique phosphopeptides, were identified. Functional classification revealed phosphoproteins were overrepresented under GO categories related to fungal morphogenesis: "sites of polar growth," "vesicle mediated transport," and "cytoskeleton organization." In these same GO categories, kinase-substrate analysis of phosphoproteins revealed the majority were target substrates of CDK and CK2 kinase families, indicating these kinase families play a prominent role in fungal morphogenesis. Kinase-substrate analysis also identified 57 substrates for kinases known to regulate secretion of hydrolytic enzymes (e.g. PkaA, SchA, and An-Snf1). Altogether this data will serve as a benchmark that can be used to elucidate regulatory networks functionally associated with fungal morphogenesis and secretion. All MS data have been deposited in the ProteomeXchange with identifier PXD000715 (http://proteomecentral.proteomexchange.org/dataset/PXD000715). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Silk sericin-alginate-chitosan microcapsules: hepatocytes encapsulation for enhanced cellular functions.

    Science.gov (United States)

    Nayak, Sunita; Dey, Sanchareeka; Kundu, Subhas C

    2014-04-01

    The encapsulation based technology permits long-term delivery of desired therapeutic products in local regions of body without the need of immunosuppressant drugs. In this study microcapsules composed of sericin and alginate micro bead as inner core and with an outer chitosan shell are prepared. This work is proposed for live cell encapsulation for potential therapeutic applications. The sericin protein is obtained from cocoons of non-mulberry silkworm Antheraea mylitta. The sericin-alginate micro beads are prepared via ionotropic gelation under high applied voltage. The beads further coated with chitosan and crosslinked with genipin. The microcapsules developed are nearly spherical in shape with smooth surface morphology. Alamar blue assay and confocal microscopy indicate high cell viability and uniform encapsulated cell distribution within the sericin-alginate-chitosan microcapsules indicating that the microcapsules maintain favourable microenvironment for the cells. The functional analysis of encapsulated cells demonstrates that the glucose consumption, urea secretion rate and intracellular albumin content increased in the microcapsules. The study suggests that the developed sericin-alginate-chitosan microcapsule contributes towards the development of cell encapsulation model. It also offers to generate enriched population of metabolically and functionally active cells for the future therapeutics especially for hepatocytes transplantation in acute liver failure. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Low density of membrane particles in auditory hair cells of lizards and birds suggests an absence of somatic motility.

    Science.gov (United States)

    Köppl, Christine; Forge, Andrew; Manley, Geoffrey A

    2004-11-08

    Hair cells are the mechanoreceptive cells of the vertebrate lateral line and inner ear. In addition to their sensory function, hair cells display motility and thus themselves generate mechanical energy, which is thought to enhance sensitivity. Two principal cellular mechanism are known that can mediate hair-cell motility in vitro. One of these is based on voltage-dependent changes of an intramembrane protein and has so far been demonstrated only in outer hair cells of the mammalian cochlea. Correlated with this, the cell membranes of outer hair cells carry an extreme density of embedded particles, as revealed by freeze fracturing. The present study explored the possibility of membrane-based motility in hair cells of nonmammals, by determining their density of intramembrane particles. Replicas of freeze-fractured membrane were prepared from auditory hair cells of a lizard, the Tokay gecko, and a bird, the barn owl. These species were chosen because of independent evidence for active cochlear mechanics, in the form of spontaneous otoacoustic emissions. For quantitative comparison, mammalian inner and outer hair cells, as well as vestibular hair, cells were reevaluated. Lizard and bird hair cells displayed median densities of 2,360 and 1,880 intramembrane particles/microm2, respectively. This was not significantly different from the densities in vestibular and mammalian inner hair cells; however, it was about half the density in of mammalian outer hair cells. This suggests that nonmammalian hair cells do not possess high densities of motor protein in their membranes and are thus unlikely to be capable of somatic motility. 2004 Wiley-Liss, Inc.

  1. The zebrafish miR-125c is induced under hypoxic stress via hypoxia-inducible factor 1α and functions in cellular adaptations and embryogenesis.

    Science.gov (United States)

    He, Yan; Huang, Chun-Xiao; Chen, Nan; Wu, Meng; Huang, Yan; Liu, Hong; Tang, Rong; Wang, Wei-Min; Wang, Huan-Ling

    2017-09-26

    Hypoxia is a unique environmental stress. Hypoxia inducible factor-lα (HIF-lα) is a major transcriptional regulator of cellular adaptations to hypoxic stress. MicroRNAs (miRNAs) as posttranscriptional gene expression regulators occupy a crucial role in cell survival under low-oxygen environment. Previous evidences suggested that miR-125c is involved in hypoxia adaptation, but its precise biological roles and the regulatory mechanism underlying hypoxic responses remain unknown. The present study showed that zebrafish miR-125c is upregulated by hypoxia in a Hif-lα-mediated manner in vitro and in vivo . Dual-luciferase assay revealed that cdc25a is a novel target of miR-125c. An inverse correlation between miR-125c and cdc25a was further confirmed in vivo , suggesting miR-125c as a crucial physiological inhibitor of cdc25a which responds to cellular hypoxia. Overexpression of miR-125c suppressed cell proliferation, led to cell cycle arrest at the G1 phase in ZF4 cells and induced apoptotic responses during embryo development. More importantly, miR-125c overexpression resulted in severe malformation and reduction of motility during zebrafish embryonic development. Taken together, we conclude that miR-125c plays a pivotal role in cellular adaptations to hypoxic stress at least in part through the Hif-1α/miR-125c/cdc25a signaling and has great impact on zebrafish early embryonic development.

  2. Bacillus subtilis Hfq: A role in chemotaxis and motility

    Indian Academy of Sciences (India)

    2016-07-16

    Jul 16, 2016 ... motility, thus assigning a new function for Hfq in B. subtilis. 1. Introduction. Hfq in ... to play a role in pathogenecity in mice, tolerance to osmotic and ethanol stress ...... in B. subtilis is characterized by events like surfactin pro- duction .... SM Cutting (New York: John Wiley and Sons Inc) pp 442–444. Nicolas P ...

  3. The Persistent Contributions of RNA to Eukaryotic Gen(om)e Architecture and Cellular Function

    Science.gov (United States)

    Brosius, Jürgen

    2014-01-01

    Currently, the best scenario for earliest forms of life is based on RNA molecules as they have the proven ability to catalyze enzymatic reactions and harbor genetic information. Evolutionary principles valid today become apparent in such models already. Furthermore, many features of eukaryotic genome architecture might have their origins in an RNA or RNA/protein (RNP) world, including the onset of a further transition, when DNA replaced RNA as the genetic bookkeeper of the cell. Chromosome maintenance, splicing, and regulatory function via RNA may be deeply rooted in the RNA/RNP worlds. Mostly in eukaryotes, conversion from RNA to DNA is still ongoing, which greatly impacts the plasticity of extant genomes. Raw material for novel genes encoding protein or RNA, or parts of genes including regulatory elements that selection can act on, continues to enter the evolutionary lottery. PMID:25081515

  4. Heparan sulfate proteoglycans on the cell surface: versatile coordinators of cellular functions

    DEFF Research Database (Denmark)

    Tumova, S; Woods, A; Couchman, J R

    2000-01-01

    Heparan sulfate proteoglycans are complex molecules composed of a core protein with covalently attached glycosaminoglycan chains. While the protein part determines localization of the proteoglycan on the cell surfaces or in the extracellular matrix, the glycosaminoglycan component, heparan sulfate......, mediates interactions with a variety of extracellular ligands such as growth factors and adhesion molecules. Through these interactions, heparan sulfate proteoglycans participate in many events during cell adhesion, migration, proliferation and differentiation. We are determining the multitude...... of proteoglycan functions, as their intricate roles in many pathways are revealed. They act as coreceptors for growth factors, participate in signalling during cell adhesion, modulate the activity of a broad range of molecules, and partake in many developmental and pathological processes, including tumorigenesis...

  5. From centriole biogenesis to cellular function: centrioles are essential for cell division at critical developmental stages.

    Science.gov (United States)

    Rodrigues-Martins, Ana; Riparbelli, Maria; Callaini, Giuliano; Glover, David M; Bettencourt-Dias, Monica

    2008-01-01

    Centrioles are essential for the formation of cilia, flagella and centrosome organization. Abnormalities in centrosome structure and number in many cancers can be associated with aberrant cell division and genomic instability.(1,2) Canonical centriole duplication occurs in coordination with the cell division cycle, such that a single new "daughter" centriole arises next to each "mother" centriole. If destroyed, or eliminated during development, centrioles can form de novo.(3-5) Here we discuss our recent data demonstrating a molecular pathway that operates in both de novo and canonical centriole biogenesis involving SAK/PLK4, SAS-6 and SAS-4.(6) We showed that centriole biogenesis is a self-assembly process locally triggered by high SAK/PLK4 activity that may or not be associated with an existing centriole. SAS-6 acts downstream of SAK/PLK4 to organize nine precentriolar units, which we call here enatosomes, fitting together laterally and longitudinally, specifying a tube-like centriole precursor.(7,8) The identification of mutants impaired in centriole biogenesis has permitted the study of the physiological consequences of their absence in the whole organism. In Drosophila, centrioles are not necessary for somatic cell divisions.(9,10) However, we show here that mitotic abnormalities arise in syncytial SAK/PLK4-derived mutant embryos resulting in lethality. Moreover male meiosis fails in both SAK/PLK4 and DSAS-4 mutant spermatids that have no centrioles. These results show diversity in the need for centrioles in cell division. This suggests that tissue specific constraints selected for different contributions of centrosome-independent and dependent mechanisms in spindle function. This heterogeneity should be taken into account both in reaching an understanding of spindle function and when designing drugs that target cell division.

  6. hemingway is required for sperm flagella assembly and ciliary motility in Drosophila.

    Science.gov (United States)

    Soulavie, Fabien; Piepenbrock, David; Thomas, Joëlle; Vieillard, Jennifer; Duteyrat, Jean-Luc; Cortier, Elisabeth; Laurençon, Anne; Göpfert, Martin C; Durand, Bénédicte

    2014-04-01

    Cilia play major functions in physiology and development, and ciliary dysfunctions are responsible for several diseases in humans called ciliopathies. Cilia motility is required for cell and fluid propulsion in organisms. In humans, cilia motility deficiencies lead to primary ciliary dyskinesia, with upper-airways recurrent infections, left-right asymmetry perturbations, and fertility defects. In Drosophila, we identified hemingway (hmw) as a novel component required for motile cilia function. hmw encodes a 604-amino acid protein characterized by a highly conserved coiled-coil domain also found in the human orthologue, KIAA1430. We show that HMW is conserved in species with motile cilia and that, in Drosophila, hmw is expressed in ciliated sensory neurons and spermatozoa. We created hmw-knockout flies and found that they are hearing impaired and male sterile. hmw is implicated in the motility of ciliated auditory sensory neurons and, in the testis, is required for elongation and maintenance of sperm flagella. Because HMW is absent from mature flagella, we propose that HMW is not a structural component of the motile axoneme but is required for proper acquisition of motile properties. This identifies HMW as a novel, evolutionarily conserved component necessary for motile cilium function and flagella assembly.

  7. An Amphipathic Helix Directs Cellular Membrane Curvature Sensing and Function of the BAR Domain Protein PICK1.

    Science.gov (United States)

    Herlo, Rasmus; Lund, Viktor K; Lycas, Matthew D; Jansen, Anna M; Khelashvili, George; Andersen, Rita C; Bhatia, Vikram; Pedersen, Thomas S; Albornoz, Pedro B C; Johner, Niklaus; Ammendrup-Johnsen, Ina; Christensen, Nikolaj R; Erlendsson, Simon; Stoklund, Mikkel; Larsen, Jannik B; Weinstein, Harel; Kjærulff, Ole; Stamou, Dimitrios; Gether, Ulrik; Madsen, Kenneth L

    2018-05-15

    BAR domains are dimeric protein modules that sense, induce, and stabilize lipid membrane curvature. Here, we show that membrane curvature sensing (MCS) directs cellular localization and function of the BAR domain protein PICK1. In PICK1, and the homologous proteins ICA69 and arfaptin2, we identify an amphipathic helix N-terminal to the BAR domain that mediates MCS. Mutational disruption of the helix in PICK1 impaired MCS without affecting membrane binding per se. In insulin-producing INS-1E cells, super-resolution microscopy revealed that disruption of the helix selectively compromised PICK1 density on insulin granules of high curvature during their maturation. This was accompanied by reduced hormone storage in the INS-1E cells. In Drosophila, disruption of the helix compromised growth regulation. By demonstrating size-dependent binding on insulin granules, our finding highlights the function of MCS for BAR domain proteins in a biological context distinct from their function, e.g., at the plasma membrane during endocytosis. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  8. Cellular function reinstitution of offspring red blood cells cloned from the sickle cell disease patient blood post CRISPR genome editing

    Directory of Open Access Journals (Sweden)

    Jianguo Wen

    2017-06-01

    Full Text Available Abstract Background Sickle cell disease (SCD is a disorder of red blood cells (RBCs expressing abnormal hemoglobin-S (HbS due to genetic inheritance of homologous HbS gene. However, people with the sickle cell trait (SCT carry a single allele of HbS and do not usually suffer from SCD symptoms, thus providing a rationale to treat SCD. Methods To validate gene therapy potential, hematopoietic stem cells were isolated from the SCD patient blood and treated with CRISPR/Cas9 approach. To precisely dissect genome-editing effects, erythroid progenitor cells were cloned from single colonies of CRISPR-treated cells and then expanded for simultaneous gene, protein, and cellular function studies. Results Genotyping and sequencing analysis revealed that the genome-edited erythroid progenitor colonies were converted to SCT genotype from SCD genotype. HPLC protein assays confirmed reinstallation of normal hemoglobin at a similar level with HbS in the cloned genome-edited erythroid progenitor cells. For cell function evaluation, in vitro RBC differentiation of the cloned erythroid progenitor cells was induced. As expected, cell sickling assays indicated function reinstitution of the genome-edited offspring SCD RBCs, which became more resistant to sickling under hypoxia condition. Conclusions This study is an exploration of genome editing of SCD HSPCs.

  9. Application of TALE-Based Approach for Dissecting Functional MicroRNA-302/367 in Cellular Reprogramming.

    Science.gov (United States)

    Zhang, Zhonghui; Wu, Wen-Shu

    2018-01-01

    MicroRNAs are small 18-24 nt single-stranded noncoding RNA molecules involved in many biological processes, including stemness maintenance and cellular reprogramming. Current methods used in loss-of-function studies of microRNAs have several limitations. Here, we describe a new approach for dissecting miR-302/367 functions by transcription activator-like effectors (TALEs), which are natural effector proteins secreted by Xanthomonas and Ralstonia bacteria. Knockdown of the miR-302/367 cluster uses the Kruppel-associated box repressor domain fused with specific TALEs designed to bind the miR-302/367 cluster promoter. Knockout of the miR-302/367 cluster uses two pairs of TALE nucleases (TALENs) to delete the miR-302/367 cluster in human primary cells. Together, both TALE-based transcriptional repressor and TALENs are two promising approaches for loss-of-function studies of microRNA cluster in human primary cells.

  10. A Phylogenomic Census of Molecular Functions Identifies Modern Thermophilic Archaea as the Most Ancient Form of Cellular Life

    Directory of Open Access Journals (Sweden)

    Arshan Nasir

    2014-01-01

    Full Text Available The origins of diversified life remain mysterious despite considerable efforts devoted to untangling the roots of the universal tree of life. Here we reconstructed phylogenies that described the evolution of molecular functions and the evolution of species directly from a genomic census of gene ontology (GO definitions. We sampled 249 free-living genomes spanning organisms in the three superkingdoms of life, Archaea, Bacteria, and Eukarya, and used the abundance of GO terms as molecular characters to produce rooted phylogenetic trees. Results revealed an early thermophilic origin of Archaea that was followed by genome reduction events in microbial superkingdoms. Eukaryal genomes displayed extraordinary functional diversity and were enriched with hundreds of novel molecular activities not detected in the akaryotic microbial cells. Remarkably, the majority of these novel functions appeared quite late in evolution, synchronized with the diversification of the eukaryal superkingdom. The distribution of GO terms in superkingdoms confirms that Archaea appears to be the simplest and most ancient form of cellular life, while Eukarya is the most diverse and recent.

  11. A phylogenomic census of molecular functions identifies modern thermophilic archaea as the most ancient form of cellular life.

    Science.gov (United States)

    Nasir, Arshan; Kim, Kyung Mo; Caetano-Anollés, Gustavo

    2014-01-01

    The origins of diversified life remain mysterious despite considerable efforts devoted to untangling the roots of the universal tree of life. Here we reconstructed phylogenies that described the evolution of molecular functions and the evolution of species directly from a genomic census of gene ontology (GO) definitions. We sampled 249 free-living genomes spanning organisms in the three superkingdoms of life, Archaea, Bacteria, and Eukarya, and used the abundance of GO terms as molecular characters to produce rooted phylogenetic trees. Results revealed an early thermophilic origin of Archaea that was followed by genome reduction events in microbial superkingdoms. Eukaryal genomes displayed extraordinary functional diversity and were enriched with hundreds of novel molecular activities not detected in the akaryotic microbial cells. Remarkably, the majority of these novel functions appeared quite late in evolution, synchronized with the diversification of the eukaryal superkingdom. The distribution of GO terms in superkingdoms confirms that Archaea appears to be the simplest and most ancient form of cellular life, while Eukarya is the most diverse and recent.

  12. Effects of cryopreservation on excretory function, cellular adhesion molecules and vessel lumen formation in human umbilical vein endothelial cells.

    Science.gov (United States)

    Cai, Guoping; Lai, Binbin; Hong, Huaxing; Lin, Peng; Chen, Weifu; Zhu, Zhong; Chen, Haixiao

    2017-07-01

    Cryopreservation is widely used in regenerative medicine for tissue preservation. In the present study, the effects of cryopreservation on excretory function, cellular adhesion molecules and vessel lumen formation in human umbilical vein endothelial cells (HUVECs) were investigated. After 0, 4, 8, 12 or 24 weeks of cryopreservation in liquid nitrogen, the HUVECs were thawed. The excretory functions markers (endothelin‑1, prostaglandin E1, von Willebrand factor and nitric oxide) of HUVECs were measured by ELISA assay. The expression of intercellular adhesion molecule‑1 (ICAM‑1) in HUVECs was analyzed using flow cytometry. An angiogenesis assay was used to determine the angiogeneic capabilities of the thawed HUVECs. The results demonstrated that cryopreserved/thawed and recultivated HUVECs were unsuitable for tissue‑engineered microvascular construction. Specifically, the excretory function of the cells was significantly decreased in the post‑cryopreserved HUVECs at 24 weeks. In addition, the level of ICAM‑1 in HUVECs was significantly upregulated from the fourth week of cryopreservation. Furthermore, the tube‑like structure‑forming potential was weakened with increasing cryopreservation duration, and the numbers of lumen and the length of the pipeline were decreased in the thawed HUVECs, in a time‑dependent manner. In conclusion, the results of the present study revealed that prolonged cryopreservation may lead to HUVEC dysfunction and did not create stable cell lines for tissue‑engineered microvascular construction.

  13. Active subsurface cellular function in the Baltic Sea Basin, IODP Exp 347

    Science.gov (United States)

    Reese, B. K.; Zinke, L. A.; Bird, J. T.; Lloyd, K. G.; Marshall, I.; Amend, J.; Jørgensen, B. B.

    2016-12-01

    The Baltic Sea Basin is a unique depositional setting that has experienced periods of glaciation and deglaciation as a result of global temperature fluctuations over the course of several hundred thousand years. This has resulted in laminated sediments formed during periods with strong permanent salinity stratification. The high sedimentation rates (100-500 cm/1000 y) make this an ideal setting to understand the microbial structure of a deep biosphere community in a high-organic matter environment. The responses of deep sediment microbial communities to variations in conditions during and after deposition are poorly understood. Samples were collected through scientific drilling during the International Ocean Discovery Program (IODP) Expedition 347 on board the Greatship Manisha, September-November 2013. We examined the active microbial community structure using the 16S rRNA gene transcript and active functional genes through metatranscriptome sequencing. Major biogeochemical shifts have been observed in response to the depositional history between the limnic, brackish, and marine phases. The microbial community structure in the BSB is diverse and reflective of the unique changes in the geochemical profile. These data further define the existence life in the deep subsurface and the survival mechanisms required for this extreme environment.

  14. The ubiquitous presence of exopolygalacturonase in maize suggests a fundamental cellular function for this enzyme.

    Science.gov (United States)

    Dubald, M; Barakate, A; Mandaron, P; Mache, R

    1993-11-01

    Exopolygalacturonase (exoPG) is a pectin-degrading enzyme abundant in maize pollen. Using immunochemistry and in situ hybridization it is shown that in addition to its presence in pollen, exoPG is also present in sporophytic tissues, such as the tapetum and mesophyll cells. The enzyme is located in the cytoplasm of pollen and of some mesophyll cells. In other mesophyll cells, the tapetum and the pollen tube, exoPG is located in the cell wall. The measurement of enzyme activity shows that exoPG is ubiquitous in the vegetative organs. These results suggest a general function for exoPG in cell wall edification or degradation. ExoPG is encoded by a closely related multigene family. The regulation of the expression of one of the exoPG genes was analyzed in transgenic tobacco. Reporter GUS activity was detected in anthers, seeds and stems but not in leaves or roots of transgenic plants. This strongly suggests that the ubiquitous presence of exoPG in maize is the result of the expression of different exoPG genes.

  15. In-vitro cytotoxicity and cellular uptake studies of luminescent functionalized core-shell nanospheres

    Directory of Open Access Journals (Sweden)

    Anees A. Ansari

    2017-09-01

    Full Text Available Monodispersed luminescent functionalized core-shell nanospheres (LFCSNs were successfully synthesized and investigated for their cyto-toxic effect on human liver hepatocellular carcinoma cell line (HepG2 cells by adopting MTT, DNA Ladder, TUNEL assay and qPCR based gene expressions through mRNA quantifications. The TUNEL and DNA ladder assays suggested an insignificant apoptosis in HepG2 cells due to the LFCSNs treatment. Further, the qPCR results also show that the mRNA expressions of cell cycle checkpoint gene p53 and apoptosis related gene (caspase-9 was up-regulated, while the antiapoptotic gene BCl-2 and apoptosis related genes FADD and CAS-3 (apoptosis effecter gene were down-regulated in the LFCSNs treated cells. The nanospheres that were loaded into the cells confirm their intracellular uptake by light and fluorescent spectro-photometry and microscopy imaging analysis. The loaded nanospheres demonstrate an absolute resistance to photo-bleaching, which were applied for dynamic imaging to real-time tracking in-vitro cell migratory activity for continuous 24 and 48 h durations using a time-lapsed fluorescent microscope. These properties of LFCSNs could therefore promote applications in the area of fluorescent protein biolabeling and drug-delivery.

  16. Role of Myeloperoxidase Oxidants in the Modulation of Cellular Lysosomal Enzyme Function

    DEFF Research Database (Denmark)

    Ismael, Fahd O; Barrett, Tessa J; Sheipouri, Diba

    2016-01-01

    with the development of atherosclerosis. In this study, we examined the effect of HOCl, HOSCN and LDL pre-treated with these oxidants on the function of lysosomal enzymes responsible for protein catabolism and lipid hydrolysis in murine macrophage-like J774A.1 cells. In each case, the cells were exposed to HOCl...... or HOSCN or LDL pre-treated with these oxidants. Lysosomal cathepsin (B, L and D) and acid lipase activities were quantified, with cathepsin and LAMP-1 protein levels determined by Western blotting. Exposure of J774A.1 cells to HOCl or HOSCN resulted in a significant decrease in the activity of the Cys......-dependent cathepsins B and L, but not the Asp-dependent cathepsin D. Cathepsins B and L were also inhibited in macrophages exposed to HOSCN-modified, and to a lesser extent, HOCl-modified LDL. No change was seen in cathepsin D activity or the expression of the cathepsin proteins or lysosomal marker protein LAMP-1...

  17. A Protoplast Transient Expression System to Enable Molecular, Cellular, and Functional Studies in Phalaenopsis orchids

    Directory of Open Access Journals (Sweden)

    Hsiang-Yin Lin

    2018-06-01

    Full Text Available The enigmatic nature of the specialized developmental programs of orchids has fascinated plant biologists for centuries. The recent releases of orchid genomes indicate that orchids possess new gene families and family expansions and contractions to regulate a diverse suite of developmental processes. However, the extremely long orchid life cycle and lack of molecular toolkit have hampered the advancement of orchid biology research. To overcome the technical difficulties and establish a platform for rapid gene regulation studies, in this study, we developed an efficient protoplast isolation and transient expression system for Phalaenopsis aphrodite. This protocol was successfully applied to protein subcellular localization and protein–protein interaction studies. Moreover, it was confirmed to be useful in delineating the PaE2F/PaDP-dependent cell cycle pathway and studying auxin response. In summary, the established orchid protoplast transient expression system provides a means to functionally characterize orchid genes at the molecular level allowing assessment of transcriptome responses to transgene expression and widening the scope of molecular studies in orchids.

  18. Cellular function and signaling pathways of vascular smooth muscle cells modulated by sphingosine 1-phosphate

    Directory of Open Access Journals (Sweden)

    Takuji Machida

    2016-12-01

    Full Text Available Sphingosine 1-phosphate (S1P plays important roles in cardiovascular pathophysiology. S1P1 and/or S1P3, rather than S1P2 receptors, seem to be predominantly expressed in vascular endothelial cells, while S1P2 and/or S1P3, rather than S1P1 receptors, seem to be predominantly expressed in vascular smooth muscle cells (VSMCs. S1P has multiple actions, such as proliferation, inhibition or stimulation of migration, and vasoconstriction or release of vasoactive mediators. S1P induces an increase of the intracellular Ca2+ concentration in many cell types, including VSMCs. Activation of S1P3 seems to play an important role in Ca2+ mobilization. S1P induces cyclooxygenase-2 expression in VSMCs via both S1P2 and S1P3 receptors. S1P2 receptor activation in VSMCs inhibits inducible nitric oxide synthase (iNOS expression. At the local site of vascular injury, vasoactive mediators such as prostaglandins and NO produced by VSMCs are considered primarily as a defensive and compensatory mechanism for the lack of endothelial function to prevent further pathology. Therefore, selective S1P2 receptor antagonists may have the potential to be therapeutic agents, in view of their antagonism of iNOS inhibition by S1P. Further progress in studies of the precise mechanisms of S1P may provide useful knowledge for the development of new S1P-related drugs for the treatment of cardiovascular diseases.

  19. High LET radiation shows no major cellular and functional effects on primary cardiomyocytes in vitro

    Science.gov (United States)

    Heselich, Anja; Frieß, Johannes L.; Ritter, Sylvia; Benz, Naja P.; Layer, Paul G.; Thielemann, Christiane

    2018-02-01

    It is well known that ionizing radiation causes adverse effects on various mammalian tissues. However, there is little information on the biological effects of heavy ion radiation on the heart. In order to fill this gap, we systematically examined DNA-damage induction and repair, as well as proliferation and apoptosis in avian cardiomyocyte cultures irradiated with heavy ions such as titanium and iron, relevant for manned space-flight, and carbon ions, as used for radiotherapy. Further, and to our knowledge for the first time, we analyzed the effect of heavy ion radiation on the electrophysiology of primary cardiomyocytes derived from chicken embryos using the non-invasive microelectrode array (MEA) technology. As electrophysiological endpoints beat rate and field action potential duration were analyzed. The cultures clearly exhibited the capacity to repair induced DNA damage almost completely within 24 h, even at doses of 7 Gy, and almost completely recovered from radiation-induced changes in proliferative behavior. Interestingly, no significant effects on apoptosis could be detected. Especially the functionality of primary cardiac cells exhibited a surprisingly high robustness against heavy ion radiation, even at doses of up to 7 Gy. In contrast to our previous study with X-rays the beat rate remained more or less unaffected after heavy ion radiation, independently of beam quality. The only change we could observe was an increase of the field action potential duration of up to 30% after titanium irradiation, diminishing within the following three days. This potentially pathological observation may be an indication that heavy ion irradiation at high doses could bear a long-term risk for cardiovascular disease induction.

  20. The E-domain region of mechano-growth factor inhibits cellular apoptosis and preserves cardiac function during myocardial infarction.

    Science.gov (United States)

    Mavrommatis, Evangelos; Shioura, Krystyna M; Los, Tamara; Goldspink, Paul H

    2013-09-01

    Insulin-like growth factor-1 (IGF-1) isoforms are expressed via alternative splicing. Expression of the minor isoform IGF-1Eb [also known as mechano-growth factor (MGF)] is responsive to cell stress. Since IGF-1 isoforms differ in their E-domain regions, we are interested in determining the biological function of the MGF E-domain. To do so, a synthetic peptide analog was used to gain mechanistic insight into the actions of the E-domain. Treatment of H9c2 cells indicated a rapid cellular uptake mechanism that did not involve IGF-1 receptor activation but resulted in a nuclear localization. Peptide treatment inhibited the intrinsic apoptotic pathway in H9c2 cells subjected to cell stress with sorbitol by preventing the collapse of the mitochondrial membrane potential and inhibition of caspase-3 activation. Therefore, we administered the peptide at the time of myocardial infarction (MI) in mice. At 2 weeks post-MI cardiac function, gene expression and cell death were assayed. A significant decline in both systolic and diastolic function was evident in untreated mice based on PV loop analysis. Delivery of the E-peptide ameliorated the decline in function and resulted in significant preservation of cardiac contractility. Associated with these changes were an inhibition of pathologic hypertrophy and significantly fewer apoptotic nuclei in the viable myocardium of E-peptide-treated mice post-MI. We conclude that administration of the MGF E-domain peptide may provide a means of modulating local tissue IGF-1 autocrine/paracrine actions to preserve cardiac function, prevent cell death, and pathologic remodeling in the heart.

  1. Study on the enhanced cellular uptake effect of daunorubicin on leukemia cells mediated via functionalized nickel nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Guo Dadong; Wu Chunhui; Hu Hongli; Wang Xuemei [State Key Lab of Bioelectronics (Chien-Shiung Wu Lab), Southeast University, Nanjing 210096 (China); Li Xiaomao [Department of Physics, University of Saarland, D-66041 Saarbruecken (Germany); Chen Baoan, E-mail: xuewang@seu.edu.c [Zhongda Hospital, School of Clinical Medical, Southeast University, Nanjing 210096 (China)

    2009-04-15

    The success of cancer chemotherapy is largely dependent on the efficient anticancer drug accumulation in target tumor tissues and cells so as to inhibit the proliferation of the cancer cells. Recently, some biocompatible nanomaterials have been utilized as drug target delivery systems and have shown the great potential to effectively afford the sustained drug delivery for the target cancer cells. In this study, we have explored the possibility for the bio-application of the functionalized nickel (Ni) nanoparticles and the efficiency of the functionalized Ni nanoparticles on drug permeability, and cellular uptake of leukemia K562 cells in vitro has been probed via atomic force microscopy, inverted fluorescence microscopy and confocal microscopy, electrochemical study and MTT (3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl-tetrazolium bromide) assay. It is observed that the presence of relevant Ni nanoparticles could induce the membrane structure change of target cells and efficiently improve the permeability of the cell membrane so that the combination of these Ni nanoparticles with anticancer drug daunorubicin could have a synergistic effect on the efficient cytotoxicity suppression in leukemia cancer cells. These observations indicate the great potential of Ni nanoparticles in the future biomedical application including target cancer diagnosis and chemotherapy.

  2. The application of multiple biophysical cues to engineer functional neocartilage for treatment of osteoarthritis. Part I: cellular response.

    Science.gov (United States)

    Brady, Mariea A; Waldman, Stephen D; Ethier, C Ross

    2015-02-01

    Osteoarthritis (OA) is a complex disease of the joint for which current treatments are unsatisfactory, thus motivating development of tissue engineering (TE)-based therapies. To date, TE strategies have had some success, developing replacement tissue constructs with biochemical properties approaching that of native cartilage. However, poor biomechanical properties and limited postimplantation integration with surrounding tissue are major shortcomings that need to be addressed. Functional tissue engineering strategies that apply physiologically relevant biophysical cues provide a platform to improve TE constructs before implantation. In the previous decade, new experimental and theoretical findings in cartilage biomechanics and electromechanics have emerged, resulting in an increased understanding of the complex interplay of multiple biophysical cues in the extracellular matrix of the tissue. The effect of biophysical stimulation on cartilage, and the resulting chondrocyte-mediated biosynthesis, remodeling, degradation, and repair, has, therefore, been extensively explored by the TE community. This article compares and contrasts the cellular response of chondrocytes to multiple biophysical stimuli, and may be read in conjunction with its companion paper that compares and contrasts the subsequent intracellular signal transduction cascades. Mechanical, magnetic, and electrical stimuli promote proliferation, differentiation, and maturation of chondrocytes within established dose parameters or "biological windows." This knowledge will provide a framework for ongoing studies incorporating multiple biophysical cues in TE functional neocartilage for treatment of OA.

  3. HAVCR1 (CD365) and Its Mouse Ortholog Are Functional Hepatitis A Virus (HAV) Cellular Receptors That Mediate HAV Infection.

    Science.gov (United States)

    Costafreda, Maria Isabel; Kaplan, Gerardo

    2018-05-01

    The hepatitis A virus (HAV) cellular receptor 1 (HAVCR1), classified as CD365, was initially discovered as an HAV cellular receptor using an expression cloning strategy. Due to the lack of HAV receptor-negative replication-competent cells, it was not possible to fully prove that HAVCR1 was a functional HAV receptor. However, biochemistry, classical virology, and epidemiology studies further supported the functional role of HAVCR1 as an HAV receptor. Here, we show that an anti-HAVCR1 monoclonal antibody that protected African green monkey kidney (AGMK) cells against HAV infection only partially protected monkey Vero E6 cells and human hepatoma Huh7 cells, indicating that these two cell lines express alternative yet unidentified HAV receptors. Therefore, we focused our work on AGMK cells to further characterize the function of HAVCR1 as an HAV receptor. Advances in clustered regularly interspaced short palindromic repeat/Cas9 technology allowed us to knock out the monkey ortholog of HAVCR1 in AGMK cells. The resulting AGMK HAVCR1 knockout (KO) cells lost susceptibility to HAV infection, including HAV-free viral particles (vpHAV) and exosomes purified from HAV-infected cells (exo-HAV). Transfection of HAVCR1 cDNA into AGMK HAVCR1 KO cells restored susceptibility to vpHAV and exo-HAV infection. Furthermore, transfection of the mouse ortholog of HAVCR1, mHavcr1, also restored the susceptibility of AGMK HAVCR1 KO cells to HAV infection. Taken together, our data clearly show that HAVCR1 and mHavcr1 are functional HAV receptors that mediate HAV infection. This work paves the way for the identification of alternative HAV receptors to gain a complete understanding of their interplay with HAVCR1 in the cell entry and pathogenic processes of HAV. IMPORTANCE HAVCR1, an HAV receptor, is expressed in different cell types, including regulatory immune cells and antigen-presenting cells. How HAV evades the immune response during a long incubation period of up to 4 weeks and the

  4. Effect of enhanced UV-B radiation on motile microorganisms

    International Nuclear Information System (INIS)

    Haeder, D.P.

    1985-02-01

    The effect of slightly increased UV-B radiation was studied in four taxonomically very different microorganisms: the gliding prokaryotic cyanobacterium, Phormidium, the unicellular green alga Cosmarium, the flagellate Euglena and the cellular slime mold Dictyostelium. UV-B doses which can be expected as a result of a slight decrease of the protective ozone layer in the stratosphere, do not kill or damage the microorganisms visibly. However, such UV-B doses impair the development, motility and photoorientation of these organisms. Due to the inhibition of these physiological important parameters the organisms cannot respond adequately to the changing factors in their environment, which prevents the survival of the populations. (orig.) [de

  5. Endogenous Ion Dynamics in Cell Motility and Tissue Regeneration

    International Nuclear Information System (INIS)

    Özkucur, N; Perike, S; Epperlein, H H; Funk, R H W

    2011-01-01

    Directional cell migration is an essential process, including regeneration of tissues, wound healing, and embryonic development. Cells achieve persistent directional migration by polarizing the spatiotemporal components involved in the morphological polarity. Ion transporter proteins situated at the cell membrane generates small electric fields that can induce directional cell motility. Besides them, externally applied direct current electric fields induce similar kind of responses as cell orientation and directional migration. However, the bioelectric mechanisms that lead to cellular directedness are poorly understood. Therefore, understanding the bioelectric signaling cues can serve as a powerful modality in controlling the cell behaviour, which can contribute additional insights for development and regeneration.

  6. Identification and regulation of a molecular module for bleb-based cell motility

    NARCIS (Netherlands)

    Goudarzi, M.; Banisch, T.U.; Mobin, M.B.; Maghelli, N.; Tarbashevich, K.; Strate, I.; ter Berg, J.; Blaser, H.; Bandemer, S.; Paluch, E.; Bakkers, J.; Tolic-Norrelykke, I.M.; Raz, E.

    2012-01-01

    Single-cell migration is a key process in development, homeostasis, and disease. Nevertheless, the control over basic cellular mechanisms directing cells into motile behavior in vivo is largely unknown. Here, we report on the identification of a minimal set of parameters the regulation of which

  7. High-resolution esophageal pressure topography for esophageal motility disorders

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    Hashem Fakhre Yaseri

    2016-04-01

    Full Text Available Background: High-resolution manometer (HRM of the esophagus has become the main diagnostic test in the evaluation of esophageal motility disorders. The development of high-resolution manometry catheters and software displays of manometry recordings in color-coded pressure plots have changed the diagnostic assessment of esophageal disease. The first step of the Chicago classification described abnormal esophagogastric junction deglutitive relaxation. The latest classification system, proposed by Pandolfino et al, includes contraction patterns and peristalsis integrity based on integrated relaxation pressure 4 (IRP4. It can be discriminating the achalasia from non-achalasia esophageal motility disorders. The aim of this study was to assessment of clinical findings in non-achalasia esophageal motility disorders based on the most recent Chicago classification. Methods: We conducted a prospective cross-sectional study of 963 patients that had been referred to manometry department of Gastrointestinal and Liver Research Center, Firozgar Hospital, Tehran, Iran, from April, 2012 to April, 2015. They had upper GI disorder (Dysphasia, non-cardiac chest pain, regurgitation, heartburn, vomiting and asthma and weight loss. Data were collected from clinical examinations as well as patient questionnaires. Manometry, water-perfused, was done for all patients. Manometry criteria of the patients who had integrated relaxation pressure 4 (IRP4 ≤ 15 mmHg were studied. Results: Our finding showed that the non-achalasia esophageal motility disorders (58% was more common than the achalasia (18.2%. Heartburn (68.5%, regurgitation (65.4% and non-cardiac chest pain (60.6% were the most common clinical symptoms. Although, vomiting (91.7% and weight loss (63% were the most common symptoms in referring patients but did not discriminate this disorders from each other’s. Borderline motor function (67.2% was the most common, absent peristalsis (97% and the hyper

  8. Dual-function radiation sensitizers and bioreductive drugs: factors affecting cellular uptake and sensitizing efficiency in analogues of RSU 1069

    International Nuclear Information System (INIS)

    Walling, J.; Stratford, I.J.; Adams, G.E.; Stephens, M.A.

    1988-01-01

    Alkyl aziridine analogues of the hypoxic cell radiosensitizer RSU 1069 have been synthesized and one, RB 7040, containing tetramethyl substituted aziridine, is a more efficient sensitizer in vitro than RSU 1069 (Ahmed et al., 1986). The extent to which variation in drug uptake can influence the sensitizing efficiency of RSU 1069 and its analogues has been investigated by determining cellular uptake as a function of pH of extracellular medium (pHsub(e)) over the range 5.4-8.4. Following exposure of V79 cells for 1 h at room temperature, the ratio of intra-to extracellular concentration (Ci/Ce) was near unity at pH 5.4. Increasing pHsub(e) to 8.4 resulted in no change in the ratio Ci/Ce for RSU 1069 (pKsub(a) = 6.04). Values of Ci/Ce increased three-fold for RSU 1165 (pKsub(a) 7.38) and eleven-fold for RB 7040 (pKsub(a) = 8.45). Radiosensitization by RSU 1069 showed little dependence on pHsub(e) whereas increasing pH caused an apparent increase in sensitizing efficiency of both RSU 1165 and RB 7040. When enhancement ratios for sensitization were normalized to take account of the effect of extracellular pH on drug uptake, efficiency of sensitization was independent of pHsub(e). (author)

  9. Gene expression in Pseudomonas aeruginosa swarming motility

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    Déziel Eric

    2010-10-01

    Full Text Available Abstract Background The bacterium Pseudomonas aeruginosa is capable of three types of motilities: swimming, twitching and swarming. The latter is characterized by a fast and coordinated group movement over a semi-solid surface resulting from intercellular interactions and morphological differentiation. A striking feature of swarming motility is the complex fractal-like patterns displayed by migrating bacteria while they move away from their inoculation point. This type of group behaviour is still poorly understood and its characterization provides important information on bacterial structured communities such as biofilms. Using GeneChip® Affymetrix microarrays, we obtained the transcriptomic profiles of both bacterial populations located at the tip of migrating tendrils and swarm center of swarming colonies and compared these profiles to that of a bacterial control population grown on the same media but solidified to not allow swarming motility. Results Microarray raw data were corrected for background noise with the RMA algorithm and quantile normalized. Differentially expressed genes between the three conditions were selected using a threshold of 1.5 log2-fold, which gave a total of 378 selected genes (6.3% of the predicted open reading frames of strain PA14. Major shifts in gene expression patterns are observed in each growth conditions, highlighting the presence of distinct bacterial subpopulations within a swarming colony (tendril tips vs. swarm center. Unexpectedly, microarrays expression data reveal that a minority of genes are up-regulated in tendril tip populations. Among them, we found energy metabolism, ribosomal protein and transport of small molecules related genes. On the other hand, many well-known virulence factors genes were globally repressed in tendril tip cells. Swarm center cells are distinct and appear to be under oxidative and copper stress responses. Conclusions Results reported in this study show that, as opposed to

  10. A Single Argonaute Gene Participates in Exogenous and Endogenous RNAi and Controls Cellular Functions in the Basal Fungus Mucor circinelloides

    Science.gov (United States)

    Nicolás, Francisco E.; Moxon, Simon; de Haro, Juan P.; Dalmay, Tamas; Torres-Martínez, Santiago; Ruiz-Vázquez, Rosa M

    2013-01-01

    The mechanism of RNAi is well described in metazoans where it plays a role in diverse cellular functions. However, although different classes of endogenous small RNAs (esRNAs) have been identified in fungi, their biological roles are poorly described due, in part, to the lack of phenotype of mutants affected in the biogenesis of these esRNAs. Argonaute proteins are one of the key components of the RNAi pathways, in which different members of this protein family participate in the biogenesis of a wide repertoire of esRNAs molecules. Here we identified three argonaute genes of the fungus Mucor circinelloides and investigated their participation in exogenous and endogenous RNAi. We found that only one of the ago genes, ago-1, is involved in RNAi during vegetative growth and is required for both transgene-induced RNA silencing and the accumulation of distinct classes of esRNAs derived from exons (ex-siRNAs). Classes I and II ex-siRNAs bind to Ago-1 to control mRNA accumulation of the target protein coding genes. Class III ex-siRNAs do not specifically bind to Ago-1, but requires this protein for their production, revealing the complexity of the biogenesis pathways of ex-siRNAs. We also show that ago-1 is involved in the response to environmental signals, since vegetative development and autolysis induced by nutritional stress are affected in ago-1 − M. circinelloides mutants. Our results demonstrate that a single Ago protein participates in the production of different classes of esRNAs that are generated through different pathways. They also highlight the role of ex-siRNAs in the regulation of endogenous genes in fungi and expand the range of biological functions modulated by RNAi. PMID:23935973

  11. Effect of adenosine cyclophosphate combined with vitamin C on cellular immune function of children with viral myocarditis

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    Xiu Chang

    2016-06-01

    Full Text Available Objective: To investigate the curative effect of adenosine cyclophosphate combined with vitamin C on children with viral myocarditis andon cellular immune function. Methods: A total of 96 cases of children with viral myocarditis were randomly divided into control group and observation group, 48 cases in each. The control group received routine treatment for viral myocarditis. The observation group received routine treatment for viral myocarditis as well as vitamin C and adenosine cyclophosphate. Results: The total effective rate of observation group 89.59% was higher than that of control group 64.58%, and differences were statistical significant. The electrocardiogram total effective rate of observation group 91.67% was higher than that of control group 68.75%, and differences were statistical significant. After treatment, the level of CD3+ (65.09±10.35%, the level of CD4+ (42.93±6.22%, the level of CD8+ (29.55±4.87% and the level of NK (47.37±8.52% of observation group were higher than the level of CD3+ (51.85±9.33%, the level of CD4+ (35.18±5.73%, the level of CD8+ (24.46±4.03% and the level of NK (35.64±7.72% of control group, and differences were statistical significant. After treatment, myocardial enzyme indexes lactate dehydrogenase (329.65±19.76 U/L, creatine phosphate kinase (126.36±12.92 U/L, hydroxybutyrate dehydrogenase (271.68±14.73 U/L, glutamic oxaloacetic transaminase (31.22±3.76 U/ L and creatine kinase (185.28±13.83 U/L of observation group were lower than lactate dehydrogenase (348.06±20.51 U/L, creatine phosphate kinase (163.19±13.15 U/L, hydroxybutyrate dehydrogenase (305.50±16.42 U/L, glutamic oxaloacetic transaminase (37.87±4.07 U/L and creatine kinase (202.79±15.47 U/L of control group, and differences were statistical significant. After treatment, heart function indexes CI, FS and EF levels of observation group were higher than those of control group, and differences were statistical significant

  12. HES6 enhances the motility of alveolar rhabdomyosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Wickramasinghe, Caroline M [MRC Cancer Cell Unit, Hutchison-MRC Research centre, Addenbrooke' s Hospital Cambridge, CB2 0XZ (United Kingdom); MRC Laboratory of Molecular Biology, Addenbrooke' s Hospital Cambridge, CB2 0QH (United Kingdom); Domaschenz, Renae [MRC Cancer Cell Unit, Hutchison-MRC Research centre, Addenbrooke' s Hospital Cambridge, CB2 0XZ (United Kingdom); Gene Regulation and Chromatin Group, MRC Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Campus, Du Cane Road, London W12 ONN (United Kingdom); Amagase, Yoko [MRC Cancer Cell Unit, Hutchison-MRC Research centre, Addenbrooke' s Hospital Cambridge, CB2 0XZ (United Kingdom); Department of Pathophysiology, Faculty of Pharmaceutical Sciences, Doshisha Women' s College of Liberal Arts, Kodo, Kyotanabe, Kyoto 610-0395 (Japan); Williamson, Daniel [Molecular Cytogenetics, The Institute of Cancer Research, Sutton SM2 5NG (United Kingdom); Northern Institute for Cancer Research, Paul O' Gorman Building, Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH (United Kingdom); Missiaglia, Edoardo; Shipley, Janet [Molecular Cytogenetics, The Institute of Cancer Research, Sutton SM2 5NG (United Kingdom); Murai, Kasumi [MRC Cancer Cell Unit, Hutchison-MRC Research centre, Addenbrooke' s Hospital Cambridge, CB2 0XZ (United Kingdom); Jones, Philip H, E-mail: phj20@cam.ac.uk [MRC Cancer Cell Unit, Hutchison-MRC Research centre, Addenbrooke' s Hospital Cambridge, CB2 0XZ (United Kingdom)

    2013-01-01

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

  13. Long-time tails of the velocity autocorrelation function in 2D and 3D lattice gas cellular automata: a test of mode-coupling theory

    NARCIS (Netherlands)

    Hoef, M.A. van der; Frenkel, D.

    1990-01-01

    We report simulations of the velocity autocorrelation function (VACF) of a tagged particle in two- and three-dimensional lattice-gas cellular automata, using a new technique that is about a million times more efficient than the conventional techniques. The simulations clearly show the algebraic

  14. Reconfigurable engineered motile semiconductor microparticles.

    Science.gov (United States)

    Ohiri, Ugonna; Shields, C Wyatt; Han, Koohee; Tyler, Talmage; Velev, Orlin D; Jokerst, Nan

    2018-05-03

    Locally energized particles form the basis for emerging classes of active matter. The design of active particles has led to their controlled locomotion and assembly. The next generation of particles should demonstrate robust control over their active assembly, disassembly, and reconfiguration. Here we introduce a class of semiconductor microparticles that can be comprehensively designed (in size, shape, electric polarizability, and patterned coatings) using standard microfabrication tools. These custom silicon particles draw energy from external electric fields to actively propel, while interacting hydrodynamically, and sequentially assemble and disassemble on demand. We show that a number of electrokinetic effects, such as dielectrophoresis, induced charge electrophoresis, and diode propulsion, can selectively power the microparticle motions and interactions. The ability to achieve on-demand locomotion, tractable fluid flows, synchronized motility, and reversible assembly using engineered silicon microparticles may enable advanced applications that include remotely powered microsensors, artificial muscles, reconfigurable neural networks and computational systems.

  15. Scintigraphic assessment of gastrointestinal motility

    DEFF Research Database (Denmark)

    Madsen, Jan Lysgård

    2014-01-01

    intestinal and colonic transit. This article reviews current imaging techniques, methods for data processing and principles for evaluating results when scintigraphy is used to assess gastrointestinal motility. Furthermore, clinical indications for performing scintigraphy are reviewed.......Gastrointestinal transit reflects overall gastrointestinal motor activity and is regulated by a complex interplay between neural and hormonal stimuli. Thus, transit measurements provide a measure of the combined effects of gastrointestinal muscular activity and feedback from the gut and brain....... Dysmotility in the different major segments of the gastrointestinal tract may give rise to similar symptoms; hence, localizing transit abnormalities to a specific segment is a valuable element of diagnostic evaluation. Scintigraphy is an effective noninvasive tool to assess gastric emptying as well as small...

  16. Telmisartan enhances mitochondrial activity and alters cellular functions in human coronary artery endothelial cells via AMP-activated protein kinase pathway.

    Science.gov (United States)

    Kurokawa, Hirofumi; Sugiyama, Seigo; Nozaki, Toshimitsu; Sugamura, Koichi; Toyama, Kensuke; Matsubara, Junichi; Fujisue, Koichiro; Ohba, Keisuke; Maeda, Hirofumi; Konishi, Masaaki; Akiyama, Eiichi; Sumida, Hitoshi; Izumiya, Yasuhiro; Yasuda, Osamu; Kim-Mitsuyama, Shokei; Ogawa, Hisao

    2015-04-01

    Mitochondrial dysfunction plays an important role in cellular senescence and impaired function of vascular endothelium, resulted in cardiovascular diseases. Telmisartan is a unique angiotensin II type I receptor blocker that has been shown to prevent cardiovascular events in high risk patients. AMP-activated protein kinase (AMPK) plays a critical role in mitochondrial biogenesis and endothelial function. This study assessed whether telmisartan enhances mitochondrial function and alters cellular functions via AMPK in human coronary artery endothelial cells (HCAECs). In cultured HCAECs, telmisartan significantly enhanced mitochondrial activity assessed by mitochondrial reductase activity and intracellular ATP production and increased the expression of mitochondria related genes. Telmisartan prevented cellular senescence and exhibited the anti-apoptotic and pro-angiogenic properties. The expression of genes related anti-oxidant and pro-angiogenic properties were increased by telmisartan. Telmisartan increased endothelial NO synthase and AMPK phosphorylation. Peroxisome proliferator-activated receptor gamma signaling was not involved in telmisartan-induced improvement of mitochondrial function. All of these effects were abolished by inhibition of AMPK. Telmisartan enhanced mitochondrial activity and exhibited anti-senescence effects and improving endothelial function through AMPK in HCAECs. Telmisartan could provide beneficial effects on vascular diseases via enhancement of mitochondrial activity and modulating endothelial function through AMPK activation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Plexin-B2 negatively regulates macrophage motility, Rac, and Cdc42 activation.

    Directory of Open Access Journals (Sweden)

    Kelly E Roney

    Full Text Available Plexins are cell surface receptors widely studied in the nervous system, where they mediate migration and morphogenesis though the Rho family of small GTPases. More recently, plexins have been implicated in immune processes including cell-cell interaction, immune activation, migration, and cytokine production. Plexin-B2 facilitates ligand induced cell guidance and migration in the nervous system, and induces cytoskeletal changes in overexpression assays through RhoGTPase. The function of Plexin-B2 in the immune system is unknown. This report shows that Plexin-B2 is highly expressed on cells of the innate immune system in the mouse, including macrophages, conventional dendritic cells, and plasmacytoid dendritic cells. However, Plexin-B2 does not appear to regulate the production of proinflammatory cytokines, phagocytosis of a variety of targets, or directional migration towards chemoattractants or extracellular matrix in mouse macrophages. Instead, Plxnb2(-/- macrophages have greater cellular motility than wild type in the unstimulated state that is accompanied by more active, GTP-bound Rac and Cdc42. Additionally, Plxnb2(-/- macrophages demonstrate faster in vitro wound closure activity. Studies have shown that a closely related family member, Plexin-B1, binds to active Rac and sequesters it from downstream signaling. The interaction of Plexin-B2 with Rac has only been previously confirmed in yeast and bacterial overexpression assays. The data presented here show that Plexin-B2 functions in mouse macrophages as a negative regulator of the GTPases Rac and Cdc42 and as a negative regulator of basal cell motility and wound healing.

  18. Functional interactions of nucleocapsid protein of feline immunodeficiency virus and cellular prion protein with the viral RNA.

    Science.gov (United States)

    Moscardini, Mila; Pistello, Mauro; Bendinelli, M; Ficheux, Damien; Miller, Jennifer T; Gabus, Caroline; Le Grice, Stuart F J; Surewicz, Witold K; Darlix, Jean-Luc

    2002-04-19

    All lentiviruses and oncoretroviruses examined so far encode a major nucleic-acid binding protein (nucleocapsid or NC* protein), approximately 2500 molecules of which coat the dimeric RNA genome. Studies on HIV-1 and MoMuLV using in vitro model systems and in vivo have shown that NC protein is required to chaperone viral RNA dimerization and packaging during virus assembly, and proviral DNA synthesis by reverse transcriptase (RT) during infection. The human cellular prion protein (PrP), thought to be the major component of the agent causing transmissible spongiform encephalopathies (TSE), was recently found to possess a strong affinity for nucleic acids and to exhibit chaperone properties very similar to HIV-1 NC protein in the HIV-1 context in vitro. Tight binding of PrP to nucleic acids is proposed to participate directly in the prion disease process. To extend our understanding of lentiviruses and of the unexpected nucleic acid chaperone properties of the human prion protein, we set up an in vitro system to investigate replication of the feline immunodeficiency virus (FIV), which is functionally and phylogenetically distant from HIV-1. The results show that in the FIV model system, NC protein chaperones viral RNA dimerization, primer tRNA(Lys,3) annealing to the genomic primer-binding site (PBS) and minus strand DNA synthesis by the homologous FIV RT. FIV NC protein is able to trigger specific viral DNA synthesis by inhibiting self-priming of reverse transcription. The human prion protein was found to mimic the properties of FIV NC with respect to primer tRNA annealing to the viral RNA and chaperoning minus strand DNA synthesis. Copyright 2002 Elsevier Science Ltd.

  19. Enrichment from birth accelerates the functional and cellular development of a motor control area in the mouse.

    Directory of Open Access Journals (Sweden)

    Teresa Simonetti

    Full Text Available BACKGROUND: There is strong evidence that sensory experience in early life has a profound influence on the development of sensory circuits. Very little is known, however, about the role of experience in the early development of striatal networks which regulate both motor and cognitive function. To address this, we have investigated the influence of early environmental enrichment on motor development. METHODOLOGY/PRINCIPAL FINDINGS: Mice were raised in standard or enriched housing from birth. For animals assessed as adults, half of the mice had their rearing condition reversed at weaning to enable the examination of the effects of pre- versus post-weaning enrichment. We found that exclusively pre-weaning enrichment significantly improved performance on the Morris water maze compared to non-enriched mice. The effects of early enrichment on the emergence of motor programs were assessed by performing behavioural tests at postnatal day 10. Enriched mice traversed a significantly larger region of the test arena in an open-field test and had improved swimming ability compared to non-enriched cohorts. A potential cellular correlate of these changes was investigated using Wisteria-floribunda agglutinin (WFA staining to mark chondroitin-sulfate proteoglycans (CSPGs. We found that the previously reported transition of CSPG staining from striosome-associated clouds to matrix-associated perineuronal nets (PNNs is accelerated in enriched mice. CONCLUSIONS/SIGNIFICANCE: This is the first demonstration that the early emergence of exploratory as well as coordinated movement is sensitive to experience. These behavioural changes are correlated with an acceleration of the emergence of striatal PNNs suggesting that they may consolidate the neural circuits underlying these behaviours. Finally, we confirm that pre-weaning experience can lead to life long changes in the learning ability of mice.

  20. Esophageal Motility Disorders: Current Concepts of Pathogenesis and Treatment

    Directory of Open Access Journals (Sweden)

    Peter J Kahrilas

    2000-01-01

    Full Text Available Current concepts of esophageal motility disorders are summarized. Primary data sources were located via MEDLINE or cross-citation. No attempt was made to be comprehensive or inclusive of the literature because fewer than 10% of citations are discussed. Instead, emphasis was placed on new developments in diagnosis, therapeutics, and practice patterns. Controlled therapeutic trials and pathophysiological observations are emphasized. Achalasia is a rare disease of failed lower sphincter relaxation and aperistalsis. Diffuse esophageal spasm (DES, an equally rare disease, is defined by non-propagated esophageal contractions. Nonspecific motility disorders, including nutcracker esophagus and hypertensive lower esophageal sphincter, are identified only by manometry and are ten times as prevalent. Neuromuscular pathology is evident only with achalasia (myenteric plexus neurons destruction. Pharmacological therapies have limited efficacy with achalasia; more limited with DES; and none with the nonspecific motility disorders. More efficacious therapies for the nonspecific disorders are directed at associated reflux disease or psychiatric disorders. Pneumatic dilation is effective therapy for achalasia 72% of instances, but frequently requires repeat dilation and is complicated by a 3% perforation rate. Surgical myotomy is effective in 88% of achalasics; morbidity from thoracotomy has been the major limitation but this has been sharply reduced with a laparoscopic approach. In conclusion, although it has been suggested that esophageal motility disorders are distinct clinical entities, critical review of the literature supports this only in the case of achalasia, a disease of well defined pathophysiology, functional disturbance, and therapies. This clarity diminishes progressively for DES and non-specific esophageal motility disorders.

  1. Polymyxin B effects on motility parameters of cryopreserved bull semen

    Directory of Open Access Journals (Sweden)

    Mojtaba Rashedi

    2017-01-01

    Full Text Available Objective: To evaluate the effect of adding different values of polymyxin B (PMB to bull semen on various motility parameters of post-thawed semen such as total motility, progressive motility and velocity parameters using kinetic parameters of sperm by Computer Assisted Sperm Analysis.Methods: Gram negative bacteria release lipopolysaccharide, which induces the apoptotic pathway. Antibiotics are added to semen in order to prevent bacterial contaminations in bovine semen. These antibiotics kill the bacteria especially gram negative bacteria. Therefore, their endotoxins are released during bacteriolysis and bind to the head region and midpiece of sperm. PMB is a bactericidal antibiotic against multidrug resistant gram-negative bacteria and is able to neutralize the toxic effects of the released endotoxin. This study was performed on 3-year old Taleshi bulls.Results: The results showed both positive and negative significant effects of PMB on semen quality. Total motility and progressive motility were significantly increased (P<0.000 1 by 100 μg per mL of PMB (55.2% and 48.8% respectively against the control groups (43.5% and 37.7%, respectively. Moreover, they were significantly decreased (P<0.000 1 by 1 000 μg per mL of PMB (35.2% and 28.8% respectively against the control groups (43.5% and 37.7% respectively in above-mentioned parameters. In Computer Assisted Semen Analyzer, parameter VAP was significantly decreased (P<0.04 in 1 000 μg (69.6 μm/s against the control group (78.7 μm/s. Finally, using PMB in processing cryopreserved bull semen is advised, but before using it, the rate of endotoxins must be measured.Conclusions: We advise using PMB after measuring endotoxin concentration; In vitro, in vivo and in field fertilization, adding other sperm evaluation factors such as acrosomal integrity, DNA integrity, mitochondrial function to PMB treated semen.

  2. Scintigraphic evaluation of gastric emptying and motility

    International Nuclear Information System (INIS)

    Linke, R.

    2003-01-01

    The stomach consists of two functionally distinct parts. The fundus and upper corpus mainly serve as a reservoir and exert primarily a tonic activity, which presses ingesta towards the antrum and duodenum. The phasic contractility of the lower corpus and antrum cause mechanical breakdown and mixing of the food particels. A complex regulation of these mechanisms provides a regular gastric emptying. Various disorders such as diabetes mellitus, mixed connective tissue diseases, gastritis, tumors, dyspeptic disorders but also drugs and gastric surgery may influence or impair gastric function and may cause typical symptoms such as upper abdominal discomfort, bloating, nausea and vomiting. However, the interpretation of gastrointestinal symptoms often is difficult. Radionuclide studies of gastric emptying and motility are the most physiologic tools available for studying gastric motor function. Gastric scintigraphy is non-invasive, uses physiologic meal and is quantitative. Emptying curves generated from the gastric ROI offer information whether a disorder is accompanied by a regular, fast or slow gastric emptying. Data on gastric contractions (amplitude and frequency) provide additional information to results obtained by conventional emptying studies. Depending on the underlying disorder, gastric emptying and peristalsis showed both corresponding and discrepant findings. Therefore, both parameters should be routinely assessed to further improve characterisation of gastric dysfunction by scintigraphy. (orig.) [de

  3. Effects of electromagnetic interference on the functional usage of medical equipment by 2G/3G/4G cellular phones: A revie

    Directory of Open Access Journals (Sweden)

    Periyasamy M. Mariappan

    2016-09-01

    Full Text Available There has been an increase in the potential use of wireless devices in healthcare domain for a variety of reasons. The most commonly used device is the cellular phone, which emits strong electromagnetic energy affecting thereby the functionality of the vital medical equipment such as ventilators, ECG monitors, cardiac monitors, and defibrillators. This prompted the healthcare concerns to restrict the use of these phones in the proximity of critical and non-critical care medical equipment. Due to the developments made in the design of medical equipment to comply with the EMC standards, the restriction had been slowly laid off. Still, the researchers are concerned about the electromagnetic interference with medical devices by cellular phones in the healthcare domain and recommend for conducting continuous research to study their interaction with medical equipment. This paper overviews the certain investigations carried out in the recent years to study the electromagnetic interference between medical devices and 2G/3G/4G LTE cellular phones. During the initial development of cellular phones, the 2G cellular phones had caused more interference that affects the function and operation of some medical devices. The possibility of interference from 3G cellular phones with medical devices was considerably lower than the 2G phones, but still exists. Furthermore, almost all of the 4G phones have little to no interference with the medical devices. Currently, with the development of the medical devices industry, the current medical devices are designed to operate safely under any conditions of usage. Finally, a careful analysis would require statistics on the frequency of adverse events across the healthcare system, which apparently do not exist.

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

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  5. Barriers to bacterial motility on unsaturated surfaces

    DEFF Research Database (Denmark)

    Dechesne, Arnaud; Smets, Barth F.

    2013-01-01

    Our knowledge of the spatial organization and spatial dynamics of microbial populations in soil at a scale close to that of the microorganisms is scarce. While passive dispersal via water ow or soil biota is probably a major dispersal route, it is reasonable to consider that active dispersal also...... and their isogenic mutants unable to express various type of motility we aimed to quantify the physical limits of bacterial motility. Our results demonstrate how hydration controls bacterial motility under unsaturated conditions. They can form the base of improved biodegradation models that include microbial...

  6. Plankton motility patterns and encounter rates

    DEFF Research Database (Denmark)

    Visser, Andre; Kiørboe, Thomas

    2006-01-01

    measure of run length to reaction distance determines whether the underlying encounter is ballistic or diffusive. Since ballistic interactions are intrinsically more efficient than diffusive, we predict that organisms will display motility with long correlation run lengths compared to their reaction...... distances to their prey, but short compared to the reaction distances of their predators. We show motility data for planktonic organisms ranging from bacteria to copepods that support this prediction. We also present simple ballistic and diffusive motility models for estimating encounter rates, which lead...

  7. Cellular gravity

    NARCIS (Netherlands)

    F.C. Gruau; J.T. Tromp (John)

    1999-01-01

    textabstractWe consider the problem of establishing gravity in cellular automata. In particular, when cellular automata states can be partitioned into empty, particle, and wall types, with the latter enclosing rectangular areas, we desire rules that will make the particles fall down and pile up on

  8. Intracellular Localization and Cellular Factors Interaction of HTLV-1 and HTLV-2 Tax Proteins: Similarities and Functional Differences

    Directory of Open Access Journals (Sweden)

    Maria Grazia Romanelli

    2011-05-01

    Full Text Available Human T-lymphotropic viruses type 1 (HTLV-1 and type 2 (HTLV-2 present very similar genomic structures but HTLV-1 is more pathogenic than HTLV-2. Is this difference due to their transactivating Tax proteins, Tax-1 and Tax-2, which are responsible for viral and cellular gene activation? Do Tax-1 and Tax-2 differ in their cellular localization and in their interaction pattern with cellular factors? In this review, we summarize Tax-1 and Tax-2 structural and phenotypic properties, their interaction with factors involved in signal transduction and their localization-related behavior within the cell. Special attention will be given to the distinctions between Tax-1 and Tax-2 that likely play an important role in their transactivation activity.

  9. Physiology of Normal Esophageal Motility

    Science.gov (United States)

    Goyal, Raj K; Chaudhury, Arun

    2009-01-01

    The esophagus consists of two different parts. In humans, the cervical esophagus is composed of striated muscles and the thoracic esophagus is composed of phasic smooth muscles. The striated muscle esophagus is innervated by the lower motor neurons and peristalsis in this segment is due to sequential activation of the motor neurons in the nucleus ambiguus. Both primary and secondary peristaltic contractions are centrally mediated. The smooth muscle of esophagus is phasic in nature and is innervated by intramural inhibitory (nitric oxide releasing) and excitatory (acetylcholine releasing) neurons that receive inputs from separate sets of preganglionic neurons located in the dorsal motor nucleus of vagus. The primary peristalsis in this segment involves both central and peripheral mechanisms. The primary peristalsis consist of inhibition (called deglutitive inhibition) followed by excitation. The secondary peristalsis is entirely due to peripheral mechanisms and also involves inhibition followed by excitation. The lower esophageal sphincter (LES) is characterized by tonic muscle that is different from the muscle of the esophageal body. The LES, like the esophageal body smooth muscle, is also innervated by the inhibitory and excitatory neurons. The LES maintains tonic closure due to its myogenic property. The LES tone is modulated by the inhibitory and the excitatory nerves. Inhibitory nerves mediate LES relaxation and the excitatory nerves mediate reflex contraction or rebound contraction of the LES. Clinical disorders of esophageal motility can be classified on the basis of disorders of the inhibitory and excitatory innervations and the smooth muscles. PMID:18364578

  10. HEATR2 plays a conserved role in assembly of the ciliary motile apparatus.

    Directory of Open Access Journals (Sweden)

    Christine P Diggle

    2014-09-01

    Full Text Available Cilia are highly conserved microtubule-based structures that perform a variety of sensory and motility functions during development and adult homeostasis. In humans, defects specifically affecting motile cilia lead to chronic airway infections, infertility and laterality defects in the genetically heterogeneous disorder Primary Ciliary Dyskinesia (PCD. Using the comparatively simple Drosophila system, in which mechanosensory neurons possess modified motile cilia, we employed a recently elucidated cilia transcriptional RFX-FOX code to identify novel PCD candidate genes. Here, we report characterization of CG31320/HEATR2, which plays a conserved critical role in forming the axonemal dynein arms required for ciliary motility in both flies and humans. Inner and outer arm dyneins are absent from axonemes of CG31320 mutant flies and from PCD individuals with a novel splice-acceptor HEATR2 mutation. Functional conservation of closely arranged RFX-FOX binding sites upstream of HEATR2 orthologues may drive higher cytoplasmic expression of HEATR2 during early motile ciliogenesis. Immunoprecipitation reveals HEATR2 interacts with DNAI2, but not HSP70 or HSP90, distinguishing it from the client/chaperone functions described for other cytoplasmic proteins required for dynein arm assembly such as DNAAF1-4. These data implicate CG31320/HEATR2 in a growing intracellular pre-assembly and transport network that is necessary to deliver functional dynein machinery to the ciliary compartment for integration into the motile axoneme.

  11. Bacterial spread from cell to cell: beyond actin-based motility.

    Science.gov (United States)

    Kuehl, Carole J; Dragoi, Ana-Maria; Talman, Arthur; Agaisse, Hervé

    2015-09-01

    Several intracellular pathogens display the ability to propagate within host tissues by displaying actin-based motility in the cytosol of infected cells. As motile bacteria reach cell-cell contacts they form plasma membrane protrusions that project into adjacent cells and resolve into vacuoles from which the pathogen escapes, thereby achieving spread from cell to cell. Seminal studies have defined the bacterial and cellular factors that support actin-based motility. By contrast, the mechanisms supporting the formation of protrusions and their resolution into vacuoles have remained elusive. Here, we review recent advances in the field showing that Listeria monocytogenes and Shigella flexneri have evolved pathogen-specific mechanisms of bacterial spread from cell to cell. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Sorbitol Can Fuel Mouse Sperm Motility and Protein Tyrosine Phosphorylation via Sorbitol Dehydrogenase1

    OpenAIRE

    Cao, Wenlei; Aghajanian, Haig K.; Haig-Ladewig, Lisa A.; Gerton, George L.

    2009-01-01

    Energy sources that can be metabolized to yield ATP are essential for normal sperm functions such as motility. Two major monosaccharides, sorbitol and fructose, are present in semen. Furthermore, sorbitol dehydrogenase (SORD) can convert sorbitol to fructose, which can then be metabolized via the glycolytic pathway in sperm to make ATP. Here we characterize Sord mRNA and SORD expression during mouse spermatogenesis and examine the ability of sorbitol to support epididymal sperm motility and t...

  13. MTSS1 is epigenetically regulated in glioma cells and inhibits glioma cell motility

    Directory of Open Access Journals (Sweden)

    Daniel Luxen

    2017-02-01

    Full Text Available Epigenetic silencing by DNA methylation in brain tumors has been reported for many genes, however, their function on pathogenesis needs to be evaluated. We investigated the MTSS1 gene, identified as hypermethylated by differential methylation hybridization (DMH. Fifty-nine glioma tissue samples and seven glioma cell lines were examined for hypermethylation of the MTSS1 promotor, MTSS1 expression levels and gene dosage. GBM cell lines were treated with demethylating agents and interrogated for functional consequences of MTSS1 expression after transient transfection. Hypermethylation was significantly associated with IDH1/2 mutation. Comparative SNP analysis indicates higher incidence of loss of heterozygosity of MTSS1 in anaplastic astrocytomas and secondary glioblastomas as well as hypermethylation of the remaining allele. Reversal of promoter hypermethylation results in an increased MTSS1 expression. Cell motility was significantly inhibited by MTSS1 overexpression without influencing cell growth or apoptosis. Immunofluorescence analysis of MTSS1 in human astrocytes indicates co-localization with actin filaments. MTSS1 is down-regulated by DNA methylation in glioblastoma cell lines and is part of the G-CIMP phenotype in primary glioma tissues. Our data on normal astrocytes suggest a function of MTSS1 at focal contact structures with an impact on migratory capacity but no influence on apoptosis or cellular proliferation.

  14. Chlorpyrifos, chlorpyrifos-oxon, and diisopropylfluorophosphate inhibit kinesin-dependent microtubule motility

    International Nuclear Information System (INIS)

    Gearhart, Debra A.; Sickles, Dale W.; Buccafusco, Jerry J.; Prendergast, Mark A.; Terry, Alvin V.

    2007-01-01

    Diisopropylfluorophosphate, originally developed as a chemical warfare agent, is structurally similar to nerve agents, and chlorpyrifos has extensive worldwide use as an agricultural pesticide. While inhibition of cholinesterases underlies the acute toxicity of these organophosphates, we previously reported impaired axonal transport in the sciatic nerves from rats treated chronically with subthreshold doses of chlorpyrifos. Those data indicate that chlorpyrifos (and/or its active metabolite, chlorpyrifos-oxon) might directly affect the function of kinesin and/or microtubules-the principal proteins that mediate anterograde axonal transport. The current report describes in vitro assays to assess the concentration-dependent effects of chlorpyrifos (0-10 μM), chlorpyrifos-oxon (0-10 μM), and diisopropylfluorophosphate (0-0.59 nM) on kinesin-dependent microtubule motility. Preincubating bovine brain microtubules with the organophosphates did not alter kinesin-mediated microtubule motility. In contrast, preincubation of bovine brain kinesin with diisopropylfluorophosphate, chlorpyrifos, or chlorpyrifos-oxon produced a concentration-dependent increase in the number of locomoting microtubules that detached from the kinesin-coated glass cover slip. Our data suggest that the organophosphates-chlorpyrifos-oxon, chlorpyrifos, and diisopropylfluorophosphate-directly affect kinesin, thereby disrupting kinesin-dependent transport on microtubules. Kinesin-dependent movement of vesicles, organelles, and other cellular components along microtubules is fundamental to the organization of all eukaryotic cells, especially in neurons where organelles and proteins synthesized in the cell body must move down long axons to pre-synaptic sites in nerve terminals. We postulate that disruption of kinesin-dependent intracellular transport could account for some of the long-term effects of organophosphates on the peripheral and central nervous system

  15. Mammalian Sperm Motility: Observation and Theory

    KAUST Repository

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

    2011-01-01

    the mechanics of these specialized cells, especially during their remarkable journey to the egg. The biological structure of the motile sperm appendage, the flagellum, is described and placed in the context of the mechanics underlying the migration of mammalian

  16. Mammalian Sperm Motility: Observation and Theory

    KAUST Repository

    Gaffney, E.A.

    2011-01-21

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

  17. Functional Comparison of Bacteria from the Human Gut and Closely Related Non-Gut Bacteria Reveals the Importance of Conjugation and a Paucity of Motility and Chemotaxis Functions in the Gut Environment.

    Science.gov (United States)

    Dobrijevic, Dragana; Abraham, Anne-Laure; Jamet, Alexandre; Maguin, Emmanuelle; van de Guchte, Maarten

    2016-01-01

    The human GI tract is a complex and still poorly understood environment, inhabited by one of the densest microbial communities on earth. The gut microbiota is shaped by millennia of evolution to co-exist with the host in commensal or symbiotic relationships. Members of the gut microbiota perform specific molecular functions important in the human gut environment. This can be illustrated by the presence of a highly expanded repertoire of proteins involved in carbohydrate metabolism, in phase with the large diversity of polysaccharides originating from the diet or from the host itself that can be encountered in this environment. In order to identify other bacterial functions that are important in the human gut environment, we investigated the distribution of functional groups of proteins in a group of human gut bacteria and their close non-gut relatives. Complementary to earlier global comparisons between different ecosystems, this approach should allow a closer focus on a group of functions directly related to the gut environment while avoiding functions related to taxonomically divergent microbiota composition, which may or may not be relevant for gut homeostasis. We identified several functions that are overrepresented in the human gut bacteria which had not been recognized in a global approach. The observed under-representation of certain other functions may be equally important for gut homeostasis. Together, these analyses provide us with new information about this environment so critical to our health and well-being.

  18. Functional Comparison of Bacteria from the Human Gut and Closely Related Non-Gut Bacteria Reveals the Importance of Conjugation and a Paucity of Motility and Chemotaxis Functions in the Gut Environment.

    Directory of Open Access Journals (Sweden)

    Dragana Dobrijevic

    Full Text Available The human GI tract is a complex and still poorly understood environment, inhabited by one of the densest microbial communities on earth. The gut microbiota is shaped by millennia of evolution to co-exist with the host in commensal or symbiotic relationships. Members of the gut microbiota perform specific molecular functions important in the human gut environment. This can be illustrated by the presence of a highly expanded repertoire of proteins involved in carbohydrate metabolism, in phase with the large diversity of polysaccharides originating from the diet or from the host itself that can be encountered in this environment. In order to identify other bacterial functions that are important in the human gut environment, we investigated the distribution of functional groups of proteins in a group of human gut bacteria and their close non-gut relatives. Complementary to earlier global comparisons between different ecosystems, this approach should allow a closer focus on a group of functions directly related to the gut environment while avoiding functions related to taxonomically divergent microbiota composition, which may or may not be relevant for gut homeostasis. We identified several functions that are overrepresented in the human gut bacteria which had not been recognized in a global approach. The observed under-representation of certain other functions may be equally important for gut homeostasis. Together, these analyses provide us with new information about this environment so critical to our health and well-being.

  19. Estimate of oxygen consumption and intracellular zinc concentration of human spermatozoa in relation to motility.

    Science.gov (United States)

    Henkel, Ralf R; Defosse, Kerstin; Koyro, Hans-Wilhelm; Weissmann, Norbert; Schill, Wolf-Bernhard

    2003-03-01

    To investigate the human sperm oxygen/energy consumption and zinc content in relation to motility. In washed spermatozoa from 67 ejaculates, the oxygen consumption was determined. Following calculation of the total oxygen consumed by the Ideal Gas Law, the energy consumption of spermatozoa was calculated. In addition, the zinc content of the sperm was determined using an atomic absorption spectrometer. The resulting data were correlated to the vitality and motility. The oxygen consumption averaged 0.24 micromol/10(6) sperm x 24h, 0.28 micromol/10(6) live sperm x 24h and 0.85 micromol/10(6) live motile sperm x 24h. Further calculations revealed that sperm motility was the most energy consuming process (164.31 mJ/10(6) motile spermatozoa x 24h), while the oxygen consumption of the total spermatozoa was 46.06 mJ/10(6) spermatozoa x 24h. The correlation of the oxygen/energy consumption and zinc content with motility showed significant negative correlations (r= -0.759; P<0.0001 and r=-0.441; P<0.0001, respectively). However, when correlating sperm energy consumption with the zinc content, a significant positive relation (r=0.323; P=0.01) was observed. Poorly motile sperm are actually wasting the available energy. Moreover, our data clearly support the "Geometric Clutch Model" of the axoneme function and demonstrate the importance of the outer dense fibers for the generation of sperm motility, especially progressive motility.

  20. PLAG1 deficiency impairs spermatogenesis and sperm motility in mice.

    Science.gov (United States)

    Juma, Almas R; Grommen, Sylvia V H; O'Bryan, Moira K; O'Connor, Anne E; Merriner, D Jo; Hall, Nathan E; Doyle, Stephen R; Damdimopoulou, Pauliina E; Barriga, Daniel; Hart, Adam H; Van de Ven, Wim J M; De Groef, Bert

    2017-07-13

    Deficiency in pleomorphic adenoma gene 1 (PLAG1) leads to reduced fertility in male mice, but the mechanism by which PLAG1 contributes to reproduction is unknown. To investigate the involvement of PLAG1 in testicular function, we determined (i) the spatial distribution of PLAG1 in the testis using X-gal staining; (ii) transcriptomic consequences of PLAG1 deficiency in knock-out and heterozygous mice compared to wild-type mice using RNA-seq; and (iii) morphological and functional consequences of PLAG1 deficiency by determining testicular histology, daily sperm production and sperm motility in knock-out and wild-type mice. PLAG1 was sparsely expressed in germ cells and in Sertoli cells. Genes known to be involved in spermatogenesis were downregulated in the testes of knock-out mice, as well as Hsd17b3, which encodes a key enzyme in androgen biosynthesis. In the absence of Plag1, a number of genes involved in immune processes and epididymis-specific genes were upregulated in the testes. Finally, loss of PLAG1 resulted in significantly lowered daily sperm production, in reduced sperm motility, and in several animals, in sloughing of the germinal epithelium. Our results demonstrate that the subfertility seen in male PLAG1-deficient mice is, at least in part, the result of significantly reduced sperm output and sperm motility.

  1. Effect of psychological intervention in the form of relaxation and guided imagery on cellular immune function in normal healthy subjects. An overview

    DEFF Research Database (Denmark)

    Zachariae, R; Kristensen, J S; Hokland, P

    1991-01-01

    The present study measured the effects of relaxation and guided imagery on cellular immune function. During a period of 10 days 10 healthy subjects were given one 1-hour relaxation procedure and one combined relaxation and guided imagery procedure, instructing the subjects to imagine their immune...... on the immune defense and could form the basis of further studies on psychological intervention and immunological status. Udgivelsesdato: 1990-null...

  2. Azospirillum brasilense Chemotaxis Depends on Two Signaling Pathways Regulating Distinct Motility Parameters.

    Science.gov (United States)

    Mukherjee, Tanmoy; Kumar, Dhivya; Burriss, Nathan; Xie, Zhihong; Alexandre, Gladys

    2016-06-15

    The genomes of most motile bacteria encode two or more chemotaxis (Che) systems, but their functions have been characterized in only a few model systems. Azospirillum brasilense is a motile soil alphaproteobacterium able to colonize the rhizosphere of cereals. In response to an attractant, motile A. brasilense cells transiently increase swimming speed and suppress reversals. The Che1 chemotaxis pathway was previously shown to regulate changes in the swimming speed, but it has a minor role in chemotaxis and root surface colonization. Here, we show that a second chemotaxis system, named Che4, regulates the probability of swimming reversals and is the major signaling pathway for chemotaxis and wheat root surface colonization. Experimental evidence indicates that Che1 and Che4 are functionally linked to coordinate changes in the swimming motility pattern in response to attractants. The effect of Che1 on swimming speed is shown to enhance the aerotactic response of A. brasilense in gradients, likely providing the cells with a competitive advantage in the rhizosphere. Together, the results illustrate a novel mechanism by which motile bacteria utilize two chemotaxis pathways regulating distinct motility parameters to alter movement in gradients and enhance the chemotactic advantage. Chemotaxis provides motile bacteria with a competitive advantage in the colonization of diverse niches and is a function enriched in rhizosphere bacterial communities, with most species possessing at least two chemotaxis systems. Here, we identify the mechanism by which cells may derive a significant chemotactic advantage using two chemotaxis pathways that ultimately regulate distinct motility parameters. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. Condensed images for evaluating gastric motility patterns

    Energy Technology Data Exchange (ETDEWEB)

    Tatsch, K.; Schroettle, W.; Kirsch, C.-M. (Munich Univ. (Germany, F.R.). Dept. of Radiology)

    1991-04-01

    A condensed imaging technique was applied to gastric emptying studies to investigate (a) whether different types of motility disorders may be distinguished by characteristic image patterns and (b) whether the findings obtained provide additional information compared to standard quantitative measurements. Condensed images and quantitative data of gastric emptying were evaluated in 75 consecutive patients with normal function and various disorders such as peptic ulcer, postvagotomy, pyloric obstruction, dumping syndrome, gastoparesis etc. Condensed images were generated from a gastric region of interest. They display the distribution and behaviour of a radioactive test meal in a space-time matrix, whose horizontal and vertical dimensions are temporal and spatial, respectively. As shown in a series of representative examples condensed images disclose a variety of well-defined image patterns reflecting different pathophysiological mechanisms. This qualitative characterization of gastric emptying patterns provided in 34 of the 75 patients (45%) important new information compared to quantitative data. The application of condensed imaging techniques to gastric emptying studies (complementary to quantitative measurements) may, therefore, enhance the diagnostic value of scintigraphic techniques. (author).

  4. Increased cell motility and invasion upon knockdown of lipolysis stimulated lipoprotein receptor (LSR in SW780 bladder cancer cells

    Directory of Open Access Journals (Sweden)

    Ørntoft Torben F

    2008-07-01

    Full Text Available Abstract Background Mechanisms underlying the malignant development in bladder cancer are still not well understood. Lipolysis stimulated lipoprotein receptor (LSR has previously been found to be upregulated by P53. Furthermore, we have previously found LSR to be differentially expressed in bladder cancer. Here we investigated the role of LSR in bladder cancer. Methods A time course siRNA knock down experiment was performed to investigate the functional role of LSR in SW780 bladder cancer cells. Since LSR was previously shown to be regulated by P53, siRNA against TP53 was included in the experimental setup. We used Affymetrix GeneChips for measuring gene expression changes and we used Ingenuity Pathway Analysis to investigate the relationship among differentially expressed genes upon siRNA knockdown. Results By Ingenuity Pathway analysis of the microarray data from the different timepoints we identified six gene networks containing genes mainly related to the functional categories "cancer", "cell death", and "cellular movement". We determined that genes annotated to the functional category "cellular movement" including "invasion" and "cell motility" were highly significantly overrepresented. A matrigel assay showed that 24 h after transfection the invasion capacity was significantly increased 3-fold (p Conclusion We conclude that LSR may impair bladder cancer cells from gaining invasive properties.

  5. Progress of research on activation function of NK cell exposed to low dose radiation in adoptive cellular immunotherapy

    International Nuclear Information System (INIS)

    Pan Xiaosong; Shi Yujia; Yao Yimin; Xu Hong; Liu Fenju

    2009-01-01

    Natural killer cells is an important immunological factor in killing malignant cells. Low dose radiation can enhance proliferation and biological activity of NK cell. The involvement of P38MAPK signal pathway and endogenous glutathione induced by LDR may be the probable mechanism. Natural killer cell, especially adherent natural killer cell, is the preferential choice for adoptive cellular immunotherapy, which has a remarkable foreground in malignancy therapy.(authors)

  6. Malignant monoblasts can function as effector cells in natural killer cell and antibody-dependent cellular cytotoxicity assays

    DEFF Research Database (Denmark)

    Hokland, P; Hokland, M; Ellegaard, J

    1981-01-01

    This is the first report describing natural killer (NK) and antibody-dependent cellular cytotoxicity (ADCC) of malignant monoblasts. Pure acute monoblastic leukemia was diagnosed in bone marrow aspirations from two patients by use of conventional cytochemical methods as well as multiple immunolog...... no modulation was seen in ADCC. These findings are discussed in the light of our present knowledge of lymphoid NK cells. Udgivelsesdato: 1981-May...

  7. Asynchrony in the growth and motility responses to environmental changes by individual bacterial cells

    International Nuclear Information System (INIS)

    Umehara, Senkei; Hattori, Akihiro; Inoue, Ippei; Yasuda, Kenji

    2007-01-01

    Knowing how individual cells respond to environmental changes helps one understand phenotypic diversity in a bacterial cell population, so we simultaneously monitored the growth and motility of isolated motile Escherichia coli cells over several generations by using a method called on-chip single-cell cultivation. Starved cells quickly stopped growing but remained motile for several hours before gradually becoming immotile. When nutrients were restored the cells soon resumed their growth and proliferation but remained immotile for up to six generations. A flagella visualization assay suggested that deflagellation underlies the observed loss of motility. This set of results demonstrates that single-cell transgenerational study under well-characterized environmental conditions can provide information that will help us understand distinct functions within individual cells

  8. Functions of NQO1 in Cellular Protection and CoQ10 Metabolism and its Potential Role as a Redox Sensitive Molecular Switch

    Directory of Open Access Journals (Sweden)

    David Ross

    2017-08-01

    Full Text Available NQO1 is one of the two major quinone reductases in mammalian systems. It is highly inducible and plays multiple roles in cellular adaptation to stress. A prevalent polymorphic form of NQO1 results in an absence of NQO1 protein and activity so it is important to elucidate the specific cellular functions of NQO1. Established roles of NQO1 include its ability to prevent certain quinones from one electron redox cycling but its role in quinone detoxification is dependent on the redox stability of the hydroquinone generated by two-electron reduction. Other documented roles of NQO1 include its ability to function as a component of the plasma membrane redox system generating antioxidant forms of ubiquinone and vitamin E and at high levels, as a direct superoxide reductase. Emerging roles of NQO1 include its function as an efficient intracellular generator of NAD+ for enzymes including PARP and sirtuins which has gained particular attention with respect to metabolic syndrome. NQO1 interacts with a growing list of proteins, including intrinsically disordered proteins, protecting them from 20S proteasomal degradation. The interactions of NQO1 also extend to mRNA. Recent identification of NQO1 as a mRNA binding protein have been investigated in more detail using SERPIN1A1 (which encodes the serine protease inhibitor α-1-antitrypsin as a target mRNA and indicate a role of NQO1 in control of translation of α-1-antitrypsin, an important modulator of COPD and obesity related metabolic syndrome. NQO1 undergoes structural changes and alterations in its ability to bind other proteins as a result of the cellular reduced/oxidized pyridine nucleotide ratio. This suggests NQO1 may act as a cellular redox switch potentially altering its interactions with other proteins and mRNA as a result of the prevailing redox environment.

  9. Emergence of coherent motion in aggregates of motile coupled maps

    International Nuclear Information System (INIS)

    Garcia Cantu Ros, A.; Antonopoulos, Ch.G.; Basios, V.

    2011-01-01

    Highlights: → A minimal model of motile particles with adjustable intrinsic steering is presented. → Collective motion emerges due to self-adaptation of each particle's intrinsic state. → Adaptation is achieved by a map which behavior ranges from periodic to chaotic. → Higher cohesion occurs in a balanced combination of ordered and chaotic motion. → Exhibits an abrupt change in degree of coherence as a function of particle density. - Abstract: In this paper we study the emergence of coherence in collective motion described by a system of interacting motiles endowed with an inner, adaptative, steering mechanism. By means of a nonlinear parametric coupling, the system elements are able to swing along the route to chaos. Thereby, each motile can display different types of behavior, i.e. from ordered to fully erratic motion, accordingly with its surrounding conditions. The appearance of patterns of collective motion is shown to be related to the emergence of interparticle synchronization and the degree of coherence of motion is quantified by means of a graph representation. The effects related to the density of particles and to interparticle distances are explored. It is shown that the higher degrees of coherence and group cohesion are attained when the system elements display a combination of ordered and chaotic behaviors, which emerges from a collective self-organization process.

  10. Motility of magnetotactic bacteria/MTB to Geomagnetic fields

    Science.gov (United States)

    Hidajatullah-Maksoed, Fatahillah

    2016-03-01

    Bacteria with motility directed by a local geomagnetic fields have been observed in marine sediments'' discussed by R. Blakemore, 1975. Magnetotactic bacteria/MTB discovered in 1963 by Salvatore Bellini. For ``off-axis electron holography in the transmission electron microscope was used to correlates the physical & magnetic microstructure of magnetite nanocrystals in magnetotactic bacteria'' sought ``single-domain magnetite in hemopelagic sediments'' from JF Stolz. Otherwise, for potential source of bioproducts- product meant from result to multiplier -of magnetotactic bacteria[ACV Araujo, et.al, 2014 ] of marine drugs retrieved the `measurement of cellular chemotaxis with ECIS/Taxis, from KM Pietrosimone, 2012, whereas after ``earth magnetic field role on small living models'' are other interpretation of ``taxis'' as a movement of a cell instead usual ``tax'' for yew's taxus cuspidate, hired car & taxes in financial realms. Acknowledgements to HE. Mr. H. TUK SETYOHADI, Jl. Sriwijaya Raya 3, South-Jakarta, INDONESIA.

  11. Single-cell-based evaluation of sperm progressive motility via fluorescent assessment of mitochondria membrane potential.

    Science.gov (United States)

    Moscatelli, Natalina; Spagnolo, Barbara; Pisanello, Marco; Lemma, Enrico Domenico; De Vittorio, Massimo; Zara, Vincenzo; Pisanello, Ferruccio; Ferramosca, Alessandra

    2017-12-20

    Sperm cells progressive motility is the most important parameter involved in the fertilization process. Sperm middle piece contains mitochondria, which play a critical role in energy production and whose proper operation ensures the reproductive success. Notably, sperm progressive motility is strictly related to mitochondrial membrane potential (MMP) and consequently to mitochondrial functionality. Although previous studies presented an evaluation of mitochondrial function through MMP assessment in entire sperm cells samples, a quantitative approach at single-cell level could provide more insights in the analysis of semen quality. Here we combine laser scanning confocal microscopy and functional fluorescent staining of mitochondrial membrane to assess MMP distribution among isolated spermatozoa. We found that the sperm fluorescence value increases as a function of growing progressive motility and that such fluorescence is influenced by MMP disruptors, potentially allowing for the discrimination of different quality classes of sperm cells in heterogeneous populations.

  12. Cellular imaging using biocompatible dendrimer-functionalized graphene oxide-based fluorescent probe anchored with magnetic nanoparticles

    International Nuclear Information System (INIS)

    Wate, Prateek S; Banerjee, Shashwat S; Mascarenhas, Russel R; Zope, Khushbu R; Khandare, Jayant; Jalota-Badhwar, Archana; Misra, R Devesh K

    2012-01-01

    We describe a novel multicomponent graphene nanostructured system that is biocompatible, and has strong NIR optical absorbance and superparamagnetic properties. The fabrication of the multicomponent nanostructure system involves the covalent attachment of 3 components; Fe 3 O 4 (Fe) nanoparticles, PAMAM-G4-NH 2 (G4) dendrimer and Cy5 (Cy) on a graphene oxide (GO) surface to synthesize a biologically relevant multifunctional system. The resultant GO-G4-Fe-Cy nanosystem exhibits high dispersion in an aqueous medium, and is magnetically responsive and fluorescent. In vitro experiments provide a clear indication of successful uptake of the GO-G4-Fe-Cy nanosystem by MCF-7 breast cancer cells, and it is seen to behave as a bright and stable fluorescent marker. The study also reveals varied cellular distribution kinetics profile for the GO nanostructured system compared to free Cy. Furthermore, the newly developed GO nanostructured system is observed to be non-toxic to MDA-MB-231 cell growth, in striking contrast to free G4 dendrimer and GO-G4 conjugate. The GO-G4-Fe-Cy nanostructured system characterized by multifunctionality suggests the merits of graphene for cellular bioimaging and the delivery of bioactives. (paper)

  13. Cellular and Molecular Mechanisms of the Production of Free Radicals during Exercise and Their Function on Skeletal Muscles

    Directory of Open Access Journals (Sweden)

    2017-06-01

    Full Text Available Physical activity is an integral part of human life. Among significant biological changes during physical activity are increase of metabolism and production of free radicals. Free radical can be defined as molecule or molecular fragments containing unpaired electron in the outer orbital, which react with nearby molecules to obtain stability. These highly reactive molecules have various deleterious effects, such as reduced force generation and increased muscle atrophy. There is evidence that ROS produced during exercise has positive adaptation effects. ROS production leads to increased expression of the anti-oxidants. These molecules, by neutralizing free radicals, neutralize the negative effects of ROS. In addition, exercise-induced ROS leads to the expression of PGC-1α  protein, having a significant impact on various aspects of cell metabolism, mitochondrial biogenesis and cellular respiration as well as metabolism of fat and glucose. This paper provides an overview of the evidence to date on the effects of ROS on exercising muscle. These aspects include the sources of ROS, their positive and negative cellular effects,  role of antioxidants, and ROS-dependent adaptations of muscle cells in response to physical exercise

  14. WHAT IS THE REAL IMPAIRMENT ON ESOPHAGEAL MOTILITY IN PATIENTS WITH GASTROESOPHAGEAL REFLUX DISEASE?

    Directory of Open Access Journals (Sweden)

    Angela FALCÃO

    2013-04-01

    Full Text Available Context Impairment of esophageal motility is a common finding in patients with gastroesophageal reflux disease (GERD as reduced lower esophageal sphincter (LES basal pressure. A very low LES pressure might facilitate the occurrence of more gastroesophageal reflux whereas abnormal esophageal peristalsis may contribute to impaired esophageal clearance after reflux. Objective Evaluate the esophageal motor function of the lower esophageal sphincter and esophageal body in the various forms of gastroesophageal reflux disease. Methods The manometrics records of 268 patients, who had evaluation of the esophageal motility as part of the diagnostic gastroesophageal reflux disease were split into four groups, as follows: 33 patients who had no esophagitis; 92 patients who had erosive esophagitis; 101 patients who had short Barrett's esophagus and 42 patients who had long Barrett's esophagus. Results The group who had long Barrett's esophagus showed smaller mean LES pressure and higher percentage of marked LES hypotonia; in the distal segment of the esophageal body the this group showed higher percentage of marked hypocontractility of the distal segment (<30 mm Hg; this same group showed higher percentage of esophageal motility disorders. Conclusions The most intense esophageal motility disorders and lower pressure of lower esophageal sphincter were noted in the group with long Barrett's esophagus. Those with reflux esophagitis and short Barrett's esophagus had esophageal motility impairment, intermediate among patients with esophagitis and long Barrett's esophagus. Patients with typical symptoms of gastroesophageal reflux but without esophagitis by endoscopy study showed no impairment of esophageal motility.

  15. The relationship between gastrointestinal motility and gastric dilatation-volvulus in dogs.

    Science.gov (United States)

    Gazzola, Krista M; Nelson, Laura L

    2014-09-01

    Gastric dilatation-volvulus (GDV) is a devastating disease that most commonly affects large and giant-breed dogs. Though a number of risk factors have been associated with the development of GDV, the etiology of GDV remains unclear. Abnormal gastric motility patterns and delayed gastric emptying have been previously described in dogs following GDV. Work evaluating the effects of gastropexy procedures and changes to gastric motility after experimental GDV has not found the same changes as those found in dogs with naturally occurring GDV. Although the role of abnormal gastric motility in dogs with GDV will need to be clarified with additional research, such study is likely to be facilitated by improved access to and development of noninvasive measurement techniques for the evaluation of gastric emptying and other motility parameters. In particular, the availability of Food and Drug Administration-approved wireless motility devices for the evaluation of gastrointestinal motility is particularly promising in the study of GDV and other functional gastrointestinal diseases of large and giant-breed dogs. Published by Elsevier Inc.

  16. Twitching motility and biofilm formation are associated with tonB1 in Xylella fastidiosa.

    Science.gov (United States)

    Cursino, Luciana; Li, Yaxin; Zaini, Paulo A; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J

    2009-10-01

    A mutation in the Xylella fastidiosa tonB1 gene resulted in loss of twitching motility and in significantly less biofilm formation as compared with a wild type. The altered motility and biofilm phenotypes were restored by complementation with a functional copy of the gene. The mutation affected virulence as measured by Pierce's disease symptoms on grapevines. The role of TonB1 in twitching and biofilm formation appears to be independent of the characteristic iron-uptake function of this protein. This is the first report demonstrating a functional role for a tonB homolog in X. fastidiosa.

  17. Membrane Lipid Replacement for chronic illnesses, aging and cancer using oral glycerolphospholipid formulations with fructooligosaccharides to restore phospholipid function in cellular membranes, organelles, cells and tissues.

    Science.gov (United States)

    Nicolson, Garth L; Ash, Michael E

    2017-09-01

    Membrane Lipid Replacement is the use of functional, oral supplements containing mixtures of cell membrane glycerolphospholipids, plus fructooligosaccharides (for protection against oxidative, bile acid and enzymatic damage) and antioxidants, in order to safely replace damaged, oxidized, membrane phospholipids and restore membrane, organelle, cellular and organ function. Defects in cellular and intracellular membranes are characteristic of all chronic medical conditions, including cancer, and normal processes, such as aging. Once the replacement glycerolphospholipids have been ingested, dispersed, complexed and transported, while being protected by fructooligosaccharides and several natural mechanisms, they can be inserted into cell membranes, lipoproteins, lipid globules, lipid droplets, liposomes and other carriers. They are conveyed by the lymphatics and blood circulation to cellular sites where they are endocytosed or incorporated into or transported by cell membranes. Inside cells the glycerolphospholipids can be transferred to various intracellular membranes by lipid globules, liposomes, membrane-membrane contact or by lipid carrier transfer. Eventually they arrive at their membrane destinations due to 'bulk flow' principles, and there they can stimulate the natural removal and replacement of damaged membrane lipids while undergoing further enzymatic alterations. Clinical trials have shown the benefits of Membrane Lipid Replacement in restoring mitochondrial function and reducing fatigue in aged subjects and chronically ill patients. Recently Membrane Lipid Replacement has been used to reduce pain and other symptoms as well as removing hydrophobic chemical contaminants, suggesting that there are additional new uses for this safe, natural medicine supplement. This article is part of a Special Issue entitled: Membrane Lipid Therapy: Drugs Targeting Biomembranes edited by Pablo V. Escribá. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights

  18. Sub-cellular localisation studies may spuriously detect the Yes-associated protein, YAP, in nucleoli leading to potentially invalid conclusions of its function.

    Science.gov (United States)

    Finch, Megan L; Passman, Adam M; Strauss, Robyn P; Yeoh, George C; Callus, Bernard A

    2015-01-01

    The Yes-associated protein (YAP) is a potent transcriptional co-activator that functions as a nuclear effector of the Hippo signaling pathway. YAP is oncogenic and its activity is linked to its cellular abundance and nuclear localisation. Activation of the Hippo pathway restricts YAP nuclear entry via its phosphorylation by Lats kinases and consequent cytoplasmic retention bound to 14-3-3 proteins. We examined YAP expression in liver progenitor cells (LPCs) and surprisingly found that transformed LPCs did not show an increase in YAP abundance compared to the non-transformed LPCs from which they were derived. We then sought to ascertain whether nuclear YAP was more abundant in transformed LPCs. We used an antibody that we confirmed was specific for YAP by immunoblotting to determine YAP's sub-cellular localisation by immunofluorescence. This antibody showed diffuse staining for YAP within the cytosol and nuclei, but, noticeably, it showed intense staining of the nucleoli of LPCs. This staining was non-specific, as shRNA treatment of cells abolished YAP expression to undetectable levels by Western blot yet the nucleolar staining remained. Similar spurious YAP nucleolar staining was also seen in mouse embryonic fibroblasts and mouse liver tissue, indicating that this antibody is unsuitable for immunological applications to determine YAP sub-cellular localisation in mouse cells or tissues. Interestingly nucleolar staining was not evident in D645 cells suggesting the antibody may be suitable for use in human cells. Given the large body of published work on YAP in recent years, many of which utilise this antibody, this study raises concerns regarding its use for determining sub-cellular localisation. From a broader perspective, it serves as a timely reminder of the need to perform appropriate controls to ensure the validity of published data.

  19. The zebrafish miR-462/miR-731 cluster is induced under hypoxic stress via hypoxia-inducible factor 1α and functions in cellular adaptations.

    Science.gov (United States)

    Huang, Chun-Xiao; Chen, Nan; Wu, Xin-Jie; Huang, Cui-Hong; He, Yan; Tang, Rong; Wang, Wei-Min; Wang, Huan-Ling

    2015-12-01

    Hypoxia, a unique and essential environmental stress, evokes highly coordinated cellular responses, and hypoxia-inducible factor (HIF) 1 in the hypoxia signaling pathway, an evolutionarily conserved cellular signaling pathway, acts as a master regulator of the transcriptional response to hypoxic stress. MicroRNAs (miRNAs), a major class of posttranscriptional gene expression regulators, also play pivotal roles in orchestrating hypoxia-mediated cellular adaptations. Here, global miRNA expression profiling and quantitative real-time PCR indicated that the up-regulation of the miR-462/miR-731 cluster in zebrafish larvae is induced by hypoxia. It was further validated that miR-462 and miR-731 are up-regulated in a Hif-1α-mediated manner under hypoxia and specifically target ddx5 and ppm1da, respectively. Overexpression of miR-462 and miR-731 represses cell proliferation through blocking cell cycle progress of DNA replication, and induces apoptosis. In situ detection revealed that the miR-462/miR-731 cluster is highly expressed in a consistent and ubiquitous manner throughout the early developmental stages. Additionally, the transcripts become restricted to the notochord, pharyngeal arch, liver, and gut regions from postfertilization d 3 to 5. These data highlight a previously unidentified role of the miR-462/miR-731 cluster as a crucial signaling mediator for hypoxia-mediated cellular adaptations and provide some insights into the potential function of the cluster during embryonic development. © FASEB.

  20. Dual Functional Nanocarrier for Cellular Imaging and Drug Delivery in Cancer Cells Based on π-Conjugated Core and Biodegradable Polymer Arms.

    Science.gov (United States)

    Kulkarni, Bhagyashree; Surnar, Bapurao; Jayakannan, Manickam

    2016-03-14

    Multipurpose polymer nanoscaffolds for cellular imaging and delivery of anticancer drug are urgently required for the cancer therapy. The present investigation reports a new polymer drug delivery concept based on biodegradable polycaprolactone (PCL) and highly luminescent π-conjugated fluorophore as dual functional nanocarrier for cellular imaging and delivery vehicles for anticancer drug to cancer cells. To accomplish this goal, a new substituted caprolactone monomer was designed, and it was subjected to ring opening polymerization using a blue luminescent bishydroxyloligo-phenylenevinylene (OPV) fluorophore as an initiator. A series of A-B-A triblock copolymer building blocks with a fixed OPV π-core and variable chain biodegradable PCL arm length were tailor-made. These triblocks self-assembled in organic solvents to produce well-defined helical nanofibers, whereas in water they produced spherical nanoparticles (size ∼150 nm) with blue luminescence. The hydrophobic pocket of the polymer nanoparticle was found to be an efficient host for loading water insoluble anticancer drug such as doxorubicin (DOX). The photophysical studies revealed that there was no cross-talking between the OPV and DOX chromophores, and their optical purity was retained in the nanoparticle assembly for cellular imaging. In vitro studies revealed that the biodegradable PCL arm was susceptible to enzymatic cleavage at the intracellular lysosomal esterase under physiological conditions to release the loaded drugs. The nascent nanoparticles were found to be nontoxic to cancer cells, whereas the DOX-loaded nanoparticles accomplished more than 80% killing in HeLa cells. Confocal microscopic analysis confirmed the cell penetrating ability of the blue luminescent polymer nanoparticles and their accumulation preferably in the cytoplasm. The DOX loaded red luminescent polymer nanoparticles were also taken up by the cells, and the drug was found to be accumulated at the perinuclear environment

  1. Hyperthermic survival of Chinese hamster ovary cells as a function of cellular population density at the time of plating

    International Nuclear Information System (INIS)

    Highfield, D.P.; Holahan, E.V.; Holahan, P.K.; Dewey, W.C.

    1984-01-01

    The survival of synchronous G 1 or asynchronous Chinese hamster ovary cells in vitro to heat treatment may depend on the cellular population density at the time of heating and/or as the cells are cultured after heating. The addition of lethally irradiated feeder cells may increase survival at 10 -3 by as much as 10- to 100-fold for a variety of conditions when cells are heated either in suspension culture or as monolayers with or without trypsinization. The protective effect associated with feeder cells appears to be associated with close cell-to-cell proximity. However, when cells are heated without trypsinization about 24 hr or later after plating, when adaptation to monolayer has occurred, the protective effect is reduced; i.e., addition of feeder cells enhances survival much less, for example, about 2- to 3-fold at 10 -2 -10 -3 survival. Also, the survival of a cell to heat is independent of whether the neighboring cell in a microcolony is destined to live or die. Finally, if protective effects associated with cell density do occur and are not controlled, serious artifacts can result as the interaction of heat and radiation is studied; for example, survival curves can be moved upward, and thus changed in shape as the number of cells plated is increased with an increase in the hyperthermic treatment or radiation dose following hyperthermia. Therefore, to understand mechanisms and to obtain information relevant to populations of cells in close proximity, such as those in vivo, these cellular population density effects should be considered and understood

  2. Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions.

    Science.gov (United States)

    Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M; Oldfield, Christopher J; Dunker, A Keith; Obradovic, Zoran; Uversky, Vladimir N

    2007-05-01

    Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes approximately 90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions.

  3. Functional Anthology of Intrinsic Disorder. II. Cellular Components, Domains, Technical Terms, Developmental Processes and Coding Sequence Diversities Correlated with Long Disordered Regions

    Science.gov (United States)

    Vucetic, Slobodan; Xie, Hongbo; Iakoucheva, Lilia M.; Oldfield, Christopher J.; Dunker, A. Keith; Obradovic, Zoran; Uversky, Vladimir N.

    2008-01-01

    Biologically active proteins without stable ordered structure (i.e., intrinsically disordered proteins) are attracting increased attention. Functional repertoires of ordered and disordered proteins are very different, and the ability to differentiate whether a given function is associated with intrinsic disorder or with a well-folded protein is crucial for modern protein science. However, there is a large gap between the number of proteins experimentally confirmed to be disordered and their actual number in nature. As a result, studies of functional properties of confirmed disordered proteins, while helpful in revealing the functional diversity of protein disorder, provide only a limited view. To overcome this problem, a bioinformatics approach for comprehensive study of functional roles of protein disorder was proposed in the first paper of this series (Xie H., Vucetic S., Iakoucheva L.M., Oldfield C.J., Dunker A.K., Obradovic Z., Uversky V.N. (2006) Functional anthology of intrinsic disorder. I. Biological processes and functions of proteins with long disordered regions. J. Proteome Res.). Applying this novel approach to Swiss-Prot sequences and functional keywords, we found over 238 and 302 keywords to be strongly positively or negatively correlated, respectively, with long intrinsically disordered regions. This paper describes ~90 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes and coding sequence diversities possessing strong positive and negative correlation with long disordered regions. PMID:17391015

  4. CD155/PVR plays a key role in cell motility during tumor cell invasion and migration

    International Nuclear Information System (INIS)

    Sloan, Kevin E; Ilag, Leodevico L; Jay, Daniel G; Eustace, Brenda K; Stewart, Jean K; Zehetmeier, Carol; Torella, Claudia; Simeone, Marina; Roy, Jennifer E; Unger, Christine; Louis, David N

    2004-01-01

    Invasion is an important early step of cancer metastasis that is not well understood. Developing therapeutics to limit metastasis requires the identification and validation of candidate proteins necessary for invasion and migration. We developed a functional proteomic screen to identify mediators of tumor cell invasion. This screen couples Fluorophore Assisted Light Inactivation (FALI) to a scFv antibody library to systematically inactivate surface proteins expressed by human fibrosarcoma cells followed by a high-throughput assessment of transwell invasion. Using this screen, we have identified CD155 (the poliovirus receptor) as a mediator of tumor cell invasion through its role in migration. Knockdown of CD155 by FALI or by RNAi resulted in a significant decrease in transwell migration of HT1080 fibrosarcoma cells towards a serum chemoattractant. CD155 was found to be highly expressed in multiple cancer cell lines and primary tumors including glioblastoma (GBM). Knockdown of CD155 also decreased migration of U87MG GBM cells. CD155 is recruited to the leading edge of migrating cells where it colocalizes with actin and αv-integrin, known mediators of motility and adhesion. Knockdown of CD155 also altered cellular morphology, resulting in cells that were larger and more elongated than controls when plated on a Matrigel substrate. These results implicate a role for CD155 in mediating tumor cell invasion and migration and suggest that CD155 may contribute to tumorigenesis

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

    Directory of Open Access Journals (Sweden)

    Jan W P Kuiper

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

  6. Effects of acamprosate on attentional set-shifting and cellular function in the prefrontal cortex of chronic alcohol-exposed mice

    Science.gov (United States)

    Hu, Wei

    Background: The medial prefrontal cortex (mPFC) inhibits impulsive and compulsive behaviors that characterize drug abuse and dependence. Acamprosate is the leading medication approved for the maintenance of abstinence, shown to reduce craving and relapse in animal models and human alcoholics. Whether acamprosate can modulate executive functions that are impaired by chronic ethanol exposure is unknown. Here we explored the effects of acamprosate on an attentional set-shifting task, and tested whether these behavioral effects are correlated with modulation of glutamatergic synaptic transmission and intrinsic excitability of mPFC neurons. Methods: We induced alcohol dependence in mice via chronic intermittent ethanol (CIE) exposure in vapor chambers and measured changes in alcohol consumption in a limited access 2-bottle choice paradigm. Impairments of executive function were assessed in an attentional set-shifting task. Acamprosate was applied subchronically for 2 days during withdrawal before the final behavioral test. Alcohol-induced changes in cellular function of layer 5/6 pyramidal neurons, and the potential modulation of these changes by acamprosate, were measured using patch clamp recordings in brain slices. Results: Chronic ethanol exposure impaired cognitive flexibility in the attentional set-shifting task. Acamprosate improved overall performance and reduced perseveration. Recordings of mPFC neurons showed that chronic ethanol exposure increased use-dependent presynaptic transmitter release and enhanced postsynaptic N-methyl-D-aspartate receptor (NMDAR) function. Moreover, CIE-treatment lowered input resistance, and decreased the threshold and the afterhyperpolarization (AHP) of action potentials, suggesting chronic ethanol exposure also impacted membrane excitability of mPFC neurons. However, acamprosate treatment did not reverse these ethanol-induced changes cellular function. Conclusion: Acamprosate improved attentional control of ethanol exposed animals

  7. Multi-functionality Redefined with Colloidal Carotene Carbon Nanoparticles for Synchronized Chemical Imaging, Enriched Cellular Uptake and Therapy

    OpenAIRE

    Misra, Santosh K.; Mukherjee, Prabuddha; Chang, Huei-Huei; Tiwari, Saumya; Gryka, Mark; Bhargava, Rohit; Pan, Dipanjan

    2016-01-01

    Typically, multiplexing high nanoparticle uptake, imaging, and therapy requires careful integration of three different functions of a multiscale molecular-particle assembly. Here, we present a simpler approach to multiplexing by utilizing one component of the system for multiple functions. Specifically, we successfully synthesized and characterized colloidal carotene carbon nanoparticle (C3-NP), in which a single functional molecule served a threefold purpose. First, the presence of carotene ...

  8. Increased count, motility, and total motile sperm cells collected across three consecutive ejaculations within 24 h of oocyte retrieval: implications for management of men presenting with low numbers of motile sperm for assisted reproduction.

    Science.gov (United States)

    Said, Al-Hasen; Reed, Michael L

    2015-07-01

    The purpose of this study was to quantitate changes in seminal volume, sperm count, motility, qualitative forward progression, and total motile sperm cells per ejaculate, across three consecutive ejaculates collected from individuals within 24 h preceding an IVF cycle. Men presenting with oligoasthenozoospermia or asthenozoospemia attempted three ejaculates within 24 h preceding IVF. Ejaculate 1 was produced the afternoon prior to oocyte retrieval, and ejaculates 2 and 3 were produced the morning of oocyte retrieval with 2-3 h between collections. Ejaculates 1 and 2 were extended 1:1 v/v with room temperature rTYBS. Test tubes were placed into a beaker of room temperature water, then placed at 4 °C for gradual cooling. Ejaculate 3 was not extended, but pooled with ejaculates 1 and 2 and processed for intracytoplasmic sperm injection (ICSI). Out of 109 oocyte retrievals, 28 men were asked to attempt multiple consecutive ejaculations. Among this population, 25/28 (89.3 %) were successful, and 3/28 men (10.7 %) could only produce two ejaculates. Mean volumes for ejaculates 1, 2, and 3 were significantly different from each other (p sperm counts, motility, qualitative forward progression, and total motile cells per ejaculate for the ejaculates1, 2, and 3 demonstrated the following: ejaculates 2 and 3 were not significantly different, but counts, motility, and total motile sperm were improved over ejaculate 1 (p sperm in this population by 8-fold compared to the first ejaculate alone, facilitating avoidance of sperm cryopreservation and additional centrifugation steps that could affect sperm viability and/or function.

  9. Cellular MR Imaging

    Directory of Open Access Journals (Sweden)

    Michel Modo

    2005-07-01

    Full Text Available Cellular MR imaging is a young field that aims to visualize targeted cells in living organisms. In order to provide a different signal intensity of the targeted cell, they are either labeled with MR contrast agents in vivo or prelabeled in vitro. Either (ultrasmall superparamagnetic iron oxide [(USPIO] particles or (polymeric paramagnetic chelates can be used for this purpose. For in vivo cellular labeling, Gd3+- and Mn2+- chelates have mainly been used for targeted hepatobiliary imaging, and (USPIO-based cellular imaging has been focused on imaging of macrophage activity. Several of these magneto-pharmaceuticals have been FDA-approved or are in late-phase clinical trials. As for prelabeling of cells in vitro, a challenge has been to induce a sufficient uptake of contrast agents into nonphagocytic cells, without affecting normal cellular function. It appears that this issue has now largely been resolved, leading to an active research on monitoring the cellular biodistribution in vivo following transplantation or transfusion of these cells, including cell migration and trafficking. New applications of cellular MR imaging will be directed, for instance, towards our understanding of hematopoietic (immune cell trafficking and of novel guided (stem cell-based therapies aimed to be translated to the clinic in the future.

  10. Transverse loop colostomy and colonic motility.

    Science.gov (United States)

    Pucciani, F; Ringressi, M N; Maltinti, G; Bechi, P

    2014-11-01

    The motility of the defunctionalized colon, distal to transverse loop colostomy, has never been studied "in vivo." The aim of our study was to evaluate the influence of transverse loop colostomy on colonic motility. Thirteen patients were examined before stoma closure by means of clinical evaluation and colonic manometry; we studied both the right and distal colon in both fasting and fed patients in order to detect motor activity. Quantitative and qualitative manometric analyses showed that the diverted colon had motor activity even if no regular colonic motor pattern was observed. The spreading of aboral propagated contractions (PCs) was sometimes recorded from the right colon to the distal colon. The response of the proximal and distal colon to a standard meal, when compared to fasting values, increased more than 40 and 35 %, respectively. Stool and gas ejections from the colostomy were never related to a particular type of colonic motility: Motor quiescence such as PCs was chaotically related to stool escape. In conclusion, motility of the defunctionalized colon is preserved in patients with transverse loop colostomy.

  11. Flagellar Motility of Trypanosoma cruzi Epimastigotes

    Directory of Open Access Journals (Sweden)

    G. Ballesteros-Rodea

    2012-01-01

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

  12. Chicago Classification of Esophageal Motility Disorders: Lessons Learned

    NARCIS (Netherlands)

    Rohof, W. O. A.; Bredenoord, A. J.

    2017-01-01

    High-resolution manometry (HRM) is increasingly performed worldwide, to study esophageal motility. The Chicago classification is subsequently applied to interpret the manometric findings and facilitate a diagnosis of esophageal motility disorders. This review will discuss new insights regarding the

  13. Regional gastrointestinal contractility parameters using the wireless motility capsule

    DEFF Research Database (Denmark)

    Farmer, A D; Wegeberg, A-M L; Brock, B

    2018-01-01

    BACKGROUND: The wireless motility capsule concurrently measures temperature, pH and pressure as it traverses the gastrointestinal tract. AIMS: To describe normative values for motility/contractility parameters across age, gender and testing centres. METHODS: Healthy participants underwent...

  14. Metabolomics Reveals New Mechanisms for Pathogenesis in Barth Syndrome and Introduces Novel Roles for Cardiolipin in Cellular Function.

    Directory of Open Access Journals (Sweden)

    Yana Sandlers

    Full Text Available Barth Syndrome is the only known Mendelian disorder of cardiolipin remodeling, with characteristic clinical features of cardiomyopathy, skeletal myopathy, and neutropenia. While the primary biochemical defects of reduced mature cardiolipin and increased monolysocardiolipin are well-described, much of the downstream biochemical dysregulation has not been uncovered, and biomarkers are limited. In order to further expand upon the knowledge of the biochemical abnormalities in Barth Syndrome, we analyzed metabolite profiles in plasma from a cohort of individuals with Barth Syndrome compared to age-matched controls via 1H nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry. A clear distinction between metabolite profiles of individuals with Barth Syndrome and controls was observed, and was defined by an array of metabolite classes including amino acids and lipids. Pathway analysis of these discriminating metabolites revealed involvement of mitochondrial and extra-mitochondrial biochemical pathways including: insulin regulation of fatty acid metabolism, lipid metabolism, biogenic amine metabolism, amino acid metabolism, endothelial nitric oxide synthase signaling, and tRNA biosynthesis. Taken together, this data indicates broad metabolic dysregulation in Barth Syndrome with wide cellular effects.

  15. On the Action of General Anesthetics on Cellular Function: Barbiturate Alters the Exocytosis of Catecholamines in a Model Cell System.

    Science.gov (United States)

    Ye, Daixin; Ewing, Andrew

    2018-01-22

    General anesthetics are essential in many areas, however, the cellular mechanisms of anesthetic-induced amnesia and unconsciousness are incompletely understood. Exocytosis is the main mechanism of signal transduction and neuronal communication through the release of chemical transmitters from vesicles to the extracellular environment. Here, we use disk electrodes placed on top of PC12 cells to show that treatment with barbiturate induces fewer molecules released during exocytosis and changes the event dynamics perhaps by inducing a less stable fusion pore that is prone to close faster during partial exocytosis. Larger events are essentially abolished. However, use of intracellular vesicle impact electrochemical cytometry using a nano-tip electrode inserted into a cell shows that the distribution of vesicle transmitter content does not change after barbiturate treatment. This indicates that barbiturate selectively alters the pore size of larger events or perhaps differentially between types of vesicles. Alteration of exocytosis in this manner could be linked to the effects of general anesthetics on memory loss. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Resveratrol and Red Wine Function as Antioxidants in the Nervous System without Cellular Proliferative Effects during Experimental Diabetes

    Science.gov (United States)

    Venturini, Carina Duarte; Merlo, Suélen; Souto, André Arigony; Fernandes, Marilda da Cruz; Gomez, Rosane; Rhoden, Claudia Ramos

    2010-01-01

    Chronic hyperglycemia increases oxidative stress status and has been associated with neurological complications in diabetic individuals. This study compared the antioxidant properties of red wine or resveratrol in different brain areas of diabetic and non-diabetic rats, and investigated the effect of them on hippocampal cell proliferation in hippocampal dentate gyrus of diabetic rats. Streptozotocin-induced diabetic and control rats were treated with red wine (4 mL/kg), resveratrol (20 mg/kg) or saline, by oral gavage, for 21 days. Lipid peroxidation (TBARS), catalase and superoxide dismutase were measured to evaluate the oxidative stress and the BrdU-positive cells were assessed to measure changes in cellular proliferation. In diabetic animals, resveratrol showed antioxidant property in the hippocampus and in the striatum, while red wine had an antioxidant effect only in the hippocampus. Neither red wine nor resveratrol reversed the lower hippocampal cell proliferation in diabetic rats. Daily doses of red wine or resveratrol have an antioxidant effect in rats depending on the brain area and the glycemic status. PMID:21307644

  17. Resveratrol and Red Wine Function as Antioxidants in the Nervous System without Cellular Proliferative Effects during Experimental Diabetes

    Directory of Open Access Journals (Sweden)

    Carina Duarte Venturini

    2010-01-01

    Full Text Available Chronic hyperglycemia increases oxidative stress status and has been associated with neurological complications in diabetic individuals. This study compared the antioxidant properties of red wine or resveratrol in different brain areas of diabetic and non-diabetic rats, and investigated the effect of them on hippocampal cell proliferation in hippocampal dentate gyrus of diabetic rats. Streptozotocin-induced diabetic and control rats were treated with red wine (4 mL/kg, resveratrol (20 mg/kg or saline, by oral gavage, for 21 days. Lipid peroxidation (TBARS, catalase and superoxide dismutase were measured to evaluate the oxidative stress and the BrdU-positive cells were assessed to measure changes in cellular proliferation. In diabetic animals, resveratrol showed antioxidant property in the hippocampus and in the striatum, while red wine had an antioxidant effect only in the hippocampus. Neither red wine nor resveratrol reversed the lower hippocampal cell proliferation in diabetic rats. Daily doses of red wine or resveratrol have an antioxidant effect in rats depending on the brain area and the glycemic status.

  18. Allele-specific Gene Silencing of Mutant mRNA Restores Cellular Function in Ullrich Congenital Muscular Dystrophy Fibroblasts

    Directory of Open Access Journals (Sweden)

    Satoru Noguchi

    2014-01-01

    Full Text Available Ullrich congenital muscular dystrophy (UCMD is an inherited muscle disorder characterized clinically by muscle weakness, distal joint hyperlaxity, and proximal joint contractures. Sporadic and recessive mutations in the three collagen VI genes, COL6A1, COL6A2, and COL6A3, are reported to be causative. In the sporadic forms, a heterozygous point mutation causing glycine substitution in the triple helical domain has been identified in higher rate. In this study, we examined the efficacy of siRNAs, which target point mutation site, on specific knockdown toward transcripts from mutant allele and evaluated consequent cellular phenotype of UCMD fibroblasts. We evaluated the effect of siRNAs targeted to silence-specific COL6A1 alleles in UCMD fibroblasts, where simultaneous expression of both wild-type and mutant collagen VI resulted in defective collagen localization. Addition of mutant-specific siRNAs allowed normal extracellular localization of collagen VI surrounding fibroblasts, suggesting selective inhibition of mutant collagen VI. Targeting the single-nucleotide COL6A1 c.850G>A (p.G284R mutation responsible a sporadic autosomal dominant form of UCMD can potently and selectively block expression of mutant collagen VI. These results suggest that allele-specific knockdown of the mutant mRNA can potentially be considered as a therapeutic procedure in UCMD due to COL6A1 point mutations.

  19. Cellular radiation response as a function of tumor size, host hematocrit, and erythrokinetics in CA755 tumor-bearing mice

    International Nuclear Information System (INIS)

    Jirtle, R.L.

    1977-01-01

    Experiments were performed which both characterized the kinetics of host anemia when CA755 mammary adenocarcinomas were grown in either preirradiated or unirradiated host tissue of C57B1/2J (BDF 1 ) mice, and determined whether a correlation exists between the extent of host anemia and the cellular radiosensitivity of the grossly viable tumor tissue. The red cell destruction rate and the total red cell volume (TRCV) were simultaneously measured throughout tumor growth, and from this information the erythrocyte production per day could be estimated. Increased erythrocyte production was accompanied by a corresponding increase in circulating reticulocytes. The application of these methods to a tumor-bearing mouse system demonstrated that the erythrocyte production rates increased to a maximum of 6 to 10 times normal in mice bearing tumors growing in either preirradiated or unirradiated graft sites. It was concluded that tumor host anemia was due to accelerated random loss of erythrocytes and the nearly simultaneous decrease in erythrocyte potential life span rather than to a decrease in the erythrocyte production

  20. The functional state of cellular antioxidant defence system of shoots of Arabidopsis thaliana exposed to the chronic ionizing radiation in the Chornobyl exclusion zone

    International Nuclear Information System (INIS)

    Morozova, V.S.; Kashparov, V.A.; Levchuk, S.Ye.; Umanska, A.O.; Bishchuk, Ye.V.; Otreshko, L.M

    2016-01-01

    The functional state of the cellular antioxidant defence system of shoots of Arabidopsis thaliana plants that grow in natural conditions in the areas of the Chornobyl Exclusion Zone with the values of the external dose rate of 0.45, 0.61, 1.05, 4.81 and 6.80 .Gy/h was evaluated. The decrease of the content of thiobarbituric acid reactive compounds in the shoots of Arabidopsis thaliana was revealed under the external dose rate of 4.81 and 6.80 .Gy/h by 38 and 48 %, respectively, compared to this parameter value under the external dose rate of 0.45 .Gy/h. In the investigated samples the capacity of guaiacol peroxidase increases, catalase and ascorbate peroxidase decreases significantly with the increase of the external dose rate from 0.45 to 6.80 .Gy/h. Probably, revealed changes in the functional state of the cellular antioxidant defence system of the shoots of Arabidopsis thaliana in the conditions of radioactive contamination are adaptive in nature.

  1. Twitching motility and biofilm formation are associated with tonB1 in Xylella fastidiosa

    OpenAIRE

    Cursino, Luciana; Li, Yaxin; Zaini, Paulo A.; De La Fuente, Leonardo; Hoch, Harvey C.; Burr, Thomas J.

    2017-01-01

    A mutation in the Xylella fastidiosa tonB1 gene resulted in loss of twitching motility and in significantly less biofilm formation as compared with a wild type. The altered motility and biofilm phenotypes were restored by complementation with a functional copy of the gene. The mutation affected virulence as measured by Pierce's disease symptoms on grapevines. The role of TonB1 in twitching and biofilm formation appears to be independent of the characteristic iron-uptake function of this prote...

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

    Directory of Open Access Journals (Sweden)

    Pintu Patra

    2016-06-01

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

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

    Science.gov (United States)

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

    2016-06-01

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

  4. Investigation of a calcium-responsive contrast agent in cellular model systems: feasibility for use as a smart molecular probe in functional MRI.

    Science.gov (United States)

    Angelovski, Goran; Gottschalk, Sven; Milošević, Milena; Engelmann, Jörn; Hagberg, Gisela E; Kadjane, Pascal; Andjus, Pavle; Logothetis, Nikos K

    2014-05-21

    Responsive or smart contrast agents (SCAs) represent a promising direction for development of novel functional MRI (fMRI) methods for the eventual noninvasive assessment of brain function. In particular, SCAs that respond to Ca(2+) may allow tracking neuronal activity independent of brain vasculature, thus avoiding the characteristic limitations of current fMRI techniques. Here we report an in vitro proof-of-principle study with a Ca(2+)-sensitive, Gd(3+)-based SCA in an attempt to validate its potential use as a functional in vivo marker. First, we quantified its relaxometric response in a complex 3D cell culture model. Subsequently, we examined potential changes in the functionality of primary glial cells following administration of this SCA. Monitoring intracellular Ca(2+) showed that, despite a reduction in the Ca(2+) level, transport of Ca(2+) through the plasma membrane remained unaffected, while stimulation with ATP induced Ca(2+)-transients suggested normal cellular signaling in the presence of low millimolar SCA concentrations. SCAs merely lowered the intracellular Ca(2+) level. Finally, we estimated the longitudinal relaxation times (T1) for an idealized in vivo fMRI experiment with SCA, for extracellular Ca(2+) concentration level changes expected during intense neuronal activity which takes place upon repetitive stimulation. The values we obtained indicate changes in T1 of around 1-6%, sufficient to be robustly detectable using modern MRI methods in high field scanners. Our results encourage further attempts to develop even more potent SCAs and appropriate fMRI protocols. This would result in novel methods that allow monitoring of essential physiological processes at the cellular and molecular level.

  5. Clinical Application of Esophageal High-resolution Manometry in the Diagnosis of Esophageal Motility Disorders.

    Science.gov (United States)

    van Hoeij, Froukje B; Bredenoord, Albert J

    2016-01-31

    Esophageal high-resolution manometry (HRM) is replacing conventional manometry in the clinical evaluation of patients with esophageal symptoms, especially dysphagia. The introduction of HRM gave rise to new objective metrics and recognizable patterns of esophageal motor function, requiring a new classification scheme: the Chicago classification. HRM measurements are more detailed and more easily performed compared to conventional manometry. The visual presentation of acquired data improved the analysis and interpretation of esophageal motor function. This led to a more sensitive, accurate, and objective analysis of esophageal motility. In this review we discuss how HRM changed the way we define and categorize esophageal motility disorders. Moreover, we discuss the clinical applications of HRM for each esophageal motility disorder separately.

  6. Investigation of microgravity effects on basic imune functions on the cellular level - The TRIPLELUX-B experiment

    Science.gov (United States)

    Unruh, Eckehardt; Hansen, Peter-Diedrich

    Hemocytes are the primary defence of the Blue Mussel against invading microorganisms and foreign particles. The hemocytes of mussels as part of the immune system of invertebrates has not been studied so far in space. The choice of the phagocytes from invertebrates is justified by the claim to study the universal validity of innate immune responses. The hemocytes of mussels have a lot in common with macrophages of higher organisms. They are able to detect the presence of microorganisms and kill these microorganisms by phagocytosis. The phagocy-tosis related production of ROS will be stimulated with opsonised zymosan. The hemocytes will be stored frozen and reconstituted in-flight for the experiment. The signals of the im-muno cellular responses are translated into luminescence as a rapid optical reporter system. The primary aim of Triplelux B is to investigate under space flight conditions the effect of microgravity on the ability of isolated Blue Mussel hemocytes to perform phagocytosis. As a secondery objectiv, the results expected will allow to conclude whether the observed responses are caused by microgravity and/or radiation (change in permeability, endpoints in genotoxicity: DNA unwinding). The TRIPLELUX-B Experiment contributes to risk assessment concerning immunotoxicity under space flight conditions. The components of the fully automated AEC (Advanced Experimental Containment) will be demonstrated. The AEC of the TRIPLELUX-B experiment will contribute to a real time operational monitoring for immunotoxicity testing for earth. Blue mussels have been used repeatedly for monitoring imunotoxicity and genotoxicity in coastal waters. Based on the AEC an automatet measuring device will allow "real time monitoring" providing observations of immunotoxicity in coastal and inland waters.

  7. Toxicity of functional nano-micro zinc oxide tetrapods: impact of cell culture conditions, cellular age and material properties.

    Science.gov (United States)

    Papavlassopoulos, Heike; Mishra, Yogendra K; Kaps, Sören; Paulowicz, Ingo; Abdelaziz, Ramzy; Elbahri, Mady; Maser, Edmund; Adelung, Rainer; Röhl, Claudia

    2014-01-01

    With increasing production and applications of nanostructured zinc oxide, e.g., for biomedical and consumer products, the question of safety is getting more and more important. Different morphologies of zinc oxide structures have been synthesized and accordingly investigated. In this study, we have particularly focused on nano-micro ZnO tetrapods (ZnO-T), because their large scale fabrication has been made possible by a newly introduced flame transport synthesis approach which will probably lead to several new applications. Moreover, ZnO-T provide a completely different morphology then classical spherical ZnO nanoparticles. To get a better understanding of parameters that affect the interactions between ZnO-T and mammalian cells, and thus their biocompatibility, we have examined the impact of cell culture conditions as well as of material properties on cytotoxicity. Our results demonstrate that the cell density of fibroblasts in culture along with their age, i.e., the number of preceding cell divisions, strongly affect the cytotoxic potency of ZnO-T. Concerning the material properties, the toxic potency of ZnO-T is found to be significantly lower than that of spherical ZnO nanoparticles. Furthermore, the morphology of the ZnO-T influenced cellular toxicity in contrast to surface charges modified by UV illumination or O2 treatment and to the material age. Finally, we have observed that direct contact between tetrapods and cells increases their toxicity compared to transwell culture models which allow only an indirect effect via released zinc ions. The results reveal several parameters that can be of importance for the assessment of ZnO-T toxicity in cell cultures and for particle development.

  8. Undersized description on motile gyrotactic micro-organisms individualities in MHD stratified water-based Newtonian nanofluid

    Science.gov (United States)

    Rehman, Khalil Ur; Malik, Aneeqa Ashfaq; Tahir, M.; Malik, M. Y.

    2018-03-01

    The current pagination summarized the influence of bio-convection Schmidt number, bio-convection Peclet number and micro-organisms concentration difference parameter on the density of motile gyrotactic micro-organisms when they have interaction with the thermally stratified magneto-nanofluid flow past a vertical stretching surface. It is observed that the density of motile microorganisms is the decreasing function of the bio-convection Schmidt and Peclet numbers. It is trusted that the outcomes of present analysis will serve as a helping source for the upcoming developments regarding individualities of motile gyrotactic micro-organisms subject to boundary layer flows induced by stretching surfaces.

  9. Transformation of ultraviolet-irradiated human fibroblasts by simian virus 40 is enhanced by cellular DNA repair functions

    International Nuclear Information System (INIS)

    Hall, J.D.

    1981-01-01

    Human fibroblasts irradiated with ultraviolet light were either tested for survival (colony formation) or infected with simian virus 40 and examined for transformation (foci formation). For normal cell cultures, the fractions of surviving colonies which were also transformed increased with increasing irradiation dose. In contrast, little increase in the transformation of ultraviolet-irradiated repair-deficient (xeroderma pigmentosum and xeroderma pigmentosum variant) cells was observed. Similar experiments with xeroderma pigmentosum variant cells treated with caffeine following irradiation indicated that, under these conditions, the deficient cells produced more transformants among the survivors of ultraviolet irradiation than did unirradiated cells. These results suggest (1) that DNA repair functions, not DNA damage per se, are required for enhanced viral transformation in normal cells; (2) that functions involved in excision repair and functions needed for replication of ultraviolet-damaged DNA appear necessary for this stimulation; and (3) that blocking DNA replication in ultraviolet-irradiated xeroderma pigmentosum variant cells by caffeine enhances viral transformation. (Auth.)

  10. Regulation of Mitochondrial Function and Cellular Energy Metabolism by Protein Kinase C-λ/ι: A Novel Mode of Balancing Pluripotency

    Science.gov (United States)

    Mahato, Biraj; Home, Pratik; Rajendran, Ganeshkumar; Paul, Arindam; Saha, Biswarup; Ganguly, Avishek; Ray, Soma; Roy, Nairita; Swerdlow, Russell H.; Paul, Soumen

    2014-01-01

    Pluripotent stem cells (PSCs) contain functionally immature mitochondria and rely upon high rates of glycolysis for their energy requirements. Thus, altered mitochondrial function and promotion of aerobic glycolysis is key to maintain and induce pluripotency. However, signaling mechanisms that regulate mitochondrial function and reprogram metabolic preferences in self-renewing vs. differentiated PSC populations are poorly understood. Here, using murine embryonic stem cells (ESCs) as a model system, we demonstrate that atypical protein kinase C isoform, PKC lambda/iota (PKCλ/ι), is a key regulator of mitochondrial function in ESCs. Depletion of PKCλ/ι in ESCs maintains their pluripotent state as evident from germline offsprings. Interestingly, loss of PKCλ/ι in ESCs leads to impairment in mitochondrial maturation, organization and a metabolic shift toward glycolysis under differentiating condition. Our mechanistic analyses indicate that a PKCλ/ι-HIF1α-PGC1α axis regulates mitochondrial respiration and balances pluripotency in ESCs. We propose that PKCλ/ι could be a crucial regulator of mitochondrial function and energy metabolism in stem cells and other cellular contexts. PMID:25142417

  11. The Kunitz-protease inhibitor domain in amyloid precursor protein reduces cellular mitochondrial enzymes expression and function.

    Science.gov (United States)

    Chua, Li-Min; Lim, Mei-Li; Wong, Boon-Seng

    2013-08-09

    Mitochondrial dysfunction is a prominent feature of Alzheimer's disease (AD) and this can be contributed by aberrant metabolic enzyme function. But, the mechanism causing this enzymatic impairment is unclear. Amyloid precursor protein (APP) is known to be alternatively spliced to produce three major isoforms in the brain (APP695, APP751, APP770). Both APP770 and APP751 contain the Kunitz Protease Inhibitory (KPI) domain, but the former also contain an extra OX-2 domain. APP695 on the other hand, lacks both domains. In AD, up-regulation of the KPI-containing APP isoforms has been reported. But the functional contribution of this elevation is unclear. In the present study, we have expressed and compared the effect of the non-KPI containing APP695 and the KPI-containing APP751 on mitochondrial function. We found that the KPI-containing APP751 significantly decreased the expression of three major mitochondrial metabolic enzymes; citrate synthase, succinate dehydrogenase and cytochrome c oxidase (COX IV). This reduction lowers the NAD(+)/NADH ratio, COX IV activity and mitochondrial membrane potential. Overall, this study demonstrated that up-regulation of the KPI-containing APP isoforms is likely to contribute to the impairment of metabolic enzymes and mitochondrial function in AD. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. The physics of the unconventional motility strategy of euglenids

    Science.gov (United States)

    Arroyo, Marino; Noselli, Giovanni; Desimone, Antonio

    Euglenids are a family of unicellular protists, which use flagella to move in a fluid. However, they are also capable of performing elegantly concerted large amplitude deformations of the cell shape, in what is known as metaboly. To perform metaboly, euglenids use an elaborate cortical complex capable of actively imposing spatially modulated shear deformations on the cell surface. This mode of cell deformation has been linked to motility, but biophysical studies have demonstrated that it leads to very small swimming velocities as compared to flagellar locomotion. Furthermore, why would these cells possess two elaborate apparatus for the same function remains unclear. In this work, we combine experimental observations of euglena gracilis cells with theoretical models to shed light into the function of metaboly. The theoretical models account for the force generation and shape evolution at the cell envelop, together with the mechanical interaction of the cell with its environment. We characterize the efficiency of the two modes of locomotion of this cells in terms of the physical nature of their environment. ERC AdG 340685 MicroMotility.

  13. From understanding cellular function to novel drug discovery: the role of planar patch-clamp array chip technology

    Directory of Open Access Journals (Sweden)

    Christophe ePy

    2011-10-01

    Full Text Available All excitable cell functions rely upon ion channels that are embedded in their plasma membrane. Perturbations of ion channel structure or function result in pathologies ranging from cardiac dysfunction to neurodegenerative disorders. Consequently, to understand the functions of excitable cells and to remedy their pathophysiology, it is important to understand the ion channel functions under various experimental conditions – including exposure to novel drug targets. Glass pipette patch-clamp is the state of the art technique to monitor the intrinsic and synaptic properties of neurons. However, this technique is labor-intensive and has low data throughput. Planar patch-clamp chips, integrated into automated systems, offer high throughputs but are limited to isolated cells from suspensions, resulting in questionable models of true physiological function, and are unsuitable for studies involving neuronal communication. Multi-electrode arrays (MEA, in contrast, have the ability to monitor network activity by measuring local field potentials from multiple extracellular sites, but specific ion channel activity is challenging to extract from these multiplexed signals. Here we describe a novel planar patch-clamp chip technology that enables the simultaneous high resolution electrophysiological interrogation of individual neurons at multiple sites in synaptically connected neuronal networks, thereby combining the advantages of MEA and patch-clamp techniques. Each neuron can be probed through an aperture that connects to a dedicated subterranean microfluidic channel. Neurons growing in networks are aligned to the apertures by physisorbed or chemisorbed chemical cues. In this review, we describe the design and fabrication process of these chips, the approach to the chemical patterning for cell placement, and present physiological data from cultured neuronal cells.

  14. Relationship of Total Motile Sperm Count and Percentage Motile Sperm to Successful Pregnancy Rates Following Intrauterine Insemination

    OpenAIRE

    Pasqualotto, Eleonora B.; Daitch, James A.; Hendin, Benjamin N.; Falcone, Tommaso; Thomas, Anthony J.; Nelson, David R.; Agarwal, Ashok

    1999-01-01

    Purpose:This study sought (i) to investigate the relationship between postwash total motile sperm count and postwash percentage motile sperm in predicting successful intrauterine insemination and (ii) to determine the minimal postwash total motile sperm count required to achieve pregnancy with intrauterine insemination.

  15. Multiple Functional Domains and Complexes of the Two Nonstructural Proteins of Human Respiratory Syncytial Virus Contribute to Interferon Suppression and Cellular Location▿

    Science.gov (United States)

    Swedan, Samer; Andrews, Joel; Majumdar, Tanmay; Musiyenko, Alla; Barik, Sailen

    2011-01-01

    Human respiratory syncytial virus (RSV), a major cause of severe respiratory diseases, efficiently suppresses cellular innate immunity, represented by type I interferon (IFN), using its two unique nonstructural proteins, NS1 and NS2. In a search for their mechanism, NS1 was previously shown to decrease levels of TRAF3 and IKKε, whereas NS2 interacted with RIG-I and decreased TRAF3 and STAT2. Here, we report on the interaction, cellular localization, and functional domains of these two proteins. We show that recombinant NS1 and NS2, expressed in lung epithelial A549 cells, can form homo- as well as heteromers. Interestingly, when expressed alone, substantial amounts of NS1 and NS2 localized to the nuclei and to the mitochondria, respectively. However, when coexpressed with NS2, as in RSV infection, NS1 could be detected in the mitochondria as well, suggesting that the NS1-NS2 heteromer localizes to the mitochondria. The C-terminal tetrapeptide sequence, DLNP, common to both NS1 and NS2, was required for some functions, but not all, whereas only the NS1 N-terminal region was important for IKKε reduction. Finally, NS1 and NS2 both interacted specifically with host microtubule-associated protein 1B (MAP1B). The contribution of MAP1B in NS1 function was not tested, but in NS2 it was essential for STAT2 destruction, suggesting a role of the novel DLNP motif in protein-protein interaction and IFN suppression. PMID:21795342

  16. Results from functional and cellular studies using an ovine model to assess response to mesenchymal stem cell therapy after induction of myocardial infarction

    International Nuclear Information System (INIS)

    Bailey, Elizabeth A.; Bailey, Dale L; Roach, Paul J.; Bautovich, George; Hunyor, Stephen

    2009-01-01

    Full text: Background: Assessing functional and cellular consequences following myocardial infarction (MI) using large animals has advantages of similarity in size, shape and coronary supply to human heart. Aim: To confirm presence of MI and detect recovery of perfusion and function following implantation of ovine bone-marrow derived mesenchymal stem cells (MSC) using intra-myocardial (1 M ) and intra-coronary (I C ) methods. Methods: Eighteen ewes (wt: 45-50 k g, LV-EDV: 80-90 m L) included, with 10 completing protocol (3=control, 4= IM , 3= IC ). MlBI MPI SPECT/CT performed at baseline, 5-7 days post induction of Ml and 6 weeks post cellular therapy with male MSCs. At completion, sheep sacrificed and heart slices reviewed microscopically to confirm Ml, assess neovascularisation and correlate with MPI findings. MPI studies reconstructed using OSEM CT-based AC and analysed using QPS/QGS software. Calculation of Recovery Difference (RD%), Recovery Ratio (RR) and relative change to baseline determined for each study and per segment per study. Results: M I confirmed in 10 of 12 studies (I showed no perfusion abnormality, another pre-existing defect), confirmed anatomically by identification of fibrous scar tissue with lymphoid aggregates, histiocytes and calcium deposits. Reduction in perfusion was 14% to 48%. No improvement in perfusion seen in control (RR=0.8, RD=-16.9) and IC (RR=0.9, RD=-7.1) studies. Significant reperfusion seen on 1 M studies, with RR=1.5, RD=1.1 and perfusion recovery 8%, around periphery of infarct zone. Conclusions: Presence of acute Ml identified on MlBl MPI SPECT/CT correlates with anatomical findings. Improvement in perfusion and function at infarct zone seen using 1 M method of MSC implantation, correlating with significant neovascularisation identified microscopically.

  17. Epigenetics and Cellular Metabolism

    Directory of Open Access Journals (Sweden)

    Wenyi Xu

    2016-01-01

    Full Text Available Living eukaryotic systems evolve delicate cellular mechanisms for responding to various environmental signals. Among them, epigenetic machinery (DNA methylation, histone modifications, microRNAs, etc. is the hub in transducing external stimuli into transcriptional response. Emerging evidence reveals the concept that epigenetic signatures are essential for the proper maintenance of cellular metabolism. On the other hand, the metabolite, a main environmental input, can also influence the processing of epigenetic memory. Here, we summarize the recent research progress in the epigenetic regulation of cellular metabolism and discuss how the dysfunction of epigenetic machineries influences the development of metabolic disorders such as diabetes and obesity; then, we focus on discussing the notion that manipulating metabolites, the fuel of cell metabolism, can function as a strategy for interfering epigenetic machinery and its related disease progression as well.

  18. The Listeria monocytogenes Bile Stimulon under Acidic Conditions Is Characterized by Strain-Specific Patterns and the Upregulation of Motility, Cell Wall Modification Functions, and the PrfA Regulon

    Science.gov (United States)

    Guariglia-Oropeza, Veronica; Orsi, Renato H.; Guldimann, Claudia; Wiedmann, Martin; Boor, Kathryn J.

    2018-01-01

    Listeria monocytogenes uses a variety of transcriptional regulation strategies to adapt to the extra-host environment, the gastrointestinal tract, and the intracellular host environment. While the alternative sigma factor SigB has been proposed to be a key transcriptional regulator that facilitates L. monocytogenes adaptation to the gastrointestinal environment, the L. monocytogenes' transcriptional response to bile exposure is not well-understood. RNA-seq characterization of the bile stimulon was performed in two L. monocytogenes strains representing lineages I and II. Exposure to bile at pH 5.5 elicited a large transcriptomic response with ~16 and 23% of genes showing differential transcription in 10403S and H7858, respectively. The bile stimulon includes genes involved in motility and cell wall modification mechanisms, as well as genes in the PrfA regulon, which likely facilitate survival during the gastrointestinal stages of infection that follow bile exposure. The fact that bile exposure induced the PrfA regulon, but did not induce further upregulation of the SigB regulon (beyond that expected by exposure to pH 5.5), suggests a model where at the earlier stages of gastrointestinal infection (e.g., acid exposure in the stomach), SigB-dependent gene expression plays an important role. Subsequent exposure to bile induces the PrfA regulon, potentially priming L. monocytogenes for subsequent intracellular infection stages. Some members of the bile stimulon showed lineage- or strain-specific distribution when 27 Listeria genomes were analyzed. Even though sigB null mutants showed increased sensitivity to bile, the SigB regulon was not found to be upregulated in response to bile beyond levels expected by exposure to pH 5.5. Comparison of wildtype and corresponding ΔsigB strains newly identified 26 SigB-dependent genes, all with upstream putative SigB-dependent promoters. PMID:29467736

  19. Evidence that the tri-cellular metabolism of N-acetylaspartate functions as the brain's "operating system": how NAA metabolism supports meaningful intercellular frequency-encoded communications.

    Science.gov (United States)

    Baslow, Morris H

    2010-11-01

    N-acetylaspartate (NAA), an acetylated derivative of L-aspartate (Asp), and N-acetylaspartylglutamate (NAAG), a derivative of NAA and L-glutamate (Glu), are synthesized by neurons in brain. However, neurons cannot catabolize either of these substances, and so their metabolism requires the participation of two other cell types. Neurons release both NAA and NAAG to extra-cellular fluid (ECF) upon stimulation, where astrocytes, the target cells for NAAG, hydrolyze it releasing NAA back into ECF, and oligodendrocytes, the target cells for NAA, hydrolyze it releasing Asp to ECF for recycling to neurons. This sequence is unique as it is the only known amino acid metabolic cycle in brain that requires three cell types for its completion. The results of this cycling are two-fold. First, neuronal metabolic water is transported to ECF for its removal from brain. Second, the rate of neuronal activity is coupled with focal hyperemia, providing stimulated neurons with the energy required for transmission of meaningful frequency-encoded messages. In this paper, it is proposed that the tri-cellular metabolism of NAA functions as the "operating system" of the brain, and is essential for normal cognitive and motor activities. Evidence in support of this hypothesis is provided by the outcomes of two human inborn errors in NAA metabolism.

  20. Phosphorylation and cellular function of the human Rpa2 N-terminus in the budding yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Ghospurkar, Padmaja L; Wilson, Timothy M; Liu, Shengqin; Herauf, Anna; Steffes, Jenna; Mueller, Erica N; Oakley, Gregory G; Haring, Stuart J

    2015-02-01

    Maintenance of genome integrity is critical for proper cell growth. This occurs through accurate DNA replication and repair of DNA lesions. A key factor involved in both DNA replication and the DNA damage response is the heterotrimeric single-stranded DNA (ssDNA) binding complex Replication Protein A (RPA). Although the RPA complex appears to be structurally conserved throughout eukaryotes, the primary amino acid sequence of each subunit can vary considerably. Examination of sequence differences along with the functional interchangeability of orthologous RPA subunits or regions could provide insight into important regions and their functions. This might also allow for study in simpler systems. We determined that substitution of yeast Replication Factor A (RFA) with human RPA does not support yeast cell viability. Exchange of a single yeast RFA subunit with the corresponding human RPA subunit does not function due to lack of inter-species subunit interactions. Substitution of yeast Rfa2 with domains/regions of human Rpa2 important for Rpa2 function (i.e., the N-terminus and the loop 3-4 region) supports viability in yeast cells, and hybrid proteins containing human Rpa2 N-terminal phospho-mutations result in similar DNA damage phenotypes to analogous yeast Rfa2 N-terminal phospho-mutants. Finally, the human Rpa2 N-terminus (NT) fused to yeast Rfa2 is phosphorylated in a manner similar to human Rpa2 in human cells, indicating that conserved kinases recognize the human domain in yeast. The implication is that budding yeast represents a potential model system for studying not only human Rpa2 N-terminal phosphorylation, but also phosphorylation of Rpa2 N-termini from other eukaryotic organisms. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Drosophila atonal fully rescues the phenotype of Math1 null mice: new functions evolve in new cellular contexts

    Science.gov (United States)

    Wang, Vincent Y.; Hassan, Bassem A.; Bellen, Hugo J.; Zoghbi, Huda Y.

    2002-01-01

    Many genes share sequence similarity between species, but their properties often change significantly during evolution. For example, the Drosophila genes engrailed and orthodenticle and the onychophoran gene Ultrabithorax only partially substitute for their mouse or Drosophila homologs. We have been analyzing the relationship between atonal (ato) in the fruit fly and its mouse homolog, Math1. In flies, ato acts as a proneural gene that governs the development of chordotonal organs (CHOs), which serve as stretch receptors in the body wall and joints and as auditory organs in the antennae. In the fly CNS, ato is important not for specification but for axonal arborization. Math1, in contrast, is required for the specification of cells in both the CNS and the PNS. Furthermore, Math1 serves a role in the development of secretory lineage cells in the gut, a function that does not parallel any known to be served by ato. We wondered whether ato and Math1 might be more functionally homologous than they appear, so we expressed Math1 in ato mutant flies and ato in Math1 null mice. To our surprise, the two proteins are functionally interchangeable.

  2. A transposon mutant library of Bacillus cereus ATCC 10987 reveals novel genes required for biofilm formation and implicates motility as an important factor for pellicle-biofilm formation.

    Science.gov (United States)

    Okshevsky, Mira; Louw, Matilde Greve; Lamela, Elena Otero; Nilsson, Martin; Tolker-Nielsen, Tim; Meyer, Rikke Louise

    2018-04-01

    Bacillus cereus is one of the most common opportunistic pathogens causing foodborne illness, as well as a common source of contamination in the dairy industry. B. cereus can form robust biofilms on food processing surfaces, resulting in food contamination due to shedding of cells and spores. Despite the medical and industrial relevance of this species, the genetic basis of biofilm formation in B. cereus is not well studied. In order to identify genes required for biofilm formation in this bacterium, we created a library of 5000 +  transposon mutants of the biofilm-forming strain B. cereusATCC 10987, using an unbiased mariner transposon approach. The mutant library was screened for the ability to form a pellicle biofilm at the air-media interface, as well as a submerged biofilm at the solid-media interface. A total of 91 genes were identified as essential for biofilm formation. These genes encode functions such as chemotaxis, amino acid metabolism and cellular repair mechanisms, and include numerous genes not previously known to be required for biofilm formation. Although the majority of disrupted genes are not directly responsible for motility, further investigations revealed that the vast majority of the biofilm-deficient mutants were also motility impaired. This observation implicates motility as a pivotal factor in the formation of a biofilm by B. cereus. These results expand our knowledge of the fundamental molecular mechanisms of biofilm formation by B. cereus. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  3. Symbiosis and the origin of eukaryotic motility

    Science.gov (United States)

    Margulis, L.; Hinkle, G.

    1991-01-01

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

  4. Esophageal motility abnormalities in gastroesophageal reflux disease

    Science.gov (United States)

    Martinucci, Irene; de Bortoli, Nicola; Giacchino, Maria; Bodini, Giorgia; Marabotto, Elisa; Marchi, Santino; Savarino, Vincenzo; Savarino, Edoardo

    2014-01-01

    Esophageal motility abnormalities are among the main factors implicated in the pathogenesis of gastroesophageal reflux disease. The recent introduction in clinical and research practice of novel esophageal testing has markedly improved our understanding of the mechanisms contributing to the development of gastroesophageal reflux disease, allowing a better management of patients with this disorder. In this context, the present article intends to provide an overview of the current literature about esophageal motility dysfunctions in patients with gastroesophageal reflux disease. Esophageal manometry, by recording intraluminal pressure, represents the gold standard to diagnose esophageal motility abnormalities. In particular, using novel techniques, such as high resolution manometry with or without concurrent intraluminal impedance monitoring, transient lower esophageal sphincter (LES) relaxations, hypotensive LES, ineffective esophageal peristalsis and bolus transit abnormalities have been better defined and strongly implicated in gastroesophageal reflux disease development. Overall, recent findings suggest that esophageal motility abnormalities are increasingly prevalent with increasing severity of reflux disease, from non-erosive reflux disease to erosive reflux disease and Barrett’s esophagus. Characterizing esophageal dysmotility among different subgroups of patients with reflux disease may represent a fundamental approach to properly diagnose these patients and, thus, to set up the best therapeutic management. Currently, surgery represents the only reliable way to restore the esophagogastric junction integrity and to reduce transient LES relaxations that are considered to be the predominant mechanism by which gastric contents can enter the esophagus. On that ground, more in depth future studies assessing the pathogenetic role of dysmotility in patients with reflux disease are warranted. PMID:24868489

  5. Asian Motility Studies in Irritable Bowel Syndrome

    OpenAIRE

    Lee, Oh Young

    2010-01-01

    Altered motility remains one of the important pathophysiologic factors in patients with irritable bowel syndrome (IBS) who commonly complain of abdominal pain and stool changes such as diarrhea and constipation. The prevalence of IBS has increased among Asian populations these days. Gastrointestinal (GI) physiology may vary between Asian and Western populations because of differences in diets, socio-cultural backgrounds, and genetic factors. The characteristics and differences of GI dysmotili...

  6. Nested cellular automata

    International Nuclear Information System (INIS)

    Quasthoff, U.

    1985-07-01

    Cellular automata by definition consist of a finite or infinite number of cells, say of unit length, with each cell having the same transition function. These cells are usually considered as the smallest elements and so the space filled with these cells becomes discrete. Nevertheless, large pictures created by such cellular automata look very fractal. So we try to replace each cell by a couple of smaller cells, which have the same transition functions as the large ones. There are automata where this replacement does not destroy the macroscopic structure. In these cases this nesting process can be iterated. The paper contains large classes of automata with the above properties. In the case of one dimensional automata with two states and next neighbour interaction and a nesting function of the same type a complete classification is given. (author)

  7. Motile hepatocellular carcinoma cells preferentially secret sugar metabolism regulatory proteins via exosomes.

    Science.gov (United States)

    Zhang, Jing; Lu, Shaohua; Zhou, Ye; Meng, Kun; Chen, Zhipeng; Cui, Yizhi; Shi, Yunfeng; Wang, Tong; He, Qing-Yu

    2017-07-01

    Exosomes are deliverers of critically functional proteins, capable of transforming target cells in numerous cancers, including hepatocellular carcinoma (HCC). We hypothesize that the motility of HCC cells can be featured by comparative proteome of exosomes. Hence, we performed the super-SILAC-based MS analysis on the exosomes secreted by three human HCC cell lines, including the non-motile Hep3B cell, and the motile 97H and LM3 cells. More than 1400 exosomal proteins were confidently quantified in each MS analysis with highly biological reproducibility. We justified that 469 and 443 exosomal proteins represented differentially expressed proteins (DEPs) in the 97H/Hep3B and LM3/Hep3B comparisons, respectively. These DEPs focused on sugar metabolism-centric canonical pathways per ingenuity pathway analysis, which was consistent with the gene ontology analysis on biological process enrichment. These pathways included glycolysis I, gluconeogenesis I and pentose phosphate pathways; and the DEPs enriched in these pathways could form a tightly connected network. By analyzing the relative abundance of proteins and translating mRNAs, we found significantly positive correlation between exosomes and cells. The involved exosomal proteins were again focusing on sugar metabolism. In conclusion, motile HCC cells tend to preferentially export more sugar metabolism-associated proteins via exosomes that differentiate them from non-motile HCC cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. What is the real impairment on esophageal motility in patients with gastroesophageal reflux disease?

    Science.gov (United States)

    Falcão, Angela; Nasi, Ary; Brandão, Jeovana; Sallum, Rubens; Cecconello, Ivan

    2013-04-01

    Impairment of esophageal motility is a common finding in patients with gastroesophageal reflux disease (GERD) as reduced lower esophageal sphincter (LES) basal pressure. A very low LES pressure might facilitate the occurrence of more gastroesophageal reflux whereas abnormal esophageal peristalsis may contribute to impaired esophageal clearance after reflux. Evaluate the esophageal motor function of the lower esophageal sphincter and esophageal body in the various forms of gastroesophageal reflux disease. The manometrics records of 268 patients, who had evaluation of the esophageal motility as part of the diagnostic gastroesophageal reflux disease were split into four groups, as follows: 33 patients who had no esophagitis; 92 patients who had erosive esophagitis; 101 patients who had short Barrett's esophagus and 42 patients who had long Barrett's esophagus. The group who had long Barrett's esophagus showed smaller mean LES pressure and higher percentage of marked LES hypotonia; in the distal segment of the esophageal body the this group showed higher percentage of marked hypocontractility of the distal segment (disorders. The most intense esophageal motility disorders and lower pressure of lower esophageal sphincter were noted in the group with long Barrett's esophagus. Those with reflux esophagitis and short Barrett's esophagus had esophageal motility impairment, intermediate among patients with esophagitis and long Barrett's esophagus. Patients with typical symptoms of gastroesophageal reflux but without esophagitis by endoscopy study showed no impairment of esophageal motility.

  9. Sorbitol Can Fuel Mouse Sperm Motility and Protein Tyrosine Phosphorylation via Sorbitol Dehydrogenase1

    Science.gov (United States)

    Cao, Wenlei; Aghajanian, Haig K.; Haig-Ladewig, Lisa A.; Gerton, George L.

    2008-01-01

    Energy sources that can be metabolized to yield ATP are essential for normal sperm functions such as motility. Two major monosaccharides, sorbitol and fructose, are present in semen. Furthermore, sorbitol dehydrogenase (SORD) can convert sorbitol to fructose, which can then be metabolized via the glycolytic pathway in sperm to make ATP. Here we characterize Sord mRNA and SORD expression during mouse spermatogenesis and examine the ability of sorbitol to support epididymal sperm motility and tyrosine phosphorylation. Sord mRNA levels increased during the course of spermatogenic differentiation. SORD protein, however, was first detected at the condensing spermatid stage. By indirect immunofluorescence, SORD was present along the length of the flagella of caudal epididymal sperm. Furthermore, immunoelectron microscopy showed that SORD was associated with mitochondria and the plasma membranes of sperm. Sperm incubated with sorbitol maintained motility, indicating that sorbitol was utilized as an energy source. Sorbitol, as well as glucose and fructose, were not essential to induce hyperactive motility. Protein tyrosine phosphorylation increased in a similar manner when sorbitol was substituted for glucose in the incubation medium used for sperm capacitation. These results indicate that sorbitol can serve as an alternative energy source for sperm motility and protein tyrosine phosphorylation. PMID:18799757

  10. PIKfyve mediates the motility of late endosomes and lysosomes in neuronal dendrites.

    Science.gov (United States)

    Tsuruta, Fuminori; Dolmetsch, Ricardo E

    2015-09-25

    The endosome/lysosome system in the nervous system is critically important for a variety of neuronal functions such as neurite outgrowth, retrograde transport, and synaptic plasticity. In neurons, the endosome/lysosome system is crucial for the activity-dependent internalization of membrane proteins and contributes to the regulation of lipid level on the plasma membrane. Although homeostasis of membrane dynamics plays important roles in the properties of central nervous systems, it has not been elucidated how endosome/lysosome system is regulated. Here, we report that phosphatidylinositol 3-phosphate 5-kinase (PIKfyve) mediates the motility of late endosomes and lysosomes in neuronal dendrites. Endosomes and lysosomes are highly motile in resting neurons, however knockdown of PIKfyve led to a significant reduction in late endosomes and lysosomes motility. We also found that vesicle acidification is crucial for their motility and PIKfyve is associated with this process indirectly. These data suggest that PIKfyve mediates vesicle motility through the regulation of vesicle integrity in neurons. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. RELATIONSHIP BETWEEN LEVEL OF COPPER IN BOVINE SEMINAL PLASMA AND SPERMATOZOA MOTILITY

    Directory of Open Access Journals (Sweden)

    Zuzana Kňažická

    2013-02-01

    Full Text Available The aim of this study was to evaluate relationship between copper (Cu concentration of bovine seminal plasma and spermatozoa motility. Semen samples were collected from 13 breeding bulls. The motility analysis was carried out using the Computer Assisted Sperm Analysis (CASA system. The mean value for the percentage of motile spermatozoa (MOT was 92.46±3.99% and the progressive motility of the spermatozoa (PROG as 90.23±4.02%. The seminal plasma Cu concentrations were analyzed by UV/VIS spectrophotometry. The total Cu concentration of the seminal plasma was 4.28±1.47 μM/L. The correlation analysis revealed a strong negative correlation between MOT and seminal plasma Cu concentration (rp=-0.781; P<0.01 as well as between PROG and Cu content in the seminal plasma (rp=-0.726; P<0.01. The data obtained from this study clearly indicated that concentration of copper in seminal plasma negatively affects the spermatozoa motility parameters and subsequently might cause reproductive alteration in male sexual functions.

  12. The effect of Tribulus terrestris extract on motility and viability of human sperms after cryopreservation.

    Science.gov (United States)

    Asadmobini, Atefeh; Bakhtiari, Mitra; Khaleghi, Sara; Esmaeili, Farzaneh; Mostafaei, Ali

    2017-04-01

    Semen cryopreservation produces significant amounts of reactive oxygen species (ROS), which may lead to impairment of sperm morphology, function, and ultimately, male fertility. Since Tribulus terrestris has antioxidant and free-radical-scavenging properties, this study aims to reveal the effect of the Tribulus terrestris extract on motility and vitality of human sperms after cryopreservation. Semen specimens from 80 healthy volunteers were divided into eight groups: fresh control (group I), freeze control (group II), groups III, IV, and V, which had 20, 40, and 50 μg/mL doses of Tribulus terrestris extract added before cryopreservation, and groups VI, VII, and VIII, which were supplemented by these extract doses after the freeze-thaw process. To evaluate the effects of the Tribulus terrestris extract, the semen samples were incubated with the extract and evaluated with a light microscope for motility and viability. After cryopreservation, a significant improvement in spermatozoa viability was observed in group VII. In groups VII and VIII, motility, according to World Health Organization (WHO) criteria, increased considerably (p Tribulus terrestris, which improves human sperm motility and viability, may be due to its antioxidant properties. On the basis of the results, the researchers concluded that Tribulus terrestris can be used as a safe therapeutic alternative to current modalities for the management of motility dysfunction in males. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Surface Topography Hinders Bacterial Surface Motility.

    Science.gov (United States)

    Chang, Yow-Ren; Weeks, Eric R; Ducker, William A

    2018-03-21

    We demonstrate that the surface motility of the bacterium, Pseudomonas aeruginosa, is hindered by a crystalline hemispherical topography with wavelength in the range of 2-8 μm. The motility was determined by the analysis of time-lapse microscopy images of cells in a flowing growth medium maintained at 37 °C. The net displacement of bacteria over 5 min is much lower on surfaces containing 2-8 μm hemispheres than on flat topography, but displacement on the 1 μm hemispheres is not lower. That is, there is a threshold between 1 and 2 μm for response to the topography. Cells on the 4 μm hemispheres were more likely to travel parallel to the local crystal axis than in other directions. Cells on the 8 μm topography were less likely to travel across the crowns of the hemispheres and were also more likely to make 30°-50° turns than on flat surfaces. These results show that surface topography can act as a significant barrier to surface motility and may therefore hinder surface exploration by bacteria. Because surface exploration can be a part of the process whereby bacteria form colonies and seek nutrients, these results help to elucidate the mechanism by which surface topography hinders biofilm formation.

  14. Endocrine Disrupters in Human Blood and Breast Milk: Extraction Methodologies, Cellular Uptake and Effect on Key Nuclear Receptor Functions

    DEFF Research Database (Denmark)

    Hjelmborg, Philip Sebastian

    2010-01-01

    -products from incineration plants, plastic additives, technical industry products, pesticides from the farming industry and detergent degradation products. Many of these substances can interfere with the hormonal system in organisms. The common name for these compounds is endocrine disrupters (EDCs). Some EDCs...... are persistent to degradation and are also called persistent organic pollutants (POPs). Endocrine disrupters are compounds that can interfere with an organism’s hormone system by interacting with the hormone receptors. Many of an organism’s body functions are controlled by interactions between hormones...

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

    Directory of Open Access Journals (Sweden)

    Gevaert Kris

    2006-06-01

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

  16. The effect of natural and synthetic fatty acids on membrane structure, microdomain organization, cellular functions and human health.

    Science.gov (United States)

    Ibarguren, Maitane; López, David J; Escribá, Pablo V

    2014-06-01

    This review deals with the effects of synthetic and natural fatty acids on the biophysical properties of membranes, and on their implication on cell function. Natural fatty acids are constituents of more complex lipids, like triacylglycerides or phospholipids, which are used by cells to store and obtain energy, as well as for structural purposes. Accordingly, natural and synthetic fatty acids may modify the structure of the lipid membrane, altering its microdomain organization and other physical properties, and provoking changes in cell signaling. Therefore, by modulating fatty acids it is possible to regulate the structure of the membrane, influencing the cell processes that are reliant on this structure and potentially reverting pathological cell dysfunctions that may provoke cancer, diabetes, hypertension, Alzheimer's and Parkinson's disease. The so-called Membrane Lipid Therapy offers a strategy to regulate the membrane composition through drug administration, potentially reverting pathological processes by re-adapting cell membrane structure. Certain fatty acids and their synthetic derivatives are described here that may potentially be used in such therapies, where the cell membrane itself can be considered as a target to combat disease. This article is part of a Special Issue entitled: Membrane Structure and Function: Relevance in the Cell's Physiology, Pathology and Therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. The Fanconi anemia proteins FAA and FAC function in different cellular compartments to protect against cross-linking agent cytotoxicity.

    Science.gov (United States)

    Kruyt, F A; Youssoufian, H

    1998-10-01

    Fanconi anemia (FA) is an autosomal recessive disease characterized by chromosomal instability, bone marrow failure, and a high risk of developing malignancies. Although the disorder is genetically heterogeneous, all FA cells are defined by their sensitivity to the apoptosis-inducing effect of cross-linking agents, such as mitomycin C (MMC). The cloned FA disease genes, FAC and FAA, encode proteins with no homology to each other or to any known protein. We generated a highly specific antibody against FAA and found the protein in both the cytoplasm and nucleus of mammalian cells. By subcellular fractionation, FAA is also associated with intracellular membranes. To identify the subcellular compartment that is relevant for FAA activity, we appended nuclear export and nuclear localization signals to the carboxy terminus of FAA and enriched its localization in either the cytoplasm or the nucleus. Nuclear localization of FAA was both necessary and sufficient to correct MMC sensitivity in FA-A cells. In addition, we found no evidence for an interaction between FAA and FAC either in vivo or in vitro. Together with a previous finding that FAC is active in the cytoplasm but not in the nucleus, our results indicate that FAA and FAC function in separate subcellular compartments. Thus, FAA and FAC, if functionally linked, are more likely to be in a linear pathway rather than form a macromolecular complex to protect against cross-linker cytotoxicity.

  18. Soluble extracellular matrix metalloproteinase inducer (EMMPRIN, EMN) regulates cancer-related cellular functions by homotypic interactions with surface CD147.

    Science.gov (United States)

    Knutti, Nadine; Kuepper, Michael; Friedrich, Karlheinz

    2015-11-01

    EMMPRIN (extracellular matrix metalloproteinase inducer) is a widely expressed glycoprotein and a member of the immunoglobulin superfamily which exists in both a membrane-spanning and a soluble form. Homotypic interactions of EMMPRIN underlie its multiple roles in normal development and pathological situations such as viral infections, Alzheimer's disease and cancer. This study employed a recombinant soluble, fully glycosylated EMMPRIN domain (rhsEMN) as a tool to characterize the structural basis of EMMPRIN-EMMPRIN receptor (EMNR) contacts and their functional effects on MCF-7 breast carcinoma cells. rhsEMN did not form dimers in solution but bound to surface EMMPRIN (EMN) on MCF-7 cells with high affinity and was readily internalized. The interaction interface for the homotypic contact was localized to the N-terminal Ig domain. rhsEMN exerted a stimulatory effect on proliferation of MCF-7 cells whereas it reduced cell migration in a dose-dependent manner. These effects were accompanied by an upregulation of endogenous EMMPRIN as well as of matrix metalloproteinase-14 (MMP-14), a membrane-bound protease involved in the extracellular release of soluble EMMPRIN, indicating a regulatory feedback mechanism. The proliferation-promoting activity of rhsEMN was mimicked by a novel functional antibody directed to EMMPRIN, underscoring that crosslinking of cell surface EMMPRIN (EMNR) is crucial for eliciting intracellular signalling. Addressing malignancy-related signal transduction in HEK-293 cells, we could show that rhsEMN triggers the oncogenic Wnt pathway. © 2015 FEBS.

  19. Clinical and pathogenetic variants of antroduodenal motility disorders in children and their medicinal correction

    Directory of Open Access Journals (Sweden)

    A. I. Khavkin

    2015-01-01

    Full Text Available Antroduodenal motility disorder is a major component of the pathogenesis of most diseases of the upper gastrointestinal tract. Motility regulation is a complex process and it is accomplished by complex balanced neurohumoral mechanisms and depends on the chemical composition of the chyme and on the change in the cyclic membrane potential — slow waves that generate myogenic pacemakers. The electrical activity of the stomach and duodenum may be assessed by electrogastroenterography that shows the motor evacutory function of these digestive tract segments and helps choose therapy for its disorders.

  20. Lysine-functionalized nanodiamonds as gene carriers: development of stable colloidal dispersion for in vitro cellular uptake studies and siRNA delivery application

    Science.gov (United States)

    Alwani, Saniya; Kaur, Randeep; Michel, Deborah; Chitanda, Jackson M; Verrall, Ronald E; Karunakaran, Chithra; Badea, Ildiko

    2016-01-01

    Purpose Nanodiamonds (NDs) are emerging as an attractive tool for gene therapeutics. To reach their full potential for biological application, NDs should maintain their colloidal stability in biological milieu. This study describes the behavior of lysine-functionalized ND (lys-ND) in various dispersion media, with an aim to limit aggregation and improve the colloidal stability of ND-gene complexes called diamoplexes. Furthermore, cellular and macromolecular interactions of lys-NDs are also analyzed in vitro to establish the understanding of ND-mediated gene transfer in cells. Methods lys-NDs were synthesized earlier through covalent conjugation of lysine amino acid to carboxylated NDs surface generated through re-oxidation in strong oxidizing acids. In this study, dispersions of lys-NDs were prepared in various media, and the degree of sedimentation was monitored for 72 hours. Particle size distributions and zeta potential measurements were performed for a period of 25 days to characterize the physicochemical stability of lys-NDs in the medium. The interaction profile of lys-NDs with fetal bovine serum showed formation of a protein corona, which was evaluated by size and charge distribution measurements. Uptake of lys-NDs in cervical cancer cells was analyzed by scanning transmission X-ray microscopy, flow cytometry, and confocal microscopy. Cellular uptake of diamoplexes (complex of lys-NDs with small interfering RNA) was also analyzed using flow cytometry. Results Aqueous dispersion of lys-NDs showed minimum sedimentation and remained stable over a period of 25 days. Size distributions showed good stability, remaining under 100 nm throughout the testing period. A positive zeta potential of >+20 mV indicated a preservation of surface charges. Size distribution and zeta potential changed for lys-NDs after incubation with blood serum, suggesting an interaction with biomolecules, mainly proteins, and a possible formation of a protein corona. Cellular internalization

  1. Lysine-functionalized nanodiamonds as gene carriers: development of stable colloidal dispersion for in vitro cellular uptake studies and siRNA delivery application.

    Science.gov (United States)

    Alwani, Saniya; Kaur, Randeep; Michel, Deborah; Chitanda, Jackson M; Verrall, Ronald E; Karunakaran, Chithra; Badea, Ildiko

    2016-01-01

    Nanodiamonds (NDs) are emerging as an attractive tool for gene therapeutics. To reach their full potential for biological application, NDs should maintain their colloidal stability in biological milieu. This study describes the behavior of lysine-functionalized ND (lys-ND) in various dispersion media, with an aim to limit aggregation and improve the colloidal stability of ND-gene complexes called diamoplexes. Furthermore, cellular and macromolecular interactions of lys-NDs are also analyzed in vitro to establish the understanding of ND-mediated gene transfer in cells. lys-NDs were synthesized earlier through covalent conjugation of lysine amino acid to carboxylated NDs surface generated through re-oxidation in strong oxidizing acids. In this study, dispersions of lys-NDs were prepared in various media, and the degree of sedimentation was monitored for 72 hours. Particle size distributions and zeta potential measurements were performed for a period of 25 days to characterize the physicochemical stability of lys-NDs in the medium. The interaction profile of lys-NDs with fetal bovine serum showed formation of a protein corona, which was evaluated by size and charge distribution measurements. Uptake of lys-NDs in cervical cancer cells was analyzed by scanning transmission X-ray microscopy, flow cytometry, and confocal microscopy. Cellular uptake of diamoplexes (complex of lys-NDs with small interfering RNA) was also analyzed using flow cytometry. Aqueous dispersion of lys-NDs showed minimum sedimentation and remained stable over a period of 25 days. Size distributions showed good stability, remaining under 100 nm throughout the testing period. A positive zeta potential of >+20 mV indicated a preservation of surface charges. Size distribution and zeta potential changed for lys-NDs after incubation with blood serum, suggesting an interaction with biomolecules, mainly proteins, and a possible formation of a protein corona. Cellular internalization of lys-NDs was confirmed

  2. Function of mammalian genes regulation cellular growth; Saibo zoshoku wo seigyosuru dobutsu saibo idenshi no kino kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, K. [Nagoya University, Nagoya (Japan)

    1995-12-15

    Intracellular signaling from receptor tyrosine kindles in mammalian cells results in activation of a signal cascade that includes the guanine nucleotide binding protein Ras and the protein kinases Raf, MEK [Mitogen activated protein kindle (MAPK) or Extracellular signal regulated kinase (ERK) kinase] and MAPK. MAPK activation that is dependent on the coupling of Ras and Raf was reconstituted in yeast. Yeast genes were isolated that, when overexpressed, enhanced the function of Raf. One of them is identical to BMH 1, which encodes a protein similar to members of the mammalian 14-3-3 family. Bacterially synthesized mammalian 14-3-3 protein stimulated the activity of Raf prepared from yeast cells expressing c-Raf-1. Thus, the 14-3-3 protein may participate in or be required for activation of Raf. 9 refs., 2 figs.

  3. Treatment with 1,25-dihydroxyvitamin D3 reduces impairment of human osteoblast functions during cellular aging in culture

    DEFF Research Database (Denmark)

    Kveiborg, M.; Rattan, Suresh; Eriksen, E.F.

    2001-01-01

    is due to impaired responsiveness to calcitriol known to be important for the regulation of biological activities of the osteoblasts. Thus, we examined changes in vitamin D receptor (VDR) system and the osteoblastic responses to calcitriol treatment during in vitro osteoblast aging. We found no change...... in the amount of VDR at either steady state mRNA level or protein level with increasing in vitro osteoblast age and examination of VDR localization, nuclear translocation and DNA binding activity revealed no in vitro age-related changes. Furthermore, calcitriol (10(-8)M) treatment of early-passage osteoblastic......Adequate responses to various hormones, such as 1,25-dihydroxyvitamin D(3) (calcitriol) are a prerequisite for optimal osteoblast functions. We have previously characterized several human diploid osteoblastic cell lines that exhibit typical in vitro aging characteristics during long...

  4. Mimicking the phosphorylation of Rsp5 in PKA site T761 affects its function and cellular localization.

    Science.gov (United States)

    Jastrzebska, Zaneta; Kaminska, Joanna; Chelstowska, Anna; Domanska, Anna; Rzepnikowska, Weronika; Sitkiewicz, Ewa; Cholbinski, Piotr; Gourlay, Campbell; Plochocka, Danuta; Zoladek, Teresa

    2015-12-01

    Rsp5 ubiquitin ligase belongs to the Nedd4 family of proteins, which affect a wide variety of processes in the cell. Here we document that Rsp5 shows several phosphorylated variants of different mobility and the migration of the phosphorylated forms of Rsp5 was faster for the tpk1Δ tpk3Δ mutant devoid of two alternative catalytic subunits of protein kinase A (PKA), indicating that PKA possibly phosphorylates Rsp5 in vivo. We demonstrated by immunoprecipitation and Western blot analysis of GFP-HA-Rsp5 protein using the anti-phospho PKA substrate antibody that Rsp5 is phosphorylated in PKA sites. Rsp5 contains the sequence 758-RRFTIE-763 with consensus RRXS/T in the catalytic HECT domain and four other sites with consensus RXXS/T, which might be phosphorylated by PKA. The strain bearing the T761D substitution in Rsp5 which mimics phosphorylation grew more slowly at 28°C and did not grow at 37°C, and showed defects in pre-tRNA processing and protein sorting. The rsp5-T761D strain also demonstrated a reduced ability to form colonies, an increase in the level of reactive oxygen species (ROS) and hypersensitivity to ROS-generating agents. These results indicate that PKA may downregulate many functions of Rsp5, possibly affecting its activity. Rsp5 is found in the cytoplasm, nucleus, multivesicular body and cortical patches. The rsp5-T761D mutation led to a strongly increased cortical localization while rsp5-T761A caused mutant Rsp5 to locate more efficiently in internal spots. Rsp5-T761A protein was phosphorylated less efficiently in PKA sites under specific growth conditions. Our data suggests that Rsp5 may be phosphorylated by PKA at position T761 and that this regulation is important for its localization and function. Copyright © 2015 Elsevier GmbH. All rights reserved.

  5. Nuclear Factor 90, a cellular dsRNA binding protein inhibits the HIV Rev-export function

    Directory of Open Access Journals (Sweden)

    St-Laurent Georges

    2006-11-01

    Full Text Available Abstract Background The HIV Rev protein is known to facilitate export of incompletely spliced and unspliced viral transcripts to the cytoplasm, a necessary step in virus life cycle. The Rev-mediated nucleo-cytoplasmic transport of nascent viral transcripts, dependents on interaction of Rev with the RRE RNA structural element present in the target RNAs. The C-terminal variant of dsRNA-binding nuclear protein 90 (NF90ctv has been shown to markedly attenuate viral replication in stably transduced HIV-1 target cell line. Here we examined a mechanism of interference of viral life cycle involving Rev-NF90ctv interaction. Results Since Rev:RRE complex formations depend on protein:RNA and protein:protein interactions, we investigated whether the expression of NF90ctv might interfere with Rev-mediated export of RRE-containing transcripts. When HeLa cells expressed both NF90ctv and Rev protein, we observed that NF90ctv inhibited the Rev-mediated RNA transport. In particular, three regions of NF90ctv protein are involved in blocking Rev function. Moreover, interaction of NF90ctv with the RRE RNA resulted in the expression of a reporter protein coding sequences linked to the RRE structure. Moreover, Rev influenced the subcellular localization of NF90ctv, and this process is leptomycin B sensitive. Conclusion The dsRNA binding protein, NF90ctv competes with HIV Rev function at two levels, by competitive protein:protein interaction involving Rev binding to specific domains of NF90ctv, as well as by its binding to the RRE-RNA structure. Our results are consistent with a model of Rev-mediated HIV-1 RNA export that envisions Rev-multimerization, a process interrupted by NF90ctv.

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

    Science.gov (United States)

    Bi, Dapeng; Yang, Xingbo; Marchetti, M. Cristina; Manning, M. Lisa

    2017-01-01

    Cell motion inside dense tissues governs many biological processes, including embryonic development and cancer metastasis, and recent experiments suggest that these tissues exhibit collective glassy behavior. To make quantitative predictions about glass transitions in tissues, we study a self-propelled Voronoi (SPV) model that simultaneously captures polarized cell motility and multi-body cell-cell interactions in a confluent tissue, where there are no gaps between cells. We demonstrate that the model exhibits a jamming transition from a solid-like state to a fluid-like state that is controlled by three parameters: the single-cell motile speed, the persistence time of single-cell tracks, and a target shape index that characterizes the competition between cell-cell adhesion and cortical tension. In contrast to traditional particulate glasses, we are able to identify an experimentally accessible structural order parameter that specifies the entire jamming surface as a function of model parameters. We demonstrate that a continuum Soft Glassy Rheology model precisely captures this transition in the limit of small persistence times, and explain how it fails in the limit of large persistence times. These results provide a framework for understanding the collective solid-to-liquid transitions that have been observed in embryonic development and cancer progression, which may be associated with Epithelial-to-Mesenchymal transition in these tissues. PMID:28966874

  7. Flagellar motility is critical for Listeria monocytogenes biofilm formation.

    Science.gov (United States)

    Lemon, Katherine P; Higgins, Darren E; Kolter, Roberto

    2007-06-01

    The food-borne pathogen Listeria monocytogenes attaches to environmental surfaces and forms biofilms that can be a source of food contamination, yet little is known about the molecular mechanisms of its biofilm development. We observed that nonmotile mutants were defective in biofilm formation. To investigate how flagella might function during biofilm formation, we compared the wild type with flagellum-minus and paralyzed-flagellum mutants. Both nonmotile mutants were defective in biofilm development, presumably at an early stage, as they were also defective in attachment to glass during the first few hours of surface exposure. This attachment defect could be significantly overcome by providing exogenous movement toward the surface via centrifugation. However, this centrifugation did not restore mature biofilm formation. Our results indicate that it is flagellum-mediated motility that is critical for both initial surface attachment and subsequent biofilm formation. Also, any role for L. monocytogenes flagella as adhesins on abiotic surfaces appears to be either minimal or motility dependent under the conditions we examined.

  8. [Primary esophageal motility disorders; especially about esophageal achalasia].

    Science.gov (United States)

    Miyazaki, Tatsuya; Sohda, Makoto; Sakai, Makoto; Tanaka, Naritaka; Suzuki, Shigemasa; Yokobori, Takehiko; Inose, Takanori; Nakajima, Masanobu; Fukuchi, Minoru; Kato, Hiroyuki; Kusano, Motoyasu; Kuwano, Hiroyuki

    2011-07-01

    Esophageal motility disorders are classified primary and secondary, and primary esophageal motility disorders are classified esophageal achalasia and other diseases by manometry. An esophageal emptying disorder associated with insufficient relaxation of the lower esophageal sphincter (LES) and elimination of peristaltic waves on the esophageal body is the major abnormality of achalasia. Esophagogram, endoscopy, and manometry are used for diagnosis. As pharmacological therapy, administration of a calcium channel blocker or nitrate is useful. The pharmacological therapy is not recommended as long-term basic therapy but as a temporary treatment. At 1st, the balloon dilation method is chosen in treatment of achalasia Surgical treatment is indicated in the following cases: (1) Patients uneffected by balloon dilation, (2) Flask type with grade II to III dilation, and sigmoid type, (3) the gradual progression to the pathophysiological stage, (4) young patients, (5) complicated with esophageal cancer. Laparoscopic Heller-Dor procedure is the most popular surgical procedure, recently. It is somewhat difficult to perform surgical treatment for this functional disease. We should select the most suitable individualized treatment with efficient comprehension of the pathophysiological situation.

  9. Membrane tension and cytoskeleton organization in cell motility

    International Nuclear Information System (INIS)

    Sens, Pierre; Plastino, Julie

    2015-01-01

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

  10. Membrane tension and cytoskeleton organization in cell motility.

    Science.gov (United States)

    Sens, Pierre; Plastino, Julie

    2015-07-15

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

  11. Lipid Replacement Therapy: a Functional Food Approach with New Formulations for Reducing Cellular Oxidative Damage, Cancer-Associated Fatigue and the Adverse Effects of Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Garth L. Nicolson

    2011-04-01

    Full Text Available Backgroud:Cancer-associated fatigue and the chronic adverse effects of cancer therapy can be reduced by Lipid Replacement Therapy (LRT using membrane phospholipid mixtures given as food supplements.Methods:This is a review of the published literature on LRT and its uses.Results: LRT significantly reduced fatigue in cancer patients as well as patients suffering from chronic fatiguing illnesses and other medical conditions. It also reduced the adverse effects of chemotherapy, resulting in improvements in incidence of fatigue, nausea, diarrhea, impaired taste, constipation, insomnia and other quality of life indicators. In other diseases, such as chronic fatigue syndrome, fibromyalgia syndrome and other chronic fatiguing illnesses, LRT reduced fatigue by 35.5-43.1% in different clinical trials and increased mitochondrial function.Conclusions: LRT formulations appear to be useful as non-toxic dietary supplements for direct use or placed in functional foods to reduce fatigue and restore mitochondrial and other cellular membrane functions. Formulations of LRT phospholipids are suitable for addition to variousfood products for the treatment of a variety of chronic illnesses as well as their application inanti-aging and other health supplements and products.

  12. Natural cytolytic activity in mice with natural or induced cellular defects. I. Differential ability of in vitro interleukin-2 addition to augment natural cytolytic function

    International Nuclear Information System (INIS)

    Ades, E.W.; Hinson, A.; Butler, L.D.

    1986-01-01

    The ability of in vitro addition of recombinant interleukin 2 (rIL-2) to differentially enhance natural cytotoxicity was assessed using cells from mice with natural and induced cellular defects. In vivo treatment with most immunosuppressive or cytoreductive agents, anti-asialo-GM1 antibody, or gamma irradiation dramatically reduced in vitro cytotoxicity against natural killer (NK) sensitive targets by direct reduction in either percentage specific lysis or lytic units per spleen. In most cases, in vitro addition of rIL-2 (at concentrations causing augmented NK function in cells from naive Balb/C mice) enhanced cytotoxic activity of cells from treatment groups to a normal value but not within the rIL-2-enhanced range of nontreated animals. Additionally, cytotoxic activity of cells from animals treated with certain drugs or gamma irradiation could be augmented by rIL-2 when measured by percentage lysis but not lytic units per spleen. In vivo treatment with cyclosporin A did not affect natural cytotoxic activity and addition of rIL-2 augmented the NK activity in a similar fashion to the profile of naive cells. In experiments using cells from beige (C57Bl/6-bg) mice which have a natural defect in NK activity against YAC-1 targets, addition of rIL-2 (at concentrations causing augmented natural cytotoxic function in cells from C57Bl/6 mice) could not effectively enhance in vitro natural cytotoxic function

  13. Natural cytolytic activity in mice with natural or induced cellular defects. I. Differential ability of in vitro interleukin-2 addition to augment natural cytolytic function

    Energy Technology Data Exchange (ETDEWEB)

    Ades, E.W.; Hinson, A.; Butler, L.D.

    1986-08-01

    The ability of in vitro addition of recombinant interleukin 2 (rIL-2) to differentially enhance natural cytotoxicity was assessed using cells from mice with natural and induced cellular defects. In vivo treatment with most immunosuppressive or cytoreductive agents, anti-asialo-GM1 antibody, or gamma irradiation dramatically reduced in vitro cytotoxicity against natural killer (NK) sensitive targets by direct reduction in either percentage specific lysis or lytic units per spleen. In most cases, in vitro addition of rIL-2 (at concentrations causing augmented NK function in cells from naive Balb/C mice) enhanced cytotoxic activity of cells from treatment groups to a normal value but not within the rIL-2-enhanced range of nontreated animals. Additionally, cytotoxic activity of cells from animals treated with certain drugs or gamma irradiation could be augmented by rIL-2 when measured by percentage lysis but not lytic units per spleen. In vivo treatment with cyclosporin A did not affect natural cytotoxic activity and addition of rIL-2 augmented the NK activity in a similar fashion to the profile of naive cells. In experiments using cells from beige (C57Bl/6-bg) mice which have a natural defect in NK activity against YAC-1 targets, addition of rIL-2 (at concentrations causing augmented natural cytotoxic function in cells from C57Bl/6 mice) could not effectively enhance in vitro natural cytotoxic function.

  14. Synthesis, solubilization, and surface functionalization of highly fluorescent quantum dots for cellular targeting through a small molecule

    Science.gov (United States)

    Galloway, Justin F.

    To achieve long-term fluorescence imaging with quantum dots (QDs), a CdSe core/shell must first be synthesized. The synthesis of bright CdSe QDs is not trivial and as a consequence, the role of surfactant in nucleation and growth was investigated. It was found that the type of surfactant used, either phosphonic or fatty acid, played a pivotal role in the size of the CdSe core. The study of surfactant on CdSe synthesis, ultimately led to an electrical passivation method that utilized a short-chained phosphonic acid and highly reactive organometallic precursors to achieve high quantum yield (QY) as has been previously described. The synthesis of QDs using organometallic precursors and a phosphonic acid for passivation resulted in 4 out of 9 batches of QDs achieving QYs greater than 50% and 8 out of 9 batches with QYs greater than 35%. The synthesis of CdSe QDs was done in organic solutions rendering the surface of the particle hydrophobic. To perform cell-targeting experiments, QDs must be transferred to water. The transfer of QDs to water was successfully accomplished by using single acyl chain lipids. A systematic study of different lipid combinations and coatings demonstrated that 20-40 mol% single acyl chained lipids were able to transfer QDs to water resulting in monodispersed, stable QDs without adversely affecting the QY. The advantage to water solubilization using single acyl chain lipids is that the QD have a hydrodynamic radius less than 15 nm, QYs that can exceed 50% and additional surface functionalization can be down using the reactive sites incorporated into the lipid bilayer. QDs that are bright and stable in water were studied for the purpose of targeting G protein-coupled Receptors (GPCR). GPCRs are transmembrane receptors that internalize extracellular cues, and thus mediate signal transduction. The cyclic Adenosine Monophosphate Receptor 1 of the model organism Dictyostelium disodium was the receptor of interest. The Halo protein, a genetically

  15. Resveratrol Enhances Exercise-Induced Cellular and Functional Adaptations of Skeletal Muscle in Older Men and Women.

    Science.gov (United States)

    Alway, Stephen E; McCrory, Jean L; Kearcher, Kalen; Vickers, Austen; Frear, Benjamin; Gilleland, Diana L; Bonner, Daniel E; Thomas, James M; Donley, David A; Lively, Mathew W; Mohamed, Junaith S

    2017-11-09

    Older men (n = 12) and women (n = 18) 65-80 years of age completed 12 weeks of exercise and took either a placebo or resveratrol (RSV) (500 mg/d) to test the hypothesis that RSV treatment combined with exercise would increase mitochondrial density, muscle fatigue resistance, and cardiovascular function more than exercise alone. Contrary to our hypothesis, aerobic and resistance exercise coupled with RSV treatment did not reduce cardiovascular risk further than exercise alone. However, exercise added to RSV treatment improved the indices of mitochondrial density, and muscle fatigue resistance more than placebo and exercise treatments. In addition, subjects that were treated with RSV had an increase in knee extensor muscle peak torque (8%), average peak torque (14%), and power (14%) after training, whereas exercise did not increase these parameters in the placebo-treated older subjects. Furthermore, exercise combined with RSV significantly improved mean fiber area and total myonuclei by 45.3% and 20%, respectively, in muscle fibers from the vastus lateralis of older subjects. Together, these data indicate a novel anabolic role of RSV in exercise-induced adaptations of older persons and this suggests that RSV combined with exercise might provide a better approach for reversing sarcopenia than exercise alone. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Molecular dynamics studies of simple membrane-water interfaces: Structure and functions in the beginnings of cellular life

    Science.gov (United States)

    Pohorille, Andrew; Wilson, Michael A.

    1995-01-01

    Molecular dynamics computer simulations of the structure and functions of a simple membrane are performed in order to examine whether membranes provide an environment capable of promoting protobiological evolution. Our model membrane is composed of glycerol 1-monooleate. It is found that the bilayer surface fluctuates in time and space, occasionally creating thinning defects in the membrane. These defects are essential for passive transport of simple ions across membranes because they reduce the Born barrier to this process by approximately 40%. Negative ions are transferred across the bilayer more readily than positive ions due to favorable interactions with the electric field at the membrane-water interface. Passive transport of neutral molecules is, in general, more complex than predicted by the solubility-diffusion model. In particular, molecules which exhibit sufficient hydrophilicity and lipophilicity concentrate near membrane surfaces and experience 'interfacial resistance' to transport. The membrane-water interface forms an environment suitable for heterogeneous catalysis. Several possible mechanisms leading to an increase of reaction rates at the interface are discussed. We conclude that vesicles have many properties that make them very good candidates for earliest protocells. Some potentially fruitful directions of experimental and theoretical research on this subject are proposed.

  17. O-GlcNAcylation affects β-catenin and E-cadherin expression, cell motility and tumorigenicity of colorectal cancer.

    Science.gov (United States)

    Harosh-Davidovich, Shani Ben; Khalaila, Isam

    2018-03-01

    O-GlcNAcylation, the addition of β-N-acetylglucosamine (O-GlcNAc) moiety to Ser/Thr residues, is a sensor of the cell metabolic state. Cancer diseases such as colon, lung and breast cancer, possess deregulated O-GlcNAcylation. Studies during the last decade revealed that O-GlcNAcylation is implicated in cancer tumorigenesis and proliferation. The Wnt/β-catenin signaling pathway and cadherin-mediated adhesion are also implicated in epithelial-mesenchymal transition (EMT), a key cellular process in invasion and cancer metastasis. Often, deregulation of the Wnt pathway is caused by altered phosphorylation of its components. Specifically, phosphorylation of Ser or Thr residues of β-catenin affects its location and interaction with E-cadherin, thus facilitating cell-cell adhesion. Consistent with previous studies, the current study indicates that β-catenin is O-GlcNAcylated. To test the effect of O-GlcNAcylation on cell motility and how O-GlcNAcylation might affect β-catenin and E-cadherin functions, the enzyme machinery of O-GlcNAcylation was modulated either with chemical inhibitors or by gene silencing. When O-GlcNAcase (OGA) was inhibited, a global elevation of protein O-GlcNAcylation and increase in the expression of E-cadherin and β-catenin were noted. Concomitantly with enhanced O-GlcNAcylation, β-catenin transcriptional activity were elevated. Additionally, fibroblast cell motility was enhanced. Stable silenced cell lines with adenoviral OGA or adenoviral O-GlcNAc transferase (OGT) were established. Consistent with the results obtained by OGA chemical inhibition by TMG, OGT-silencing led to a significant reduction in β-catenin level. In vivo, murine orthotropic colorectal cancer model indicates that elevated O-GlcNAcylation leads to increased mortality rate, tumor and metastasis development. However, reduction in O-GlcNAcylation promoted survival that could be attributed to attenuated tumor and metastasis development. The results described herein provide

  18. In vivo subsurface morphological and functional cellular and subcellular imaging of the gastrointestinal tract with confocal mini-microscopy

    Institute of Scientific and Technical Information of China (English)

    Martin Goetz; Beena Memadathil; Stefan Biesterfeld; Constantin Schneider; Sebastian Gregor; Peter R Galle; Markus F Neurath; Ralf Kiesslich

    2007-01-01

    AIM: To evaluate a newly developed hand-held confocal probe for in vivo microscopic imaging of the complete gastrointestinal tract in rodents.METHODS: A novel rigid confocal probe (diameter 7 mm) was designed with optical features similar to the flexible endomicroscopy system for use in humans using a 488 nm single line laser for fluorophore excitation.Light emission was detected at 505 to 750 nm. The field of view was 475 μm × 475 μm. Optical slice thickness was 7 μm with a lateral resolution of 0.7 μm. Subsurface serial images at different depths (surface to 250 μm)were generated in real time at 1024 × 1024 pixels (0.8 frames/s) by placing the probe onto the tissue in gentle,stable contact. Tissue specimens were sampled for histopathological correlation.RESULTS: The esophagus, stomach, small and large intestine and meso, liver, pancreas and gall bladder were visualised in vivo at high resolution in n = 48 mice.Real time microscopic imaging with the confocal minimicroscopy probe was easy to achieve. The different staining protocols (fluorescein, acriflavine, FITC-labelled dextran and L. esculentum lectin) each highlighted specific aspects of the tissue, and in vivo imaging correlated excellently with conventional histology. In vivo blood flow monitoring added a functional quality to morphologic imaging.CONCLUSION: Confocal microscopy is feasible in vivo allowing the visualisation of the complete GI tract at high resolution even of subsurface tissue structures.The new confocal probe design evaluated in this study is compatible with laparoscopy and significantly expands the field of possible applications to intra-abdominal organs. It allows immediate testing of new in vivo staining and application options and therefore permits rapid transfer from animal studies to clinical use in patients.

  19. Large-scale inference of gene function through phylogenetic annotation of Gene Ontology terms: case study of the apoptosis and autophagy cellular processes.

    Science.gov (United States)

    Feuermann, Marc; Gaudet, Pascale; Mi, Huaiyu; Lewis, Suzanna E; Thomas, Paul D

    2016-01-01

    We previously reported a paradigm for large-scale phylogenomic analysis of gene families that takes advantage of the large corpus of experimentally supported Gene Ontology (GO) annotations. This 'GO Phylogenetic Annotation' approach integrates GO annotations from evolutionarily related genes across ∼100 different organisms in the context of a gene family tree, in which curators build an explicit model of the evolution of gene functions. GO Phylogenetic Annotation models the gain and loss of functions in a gene family tree, which is used to infer the functions of uncharacterized (or incompletely characterized) gene products, even for human proteins that are relatively well studied. Here, we report our results from applying this paradigm to two well-characterized cellular processes, apoptosis and autophagy. This revealed several important observations with respect to GO annotations and how they can be used for function inference. Notably, we applied only a small fraction of the experimentally supported GO annotations to infer function in other family members. The majority of other annotations describe indirect effects, phenotypes or results from high throughput experiments. In addition, we show here how feedback from phylogenetic annotation leads to significant improvements in the PANTHER trees, the GO annotations and GO itself. Thus GO phylogenetic annotation both increases the quantity and improves the accuracy of the GO annotations provided to the research community. We expect these phylogenetically based annotations to be of broad use in gene enrichment analysis as well as other applications of GO annotations.Database URL: http://amigo.geneontology.org/amigo. © The Author(s) 2016. Published by Oxford University Press.

  20. Esophagogastric junction outflow obstruction is often associated with coexistent abnormal esophageal body motility and abnormal bolus transit.

    Science.gov (United States)

    Zheng, E; Gideon, R M; Sloan, J; Katz, P O

    2017-10-01

    Currently, the diagnosis of esophageal motility disorders is in part based upon a hierarchical algorithm in which abnormalities of the esophagogastric junction (EGJ) is prioritized. An important metric in evaluating the EGJ is the integrated relaxation pressure (IRP). Patients who do not have achalasia but are found to have an elevated IRP are diagnosed with EGJ outflow obstruction. It has been our observation that a subset of these patients also has a second named motility disorder and may also have abnormal bolus transit. The aim of this study is to determine the frequency of abnormal body motility and or abnormal bolus movement in patients with EGJ outflow obstruction. Further, in an effort to evaluate the potential clinical value in measuring bolus transit as a complement to esophageal manometry, specifically in patients with EGJ outflow obstruction, we analyzed the presenting symptoms of these patients. A total of 807 patients with a mean age of 53 years completed esophageal function testing with impedance monitoring and high-resolution manometry between January 2012 and October 2016. There were 74 patients with achalasia who were excluded from the study. Of the remaining 733 patients, 138 (19%) had an elevated IRP and were given a diagnosis of EGJ outflow obstruction. Among these patients, 56 (40%) were diagnosed with an abnormal motility pattern to liquids (ineffective esophageal motility = 28, distal esophageal spasm = 19, Jackhammer = 6), of which 44 (76%) had abnormal bolus transit to liquids, viscous, or both. In contrast, there were 82 patients with EGJ outflow obstruction and normal esophageal motility, of which 33 (40%) had abnormal bolus transit. Patients with preserved esophageal motility and EGJ outflow obstruction were then evaluated. Of the 733 patients, 299 (40%) had intact esophageal motility. Of the 299 patients with normal esophageal motility, 56 patients had an elevated IRP, of which 16 (28%) had abnormal bolus transit. There were 243 (33

  1. Emergence and modular evolution of a novel motility machinery in bacteria.

    Directory of Open Access Journals (Sweden)

    Jennifer Luciano

    2011-09-01

    Full Text Available Bacteria glide across solid surfaces by mechanisms that have remained largely mysterious despite decades of research. In the deltaproteobacterium Myxococcus xanthus, this locomotion allows the formation stress-resistant fruiting bodies where sporulation takes place. However, despite the large number of genes identified as important for gliding, no specific machinery has been identified so far, hampering in-depth investigations. Based on the premise that components of the gliding machinery must have co-evolved and encode both envelope-spanning proteins and a molecular motor, we re-annotated known gliding motility genes and examined their taxonomic distribution, genomic localization, and phylogeny. We successfully delineated three functionally related genetic clusters, which we proved experimentally carry genes encoding the basal gliding machinery in M. xanthus, using genetic and localization techniques. For the first time, this study identifies structural gliding motility genes in the Myxobacteria and opens new perspectives to study the motility mechanism. Furthermore, phylogenomics provide insight into how this machinery emerged from an ancestral conserved core of genes of unknown function that evolved to gliding by the recruitment of functional modules in Myxococcales. Surprisingly, this motility machinery appears to be highly related to a sporulation system, underscoring unsuspected common mechanisms in these apparently distinct morphogenic phenomena.

  2. Cellular dosimetry

    International Nuclear Information System (INIS)

    Humm, J.L.; Chin, L.M.

    1989-01-01

    Radiation dose is a useful predictive parameter for describing radiation toxicity in conventional radiotherapy. Traditionally, in vitro radiation biology dose-effect relations are expressed in the form of cell survival curves, a semilog plot of cell survival versus dose. However, the characteristic linear or linear quadratic survival curve shape, for high- and low-LET radiations respectively, is only strictly valid when the radiation dose is uniform across the entire target population. With an external beam of 60 Co gamma rays or x-rays, a uniform field may be readily achievable. When radionuclides are incorporated into a cell milieu, several new problems emerge which can result in a departure from uniformity in energy deposition throughout a cell population. This nonuniformity can have very important consequences for the shape of the survival curve. Cases in which perturbations of source uniformity may arise include: 1. Elemental sources may equilibrate in the cell medium with partition coefficients between the extracellular, cytosol, and nuclear compartments. The effect of preferential cell internalization or binding to cell membrane of some radionuclides can increase or decrease the slope of the survival curve. 2. Radionuclides bound to antibodies, hormones, metabolite precursors, etc., may result in a source localization pattern characteristic of the carrier agent, i.e., the sources may bind to cell surface receptors or antigens, be internalized, bind to secreted antigen concentrated around a fraction of the cell population, or become directly incorporated into the cell DNA. We propose to relate the distribution of energy deposition in cell nuclei to biological correlates of cellular inactivation. The probability of each cell's survival is weighted by its individual radiation burden, and the summation of these probabilities for the cell population can be used to predict the number or fraction of cell survivors

  3. The Effect of Curcumin on Intracellular pH (pHi), Membrane Hyperpolarization and Sperm Motility.

    Science.gov (United States)

    Naz, Rajesh K

    2014-04-01

    Curcumin has shown to affect sperm motility and function in vitro and fertility in vivo. The molecular mechanism(s) by which curcumin affects sperm motility has not been delineated. Since modulation of intracellular pH (pHi) and plasma membrane polarization is involved in sperm motility, the present study was conducted to investigate the effect of curcumin on these sperm (human and murine) parameters. The effect of curcumin on sperm forward motility was examined by counting percentages of forward moving sperm. The effect of curcumin on intracellular pH (pHi) was measured by the fluorescent pH indicator 2,7-bicarboxyethyl-5,6-carboxyfluorescein-acetoxymethyl ester (BCECF-AM). The effect of curcumin on plasma membrane polarization was examined using the fluorescence sensitive dye bis (1,3-dibarbituric acid)-trimethine oxanol [DiBAC4(3)]. Curcumin caused a concentration-dependent (ppHi) in both human and mouse sperm. Curcumin induced significant (ppHi and membrane polarization that affect sperm forward motility. These exciting findings will have application in deciphering the signal transduction pathway involved in sperm motility and function and in development of a novel non-steroidal contraceptive for infertility.

  4. Receptor complementation and mutagenesis reveal SR-BI as an essential HCV entry factor and functionally imply its intra- and extra-cellular domains.

    Directory of Open Access Journals (Sweden)

    Marlène Dreux

    2009-02-01

    Full Text Available HCV entry into cells is a multi-step and slow process. It is believed that the initial capture of HCV particles by glycosaminoglycans and/or lipoprotein receptors is followed by coordinated interactions with the scavenger receptor class B type I (SR-BI, a major receptor of high-density lipoprotein (HDL, the CD81 tetraspanin, and the tight junction protein Claudin-1, ultimately leading to uptake and cellular penetration of HCV via low-pH endosomes. Several reports have indicated that HDL promotes HCV entry through interaction with SR-BI. This pathway remains largely elusive, although it was shown that HDL neither associates with HCV particles nor modulates HCV binding to SR-BI. In contrast to CD81 and Claudin-1, the importance of SR-BI has only been addressed indirectly because of lack of cells in which functional complementation assays with mutant receptors could be performed. Here we identified for the first time two cell types that supported HCVpp and HCVcc entry upon ectopic SR-BI expression. Remarkably, the undetectable expression of SR-BI in rat hepatoma cells allowed unambiguous investigation of human SR-BI functions during HCV entry. By expressing different SR-BI mutants in either cell line, our results revealed features of SR-BI intracellular domains that influence HCV infectivity without affecting receptor binding and stimulation of HCV entry induced by HDL/SR-BI interaction. Conversely, we identified positions of SR-BI ectodomain that, by altering HCV binding, inhibit entry. Finally, we characterized alternative ectodomain determinants that, by reducing SR-BI cholesterol uptake and efflux functions, abolish HDL-mediated infection-enhancement. Altogether, we demonstrate that SR-BI is an essential HCV entry factor. Moreover, our results highlight specific SR-BI determinants required during HCV entry and physiological lipid transfer functions hijacked by HCV to favor infection.

  5. Dancing on damaged chromatin. Functions of ATM and the RAD50/MRE11/NBS1 complex in cellular responses to DNA damage

    International Nuclear Information System (INIS)

    Iijima, Kenta; Ohara, Maki; Seki, Ryota; Tauchi, Hiroshi

    2008-01-01

    In order to preserve and protect genetic information, eukaryotic cells have developed a signaling or communications network to help the cell respond to DNA damage, and ATM and NBS1 are key players in this network. ATM is a protein kinase which is activated immediately after a DNA double strand break (DSB) is formed, and the resulting signal cascade generated in response to cellular DSBs is regulated by post-translational protein modifications such as phosphorylation and acetylation. In addition, to ensure the efficient functioning of DNA repair and cell cycle checkpoints, the highly ordered structure of eukaryotic chromatin must be appropriately altered to permit access of repair-related factors to DNA. These alterations are termed chromatin remodeling, and are executed by a specific remodeling complex in conjunction with histone modifications. Current advances in the molecular analysis of DNA damage responses have shown that the auto-phosphorylation of ATM and the interaction between ATM and NBS1 are key steps for ATM activation, and that the association of ATM and NBS1 is involved in chromatin remodeling. Identification of novel factors which function in ubiquitination (RNF8, Ubc13, Rap80, etc.) has also enabled us to understand more details of the early stages in DNA repair pathways which respond to DSBs. In this review, the focus is on the role of ATM and the RAD50/MRE11/NBS1 complex in DSB response pathways, and their role in DSB repair and in the regulation of chromatin remodeling. (author)

  6. A mechanical microcompressor for high resolution imaging of motile specimens.

    Science.gov (United States)

    Zinskie, Jessica A; Shribak, Michael; Bruist, Michael F; Aufderheide, Karl J; Janetopoulos, Chris

    2015-10-01

    In order to obtain fine details in 3 dimensions (3D) over time, it is critical for motile biological specimens to be appropriately immobilized. Of the many immobilization options available, the mechanical microcompressor offers many benefits. Our device, previously described, achieves gentle flattening of a cell, allowing us to image finely detailed structures of numerous organelles and physiological processes in living cells. We have imaged protozoa and other small metazoans using differential interference contrast (DIC) microscopy, orientation-independent (OI) DIC, and real-time birefringence imaging using a video-enhanced polychromatic polscope. We also describe an enhancement of our previous design by engineering a new device where the coverslip mount is fashioned onto the top of the base; so the entire apparatus is accessible on top of the stage. The new location allows for easier manipulation of the mount when compressing or releasing a specimen on an inverted microscope. Using this improved design, we imaged immobilized bacteria, yeast, paramecia, and nematode worms and obtained an unprecedented view of cell and specimen details. A variety of microscopic techniques were used to obtain high resolution images of static and dynamic cellular and physiological events. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Effects of radiation upon gastrointestinal motility

    Institute of Scientific and Technical Information of China (English)

    Mary F Otterson

    2007-01-01

    Whether due to therapeutic or belligerent exposure, the gastrointestinal effects of irradiation produce symptoms dreaded by a majority of the population. Nausea, vomiting, diarrhea and abdominal cramping are hallmarks of the prodromal phase of radiation sickness, occurring hours to days following radiation exposure. The prodromal phase is distinct from acute radiation sickness in that the absorptive, secretory and anatomic changes associated with radiation damage are not easily identifiable. It is during this phase of radiation sickness that gastrointestinal motility significantly changes. In addition, there is evidence that motor activity of the gut contributes to some of the acute and chronic effects of radiation.

  8. Merkel Cell Polyomavirus Small T Antigen Drives Cell Motility via Rho-GTPase-Induced Filopodium Formation.

    Science.gov (United States)

    Stakaitytė, Gabrielė; Nwogu, Nnenna; Dobson, Samuel J; Knight, Laura M; Wasson, Christopher W; Salguero, Francisco J; Blackbourn, David J; Blair, G Eric; Mankouri, Jamel; Macdonald, Andrew; Whitehouse, Adrian

    2018-01-15

    upon our previous observations, which demonstrated that the MCPyV ST antigen enhances cell motility, providing a potential link between MCPyV protein expression and the highly metastatic nature of MCC. Here, we show that MCPyV ST remodels the actin cytoskeleton, promoting the formation of filopodia, which is essential for MCPyV ST-induced cell motility, and we also implicate the activity of specific Rho family GTPases, Cdc42 and RhoA, in these processes. Moreover, we describe a novel mechanism for the activation of Rho-GTPases and the cell motility pathway due to the interaction between MCPyV ST and the cellular phosphatase catalytic subunit PP4C, which leads to the specific dephosphorylation of β1 integrin. These findings may therefore provide novel strategies for therapeutic intervention for disseminated MCC. Copyright © 2018 Stakaitytė et al.

  9. Short-Term Pretreatment of Sub-Inhibitory Concentrations of Gentamycin Inhibits the Swarming Motility of Escherichia Coli by Down-Regulating the Succinate Dehydrogenase Gene

    Directory of Open Access Journals (Sweden)

    Yijing Zhuang

    2016-09-01

    Full Text Available Background/Aims: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE on the swarming and swimming motility of Escherichia coli (E. coli remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. Methods: After exposure to sub-inhibitory concentrations (0.8 μg/ml of gentamicin, the swarming and swimming motility of E. coli was tested in semi-solid media. Real-time PCR was used to detect the gene expression of succinate dehydrogenase (SDH. The production of SDH and fumarate by E. coli pretreated with or without gentamycin was measured. Fumarate was added to swarming agar to determine whether fumarate could restore the swarming motility of E. coli. Results: After pretreatment of E. coli with sub-inhibitory concentrations of gentamycin, swarming motility was repressed in the absence of growth inhibition. The expression of all four subunits of SDH was down-regulated, and the intracellular concentration of SDH and fumarate, produced by E. coli, were both decreased. Supplementary fumarate could restore the swarming motility inhibited by gentamycin. A selective inhibitor of SDH (propanedioic acid could strongly repress the swarming motility. Conclusion: Sub-inhibitory concentrations of gentamycin inhibits the swarming motility of E. coli. This effect is mediated by a reduction in cellular fumarate caused by down-regulation of SDH. Gentamycin may be advantageous for treatment of E. coli infections.

  10. Flagellar motility confers epiphytic fitness advantages upon Pseudomonas syringae

    International Nuclear Information System (INIS)

    Haefele, D.M.; Lindow, S.E.

    1987-01-01

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

  11. Carnitine palmitoyltransferase 1A (CPT1A): a transcriptional target of PAX3-FKHR and mediates PAX3-FKHR–dependent motility in alveolar rhabdomyosarcoma cells

    International Nuclear Information System (INIS)

    Liu, Lingling; Wang, Yong-Dong; Wu, Jing; Cui, Jimmy; Chen, Taosheng

    2012-01-01

    Alveolar rhabdomyosarcoma (ARMS) has a high propensity to metastasize, leading to its aggressiveness and a poor survival rate among those with the disease. More than 80% of aggressive ARMSs harbor a PAX3-FKHR fusion transcription factor, which regulates cell migration and promotes metastasis, most likely by regulating the fusion protein’s transcriptional targets. Therefore, identifying druggable transcription targets of PAX3-FKHR that are also downstream effectors of PAX3-FKHR–mediated cell migration and metastasis may lead to novel therapeutic approaches for treating ARMS. To identify genes whose expression is directly affected by the level of PAX3-FKHR in an ARMS cellular-context, we first developed an ARMS cell line in which PAX3-FKHR is stably down-regulated, and showed that stably downregulating PAX3-FKHR in ARMS cells significantly decreased the cells’ motility. We used microarray analysis to identify genes whose expression level decreased when PAX3-FKHR was downregulated. We used mutational analysis, promoter reporter assays, and electrophoretic mobility shift assays to determine whether PAX3-FKHR binds to the promoter region of the target gene. We used siRNA and pharmacologic inhibitor to downregulate the target gene of PAX3-FKHR and investigated the effect of such downregulation on cell motility. We found that when PAX3-FKHR was downregulated, the expression of carnitine palmitoyltransferase 1A (CPT1A) decreased. We showed that PAX3-FKHR binds to a paired-domain binding-site in the CPT1A promoter region, indicating that CPT1A is a novel transcriptional target of PAX3-FKHR. Furthermore, downregulating CPT1A decreased cell motility in ARMS cells, indicating that CPT1A is a downstream effector of PAX3-FKHR–mediated cell migration and metastasis. Taken together, we have identified CPT1A as a novel transcriptional target of PAX3-FKHR and revealed the novel function of CPT1A in promoting cell motility. CPT1A may represent a novel therapeutic target for

  12. Antroduodenal motility in neurologically handicapped children with feeding intolerance

    Directory of Open Access Journals (Sweden)

    Werlin Steven L

    2004-09-01

    Full Text Available Abstract Background Dysphagia and feeding intolerance are common in neurologically handicapped children. The aim is to determine the etiologies of feeding intolerance in neurologically handicapped children who are intolerant of tube feedings. Methods Eighteen neurologically handicapped children, followed in the Tube Feeding Clinic at the Children's Hospital of Wisconsin who were intolerant of gastrostomy feedings. The charts of these 18 patients were reviewed. Past medical history, diagnoses, history of fundoplication and results of various tests of gastrointestinal function including barium contrast radiography, endoscopy and antroduodenal manometry were documented. Results Five of 11 children had abnormal barium upper gastrointestinal series. Seven of 14 had abnormal liquid phase gastric emptying tests. Two of 16 had esophagitis on endoscopy. All 18 children had abnormal antroduodenal motility. Conclusions In neurologically handicapped children foregut dysmotility may be more common than is generally recognized and can explain many of the upper gastrointestinal symptoms in neurologically handicapped children.

  13. LBP based detection of intestinal motility in WCE images

    Science.gov (United States)

    Gallo, Giovanni; Granata, Eliana

    2011-03-01

    In this research study, a system to support medical analysis of intestinal contractions by processing WCE images is presented. Small intestine contractions are among the motility patterns which reveal many gastrointestinal disorders, such as functional dyspepsia, paralytic ileus, irritable bowel syndrome, bacterial overgrowth. The images have been obtained using the Wireless Capsule Endoscopy (WCE) technique, a patented, video colorimaging disposable capsule. Manual annotation of contractions is an elaborating task, since the recording device of the capsule stores about 50,000 images and contractions might represent only the 1% of the whole video. In this paper we propose the use of Local Binary Pattern (LBP) combined with the powerful textons statistics to find the frames of the video related to contractions. We achieve a sensitivity of about 80% and a specificity of about 99%. The achieved high detection accuracy of the proposed system has provided thus an indication that such intelligent schemes could be used as a supplementary diagnostic tool in endoscopy.

  14. Evaluation of methods for assessment of esophageal motility disorders

    Energy Technology Data Exchange (ETDEWEB)

    Endert, G.; Nagel, F.; Erler, M.; Hasse, C.; Ritter, E.P.; Nowak, W. (Medical Academy Erfurt, Clinic of Radiology and Clinic of Surgery (Germany))

    1990-01-01

    The purpose of this study is to compare two forms of parametric imaging of esophageal motility, the condensed image and the esophageal kinetogram, with a standard esophageal transit study in 64 patients with gastro-esophageal reflux disease. The diagnosis was confirmed by endoscopy. A multiple swallow test with a liquid tracer of 150 MBq {sup 99m}Tc-DTPA was used. During the investigation-time of 9 min 300 pictures were recorded and with the KANDI DS-system the parametric images generated and the clearance time, the transit time and the index of reflux were determined. The comparison of kinetogram and condensed image shows a higher sensitivity to detect functional disturbances in the multiple swallow test (kinetogram). In the diagnosis of the reflux disease the transit study and the parametric imaging demonstrated a comparable sensitivity. (orig.).

  15. Evaluation of methods for assessment of esophageal motility disorders

    International Nuclear Information System (INIS)

    Endert, G.; Nagel, F.; Erler, M.; Hasse, C.; Ritter, E.P.; Nowak, W.

    1990-01-01

    The purpose of this study is to compare two forms of parametric imaging of esophageal motility, the condensed image and the esophageal kinetogram, with a standard esophageal transit study in 64 patients with gastro-esophageal reflux disease. The diagnosis was confirmed by endoscopy. A multiple swallow test with a liquid tracer of 150 MBq 99m Tc-DTPA was used. During the investigation-time of 9 min 300 pictures were recorded and with the KANDI DS-system the parametric images generated and the clearance time, the transit time and the index of reflux were determined. The comparison of kinetogram and condensed image shows a higher sensitivity to detect functional disturbances in the multiple swallow test (kinetogram). In the diagnosis of the reflux disease the transit study and the parametric imaging demonstrated a comparable sensitivity. (orig.)

  16. Motility of Pseudomonas aeruginosa contributes to SOS-inducible biofilm formation.

    Science.gov (United States)

    Chellappa, Shakinah T; Maredia, Reshma; Phipps, Kara; Haskins, William E; Weitao, Tao

    2013-12-01

    DNA-damaging antibiotics such as ciprofloxacin induce biofilm formation and the SOS response through autocleavage of SOS-repressor LexA in Pseudomonas aeruginosa. However, the biofilm-SOS connection remains poorly understood. It was investigated with 96-well and lipid biofilm assays. The effects of ciprofloxacin were examined on biofilm stimulation of the SOS mutant and wild-type strains. The stimulation observed in the wild-type in which SOS was induced was reduced in the mutant in which LexA was made non-cleavable (LexAN) and thus SOS non-inducible. Therefore, the stimulation appeared to involve SOS. The possible mechanisms of inducible biofilm formation were explored by subproteomic analysis of outer membrane fractions extracted from biofilms. The data predicted an inhibitory role of LexA in flagellum function. This premise was tested first by functional and morphological analyses of flagellum-based motility. The flagellum swimming motility decreased in the LexAN strain treated with ciprofloxacin. Second, the motility-biofilm assay was performed, which tested cell migration and biofilm formation. The results showed that wild-type biofilm increased significantly over the LexAN. These results suggest that LexA repression of motility, which is the initial event in biofilm development, contributes to repression of SOS-inducible biofilm formation. Copyright © 2013 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. Treating Woman with Myo-Inositol Vaginal Suppositories Improves Partner’s Sperm Motility and Fertility

    Directory of Open Access Journals (Sweden)

    Mario Montanino Oliva

    2016-01-01

    Full Text Available Motility is the feature that allows spermatozoa to actively reach and penetrate the female gamete during fertilization. When this function is altered, and especially decreased, troubles in conceiving may occur. In this study, we demonstrated that treating fertile women with myo-inositol (MI vaginal suppositories ameliorated their partners’ sperm motility and also positively affected their conceiving capacity, without changes in cervical mucus structural and biochemical characteristics. Indeed, by means of the postcoital test on female cervical mucus, a significant improvement especially in progressive sperm motility was recorded after MI suppository use. Concomitantly, after MI treatment, a reduction of immotile spermatozoa percentage was observed. Importantly, MI vaginal supplementation positively correlated with a pregnancy for 5 of the 50 couples enrolled in the study, leading us to speculate that this substance may substantially contribute to create in the cervical mucus an ideal milieu that makes spermatozoa more motile and functionally able to fertilize. Even though the detailed mechanism is still unclear, these results should encourage MI vaginal use for the clinical improvement of male infertility, through their partners.

  18. HPN-07, a free radical spin trapping agent, protects against functional, cellular and electrophysiological changes in the cochlea induced by acute acoustic trauma

    Science.gov (United States)

    Hu, Ning; Du, Xiaoping; Li, Wei; West, Matthew B.; Choi, Chul-Hee; Floyd, Robert; Kopke, Richard D.

    2017-01-01

    Oxidative stress is considered a major cause of the structural and functional changes associated with auditory pathologies induced by exposure to acute acoustic trauma AAT). In the present study, we examined the otoprotective effects of 2,4-disulfophenyl-N-tert-butylnitrone (HPN-07), a nitrone-based free radical trap, on the physiological and cellular changes in the auditory system of chinchilla following a six-hour exposure to 4 kHz octave band noise at 105 dB SPL. HPN-07 has been shown to suppress oxidative stress in biological models of a variety of disorders. Our results show that administration of HPN-07 beginning four hours after acoustic trauma accelerated and enhanced auditory/cochlear functional recovery, as measured by auditory brainstem responses (ABR), distortion product otoacoustic emissions (DPOAE), compound action potentials (CAP), and cochlear microphonics (CM). The normally tight correlation between the endocochlear potential (EP) and evoked potentials of CAP and CM were persistently disrupted after noise trauma in untreated animals but returned to homeostatic conditions in HPN-07 treated animals. Histological analyses revealed several therapeutic advantages associated with HPN-07 treatment following AAT, including reductions in inner and outer hair cell loss; reductions in AAT-induced loss of calretinin-positive afferent nerve fibers in the spiral lamina; and reductions in fibrocyte loss within the spiral ligament. These findings support the conclusion that early intervention with HPN-07 following an AAT efficiently blocks the propagative ototoxic effects of oxidative stress, thereby preserving the homeostatic and functional integrity of the cochlea. PMID:28832600

  19. System-level insights into the cellular interactome of a non-model organism: inferring, modelling and analysing functional gene network of soybean (Glycine max.

    Directory of Open Access Journals (Sweden)

    Yungang Xu

    Full Text Available Cellular interactome, in which genes and/or their products interact on several levels, forming transcriptional regulatory-, protein interaction-, metabolic-, signal transduction networks, etc., has attracted decades of research focuses. However, such a specific type of network alone can hardly explain the various interactive activities among genes. These networks characterize different interaction relationships, implying their unique intrinsic properties and defects, and covering different slices of biological information. Functional gene network (FGN, a consolidated interaction network that models fuzzy and more generalized notion of gene-gene relations, have been proposed to combine heterogeneous networks with the goal of identifying functional modules supported by multiple interaction types. There are yet no successful precedents of FGNs on sparsely studied non-model organisms, such as soybean (Glycine max, due to the absence of sufficient heterogeneous interaction data. We present an alternative solution for inferring the FGNs of soybean (SoyFGNs, in a pioneering study on the soybean interactome, which is also applicable to other organisms. SoyFGNs exhibit the typical characteristics of biological networks: scale-free, small-world architecture and modularization. Verified by co-expression and KEGG pathways, SoyFGNs are more extensive and accurate than an orthology network derived from Arabidopsis. As a case study, network-guided disease-resistance gene discovery indicates that SoyFGNs can provide system-level studies on gene functions and interactions. This work suggests that inferring and modelling the interactome of a non-model plant are feasible. It will speed up the discovery and definition of the functions and interactions of other genes that control important functions, such as nitrogen fixation and protein or lipid synthesis. The efforts of the study are the basis of our further comprehensive studies on the soybean functional

  20. The role of focal adhesion kinase in the regulation of cellular mechanical properties

    International Nuclear Information System (INIS)

    Mierke, Claudia Tanja

    2013-01-01

    The regulation of mechanical properties is necessary for cell invasion into connective tissue or intra- and extravasation through the endothelium of blood or lymph vessels. Cell invasion is important for the regulation of many healthy processes such as immune response reactions and wound healing. In addition, cell invasion plays a role in disease-related processes such as tumor metastasis and autoimmune responses. Until now the role of focal adhesion kinase (FAK) in regulating mechanical properties of cells and its impact on cell invasion efficiency is still not well known. Thus, this review focuses on mechanical properties regulated by FAK in comparison to the mechano-regulating protein vinculin. Moreover, it points out the connection between cancer cell invasion and metastasis and FAK by showing that FAK regulates cellular mechanical properties required for cellular motility. Furthermore, it sheds light on the indirect interaction of FAK with vinculin by binding to paxillin, which then impairs the binding of paxillin to vinculin. In addition, this review emphasizes whether FAK fulfills regulatory functions similar to vinculin. In particular, it discusses the differences and the similarities between FAK and vinculin in regulating the biomechanical properties of cells. Finally, this paper highlights that both focal adhesion proteins, vinculin and FAK, synergize their functions to regulate the mechanical properties of cells such as stiffness and contractile forces. Subsequently, these mechanical properties determine cellular invasiveness into tissues and provide a source sink for future drug developments to inhibit excessive cell invasion and hence, metastases formation. (paper)

  1. The role of focal adhesion kinase in the regulation of cellular mechanical properties

    Science.gov (United States)

    Mierke, Claudia Tanja

    2013-12-01

    The regulation of mechanical properties is necessary for cell invasion into connective tissue or intra- and extravasation through the endothelium of blood or lymph vessels. Cell invasion is important for the regulation of many healthy processes such as immune response reactions and wound healing. In addition, cell invasion plays a role in disease-related processes such as tumor metastasis and autoimmune responses. Until now the role of focal adhesion kinase (FAK) in regulating mechanical properties of cells and its impact on cell invasion efficiency is still not well known. Thus, this review focuses on mechanical properties regulated by FAK in comparison to the mechano-regulating protein vinculin. Moreover, it points out the connection between cancer cell invasion and metastasis and FAK by showing that FAK regulates cellular mechanical properties required for cellular motility. Furthermore, it sheds light on the indirect interaction of FAK with vinculin by binding to paxillin, which then impairs the binding of paxillin to vinculin. In addition, this review emphasizes whether FAK fulfills regulatory functions similar to vinculin. In particular, it discusses the differences and the similarities between FAK and vinculin in regulating the biomechanical properties of cells. Finally, this paper highlights that both focal adhesion proteins, vinculin and FAK, synergize their functions to regulate the mechanical properties of cells such as stiffness and contractile forces. Subsequently, these mechanical properties determine cellular invasiveness into tissues and provide a source sink for future drug developments to inhibit excessive cell invasion and hence, metastases formation.

  2. The preventive effect of vitamin C on the cellular and functional integrity of kidney cells in rats following repeated exposure to paraquat

    Directory of Open Access Journals (Sweden)

    Benjamin Nnamdi Okolonkwo

    2014-11-01

    Full Text Available Paraquat (PQ is a bipyridylium herbicide that is applied around trees in orchards and between crop rows to control broad-leaved and grassy weeds. Its oxidation results in the formation of superoxides which causes damage to cellular components. In this study, we determined the antioxidant effect vitamin C has on the cellular integrity of kidney function in rats following repeated exposure to PQ. Ninety-six male rats, grouped twelve rats per subgroup (A, Avit.c, B, Bvit.c, C, Cvit.c, D and Dvit.c were intraperitoneally injected with different sublethal increasing doses (0, 0, 2, 2, 4, 4, 6 and 6 mg/kg body weight of PQ respectively on biweekly (14 days intervals over a period of three months (84 days. Subsequently, the subgrouped animals (Avit.c, Bvit.c, Cvit.c and Dvit.c were maintained orally with 1 g/L vitamin C, while the other subgrouped animals (A, B, C and D received drinking water with negligible vitamin content throughout the study period. At the end of each monthly (28 days treatment, four animals per subgroup were selected. Urine samples were collected from each of the selected rats, after which each of the animals were anaesthetized with gaseous isoflurane and 5 mL of blood samples were collected using cardiac puncture procedure. The animals were later decapitated and their kidneys harvested. The samples collected were analyzed for urine [specific gravity (SG, pH, protein and glucose], blood (urea, creatinine, total protein and glucose, and the histological studies on kidney slides. The dose and exposure- time dependent PQ toxicity resulted in the reduction in urinary pH, elevation in urinary SG, and the detectable presence of protein and glucose in urine. It also caused marked elevation in serum urea and creatinine levels with reduction in serum protein and glucose levels and alterations in the cellular integrity of the renal architecture, especially the glomeruli and tubular tissues. Treatments on the PQ insulted animals with vitamin

  3. Lysine-functionalized nanodiamonds as gene carriers: development of stable colloidal dispersion for in vitro cellular uptake studies and siRNA delivery application

    Directory of Open Access Journals (Sweden)

    Alwani S

    2016-02-01

    Full Text Available Saniya Alwani,1 Randeep Kaur,1 Deborah Michel,1 Jackson M Chitanda,2 Ronald E Verrall,3 Chithra Karunakaran,4 Ildiko Badea1 1Drug Design and Discovery Research Group, College of Pharmacy and Nutrition, 2Department of Chemical & Biological Engineering, 3Department of Chemistry, University of Saskatchewan, 4Canadian Light Source, Saskatoon, SK, Canada Purpose: Nanodiamonds (NDs are emerging as an attractive tool for gene therapeutics. To reach their full potential for biological application, NDs should maintain their colloidal stability in biological milieu. This study describes the behavior of lysine-functionalized ND (lys-ND in various dispersion media, with an aim to limit aggregation and improve the colloidal stability of ND-gene complexes called diamoplexes. Furthermore, cellular and macromolecular interactions of lys-NDs are also analyzed in vitro to establish the understanding of ND-mediated gene transfer in cells. Methods: lys-NDs were synthesized earlier through covalent conjugation of lysine amino acid to carboxylated NDs surface generated through re-oxidation in strong oxidizing acids. In this study, dispersions of lys-NDs were prepared in various media, and the degree of sedimentation was monitored for 72 hours. Particle size distributions and zeta potential measurements were performed for a period of 25 days to characterize the physicochemical stability of lys-NDs in the medium. The interaction profile of lys-NDs with fetal bovine serum showed formation of a protein corona, which was evaluated by size and charge distribution measurements. Uptake of lys-NDs in cervical cancer cells was analyzed by scanning transmission X-ray microscopy, flow cytometry, and confocal microscopy. Cellular uptake of diamoplexes (complex of lys-NDs with small interfering RNA was also analyzed using flow cytometry. Results: Aqueous dispersion of lys-NDs showed minimum sedimentation and remained stable over a period of 25 days. Size distributions showed

  4. Coupling of cytoskeleton functions for fibroblast locomotion

    DEFF Research Database (Denmark)

    Couchman, J R; Lenn, M; Rees, D A

    1985-01-01

    caused visible protrusions in projected positions at the leading edge. We conclude that fibroblast locomotion may be driven coordinately by a common set of motility mechanisms and that this coordination may be lost as a result of physical or pharmacological disturbance. Taking our evidence with results...... from other Laboratories, we propose the following cytoskeleton functions. (i) Protrusive activity, probably based on solation--gelation cycles of the actin based cytoskeleton and membrane recycling which provides cellular and membrane components for streaming through the cell body to the leading edge...

  5. Morphed and moving: TNFα-driven motility promotes cell dissemination through MAP4K4-induced cytoskeleton remodeling

    Directory of Open Access Journals (Sweden)

    Min Ma

    2014-04-01

    Full Text Available Cell dissemination from an initial site of growth is a highly coordinated and controlled process that depends on cell motility. The mechanistic principles that orchestrate cell motility, namely cell shape control, traction and force generation, are highly conserved between cells of different origins. Correspondingly, the molecular mechanisms that regulate these critical aspects of migrating cells are likely functionally conserved too. Thus, cell motility deregulation of unrelated pathogenesis could be caused and maintained by similar mechanistic principles. One such motility deregulation disorder is the leukoproliferative cattle disease Tropical Theileriosis, which is caused by the intracellular, protozoan parasite Theileria annulata. T. annulata transforms its host cell and promotes the dissemination of parasite-infected cells throughout the body of the host. An analogous condition with a fundamentally different pathogenesis is metastatic cancer, where oncogenically transformed cells disseminate from the primary tumor to form distant metastases. Common to both diseases is the dissemination of motile cells from the original site. However, unlike metastatic cancer, host cell transformation by Theileria parasites can be reverted by drug treatment and cell signaling be analyzed under transformed and non-transformed conditions. We have used this reversible transformation model and investigated parasite control of host cell motile properties in the context of inflammatory signaling in Ma M. et al. [PLoS Pathog (2014 10: e1004003]. We found that parasite infection promotes the production of the inflammatory cytokine TNFα in the host macrophage. We demonstrated that increased TNFα triggers motile and invasive properties by enhancing actin cytoskeleton remodeling and cell motility through the ser/thr kinase MAP4K4. We concluded that inflammatory conditions resulting in increased TNFα could facilitate cell dissemination by activating the actin

  6. Molecular and Cellular Signaling

    CERN Document Server

    Beckerman, Martin

    2005-01-01

    A small number of signaling pathways, no more than a dozen or so, form a control layer that is responsible for all signaling in and between cells of the human body. The signaling proteins belonging to the control layer determine what kinds of cells are made during development and how they function during adult life. Malfunctions in the proteins belonging to the control layer are responsible for a host of human diseases ranging from neurological disorders to cancers. Most drugs target components in the control layer, and difficulties in drug design are intimately related to the architecture of the control layer. Molecular and Cellular Signaling provides an introduction to molecular and cellular signaling in biological systems with an emphasis on the underlying physical principles. The text is aimed at upper-level undergraduates, graduate students and individuals in medicine and pharmacology interested in broadening their understanding of how cells regulate and coordinate their core activities and how diseases ...

  7. D77, one benzoic acid derivative, functions as a novel anti-HIV-1 inhibitor targeting the interaction between integrase and cellular LEDGF/p75

    International Nuclear Information System (INIS)

    Du Li; Zhao Yaxue; Chen, Jing; Yang Liumeng; Zheng Yongtang; Tang Yun; Shen Xu; Jiang Hualiang

    2008-01-01

    Integration of viral-DNA into host chromosome mediated by the viral protein HIV-1 integrase (IN) is an essential step in the HIV-1 life cycle. In this process, Lens epithelium-derived growth factor (LEDGF/p75) is discovered to function as a cellular co-factor for integration. Since LEDGF/p75 plays an important role in HIV integration, disruption of the LEDGF/p75 interaction with IN has provided a special interest for anti-HIV agent discovery. In this work, we reported that a benzoic acid derivative, 4-[(5-bromo-4-{[2,4-dioxo-3-(2-oxo-2-phenylethyl) -1,3-thiazolidin-5-ylidene]methyl}-2-ethoxyphenoxy)methyl]benzoic acid (D77) could potently inhibit the IN-LEDGF/p75 interaction and affect the HIV-1 IN nuclear distribution thus exhibiting antiretroviral activity. Molecular docking with site-directed mutagenesis analysis and surface plasmon resonance (SPR) binding assays has clarified possible binding mode of D77 against HIV-1 integrase. As the firstly discovered small molecular compound targeting HIV-1 integrase interaction with LEDGF/p75, D77 might supply useful structural information for further anti-HIV agent discovery

  8. The role of the Frank-Starling law in the transduction of cellular work to whole organ pump function: a computational modeling analysis.

    Directory of Open Access Journals (Sweden)

    Steven A Niederer

    2009-04-01

    Full Text Available We have developed a multi-scale biophysical electromechanics model of the rat left ventricle at room temperature. This model has been applied to investigate the relative roles of cellular scale length dependent regulators of tension generation on the transduction of work from the cell to whole organ pump function. Specifically, the role of the length dependent Ca(2+ sensitivity of tension (Ca(50, filament overlap tension dependence, velocity dependence of tension, and tension dependent binding of Ca(2+ to Troponin C on metrics of efficient transduction of work and stress and strain homogeneity were predicted by performing simulations in the absence of each of these feedback mechanisms. The length dependent Ca(50 and the filament overlap, which make up the Frank-Starling Law, were found to be the two dominant regulators of the efficient transduction of work. Analyzing the fiber velocity field in the absence of the Frank-Starling mechanisms showed that the decreased efficiency in the transduction of work in the absence of filament overlap effects was caused by increased post systolic shortening, whereas the decreased efficiency in the absence of length dependent Ca(50 was caused by an inversion in the regional distribution of strain.

  9. Epitope-based vaccines with the Anaplasma marginale MSP1a functional motif induce a balanced humoral and cellular immune response in mice.

    Directory of Open Access Journals (Sweden)

    Paula S Santos

    Full Text Available Bovine anaplasmosis is a hemoparasitic disease that causes considerable economic loss to the dairy and beef industries. Cattle immunized with the Anaplasma marginale MSP1 outer membrane protein complex presents a protective humoral immune response; however, its efficacy is variable. Immunodominant epitopes seem to be a key-limiting factor for the adaptive immunity. We have successfully demonstrated that critical motifs of the MSP1a functional epitope are essential for antibody recognition of infected animal sera, but its protective immunity is yet to be tested. We have evaluated two synthetic vaccine formulations against A. marginale, using epitope-based approach in mice. Mice infection with bovine anaplasmosis was demonstrated by qPCR analysis of erythrocytes after 15-day exposure. A proof-of-concept was obtained in this murine model, in which peptides conjugated to bovine serum albumin were used for immunization in three 15-day intervals by intraperitoneal injections before challenging with live bacteria. Blood samples were analyzed for the presence of specific IgG2a and IgG1 antibodies, as well as for the rickettsemia analysis. A panel containing the cytokines' transcriptional profile for innate and adaptive immune responses was carried out through qPCR. Immunized BALB/c mice challenged with A. marginale presented stable body weight, reduced number of infected erythrocytes, and no mortality; and among control groups mortality rates ranged from 15% to 29%. Additionally, vaccines have significantly induced higher IgG2a than IgG1 response, followed by increased expression of pro-inflammatory cytokines. This is a successful demonstration of epitope-based vaccines, and protection against anaplasmosis may be associated with elicitation of effector functions of humoral and cellular immune responses in murine model.

  10. Functional cross-talk between the cellular prion protein and the neural cell adhesion molecule is critical for neuronal differentiation of neural stem/precursor cells.

    Science.gov (United States)

    Prodromidou, Kanella; Papastefanaki, Florentia; Sklaviadis, Theodoros; Matsas, Rebecca

    2014-06-01

    Cellular prion protein (PrP) is prominently expressed in brain, in differentiated neurons but also in neural stem/precursor cells (NPCs). The misfolding of PrP is a central event in prion diseases, yet the physiological function of PrP is insufficiently understood. Although PrP has been reported to associate with the neural cell adhesion molecule (NCAM), the consequences of concerted PrP-NCAM action in NPC physiology are unknown. Here, we generated NPCs from the subventricular zone (SVZ) of postnatal day 5 wild-type and PrP null (-/-) mice and observed that PrP is essential for proper NPC proliferation and neuronal differentiation. Moreover, we found that PrP is required for the NPC response to NCAM-induced neuronal differentiation. In the absence of PrP, NCAM not only fails to promote neuronal differentiation but also induces an accumulation of doublecortin-positive neuronal progenitors at the proliferation stage. In agreement, we noted an increase in cycling neuronal progenitors in the SVZ of PrP-/- mice compared with PrP+/+ mice, as evidenced by double labeling for the proliferation marker Ki67 and doublecortin as well as by 5-bromo-2'-deoxyuridine incorporation experiments. Additionally, fewer newly born neurons were detected in the rostral migratory stream of PrP-/- mice. Analysis of the migration of SVZ cells in microexplant cultures from wild-type and PrP-/- mice revealed no differences between genotypes or a role for NCAM in this process. Our data demonstrate that PrP plays a critical role in neuronal differentiation of NPCs and suggest that this function is, at least in part, NCAM-dependent. © 2014 AlphaMed Press.

  11. The species origin of the cellular microenvironment influences markers of beta cell fate and function in EndoC-βH1 cells.

    Science.gov (United States)

    Jeffery, N; Richardson, S; Beall, C; Harries, L W

    2017-12-15

    Interaction between islet cell subtypes and the extracellular matrix influences beta-cell function in mammals. The tissue architecture of rodent islets is very different to that of human islets; cell-to-cell communication and interaction with the extracellular matrix may vary between species. In this work, we have compared the responses of the human EndoC-βH1 cell line to non-human and human-derived growth matrices in terms of growth morphology, gene expression and glucose-stimulated insulin secretion (GSIS). EndoC-βH1 cells demonstrated a greater tendency to form cell clusters when cultured in a human microenvironment and exhibited reduced alpha cell markers at the mRNA level; mean expression difference - 0.23 and - 0.51; p = 0.009 and 0.002 for the Aristaless-related homeobox (ARX) and Glucagon (GCG) genes respectively. No differences were noted in the protein expression of mature beta cell markers such as Pdx1 and NeuroD1 were noted in EndoC-βH1 cells grown in a human microenvironment but cells were however more sensitive to glucose (4.3-fold increase in insulin secretion following glucose challenge compared with a 1.9-fold increase in cells grown in a non-human microenvironment; p = 0.0003). Our data suggests that the tissue origin of the cellular microenvironment has effects on the function of EndoC-βH1 cells in vitro, and the use of a more human-like culture microenvironment may bring benefits in terms of increased physiological relevance. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Comparative genomic analysis of buffalo (Bubalus bubalis NOD1 and NOD2 receptors and their functional role in in-vitro cellular immune response.

    Directory of Open Access Journals (Sweden)

    Biswajit Brahma

    Full Text Available Nucleotide binding and oligomerization domain (NOD-like receptors (NLRs are innate immune receptors that recognize bacterial cell wall components and initiate host immune response. Structure and function of NLRs have been well studied in human and mice, but little information exists on genetic composition and role of these receptors in innate immune system of water buffalo--a species known for its exceptional disease resistance. Here, a comparative study on the functional domains of NOD1 and NOD2 was performed across different species. The NOD mediated in-vitro cellular responses were studied in buffalo peripheral blood mononuclear cells, resident macrophages, mammary epithelial, and fibroblast cells. Buffalo NOD1 (buNOD1 and buNOD2 showed conserved domain architectures as found in other mammals. The domains of buNOD1 and buNOD2 showed analogy in secondary and tertiary conformations. Constitutive expressions of NODs were ubiquitous in different tissues. Following treatment with NOD agonists, peripheral lymphocytes showed an IFN-γ response along-with production of pro-inflammatory cytokines. Alveolar macrophages and mammary epithelial cells showed NOD mediated in-vitro immune response through NF-κB dependent pathway. Fibroblasts showed pro-inflammatory cytokine response following agonist treatment. Our study demonstrates that both immune and non-immune cells could generate NOD-mediated responses to pathogens though the type and magnitude of response depend on the cell types. The structural basis of ligand recognition by buffalo NODs and knowledge of immune response by different cell types could be useful for development of non-infective innate immune modulators and next generation anti-inflammatory compounds.

  13. Autocrine motility factor (neuroleukin, phosphohexose isomerase) induces cell movement through 12-lipoxygenase-dependent tyrosine phosphorylation and serine dephosphorylation events.

    Science.gov (United States)

    Timár, J; Tóth, S; Tóvári, J; Paku, S; Raz, A

    1999-01-01

    Autocrine motility factor (AMF) is one of the motility cytokines regulating tumor cell migration, therefore identification of the signaling pathway coupled with it has critical importance. Previous studies revealed several elements of this pathway predominated by lipoxygenase-PKC activations but the role for tyrosine kinases remained questionable. Motility cytokines frequently have mitogenic effect as well, producing activation of overlapping signaling pathways therefore we have used B16a melanoma cells as models where AMF has exclusive motility effect. Our studies revealed that in B16a cells AMF initiated rapid (1-5 min) activation of the protein tyrosine kinase (PTK) cascade inducing phosphorylation of 179, 125, 95 and 40/37 kD proteins which was mediated by upstream cyclo- and lipoxygenases. The phosphorylated proteins were localized to the cortical actin-stress fiber attachment zones in situ by confocal microscopy. On the other hand, AMF receptor activation induced significant decrease in overall serine-phosphorylation level of cellular proteins accompanied by serine phosphorylation of 200, 90, 78 and 65 kd proteins. The decrease in serine phosphorylation was independent of PTKs, PKC as well as cyclo- and lipoxygenases. However, AMF induced robust translocation of PKCalpha to the stress fibers and cortical actin suggesting a critical role for this kinase in the generation of the motility signal. Based on the significant decrease in serine phosphorylation after AMF stimulus in B16a cells we postulated the involvement of putative serine/threonine phosphatase(s) upstream lipoxygenase and activation of the protein tyrosine kinase cascade downstream cyclo- and lipoxygenase(s) in the previously identified autocrine motility signal.

  14. Gold nanoparticles cellular toxicity and recovery: adipose Derived Stromal cells.

    Science.gov (United States)

    Mironava, Tatsiana; Hadjiargyrou, Michael; Simon, Marcia; Rafailovich, Miriam H

    2014-03-01

    Gold nanoparticles (AuNPs) are currently used in numerous medical applications. Herein, we describe their in vitro impact on human adipose-derived stromal cells (ADSCs) using 13 nm and 45 nm citrate-coated AuNPs. In their non-differentiated state, ADSCs were penetrated by the AuNPs and stored in vacuoles. The presence of the AuNPs in ADSCs resulted in increased population doubling times, decreased cell motility and cell-mediated collagen contraction. The degree to which the cells were impacted was a function of particle concentration, where the smaller particles required a sevenfold higher concentration to have the same effect as the larger ones. Furthermore, AuNPs reduced adipogenesis as measured by lipid droplet accumulation and adiponectin secretion. These effects correlated with transient increases in DLK1 and with relative reductions in fibronectin. Upon removal of exogenous AuNPs, cellular NP levels decreased and normal ADSC functions were restored. As adiponectin helps regulate energy metabolism, local fluctuations triggered by AuNPs can lead to systemic changes. Hence, careful choice of size, concentration and clinical application duration of AuNPs is warranted.

  15. Acotiamide hydrochloride (Z-338) enhances gastric motility and emptying by inhibiting acetylcholinesterase activity in rats.

    Science.gov (United States)

    Kawachi, Masanao; Matsunaga, Yugo; Tanaka, Takao; Hori, Yuko; Ito, Katsunori; Nagahama, Kenji; Ozaki, Tomoko; Inoue, Naonori; Toda, Ryoko; Yoshii, Kazuyoshi; Hirayama, Masamichi; Kawabata, Yoshihiro; Takei, Mineo

    2011-09-01

    In clinical trials, acotiamide hydrochloride (acotiamide: Z-338) has been reported to be useful in the treatment of functional dyspepsia. Here, we investigated the effects of acotiamide on gastric contraction and emptying activities in rats in comparison with itopride hydrochloride (itopride) and mosapride citrate (mosapride). We also examined in vitro the compound's inhibitory effect on acetylcholinesterase (AChE) activity derived from rat stomach. In in vivo studies, acotiamide (30 and 100mg/kg s.c.) and itopride (100mg/kg s.c.) markedly enhanced normal gastric antral motility in rats. In gastric motility dysfunction models, acotiamide (100mg/kg s.c.) and itopride (100mg/kg s.c.) improved both gastric antral hypomotility and the delayed gastric emptying induced by clonidine, an α(2)-adrenoceptor agonist. In contrast, mosapride (10mg/kg s.c.) had no effect on these models. Like the AChE inhibitors itopride (30 mg/kg s.c.) and neostigmine (10 μg/kg s.c.), acotiamide (10mg/kg s.c.) also clearly enhanced gastric body contractions induced by electrical stimulation of the vagus, which were abolished by atropine and hexamethonium, whereas mosapride (3 and 10mg/kg s.c.) did not. In in vitro studies, acotiamide concentration-dependently inhibited rat stomach-derived AChE activity (IC(50)=2.3 μmol/l). In addition, stomach tissue concentrations of acotiamide after administration at 10mg/kg s.c. were sufficient to produce inhibition of AChE activity in rat stomach. These results suggest that acotiamide stimulates gastric motility and improves gastric motility dysfunction in rats by inhibiting AChE activity, and may suggest a role for acotiamide in improving gastric motility dysfunction in patients with functional dyspepsia. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Identification of an operon, Pil-Chp, that controls twitching motility and virulence in Xylella fastidiosa.

    Science.gov (United States)

    Cursino, Luciana; Galvani, Cheryl D; Athinuwat, Dusit; Zaini, Paulo A; Li, Yaxin; De La Fuente, Leonardo; Hoch, Harvey C; Burr, Thomas J; Mowery, Patricia

    2011-10-01

    Xylella fastidiosa is an important phytopathogenic bacterium that causes many serious plant diseases, including Pierce's disease of grapevines. Disease manifestation by X. fastidiosa is associated with the expression of several factors, including the type IV pili that are required for twitching motility. We provide evidence that an operon, named Pil-Chp, with genes homologous to those found in chemotaxis systems, regulates twitching motility. Transposon insertion into the pilL gene of the operon resulted in loss of twitching motility (pilL is homologous to cheA genes encoding kinases). The X. fastidiosa mutant maintained the type IV pili, indicating that the disrupted pilL or downstream operon genes are involved in pili function, and not biogenesis. The mutated X. fastidiosa produced less biofilm than wild-type cells, indicating that the operon contributes to biofilm formation. Finally, in planta the mutant produced delayed and less severe disease, indicating that the Pil-Chp operon contributes to the virulence of X. fastidiosa, presumably through its role in twitching motility.

  17. Software-assisted small bowel motility analysis using free-breathing MRI: feasibility study.

    Science.gov (United States)

    Bickelhaupt, Sebastian; Froehlich, Johannes M; Cattin, Roger; Raible, Stephan; Bouquet, Hanspeter; Bill, Urs; Patak, Michael A

    2014-01-01

    To validate a software prototype allowing for small bowel motility analysis in free breathing by comparing it to manual measurements. In all, 25 patients (15 male, 10 female; mean age 39 years) were included in this Institutional Review Board-approved, retrospective study. Magnetic resonance imaging (MRI) was performed on a 1.5T system after standardized preparation acquiring motility sequences in free breathing over 69-84 seconds. Small bowel motility was analyzed manually and with the software. Functional parameters, measurement time, and reproducibility were compared using the coefficient of variance and paired Student's t-test. Correlation was analyzed using Pearson's correlation coefficient and linear regression. The 25 segments were analyzed twice both by hand and using the software with automatic breathing correction. All assessed parameters significantly correlated between the methods (P software (3.90%, standard deviation [SD] ± 5.69) than manual examinations (9.77%, SD ± 11.08). The time needed was significantly less (P software (4.52 minutes, SD ± 1.58) compared to manual measurement, lasting 17.48 minutes for manual (SD ± 1.75 minutes). The use of the software proves reliable and faster small bowel motility measurements in free-breathing MRI compared to manual analyses. The new technique allows for analyses of prolonged sequences acquired in free breathing, improving the informative value of the examinations by amplifying the evaluable data. Copyright © 2013 Wiley Periodicals, Inc.

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

    DEFF Research Database (Denmark)

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

    2005-01-01

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

  19. The management of motility disorders in critical illness | Retief ...

    African Journals Online (AJOL)

    Gastric motility disorders in the intensive care unit (ICU) are a reality leading to many complications including inadequate EN delivery. Care should be taken to understand what type of gastric motility disorder is present and therapy should be prescribed early to prevent worsening of clinical outcomes.

  20. Detection and genomic characterization of motility in Lactobacillus curvatus: confirmation of motility in a species outside the Lactobacillus salivarius clade.

    Science.gov (United States)

    Cousin, Fabien J; Lynch, Shónagh M; Harris, Hugh M B; McCann, Angela; Lynch, Denise B; Neville, B Anne; Irisawa, Tomohiro; Okada, Sanae; Endo, Akihito; O'Toole, Paul W

    2015-02-01

    Lactobacillus is the largest genus within the lactic acid bacteria (LAB), with almost 180 species currently identified. Motility has been reported for at least 13 Lactobacillus species, all belonging to the Lactobacillus salivarius clade. Motility in lactobacilli is poorly characterized. It probably confers competitive advantages, such as superior nutrient acquisition and niche colonization, but it could also play an important role in innate immune system activation through flagellin–Toll-like receptor 5 (TLR5) interaction. We now report strong evidence of motility in a species outside the L. salivarius clade, Lactobacillus curvatus (strain NRIC0822). The motility of L. curvatus NRIC 0822 was revealed by phase-contrast microscopy and soft-agar motility assays. Strain NRIC 0822 was motile at temperatures between 15 °C and 37 °C, with a range of different carbohydrates, and under varying atmospheric conditions. We sequenced the L. curvatus NRIC 0822 genome, which revealed that the motility genes are organized in a single operon and that the products are very similar (>98.5% amino acid similarity over >11,000 amino acids) to those encoded by the motility operon of Lactobacillus acidipiscis KCTC 13900 (shown for the first time to be motile also). Moreover, the presence of a large number of mobile genetic elements within and flanking the motility operon of L. curvatus suggests recent horizontal transfer between members of two distinct Lactobacillus clades: L. acidipiscis in the L. salivarius clade and L. curvatus inthe L. sakei clade. This study provides novel phenotypic, genetic, and phylogenetic insights into flagellum-mediated motility in lactobacilli.

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  2. Mechanics model for actin-based motility.

    Science.gov (United States)

    Lin, Yuan

    2009-02-01

    We present here a mechanics model for the force generation by actin polymerization. The possible adhesions between the actin filaments and the load surface, as well as the nucleation and capping of filament tips, are included in this model on top of the well-known elastic Brownian ratchet formulation. A closed form solution is provided from which the force-velocity relationship, summarizing the mechanics of polymerization, can be drawn. Model predictions on the velocity of moving beads driven by actin polymerization are consistent with experiment observations. This model also seems capable of explaining the enhanced actin-based motility of Listeria monocytogenes and beads by the presence of Vasodilator-stimulated phosphoprotein, as observed in recent experiments.

  3. Thyroxin Is Useful to Improve Sperm Motility

    Directory of Open Access Journals (Sweden)

    Mendeluk Gabriela Ruth

    2016-07-01

    Full Text Available Background The aim of this study was to evaluate the non-genomic action of thyroxin on sperm kinetic and its probable use to improve sperm recovery after applying an en- richment method like “swim-up” in comparison with the available one, pentoxifylline. Materials and Methods This is an experimental study. A total of 50 patients were re- cruited, followed by infertility consultation. Conventional sperm assays were performed according to World Health Organization criteria-2010 (WHO-2010. A Computer Aided Semen Analysis System was employed to assess kinetic parameters and concentrations. Number of the motile sperm recovered after preparation technique was calculated. Results Addition of T4 (0.002 µg/ml to semen samples increased hypermotility at 20 minutes (control: 14.18 ± 5.1% vs. 17.66 ± 8.88%, P<0.03, data expressed as mean ± SD and remained unchanged after 40 minutes. Significant differences were found in the motile sperm recovered after swim-up (control: 8.93×106 ± 9.52× 06vs. 17.20×106 ± 21.16×106, P<0.03, achieving all of the tested samples a desirable threshold value for artificial insemination outcome, while adding pentoxifylline increased the number of recovered sperm after swim-up in 60% of the studied cases. No synergism between two treatments could be determined. Conclusion We propose a new physiological tool to artificially improve insemination. The discussion opens windows to investigate unknown pathways involved in sperm ca- pacitation and gives innovative arguments to better understand infertility mechanisms.

  4. Motility of copepod nauplii and implications for food encounter

    DEFF Research Database (Denmark)

    Titelman, Josefin; Kiørboe, Thomas

    2003-01-01

    (Centropages typicus, Calanus helgolandicus, Temora longicornis, Acartia tonsa, Eurytemora affinis and Euterpina acutifrons). Behaviors of individual nauphi were divided into sequences of sinking, swimming and jumping events. Motility behavior is both stage- and species-specific in terms of appearance......Velocity differences drive all encounter processes. Therefore, knowledge of both prey and predator motility are essential in order to understand feeding behavior and predict food acquisition rates. Here, we describe and quantify the motility behavior of young and old naupliar stages of 6 copepods...... of tracks, speeds, durations and frequencies of events as well as time budgets. Motility mode often changes drastically during naupliar ontogeny. Crudely, nauplii can be divided into those moving with a jump-sink type of motility of various frequencies (1 min(-1) to 3 s(-1)) and those swimming...

  5. Intracellular Transport and Kinesin Superfamily Proteins: Structure, Function and Dynamics

    Science.gov (United States)

    Hirokawa, N.; Takemura, R.

    Using various molecular cell biological and molecular genetic approaches, we identified kinesin superfamily proteins (KIFs) and characterized their significant functions in intracellular transport, which is fundamental for cellular morphogenesis, functioning, and survival. We showed that KIFs not only transport various membranous organelles, proteins complexes and mRNAs fundamental for cellular functions but also play significant roles in higher brain functions such as memory and learning, determination of important developmental processes such as left-right asymmetry formation and brain wiring. We also elucidated that KIFs recognize and bind to their specific cargoes using scaffolding or adaptor protein complexes. Concerning the mechanism of motility, we discovered the simplest unique monomeric motor KIF1A and determined by molecular biophysics, cryoelectron microscopy and X-ray crystallography that KIF1A can move on a microtubule processively as a monomer by biased Brownian motion and by hydolyzing ATP.

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

    Directory of Open Access Journals (Sweden)

    Del Valle Luis

    2010-06-01

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

  7. Electrical stimulation of gut motility guided by an in silico model

    Science.gov (United States)

    Barth, Bradley B.; Henriquez, Craig S.; Grill, Warren M.; Shen, Xiling

    2017-12-01

    Objective. Neuromodulation of the central and peripheral nervous systems is becoming increasingly important for treating a diverse set of diseases—ranging from Parkinson’s Disease and epilepsy to chronic pain. However, neuromodulation of the gastrointestinal (GI) tract has achieved relatively limited success in treating functional GI disorders, which affect a significant population, because the effects of stimulation on the enteric nervous system (ENS) and gut motility are not well understood. Here we develop an integrated neuromechanical model of the ENS and assess neurostimulation strategies for enhancing gut motility, validated by in vivo experiments. Approach. The computational model included a network of enteric neurons, smooth muscle fibers, and interstitial cells of Cajal, which regulated propulsion of a virtual pellet in a model of gut motility. Main results. Simulated extracellular stimulation of ENS-mediated motility revealed that sinusoidal current at 0.5 Hz was more effective at increasing intrinsic peristalsis and reducing colon transit time than conventional higher frequency rectangular current pulses, as commonly used for neuromodulation therapy. Further analysis of the model revealed that the 0.5 Hz sinusoidal currents were more effective at modulating the pacemaker frequency of interstitial cells of Cajal. To test the predictions of the model, we conducted in vivo electrical stimulation of the distal colon while measuring bead propulsion in awake rats. Experimental results confirmed that 0.5 Hz sinusoidal currents were more effective than higher frequency pulses at enhancing gut motility. Significance. This work demonstrates an in silico GI neuromuscular model to enable GI neuromodulation parameter optimization and suggests that low frequency sinusoidal currents may improve the efficacy of GI pacing.

  8. The beneficial effect of genetically engineered Schwann cells with enhanced motility in peripheral nerve regeneration: review.

    Science.gov (United States)

    Gravvanis, A I; Lavdas, A A; Papalois, A; Tsoutsos, D A; Matsas, R

    2007-01-01

    The importance of Schwann cells in promoting nerve regeneration across a conduit has been extensively reported in the literature, and Schwann cell motility has been acknowledged as a prerequisite for myelination of the peripheral nervous system during regeneration after injury. Review of recent literature and retrospective analysis of our studies with genetically modified Schwann Cells with increased motility in order to identify the underlying mechanism of action and outline the future trends in peripheral nerve repair. Schwann cell transduction with the pREV-retrovirus, for expression of Sialyl-Transferase-X, resulting in conferring Polysialyl-residues (PSA) on NCAM, increases their motility in-vitro and ensures nerve regeneration through silicone tubes after end-to-side neurorraphy in the rat sciatic nerve model, thus significantly promoting fiber maturation and functional outcome. An artificial nerve graft consisting of a type I collagen tube lined with the genetically modified Schwann cells with increased motility, used to bridge a defect in end-to-end fashion in the rat sciatic nerve model, was shown to promote nerve regeneration to a level equal to that of a nerve autograft. The use of genetically engineered Schwann cells with enhanced motility for grafting endoneural tubes promotes axonal regeneration, by virtue of the interaction of the transplanted cells with regenerating axonal growth cones as well as via the recruitment of endogenous Schwann cells. It is envisaged that mixed populations of Schwann cells, expressing PSA and one or more trophic factors, might further enhance the regenerating and remyelinating potential of the lesioned nerves.

  9. TMEM16A inhibition impedes capacitation and acquisition of hyperactivated motility in guinea pig sperm.

    Science.gov (United States)

    Cordero-Martínez, Joaquín; Reyes-Miguel, Tania; Rodríguez-Páez, Lorena; Garduño-Siciliano, Leticia; Maldonado-García, Deneb; Roa-Espitia, Ana L; Hernández-González, Enrique O

    2018-07-01

    Ca 2+ -activated Cl - channels (CaCCs) are anionic channels that regulate many important physiological functions associated with chloride and calcium flux in some somatic cells. The molecular identity of CaCCs was revealed to be TMEM16A and TMEM16B (also known as Anoctamin or ANO1 and ANO2, respectively) in all eukaryotes. A recent study suggests the presence of TMEM16A in human sperm and a relationship with the rhZP-induced acrosome reaction. However, to the best of our knowledge, little is known about the role of TMEM16A in other spermatic processes such as capacitation or motility. In this study, we evaluated the effects of two TMEM16A antagonists on capacitation, acrosome reaction, and motility in guinea pig sperm; these antagonists were T16Ainh-A01, belonging to a second generation of potent antagonists of TMEM16A, and niflumic acid (NFA), a well-known antagonist of TMEM16A (CaCCs). First of all, we confirmed that the absence of Cl - in the capacitation medium changes motility parameters, capacitation, and the progesterone-induced acrosome reaction. Using a specific antibody, TMEM16A was found as a protein band of ∼120 kDa, which localization was in the apical crest of the acrosome and the middle piece of the flagellum. Inhibition of TMEM16A by T16Ainh-A01 affected sperm physiology by reducing capacitation, blocking the progesterone-induced acrosome reaction under optimal capacitation conditions, inhibiting progressive motility, and the acquisition of hyperactivated motility, diminishing [Ca 2+ ]i, and increasing [Cl - ]i. These changes in sperm kinematic parameters provide new evidence of the important role played by TMEM16A in the production of sperm capable of fertilizing oocytes. © 2018 Wiley Periodicals, Inc.

  10. Rational Targeting of Cellular Cholesterol in Diffuse Large B-Cell Lymphoma (DLBCL) Enabled by Functional Lipoprotein Nanoparticles: A Therapeutic Strategy Dependent on Cell of Origin.

    Science.gov (United States)

    Rink, Jonathan S; Yang, Shuo; Cen, Osman; Taxter, Tim; McMahon, Kaylin M; Misener, Sol; Behdad, Amir; Longnecker, Richard; Gordon, Leo I; Thaxton, C Shad

    2017-11-06

    Cancer cells have altered metabolism and, in some cases, an increased demand for cholesterol. It is important to identify novel, rational treatments based on biology, and cellular cholesterol metabolism as a potential target for cancer is an innovative approach. Toward this end, we focused on diffuse large B-cell lymphoma (DLBCL) as a model because there is differential cholesterol biosynthesis driven by B-cell receptor (BCR) signaling in germinal center (GC) versus activated B-cell (ABC) DLBCL. To specifically target cellular cholesterol homeostasis, we employed high-density lipoprotein-like nanoparticles (HDL NP) that can generally reduce cellular cholesterol by targeting and blocking cholesterol uptake through the high-affinity HDL receptor, scavenger receptor type B-1 (SCARB1). As we previously reported, GC DLBCL are exquisitely sensitive to HDL NP as monotherapy, while ABC DLBCL are less sensitive. Herein, we report that enhanced BCR signaling and resultant de novo cholesterol synthesis in ABC DLBCL drastically reduces the ability of HDL NPs to reduce cellular cholesterol and induce cell death. Therefore, we combined HDL NP with the BCR signaling inhibitor ibrutinib and the SYK inhibitor R406. By targeting both cellular cholesterol uptake and BCR-associated de novo cholesterol synthesis, we achieved cellular cholesterol reduction and induced apoptosis in otherwise resistant ABC DLBCL cell lines. These results in lymphoma demonstrate that reduction of cellular cholesterol is a powerful mechanism to induce apoptosis. Cells rich in cholesterol require HDL NP therapy to reduce uptake and molecularly targeted agents that inhibit upstream pathways that stimulate de novo cholesterol synthesis, thus, providing a new paradigm for rationally targeting cholesterol metabolism as therapy for cancer.

  11. Exploratory Research on Latent Esophageal Motility Disorders in Dysphagia Patients.

    Science.gov (United States)

    Kawaguchi, Shinpei; Takeuchi, Toshihisa; Inoue, Yousuke; Takahashi, Yoshiaki; Ozaki, Haruhiko; Ota, Kazuhiro; Harada, Satoshi; Edogawa, Shoko; Kojima, Yuichi; Yamashita, Hiroshi; Fukuchi, Takumi; Ashida, Kiyoshi; Higuchi, Kazuhide

    2017-01-01

    High-resolution manometry (HRM) has been applied to assess esophageal motility disorders. However, the frequency and types of motility disorders in patients with dysphagia, which are frequently seen in clinical practice, are not clear. We evaluated latent esophageal motility disorders associated with dysphagia. The study included patients without erosive esophageal mucosal damage and with dysphagia symptoms refractory to at least 8 weeks of standard-dose proton pump inhibitors. After enrolment, HRM was used to evaluate for esophageal motility disorder based on the Chicago classification. Esophageal motility disorder was found in 58 of 100 patients and was classified based on the causes: achalasia (13%), esophagogastric junction outflow obstruction (16%), distal esophageal spasms (3%), weak peristalsis (14%), frequently failed peristalsis (5%), and hypertensive peristalsis (7%). Primary esophageal motility disorder was found in approximately 50% of cases in dysphagia patients. Therefore, esophageal motility disorder is not an uncommon condition and should be sought for in order to elucidate precisely the cause of dysphagia. © 2017 S. Karger AG, Basel.

  12. Coordination of glioblastoma cell motility by PKCι

    Directory of Open Access Journals (Sweden)

    Baldwin R Mitchell

    2010-09-01

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

  13. The Chicago classification of motility disorders: an update.

    Science.gov (United States)

    Roman, Sabine; Gyawali, C Prakash; Xiao, Yinglian; Pandolfino, John E; Kahrilas, Peter J

    2014-10-01

    The Chicago Classification defines esophageal motility disorders in high resolution manometry. This is based on individual scoring of 10 swallows performed in supine position. Disorders of esophago-gastric junction (EGJ) outflow obstruction are defined by a median integrated relaxation pressure above the limit of normal and divided into 3 achalasia subtypes and EGJ outflow obstruction. Major motility disorders (aperistalsis, distal esophageal spasm, and hypercontractile esophagus) are patterns not encountered in controls in the context of normal EGJ relaxation. Finally with the latest version of the Chicago Classification, only two minor motor disorders are considered: ineffective esophageal motility and fragmented peristalsis. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Bacterial motility in the sea and its ecological implications

    DEFF Research Database (Denmark)

    Grossart, Hans-Peter; Riemann, Lasse; Azam, F.

    2001-01-01

    the coast of La Jolla, California, as well as a mesocosm study to examine bacterial motility and its relationship to environmental variables. Dark-field microscopy revealed periods of sustained low (fall and winter, ...). Bacteria in natural seawater did not swim constantly nor at constant speeds; over 40% swam algae, bacteria...... swimming. Our results show that a variable fraction of marine bacteria is able to respond to loci of organic matter, e.g. organic particles and algae, and that motility underlies dynamic patterns of ecological relationships (symbiosis, competition, parasitism) between bacteria and algae. Since motility may...

  15. Oesophageal motility disorders in patients with psychiatric disease

    Energy Technology Data Exchange (ETDEWEB)

    Roland, J. [Department of Nuclear Medicine, Free University of Brussels, Brussels (Belgium); Dhaenen, H. [Department of Psychiatry, Free University of Brussels, Brussels (Belgium); Ham, H.R. [Department of Nuclear Medicine, Free University of Brussels, Brussels (Belgium); Peters, O. [Department of Gastro-enterology, Free University of Brussels, Brussels (Belgium); Piepsz, A. [Department of Nuclear Medicine, Free University of Brussels, Brussels (Belgium)

    1996-12-01

    Clinical and experimental observations indicate that the motility of the oesophagus may be affected by emotional stimuli. The aim of this study was to evaluate the incidence of oesophageal contractility impairment in patients suffering from a psychiatric disorder. Fifty-one patients admitted to the psychiatric department were submitted to an oesophageal transit study by means of krypton-81m. All patients with an abnormal oesophageal transit underwent manometry and endoscopy. The level of depression and anxiety was evaluated by the treating psychiatrist, using the Hamilton Depression and Anxiety Rating Scales. The oesophageal transit was abnormal in 13 patients. Two of these 13 patients refused manometric investigation. In ten of the 11 remaining patients, the manometry revealed functional motor abnormalities. Endoscopy, performed in all these ten patients, was normal. In conclusion, a high percentage of oesophageal contractility disturbances was found in psychiatric patients complaining of anxiety and/or depression. These abnormalities were detected by scintigraphy as well as by manometry. Owing to the normal endoscopic findings, these contraction abnormalities are likely to reflect a functional motor impairment. (orig.). With 3 figs., 2 tabs.

  16. Oesophageal motility disorders in patients with psychiatric disease

    International Nuclear Information System (INIS)

    Roland, J.; Dhaenen, H.; Ham, H.R.; Peters, O.; Piepsz, A.

    1996-01-01

    Clinical and experimental observations indicate that the motility of the oesophagus may be affected by emotional stimuli. The aim of this study was to evaluate the incidence of oesophageal contractility impairment in patients suffering from a psychiatric disorder. Fifty-one patients admitted to the psychiatric department were submitted to an oesophageal transit study by means of krypton-81m. All patients with an abnormal oesophageal transit underwent manometry and endoscopy. The level of depression and anxiety was evaluated by the treating psychiatrist, using the Hamilton Depression and Anxiety Rating Scales. The oesophageal transit was abnormal in 13 patients. Two of these 13 patients refused manometric investigation. In ten of the 11 remaining patients, the manometry revealed functional motor abnormalities. Endoscopy, performed in all these ten patients, was normal. In conclusion, a high percentage of oesophageal contractility disturbances was found in psychiatric patients complaining of anxiety and/or depression. These abnormalities were detected by scintigraphy as well as by manometry. Owing to the normal endoscopic findings, these contraction abnormalities are likely to reflect a functional motor impairment. (orig.). With 3 figs., 2 tabs

  17. Gastrointestinal symptoms and motility disorders in patients with systemic scleroderma

    Directory of Open Access Journals (Sweden)

    Palasciano Giuseppe

    2008-02-01

    Full Text Available Abstract Background Studies on gastrointestinal symptoms, dysfunctions, and neurological disorders in systemic scleroderma are lacking so far. Methods Thirty-eight scleroderma patients (34 limited, 4 diffuse, 60 healthy controls and 68 dyspeptic controls were scored for upper and lower gastrointestinal symptoms (dyspepsia, bowel habits, gastric and gallbladder emptying to liquid meal (functional ultrasonography and small bowel transit (H2-breath test. Autonomic nerve function was assessed by cardiovascular tests. Results The score for dyspepsia (mainly gastric fullness was greater in scleroderma patients than healthy controls, but lower than dyspeptic controls who had multiple symptoms, instead. Scleroderma patients with dyspepsia had a longer disease duration. Fasting antral area and postprandial antral dilatation were smaller in scleroderma patients than dyspeptic and healthy controls. Gastric emptying was delayed in both scleroderma patients (particularly in those with abnormal dyspeptic score and dyspeptic controls, who also showed a larger residual area. Despite gallbladder fasting and postprandial volumes were comparable across the three groups, gallbladder refilling appeared delayed in dyspeptic controls and mainly dependent on delayed gastric emptying in scleroderma. Small intestinal transit was also delayed in 74% of scleroderma and 66% of dyspeptic controls. Bowel habits were similar among the three groups. Autonomic neuropathy was not associated with dyspepsia, gastric and gallbladder motility and small intestinal transit. Conclusion In scleroderma patients dyspepsia (mainly gastric fullness, restricted distension of the gastric antrum and diffuse gastrointestinal dysmotility are frequent features. These defects are independent from the occurrence of autonomic neuropathy.

  18. PDGF-AA-induced filamentous mitochondria benefit dermal papilla cells in cellular migration.

    Science.gov (United States)

    Mifude, C; Kaseda, K

    2015-06-01

    Human dermal papilla cells (HDPCs) play essential roles in hair follicular morphogenesis and postnatal hair growth cycles. Previous reports demonstrated that platelet-derived growth factor-AA (PDGF-AA) enhanced the formation of dermal condensates in hair follicular development. Additionally, PDGF-AA induces/maintains the anagen phase of the hair cycle. It is likely that mitochondrial morphology and functions are tightly coupled with maintenance of these energy-demanding activities. However, little is known about the mitochondrial regulation in HDPCs. Thus, we investigated the PDGF-involved mitochondrial regulation in HDPCs. The mitochondrial morphologies of HDPCs were examined in the presence or absence of PDGF-AA under a fluorescent microscope. ATP production and cellular motility were investigated. The relationship between mitochondrial morphology and the cellular functions was discussed. We observed that primary HDPCs contained mitochondria with filamentous and/or rounded morphologies. Both types of mitochondria showed similar membrane potentials. Interestingly, in the presence of PDGF-AA, but not PDGF-BB, the balance between the two morphologies shifted towards the filamentous form. Concomitantly, both mitochondrial enzymatic activity and total cellular ATP level were augmented by PDGF-AA. These two parameters were closely correlated, suggesting the mitochondrial involvement in the PDGF-augmented ATP production. Moreover, PDGF-AA accelerated the migration of HDPCs in a gap-filling assay, but did not change the rate of cellular proliferation. Notably, filamentous mitochondria dominated migrating HDPCs. PDGF-AA benefits HDPCs in the process of migration, by increasing the number of filamentous mitochondria. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  19. Novel Materials for Cellular Nanosensors

    DEFF Research Database (Denmark)

    Sasso, Luigi

    The monitoring of cellular behavior is useful for the advancement of biomedical diagnostics, drug development and the understanding of a cell as the main unit of the human body. Micro- and nanotechnology allow for the creation of functional devices that enhance the study of cellular dynamics...... modifications for electrochemical nanosensors for the detection of analytes released from cells. Two type of materials were investigated, each pertaining to the two different aspects of such devices: peptide nanostructures were studied for the creation of cellular sensing substrates that mimic in vivo surfaces...... and that offer advantages of functionalization, and conducting polymers were used as electrochemical sensor surface modifications for increasing the sensitivity towards relevant analytes, with focus on the detection of dopamine released from cells via exocytosis. Vertical peptide nanowires were synthesized from...

  20. High-Resolution Manometry Evaluation of the Pharynx and Upper Esophageal Sphincter Motility in Patients with Achalasia.

    Science.gov (United States)

    Menezes, Mariano A; Herbella, Fernando A M; Patti, Marco G

    2015-10-01

    The motility of the pharynx and upper esophageal sphincter (UES) is still poorly understood. It is also unclear if the motility of this area may be compromised in patients with achalasia. This study aims to evaluate the motility of the pharynx, UES, and proximal esophagus in patients with esophageal achalasia. Sixty patients with achalasia underwent high-resolution manometry (HRM) (52 % females, mean age 54 years). Esophageal dilatation was classified according to the radiologic diameter in Type I (10 cm): 24 %. HRM classified 43 % of the patients as Chicago Type I and 57 % as Type II. Manometric parameters were compared to normal values obtained from a previous study in volunteers. The motility of the velopharynx showed short, premature, and hypertonic contraction. The epiglottis also showed hypertonic contraction. The UES had increased residual pressure. Chicago classification Type II patients had higher UES residual pressure (p = 0.03). The degree of esophageal dilatation did not correlate with manometric parameters. Achalasia may affect the motility of the pharyngo-upper esophageal area. The changes observed may represent functional alterations to prevent aspiration, especially in patients with Chicago classification Type II achalasia.

  1. Sperm motility of externally fertilizing fish and amphibians.

    Science.gov (United States)

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

    2015-01-01

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

  2. Appearance and dynamics of rumen motility in newborn calves

    International Nuclear Information System (INIS)

    Kostov, Y.; Aleksandrova, V.

    2010-01-01

    The appearance and dynamics of rumen motility in newborn calves were studied by means of radiotelemetry. Rumen contractions were registered right after birth. Their amplitude was growing gradually and that was observed best in the first month after birth

  3. Thioredoxin A Is Essential for Motility and Contributes to Host Infection of Listeria monocytogenes via Redox Interactions

    Directory of Open Access Journals (Sweden)

    Changyong Cheng

    2017-06-01

    Full Text Available Microbes employ the thioredoxin system to defend against oxidative stress and ensure correct disulfide bonding to maintain protein function. Listeria monocytogenes has been shown to encode a putative thioredoxin, TrxA, but its biological roles and underlying mechanisms remain unknown. Here, we showed that expression of L. monocytogenes TrxA is significantly induced in bacteria treated with the thiol-specific oxidizing agent, diamide. Deletion of trxA markedly compromised tolerance of the pathogen to diamide, and mainly impaired early stages of infection in human intestinal epithelial Caco-2 cells. In addition, most trxA mutant bacteria were not associated with polymerized actin, and the rare bacteria that were associated with polymerized actin displayed very short tails or clouds during infection. Deletion or constitutive overexpression of TrxA, which was regulated by SigH, severely attenuated the virulence of the pathogen. Transcriptome analysis of L. monocytogenes revealed over 270 genes that were differentially transcribed in the ΔtrxA mutant compared to the wild-type, especially for the virulence-associated genes plcA, mpl, hly, actA, and plcB. Particularly, deletion of TrxA completely reduced LLO expression, and thereby led to a thoroughly impaired hemolytic activity. Expression of these virulence factors are positively regulated by the master regulator PrfA that was found here to use TrxA to maintain its reduced forms for activation. Interestingly, the trxA deletion mutant completely lacked flagella and was non-motile. We further confirmed that this deficiency is attributable to TrxA in maintaining the reduced intracellular monomer status of MogR, the key regulator for flagellar formation, to ensure correct dimerization. In summary, we demonstrated for the first time that L. monocytogenes thioredoxin A as a vital cellular reductase is essential for maintaining a highly reducing environment in the bacterial cytosol, which provides a

  4. Thioredoxin A Is Essential for Motility and Contributes to Host Infection of Listeria monocytogenes via Redox Interactions.

    Science.gov (United States)

    Cheng, Changyong; Dong, Zhimei; Han, Xiao; Wang, Hang; Jiang, Li; Sun, Jing; Yang, Yongchun; Ma, Tiantian; Shao, Chunyan; Wang, Xiaodu; Chen, Zhongwei; Fang, Weihuan; Freitag, Nancy E; Huang, Huarong; Song, Houhui

    2017-01-01

    Microbes employ the thioredoxin system to defend against oxidative stress and ensure correct disulfide bonding to maintain protein function. Listeria monocytogenes has been shown to encode a putative thioredoxin, TrxA, but its biological roles and underlying mechanisms remain unknown. Here, we showed that expression of L. monocytogenes TrxA is significantly induced in bacteria treated with the thiol-specific oxidizing agent, diamide. Deletion of trxA markedly compromised tolerance of the pathogen to diamide, and mainly impaired early stages of infection in human intestinal epithelial Caco-2 cells. In addition, most trxA mutant bacteria were not associated with polymerized actin, and the rare bacteria that were associated with polymerized actin displayed very short tails or clouds during infection. Deletion or constitutive overexpression of TrxA, which was regulated by SigH, severely attenuated the virulence of the pathogen. Transcriptome analysis of L. monocytogenes revealed over 270 genes that were differentially transcribed in the Δ trxA mutant compared to the wild-type, especially for the virulence-associated genes plcA, mpl, hly, actA , and plcB . Particularly, deletion of TrxA completely reduced LLO expression, and thereby led to a thoroughly impaired hemolytic activity. Expression of these virulence factors are positively regulated by the master regulator PrfA that was found here to use TrxA to maintain its reduced forms for activation. Interestingly, the trxA deletion mutant completely lacked flagella and was non-motile. We further confirmed that this deficiency is attributable to TrxA in maintaining the reduced intracellular monomer status of MogR, the key regulator for flagellar formation, to ensure correct dimerization. In summary, we demonstrated for the first time that L. monocytogenes thioredoxin A as a vital cellular reductase is essential for maintaining a highly reducing environment in the bacterial cytosol, which provides a favorable condition for

  5. An automatic system to study sperm motility and energetics

    OpenAIRE

    Shi, LZ; Nascimento, JM; Chandsawangbhuwana, C; Botvinick, EL; Berns, MW

    2008-01-01

    An integrated robotic laser and microscope system has been developed to automatically analyze individual sperm motility and energetics. The custom-designed optical system directs near-infrared laser light into an inverted microscope to create a single-point 3-D gradient laser trap at the focal spot of the microscope objective. A two-level computer structure is described that quantifies the sperm motility (in terms of swimming speed and swimming force) and energetics (measuring mid-piece membr...

  6. Neural network for automatic analysis of motility data

    DEFF Research Database (Denmark)

    Jakobsen, Erik; Kruse-Andersen, S; Kolberg, Jens Godsk

    1994-01-01

    comparable. However, the neural network recognized pressure peaks clearly generated by muscular activity that had escaped detection by the conventional program. In conclusion, we believe that neurocomputing has potential advantages for automatic analysis of gastrointestinal motility data.......Continuous recording of intraluminal pressures for extended periods of time is currently regarded as a valuable method for detection of esophageal motor abnormalities. A subsequent automatic analysis of the resulting motility data relies on strict mathematical criteria for recognition of pressure...

  7. Redox reaction triggered nanomotors based on soft-oxometalates with high and sustained motility

    Science.gov (United States)

    Mallick, Apabrita; Laskar, Abhrajit; Adhikari, R.; Roy, Soumyajit

    2018-05-01

    The recent interest in self-propulsion raises an immediate challenge in facile and single-step synthesis of active particles. Here, we address this challenge and synthesize soft oxometalate nanomotors that translate ballistically in water using the energy released in a redox reaction of hydrazine fuel with the soft-oxometalates. Our motors reach a maximum speed of ̴ 370 body lengths per second and remain motile over a period of approximately three days. We report measurements of the speed of a single motor as a function of the concentration of hydrazine. It is also possible to induce a transition from single-particle translation to collective motility with biomimetic bands simply by tuning the loading of the fuel. We rationalize the results from a physicochemical hydrodynamic theory. Our nanomotors may also be used for transport of catalytic materials in harsh chemical environments that would otherwise passivate the active catalyst.

  8. Kinesin-1 and mitochondrial motility control by discrimination of structurally equivalent but distinct subdomains in Ran-GTP-binding domains of Ran-binding protein 2.

    Science.gov (United States)

    Patil, Hemangi; Cho, Kyoung-in; Lee, James; Yang, Yi; Orry, Andrew; Ferreira, Paulo A

    2013-03-27

    The pleckstrin homology (PH) domain is a versatile fold that mediates a variety of protein-protein and protein-phosphatidylinositol lipid interactions. The Ran-binding protein 2 (RanBP2) contains four interspersed Ran GTPase-binding domains (RBD(n = 1-4)) with close structural homology to the PH domain of Bruton's tyrosine kinase. The RBD2, kinesin-binding domain (KBD) and RBD3 comprise a tripartite domain (R2KR3) of RanBP2 that causes the unfolding, microtubule binding and biphasic activation of kinesin-1, a crucial anterograde motor of mitochondrial motility. However, the interplay between Ran GTPase and R2KR3 of RanBP2 in kinesin-1 activation and mitochondrial motility is elusive. We use structure-function, biochemical, kinetic and cell-based assays with time-lapse live-cell microscopy of over 260,000 mitochondrial-motility-related events to find mutually exclusive subdomains in RBD2 and RBD3 towards Ran GTPase binding, kinesin-1 activation and mitochondrial motility regulation. The RBD2 and RBD3 exhibit Ran-GTP-independent, subdomain and stereochemical-dependent discrimination on the biphasic kinetics of kinesin-1 activation or regulation of mitochondrial motility. Further, KBD alone and R2KR3 stimulate and suppress, respectively, multiple biophysical parameters of mitochondrial motility. The regulation of the bidirectional transport of mitochondria by either KBD or R2KR3 is highly coordinated, because their kinetic effects are accompanied always by changes in mitochondrial motile events of either transport polarity. These studies uncover novel roles in Ran GTPase-independent subdomains of RBD2 and RBD3, and KBD of RanBP2, that confer antagonizing and multi-modal mechanisms of kinesin-1 activation and regulation of mitochondrial motility. These findings open new venues towards the pharmacological harnessing of cooperative and competitive mechanisms regulating kinesins, RanBP2 or mitochondrial motility in disparate human disorders.

  9. Alternative Splicing in Adhesion- and Motility-Related Genes in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Rosanna Aversa

    2016-01-01

    Full Text Available Breast cancer is the most common tumor and the second leading cause of cancer death among woman, mainly caused by the metastatic spread. Tumor invasiveness is due to an altered expression of adhesion molecules. Among them, semaphorins are of peculiar interest. Cancer cells can manipulate alternative splicing patterns to modulate the expression of adhesion- and motility-related molecules, also at the isoform level. In this study, combining RNA-Sequencing on MCF-7 to targeted experimental validations—in human breast cell lines and breast tumor biopsies—we identified 12 new alternative splicing transcripts in genes encoding adhesion- and motility-related molecules, including semaphorins, their receptors and co-receptors. Among them, a new SEMA3F transcript is expressed in all breast cell lines and breast cancer biopsies, and is translated into a new semaphorin 3F isoform. In silico analysis predicted that most of the new putative proteins lack functional domains, potentially missing some functions and acquiring new ones. Our findings better describe the extent of alternative splicing in breast cancer and highlight the need to further investigate adhesion- and motility-related molecules to gain insights into breast cancer progression.

  10. Microfabricated ratchet structures for concentrating and patterning motile bacterial cells

    International Nuclear Information System (INIS)

    Kim, Sang Yub; Lee, Eun Se; Lee, Ho Jae; Lee, Se Yeon; Lee, Sung Kuk; Kim, Taesung

    2010-01-01

    We present a novel microfabricated concentrator for Escherichia coli that can be a stand-alone and self-contained microfluidic device because it utilizes the motility of cells. First of all, we characterize the motility of E. coli cells and various ratcheting structures that can guide cells to move in a desired direction in straight and circular channels. Then, we combine these ratcheting microstructures with the intrinsic tendency of cells to swim on the right side in microchannels to enhance the concentration rates up to 180 fold until the concentrators are fully filled with cells. Furthermore, we demonstrate that cells can be positioned and concentrated with a constant spacing distance on a surface, allowing spatial patterning of motile cells. These results can be applied to biosorption or biosensor devices that are powered by motile cells because they can be highly concentrated without any external mechanical and electrical energy sources. Hence, we believe that the concentrator design holds considerable potential to be applied for concentrating and patterning other motile microbes and providing a versatile structure for motility study of bacterial cells.

  11. Automatic Bowel Motility Evaluation Technique for Noncontact Sound Recordings

    Directory of Open Access Journals (Sweden)

    Ryunosuke Sato

    2018-06-01

    Full Text Available Information on bowel motility can be obtained via magnetic resonance imaging (MRIs and X-ray imaging. However, these approaches require expensive medical instruments and are unsuitable for frequent monitoring. Bowel sounds (BS can be conveniently obtained using electronic stethoscopes and have recently been employed for the evaluation of bowel motility. More recently, our group proposed a novel method to evaluate bowel motility on the basis of BS acquired using a noncontact microphone. However, the method required manually detecting BS in the sound recordings, and manual segmentation is inconvenient and time consuming. To address this issue, herein, we propose a new method to automatically evaluate bowel motility for noncontact sound recordings. Using simulations for the sound recordings obtained from 20 human participants, we showed that the proposed method achieves an accuracy of approximately 90% in automatic bowel sound detection when acoustic feature power-normalized cepstral coefficients are used as inputs to artificial neural networks. Furthermore, we showed that bowel motility can be evaluated based on the three acoustic features in the time domain extracted by our method: BS per minute, signal-to-noise ratio, and sound-to-sound interval. The proposed method has the potential to contribute towards the development of noncontact evaluation methods for bowel motility.

  12. Inter-observer agreement for diagnostic classification of esophageal motility disorders defined in high-resolution manometry

    NARCIS (Netherlands)

    Fox, M. R.; Pandolfino, J. E.; Sweis, R.; Sauter, M.; Abreu Y Abreu, A. T.; Anggiansah, A.; Bogte, A.; Bredenoord, A. J.; Dengler, W.; Elvevi, A.; Fruehauf, H.; Gellersen, S.; Ghosh, S.; Gyawali, C. P.; Heinrich, H.; Hemmink, M.; Jafari, J.; Kaufman, E.; Kessing, K.; Kwiatek, M.; Lubomyr, B.; Banasiuk, M.; Mion, F.; Pérez-de-la-Serna, J.; Remes-Troche, J. M.; Rohof, W.; Roman, S.; Ruiz-de-León, A.; Tutuian, R.; Uscinowicz, M.; Valdovinos, M. A.; Vardar, R.; Velosa, M.; Waśko-Czopnik, D.; Weijenborg, P.; Wilshire, C.; Wright, J.; Zerbib, F.; Menne, D.

    2015-01-01

    High-resolution esophageal manometry (HRM) is a recent development used in the evaluation of esophageal function. Our aim was to assess the inter-observer agreement for diagnosis of esophageal motility disorders using this technology. Practitioners registered on the HRM Working Group website were

  13. Curriculum for neurogastroenterology and motility training: A report from the joint ANMS-ESNM task force.

    Science.gov (United States)

    Gyawali, C P; Savarino, E; Lazarescu, A; Bor, S; Patel, A; Dickman, R; Pressman, A; Drewes, A M; Rosen, J; Drug, V; Saps, M; Novais, L; Vazquez-Roque, M; Pohl, D; van Tilburg, M A L; Smout, A; Yoon, S; Pandolfino, J; Farrugia, G; Barbara, G; Roman, S

    2018-03-25

    Although neurogastroenterology and motility (NGM) disorders are some of the most frequent disorders encountered by practicing gastroenterologists, a structured competency-based training curriculum developed by NGM experts is lacking. The American Neurogastroenterology and Motility Society (ANMS) and the European Society of Neurogastroenterology and Motility (ESNM) jointly evaluated the components of NGM training in North America and Europe. Eleven training domains were identified within NGM, consisting of functional gastrointestinal disorders, visceral hypersensitivity and pain pathways, motor disorders within anatomic areas (esophagus, stomach, small bowel and colon, anorectum), mucosal disorders (gastro-esophageal reflux disease, other mucosal disorders), consequences of systemic disease, consequences of therapy (surgery, endoscopic intervention, medications, other therapy), and transition of pediatric patients into adult practice. A 3-tiered training curriculum covering these domains is proposed here and endorsed by all NGM societies. Tier 1 NGM knowledge and training is expected of all gastroenterology trainees and practicing gastroenterologists. Tier 2 knowledge and training is appropriate for trainees who anticipate NGM disorder management and NGM function test interpretation being an important part of their careers, which may require competency assessment and credentialing of test interpretation skills. Tier 3 knowledge and training is undertaken by trainees interested in a dedicated NGM career and may be restricted to specific domains within the broad NGM field. The joint ANMS and ESNM task force anticipates that the NGM curriculum will streamline NGM training in North America and Europe and will lead to better identification of centers of excellence where Tier 2 and Tier 3 training can be accomplished. © 2018 The Authors. Neurogastroenterology & Motility Published by John Wiley & Sons, Ltd.

  14. Podoplanin promotes progression of malignant pleural mesothelioma by regulating motility and focus formation.

    Science.gov (United States)

    Takeuchi, Shinji; Fukuda, Koji; Yamada, Tadaaki; Arai, Sachiko; Takagi, Satoshi; Ishii, Genichiro; Ochiai, Atsushi; Iwakiri, Shotaro; Itoi, Kazumi; Uehara, Hisanori; Nishihara, Hiroshi; Fujita, Naoya; Yano, Seiji

    2017-04-01

    Malignant pleural mesothelioma (MPM) is characterized by dissemination and aggressive growth in the thoracic cavity. Podoplanin (PDPN) is an established diagnostic marker for MPM, but the function of PDPN in MPM is not fully understood. The purpose of this study was to determine the pathogenetic function of PDPN in MPM. Forty-seven of 52 tumors (90%) from Japanese patients with MPM and 3/6 (50%) MPM cell lines tested positive for PDPN. Knocking down PDPN in PDPN-high expressing MPM cells resulted in decreased cell motility. In contrast, overexpression of PDPN in PDPN-low expressing MPM cells enhanced cell motility. PDPN stimulated motility was mediated by activation of the RhoA/ROCK pathway. Moreover, knocking down PDPN with short hairpin (sh) RNA in PDPN-high expressing MPM cells resulted in decreased development of a thoracic tumor in mice with severe combined immune deficiency (SCID). In sharp contrast, transfection of PDPN in PDPN-low expressing MPM cells resulted in an increase in the number of Ki-67-positive proliferating tumor cells and it promoted progression of a thoracic tumor in SCID mice. Interestingly, PDPN promoted focus formation in vitro, and a low level of E-cadherin expression and YAP1 activation was observed in PDPN-high MPM tumors. These findings indicate that PDPN is a diagnostic marker as well as a pathogenetic regulator that promotes MPM progression by increasing cell motility and inducing focus formation. Therefore, PDPN might be a pathogenetic determinant of MPM dissemination and aggressive growth and may thus be an ideal therapeutic target. © 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  15. Exosome secretion affects social motility in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Dror Eliaz

    2017-03-01

    Full Text Available Extracellular vesicles (EV secreted by pathogens function in a variety of biological processes. Here, we demonstrate that in the protozoan parasite Trypanosoma brucei, exosome secretion is induced by stress that affects trans-splicing. Following perturbations in biogenesis of spliced leader RNA, which donates its spliced leader (SL exon to all mRNAs, or after heat-shock, the SL RNA is exported to the cytoplasm and forms distinct granules, which are then secreted by exosomes. The exosomes are formed in multivesicular bodies (MVB utilizing the endosomal sorting complexes required for transport (ESCRT, through a mechanism similar to microRNA secretion in mammalian cells. Silencing of the ESCRT factor, Vps36, compromised exosome secretion but not the secretion of vesicles derived from nanotubes. The exosomes enter recipient trypanosome cells. Time-lapse microscopy demonstrated that cells secreting exosomes or purified intact exosomes affect social motility (SoMo. This study demonstrates that exosomes are delivered to trypanosome cells and can change their migration. Exosomes are used to transmit stress signals for communication between parasites.

  16. Depression and embodiment: phenomenological reflections on motility, affectivity, and transcendence.

    Science.gov (United States)

    Aho, Kevin A

    2013-11-01

    This paper integrates personal narratives with the methods of phenomenology in order to draw some general conclusions about 'what it means' and 'what it feels like' to be depressed. The analysis has three parts. First, it explores the ways in which depression disrupts everyday experiences of spatial orientation and motility. This disruption makes it difficult for the person to move and perform basic functional tasks, resulting in a collapse or contraction of the life-world. Second, it illustrates how depression creates a situational atmosphere of emotional indifference that reduces the person's ability to qualitatively distinguish what matters in his or her life because nothing stands out as significant or important anymore. In this regard, depression is distinct from other feelings because it is not directed towards particular objects or situations but to the world as a whole. Finally, the paper examines how depression diminishes the possibility for 'self-creation' or 'self-making'. Restricted by the illness, depression becomes something of a destiny, preventing the person from being open and free to access a range of alternative self-interpretations, identities, and possible ways of being-in-the-world.

  17. L-Plastin promotes podosome longevity and supports macrophage motility

    Science.gov (United States)

    Zhou, Julie Y.; Szasz, Taylor P.; Stewart-Hutchinson, Phillip J.; Sivapalan, Janardan; Todd, Elizabeth M.; Deady, Lauren E.; Cooper, John A.; Onken, Michael D.; Morley, S. Celeste

    2016-01-01

    Elucidating the molecular regulation of macrophage migration is essential for understanding the patho-physiology of multiple human diseases, including host responses to infection and autoimmune disorders. Macrophage migration is supported by dynamic rearrangements of the actin cytoskeleton, with formation of actin-based structures such as podosomes and lamellipodia. Here we provide novel insights into the function of the actin-bundling protein l-plastin (LPL) in primary macrophages. We found that podosome stability is disrupted in primary resident peritoneal macrophages from LPL−/− mice. Live-cell imaging of F-actin using resident peritoneal macrophages from LifeACT-RFP+ mice demonstrated that loss of LPL led to decreased longevity of podosomes, without reducing the number of podosomes initiated. Additionally, macrophages from LPL−/− mice failed to elongate in response to chemotactic stimulation. These deficiencies in podosome stabilization and in macrophage elongation correlated with impaired macrophage transmigration in culture and decreased monocyte migration into murine peritoneum. Thus, we have identified a role for LPL in stabilizing long-lived podosomes and in enabling macrophage motility. PMID:27614263

  18. Comparison of orbital prosthesis motility following enucleation or evisceration with sclerotomy with or without a motility coupling post in dogs.

    Science.gov (United States)

    Yi, Na Young; Park, Shin Ae; Jeong, Man Bok; Kim, Won Tae; Kim, Se Eun; Kim, Ji Youn; Chae, Je Min; Jang, Kyoung Jin; Seong, Je Kyung; Seo, Kang Moon

    2009-01-01

    To evaluate motility of silicone orbital implants and corneoscleral prostheses, with and without use of a motility coupling post (MCP) in dogs. Eighteen mixed-breed dogs. The motility of an orbital silicone implant and corneoscleral prosthesis after enucleation (n = 6), evisceration (n = 6), or use of a MCP with evisceration (n = 6) in dogs were compared. One eye from each dog had surgery whereas the opposite eye was used as a control. Clinical evaluations were performed three times a week. Histopathology of the orbital tissues was performed 8 and 12 weeks after surgery. Implant motility in dogs with evisceration (vertical movement [VM] 8.04 +/- 2.13; horizontal movement [HM] 11 +/- 3.05) and evisceration with MCP (VM 9.61 +/- 1.59); HM was significantly greater than the enucleation group (VM 0.51 +/- 0.5; HM 1.22 +/- 0.68) (P dogs with evisceration with MCP was significantly greater than in dogs with evisceration; dogs with evisceration had significantly greater motility than dogs with enucleation (P dogs. This study supports the use of MCP in silicone orbital implants to enhance corneoscleral prosthesis motility and cosmetics in dogs.

  19. Cellular Adhesion and Adhesion Molecules

    OpenAIRE

    SELLER, Zerrin

    2014-01-01

    In recent years, cell adhesion and cell adhesion molecules have been shown to be important for many normal biological processes, including embryonic cell migration, immune system functions and wound healing. It has also been shown that they contribute to the pathogenesis of a large number of common human disorders, such as rheumatoid arthritis and tumor cell metastasis in cancer. In this review, the basic mechanisms of cellular adhesion and the structural and functional features of adhes...

  20. Sperm motility and morphology as changing parameters linked to sperm count variations.

    OpenAIRE

    Dua A; Vaidya S

    1996-01-01

    Variations in semen analyses of 177 males over a 1 year period were assessed. The average means of total counts, motility, morphology, total motile count and non-motile % were determined for 5 classes of patients ranging from azoospermic to normospermic. Positive relationships between a falling sperm count, a decrease in motility and total motile counts were seen. Also, increasingly, abnormal forms were found with lower sperm counts.

  1. Sperm motility and morphology as changing parameters linked to sperm count variations.

    Directory of Open Access Journals (Sweden)

    Dua A

    1996-10-01

    Full Text Available Variations in semen analyses of 177 males over a 1 year period were assessed. The average means of total counts, motility, morphology, total motile count and non-motile % were determined for 5 classes of patients ranging from azoospermic to normospermic. Positive relationships between a falling sperm count, a decrease in motility and total motile counts were seen. Also, increasingly, abnormal forms were found with lower sperm counts.

  2. Quantitative assessment of cancer cell morphology and motility using telecentric digital holographic microscopy and machine learning.

    Science.gov (United States)

    Lam, Van K; Nguyen, Thanh C; Chung, Byung M; Nehmetallah, George; Raub, Christopher B

    2018-03-01

    The noninvasive, fast acquisition of quantitative phase maps using digital holographic microscopy (DHM) allows tracking of rapid cellular motility on transparent substrates. On two-dimensional surfaces in vitro, MDA-MB-231 cancer cells assume several morphologies related to the mode of migration and substrate stiffness, relevant to mechanisms of cancer invasiveness in vivo. The quantitative phase information from DHM may accurately classify adhesive cancer cell subpopulations with clinical relevance. To test this, cells from the invasive breast cancer MDA-MB-231 cell line were cultured on glass, tissue-culture treated polystyrene, and collagen hydrogels, and imaged with DHM followed by epifluorescence microscopy after staining F-actin and nuclei. Trends in cell phase parameters were tracked on the different substrates, during cell division, and during matrix adhesion, relating them to F-actin features. Support vector machine learning algorithms were trained and tested using parameters from holographic phase reconstructions and cell geometric features from conventional phase images, and used to distinguish between elongated and rounded cell morphologies. DHM was able to distinguish between elongated and rounded morphologies of MDA-MB-231 cells with 94% accuracy, compared to 83% accuracy using cell geometric features from conventional brightfield microscopy. This finding indicates the potential of DHM to detect and monitor cancer cell morphologies relevant to cell cycle phase status, substrate adhesion, and motility. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

  3. Cell-cycle-dependent regulation of cell motility and determination of the role of Rac1

    DEFF Research Database (Denmark)

    Walmod, Peter S.; Hartmann-Petersen, Rasmus; Prag, S.

    2004-01-01

    comparable to those of control cells in G1. In contrast, transfection with dominant-negative Rac1 reduced cell speed and resulted in cellular displacements, which were identical in G1 and G2. These observations indicate that migration of cultured cells is regulated in a cell-cycle-dependent manner...... for calculation of three key parameters describing cell motility: speed, persistence time and rate of diffusion. All investigated cell lines demonstrated a lower cell displacement in the G2 phase than in the G1/S phases. This was caused by a decrease in speed and/or persistence time. The decrease in motility...... was accompanied by changes in morphology reflecting the larger volume of cells in G2 than in G1. Furthermore, L-cells and HeLa-cells appeared to be less adherent in the G2 phase. Transfection of L-cells with constitutively active Rac1 led to a general increase in the speed and rate of diffusion in G2 to levels...

  4. The Diguanylate Cyclase HsbD Intersects with the HptB Regulatory Cascade to Control Pseudomonas aeruginosa Biofilm and Motility.

    Directory of Open Access Journals (Sweden)

    Martina Valentini

    2016-10-01

    Full Text Available The molecular basis of second messenger signaling relies on an array of proteins that synthesize, degrade or bind the molecule to produce coherent functional outputs. Cyclic di-GMP (c-di-GMP has emerged as a eubacterial nucleotide second messenger regulating a plethora of key behaviors, like the transition from planktonic cells to biofilm communities. The striking multiplicity of c-di-GMP control modules and regulated cellular functions raised the question of signaling specificity. Are c-di-GMP signaling routes exclusively dependent on a central hub or can they be locally administrated? In this study, we show an example of how c-di-GMP signaling gains output specificity in Pseudomonas aeruginosa. We observed the occurrence in P. aeruginosa of a c-di-GMP synthase gene, hsbD, in the proximity of the hptB and flagellar genes cluster. We show that the HptB pathway controls biofilm formation and motility by involving both HsbD and the anti-anti-sigma factor HsbA. The rewiring of c-di-GMP signaling into the HptB cascade relies on the original interaction between HsbD and HsbA and on the control of HsbD dynamic localization at the cell poles.

  5. Persistent enhancement of bacterial motility increases tumor penetration.

    Science.gov (United States)

    Thornlow, Dana N; Brackett, Emily L; Gigas, Jonathan M; Van Dessel, Nele; Forbes, Neil S

    2015-11-01

    Motile bacteria can overcome the transport limitations that hinder many cancer therapies. Active bacteria can penetrate through tissue to deliver treatment to resistant tumor regions. Bacterial therapy has had limited success, however, because this motility is heterogeneous, and within a population many individuals are non-motile. In human trials, heterogeneity led to poor dispersion and incomplete tumor colonization. To address these problems, a swarm-plate selection method was developed to increase swimming velocity. Video microscopy was used to measure the velocity distribution of selected bacteria and a microfluidic tumor-on-a-chip device was used to measure penetration through tumor cell masses. Selection on swarm plates increased average velocity fourfold, from 4.9 to 18.7 μm/s (P < 0.05) and decreased the number of non-motile individuals from 51% to 3% (P < 0.05). The selected phenotype was both robust and stable. Repeating the selection process consistently increased velocity and eliminated non-motile individuals. When selected strains were cryopreserved and subcultured for 30.1 doublings, the high-motility phenotype was preserved. In the microfluidic device, selected Salmonella penetrated deeper into cell masses than unselected controls. By 10 h after inoculation, control bacteria accumulated in the front 30% of cell masses, closest to the flow channel. In contrast, selected Salmonella accumulated in the back 30% of cell masses, farthest from the channel. Selection increased the average penetration distance from 150 to 400 μm (P < 0.05). This technique provides a simple and rapid method to generate high-motility Salmonella that has increased penetration and potential for greater tumor dispersion and clinical efficacy. © 2015 Wiley Periodicals, Inc.

  6. PTP1B inhibitor promotes endothelial cell motility by activating the DOCK180/Rac1 pathway.

    Science.gov (United States)

    Wang, Yuan; Yan, Feng; Ye, Qing; Wu, Xiao; Jiang, Fan

    2016-04-07

    Promoting endothelial cell (EC) migration is important not only for therapeutic angiogenesis, but also for accelerating re-endothelialization after vessel injury. Several recent studies have shown that inhibition of protein tyrosine phosphatase 1B (PTP1B) may promote EC migration and angiogenesis by enhancing the vascular endothelial growth factor receptor-2 (VEGFR2) signalling. In the present study, we demonstrated that PTP1B inhibitor could promote EC adhesion, spreading and migration, which were abolished by the inhibitor of Rac1 but not RhoA GTPase. PTP1B inhibitor significantly increased phosphorylation of p130Cas, and the interactions among p130Cas, Crk and DOCK180; whereas the phosphorylation levels of focal adhesion kinase, Src, paxillin, or Vav2 were unchanged. Gene silencing of DOCK180, but not Vav2, abrogated the effects of PTP1B inhibitor on EC motility. The effects of PTP1B inhibitor on EC motility and p130Cas/DOCK180 activation persisted in the presence of the VEGFR2 antagonist. In conclusion, we suggest that stimulation of the DOCK180 pathway represents an alternative mechanism of PTP1B inhibitor-stimulated EC motility, which does not require concomitant VEGFR2 activation as a prerequisite. Therefore, PTP1B inhibitor may be a useful therapeutic strategy for promoting EC migration in cardiovascular patients in which the VEGF/VEGFR functions are compromised.

  7. Radiological evaluation of esophageal motility and gastroesophageal reflux disease; Funktionsstoerungen des Oesophagus. Radiologische Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Schima, W. [Abt. Roentgen fuer Konservative Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Pokieser, P. [Abt. Roentgen fuer Chirurgische Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria); Schober, E. [Abt. Roentgen fuer Konservative Faecher, Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    1995-10-01

    Radiological evaluation of esophageal motility and the lower esophageal sphincter has gained increased attention in recent years. Videofluoroscopic investigation of esophageal motor function is superior to static film radiography, as repeated analysis of the videotaped recordings is possible. With emphasis on radiological techniques, normal esophagel physiology and motility and a variety of esophageal motor disorders are discussed in this review paper. Radiological evaluation of gastroesophageal reflux and reflux esophagitis is described. Clinical and radiological findings in esophageal motility disorders and gastroesophageal reflux disease and the radiological efficacy compared to that of manometry and pH-metry are discussed. (orig.) [Deutsch] Die radiologische Untersuchung des Oesophagus kann nicht nur strukturelle Veraenderungen, sondern auch funktionelle Stoerungen mit einer hohen Treffsicherheit nachweisen. Die Videokinematographie ist hierbei der konventionellen Roentgenuntersuchung aufgrund der Moeglichkeit der wiederholten Analyse ueberlegen. Ziel der vorliegenden Uebersicht ist es, prinzipiell das radiologische Erscheinungsbild der normalen Funktion sowie diagnostische Kriterien fuer verschiedene Motilitaetsstoerungen zu demonstrieren. Weiterhin werden auch die verschiedenen Moeglichkeiten der radiologischen Refluxpruefung zur Untersuchung der Funktion des gastrooesophagealen Sphinkters verglichen und deren Wert diskutiert. Die Pruefung der Funktion von Oesophagus und gastrooesophagealem Sphinkter als ein integraler Bestandteil der Roentgenuntersuchung der Speiseroehre verbessert deren Treffsicherheit, wodurch die radiologische Untersuchung die primaere diagnostische Methode bei Patienten mit Schluckstoerungen darstellt. (orig.)

  8. Direct Correlation between Motile Behavior and Protein Abundance in Single Cells.

    Directory of Open Access Journals (Sweden)

    Yann S Dufour

    2016-09-01

    Full Text Available Understanding how stochastic molecular fluctuations affect cell behavior requires the quantification of both behavior and protein numbers in the same cells. Here, we combine automated microscopy with in situ hydrogel polymerization to measure single-cell protein expression after tracking swimming behavior. We characterized the distribution of non-genetic phenotypic diversity in Escherichia coli motility, which affects single-cell exploration. By expressing fluorescently tagged chemotaxis proteins (CheR and CheB at different levels, we quantitatively mapped motile phenotype (tumble bias to protein numbers using thousands of single-cell measurements. Our results disagreed with established models until we incorporated the role of CheB in receptor deamidation and the slow fluctuations in receptor methylation. Beyond refining models, our central finding is that changes in numbers of CheR and CheB affect the population mean tumble bias and its variance independently. Therefore, it is possible to adjust the degree of phenotypic diversity of a population by adjusting the global level of expression of CheR and CheB while keeping their ratio constant, which, as shown in previous studies, confers functional robustness to the system. Since genetic control of protein expression is heritable, our results suggest that non-genetic diversity in motile behavior is selectable, supporting earlier hypotheses that such diversity confers a selective advantage.

  9. Complex regulatory network encompassing the Csr, c-di-GMP and motility systems of Salmonella Typhimurium.

    Science.gov (United States)

    Jonas, Kristina; Edwards, Adrianne N; Ahmad, Irfan; Romeo, Tony; Römling, Ute; Melefors, Ojar

    2010-02-01

    Bacterial survival depends on the ability to switch between sessile and motile lifestyles in response to changing environmental conditions. In many species, this switch is governed by (3'-5')-cyclic-diguanosine monophosphate (c-di-GMP), a signalling molecule, which is metabolized by proteins containing GGDEF and/or EAL domains. Salmonella Typhimurium contains 20 such proteins. Here, we show that the RNA-binding protein CsrA regulates the expression of eight genes encoding GGDEF, GGDEF-EAL and EAL domain proteins. CsrA bound directly to the mRNA leaders of five of these genes, suggesting that it may regulate these genes post-transcriptionally. The c-di-GMP-specific phosphodiesterase STM3611, which reciprocally controls flagella function and production of biofilm matrix components, was regulated by CsrA binding to the mRNA, but was also indirectly regulated by CsrA through the FlhDC/FliA flagella cascade and STM1344. STM1344 is an unconventional (c-di-GMP-inactive) EAL domain protein, recently identified as a negative regulator of flagella gene expression. Here, we demonstrate that CsrA directly downregulates expression of STM1344, which in turn regulates STM3611 through fliA and thus reciprocally controls motility and biofilm factors. Altogether, our data reveal that the concerted and complex regulation of several genes encoding GGDEF/EAL domain proteins allows CsrA to control the motility-sessility switch in S. Typhimurium at multiple levels.

  10. A cyclic GMP signalling module that regulates gliding motility in a malaria parasite.

    Directory of Open Access Journals (Sweden)

    Robert W Moon

    2009-09-01

    Full Text Available The ookinete is a motile stage in the malaria life cycle which forms in the mosquito blood meal from the zygote. Ookinetes use an acto-myosin motor to glide towards and penetrate the midgut wall to establish infection in the vector. The regulation of gliding motility is poorly understood. Through genetic interaction studies we here describe a signalling module that identifies guanosine 3', 5'-cyclic monophosphate (cGMP as an important second messenger regulating ookinete differentiation and motility. In ookinetes lacking the cyclic nucleotide degrading phosphodiesterase delta (PDEdelta, unregulated signalling through cGMP results in rounding up of the normally banana-shaped cells. This phenotype is suppressed in a double mutant additionally lacking guanylyl cyclase beta (GCbeta, showing that in ookinetes GCbeta is an important source for cGMP, and that PDEdelta is the relevant cGMP degrading enzyme. Inhibition of the cGMP-dependent protein kinase, PKG, blocks gliding, whereas enhanced signalling through cGMP restores normal gliding speed in a mutant lacking calcium dependent protein kinase 3, suggesting at least a partial overlap between calcium and cGMP dependent pathways. These data demonstrate an important function for signalling through cGMP, and most likely PKG, in dynamically regulating ookinete gliding during the transmission of malaria to the mosquito.

  11. Sympathetic and parasympathetic regulation of rectal motility in rats.

    Science.gov (United States)

    Ridolfi, Timothy J; Tong, Wei-Dong; Takahashi, Toku; Kosinski, Lauren; Ludwig, Kirk A

    2009-11-01

    The colon and rectum are regulated by the autonomic nervous system (ANS). Abnormalities of the ANS are associated with diseases of the colon and rectum while its modulation is a putative mechanism for sacral nerve stimulation. The purpose of this study is to establish a rat model elucidating the role of the efferent ANS on rectal motility. Rectal motility following transection or stimulation of parasympathetic pelvic nerves (PN) or sympathetic hypogastric nerves (HGN) was measured with rectal strain gauge transducers and quantified as a motility index (MI). Colonic transit was measured 24 hours after transection by calculating the geometric center (GC) of distribution of (51)Cr Transection of PN and HGN decreased MI to 518 +/- 185 g*s (p < 0.05) and increased MI to 5,029 +/- 1,954 g*s (p < 0.05), respectively, compared to sham (975 +/- 243 g*s). Sectioning of PN and HGN decreased transit with GC = 4.9 +/- 0.2 (p < 0.05) and increased transit with GC = 8.1 +/- 0.7 (p < 0.02), respectively, compared to sham (GC = 5.8 +/- 0.3). Stimulation of PN and HGN increased MI to 831 +/- 157% (p < 0.01) and decreased MI to 251 +/- 24% (p < 0.05), respectively. Rectal motility is significantly altered by sectioning or stimulating either HGN or PN. This model may be useful in studying how sacral nerve stimulation exerts its effects and provide insight into the maladies of colonic motility.

  12. Microscopic Analysis of Bacterial Motility at High Pressure

    Science.gov (United States)

    Nishiyama, Masayoshi; Sowa, Yoshiyuki

    2012-01-01

    The bacterial flagellar motor is a molecular machine that converts an ion flux to the rotation of a helical flagellar filament. Counterclockwise rotation of the filaments allows them to join in a bundle and propel the cell forward. Loss of motility can be caused by environmental factors such as temperature, pH, and solvation. Hydrostatic pressure is also a physical inhibitor of bacterial motility, but the detailed mechanism of this inhibition is still unknown. Here, we developed a high-pressure microscope that enables us to acquire high-resolution microscopic images, regardless of applied pressures. We also characterized the pressure dependence of the motility of swimming Escherichia coli cells and the rotation of single flagellar motors. The fraction and speed of swimming cells decreased with increased pressure. At 80 MPa, all cells stopped swimming and simply diffused in solution. After the release of pressure, most cells immediately recovered their initial motility. Direct observation of the motility of single flagellar motors revealed that at 80 MPa, the motors generate torque that should be sufficient to join rotating filaments in a bundle. The discrepancy in the behavior of free swimming cells and individual motors could be due to the applied pressure inhibiting the formation of rotating filament bundles that can propel the cell body in an aqueous environment. PMID:22768943

  13. Effects of multiple collections on spermatozoa quality of Persian sturgeon, Acipenser persicus: motility, density and seminal plasma composition.

    Science.gov (United States)

    Aramli, M S; Kalbassi, M R; Gharibi, M R

    2015-02-01

    In this study, we investigated the effects of multiple collections of sperm on the endangered Persian sturgeon, Acipenser persicus, in terms of a number of sperm functional parameters (percentage of motile spermatozoa, total time period of motility and sperm concentration) as well as on the ionic composition, protein concentration and osmolality of seminal plasma. Semen samples were collected from 12 induced male fish in three experimental groups that had been injected intramuscularly with LHRH-A2, at dosages of 5 μg/kg body weight, at a number of time regimes: at 12 h, 17 h and 24 h after spawning induction (1); at 24, 29 and 34 h after spawning induction (2); and at 36, 41 and 46 h after spawning induction (3). The percentage of motile spermatozoa and the period of sperm motility decreased significantly (p collections. The concentration of spermatozoa decreased after the third collection, but this decline was not significant. No significant effect of multiple collections on protein concentration and ionic content (with exception of the Cl(-) ion) of seminal plasma was observed. In all experimental groups, a moderate impact of sequential collection on the osmolality (p collections on spermatological characteristics in the Persian sturgeon. Our results confirm that sequential stripping after the third collections has a negative effect on a number of functional parameters associated with sperm. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  14. Correlation of Adiponectin mRNA Abundance and Its Receptors with Quantitative Parameters of Sperm Motility in Rams

    Directory of Open Access Journals (Sweden)

    Ali Kadivar

    2016-05-01

    Full Text Available Background: Adiponectin and its receptors (AdipoR1 and AdipoR2, known as adiponectin system, have some proven roles in the fat and glucose metabolisms. Several studies have shown that adiponectin can be considered as a candidate in linking metabolism to testicular function. In this regard, we evaluated the correlation between sperm mRNA abundance of adiponectin and its receptors, with sperm motility indices in the present study. Materials and Methods: In this completely randomized design study, semen samples from 6 adult rams were fractionated on a two layer discontinuous percoll gradient into high and low motile sperm cells, then quantitative parameters of sperm motility were determined by computer-assisted sperm analyzer (CASA. The mRNA abundance levels of Adiponectin, AdipoR1 and AdipoR2 were measured quantitatively using real-time reverse transcriptase polymerase chain reaction (qRT-PCR in the high and low motile groups. Results: Firstly, we showed that adiponectin and its receptors (AdipoR1 and AdipoR2 were transcriptionally expressed in the ram sperm cells. Using Pfaff based method qRTPCR, these levels of transcription were significantly higher in the high motile rather than low motile samples. This increase was 3.5, 3.6 and 2.5 fold change rate for Adiponectin, AdipoR1 and AdipoR2, respectively. Some of sperm motility indices [curvilinear velocity (VCL, straight-line velocity (VSL, average path velocity (VAP, linearity (LIN, wobble (WOB and straightness (STR] were also significantly correlated with Adiponectin and AdipoR1 relative expression. The correlation of AdipoR2 was also significant with the mentioned parameters, although this correlation was not comparable with adiponectin and AdipoR1. Conclusion: This study revealed the novel association of adiponectin system with sperm motility. The results of our study suggested that adiponectin is one of the possible factors which can be evaluated and studied in male infertility disorders.

  15. Wireless Cellular Mobile Communications

    OpenAIRE

    Zalud, V.

    2002-01-01

    In this article is briefly reviewed the history of wireless cellular mobile communications, examined the progress in current second generation (2G) cellular standards and discussed their migration to the third generation (3G). The European 2G cellular standard GSM and its evolution phases GPRS and EDGE are described somewhat in detail. The third generation standard UMTS taking up on GSM/GPRS core network and equipped with a new advanced access network on the basis of code division multiple ac...

  16. Changes in Swallowing Symptoms and Esophageal Motility After Thyroid Surgery

    DEFF Research Database (Denmark)

    Sorensen, Jesper Roed; Markoew, Simone; Døssing, Helle

    2018-01-01

    INTRODUCTION: Swallowing difficulties, the pathophysiology behind which is incompletely understood, have been reported in 47-83% of goiter patients referred for thyroidectomy. We aimed at examining the influence of thyroid surgery on swallowing symptoms and esophageal motility. METHODS: Thirty-th...... to esophageal motility disturbances. This information is essential when interpreting dysphagia in patients with nodular goiter, and when balancing patients' expectations to surgical goiter therapy. REGISTRATION NUMBER: NCT03100357 ( www.clinicaltrials.org ).......INTRODUCTION: Swallowing difficulties, the pathophysiology behind which is incompletely understood, have been reported in 47-83% of goiter patients referred for thyroidectomy. We aimed at examining the influence of thyroid surgery on swallowing symptoms and esophageal motility. METHODS: Thirty......-three patients with benign nodular goiter undergoing thyroid surgery were included. All completed high-resolution esophageal manometry examinations and the goiter symptom scale score, assessed by the thyroid-specific patient-reported outcome measure. The evaluations were performed before and 6 months after...

  17. Motility, Force Generation, and Energy Consumption of Unicellular Parasites.

    Science.gov (United States)

    Hochstetter, Axel; Pfohl, Thomas

    2016-07-01

    Motility is a key factor for pathogenicity of unicellular parasites, enabling them to infiltrate and evade host cells, and perform several of their life-cycle events. State-of-the-art methods of motility analysis rely on a combination of optical tweezers with high-resolution microscopy and microfluidics. With this technology, propulsion forces, energies, and power generation can be determined so as to shed light on the motion mechanisms, chemotactic behavior, and specific survival strategies of unicellular parasites. With these new tools in hand, we can elucidate the mechanisms of motility and force generation of unicellular parasites, and identify ways to manipulate and eventually inhibit them. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

    KAUST Repository

    Ziebert, F.; Swaminathan, S.; Aranson, I. S.

    2011-01-01

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

  19. Gastrointestinal Motility Disorders and Their Clinical Implications in Cirrhosis

    Directory of Open Access Journals (Sweden)

    Eleni Theocharidou

    2017-01-01

    Full Text Available Gastrointestinal motility is impaired in a substantial proportion of patients with cirrhosis. Cirrhosis-related autonomic neuropathy, increased nitric oxide production, and gut hormonal changes have been implicated. Oesophageal dysmotility has been associated with increased frequency of abnormal gastro-oesophageal reflux. Impaired gastric emptying and accommodation may result in early satiety and may have an impact on the nutritional status of these patients. Small intestinal dysmotility might be implicated in small intestinal bacterial overgrowth and increased bacterial translocation. The latter has been implicated in the pathophysiology of hepatic encephalopathy and spontaneous bacterial peritonitis. Enhanced colonic motility is usually associated with the use of lactulose. Pharmacological interventions aiming to alter gastrointestinal motility in cirrhosis could potentially have a beneficial effect reducing the risk of hepatic decompensation and improving prognosis.

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

    KAUST Repository

    Ziebert, F.

    2011-10-19

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

  1. Biomechanics of cellular solids.

    Science.gov (United States)

    Gibson, Lorna J

    2005-03-01

    Materials with a cellular structure are widespread in nature and include wood, cork, plant parenchyma and trabecular bone. Natural cellular materials are often mechanically efficient: the honeycomb-like microstructure of wood, for instance, gives it an exceptionally high performance index for resisting bending and buckling. Here we review the mechanics of a wide range of natural cellular materials and examine their role in lightweight natural sandwich structures (e.g. iris leaves) and natural tubular structures (e.g. plant stems or animal quills). We also describe two examples of engineered biomaterials with a cellular structure, designed to replace or regenerate tissue in the body.

  2. The effect of loss of O-antigen ligase on phagocytic susceptibility of motile and non-motile Pseudomonas aeruginosa.

    Science.gov (United States)

    Demirdjian, Sally; Schutz, Kristin; Wargo, Matthew J; Lam, Joseph S; Berwin, Brent

    2017-12-01

    The bacterial pathogen Pseudomonas aeruginosa undergoes adaptation and selection over the course of chronic respiratory tract infections which results in repeatedly-observed phenotypic changes that are proposed to enable its persistence. Two of the clinically significant P. aeruginosa phenotypic changes are loss of flagellar motility and modifications to LPS structure, including loss of O-antigen expression. The effect of loss of O-antigen, frequently described as conversion from smooth to rough LPS, and the combined effect of loss of motility and O-antigen on phagocytic susceptibility by immune cells remain unknown. To address this, we generated genetic deletion mutants of waaL, which encodes the O-antigen ligase responsible for linking O-antigen to lipid A-core oligosaccharide, in both motile and non-motile P. aeruginosa strains. With the use of these bacterial strains we provide the first demonstration that, despite a progressive selection for P. aeruginosa with rough LPS during chronic pulmonary infections, loss of the LPS O-antigen does not confer phagocytic resistance in vitro. However, use of the waaLmotABmotCD mutant revealed that loss of motility confers resistance to phagocytosis regardless of the smooth or rough LPS phenotype. These findings reveal how the O-antigen of P. aeruginosa can influence bacterial clearance during infection and expand our current knowledge about the impact of bacterial phenotypic changes during chronic infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Structural, molecular and cellular functions of MSH2 and MSH6 during DNA mismatch repair, damage signaling and other noncanonical activities

    Energy Technology Data Exchange (ETDEWEB)

    Edelbrock, Michael A., E-mail: Edelbrock@findlay.edu [The University of Findlay, 1000 North Main Street, Findlay, OH 45840 (United States); Kaliyaperumal, Saravanan, E-mail: Saravanan.Kaliyaperumal@hms.harvard.edu [Division of Comparative Medicine and Pathology, New England Primate Research Center, One Pine Hill Drive, Southborough, MA 01772 (United States); Williams, Kandace J., E-mail: Kandace.williams@utoledo.edu [University of Toledo College of Medicine and Life Sciences, Department of Biochemistry and Cancer Biology, 3000 Transverse Dr., Toledo, OH 43614 (United States)

    2013-03-15

    The field of DNA mismatch repair (MMR) has rapidly expanded after the discovery of the MutHLS repair system in bacteria. By the mid 1990s yeast and human homologues to bacterial MutL and MutS had been identified and their contribution to hereditary non-polyposis colorectal cancer (HNPCC; Lynch syndrome) was under intense investigation. The human MutS homologue 6 protein (hMSH6), was first reported in 1995 as a G:T binding partner (GTBP) of hMSH2, forming the hMutSα mismatch-binding complex. Signal transduction from each DNA-bound hMutSα complex is accomplished by the hMutLα heterodimer (hMLH1 and hPMS2). Molecular mechanisms and cellular regulation of individual MMR proteins are now areas of intensive research. This review will focus on molecular mechanisms associated with mismatch binding, as well as emerging evidence that MutSα, and in particular, MSH6, is a key protein in MMR-dependent DNA damage response and communication with other DNA repair pathways within the cell. MSH6 is unstable in the absence of MSH2, however it is the DNA lesion-binding partner of this heterodimer. MSH6, but not MSH2, has a conserved Phe-X-Glu motif that recognizes and binds several different DNA structural distortions, initiating different cellular responses. hMSH6 also contains the nuclear localization sequences required to shuttle hMutSα into the nucleus. For example, upon binding to O{sup 6}meG:T, MSH6 triggers a DNA damage response that involves altered phosphorylation within the N-terminal disordered domain of this unique protein. While many investigations have focused on MMR as a post-replication DNA repair mechanism, MMR proteins are expressed and active in all phases of the cell cycle. There is much more to be discovered about regulatory cellular roles that require the presence of MutSα and, in particular, MSH6.

  4. Structural, molecular and cellular functions of MSH2 and MSH6 during DNA mismatch repair, damage signaling and other noncanonical activities

    International Nuclear Information System (INIS)

    Edelbrock, Michael A.; Kaliyaperumal, Saravanan; Williams, Kandace J.

    2013-01-01

    The field of DNA mismatch repair (MMR) has rapidly expanded after the discovery of the MutHLS repair system in bacteria. By the mid 1990s yeast and human homologues to bacterial MutL and MutS had been identified and their contribution to hereditary non-polyposis colorectal cancer (HNPCC; Lynch syndrome) was under intense investigation. The human MutS homologue 6 protein (hMSH6), was first reported in 1995 as a G:T binding partner (GTBP) of hMSH2, forming the hMutSα mismatch-binding complex. Signal transduction from each DNA-bound hMutSα complex is accomplished by the hMutLα heterodimer (hMLH1 and hPMS2). Molecular mechanisms and cellular regulation of individual MMR proteins are now areas of intensive research. This review will focus on molecular mechanisms associated with mismatch binding, as well as emerging evidence that MutSα, and in particular, MSH6, is a key protein in MMR-dependent DNA damage response and communication with other DNA repair pathways within the cell. MSH6 is unstable in the absence of MSH2, however it is the DNA lesion-binding partner of this heterodimer. MSH6, but not MSH2, has a conserved Phe-X-Glu motif that recognizes and binds several different DNA structural distortions, initiating different cellular responses. hMSH6 also contains the nuclear localization sequences required to shuttle hMutSα into the nucleus. For example, upon binding to O 6 meG:T, MSH6 triggers a DNA damage response that involves altered phosphorylation within the N-terminal disordered domain of this unique protein. While many investigations have focused on MMR as a post-replication DNA repair mechanism, MMR proteins are expressed and active in all phases of the cell cycle. There is much more to be discovered about regulatory cellular roles that require the presence of MutSα and, in particular, MSH6

  5. Enhancement of mouse sperm motility by trophinin-binding peptide

    Directory of Open Access Journals (Sweden)

    Park Seong

    2012-11-01

    Full Text Available Abstract Background Trophinin is an intrinsic membrane protein that forms a complex in the cytoplasm with bystin and tastin, linking it microtubule-associated motor dynein (ATPase in some cell types. Previously, we found that human sperm tails contain trophinin, bystin and tastin proteins, and that trophinin-binding GWRQ (glycine, tryptophan, arginine, glutamine peptide enhanced motility of human sperm. Methods Immunohistochemistry was employed to determine trophinin protein in mouse spermatozoa from wild type mouse, by using spermatozoa from trophinin null mutant mice as a negative control. Multivalent 8-branched GWRQ (glycine, tryptophan, arginine, glutamine peptide or GWRQ-MAPS, was chemically synthesized, purified by HPLC and its structure was confirmed by MALDI-TOF mass spectrometry. Effect of GWRQ-MAPS on mouse spermatozoa from wild type and trophinin null mutant was assessed by a computer-assisted semen analyzer (CASA. Results Anti-trophinin antibody stained the principal (central piece of the tail of wild type mouse sperm, whereas the antibody showed no staining on trophinin null sperm. Phage particles displaying GWRQ bound to the principal piece of sperm tail from wild type but not trophinin null mice. GWRQ-MAPS enhanced motility of spermatozoa from wild type but not trophinin null mice. CASA showed that GWRQ-MAPS enhanced both progressive motility and rapid motility in wild type mouse sperm. Conclusions Present study established the expression of trophinin in the mouse sperm tail and trophinin-dependent effect of GWRQ-MAPS on sperm motility. GWRQ causes a significant increase in sperm motility.

  6. Cell motility and antibiotic tolerance of bacterial swarms

    Science.gov (United States)

    Zuo, Wenlong

    Many bacteria species can move across moist surfaces in a coordinated manner known as swarming. It is reported that swarm cells show higher tolerance to a wide variety of antibiotics than planktonic cells. We used the model bacterium E. coli to study how motility affects the antibiotic tolerance of swarm cells. Our results provide new insights for the control of pathogenic invasion via regulating cell motility. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail: zwlong@live.com.

  7. Basic features of slime mould motility

    Science.gov (United States)

    Shirakawa, Tomohiro

    2015-03-01

    The plasmodium of Physarum polycephalum is a unicellular and multi-nuclear giant amoeba that is formed by fusions of myriads of uninucleate microscopic amoebae at a point in the life cycle of the organism. The very large unicellular form of the plasmodium is very uncommon in nature; on the contrary, almost all of the other higher organisms have multi-cellular bodies. Therefore, the plasmodium has an exceptional property: although the plasmodium is a unicellular organism, the size of the amoeba is variable. The smallest plasmodium consists of the fusion of two amoebae, so the smallest size is twice that of a usual amoeba. There is no upper limit to the largest size of the plasmodium, in principle. There is a record of very large plasmodium of more than a few metres. A more interesting point is that despite the variety in the size, the plasmodium can move, feed and form complex structures and adapt itself to the environment in an intelligent manner...

  8. Linearizable cellular automata

    International Nuclear Information System (INIS)

    Nobe, Atsushi; Yura, Fumitaka

    2007-01-01

    The initial value problem for a class of reversible elementary cellular automata with periodic boundaries is reduced to an initial-boundary value problem for a class of linear systems on a finite commutative ring Z 2 . Moreover, a family of such linearizable cellular automata is given

  9. UNC-73/Trio RhoGEF-2 Activity Modulates Caenorhabditis elegans Motility Through Changes in Neurotransmitter Signaling Upstream of the GSA-1/Gαs Pathway

    Science.gov (United States)

    Hu, Shuang; Pawson, Tony; Steven, Robert M.

    2011-01-01

    Rho-family GTPases play regulatory roles in many fundamental cellular processes. Caenorhabditis elegans UNC-73 RhoGEF isoforms function in axon guidance, cell migration, muscle arm extension, phagocytosis, and neurotransmission by activating either Rac or Rho GTPase subfamilies. Multiple differentially expressed UNC-73 isoforms contain a Rac-specific RhoGEF-1 domain, a Rho-specific RhoGEF-2 domain, or both domains. The UNC-73E RhoGEF-2 isoform is activated by the G-protein subunit Gαq and is required for normal rates of locomotion; however, mechanisms of UNC-73 and Rho pathway regulation of locomotion are not clear. To better define UNC-73 function in the regulation of motility we used cell-specific and inducible promoters to examine the temporal and spatial requirements of UNC-73 RhoGEF-2 isoform function in mutant rescue experiments. We found that UNC-73E acts within peptidergic neurons of mature animals to regulate locomotion rate. Although unc-73 RhoGEF-2 mutants have grossly normal synaptic morphology and weak resistance to the acetylcholinesterase inhibitor aldicarb, they are significantly hypersensitive to the acetylcholine receptor agonist levamisole, indicating alterations in acetylcholine neurotransmitter signaling. Consistent with peptidergic neuron function, unc-73 RhoGEF-2 mutants exhibit a decreased level of neuropeptide release from motor neuron dense core vesicles (DCVs). The unc-73 locomotory phenotype is similar to those of rab-2 and unc-31, genes with distinct roles in the DCV-mediated secretory pathway. We observed that constitutively active Gαs pathway mutations, which compensate for DCV-mediated signaling defects, rescue unc-73 RhoGEF-2 and rab-2 lethargic movement phenotypes. Together, these data suggest UNC-73 RhoGEF-2 isoforms are required for proper neurotransmitter signaling and may function in the DCV-mediated neuromodulatory regulation of locomotion rate. PMID:21750262

  10. UNC-73/trio RhoGEF-2 activity modulates Caenorhabditis elegans motility through changes in neurotransmitter signaling upstream of the GSA-1/Galphas pathway.

    Science.gov (United States)

    Hu, Shuang; Pawson, Tony; Steven, Robert M

    2011-09-01

    Rho-family GTPases play regulatory roles in many fundamental cellular processes. Caenorhabditis elegans UNC-73 RhoGEF isoforms function in axon guidance, cell migration, muscle arm extension, phagocytosis, and neurotransmission by activating either Rac or Rho GTPase subfamilies. Multiple differentially expressed UNC-73 isoforms contain a Rac-specific RhoGEF-1 domain, a Rho-specific RhoGEF-2 domain, or both domains. The UNC-73E RhoGEF-2 isoform is activated by the G-protein subunit Gαq and is required for normal rates of locomotion; however, mechanisms of UNC-73 and Rho pathway regulation of locomotion are not clear. To better define UNC-73 function in the regulation of motility we used cell-specific and inducible promoters to examine the temporal and spatial requirements of UNC-73 RhoGEF-2 isoform function in mutant rescue experiments. We found that UNC-73E acts within peptidergic neurons of mature animals to regulate locomotion rate. Although unc-73 RhoGEF-2 mutants have grossly normal synaptic morphology and weak resistance to the acetylcholinesterase inhibitor aldicarb, they are significantly hypersensitive to the acetylcholine receptor agonist levamisole, indicating alterations in acetylcholine neurotransmitter signaling. Consistent with peptidergic neuron function, unc-73 RhoGEF-2 mutants exhibit a decreased level of neuropeptide release from motor neuron dense core vesicles (DCVs). The unc-73 locomotory phenotype is similar to those of rab-2 and unc-31, genes with distinct roles in the DCV-mediated secretory pathway. We observed that constitutively active Gαs pathway mutations, which compensate for DCV-mediated signaling defects, rescue unc-73 RhoGEF-2 and rab-2 lethargic movement phenotypes. Together, these data suggest UNC-73 RhoGEF-2 isoforms are required for proper neurotransmitter signaling and may function in the DCV-mediated neuromodulatory regulation of locomotion rate.

  11. Tyrosine phosphorylation of dihydrolipoamide dehydrogenase as a potential cadmium target and its inhibitory role in r