WorldWideScience

Sample records for susceptibility fac tors

  1. FAC: Flexible Atomic Code

    Science.gov (United States)

    Gu, Ming Feng

    2018-02-01

    FAC calculates various atomic radiative and collisional processes, including radiative transition rates, collisional excitation and ionization by electron impact, energy levels, photoionization, and autoionization, and their inverse processes radiative recombination and dielectronic capture. The package also includes a collisional radiative model to construct synthetic spectra for plasmas under different physical conditions.

  2. Fac

    African Journals Online (AJOL)

    USER

    2016-05-04

    May 4, 2016 ... of its definite benefit realize. In pro ect-based industry such as construction, KM is ... Key Words: Organizational performance, Knowledge management and Critical success factors. Introduction. Individuals and groups constantly ..... The Essence of. Multivariate Thinking: Basic. Themes and Methods: Basic.

  3. Microfluidics microFACS for Life Detection

    Science.gov (United States)

    Platt, Donald W.; Hoover, Richard B.

    2010-01-01

    A prototype micro-scale Fluorescent Activated Cell Sorter (microFACS) for life detection has been built and is undergoing testing. A functional miniature microfluidics instrument with the ability to remotely distinguish live or dead bacterial cells from abiotic particulates in ice or permafrost of icy bodies of the solar system would be of fundamental value to NASA. The use of molecular probes to obtain the bio-signature of living or dead cells could answer the most fundamental question of Astrobiology: Does life exist beyond Earth? The live-dead fluorescent stains to be used in the microFACS instrument function only with biological cell walls. The detection of the cell membranes of living or dead bacteria (unlike PAH's and many other Biomarkers) would provide convincing evidence of present or past life. This miniature device rapidly examine large numbers of particulates from a polar ice or permafrost sample and distinguish living from dead bacteria cells and biological cells from mineral grains and abiotic particulates and sort the cells and particulates based on a staining system. Any sample found to exhibit fluorescence consistent with living cells could then be used in conjunction with a chiral labeled release experiment or video microscopy system to seek addition evidence for cellular metabolism or motility. Results of preliminary testing and calibration of the microFACS prototype instrument system with pure cultures and enrichment assemblages of microbial extremophiles will be reported.

  4. Detection and transmission of extracellular fac-tor producing Streptococcus suis serotype 2 strains in pigs

    NARCIS (Netherlands)

    Swildens, B.

    2009-01-01

    DETECTION AND TRANSMISSION OF EXTRACELLULAR FACTOR PRODUCING STREPTOCOCCUS SUIS SEROTYPE 2 STRAINS IN PIGS INTRODUCTION Streptococcus suis (S.suis) has been implicated in the etiology of many diseases among which meningitis in pigs. The virulent extracellular factor-positive strains of S.suis

  5. Frontal affinity chromatography (FAC): theory and basic aspects.

    Science.gov (United States)

    Kasai, Ken-ichi

    2014-01-01

    Frontal affinity chromatography (FAC) is a versatile analytical tool for determining specific interactions between biomolecules and is particularly useful in the field of glycobiology. This article presents its basic aspects, merits, and theory.

  6. EquiFACS: The Equine Facial Action Coding System.

    Directory of Open Access Journals (Sweden)

    Jen Wathan

    Full Text Available Although previous studies of horses have investigated their facial expressions in specific contexts, e.g. pain, until now there has been no methodology available that documents all the possible facial movements of the horse and provides a way to record all potential facial configurations. This is essential for an objective description of horse facial expressions across a range of contexts that reflect different emotional states. Facial Action Coding Systems (FACS provide a systematic methodology of identifying and coding facial expressions on the basis of underlying facial musculature and muscle movement. FACS are anatomically based and document all possible facial movements rather than a configuration of movements associated with a particular situation. Consequently, FACS can be applied as a tool for a wide range of research questions. We developed FACS for the domestic horse (Equus caballus through anatomical investigation of the underlying musculature and subsequent analysis of naturally occurring behaviour captured on high quality video. Discrete facial movements were identified and described in terms of the underlying muscle contractions, in correspondence with previous FACS systems. The reliability of others to be able to learn this system (EquiFACS and consistently code behavioural sequences was high--and this included people with no previous experience of horses. A wide range of facial movements were identified, including many that are also seen in primates and other domestic animals (dogs and cats. EquiFACS provides a method that can now be used to document the facial movements associated with different social contexts and thus to address questions relevant to understanding social cognition and comparative psychology, as well as informing current veterinary and animal welfare practices.

  7. Data-plane Defenses against Routing Attacks on Tor

    Directory of Open Access Journals (Sweden)

    Tan Henry

    2016-10-01

    Full Text Available Tor is susceptible to traffic correlation attacks in which an adversary who observes flows entering and leaving the anonymity network can apply statistical techniques to correlate flows and de-anonymize their endpoints. While an adversary may not be naturally positioned to conduct such attacks, a recent study shows that the Internet’s control-plane can be manipulated to increase an adversary’s view of the network, and consequently, improve its ability to perform traffic correlation. This paper explores, in-depth, the effects of control-plane attacks on the security of the Tor network. Using accurate models of the live Tor network, we quantify Tor’s susceptibility to these attacks by measuring the fraction of the Tor network that is vulnerable and the advantage to the adversary of performing the attacks. We further propose defense mechanisms that protect Tor users from manipulations at the control-plane. Perhaps surprisingly, we show that by leveraging existing trust anchors in Tor, defenses deployed only in the data-plane are sufficient to detect most control-plane attacks. Our defenses do not assume the active participation of Internet Service Providers, and require only very small changes to Tor. We show that our defenses result in a more than tenfold decrease in the effectiveness of certain control-plane attacks.

  8. Ion acoustic instability of HPT particles, FAC density, anomalous ...

    Indian Academy of Sciences (India)

    The magnetic field perturbations interpretable as field aligned current (FAC) layers and the electrostatic turbulence possibly due to electrostatic ion acoustic instability driven by these currents are shown. The critical drift velocity of Hot Plasma Torus (HPT) electrons and the growth rate of ion acoustic wave as a function of ...

  9. Ion acoustic instability of HPT particles, FAC density, anomalous ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Ion acoustic instability of HPT particles, FAC density, anomalous resistivity and parallel electric field in the auroral region. C S Jayasree1, G Renuka1 and C Venugopal2. 1Department of Physics, University of Kerala, Kariavattom, Trivandrum 695 581, India. e-mail: drgrenuka@netscape.net. 2Department of Physics ...

  10. Complete mitochondrial genome of threatened mahseer Tor tor ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 95; Issue 4. Complete mitochondrial genome of threatened mahseer Tor tor (Hamilton 1822) and its phylogenetic relationship within Cyprinidae family. A. PAVAN-KUMAR SUDHANSHU RAMAN PRAKASH G. KORINGA NAMRATA PATEL TEJAS SHAH RAJEEV K. SINGH ...

  11. Analysis of Cognitive Fac tors Affecting the Investment Decisions of Financial Managers of the City of Baranquilla

    OpenAIRE

    Alcalá Villarreal, José Luis

    2014-01-01

    The majority of the Chief financial officers admit (Roa, 2010) that exists a huge gap between the learned on corporate finance in the different business schools and what they have had to put into practice as executives and the explanation we can be summarized it in three key concepts that are: bias, The Structure and the Heuristic one, which with his set allow to deal on better form the finance of the behavior. These concepts compose what in terms of Investigation is known as the psychology o...

  12. Evaluation of galectin binding by frontal affinity chromatography (FAC).

    Science.gov (United States)

    Iwaki, Jun; Hirabayashi, Jun

    2015-01-01

    Frontal affinity chromatography (FAC) is a simple and versatile procedure enabling quantitative determination of diverse biological interactions in terms of dissociation constants (K d), even though these interactions are relatively weak. The method is best applied to glycans and their binding proteins, with the analytical system operating on the basis of highly reproducible isocratic elution by liquid chromatography. Its application to galectins has been successfully developed to characterize their binding specificities in detail. As a result, their minimal requirements for recognition of disaccharides, i.e., β-galactosides, as well as characteristic features of individual galectins, have been elucidated. In this chapter, we describe standard procedures to determine the K d's for interactions between a series of standard glycans and various galectins.

  13. As facções cariocas em perspectiva comparativa

    Directory of Open Access Journals (Sweden)

    Benjamin Lessing

    2008-03-01

    Full Text Available Entre os especialistas em segurança pública, tornou-se lugar-comum a idéia de que a guerra do tráfico no Rio de Janeiro é totalmente única no Brasil. Porém, essa afirmação é imprecisa. Organizações de narcotráfico em muitos aspectos comparáveis às facções cariocas existem em outros contextos urbanos. O que as diferencia é menos a capacidade de estabelecer o monopólio local sobre o comércio de drogas do que a resiliência da sua estrutura interna e, portanto, a duração da sua existência e dominação. Durante uma pesquisa de campo em nove comunidades de periferia de três cidades, observei não apenas uma alta variação nos graus de concentração entre os mercados locais de drogas, mas também de variação com o tempo dentro da mesma comunidade. Desta perspectiva, a estabilidade do mercado de drogas altamente concentrado do Rio de Janeiro pode ser visto como um equilíbrio único, no qual as forças de fragmentação operantes em outras cidades são neutralizadas por características específicas das facções cariocas. O meu argumento é o de que tais características decorrem do domínio exercido pelas facções sobre o sistema penitenciário desde antes do início da sua expansão para o comércio de drogas.It has become a commonplace that Rio de Janeiro’s guerra do tráfico is entirely unique within Brazil. In fact, this is inaccurate. Drug trafficking organizations that in many respects resemble Rio’s facções do exist in other urban contexts. What differentiates them is less the ability to establish a local monopoly on the drug trade than the resilience of their internal structure, and consequently the duration of their existence and domination. During field research in nine peripheral communities in three cities, I observed not only high variation in the degree of concentration between local drug markets, but also variation over time within single communities. In this light, the stability of Rio’s highly

  14. Blend Shape Interpolation and FACS for Realistic Avatar

    Science.gov (United States)

    Alkawaz, Mohammed Hazim; Mohamad, Dzulkifli; Basori, Ahmad Hoirul; Saba, Tanzila

    2015-03-01

    The quest of developing realistic facial animation is ever-growing. The emergence of sophisticated algorithms, new graphical user interfaces, laser scans and advanced 3D tools imparted further impetus towards the rapid advancement of complex virtual human facial model. Face-to-face communication being the most natural way of human interaction, the facial animation systems became more attractive in the information technology era for sundry applications. The production of computer-animated movies using synthetic actors are still challenging issues. Proposed facial expression carries the signature of happiness, sadness, angry or cheerful, etc. The mood of a particular person in the midst of a large group can immediately be identified via very subtle changes in facial expressions. Facial expressions being very complex as well as important nonverbal communication channel are tricky to synthesize realistically using computer graphics. Computer synthesis of practical facial expressions must deal with the geometric representation of the human face and the control of the facial animation. We developed a new approach by integrating blend shape interpolation (BSI) and facial action coding system (FACS) to create a realistic and expressive computer facial animation design. The BSI is used to generate the natural face while the FACS is employed to reflect the exact facial muscle movements for four basic natural emotional expressions such as angry, happy, sad and fear with high fidelity. The results in perceiving the realistic facial expression for virtual human emotions based on facial skin color and texture may contribute towards the development of virtual reality and game environment of computer aided graphics animation systems.

  15. Effect of Cr content on the FAC of pipe material at 150 .deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Park, Tae Jun; Kim, Hong Pyo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-06-15

    Flow accelerated corrosion (FAC) of the carbon steel piping in nuclear power plants (NPPs) has been major issue in nuclear industry. During the FAC, a protective oxide layer on carbon steel dissolves into flowing water leading to a thinning of the oxide layer and accelerating corrosion of base material. As a result, severe failures may occur in the piping and equipment of NPPs. Effect of alloying elements on FAC of pipe materials was studied with rotating cylinder FAC test facility at 150 .deg. C and at flow velocity of 4m/s. The facility is equipped with on line monitoring of pH, conductivity, dissolved oxygen(DO) and temperature. Test solution was the demineralized water, and DO concentration was less than 1 ppb. Surface appearance of A 106 Gr. B which is used widely in secondary pipe in NPPs showed orange peel appearance, typical appearance of FAC. The materials with Cr content higher than 0.17wt.% showed pit. The pit is thought to early degradation mode of FAC. The corrosion product within the pit was enriched with Cr, Mo, Cu, Ni and S. But S was not detected in SA336 F22V with 2.25wt.% Cr. The enrichment of Cr and Mo seemed to be related with low, solubility of Cr and Mo compared to Fe. Measured FAC rate was compared with Ducreaux's relationship and showed slightly lower FAC rate than Ducreaux's relationship.

  16. A new FACS approach isolates hESC derived endoderm using transcription factors.

    Directory of Open Access Journals (Sweden)

    Yuqiong Pan

    2011-03-01

    Full Text Available We show that high quality microarray gene expression profiles can be obtained following FACS sorting of cells using combinations of transcription factors. We use this transcription factor FACS (tfFACS methodology to perform a genomic analysis of hESC-derived endodermal lineages marked by combinations of SOX17, GATA4, and CXCR4, and find that triple positive cells have a much stronger definitive endoderm signature than other combinations of these markers. Additionally, SOX17(+ GATA4(+ cells can be obtained at a much earlier stage of differentiation, prior to expression of CXCR4(+ cells, providing an important new tool to isolate this earlier definitive endoderm subtype. Overall, tfFACS represents an advancement in FACS technology which broadly crosses multiple disciplines, most notably in regenerative medicine to redefine cellular populations.

  17. Humanoid Robot Head Design Based on Uncanny Valley and FACS

    Directory of Open Access Journals (Sweden)

    Jizheng Yan

    2014-01-01

    Full Text Available Emotional robots are always the focus of artificial intelligence (AI, and intelligent control of robot facial expression is a hot research topic. This paper focuses on the design of humanoid robot head, which is divided into three steps to achieve. The first step is to solve the uncanny valley about humanoid robot, to find and avoid the relationship between human being and robot; the second step is to solve the association between human face and robot head; compared with human being and robots, we analyze the similarities and differences and explore the same basis and mechanisms between robot and human analyzing the Facial Action Coding System (FACS, which guides us to achieve humanoid expressions. On the basis of the previous two steps, the third step is to construct a robot head; through a series of experiments we test the robot head, which could show some humanoid expressions; through human-robot interaction, we find people are surprised by the robot head expression and feel happy.

  18. A Usability Evaluation of Tor Launcher

    Directory of Open Access Journals (Sweden)

    Lee Linda

    2017-07-01

    Full Text Available Although Tor has state-of-the art anticensorship measures, users in heavily censored environments will not be able to connect to Tor if they cannot configure their connections. We perform the first usability evaluation of Tor Launcher, the graphical user interface (GUI that Tor Browser uses to configure connections to Tor. Our study shows that 79% (363 of 458 of user attempts to connect to Tor in simulated censored environments failed. We found that users were often frustrated during the process and tried options at random. In this paper, we measure potential usability issues, discuss design constraints unique to Tor, and provide recommendations based on what we learned to help more users connect to Tor while reducing the time they take to do so. Tor Browser incorporated the changes proposed by this study.

  19. Individualized FAC on bottom tab subassemblies to minimize adhesive gap between emitter and optics

    Science.gov (United States)

    Sauer, Sebastian; Müller, Tobias; Haag, Sebastian; Beleke, Andreas; Zontar, Daniel; Baum, Christoph; Brecher, Christian

    2017-02-01

    High Power Diode Laser (HPDL) systems with short focal length fast-axis collimators (FAC) require submicron assembly precision. Conventional FAC-Lens assembly processes require adhesive gaps of 50 microns or more in order to compensate for component tolerances (e.g. deviation of back focal length) and previous assembly steps. In order to control volumetric shrinkage of fast-curing UV-adhesives shrinkage compensation is mandatory. The novel approach described in this paper aims to minimize the impact of volumetric shrinkage due to the adhesive gap between HPDL edge emitters and FAC-Lens. Firstly, the FAC is actively aligned to the edge emitter without adhesives or bottom tab. The relative position and orientation of FAC to emitter are measured and stored. Consecutively, an individual subassembly of FAC and bottom tab is assembled on Fraunhofer IPT's mounting station with a precision of +/-1 micron. Translational and lateral offsets can be compensated, so that a narrow and uniform glue gap for the consecutive bonding process of bottom tab to heatsink applies (Figure 4). Accordingly, FAC and bottom tab are mounted to the heatsink without major shrinkage compensation. Fraunhofer IPT's department assembly of optical systems and automation has made several publications regarding active alignment of FAC lenses [SPIE LASE 8241-12], volumetric shrinkage compensation [SPIE LASE 9730-28] and FAC on bottom tab assembly [SPIE LASE 9727-31] in automated production environments. The approach described in this paper combines these and is the logical continuation of that work towards higher quality of HPDLs.

  20. Complete mitochondrial genome of threatened mahseer Tor tor ...

    Indian Academy of Sciences (India)

    The mahseers (Tor, Neolissochilus and Naziritor) are an important group of fishes endemic to Asia with the conservation status of most species evaluated as threatened. Conservation plans to revive these declining wild populations are hindered by unstable ... important food and game fishes of India. It inhabits rivers.

  1. NYNJ_FAC: usSEABED FACies data for the New York-New Jersey Region

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The facies data layer (FAC) is a point coverage of known sediment samplings, inspections, and probings from the usSEABED data collection and integrated using the...

  2. ATL_FAC: usSEABED facies data for the entire U.S. Atlantic Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The facies data layer (_FAC.txt) is a point coverage of known sediment samplings, inspections, and probings from the usSEABED data collection and integrated using...

  3. Nearly monotonic problems: A key to effective FA/C distributed sensor interpretation?

    Energy Technology Data Exchange (ETDEWEB)

    Carver, N. [Southern Illinois Univ., Carbondale, IL (United States); Lesser, V.; Whitehair, R. [Univ. of Massachusetts, Amherst, MA (United States)

    1996-12-31

    The functionally-accurate, cooperative (FA/C) distributed problem-solving paradigm is one approach for organizing distributed problem solving among homogeneous, cooperating agents. A key assumption of the FA/C model has been that the agents` local solutions can substitute for the raw data in determining the global solutions. This is not the case in general, however. Does this mean that researchers` intuitions have been wrong and/or that FA/C problem solving is not likely to be effective? We suggest that some domains have a characteristic that can account for the success of exchanging mainly local solutions. We call such problems nearly monotonic. This concept is discussed in the context of FA/C-based distributed sensor interpretation.

  4. Frontal affinity chromatography with MS detection (FAC-MS) in drug discovery.

    Science.gov (United States)

    Slon-Usakiewicz, Jacek J; Ng, William; Dai, Jin-Rui; Pasternak, Andrew; Redden, Peter R

    2005-03-15

    The emergence of a relatively new technique resulting from a combination of frontal affinity chromatography coupled with MS detection (FAC-MS) has extended the capabilities of MS in drug discovery and development. Its application in a broad range of biological systems, together with its label-free operation, relatively high throughput, ability to rank ligands and determine Kd, makes FAC-MS a universal tool enabling convenient and efficient screening in the identification of new potential drug leads. Here we will highlight FAC-MS screening studies and discuss where it can be applied in evaluating multiple protein-binding sites, protein-protein interactions and inactive proteins, and also in determining selectivity.

  5. Crystallization and Structure Determination of Fac-Triammin-Aquo-Oxalato-Cobalt (III)-Nitrate Monohydrate

    OpenAIRE

    Hrib, Cristian; Blaurock, Steffen; Edelmann, Frank

    2014-01-01

    The title compound, fac-triammin-aquo-oxalato-cobalt(III)-nitrate monohydrate, fac-[Co(NH3)3(C2O4)(H2O)]NO3·H2O (2), was prepared according to an original synthetic protocol published exactly 100 years ago by Alfred Werner by dissolving the indigo-blue non-electrolyte complex mer-triammin-chloro-oxalato-cobalt(III), mer-[Co(NH3)3(C2O4)Cl] (1), in boiling half-concentrated nitric acid. Contrary to the literature, it did not crystallize directly from the reaction mixture, but crystallization ...

  6. LaSalle D. Leffall, M.D., FACS and Leadership in American Surgery.

    Science.gov (United States)

    Britt, L D

    2017-12-12

    The term, Festschrift, is defined as a volume of learned articles or essays by colleagues and admirers, serving as a tribute to a scholar. The recognition of LaSalle D. Leffall, Jr., M.D., F.A.C.S. adds credence to the merits of such a tribute. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. 48 CFR 301.603-72 - FAC-C and HHS SAC certification requirements.

    Science.gov (United States)

    2010-10-01

    ... thereunder are not required to re-take training courses, but shall follow FAC-C training requirements when considering additional or required core training, if needed. See 301.603-74 for information regarding..., including additional HHS-specific training requirements for certain types of acquisitions, are specified in...

  8. 7 CFR 1945.18 - United States Department of Agriculture (USDA) Food and Agriculture Council (FAC).

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true United States Department of Agriculture (USDA) Food and Agriculture Council (FAC). 1945.18 Section 1945.18 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE...

  9. TOR

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A tornado warning is issued by the local NWS Weather Forecast Office (WFO) when a tornado is indicated by the WSR-88D radar or sighted by spotters.

  10. Crystallization and Structure Determination of Fac-Triammin-Aquo-Oxalato-Cobalt (III-Nitrate Monohydrate

    Directory of Open Access Journals (Sweden)

    Cristian G. Hrib

    2014-11-01

    Full Text Available The title compound, fac-triammin-aquo-oxalato-cobalt(III-nitrate monohydrate, fac-[Co(NH33(C2O4(H2O]NO3·H2O (2, was prepared according to an original synthetic protocol published exactly 100 years ago by Alfred Werner by dissolving the indigo-blue non-electrolyte complex mer-triammin-chloro-oxalato-cobalt(III, mer-[Co(NH33(C2O4Cl] (1, in boiling half-concentrated nitric acid. Contrary to the literature, it did not crystallize directly from the reaction mixture, but crystallization could be induced by saturating the solution with NaClO4. The structure of 2 has monoclinic (P21/n symmetry. The crystal structure displays an extensive array of N–H···O and O–H···O hydrogen bonding.

  11. Automated multiple ligand screening by frontal affinity chromatography-mass spectrometry (FAC-MS).

    Science.gov (United States)

    Ng, William; Dai, Jin-Rui; Slon-Usakiewicz, Jacek J; Redden, Peter R; Pasternak, Andrew; Reid, Neil

    2007-03-01

    High-throughput screening (HTS) efforts to discover "hits" typically rely on the large-scale parallel screening of individual compounds with attempts to screen mixtures of compounds typically and, unfortunately, giving rise to false positives and false negatives due to the nature of the HTS readout (% inhibition/activation above a defined threshold) that makes deconvolution virtually intractable. Bioaffinity screening methods have emerged as an alternative or orthogonal method to classic HTS. One of these methods, frontal affinity chromatography coupled to mass spectrometry detection (FAC-MS), although still a relatively new technique, is turning out to be a viable screening tool. However, to push FAC-MS more to the forefront as a moderate primary HTS system (or a secondary screening assay), automation needs to be addressed. An automated FAC-MS system is described using 2 columns containing immobilized hERbeta, whereby while 1 column is being regenerated, the other is being used. The authors are extrapolating that in a continuous 24-h operation, the number of ligands screened could potentially approach 10,000. In addition, preliminary structure-activity relationship binding information (typically not seen in early primary HTS) can be obtained by observing the rank order of the library members in the various mixtures.

  12. A TorPath to TorCoin: Proof-of-Bandwidth Altcoins for Compensating Relays

    Science.gov (United States)

    2014-07-18

    TorCoin by checking the blockchain . Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of...of occasional colluding circuits, TorCoin also limits the number of coins each circuit can mine. This coin number is included in the blockchain , so it

  13. Effect of HNT on the Microstructure, Thermal and Mechanical Properties of Al/FACS-HNT Composites Produced by GPI

    Science.gov (United States)

    Siewiorek, A.; Malczyk, P.; Sobczak, N.; Sobczak, J. J.; Czulak, A.; Kozera, R.; Gude, M.; Boczkowska, A.; Homa, M.

    2016-08-01

    To develop an optimised manufacturing method of fly ash-reinforced metal matrix composites, the preliminary tests were performed on the cenospheres selected from fly ash (FACS) with halloysite nanotubes (HNTs) addition. The preform made out of FACS with and without the addition of HNT (with 5 and 10 wt.%) has been infiltrated by the pure aluminium (Al) via adapted gas pressure infiltration process. This paper reveals the influence of HNT addition on the microstructure (analysis was done by computed tomography and scanning electron microscopy combined with energy-dispersive x-ray spectroscopy), thermal properties (thermal expansion coefficient, thermal conductivity and specific heat) and the mechanical properties (hardness and compression test) of manufactured composites. The analysis of structure-property relationships for Al/FACS-HNT composites produced shows that the addition of 5 wt.% of HNT to FACS preform contributes to receiving of the best mechanical and structural properties of investigated composites.

  14. Image files of PCR data plotted on the FACS profiles - Plabrain DB | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data List Contact us Plab...earch . Data file File name: planaria_facs_profile.zip File URL: http://togodb.biosciencedbc.jp/togodb/view/plab...d License Update History of This Database Site Policy | Contact Us Image files of PCR data plotted on the FACS profiles - Plabrain DB | LSDB Archive ...

  15. The Fear-Avoidance Components Scale (FACS): Responsiveness to Functional Restoration Treatment in a Chronic Musculoskeletal Pain Disorder (CMPD) Population.

    Science.gov (United States)

    Neblett, Randy; Mayer, Tom G; Williams, Mark J; Asih, Sali; Cuesta-Vargas, Antonio I; Hartzell, Meredith M; Gatchel, Robert J

    2017-12-01

    To assess the clinical validity and factor structure of the Fear-Avoidance Components Scale (FACS), a new fear-avoidance measure. In this study, 426 chronic musculoskeletal pain disorder patients were admitted to a Functional Restoration Program (FRP). They were categorized into 5 FACS severity levels, from subclinical to extreme, at admission, and again at discharge. Associations with objective lifting performance and other patient-reported psychosocial measures were determined at admission and discharge, and objective work outcomes for this predominantly disabled cohort, were assessed 1 year later. Those patients in the severe and extreme FACS severity groups at admission were more likely to "drop out" of treatment than those in the lower severity groups (P=0.05). At both admission and discharge, the FACS severity groups were highly and inversely correlated with objective lifting performance and patient-reported fear-avoidance-related psychosocial variables, including kinesiophobia, pain intensity, depressive symptoms, perceived disability, perceived injustice, and insomnia (Ps<0.001). All variables showed improvement at FRP discharge. Patients in the extreme FACS severity group at discharge were less likely to return to, or retain, work 1 year later (P≤0.02). A factor analysis identified a 2-factor solution. Strong associations were found among FACS scores and other patient-reported psychosocial and objective lifting performance variables at both admission and discharge. High discharge-FACS scores were associated with worse work outcomes 1 year after discharge. The FACS seems to be a valid and clinically useful measure for predicting attendance, physical performance, distress, and relevant work outcomes in FRP treatment of chronic musculoskeletal pain disorder patients.

  16. Nutrient sensing and TOR signaling in yeast and mammals.

    Science.gov (United States)

    González, Asier; Hall, Michael N

    2017-02-15

    Coordinating cell growth with nutrient availability is critical for cell survival. The evolutionarily conserved TOR (target of rapamycin) controls cell growth in response to nutrients, in particular amino acids. As a central controller of cell growth, mTOR (mammalian TOR) is implicated in several disorders, including cancer, obesity, and diabetes. Here, we review how nutrient availability is sensed and transduced to TOR in budding yeast and mammals. A better understanding of how nutrient availability is transduced to TOR may allow novel strategies in the treatment for mTOR-related diseases. © 2017 The Authors.

  17. Fractura vertebral torácica en espondilitis anquilosante: importancia de la cuarta columna y consideraciones terapéuticas

    OpenAIRE

    Doménech, J.; Doménech, P.; Cabanes, F.

    2015-01-01

    Las fracturas por cizallamiento de la columna torácica con afectación de las tres columnas son altamente inestables y requieren fijación quirúrgica para evitar deterioro neurológico. Los pacientes con espondilitis anquilosante (EA) son susceptibles a este tipo de fracturas con traumatismos mínimos. Presentamos el caso de un varón de 72 años con EA que sufrió una fractura de la columna torácica por cizallamiento afectando a las tres columnas. La fractura paso desapercibida y el pac...

  18. Tor: The Second-Generation Onion Router

    Science.gov (United States)

    2004-01-01

    of which provides ses- sion keys and the address of the next server in the circuit. Tor as described herein, Tarzan, MorphMix, Cebolla [9], and...December 2000. [9] Z. Brown. Cebolla : Pragmatic IP Anonymity. In Ottawa Linux Symposium, June 2002. [10] D. Chaum. Untraceable electronic mail, return

  19. The application of silicalite-1/fly ash cenosphere (S/FAC) zeolite composite for the adsorption of methyl tert-butyl ether (MTBE).

    Science.gov (United States)

    Lu, Jia; Xu, Fang; Wang, Deju; Huang, Jue; Cai, Weimin

    2009-06-15

    Silicalite-1/fly ash cenosphere (S/FAC) zeolite composite has been applied for batch adsorption of methyl tert-butyl ether (MTBE) from water systems. Here the key experimental conditions, including the ratio of initial MTBE concentration to the amount weight of S/FAC, adsorption time and temperature, have been discussed in detail. The results show that approximately 93-95% MTBE could be adsorbed with initial concentration of MTBE solution 1000 microg l(-1). The column flow-through experiments also prove the high capacity of S/FAC composite for MTBE removal. The distinct advantages of S/FAC zeolite composite as adsorbent lie in (1) enhanced adsorption rate and capacity based on hierarchical micro and meso/macroporosity of S/FAC; (2) more easily operation and recycling process by assembly of nano-sized silicalite-1 zeolite on FAC support.

  20. Lysis matters: red cell lysis with FACS Lyse affects the flow cytometric enumeration of circulating leukemic blasts.

    Science.gov (United States)

    Einwallner, Elisa; Subasic, Almira; Strasser, Andrea; Augustin, Dorothea; Thalhammer, Renate; Steiner, Irene; Schwarzinger, Ilse

    2013-04-30

    The whole blood lysis method has become a standard procedure to remove red cells prior to immunophenotypic analysis of leukocytes. In the present study we investigated the influence of four different lysis protocols on the flow cytometric recovery of leukemic blasts. 32 blast cells containing blood samples were stained with anti-CD45 and anti-CD34 monoclonal antibody combinations. Red cell lysis was performed with FACS Lysing Solution and BD PharmLyse™ (Becton Dickinson and Company BD Biosciences, San Jose, CA; n=32) as well as Optilyse C and IOTest 3 (Immunotech SAS, Marseille; n=15 out of 32). Flow cytometric enumeration of blasts was performed on a FACS-Canto flow cytometer. The percentage of blasts after treatment with FACS Lyse was significantly smaller than after PharmLyse™ (pred cell lysis protocols for the application of flow cytometry in hematological neoplasms. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. PeerFlow: Secure Load Balancing in Tor

    Directory of Open Access Journals (Sweden)

    Johnson Aaron

    2017-04-01

    Full Text Available We present PeerFlow, a system to securely load balance client traffic in Tor. Security in Tor requires that no adversary handle too much traffic. However, Tor relays are run by volunteers who cannot be trusted to report the relay bandwidths, which Tor clients use for load balancing. We show that existing methods to determine the bandwidths of Tor relays allow an adversary with little bandwidth to attack large amounts of client traffic. These methods include Tor’s current bandwidth-scanning system, TorFlow, and the peer-measurement system EigenSpeed. We present an improved design called PeerFlow that uses a peer-measurement process both to limit an adversary’s ability to increase his measured bandwidth and to improve accuracy. We show our system to be secure, fast, and efficient. We implement PeerFlow in Tor and demonstrate its speed and accuracy in large-scale network simulations.

  2. Selfrando: Securing the Tor Browser against De-anonymization Exploits

    Directory of Open Access Journals (Sweden)

    Conti Mauro

    2016-10-01

    Full Text Available Tor is a well-known anonymous communication system used by millions of users, including journalists and civil rights activists all over the world. The Tor Browser gives non-technical users an easy way to access the Tor Network. However, many government organizations are actively trying to compromise Tor not only in regions with repressive regimes but also in the free world, as the recent FBI incidents clearly demonstrate. Exploiting software vulnerabilities in general, and browser vulnerabilities in particular, constitutes a clear and present threat to the Tor software. The Tor Browser shares a large part of its attack surface with the Firefox browser. Therefore, Firefox vulnerabilities (even patched ones are highly valuable to attackers trying to monitor users of the Tor Browser.

  3. FACS-based single-cell PCR data - Plabrain DB | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data List Contact us Plab... the FACS profiles . Data file File name: planaria_fbsc_pcr.zip File URL: ftp://ftp.biosciencedbc.jp/archive/plab...rain-db/LATEST/planaria_fbsc_pcr.zip File size: 1KB Simple search URL http://togodb.biosciencedbc.jp/togodb/view/plab...Update History of This Database Site Policy | Contact Us FACS-based single-cell PCR data - Plabrain DB | LSDB Archive ...

  4. PAC_FAC: Seabed facies data (combined components) for the continental margin of the U.S. Pacific Coast (California, Oregon, Washington) from usSEABED (pac_fac.txt)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The facies data layer (PAC_FAC.txt) is one of five point coverages of known sediment samples, inspections, and probes from the usSEABED data collection for the U.S....

  5. mTOR Activation by PI3K/Akt and ERK Signaling in Short ELF-EMF Exposed Human Keratinocytes.

    Directory of Open Access Journals (Sweden)

    Antonia Patruno

    Full Text Available Several reports suggest that ELF-EMF exposures interact with biological processes including promotion of cell proliferation. However, the molecular mechanisms by which ELF-EMF controls cell growth are not completely understood. The present study aimed to investigate the effect of ELF-EMF on keratinocytes proliferation and molecular mechanisms involved. Effect of ELF-EMF (50 Hz, 1 mT on HaCaT cell cycle and cells growth and viability was monitored by FACS analysis and BrdU assay. Gene expression profile by microarray and qRT-PCR validation was performed in HaCaT cells exposed or not to ELF-EMF. mTOR, Akt and MAPKs expressions were evaluated by Western blot analysis. In HaCaT cells, short ELF-EMF exposure modulates distinct patterns of gene expression involved in cell proliferation and in the cell cycle. mTOR activation resulted the main molecular target of ELF-EMF on HaCaT cells. Our data showed the increase of the canonical pathway of mTOR regulation (PI3K/Akt and activation of ERK signaling pathways. Our results indicate that ELF-EMF selectively modulated the expression of multiple genes related to pivotal biological processes and functions that play a key role in physio-pathological mechanisms such as wound healing.

  6. mTOR Activation by PI3K/Akt and ERK Signaling in Short ELF-EMF Exposed Human Keratinocytes

    Science.gov (United States)

    Patruno, Antonia; Pesce, Mirko; Grilli, Alfredo; Speranza, Lorenza; Franceschelli, Sara; De Lutiis, Maria Anna; Vianale, Giovina; Costantini, Erica; Amerio, Paolo; Muraro, Raffaella; Felaco, Mario; Reale, Marcella

    2015-01-01

    Several reports suggest that ELF-EMF exposures interact with biological processes including promotion of cell proliferation. However, the molecular mechanisms by which ELF-EMF controls cell growth are not completely understood. The present study aimed to investigate the effect of ELF-EMF on keratinocytes proliferation and molecular mechanisms involved. Effect of ELF-EMF (50 Hz, 1 mT) on HaCaT cell cycle and cells growth and viability was monitored by FACS analysis and BrdU assay. Gene expression profile by microarray and qRT-PCR validation was performed in HaCaT cells exposed or not to ELF-EMF. mTOR, Akt and MAPKs expressions were evaluated by Western blot analysis. In HaCaT cells, short ELF-EMF exposure modulates distinct patterns of gene expression involved in cell proliferation and in the cell cycle. mTOR activation resulted the main molecular target of ELF-EMF on HaCaT cells. Our data showed the increase of the canonical pathway of mTOR regulation (PI3K/Akt) and activation of ERK signaling pathways. Our results indicate that ELF-EMF selectively modulated the expression of multiple genes related to pivotal biological processes and functions that play a key role in physio-pathological mechanisms such as wound healing. PMID:26431550

  7. mTOR Activation by PI3K/Akt and ERK Signaling in Short ELF-EMF Exposed Human Keratinocytes.

    Science.gov (United States)

    Patruno, Antonia; Pesce, Mirko; Grilli, Alfredo; Speranza, Lorenza; Franceschelli, Sara; De Lutiis, Maria Anna; Vianale, Giovina; Costantini, Erica; Amerio, Paolo; Muraro, Raffaella; Felaco, Mario; Reale, Marcella

    2015-01-01

    Several reports suggest that ELF-EMF exposures interact with biological processes including promotion of cell proliferation. However, the molecular mechanisms by which ELF-EMF controls cell growth are not completely understood. The present study aimed to investigate the effect of ELF-EMF on keratinocytes proliferation and molecular mechanisms involved. Effect of ELF-EMF (50 Hz, 1 mT) on HaCaT cell cycle and cells growth and viability was monitored by FACS analysis and BrdU assay. Gene expression profile by microarray and qRT-PCR validation was performed in HaCaT cells exposed or not to ELF-EMF. mTOR, Akt and MAPKs expressions were evaluated by Western blot analysis. In HaCaT cells, short ELF-EMF exposure modulates distinct patterns of gene expression involved in cell proliferation and in the cell cycle. mTOR activation resulted the main molecular target of ELF-EMF on HaCaT cells. Our data showed the increase of the canonical pathway of mTOR regulation (PI3K/Akt) and activation of ERK signaling pathways. Our results indicate that ELF-EMF selectively modulated the expression of multiple genes related to pivotal biological processes and functions that play a key role in physio-pathological mechanisms such as wound healing.

  8. Regularity of Tor for weakly stable ideals

    Directory of Open Access Journals (Sweden)

    Katie Ansaldi

    2015-05-01

    Full Text Available It is proved that if I and J are weakly stable ideals in a polynomial ring R = k[x_1, . . ., x_n], with k a field, then the regularity of Tor^R_i (R/I, R/J has the expected upper bound. We also give a bound for the regularity of Ext^i_R (R/I, R for I a weakly stable ideal.

  9. CHOLERA EL-TOR EN IRAN

    Directory of Open Access Journals (Sweden)

    M. Ghodssi

    1969-01-01

    Full Text Available The bacteriological analysis shows that we have been confronted with the ELTor type, and only that type, until the end of the epidemic.The clinical study presents the symptoms of the real cholera with all its grievous consequences.The epidemiological supertnisicn stales that the El..Tor cholera is not agressiveat all in town areas whereas it presents its usual aspect in country areas, because of a lack of hygiene. there.That disease can be completely cured if the balance between the electrolytesis quickly restored.The disease was all the more dreadful since it came as a surprise and spread from one province to the other.L'examen bacteriologique montrc qu'il s'agit du type EI_ Tor et uniquement du meme type jusqu'a la fin de l'epldemie.La surveillance epidemiologique constate que Ie cholera EI_Tor n'cst nullement agressif dans Ie milieu urbain; mais qu'H revet l'aspect classique dans les milieuxruraux, depourvus d'hyglene.La maludic est totalement guerissablc a condition que l'equilibre des electrolytes so it rapidement retabli. L'evenement a tHe maladie se repandit d'une12

  10. Synthesis of novel CeO2-BiVO4/FAC composites with enhanced visible-light photocatalytic properties.

    Science.gov (United States)

    Zhang, Jin; Wang, Bing; Li, Chuang; Cui, Hao; Zhai, Jianping; Li, Qin

    2014-09-01

    To utilize visible light more effectively in photocatalytic reactions, a fly ash cenosphere (FAC)-supported CeO2-BiVO4 (CeO2-BiVO4/FAC) composite photocatalyst was prepared by modified metalorganic decomposition and impregnation methods. The physical and photophysical properties of the composite have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), and UV-Visible diffuse reflectance spectra. The XRD patterns exhibited characteristic diffraction peaks of both BiVO4 and CeO2 crystalline phases. The XPS results showed that Ce was present as both Ce(4+) and Ce(3+) oxidation states in CeO2 and dispersed on the surface of BiVO4 to constitute a p-n heterojunction composite. The absorption threshold of the CeO2-BiVO4/FAC composite shifted to a longer wavelength in the UV-Vis absorption spectrum compared to the pure CeO2 and pure BiVO4. The composites exhibited enhanced photocatalytic activity for Methylene Blue (MB) degradation under visible light irradiation. It was found that the 7.5wt.% CeO2-BiVO4/FAC composite showed the highest photocatalytic activity for MB dye wastewater treatment. Copyright © 2014. Published by Elsevier B.V.

  11. Community shifts of actively growing lake bacteria after N-acetyl-glucosamine addition: improving the BrdU-FACS method.

    Science.gov (United States)

    Tada, Yuya; Grossart, Hans-Peter

    2014-02-01

    In aquatic environments, community dynamics of bacteria, especially actively growing bacteria (AGB), are tightly linked with dissolved organic matter (DOM) quantity and quality. We analyzed the community dynamics of DNA-synthesizing and accordingly AGB by linking an improved bromodeoxyuridine immunocytochemistry approach with fluorescence-activated cell sorting (BrdU-FACS). FACS-sorted cells of even oligotrophic ecosystems in winter were characterized by 16S rRNA gene analysis. In incubation experiments, we examined community shifts of AGB in response to the addition of N-acetyl-glucosamine (NAG), one of the most abundant aminosugars in aquatic systems. Our improved BrdU-FACS analysis revealed that AGB winter communities of oligotrophic Lake Stechlin (northeastern Germany) substantially differ from those of total bacteria and consist of Alpha-, Beta-, Gamma-, Deltaproteobacteria, Actinobacteria, Candidatus OP10 and Chloroflexi. AGB populations with different BrdU-fluorescence intensities and cell sizes represented different phylotypes suggesting that single-cell growth potential varies at the taxon level. NAG incubation experiments demonstrated that a variety of widespread taxa related to Alpha-, Beta-, Gammaproteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, Planctomycetes, Spirochaetes, Verrucomicrobia and Chloroflexi actively grow in the presence of NAG. The BrdU-FACS approach enables detailed phylogenetic studies of AGB and, thus, to identify those phylotypes which are potential key players in aquatic DOM cycling.

  12. MaqFACS (Macaque Facial Action Coding System can be used to document facial movements in Barbary macaques (Macaca sylvanus

    Directory of Open Access Journals (Sweden)

    Églantine Julle-Danière

    2015-09-01

    Full Text Available Human and non-human primates exhibit facial movements or displays to communicate with one another. The evolution of form and function of those displays could be better understood through multispecies comparisons. Anatomically based coding systems (Facial Action Coding Systems: FACS are developed to enable such comparisons because they are standardized and systematic and aid identification of homologous expressions underpinned by similar muscle contractions. To date, FACS has been developed for humans, and subsequently modified for chimpanzees, rhesus macaques, orangutans, hylobatids, dogs, and cats. Here, we wanted to test whether the MaqFACS system developed in rhesus macaques (Macaca mulatta could be used to code facial movements in Barbary macaques (M. sylvanus, a species phylogenetically close to the rhesus macaques. The findings show that the facial movement capacity of Barbary macaques can be reliably coded using the MaqFACS. We found differences in use and form of some movements, most likely due to specializations in the communicative repertoire of each species, rather than morphological differences.

  13. Excited-state dynamics in fac-[Re(CO)3(Me4phen)(L)]+.

    Science.gov (United States)

    Patrocinio, Antonio Otavio T; Brennaman, M Kyle; Meyer, Thomas J; Murakami Iha, Neyde Y

    2010-11-25

    Excited-state dynamics in fac-[Re(CO)(3)(Me(4)phen)(cis-L)](+) (Me(4)phen = 3,4,7,8-tetramethyl-1,10-phenanthroline, L = 4-styrylpyridine (stpy) or 1,2-bis(4-pyridyl)ethylene (bpe)) were investigated by steady-state and time-resolved techniques. A complex equilibrium among three closely lying excited states, (3)IL(cis-L), (3)MLCT(Re→Me(4)phen), and (3)IL(Me(4)phen), has been established. Under UV irradiation, cis-to-trans isomerization of coordinated cis-L is observed with a quantum yield of 0.15 in acetonitrile solutions. This photoreaction competes with radiative decay from (3)MLCT(Re→Me(4)phen) and (3)IL(Me(4)phen) excited states, leading to a decrease in the emission quantum yield relative to the nonisomerizable complex fac-[Re(CO)(3)(Me(4)phen)(bpa)](+) (bpa = 1,2-bis(4-pyridyl)ethane). From temperature-dependent time-resolved emission measurements in solution and in poly(methyl methacrylate) (PMMA) films, energy barriers (ΔE(a)) for interconversion between (3)MLCT(Re→Me(4)phen) and (3)IL(Me(4)phen) emitting states were determined. For L = cis-stpy, ΔE(a) = 11 (920 cm(-1)) and 15 kJ mol(-1) (1254 cm(-1)) in 5:4 propionitrile/butyronitrile and PMMA, respectively. For L = cis-bpe, ΔE(a) = 13 kJ mol(-1) (1087 cm(-1)) in 5:4 propionitrile/butyronitrile. These energy barriers are sufficient to decrease the rate constant for internal conversion from higher-lying (3)IL(Me(4)phen) state to (3)MLCT(Re→Me(4)phen), k(i) ≅ 10(6) s(-1). The decrease in rate allows for the observation of intraligand phosphorescence, even in fluid medium at room temperature. Our results provide additional insight into the role of energy gap and excited-state dynamics on the photochemical and photophysical properties of Re(I) polypyridyl complexes.

  14. Users Get Routed: Traffic Correlation on Tor by Realistic Adversaries

    Science.gov (United States)

    2013-11-01

    the Tor network, simulate the user be- havior, and simulate the resulting Tor client software actions. We evaluate the user anonymity of these...client software for creating exit circuits, taking into account features significant to path selection, such as: bandwidth weighting; relay hibernation...Congestion-Aware Tor (CAT) by Wang et al. [43]. The main idea in CAT is that clients create a local view of circuit con- gestion through opportunistic and

  15. FACS-Assisted CRISPR-Cas9 Genome Editing Facilitates Parkinson's Disease Modeling

    Directory of Open Access Journals (Sweden)

    Jonathan Arias-Fuenzalida

    2017-11-01

    Full Text Available Genome editing and human induced pluripotent stem cells hold great promise for the development of isogenic disease models and the correction of disease-associated mutations for isogenic tissue therapy. CRISPR-Cas9 has emerged as a versatile and simple tool for engineering human cells for such purposes. However, the current protocols to derive genome-edited lines require the screening of a great number of clones to obtain one free of random integration or on-locus non-homologous end joining (NHEJ-containing alleles. Here, we describe an efficient method to derive biallelic genome-edited populations by the use of fluorescent markers. We call this technique FACS-assisted CRISPR-Cas9 editing (FACE. FACE allows the derivation of correctly edited polyclones carrying a positive selection fluorescent module and the exclusion of non-edited, random integrations and on-target allele NHEJ-containing cells. We derived a set of isogenic lines containing Parkinson's-disease-associated mutations in α-synuclein and present their comparative phenotypes.

  16. Engineering a promiscuous pyrrolysyl-tRNA synthetase by a high throughput FACS screen

    KAUST Repository

    Hohl, Adrian

    2017-12-06

    The Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNAPyl are used to facilitate the incorporation of non-canonical amino acids (ncAAs) into the genetic code of bacterial and eukaryotic cells by orthogonally reassigning the amber codon. Currently, the incorporation of new ncAAs requires a cumbersome engineering process composed of several positive and negative selection rounds to select the appropriate PylRS/tRNAPyl pair. Our fast and sensitive engineering approach required only a single FACS selection round to identify 110 orthogonal PylRS variants for the aminoacylation of 20 ncAAs. Pocket-substrate relationship from these variants led to the design of a highly promiscuous PylRS (HpRS), which catalyzed the aminoacylation of 31 structurally diverse lysine derivatives bearing clickable, fluorinated, fluorescent, and biotinylated entities. The high speed and sensitivity of our approach provides a competitive alternative to existing screening methodologies, and delivers insights into the complex PylRS-substrate interactions to facilitate the generation of additional promiscuous variants.

  17. Computed radiography plus rhythm software platform for FAC inspection in nuclear secondary circuit

    Energy Technology Data Exchange (ETDEWEB)

    Koetz, A.; Delannoy, L. [GE Sensing and Inspection Technologies, Skaneateles (United States); Knook, T. [EDF DTG, Grenoble (France)

    2011-07-01

    This paper will cover determining and ensuring proper follow up of Flow Accelerated Corrosion (FAC) in secondary circuit of Nuclear Power Plant using digital radiography. What are the relevant parameters on the pipes and weld wall thickness reading. How precise and reliable are the data and how best to record and archive. One challenge always faced with inspections is how to share the data and gain expert opinion when the expert is on-site; with digital inspection data and the use of software tools this challenge can be overcome. As you begin to collect all the inspection data the true 'power of the data' can be unfolded. Archiving of digital inspection data provides the foundation of asset management, allowing you to look at trends over time throughout inspection results done in one plant or multiple locations around the world. This document describes the process and results of tests performed through digital radiographic technic for the detection and sizing of thickness losses in weld roots areas. The tests were performed according to a pre-established program including a phase of testing on standard blocks and tubes and a phase of testing on components with real defects. (authors)

  18. fac-[N,N′-Bis(3-chloro-2-fluorobenzylideneethylenediamine]bromidotricarbonylrhenium(I

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2009-02-01

    Full Text Available In the title compound, [ReBr(C16H12Cl2F2N2(CO3], the Re atom is in a slightly distorted octahedral coordination environment with the three carbonyl ligands having a fac configuration. The diimine ligand is equatorial and is bonded to the Re centre in an N,N′-bidentate chelating fashion, with a bite angle of 77.7 (2°. The dihedral angle between the two benzene rings is 88.7 (6°. In the crystal structure, there are F...O [2.856 (9 Å], Cl...C [3.150 (8 Å] and O...C [2.984 (10 Å] contacts which are shorter than the sum of the van der Waals radii for these atoms. In addition, symmetry-related molecules are linked via intermolecular C—H...O, C—H...Br and the F...O interactions into one-dimensional chains extending along the a axis. The crystal structure is further stabilized by intermolecular π–π interactions [centroid–centroid distance = 3.571 (5 Å].

  19. Macht auf das Tor! - Opens the gate!

    Directory of Open Access Journals (Sweden)

    Claudemir de Quadros

    2011-09-01

    Full Text Available Macht auf das Tor! (Abra o portão foi publicado, possivelmente, na primeira metade do século 20. Editado por Max Dirkschneider, Raimund Heuler e Felix Oberborbeck, apresenta músicas, rimas, piadas, jogos e canções.A edição apresentada nesse espaço é de um livro que pertence à família de Carolina Drebes, estudante do curso de Pedagogia do Centro Universitário Franciscano, Santa Maria/RS.

  20. mTOR hyperactivity mediates the detrimental effects of a high sucrose diet on Alzheimer’s disease pathology

    Science.gov (United States)

    Orr, Miranda E.; Salinas, Angelica; Buffenstein, Rochelle; Oddo, Salvatore

    2014-01-01

    High sugar consumption and diabetes increase the risk of developing Alzheimer’s disease (AD) by unknown mechanisms. Using an animal model of AD, here we show that high sucrose intake induces obesity with changes in central and peripheral insulin signaling. These pre-diabetic changes are associated with an increase in Aβ production and deposition. Moreover, high sucrose ingestion exacerbates tau phosphorylation by increasing Cdk5 activity. Mechanistically, the sucrose-mediated increase in AD-like pathology is due to hyperactive mTOR, a key nutrient sensor important in regulating energy homeostasis. Specifically, we show that rapamycin, an mTOR inhibitor, prevents the detrimental effects of sucrose in the brain without altering changes in peripheral insulin resistance. Overall, our data suggest that high sucrose intake and dysregulated insulin signaling, which are known to contribute to the occurrence of diabetes, increase the risk of developing AD by upregulating mTOR signaling. Therefore, early interventions to modulate mTOR activity in individuals at high risk of developing diabetes may decrease their AD susceptibility. PMID:24411482

  1. Application of frontal affinity chromatography with mass spectrometry (FAC-MS) for stereospecific ligand-macromolecule interaction, detection and screening.

    Science.gov (United States)

    Slon-Usakiewicz, Jacek J; Redden, Peter

    2009-01-01

    Using frontal affinity chromatography coupled to mass spectrometry (FAC-MS) we have established a general stereoselective detection and screening method of intact racemates which can generate binding affinity information about the individual enantiomers that is also applicable to other ligand isomeric mixtures. FAC-MS has been shown to be a versatile technology utilizing direct binding in screening assays and extending its application toward chiral drug development, especially in the early discovery stages as well as its utility in secondary Structure-activity relationship (SAR) studies allow this platform to make a significant step toward facilitating the demand for pure enantiomeric drugs. Using renin, which is as an important drug target, we show that for detection and screening purposes there is no need to first use timely and costly methods of separating racemates in order to get precise information about the binding affinities of the composite enantiomers.

  2. Identifying the 630 nm auroral arc emission height: A comparison of the triangulation, FAC profile, and electron density methods

    Science.gov (United States)

    Megan Gillies, D.; Knudsen, D.; Donovan, E.; Jackel, B.; Gillies, R.; Spanswick, E.

    2017-08-01

    We present a comprehensive survey of 630 nm (red-line) emission discrete auroral arcs using the newly deployed Redline Emission Geospace Observatory. In this study we discuss the need for observations of 630 nm aurora and issues with the large-altitude range of the red-line aurora. We compare field-aligned currents (FACs) measured by the Swarm constellation of satellites with the location of 10 red-line (630 nm) auroral arcs observed by all-sky imagers (ASIs) and find that a characteristic emission height of 200 km applied to the ASI maps gives optimal agreement between the two observations. We also compare the new FAC method against the traditional triangulation method using pairs of all-sky imagers (ASIs), and against electron density profiles obtained from the Resolute Bay Incoherent Scatter Radar-Canadian radar, both of which are consistent with a characteristic emission height of 200 km.

  3. Inactivation of Tor proteins affects the dynamics of endocytic proteins ...

    Indian Academy of Sciences (India)

    Tor2 is an activator of the Rom2/Rho1 pathway that regulates -factor internalization. Since the recruitment of endocytic proteins such as actin-binding proteins and the amphiphysins precedes the internalization of -factor, we hypothesized that loss of Tor function leads to an alteration in the dynamics of the endocytic ...

  4. mTOR-sensitive translation: Cleared fog reveals more trees.

    Science.gov (United States)

    Masvidal, Laia; Hulea, Laura; Furic, Luc; Topisirovic, Ivan; Larsson, Ola

    2017-10-03

    Translation is fundamental for many biologic processes as it enables cells to rapidly respond to stimuli without requiring de novo mRNA synthesis. The mammalian/mechanistic target of rapamycin (mTOR) is a key regulator of translation. Although mTOR affects global protein synthesis, translation of a subset of mRNAs appears to be exceptionally sensitive to changes in mTOR activity. Recent efforts to catalog these mTOR-sensitive mRNAs resulted in conflicting results. Whereas ribosome-profiling almost exclusively identified 5'-terminal oligopyrimidine (TOP) mRNAs as mTOR-sensitive, polysome-profiling suggested that mTOR also regulates translation of non-TOP mRNAs. This inconsistency was explained by analytical and technical biases limiting the efficiency of ribosome-profiling in detecting mRNAs showing differential translation. Moreover, genome-wide characterization of 5'UTRs of non-TOP mTOR-sensitive mRNAs revealed 2 subsets of transcripts which differ in their requirement for translation initiation factors and biologic functions. We summarize these recent advances and their impact on the understanding of mTOR-sensitive translation.

  5. Role of mTOR Inhibitors in Kidney Disease

    Directory of Open Access Journals (Sweden)

    Moto Kajiwara

    2016-06-01

    Full Text Available The first compound that inhibited the mammalian target of rapamycin (mTOR, sirolimus (rapamycin was discovered in the 1970s as a soil bacterium metabolite collected on Easter Island (Rapa Nui. Because sirolimus showed antiproliferative activity, researchers investigated its molecular target and identified the TOR1 and TOR2. The mTOR consists of mTOR complex 1 (mTORC1 and mTORC2. Rapalogues including sirolimus, everolimus, and temsirolimus exert their effect mainly on mTORC1, whereas their inhibitory effect on mTORC2 is mild. To obtain compounds with more potent antiproliferative effects, ATP-competitive inhibitors of mTOR targeting both mTORC1 and mTORC2 have been developed and tested in clinical trials as anticancer drugs. Currently, mTOR inhibitors are used as anticancer drugs against several solid tumors, and immunosuppressive agents for transplantation of various organs. This review discusses the role of mTOR inhibitors in renal disease with a particular focus on renal cancer, diabetic nephropathy, and kidney transplantation.

  6. Glacial modification of granite tors in the Cairngorms, Scotland

    Science.gov (United States)

    Hall, A.M.; Phillips, W.M.

    2006-01-01

    A range of evidence indicates that many granite tors in the Cairngorms have been modified by the flow of glacier ice during the Pleistocene. Comparisons with SW England and the use of a space-time transformation across 38 tor groups in the Cairngorms allow a model to be developed for progressive glacial modification. Tors with deeply etched surfaces and no, or limited, block removal imply an absence of significant glacial modification. The removal of superstructure and blocks, locally forming boulder trains, and the progressive reduction of tors to stumps and basal slabs represent the more advanced stages of modification. Recognition of some slabs as tor stumps from which glacial erosion has removed all superstructure allows the original distribution of tors to be reconstructed for large areas of the Cairngorms. Unmodified tors require covers of non-erosive, cold-based ice during all of the cold stages of the Middle and Late Pleistocene. Deformation beneath cold-based glacier ice is capable of the removal of blocks but advanced glacial modification requires former wet-based glacier ice. The depth of glacial erosion at former tor sites remains limited largely to the partial or total elimination of the upstanding tor form. Cosmogenic nuclide exposure ages (Phillips et al., 2006) together with data from weathering pit depths (Hall and Phillips, 2006), from the surfaces of tors and large erratic blocks require that the glacial entrainment of blocks from tors occurred in Marine Isotope Stages (MIS) 4-2, 6 and, probably, at least one earlier phase. The occurrence of glacially modified tors on or close to, the main summits of the Cairngorms requires full ice cover over the mountains during these Stages. Evidence from the Cairngorms indicates that tor morphology can be regarded as an important indicator of former ice cover in many formerly glaciated areas, particularly where other evidence of ice cover is sparse. Recognition of the glacial modification of tors is important

  7. Use of Tor (The Onion Router) disallowed from within CERN

    CERN Multimedia

    IT Department

    2008-01-01

    Tor is a freely available system enabling anonymous communication via the Internet between its users. Traffic is encrypted in multiple layers and flows through proxy servers . The use of Tor and similar anonymity systems may interfere with CERN’s security monitoring systems and increases the exposure of the CERN network to malicious or illegal material distributed via so-called "Tor Hidden Services". In addition, Tor has been used to mount attacks, including against CERN computers, and its installation could indicate a break-in. For the above reasons Tor and any similar systems will be added to the list of applications whose use is restricted at CERN and anyone who has used such an application is instructed to no longer do so. If a legitimate professional use can be justified then the Computer Security team should be informed and a prior security check made before installation of the software. CERN IT Department

  8. Comparison of methods and TAT assessment: Volumetric AQUIOS CL and bead-based FACS CANTO II cytometers.

    Science.gov (United States)

    Grossi, Valentina; Infantino, Maria; Meacci, Francesca; Bellio, Emanuele; Bellio, Valerio; Ciotta, Giovanna; Priami, Fiorella; Sarzi-Puttini, Piercarlo; Atzeni, Fabiola; Li Gobbi, Francesca; Damiani, Arianna; Benucci, Maurizio; Manfredi, Mariangela

    2017-01-20

    Measurement of lymphocyte subpopulations is a crucial parameter in the diagnosis and monitoring of therapy in a wide variety of clinical conditions. We compared different flow cytometry-based methods to determine lymphocyte subsets counts of routine samples by volumetric AQUIOS CL (Beckman Coulter) and bead-based FACS CANTO II (BD Biosciences) cytometers. We evaluated the possible decrease of the labor intensive technical work using the fully automated AQUIOS CL system in the pre and post analytical steps in comparison with our routine flow cytometer FACS CANTO II, toward the reduction of laboratory analytical turnaround time (TAT). The analytical performance of AQUIOS CL flow cytometer compared with FACS CANTO II was evaluated testing 224 routine samples, attending the Immunology and Allergology Laboratory Unit, S. Giovanni di Dio Hospital, (Florence, Italy) between September and October 2015. Bland-Altman plot of the differences between the two methods showed an excellent agreement for absolute and percentage counts. Furthermore, the study showed that automated AQUIOS CL system is simple to be used during all analytical steps with a reduction of TAT. In routine conditions, AQUIOS CL flow cytometer could be a suitable tool for subpopulations subset analysis. © 2017 International Clinical Cytometry Society. © 2017 International Clinical Cytometry Society.

  9. Optofluidic biosensors: miniaturized multi-color flow cytometer and fluorescence-activated cell sorter (microFACS)

    Science.gov (United States)

    Cho, Sung Hwan; Chen, Chun-Hao; Lo, Yu-Hwa

    2011-10-01

    We report a portable, low-cost, and high-performance microfluidics based fluorescence-activated cell sorter (microFACS) system to isolate E.coli. cells in combination with a modified specific fluorescence labeling method called tyramide signal amplification-fluorescence in situ hybridization (TSA-FISH). One of the primary challenges in studying bacterial communities that elude cell culturing is to isolate of low abundance bacteria cell from heterogeneous microbial samples. The proposed TSA-FISH protocol is flow cytometry compatible and yields about 10-fold enhancement in fluorescence labeling intensity over widely used standard FISH staining methods. Teflon AF coated optofluidic waveguide and space-time coding with a matched filter algorithm enhance its detection sensitivity. The microFACS is also able to enrich TSA-FISH labeled E.coli. cells by a factor of 223 with an integrated piezoelectric actuator and realtime control electronics system. The microFACS in conjunction with the modified TSA-FISH technologies demonstrates a highly effective and low cost solution potentially for the genomic complexity of complex bacterial communities.

  10. Main results from NILU`s participation in the TOR project; Hovedresultater fra NILUs deltakelse i TOR-prosjektet

    Energy Technology Data Exchange (ETDEWEB)

    Solberg, S.; Stordahl, F.

    1996-01-01

    The conference paper presents the main results from the Norwegian participation in the TOR (Tropospheric Ozone Research) project. The project was a part of the EUROTRAC environment programme which terminated in 1995. The aim of the TOR project was to increase the knowledge on physical and chemical processes being important for the consentration of ozone in the troposphere. 2 refs., 3 figs.

  11. Ecografia na patologia torácica

    Directory of Open Access Journals (Sweden)

    António Bugalho

    2010-07-01

    Full Text Available Resumo: Nos últimos anos a ecografia torácica tem vindo a ser reconhecida como um instrumento de extrema importância para os pneumologistas. Actualmente, os equipamentos são práticos, portáteis, de fácil utilização e fidedignos, o que os torna apropriados para utilização no diagnóstico e orientação de procedimentos terapêuticos.Na avaliação de derrame pleural e condução de toracentese são necessárias competências técnicas básicas em ultra-sonografia. Procedimentos mais complexos devem ser realizados perante treino específico e incluem a colocação de dreno torácico e identificação com eventual biopsia de lesões torácicas.Os autores procuram abordar, de um ponto de vista prático, a técnica e os recentes avanços alcançados neste campo. São apresentados alguns casos clínicos no sentido de ilustrar e guiar aqueles que desejam iniciar a realização de ecografia do tórax.Rev Port Pneumol 2010; XVI (4: 589-606 Abstract: In the past few years transthoracic ultrasound has been recognized as an important tool for chest physicians. At present, ultrasound devices are practical, portable, easy to use and reliable, which makes them suited for diagnostic investigations as well as for therapeutic procedures guidance.Basic ultrasound technical expertise is required to assess pleural effusions and perform ultrasound-guided thoracentesis. More complex procedures can be done with specific training and include assistance to chest drain insertion and identification with potential biopsy of thoracic lesions.The authors aim to review, in a practical approach, the technique and recent developments in this field. Clinical cases are presented in order to illustrate and guide the beginner in chest ultrasound.Rev Port Pneumol 2010; XVI (4: 589-606 Palavras-chave: Ecografia, ultra-sonografia, tórax, pleura, doenças pulmonares, derrame pleural, cancro do pulmão, Key-words: Ultrasound, sonography, chest, thorax, pleura, lung diseases

  12. Ecografia na patologia torácica

    Directory of Open Access Journals (Sweden)

    António Bugalho

    2010-07-01

    Full Text Available Resumo: Nos últimos anos a ecografia torácica tem vindo a ser reconhecida como um instrumento de extrema importância para os pneumologistas. Actualmente, os equipamentos são práticos, portáteis, de fácil utilização e fidedignos, o que os torna apropriados para utilização no diagnóstico e orientação de procedimentos terapêuticos.Na avaliação de derrame pleural e condução de toracentese são necessárias competências técnicas básicas em ultra-sonografia. Procedimentos mais complexos devem ser realizados perante treino específico e incluem a colocação de dreno torácico e identificação com eventual biopsia de lesões torácicas.Os autores procuram abordar, de um ponto de vista prático, a técnica e os recentes avanços alcançados neste campo. São apresentados alguns casos clínicos no sentido de ilustrar e guiar aqueles que desejam iniciar a realização de ecografia do tórax. Abstract: In the past few years transthoracic ultrasound has been recognized as an important tool for chest physicians. At present, ultrasound devices are practical, portable, easy to use and reliable, which makes them suited for diagnostic investigations as well as for therapeutic procedures guidance.Basic ultrasound technical expertise is required to assess pleural effusions and perform ultrasound-guided thoracentesis. More complex procedures can be done with specific training and include assistance to chest drain insertion and identification with potential biopsy of thoracic lesions.The authors aim to review, in a practical approach, the technique and recent developments in this field. Clinical cases are presented in order to illustrate and guide the beginner in chest ultrasound. Palavras-chave: Ecografia, ultra-sonografia, tórax, pleura, doenças pulmonares, derrame pleural, cancro do pulmão, Key-words: Ultrasound, sonography, chest, thorax, pleura, lung diseases, pleural effusion, lung cancer

  13. GMX_FAC: usSEABED facies data for the entire U.S. Gulf of Mexico and Caribbean (Puerto Rico and U.S. Virgin Islands)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The facies data layer (_FAC.txt) is a point coverage of known sediment samplings, inspections, and probings from the usSEABED data collection and integrated using...

  14. National Status and Trends, Benthic Surveillance Project Fluorescent Aromatic Compounds (FAC) Data, 1984-1991, National Centers for Coastal Ocean Science

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The National Status and Trends (NSandT) Benthic Surveillance Fluorescent Aromatic Compounds (FAC) file reports the trace concentrations of Fluorescent Aromatic...

  15. Lysophosphatidic acid acyltransferase beta regulates mTOR signaling.

    Directory of Open Access Journals (Sweden)

    Michelle A Blaskovich

    Full Text Available Lysophosphatidic acid acyltransferase (LPAAT-β is a phosphatidic acid (PA generating enzyme that plays an essential role in triglyceride synthesis. However, LPAAT-β is now being studied as an important regulator of cell growth and differentiation and as a potential therapeutic target in cancer since PA is necessary for the activity of key proteins such as Raf, PKC-ζ and mTOR. In this report we determine the effect of LPAAT-β silencing with siRNA in pancreatic adenocarcinoma cell lines. We show for the first time that LPAAT-β knockdown inhibits proliferation and anchorage-independent growth of pancreatic cancer cells. This is associated with inhibition of signaling by mTOR as determined by levels of mTORC1- and mTORC2-specific phosphorylation sites on 4E-BP1, S6K and Akt. Since PA regulates the activity of mTOR by modulating its binding to FKBP38, we explored the possibility that LPAAT-β might regulate mTOR by affecting its association with FKBP38. Coimmunoprecipitation studies of FKBP38 with mTOR show increased levels of FKBP38 associated with mTOR when LPAAT-β protein levels are knocked down. Furthermore, depletion of LPAAT-β results in increased Lipin 1 nuclear localization which is associated with increased nuclear eccentricity, a nuclear shape change that is dependent on mTOR, further confirming the ability of LPAAT-β to regulate mTOR function. Our results provide support for the hypothesis that PA generated by LPAAT-β regulates mTOR signaling. We discuss the implications of these findings for using LPAAT-β as a therapeutic target.

  16. Obituary: Tor Hagfors, 1930-2007

    Science.gov (United States)

    Aksnes, Kaare

    2007-12-01

    Tor Hagfors, a world leader in the use of radar techniques to observe ionospheres, surfaces and interiors of planetary bodies, died of heart-failure on 17 January 2007, in Puerto Rico, at the age of 76. He was born on 8 December 1930, in Oslo, Norway, and received his education there and in Trondheim, where he graduated with exceptionally good grades with a degree in technical physics from the Norwegian Institute of Technology (NTH) in 1955. Hagfors was then until 1963 employed at the Norwegian Defence Research Establishment (NDRE) where he worked mainly on scattering of high-frequency radio waves in the Earth's ionosphere. This work earned him a PhD in physics from the University of Oslo in 1959. With leave of absence from NDRE, he worked as a Research Associate at Stanford University in 1959/1960, developing a fundamental theory on incoherent scattering of radio waves from electrons in the ionosphere and also participating in radar studies of the Moon's surface in preparation for the later lunar landings. Back in Norway Hagfors continued his scattering studies but, finding that the opportunities for experimental work were limited there, he accepted in 1963 a position at the Massachusetts Institute of Technology's Lincoln Laboratory where he stayed until 1971, interrupted by two years as Director of the Jicamarca Radio Observatory near Lima in Peru 1967-1969. There he gained a reputation as a very inspiring and efficient leader who handled difficult negotiations with the Peruvian military junta very well. In 1971 Hagfors was appointed Director of Operations of the Arecibo Radio Observatory in Puerto Rico, a position that he held and executed in an excellent way until 1973. Although Tor had by now become a United States citizen with a brilliant scientific career, he chose to return to his alma mater, NTH, in Trondheim, where he worked as a Professor of Electronics between 1973 and 1982. From 1975 to 1982 he also served as Director of the European Incoherent Scatter

  17. The photophysics of fac-[Re(CO)3(NN)(bpa)](+) complexes: a theoretical/experimental study.

    Science.gov (United States)

    Sousa, S F; Sampaio, R N; Barbosa Neto, N M; Machado, A E H; Patrocinio, A O T

    2014-08-01

    The influence of the polypyridyl ligand on the photophysics of fac-[Re(CO)3(NN)(bpa)](+), bpa = 1,2-bis-(4-pyridyl)ethane and NN = 1,10-phenanthroline (phen), pyrazino[2,3-f][1,10]-phenanthroline (dpq), and dipyrido[3,2-a:2'3'-c]phenazine (dppz) has been investigated by steady state and time-resolved emission spectroscopy combined with theoretical calculations using time-dependent density functional theory (TD-DFT). The fac-[Re(CO)3(phen)(bpa)](+) is a typical MLCT emitter in acetonitrile with ϕ = 0.11 and τ = 970 ns. The emission lifetime and quantum yield decrease significantly in fac-[Re(CO)3(dpq)(bpa)](+) (ϕ = 0.05; τ = 375 ns) due to the presence of a close lying dark charge transfer state located at the pyrazine ring of dpq, as indicated by TD-DFT data. The luminescence of these complexes is quenched by hydroquinone with kq = (2.9 ± 0.1) × 10(9) and (2.6 ± 0.1) × 10(9) L mol(-1) s(-1), respectively, for NN = phen or dpq. These values are increased respectively to (4.6 ± 0.1) × 10(9) and (4.2 ± 0.1) × 10(9) L mol(-1) s(-1) in the 1 : 1 H2O-CH3CN mixture. In this medium Stern-Volmer constants determined by steady-state and time-resolved measurements differ from each other, which is indicative of static quenching, i.e. the pre-association of hydroquinone and the complexes through hydrogen bonding between the remote N-atom in the bpa ligand (KA ≅ 1-2 × 10(1) L mol(-1)), followed by a concerted proton-electron transfer. In contrast to other investigated complexes, fac-[Re(CO)3(dppz)(bpa)](+) is weakly emissive in acetonitrile at room temperature (ϕ ≅ 10(-4)) and does not exhibit a rigidochromic effect. This photophysical behaviour as well as TD-DFT data indicate that the lowest lying triplet excited state can be described as (3)ILdppz. The results provide additional insight into the influence of the polypyridyl ligand on the photophysical properties of Re(I) complexes.

  18. NAViGaTOR: Network Analysis, Visualization and Graphing Toronto.

    Science.gov (United States)

    Brown, Kevin R; Otasek, David; Ali, Muhammad; McGuffin, Michael J; Xie, Wing; Devani, Baiju; Toch, Ian Lawson van; Jurisica, Igor

    2009-12-15

    NAViGaTOR is a powerful graphing application for the 2D and 3D visualization of biological networks. NAViGaTOR includes a rich suite of visual mark-up tools for manual and automated annotation, fast and scalable layout algorithms and OpenGL hardware acceleration to facilitate the visualization of large graphs. Publication-quality images can be rendered through SVG graphics export. NAViGaTOR supports community-developed data formats (PSI-XML, BioPax and GML), is platform-independent and is extensible through a plug-in architecture. NAViGaTOR is freely available to the research community from http://ophid.utoronto.ca/navigator/. Installers and documentation are provided for 32- and 64-bit Windows, Mac, Linux and Unix. juris@ai.utoronto.ca Supplementary data are available at Bioinformatics online.

  19. The mTOR inhibitor rapamycin has limited acute anticonvulsant effects in mice.

    Directory of Open Access Journals (Sweden)

    Adam L Hartman

    Full Text Available The mammalian target of rapamycin (mTOR pathway integrates signals from different nutrient sources, including amino acids and glucose. Compounds that inhibit mTOR kinase activity such as rapamycin and everolimus can suppress seizures in some chronic animal models and in patients with tuberous sclerosis. However, it is not known whether mTOR inhibitors exert acute anticonvulsant effects in addition to their longer term antiepileptogenic effects. To gain insights into how rapamycin suppresses seizures, we investigated the anticonvulsant activity of rapamycin using acute seizure tests in mice.Following intraperitoneal injection of rapamycin, normal four-week-old male NIH Swiss mice were evaluated for susceptibility to a battery of acute seizure tests similar to those currently used to screen potential therapeutics by the US NIH Anticonvulsant Screening Program. To assess the short term effects of rapamycin, mice were seizure tested in ≤ 6 hours of a single dose of rapamycin, and for longer term effects of rapamycin, mice were tested after 3 or more daily doses of rapamycin.The only seizure test where short-term rapamycin treatment protected mice was against tonic hindlimb extension in the MES threshold test, though this protection waned with longer rapamycin treatment. Longer term rapamycin treatment protected against kainic acid-induced seizure activity, but only at late times after seizure onset. Rapamycin was not protective in the 6 Hz or PTZ seizure tests after short or longer rapamycin treatment times. In contrast to other metabolism-based therapies that protect in acute seizure tests, rapamycin has limited acute anticonvulsant effects in normal mice.The efficacy of rapamycin as an acute anticonvulsant agent may be limited. Furthermore, the combined pattern of acute seizure test results places rapamycin in a third category distinct from both fasting and the ketogenic diet, and which is more similar to drugs acting on sodium channels.

  20. Inactivation of Tor proteins affects the dynamics of endocytic proteins ...

    Indian Academy of Sciences (India)

    2013-04-26

    Apr 26, 2013 ... thereby those can also be considered as aborted patches. Thus, we concluded that the low rate of scission success in the tor mutants is attributed to abortion in endocytosis that might be caused by premature disassembly of Abp1. Strikingly, scission failure increased 4- to 9-fold at both. 30°C and 38°C in tor ...

  1. The mTOR Signalling Pathway in Human Cancer

    Directory of Open Access Journals (Sweden)

    Paula Soares

    2012-02-01

    Full Text Available The conserved serine/threonine kinase mTOR (the mammalian target of rapamycin, a downstream effector of the PI3K/AKT pathway, forms two distinct multiprotein complexes: mTORC1 and mTORC2. mTORC1 is sensitive to rapamycin, activates S6K1 and 4EBP1, which are involved in mRNA translation. It is activated by diverse stimuli, such as growth factors, nutrients, energy and stress signals, and essential signalling pathways, such as PI3K, MAPK and AMPK, in order to control cell growth, proliferation and survival. mTORC2 is considered resistant to rapamycin and is generally insensitive to nutrients and energy signals. It activates PKC-α and AKT and regulates the actin cytoskeleton. Deregulation of multiple elements of the mTOR pathway (PI3K amplification/mutation, PTEN loss of function, AKT overexpression, and S6K1, 4EBP1 and eIF4E overexpression has been reported in many types of cancers, particularly in melanoma, where alterations in major components of the mTOR pathway were reported to have significant effects on tumour progression. Therefore, mTOR is an appealing therapeutic target and mTOR inhibitors, including the rapamycin analogues deforolimus, everolimus and temsirolimus, are submitted to clinical trials for treating multiple cancers, alone or in combination with inhibitors of other pathways. Importantly, temsirolimus and everolimus were recently approved by the FDA for the treatment of renal cell carcinoma, PNET and giant cell astrocytoma. Small molecules that inhibit mTOR kinase activity and dual PI3K-mTOR inhibitors are also being developed. In this review, we aim to survey relevant research, the molecular mechanisms of signalling, including upstream activation and downstream effectors, and the role of mTOR in cancer, mainly in melanoma.

  2. Tails & Tor and other tools for Safeguarding Online Activities

    OpenAIRE

    Abraham, Stephanie; Silva, Tyler; Decourcy, Robert; Cardon, Jim

    2017-01-01

    There are not many known ways to break Tor anonymity, and they require an enormous amount of computational power. Controlling both entrance and exit nodes allows an attacker to compromise client IP with enough pattern analysis. If an .onion or public website does not use SSL, information will not be encrypted once it reaches the exit node. Tor has been successfully broken by Carnegie Mellon, however they will not answer questions nor confirm their method. This research paper investigates Tail...

  3. Caveat mTOR: aberrant signaling disrupts corticogenesis

    OpenAIRE

    Osborne, Lucy R.

    2010-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway is activated in several disorders associated with benign tumors and malformations of the cerebral cortex. In this issue of the JCI, Orlova et al. have now definitively added another disorder to this group by demonstrating that activation of mTOR signaling is associated with polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE), which is characterized by severe intractable epilepsy and megalencephaly. PMSE is caused ...

  4. Trawling for tor hidden services: Detection, measurement, deanonymization

    OpenAIRE

    Biryukov, Alex; Pustogarov, Ivan; Weinmann, Ralf-Philipp

    2013-01-01

    Tor is the most popular volunteer-based anonymity network consisting of over 3000 volunteer-operated relays. Apart from making connections to servers hard to trace to their origin it can also provide receiver privacy for Internet services through a feature called "hidden services". In this paper we expose flaws both in the design and implementation of Tor's hidden services that allow an attacker to measure the popularity of arbitrary hidden services, take down hidden services and deanonymize ...

  5. mTOR Inhibition: From Aging to Autism and Beyond

    Directory of Open Access Journals (Sweden)

    Matt Kaeberlein

    2013-01-01

    Full Text Available The mechanistic target of rapamycin (mTOR is a highly conserved protein that regulates growth and proliferation in response to environmental and hormonal cues. Broadly speaking, organisms are constantly faced with the challenge of interpreting their environment and making a decision between “grow or do not grow.” mTOR is a major component of the network that makes this decision at the cellular level and, to some extent, the tissue and organismal level as well. Although overly simplistic, this framework can be useful when considering the myriad functions ascribed to mTOR and the pleiotropic phenotypes associated with genetic or pharmacological modulation of mTOR signaling. In this review, I will consider mTOR function in this context and attempt to summarize and interpret the growing body of literature demonstrating interesting and varied effects of mTOR inhibitors. These include robust effects on a multitude of age-related parameters and pathologies, as well as several other processes not obviously linked to aging or age-related disease.

  6. Fluorescent activated cell sorting (FACS) combined with gene expression microarrays for transcription enrichment profiling of zebrafish lateral line cells.

    Science.gov (United States)

    Gallardo, Viviana E; Behra, Martine

    2013-08-15

    Transgenic lines carrying fluorescent reporter genes like GFP have been of great value in the elucidation of developmental features and physiological processes in various animal models, including zebrafish. The lateral line (LL), which is a fish specific superficial sensory organ, is an emerging organ model for studying complex cellular processes in the context of the whole living animal. Cell migration, mechanosensory cell development/differentiation and regeneration are some examples. This sensory system is made of superficial and sparse small sensory patches called neuromasts, with less than 50 cells in any given patch. The paucity of cells is a real problem in any effort to characterize those cells at the transcriptional level. We describe here a method which we applied to efficiently separate subpopulation of cells of the LL, using two distinct stable transgenic zebrafish lines, Tg(cldnb:gfp) and Tg(tnks1bp1:EGFP). In both cases, the GFP positive (GFP+) cells were separated from the remainder of the animal by using a Fluorescent Activated Cell Sorter (FACS). The transcripts of the GFP+ cells were subsequently analyzed on gene expression microarrays. The combination of FACS and microarrays is an efficient method to establish a transcriptional signature for discrete cell populations which would otherwise be masked in whole animal preparation. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  7. On Realistically Attacking Tor with Website Fingerprinting

    Directory of Open Access Journals (Sweden)

    Wang Tao

    2016-10-01

    Full Text Available Website fingerprinting allows a local, passive observer monitoring a web-browsing client’s encrypted channel to determine her web activity. Previous attacks have shown that website fingerprinting could be a threat to anonymity networks such as Tor under laboratory conditions. However, there are significant differences between laboratory conditions and realistic conditions. First, in laboratory tests we collect the training data set together with the testing data set, so the training data set is fresh, but an attacker may not be able to maintain a fresh data set. Second, laboratory packet sequences correspond to a single page each, but for realistic packet sequences the split between pages is not obvious. Third, packet sequences may include background noise from other types of web traffic. These differences adversely affect website fingerprinting under realistic conditions. In this paper, we tackle these three problems to bridge the gap between laboratory and realistic conditions for website fingerprinting. We show that we can maintain a fresh training set with minimal resources. We demonstrate several classification-based techniques that allow us to split full packet sequences effectively into sequences corresponding to a single page each. We describe several new algorithms for tackling background noise. With our techniques, we are able to build the first website fingerprinting system that can operate directly on packet sequences collected in the wild.

  8. Akt-dependent and independent mechanisms of mTOR regulation in cancer

    Science.gov (United States)

    Memmott, Regan M.; Dennis, Phillip A.

    2009-01-01

    The protein kinase mTOR (mammalian target of rapamycin) is a critical regulator of cellular metabolism, growth, and proliferation. These processes contribute to tumor formation, and many cancers are characterized by aberrant activation of mTOR. Although activating mutations in mTOR itself have not been identified, deregulation of upstream components that regulate mTOR are prevalent in cancer. The prototypic mechanism of mTOR regulation in cells is through activation of the PI3K/Akt pathway, but mTOR receives input from multiple signaling pathways. This review will discuss Akt-dependent and independent mechanisms of mTOR regulation in response to mitogenic signals, as well as its regulation in response to energy and nutrient-sensing pathways. Preclinical and clinical studies have demonstrated that tumors bearing genetic alterations that activate mTOR are sensitive to pharmacologic inhibition of mTOR. Elucidation of novel pathways that regulate mTOR may help identify predictive factors for sensitivity to mTOR inhibitors and could provide new therapeutic targets for inhibiting the mTOR pathway in cancer. This review will also highlight pharmacologic approaches that inhibit mTOR via activation of the AMP-activated protein kinase (AMPK), an important inhibitor of the mTOR pathway and an emerging target in cancer. PMID:19166931

  9. Pivotal Role of mTOR Signaling in Hepatocellular Carcinoma

    Science.gov (United States)

    Villanueva, Augusto; Chiang, Derek Y.; Newell, Pippa; Peix, Judit; Thung, Swan; Alsinet, Clara; Tovar, Victoria; Roayaie, Sasan; Minguez, Beatriz; Sole, Manel; Battiston, Carlo; van Laarhoven, Stijn; Fiel, Maria I; Di Feo, Analisa; Hoshida, Yujin; Yea, Steven; Toffanin, Sara; Ramos, Alex; Martignetti, John A.; Mazzaferro, Vincenzo; Bruix, Jordi; Waxman, Samuel; Schwartz, Myron; Meyerson, Matthew; Friedman, Scott L.; Llovet, Josep M.

    2008-01-01

    BACKGROUND The advent of targeted therapies in hepatocellular carcinoma (HCC) has underscored the importance of pathway characterization to identify novel molecular targets for treatment. Based on its role in cell growth and differentiation, we evaluated mTOR signaling activation in human HCC, as well as the anti-tumoral effect of a dual-level blockade of the mTOR pathway. METHODS The mTOR pathway was assessed using integrated data from mutation analysis (direct sequencing), DNA copy number changes (SNP-array), mRNA levels (qRT-PCR and gene expression microarray), and protein activation (immunostaining) in 351 human samples, including HCC (n=314), and non-tumoral tissue (n=37). Effects of dual blockade of mTOR signaling using a rapamycin analog (everolimus) and an EGFR/VEGFR inhibitor (AEE788) were evaluated in liver cancer cell lines, and in a tumor xenograft model. RESULTS Aberrant mTOR signaling (phosphorylated-RPS6) was present in half of the cases, associated with IGF pathway activation, EGF upregulation, and PTEN dysregulation. PTEN and PI3KCA-B mutations were rare events. Chromosomal gains in RICTOR (25% of patients) and positive pRPS6 staining correlated with recurrence. RICTOR-specific siRNA downregulation reduced tumor cell viability in vitro. Blockage of mTOR signaling with everolimus in vitro and in a xenograft model decelerated tumor growth and increased survival. This effect was enhanced in vivo after EGFR blockade. CONCLUSIONS MTOR signaling has a critical role in the pathogenesis of HCC, with evidence for the role of RICTOR in tumor oncogenesis. MTOR blockade with everolimus is effective in vivo. These findings establish a rationale for targeting mTOR pathway in clinical trials in HCC. PMID:18929564

  10. Differential mTOR pathway profiles in bladder cancer cell line subtypes to predict sensitivity to mTOR inhibition.

    Science.gov (United States)

    Hau, Andrew M; Nakasaki, Manando; Nakashima, Kazufumi; Krish, Goutam; Hansel, Donna E

    2017-10-01

    Molecular classification of bladder cancer has been increasingly proposed as a potential tool to predict clinical outcomes and responses to chemotherapy. Here we focused on mechanistic target of rapamycin (mTOR) inhibition as a chemotherapeutic strategy and characterized the expression profile of mTOR signaling targets in representative bladder cancer cell lines from basal, luminal, and either basal/luminal ("non-type") molecular subtypes. Protein and mRNA expression of mTOR signaling components from representative luminal (RT4 and RT112), basal (SCaBER and 5637), and nontype (T24 and J82) bladder cancer cell line subtypes were determined by Western blot and database mining analysis of the Cancer Cell Line Encyclopedia. Cell viability following treatment with either, Torin-2 or KU-0063794, 2 dual mTOR complex 1/2 inhibitors, was determined by MTT assay. Immunoblot analysis of cells treated with Torin-2 or KU-0063794 was performed to determine the effects of mTOR inhibition on expression and phosphorylation status of mTOR signaling components, Akt, 4E-BP1, and ribosomal protein S6. Molecular subtypes of bladder cancer cell lines each exhibited a distinct pattern of expression of mTOR-associated genes and baseline phosphorylation level of Akt and 4E-BP1. Cells with low levels of Akt Ser-473 phosphorylation were more resistant to the cytotoxic effects of mTOR inhibition with Torin-2, but not KU-0063794. Exposure to Torin-2 and KU-0063794 both potently and rapidly inhibited phosphorylation of Akt Ser-473 and Thr-308, and 4E-BP1 T37/46 in cell lines that included basal and nontype subtypes. Differential gene expression and protein activity associated with mTOR signaling is observed among bladder cancer cell lines stratified into basal, luminal, and nontype subtypes. Urothelial carcinomas characterized by high baseline Akt Ser-473 phosphorylation may be best suited for targeted mTOR therapies. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Genetic variability of the mTOR pathway and prostate cancer risk in the European Prospective Investigation on Cancer (EPIC.

    Directory of Open Access Journals (Sweden)

    Daniele Campa

    2011-02-01

    Full Text Available The mTOR (mammalian target of rapamycin signal transduction pathway integrates various signals, regulating ribosome biogenesis and protein synthesis as a function of available energy and amino acids, and assuring an appropriate coupling of cellular proliferation with increases in cell size. In addition, recent evidence has pointed to an interplay between the mTOR and p53 pathways. We investigated the genetic variability of 67 key genes in the mTOR pathway and in genes of the p53 pathway which interact with mTOR. We tested the association of 1,084 tagging SNPs with prostate cancer risk in a study of 815 prostate cancer cases and 1,266 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC. We chose the SNPs (n = 11 with the strongest association with risk (p<0.01 and sought to replicate their association in an additional series of 838 prostate cancer cases and 943 controls from EPIC. In the joint analysis of first and second phase two SNPs of the PRKCI gene showed an association with risk of prostate cancer (OR(allele = 0.85, 95% CI 0.78-0.94, p = 1.3 x 10⁻³ for rs546950 and OR(allele = 0.84, 95% CI 0.76-0.93, p = 5.6 x 10⁻⁴ for rs4955720. We confirmed this in a meta-analysis using as replication set the data from the second phase of our study jointly with the first phase of the Cancer Genetic Markers of Susceptibility (CGEMS project. In conclusion, we found an association with prostate cancer risk for two SNPs belonging to PRKCI, a gene which is frequently overexpressed in various neoplasms, including prostate cancer.

  12. Overnutrition, mTOR signaling, and cardiovascular diseases

    Science.gov (United States)

    Jia, Guanghong; Aroor, Annayya R.; Martinez-Lemus, Luis A.

    2014-01-01

    The prevalence of obesity and associated medical disorders has increased dramatically in the United States and throughout much of the world in the past decade. Obesity, induced by excess intake of carbohydrates and fats, is a major cause of Type 2 diabetes, hypertension, and the cardiorenal metabolic syndrome. There is emerging evidence that excessive nutrient intake promotes signaling through the mammalian target of rapamycin (mTOR), which, in turn, may lead to alterations of cellular metabolic signaling leading to insulin resistance and obesity-related diseases, such as diabetes, cardiovascular and kidney disease, as well as cancer. While the pivotal role of mTOR signaling in regulating metabolic stress, autophagy, and adaptive immune responses has received increasing attention, there remain many gaps in our knowledge regarding this important nutrient sensor. For example, the precise cellular signaling mechanisms linking excessive nutrient intake and enhanced mTOR signaling with increased cardiovascular and kidney disease, as well as cancer, are not well understood. In this review, we focus on the effects that the interaction between excess intake of nutrients and enhanced mTOR signaling have on the promotion of obesity-associated diseases and potential therapeutic strategies involving targeting mTOR signaling. PMID:25253086

  13. The mTOR Complex Controls HIV Latency.

    Science.gov (United States)

    Besnard, Emilie; Hakre, Shweta; Kampmann, Martin; Lim, Hyung W; Hosmane, Nina N; Martin, Alyssa; Bassik, Michael C; Verschueren, Erik; Battivelli, Emilie; Chan, Jonathan; Svensson, J Peter; Gramatica, Andrea; Conrad, Ryan J; Ott, Melanie; Greene, Warner C; Krogan, Nevan J; Siliciano, Robert F; Weissman, Jonathan S; Verdin, Eric

    2016-12-14

    A population of CD4 T lymphocytes harboring latent HIV genomes can persist in patients on antiretroviral therapy, posing a barrier to HIV eradication. To examine cellular complexes controlling HIV latency, we conducted a genome-wide screen with a pooled ultracomplex shRNA library and in vitro system modeling HIV latency and identified the mTOR complex as a modulator of HIV latency. Knockdown of mTOR complex subunits or pharmacological inhibition of mTOR activity suppresses reversal of latency in various HIV-1 latency models and HIV-infected patient cells. mTOR inhibitors suppress HIV transcription both through the viral transactivator Tat and via Tat-independent mechanisms. This inhibition occurs at least in part via blocking the phosphorylation of CDK9, a p-TEFb complex member that serves as a cofactor for Tat-mediated transcription. The control of HIV latency by mTOR signaling identifies a pathway that may have significant therapeutic opportunities. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. mTOR Inhibition in Epilepsy: Rationale and Clinical Perspectives

    Science.gov (United States)

    Ostendorf, Adam P.; Wong, Michael

    2015-01-01

    Despite a large number of available medical options, many individuals with epilepsy are refractory to existing therapies that mainly target neurotransmitter or ion channel activity. A growing body of preclinical data has uncovered a molecular pathway that appears crucial in many genetic and acquired epilepsy syndromes. The mammalian target of rapamycin (mTOR) pathway regulates a number of cellular processes required in the growth, metabolism, structure and cell-cell interactions of neurons and glia. Rapamycin and similar compounds inhibit mTOR complex 1 (mTORC1) and decrease seizures, delay seizure development or prevent epileptogenesis in many animal models of mTOR hyperactivation. However, the exact mechanisms by which mTOR inhibition drives decreased seizure activity have not been completely determined. Nonetheless, these preclinical data have led to limited use in humans with epilepsy due to tuberous sclerosis complex (TSC) and polyhydramnios, megalencephaly and symptomatic epilepsy (PMSE) with promising results. Currently, larger controlled studies are underway using mTOR inhibitors in individuals with TSC and intractable epilepsy. PMID:25633849

  15. mTOR inhibition in epilepsy: rationale and clinical perspectives.

    Science.gov (United States)

    Ostendorf, Adam P; Wong, Michael

    2015-02-01

    Despite a large number of available medical options, many individuals with epilepsy are refractory to existing therapies that mainly target neurotransmitter or ion channel activity. A growing body of preclinical data has uncovered a molecular pathway that appears crucial in many genetic and acquired epilepsy syndromes. The mammalian target of rapamycin (mTOR) pathway regulates a number of cellular processes required in the growth, metabolism, structure, and cell-cell interactions of neurons and glia. Rapamycin and similar compounds inhibit mTOR complex 1 and decrease seizures, delay seizure development, or prevent epileptogenesis in many animal models of mTOR hyperactivation. However, the exact mechanisms by which mTOR inhibition drives decreased seizure activity have not been completely determined. Nonetheless, these preclinical data have led to limited use in humans with epilepsy due to tuberous sclerosis complex and polyhydramnios, megalencephaly, and symptomatic epilepsy with promising results. Currently, larger controlled studies are underway using mTOR inhibitors in individuals with tuberous sclerosis complex and intractable epilepsy.

  16. Efficient Tor signaling requires a functional class C Vps protein complex in Saccharomyces cerevisiae.

    Science.gov (United States)

    Zurita-Martinez, Sara A; Puria, Rekha; Pan, Xuewen; Boeke, Jef D; Cardenas, Maria E

    2007-08-01

    The Tor kinases regulate responses to nutrients and control cell growth. Unlike most organisms that only contain one Tor protein, Saccharomyces cerevisiae expresses two, Tor1 and Tor2, which are thought to share all of the rapamycin-sensitive functions attributable to Tor signaling. Here we conducted a genetic screen that defined the global TOR1 synthetic fitness or lethal interaction gene network. This screen identified mutations in distinctive functional categories that impaired vacuolar function, including components of the EGO/Gse and PAS complexes that reduce fitness. In addition, tor1 is lethal in combination with mutations in class C Vps complex components. We find that Tor1 does not regulate the known function of the class C Vps complex in protein sorting. Instead class C vps mutants fail to recover from rapamycin-induced growth arrest or to survive nitrogen starvation and have low levels of amino acids. Remarkably, addition of glutamate or glutamine restores viability to a tor1 pep3 mutant strain. We conclude that Tor1 is more effective than Tor2 at providing rapamycin-sensitive Tor signaling under conditions of amino acid limitation, and that an intact class C Vps complex is required to mediate intracellular amino acid homeostasis for efficient Tor signaling.

  17. Synthesis, characterization and relativistic DFT studies of fac-Re(CO)3(isonicotinic acid)2Cl complex

    Science.gov (United States)

    Zúñiga, César; Oyarzún, Diego P.; Martin-Transaco, Rudy; Yáñez-S, Mauricio; Tello, Alejandra; Fuentealba, Mauricio; Cantero-López, Plinio; Arratia-Pérez, Ramiro

    2017-11-01

    In this work, new fac-Re(CO)3(PyCOOH)2Cl from isonicotinic acid ligand has been prepared. The complex was characterized by structural (single-crystal X-ray diffraction), elemental analysis and spectroscopic (FTIR, NMR, UV-vis spectroscopy) methods. DFT and TDDFT calculations were performed to obtain the electronic transitions involved in their UV-Vis spectrum. The excitation energies agree with the experimental results. The TDDFT calculations suggest that experimental mixed absorption bands at 270 and 314 nm could be assigned to (MLCT-LLCT)/MLCT transitions. Natural Bond Orbitals (NBO) approach has enabled studying the effects of bonding interactions. E(2) energies confirm the occurrence of ICT (Intra-molecular Charge Transfer) within the molecule.

  18. Clickable, Hydrophilic Ligand for fac-[MI(CO)3]+ (M = Re/99mTc) Applied in an S-Functionalized ?-MSH Peptide

    OpenAIRE

    Kasten, Benjamin B.; Ma, Xiaowei; Liu, Hongguang; Hayes, Thomas R.; Barnes, Charles L.; Qi, Shibo; Cheng, Kai; Bottorff, Shalina C.; Slocumb, Winston S.; Wang, Jing; Cheng, Zhen; Benny, Paul D.

    2014-01-01

    The copper(I)-catalyzed azide?alkyne cycloaddition (CuAAC) click reaction was used to incorporate alkyne-functionalized dipicolylamine (DPA) ligands (1 and 3) for fac-[MI(CO)3]+ (M = Re/99mTc) complexation into an ?-melanocyte stimulating hormone (?-MSH) peptide analogue. A novel DPA ligand with carboxylate substitutions on the pyridyl rings (3) was designed to increase the hydrophilicity and to decrease in vivo hepatobiliary retention of fac-[99mTcI(CO)3]+ complexes used in single photon emi...

  19. mTOR inhibitors response and mTOR pathway in pancreatic neuroendocrine tumors.

    Science.gov (United States)

    Falletta, Simona; Partelli, Stefano; Rubini, Corrado; Nann, Dominik; Doria, Andrea; Marinoni, Ilaria; Polenta, Vanessa; Di Pasquale, Carmelina; Degli Uberti, Ettore; Perren, Aurel; Falconi, Massimo; Zatelli, Maria Chiara

    2016-11-01

    Medical therapy of pancreatic neuroendocrine tumors (P-NET) may take advantage of Everolimus treatment. However, the extent of therapeutic response cannot be predicted. This study was aimed to identify the possible predictive markers of response to Everolimus in P-NET. We found that Everolimus reduced the cell viability and induced apoptosis in primary cultures of 6 P-NET (P-NET-R), where the proliferative and antiapoptotic effects of IGF1 were blocked by Everolimus. On the contrary, 14 P-NET primary cultures (P-NET-NR) were resistant to Everolimus and IGF1, suggesting an involvement of PI3K/AKT/mTOR pathway in the mechanism of resistance. The response to Everolimus in vitro was associated with an active AKT/mTOR pathway and seemed to be associated with a greater clinical aggressiveness. In addition, a patient sensitive to Everolimus in vitro was sensitive to this drug in vivo also and showed a positive p-AKT immunohistochemistry (IHC) at tissue level. Similarly, a patient resistant to Everolimus treatment after surgery was not sensitive to the drug in vitro and had a negative p-AKT IHC staining. Therefore, present data confirm that P-NET primary cultures may be considered a model for testing medical treatment efficacy and that IHC characterization of p-AKT might help in identifying human P-NET who can benefit from Everolimus treatment. These data encourage conducting a prospective multicenter study involving different groups of P-NET patients treated with Everolimus. © 2016 Society for Endocrinology.

  20. Introductory TORS training in an otolaryngology residency program.

    Science.gov (United States)

    Fastenberg, Judd H; Gibber, Marc J; Smith, Richard V

    2018-02-07

    Transoral robotic surgery (TORS) is becoming an integral part of the otolaryngology resident experience. While there is widespread agreement that a formal, validated curriculum for TORS training is needed for residents, none presently exists. The primary objective of this study is to evaluate an introductory resident curriculum for TORS training that could be easily adopted at other institutions. This is a prospective study of otolaryngology residents (PGY1-5) in an academic medical center from 2015 to 2016. Trainees completed an introductory TORS training program consisting of online modules, logistic training, and hands-on training consisting of 12 tasks on the da Vinci Skills Simulator (dVSS). The primary outcomes were completion of training and time to completion. The secondary outcomes included resident attitudes regarding TORS as reflected on post-training survey. A total of 20 resident trainees participated in the study. 85% of trainees completed the hands-on robotic training in the allotted 3-h time limit. The average time to completion for those who finished was 91.53 min (SD 33.59 min). There was no statistically significant correlation between time to completion and PGY, number of robotic first assists, or total number of robotic cases. An introductory, resident-directed TORS training curriculum using the dVSS on an active surgical console is feasible in an academic medical center and may contribute to basic robotic competency among residents. Institutions with a dVSS may replicate this training in a resource-efficient manner prior to implementation of more comprehensive training. Robotic skills are likely trainable and independent from surgical skills learned during residency.

  1. The Sniper Attack: Anonymously Deanonymizing and Disabling the Tor Network

    Science.gov (United States)

    2014-02-01

    adversarial entry relay that stops reading from the connection to a target middle relay; in version 2 the 3The Tor software provides parameters, EntryNodes and...e. g., due to TCP connections timing out.) 3) Evaluation: We implemented the described out-of- memory (oom) circuit killing as a Tor software patch...ping-o-death. html. [40] S. Savage, N. Cardwell, D. Wetherall, and T. Anderson, “TCP Con- gestion Control with a Misbehaving Receiver,” ACM SIGCOMM CCR

  2. Attenuation of trace organic compounds (TOrCs) inbioelectrochemical systems

    KAUST Repository

    Werner, Craig M.

    2015-04-01

    Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are two types of microbial bioelectrochemical systems (BESs) that use microorganisms to convert chemical energy in wastewaters into useful energy products such as (bio)electricity (MFC) or hydrogen gas (MEC). These two systems were evaluated for their capacity to attenuate trace organic compounds (TOrCs), commonly found in municipal wastewater, under closed circuit (current generation) and open circuit (no current generation) conditions, using acetate as the carbon source. A biocide was used to evaluate attenuation in terms of biotransformation versus sorption. The difference in attenuation observed before and after addition of the biocide represented biotransformation, while attenuation after addition of a biocide primarily indicated sorption. Attenuation of TOrCs was similar in MFCs and MECs for eight different TOrCs, except for caffeine and trimethoprim where slightly higher attenuation was observed in MECs. Electric current generation did not enhance attenuation of the TOrCs except for caffeine, which showed slightly higher attenuation under closed circuit conditions in both MFCs and MECs. Substantial sorption of the TOrCs occurred to the biofilm-covered electrodes, but no consistent trend could be identified regarding the physico-chemical properties of the TOrCs tested and the extent of sorption. The octanol-water distribution coefficient at pH 7.4 (log DpH 7.4) appeared to be a reasonable predictor for sorption of some of the compounds (carbamazepine, atrazine, tris(2-chloroethyl) phosphate and diphenhydramine) but not for others (N,N-Diethyl-meta-toluamide). Atenolol also showed high levels of sorption despite being the most hydrophilic in the suite of compounds studied (log DpH 7.4=-1.99). Though BESs do not show any inherent advantages over conventional wastewater treatment, with respect to TOrC removal, overall removals in BESs are similar to that reported for conventional wastewater

  3. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid.

    Directory of Open Access Journals (Sweden)

    Jae Sung You

    Full Text Available Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis.

  4. Mechanical stimulation induces mTOR signaling via an ERK-independent mechanism: implications for a direct activation of mTOR by phosphatidic acid.

    Science.gov (United States)

    You, Jae Sung; Frey, John W; Hornberger, Troy A

    2012-01-01

    Signaling by mTOR is a well-recognized component of the pathway through which mechanical signals regulate protein synthesis and muscle mass. However, the mechanisms involved in the mechanical regulation of mTOR signaling have not been defined. Nevertheless, recent studies suggest that a mechanically-induced increase in phosphatidic acid (PA) may be involved. There is also evidence which suggests that mechanical stimuli, and PA, utilize ERK to induce mTOR signaling. Hence, we reasoned that a mechanically-induced increase in PA might promote mTOR signaling via an ERK-dependent mechanism. To test this, we subjected mouse skeletal muscles to mechanical stimulation in the presence or absence of a MEK/ERK inhibitor, and then measured several commonly used markers of mTOR signaling. Transgenic mice expressing a rapamycin-resistant mutant of mTOR were also used to confirm the validity of these markers. The results demonstrated that mechanically-induced increases in p70(s6k) T389 and 4E-BP1 S64 phosphorylation, and unexpectedly, a loss in total 4E-BP1, were fully mTOR-dependent signaling events. Furthermore, we determined that mechanical stimulation induced these mTOR-dependent events, and protein synthesis, through an ERK-independent mechanism. Similar to mechanical stimulation, exogenous PA also induced mTOR-dependent signaling via an ERK-independent mechanism. Moreover, PA was able to directly activate mTOR signaling in vitro. Combined, these results demonstrate that mechanical stimulation induces mTOR signaling, and protein synthesis, via an ERK-independent mechanism that potentially involves a direct interaction of PA with mTOR. Furthermore, it appears that a decrease in total 4E-BP1 may be part of the mTOR-dependent mechanism through which mechanical stimuli activate protein synthesis.

  5. A Recollection of mTOR Signaling in Learning and Memory

    Science.gov (United States)

    Graber, Tyson E.; McCamphill, Patrick K.; Sossin, Wayne S.

    2013-01-01

    Mechanistic target of rapamcyin (mTOR) is a central player in cell growth throughout the organism. However, mTOR takes on an additional, more specialized role in the developed neuron, where it regulates the protein synthesis-dependent, plastic changes underlying learning and memory. mTOR is sequestered in two multiprotein complexes (mTORC1 and…

  6. Dietary interventions that reduce mTOR activity rescue autistic-like behavioral deficits in mice

    NARCIS (Netherlands)

    Wu, Jiangbo; de Theije, Caroline G M; Lopes da Silva, Sofia; Abbring, Suzanne; van der Horst, Hilma; Broersen, Laus M; Willemsen, Linette; Kas, Martien J; Garssen, Johan; Kraneveld, Aletta D

    Enhanced mammalian target of rapamycin (mTOR) signaling in the brain has been implicated in the pathogenesis of autism spectrum disorder (ASD). Inhibition of the mTOR pathway improves behavior and neuropathology in mouse models of ASD containing mTOR-associated single gene mutations. The current

  7. Dietary interventions that reduce mTOR activity rescue autistic-like behavioral deficits in mice

    NARCIS (Netherlands)

    Wu, Jiangbo; de Theije, Caroline G M; da Silva, Sofia Lopes; Abbring, Suzanne; van der Horst, Hilma; Broersen, Laus M; Willemsen, Linette; Kas, Martien; Garssen, Johan; Kraneveld, Aletta D

    2016-01-01

    Enhanced mammalian target of rapamycin (mTOR) signaling in the brain has been implicated in the pathogenesis of autism spectrum disorder (ASD). Inhibition of the mTOR pathway improves behavior and neuropathology in mouse models of ASD containing mTOR-associated single gene mutations. The current

  8. Asymmetric distribution of the ionospheric electric potential in the opposite hemispheres as inferred from the SuperDARN observations and FAC-based convection model

    DEFF Research Database (Denmark)

    Lukianova, R.; Hanuise, C.; Christiansen, Freddy

    2008-01-01

    We compare the SuperDARN convection patterns with the predictions of a new numerical model of the global distribution of ionospheric electric potentials. The model utilizes high-precision statistical maps of field-aligned currents (FAC) derived from measurements made by polar-orbiting low-altitud...

  9. An improved flow cytometric method using FACS lysing solution for measurement of ZAP-70 expression in B-cell chronic lymphocytic leukemia

    NARCIS (Netherlands)

    Bekkema, Roelof; Tadema, Afke; Daenen, Simon M. G. J.; Kluin-Nelemans, Hanneke C.; Mulder, Andre B.

    Background: B-cell expression of ZAP-70, normally expressed in T and NK cells, correlates with poor prognosis in B-CLL. Poor discrimination between ZAP-70 positive and negative cells hampers routine application of flow cytometry. We examined the usefulness of FACS Lysing Solution. Methods: ZAP-70

  10. Waterfilling: Balancing the Tor network with maximum diversity

    Directory of Open Access Journals (Sweden)

    Rochet Florentin

    2017-04-01

    Full Text Available We present the Waterfilling circuit selection method, which we designed in order to mitigate the risks of a successful end-to-end traffic correlation attack. Waterfilling proceeds by balancing the Tor network load as evenly as possible on endpoints of user paths. We simulate the use of Waterfilling thanks to the TorPS and Shadow tools. Applying several security metrics, we show that the adoption of Waterfilling considerably increases the number of nodes that an adversary needs to control in order to be able to mount a successful attack, while somewhat decreasing the minimum amount of bandwidth required to do so. Moreover, we evaluate Waterfilling in Shadow and show that it does not impact significantly the performance of the network. Furthermore, Waterfilling reduces the benefits that an attacker could obtain by hacking into a top bandwidth Tor relay, hence limiting the risks raised by such relays. Waterfilling does not require any major change in Tor, and can co-exist with the current circuit selection algorithm.

  11. Molecular mechanisms of mTOR regulation by stress.

    Science.gov (United States)

    Heberle, Alexander Martin; Prentzell, Mirja Tamara; van Eunen, Karen; Bakker, Barbara Marleen; Grellscheid, Sushma Nagaraja; Thedieck, Kathrin

    2015-01-01

    Tumors are prime examples of cell growth in unfavorable environments that elicit cellular stress. The high metabolic demand and insufficient vascularization of tumors cause a deficiency of oxygen and nutrients. Oncogenic mutations map to signaling events via mammalian target of rapamycin (mTOR), metabolic pathways, and mitochondrial function. These alterations have been linked with cellular stresses, in particular endoplasmic reticulum (ER) stress, hypoxia, and oxidative stress. Yet tumors survive these challenges and acquire highly energy-demanding traits, such as overgrowth and invasiveness. In this review we focus on stresses that occur in cancer cells and discuss them in the context of mTOR signaling. Of note, many tumor traits require mTOR complex 1 (mTORC1) activity, but mTORC1 hyperactivation eventually sensitizes cells to apoptosis. Thus, mTORC1 activity needs to be balanced in cancer cells. We provide an overview of the mechanisms contributing to mTOR regulation by stress and suggest a model wherein stress granules function as guardians of mTORC1 signaling, allowing cancer cells to escape stress-induced cell death.

  12. Akt-dependent and independent mechanisms of mTOR regulation in cancer

    OpenAIRE

    Memmott, Regan M.; Dennis, Phillip A.

    2009-01-01

    The protein kinase mTOR (mammalian target of rapamycin) is a critical regulator of cellular metabolism, growth, and proliferation. These processes contribute to tumor formation, and many cancers are characterized by aberrant activation of mTOR. Although activating mutations in mTOR itself have not been identified, deregulation of upstream components that regulate mTOR are prevalent in cancer. The prototypic mechanism of mTOR regulation in cells is through activation of the PI3K/Akt pathway, b...

  13. Cholera outbreaks in the El Tor biotype era and the impact of the new El Tor variants.

    Science.gov (United States)

    Mukhopadhyay, Asish K; Takeda, Yoshifumi; Balakrish Nair, G

    2014-01-01

    Vibrio cholerae O1, the causative agent of the disease cholera, has two biotypes namely the classical and El Tor. Biotype is a subspecific taxonomic classification of V. cholerae O1. Differentiation of V. cholerae strains into biotype does not alter the clinical management of cholera but is of immense public health and epidemiological importance in identifying the source and spread of infection, particularly when V. cholerae is first isolated in a country or geographic area. From recorded history, till date, the world has experienced seven pandemics of cholera. Among these, the first six pandemics are believed to have been caused by the classical biotype whereas the ongoing seventh pandemic is caused by the El Tor biotype. In recent years, new pathogenic variants of V. cholerae have emerged and spread throughout many Asian and African countries with corresponding cryptic changes in the epidemiology of cholera. In this chapter, we describe the outbreaks during the seventh pandemic El Tor biotype era spanning more than five decades along with the recent advances in our understanding of the development, evolution, spread, and impact of the new variants of El Tor strains.

  14. The nuclear import of ribosomal proteins is regulated by mTOR

    Science.gov (United States)

    Kazyken, Dubek; Kaz, Yelimbek; Kiyan, Vladimir; Zhylkibayev, Assylbek A.; Chen, Chien-Hung; Agarwal, Nitin K.; Sarbassov, Dos D.

    2014-01-01

    Mechanistic target of rapamycin (mTOR) is a central component of the essential signaling pathway that regulates cell growth and proliferation by controlling anabolic processes in cells. mTOR exists in two distinct mTOR complexes known as mTORC1 and mTORC2 that reside mostly in cytoplasm. In our study, the biochemical characterization of mTOR led to discovery of its novel localization on nuclear envelope where it associates with a critical regulator of nuclear import Ran Binding Protein 2 (RanBP2). We show that association of mTOR with RanBP2 is dependent on the mTOR kinase activity that regulates the nuclear import of ribosomal proteins. The mTOR kinase inhibitors within thirty minutes caused a substantial decrease of ribosomal proteins in the nuclear but not cytoplasmic fraction. Detection of a nuclear accumulation of the GFP-tagged ribosomal protein rpL7a also indicated its dependence on the mTOR kinase activity. The nuclear abundance of ribosomal proteins was not affected by inhibition of mTOR Complex 1 (mTORC1) by rapamycin or deficiency of mTORC2, suggesting a distinctive role of the nuclear envelope mTOR complex in the nuclear import. Thus, we identified that mTOR in association with RanBP2 mediates the active nuclear import of ribosomal proteins. PMID:25294810

  15. mTOR, a Potential Target to Treat Autism Spectrum Disorder.

    Science.gov (United States)

    Sato, Atsushi

    2016-01-01

    Mammalian target of rapamycin (mTOR) is a key regulator in various cellular processes, including cell growth, gene expression, and synaptic functions. Autism spectrum disorder (ASD) is frequently accompanied by monogenic disorders, such as tuberous sclerosis complex, phosphatase and tensin homolog tumor hamartoma syndrome, neurofibromatosis 1, and fragile X syndrome, in which mTOR is hyperactive. Mutations in the genes involved in the mTOR-mediated signaling pathway have been identified in some cases of syndromic ASD. Evidences indicate a pathogenic role for hyperactive mTOR-mediated signaling in ASD associated with these monogenic disorders, and mTOR inhibitors are a potential pharmacotherapy for ASD. Abnormal synaptic transmission through metabotropic glutamate receptor 5 may underlie in a part of ASD associated with hyperactive mTOR-mediated signaling. In this review, the relationship between mTOR and ASD is discussed.

  16. A mammalian cell based FACS-panning platform for the selection of HIV-1 envelopes for vaccine development.

    Directory of Open Access Journals (Sweden)

    Tim-Henrik Bruun

    Full Text Available An increasing number of broadly neutralizing monoclonal antibodies (bnMAb against the HIV-1 envelope (Env protein has been discovered recently. Despite this progress, vaccination efforts with the aim to re-elicit bnMAbs that provide protective immunity have failed so far. Herein, we describe the development of a mammalian cell based FACS-panning method in which bnMAbs are used as tools to select surface-exposed envelope variants according to their binding affinity. For that purpose, an HIV-1 derived lentiviral vector was developed to infect HEK293T cells at low multiplicity of infection (MOI in order to link Env phenotype and genotype. For proof of principle, a gp145 Env model-library was established in which the complete V3 domain was substituted by five strain specific V3 loop sequences with known binding affinities to nMAb 447-52D, respectively. Env genes were recovered from selected cells by PCR, subcloned into a lentiviral vector (i to determine and quantify the enrichment nMAb binders and (ii to generate a new batch of transduction competent particles. After 2 selection cycles the Env variant with highest affinity was enriched 20-fold and represented 80% of the remaining Env population. Exploiting the recently described bnMAbs, this procedure might prove useful in selecting Env proteins from large Env libraries with the potential to elicit bnMAbs when used as vaccine candidates.

  17. TOR-Dependent and -Independent Pathways Regulate Autophagy in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Yunting Pu

    2017-07-01

    Full Text Available Autophagy is a critical process for recycling of cytoplasmic materials during environmental stress, senescence and cellular remodeling. It is upregulated under a wide range of abiotic stress conditions and is important for stress tolerance. Autophagy is repressed by the protein kinase target of rapamycin (TOR, which is activated in response to nutrients and in turn upregulates cell growth and translation and inhibits autophagy. Down-regulation of TOR in Arabidopsis thaliana leads to constitutive autophagy and to decreased growth, but the relationship to stress conditions is unclear. Here, we assess the extent to which TOR controls autophagy activation by abiotic stress. Overexpression of TOR inhibited autophagy activation by nutrient starvation, salt and osmotic stress, indicating that activation of autophagy under these conditions requires down-regulation of TOR activity. In contrast, TOR overexpression had no effect on autophagy induced by oxidative stress or ER stress, suggesting that activation of autophagy by these conditions is independent of TOR function. The plant hormone auxin has been shown previously to up-regulate TOR activity. To confirm the existence of two pathways for activation of autophagy, dependent on the stress conditions, auxin was added exogenously to activate TOR, and the effect on autophagy under different conditions was assessed. Consistent with the effect of TOR overexpression, the addition of the auxin NAA inhibited autophagy during nutrient deficiency, salt and osmotic stress, but not during oxidative or ER stress. NAA treatment was unable to block autophagy induced by a TOR inhibitor or by a mutation in the TOR complex component RAPTOR1B, indicating that auxin is upstream of TOR in the regulation of autophagy. We conclude that repression of auxin-regulated TOR activity is required for autophagy activation in response to a subset of abiotic stress conditions.

  18. Pasteurella multocida toxin- induced osteoclastogenesis requires mTOR activation.

    Science.gov (United States)

    Kloos, Bianca; Chakraborty, Sushmita; Lindner, Sonja G; Noack, Katrin; Harre, Ulrike; Schett, Georg; Krämer, Oliver H; Kubatzky, Katharina F

    2015-09-14

    Pasteurella multocida toxin (PMT) is a potent inducer of osteoclast formation. Pigs suffering from an infection with toxigenic Pasteurella multocida strains develop atrophic rhinitis characterised by a loss of turbinate bones and conchae. However, on the molecular level the process of bone loss remains largely uncharacterised. Recently it was found that PMT activates the serine/threonine kinase mammalian target of rapamycin (mTOR) in fibroblasts. Using RAW264.7 macrophages, we investigated the role of the mTOR complex 1 (mTORC1) in PMT-mediated osteoclast formation. PMT induces the differentiation of RAW264.7 macrophages into multinucleated, tartrate resistant acid phosphatase (TRAP) positive osteoclasts that are capable to resorb bone. In the presence of the mTORC1 inhibitor rapamycin, PMT was significantly less able to induce the formation of TRAP-positive osteoclasts. Accordingly, the resulting resorption of bone was strongly reduced. A major target of mTOR is the 70 kDa ribosomal protein S6 kinase 1 (p70 S6K1). Activated p70 S6K1 decreases the expression of programmed cell death protein 4 (PDCD4), a negative transcriptional regulator of osteoclastogenesis, at the protein and gene level. Ultimately this results in the activation of c-Jun, a component of the activator protein 1 (AP-1) complex, which is a major transcription factor for the induction of osteoclast-specific genes. We now demonstrate that c-Jun and its downstream target, the osteoclast-specific bone degrading protease cathepsin K, are upregulated upon PMT treatment in an mTOR-dependent manner. Activation of mTOR signalling plays a central role in the formation of osteoclasts through the bacterial toxin PMT. On the molecular level, PMT-induced activation of mTOR leads to down regulation of PDCD4, a known repressor of AP-1 complex, culminating in the activation of c-Jun, an essential transcription factor for triggering osteoclastogenesis.

  19. Study of field-aligned current (FAC), interplanetary electric field component (Ey), interplanetary magnetic field component (Bz), and northward (x) and eastward (y) components of geomagnetic field during supersubstorm

    Science.gov (United States)

    Adhikari, Binod; Dahal, Subodh; Chapagain, Narayan P.

    2017-05-01

    A dominant process by which energy and momentum are transported from the magnetosphere to the ionosphere is known as field-aligned current (FAC). It is enhanced during magnetic reconnection and explosive energy release at a substorm. In this paper, we studied FAC, interplanetary electric field component (Ey), interplanetary magnetic field component (Bz), and northward (x) and eastward (y) components of geomagnetic field during three events of supersubstorm occurred on 24 November 2001, 21 January 2005, and 24 August 2005. Large-scale FAC, supposed to be produced during supersubstorm (SSS), has potentiality to cause blackout on Earth. We examined temporal variations of the x and y components of high-latitude geomagnetic field during SSS, which is attributed to the FACs. We shall report the characteristics of high-latitude northward and eastward components of geomagnetic field variation during the growth phase of SSS by the implementation of discrete wavelet transform (DWT) and cross-correlation analysis. Among three examples of SSS events, the highest peak value of FAC was estimated to be 19 μAm-2. This is shore up with the prediction made by Parks (1991) and Stasiewicz et al. (1998) that the FACs may vary from a few tens to several hundred μAm-2. Although this peak value of FACs for SSS event is much higher than the average FACs associated with regular substorms or magnetic storms, it is expedient and can be expect for SSS events which might be due to very high density solar wind plasma parcels (PPs) triggering the SSS events. In all events, during growth phase, the FAC increases to extremely high level and the geomagnetic northward component decreases to extremely low level. This represents a strong positive correlation between FAC and geomagnetic northward component. The DWT analysis accounts that the highest amplitude of the wavelet coefficients indicates singularities present in FAC during SSS event. But the amplitude of squared wavelet coefficient is found

  20. Resveratrol induces autophagy by directly inhibiting mTOR through ATP competition

    Science.gov (United States)

    Park, Dohyun; Jeong, Heeyoon; Lee, Mi Nam; Koh, Ara; Kwon, Ohman; Yang, Yong Ryoul; Noh, Jungeun; Suh, Pann-Ghill; Park, Hwangseo; Ryu, Sung Ho

    2016-01-01

    Resveratrol (RSV) is a natural polyphenol that has a beneficial effect on health, and resveratrol-induced autophagy has been suggested to be a key process in mediating many beneficial effects of resveratrol, such as reduction of inflammation and induction of cancer cell death. Although various resveratrol targets have been suggested, the molecule that mediates resveratrol-induced autophagy remains unknown. Here, we demonstrate that resveratrol induces autophagy by directly inhibiting the mTOR-ULK1 pathway. We found that inhibition of mTOR activity and presence of ULK1 are required for autophagy induction by resveratrol. In line with this mTOR dependency, we found that resveratrol suppresses the viability of MCF7 cells but not of SW620 cells, which are mTOR inhibitor sensitive and insensitive cancer cells, respectively. We also found that resveratrol-induced cancer cell suppression occurred ULK1 dependently. For the mechanism of action of resveratrol on mTOR inhibition, we demonstrate that resveratrol directly inhibits mTOR. We found that resveratrol inhibits mTOR by docking onto the ATP-binding pocket of mTOR (i.e., it competes with ATP). We propose mTOR as a novel direct target of resveratrol, and inhibition of mTOR is necessary for autophagy induction. PMID:26902888

  1. Caveat mTOR: aberrant signaling disrupts corticogenesis.

    Science.gov (United States)

    Osborne, Lucy R

    2010-05-01

    The mammalian target of rapamycin (mTOR) signaling pathway is activated in several disorders associated with benign tumors and malformations of the cerebral cortex. In this issue of the JCI, Orlova et al. have now definitively added another disorder to this group by demonstrating that activation of mTOR signaling is associated with polyhydramnios, megalencephaly, and symptomatic epilepsy syndrome (PMSE), which is characterized by severe intractable epilepsy and megalencephaly. PMSE is caused by lack of the pseudokinase STE20-related kinase adaptor alpha (STRADalpha), and Orlova et al. show that reduction of STRADalpha levels during corticogenesis in the mouse results in a cellular phenotype and neuronal migration defects similar to those observed in patients with PMSE, clearly demonstrating a pivotal role for STRADalpha in cell polarity and growth. This study helps pave the way for possible therapeutic intervention with rapamycin to control the epilepsy and learning disabilities associated with this disorder.

  2. A Legume TOR Protein Kinase Regulates Rhizobium Symbiosis and Is Essential for Infection and Nodule Development.

    Science.gov (United States)

    Nanjareddy, Kalpana; Blanco, Lourdes; Arthikala, Manoj-Kumar; Alvarado-Affantranger, Xóchitl; Quinto, Carmen; Sánchez, Federico; Lara, Miguel

    2016-11-01

    The target of rapamycin (TOR) protein kinase regulates metabolism, growth, and life span in yeast, animals, and plants in coordination with nutrient status and environmental conditions. The nutrient-dependent nature of TOR functionality makes this kinase a putative regulator of symbiotic associations involving nutrient acquisition. However, TOR's role in these processes remains to be understood. Here, we uncovered the role of TOR during the bean (Phaseolus vulgaris)-Rhizobium tropici (Rhizobium) symbiotic interaction. TOR was expressed in all tested bean tissues, with higher transcript levels in the root meristems and senesced nodules. We showed TOR promoter expression along the progressing infection thread and in the infected cells of mature nodules. Posttranscriptional gene silencing of TOR using RNA interference (RNAi) showed that this gene is involved in lateral root elongation and root cell organization and also alters the density, size, and number of root hairs. The suppression of TOR transcripts also affected infection thread progression and associated cortical cell divisions, resulting in a drastic reduction of nodule numbers. TOR-RNAi resulted in reduced reactive oxygen species accumulation and altered CyclinD1 and CyclinD3 expression, which are crucial factors for infection thread progression and nodule organogenesis. Enhanced expression of TOR-regulated ATG genes in TOR-RNAi roots suggested that TOR plays a role in the recognition of Rhizobium as a symbiont. Together, these data suggest that TOR plays a vital role in the establishment of root nodule symbiosis in the common bean. © 2016 American Society of Plant Biologists. All Rights Reserved.

  3. mTOR Inhibition in Epilepsy: Rationale and Clinical Perspectives

    OpenAIRE

    Ostendorf, Adam P.; Wong, Michael

    2015-01-01

    Despite a large number of available medical options, many individuals with epilepsy are refractory to existing therapies that mainly target neurotransmitter or ion channel activity. A growing body of preclinical data has uncovered a molecular pathway that appears crucial in many genetic and acquired epilepsy syndromes. The mammalian target of rapamycin (mTOR) pathway regulates a number of cellular processes required in the growth, metabolism, structure and cell-cell interactions of neurons an...

  4. Department of Zoology, Fac

    African Journals Online (AJOL)

    USER

    2015-01-07

    Jan 7, 2015 ... abundant species in the forest were Leptopelis macrotis, Phlyctimantis boulengeri and. Nectophryne afra each having ... Key Words: Distribution, Diversity, Nigeria, Vegetation, Forest and Savanna. Introduction. The first major threat to .... as under stones, fallen wood, panels, plastics and amongst leaf litter.

  5. Unequivocal identification of subpopulations in putative multiclonal Trypanosoma cruzi strains by FACs single cell sorting and genotyping.

    Directory of Open Access Journals (Sweden)

    Helder Magno Silva Valadares

    Full Text Available Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and current conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (FACS was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations--Silvio X10 cl1 (TcI and Esmeraldo cl3 (TcII--and three naturally occurring strains, one isolated from a vector (A316A R7 and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality.

  6. CHO-K1 host cells adapted to growth in glutamine-free medium by FACS-assisted evolution.

    Science.gov (United States)

    Bort, Juan A Hernández; Stern, Beate; Borth, Nicole

    2010-10-01

    During the process of recombinant cell line optimisation for production of biopharmaceuticals, multiple cellular properties like robustness against stress, the attainment of high cell concentrations and maintenance of high viability must be considered to maximize protein yield. To improve growth and viability, glutamine is supplemented as an alternative energy source for rapidly dividing cells that oxidize glucose inefficiently. However, the resulting by-product ammonia is toxic at high concentrations and has a negative impact on protein glycosylation, a major quality-determining parameter of biopharmaceuticals. In this work, the CHO-K1 cell line was adapted to a chemically defined medium and suspension growth within 3 weeks. Subsequently, the glutamine concentration was stepwise reduced from 8 to 4 and 2 mM. After each reduction, both the final cell concentration in the batch and the viability decreased. To force a rapid evolution of cells to achieve high final cell concentrations, cells were seeded at high densities (10(7) cells/mL) and surviving cells were sorted by FACS or MACS when viability declined to 10% (typically after 24 h). Sorted cells were grown in batch until viability declined to 10% and viable cells recovered again. The final sorted population was able to reach comparable or even better viable cell concentrations and showed a significantly improved viability compared to their ancestors. The 2 mM glutamine-adapted cell line was directly transferred into glutamine-free medium and was able to grow at comparable rates without requiring further adaptation. Cells compensated the lack of glutamine by increasing their consumption of glutamate and aspartate.

  7. mTOR and the health benefits of exercise.

    Science.gov (United States)

    Watson, Kurt; Baar, Keith

    2014-12-01

    Exercise is the greatest physiological stress that our bodies experience. For example, during maximal endurance exercise in elite athlete's cardiac output can increase up to 8-fold and the working muscles receive 21-times more blood each minute than at rest. Given the physiological stress associated with exercise and the adaptations that occur to handle this stress, it is not surprising that exercise training is known to prevent or effectively treat a multitude of degenerative conditions including cardiovascular disease, cancer, diabetes, depression, Alzheimer's disease, Parkinson's disease, and many others. Many of the health benefits of exercise are mediated by the mammalian/mechanistic target of rapamycin (mTOR), either in complex 1 or 2, not only within the working muscle, but also in distant tissues such as fat, liver, and brain. This review will discuss how exercise activates mTOR in diverse tissues and the ways that mTOR is important in the adaptive response that makes us bigger, stronger, and healthier as a result of exercise. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. The TSC-mTOR pathway regulates macrophage polarization

    Science.gov (United States)

    Byles, Vanessa; Covarrubias, Anthony J.; Ben-Sahra, Issam; Lamming, Dudley W.; Sabatini, David M.; Manning, Brendan D.; Horng, Tiffany

    2013-01-01

    Macrophages are able to polarize to proinflammatory M1 or alternative M2 states with distinct phenotypes and physiological functions. How metabolic status regulates macrophage polarization remains not well understood, and here we examine the role of mTOR (Mechanistic Target of Rapamycin), a central metabolic pathway that couples nutrient sensing to regulation of metabolic processes. Using a mouse model in which myeloid lineage specific deletion of Tsc1 (Tsc1Δ/Δ) leads to constitutive mTOR Complex 1 (mTORC1) activation, we find that Tsc1Δ/Δ macrophages are refractory to IL-4 induced M2 polarization, but produce increased inflammatory responses to proinflammatory stimuli. Moreover, mTORC1-mediated downregulation of Akt signaling critically contributes to defective polarization. These findings highlight a key role for the mTOR pathway in regulating macrophage polarization, and suggest how nutrient sensing and metabolic status could be “hard-wired” to control of macrophage function, with broad implications for regulation of Type 2 immunity, inflammation, and allergy. PMID:24280772

  9. Optimizing Managed Aquifer Recharge (MAR) Systems for Removal of Trace Organic Chemicals (TOrCs)

    KAUST Repository

    Alidina, Mazahirali

    2014-06-01

    Managed aquifer recharge (MAR) is a low-energy subsurface water treatment system with the potential of being an important component of sustainable water reuse schemes. Alongside common wastewater contaminants, MAR systems have been shown to attenuate a range of trace organic chemicals (TOrCs). Despite several factors being possibly important for TOrC attenuation, many have not been investigated in depth. This research effort investigated three factors affecting attenuation of the moderately degradable TOrCs: primary substrate, adaptation of the microbial community to presence of TOrCs, and groundwater temperature. The overall goal was to optimize TOrC attenuation using different MAR configurations considering how these factors affect TOrC attenuation. The primary substrate composition and concentration significantly impacted attenuation of the moderately degradable TOrCs. Lower primary substrate concentrations and more refractory carbon generally resulted in better TOrC transformation, a more diverse microbial community in the infiltration zone and more diverse capabilities for TOrC degradation. The enzyme group cytochrome P450 may be important for TOrC transformation since its genes were more abundant under carbon-starving primary substrate conditions. Adaptation of the microbial community by pre-exposure to TOrCs was not required in order to degrade them. However, adaptation to the primary substrate was necessary for TOrC biotransformation due to its effect on the microbial community. Attenuation of most TOrCs was unaffected by changes in temperature. Some moderately degradable TOrCs, however, were better attenuated at higher temperatures likely due to increased microbial activity. Others were better degraded at lower temperatures likely due to favorable sorption conditions. In the context of applying MAR systems to potential water reuse schemes within Saudi Arabia, a reconnaissance study of TOrC occurrence in treated wastewater effluents was undertaken. Most of

  10. mTOR regulates peripheral nerve response to tensile strain.

    Science.gov (United States)

    Love, James M; Bober, Brian G; Orozco, Elisabeth; White, Amanda T; Bremner, Shannon N; Lovering, Richard M; Schenk, Simon; Shah, Sameer B

    2017-05-01

    While excessive tensile strain can be detrimental to nerve function, strain can be a positive regulator of neuronal outgrowth. We used an in vivo rat model of sciatic nerve strain to investigate signaling mechanisms underlying peripheral nerve response to deformation. Nerves were deformed by 11% and did not demonstrate deficits in compound action potential latency or amplitude during or after 6 h of strain. As revealed by Western blotting, application of strain resulted in significant upregulation of mammalian target of rapamycin (mTOR) and S6 signaling in nerves, increased myelin basic protein (MBP) and β-actin levels, and increased phosphorylation of neurofilament subunit H (NF-H) compared with unstrained (sham) contralateral nerves (P nerve tubulin levels compared with unstrained controls. Systemic rapamycin treatment, thought to selectively target mTOR complex 1 (mTORC1), suppressed mTOR/S6 signaling, reduced levels of MBP and overall tubulin, and decreased NF-H phosphorylation in nerves strained for 6 h, revealing a role for mTOR in increasing MBP expression and NF-H phosphorylation, and maintaining tubulin levels. Consistent with stretch-induced increases in MBP, immunolabeling revealed increased S6 signaling in Schwann cells of stretched nerves compared with unstretched nerves. In addition, application of strain to cultured adult dorsal root ganglion neurons showed an increase in axonal protein synthesis based on a puromycin incorporation assay, suggesting that neuronal translational pathways also respond to strain. This work has important implications for understanding mechanisms underlying nerve response to strain during development and regeneration.NEW & NOTEWORTHY Peripheral nerves experience tensile strain (stretch) during development and movement. Excessive strain impairs neuronal function, but moderate strains are accommodated by nerves and can promote neuronal growth; mechanisms underlying these phenomena are not well understood. We demonstrated

  11. The Role of Mammalian Target of Rapamycin (mTOR) in Insulin Signaling.

    Science.gov (United States)

    Yoon, Mee-Sup

    2017-10-27

    The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that controls a wide spectrum of cellular processes, including cell growth, differentiation, and metabolism. mTOR forms two distinct multiprotein complexes known as mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), which are characterized by the presence of raptor and rictor, respectively. mTOR controls insulin signaling by regulating several downstream components such as growth factor receptor-bound protein 10 (Grb10), insulin receptor substrate (IRS-1), F-box/WD repeat-containing protein 8 (Fbw8), and insulin like growth factor 1 receptor/insulin receptor (IGF-IR/IR). In addition, mTORC1 and mTORC2 regulate each other through a feedback loop to control cell growth. This review outlines the current understanding of mTOR regulation in insulin signaling in the context of whole body metabolism.

  12. Plasticity and mTOR: Towards Restoration of Impaired Synaptic Plasticity in mTOR-Related Neurogenetic Disorders

    Directory of Open Access Journals (Sweden)

    Tanjala T. Gipson

    2012-01-01

    Full Text Available Objective. To review the recent literature on the clinical features, genetic mutations, neurobiology associated with dysregulation of mTOR (mammalian target of rapamycin, and clinical trials for tuberous sclerosis complex (TSC, neurofibromatosis-1 (NF1 and fragile X syndrome (FXS, and phosphatase and tensin homolog hamartoma syndromes (PTHS, which are neurogenetic disorders associated with abnormalities in synaptic plasticity and mTOR signaling. Methods. Pubmed and Clinicaltrials.gov were searched using specific search strategies. Results/Conclusions. Although traditionally thought of as irreversible disorders, significant scientific progress has been made in both humans and preclinical models to understand how pathologic features of these neurogenetic disorders can be reduced or reversed. This paper revealed significant similarities among the conditions. Not only do they share features of impaired synaptic plasticity and dysregulation of mTOR, but they also share clinical features—autism, intellectual disability, cutaneous lesions, and tumors. Although scientific advances towards discovery of effective treatment in some disorders have outpaced others, progress in understanding the signaling pathways that connect the entire group indicates that the lesser known disorders will become treatable as well.

  13. Plasticity and mTOR: towards restoration of impaired synaptic plasticity in mTOR-related neurogenetic disorders.

    Science.gov (United States)

    Gipson, Tanjala T; Johnston, Michael V

    2012-01-01

    To review the recent literature on the clinical features, genetic mutations, neurobiology associated with dysregulation of mTOR (mammalian target of rapamycin), and clinical trials for tuberous sclerosis complex (TSC), neurofibromatosis-1 (NF1) and fragile X syndrome (FXS), and phosphatase and tensin homolog hamartoma syndromes (PTHS), which are neurogenetic disorders associated with abnormalities in synaptic plasticity and mTOR signaling. Pubmed and Clinicaltrials.gov were searched using specific search strategies. Although traditionally thought of as irreversible disorders, significant scientific progress has been made in both humans and preclinical models to understand how pathologic features of these neurogenetic disorders can be reduced or reversed. This paper revealed significant similarities among the conditions. Not only do they share features of impaired synaptic plasticity and dysregulation of mTOR, but they also share clinical features--autism, intellectual disability, cutaneous lesions, and tumors. Although scientific advances towards discovery of effective treatment in some disorders have outpaced others, progress in understanding the signaling pathways that connect the entire group indicates that the lesser known disorders will become treatable as well.

  14. Metformin induces degradation of mTOR protein in breast cancer cells.

    Science.gov (United States)

    Alalem, Mohamed; Ray, Alpana; Ray, Bimal K

    2016-11-01

    Activation of mTOR is implicated in the development and progression of breast cancer. mTOR inhibition exhibited promising antitumor effects in breast cancer; however, its effect is compromised by several feedback mechanisms. One of such mechanisms is the upregulation of mTOR pathway in breast cancer cells. Despite the established role of mTOR activation in breast cancer, the status of total mTOR protein and its impact on the tumor behavior and response to treatment are poorly understood. Besides, the mechanisms underlying mTOR protein degradation in normal and cancer breast cells are still largely unknown. We and others found that total mTOR protein level is elevated in breast cancer cells compared to their nonmalignant counterparts. We have detected defective proteolysis of mTOR protein in breast cancer cells, which could, at least in part, explain the high level of mTOR protein in these cells. We show that metformin treatment in MCF-7 breast cancer cells induced degradation of mTOR and sequestration of this protein in a perinuclear region. The decrease in mTOR protein level in these cells correlated positively with a concomitant inhibition of proliferation and migration potentials of these cells. These findings provided a novel mechanism for the metformin action in breast cancer treatment. Understanding the proteolytic mechanism responsible for mTOR level in breast cancer may pave the way for improving the efficacy of breast cancer treatment regimens and mitigating drug resistance as well as providing a basis for potential novel therapeutic modalities for breast cancer. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  15. Muscle inactivation of mTOR causes metabolic and dystrophin defects leading to severe myopathy

    Science.gov (United States)

    Risson, Valérie; Mazelin, Laetitia; Roceri, Mila; Sanchez, Hervé; Moncollin, Vincent; Corneloup, Claudine; Richard-Bulteau, Hélène; Vignaud, Alban; Baas, Dominique; Defour, Aurélia; Freyssenet, Damien; Tanti, Jean-François; Le-Marchand-Brustel, Yannick; Ferrier, Bernard; Conjard-Duplany, Agnès; Romanino, Klaas; Bauché, Stéphanie; Hantaï, Daniel; Mueller, Matthias; Kozma, Sara C.; Thomas, George; Rüegg, Markus A.; Ferry, Arnaud; Pende, Mario; Bigard, Xavier; Koulmann, Nathalie

    2009-01-01

    Mammalian target of rapamycin (mTOR) is a key regulator of cell growth that associates with raptor and rictor to form the mTOR complex 1 (mTORC1) and mTORC2, respectively. Raptor is required for oxidative muscle integrity, whereas rictor is dispensable. In this study, we show that muscle-specific inactivation of mTOR leads to severe myopathy, resulting in premature death. mTOR-deficient muscles display metabolic changes similar to those observed in muscles lacking raptor, including impaired oxidative metabolism, altered mitochondrial regulation, and glycogen accumulation associated with protein kinase B/Akt hyperactivation. In addition, mTOR-deficient muscles exhibit increased basal glucose uptake, whereas whole body glucose homeostasis is essentially maintained. Importantly, loss of mTOR exacerbates the myopathic features in both slow oxidative and fast glycolytic muscles. Moreover, mTOR but not raptor and rictor deficiency leads to reduced muscle dystrophin content. We provide evidence that mTOR controls dystrophin transcription in a cell-autonomous, rapamycin-resistant, and kinase-independent manner. Collectively, our results demonstrate that mTOR acts mainly via mTORC1, whereas regulation of dystrophin is raptor and rictor independent. PMID:20008564

  16. An Enhancing Security Research of Tor Anonymous Communication to Against DDos Attacks

    Directory of Open Access Journals (Sweden)

    Feng Tao

    2017-01-01

    Full Text Available Tor (The Second Onion Router is modified by the first generation onion router and known as the most prevalent anonymous communication system. According to the advantage of low latency, high confidentiality of transmission content, high security of communication channels and et al., Tor is widely used in anonymous Web browsing, instant message and so on. However, the vulnerability and blemish of Tor affect system security. An identity and Signcryption-based concurrent signature scheme was used to prevent the behaviors of attackers from inserting controlled nodes and conspiring to make DDos attacks. The integrated security of Tor system was enhanced in our scheme. In addition we have proved the scheme.

  17. The making of a queen: TOR pathway is a key player in diphenic caste development.

    Directory of Open Access Journals (Sweden)

    Avani Patel

    2007-06-01

    Full Text Available Honey bees (Apis mellifera provide a principal example of diphenic development. Excess feeding of female larvae results in queens (large reproductives. Moderate diet yields workers (small helpers. The signaling pathway that links provisioning to female developmental fate is not understood, yet we reasoned that it could include TOR (target of rapamycin, a nutrient- and energy-sensing kinase that controls organismal growth.Here, the role of Apis mellifera TOR (amTOR in caste determination is examined by rapamycin/FK506 pharmacology and RNA interference (RNAi gene knockdown. We show that in queen-destined larvae, the TOR inhibitor rapamycin induces the development of worker characters that are blocked by the antagonist FK506. Further, queen fate is associated with elevated activity of the Apis mellifera TOR encoding gene, amTOR, and amTOR gene knockdown blocks queen fate and results in individuals with worker morphology.A much-studied insect dimorphism, thereby, can be governed by the TOR pathway. Our results present the first evidence for a role of TOR in diphenic development, and suggest that adoption of this ancestral nutrient-sensing cascade is one evolutionary pathway for morphological caste differentiation in social insects.

  18. Vasopressin activates Akt/mTOR pathway in smooth muscle cells cultured in high glucose concentration

    Energy Technology Data Exchange (ETDEWEB)

    Montes, Daniela K.; Brenet, Marianne; Muñoz, Vanessa C.; Burgos, Patricia V.; Villanueva, Carolina I. [Department of Physiology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); Figueroa, Carlos D. [Department of Anatomy, Histology and Pathology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); González, Carlos B., E-mail: cbgonzal@uach.cl [Department of Physiology, Universidad Austral de Chile, Valdivia 509-9200 (Chile); Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555 (United States)

    2013-11-29

    Highlights: •AVP induces mTOR phosphorylation in A-10 cells cultured in high glucose concentration. •The mTOR phosphorylation is mediated by the PI3K/Akt pathway activation. •The AVP-induced mTOR phosphorylation inhibited autophagy and stimulated cell proliferation. -- Abstract: Mammalian target of rapamycin (mTOR) complex is a key regulator of autophagy, cell growth and proliferation. Here, we studied the effects of arginine vasopressin (AVP) on mTOR activation in vascular smooth muscle cells cultured in high glucose concentration. AVP induced the mTOR phosphorylation in A-10 cells grown in high glucose, in contrast to cells cultured in normal glucose; wherein, only basal phosphorylation was observed. The AVP-induced mTOR phosphorylation was inhibited by a PI3K inhibitor. Moreover, the AVP-induced mTOR activation inhibited autophagy and increased thymidine incorporation in cells grown in high glucose. This increase was abolished by rapamycin which inhibits the mTORC1 complex formation. Our results suggest that AVP stimulates mTOR phosphorylation by activating the PI3K/Akt signaling pathway and, subsequently, inhibits autophagy and raises cell proliferation in A-10 cells maintained in high glucose concentration.

  19. Antibiotic Susceptibility Patterns of Vibrio cholerae isolates

    Directory of Open Access Journals (Sweden)

    S D Shrestha

    2010-09-01

    Full Text Available INTRODUCTION: Cholera is one of the most common diarrhoeal diseases in Nepal. Etiological agent of cholera is Vibrio cholerae which removes essential body fluids, salts and vital nutrients, which are necessary for life causing dehydration and malnutrition. Emerging antimicrobial resistant is common. The aim of the present study was to determine the antibiotic susceptibility pattern of cholera patients in Nepal. METHODS: All the laboratory works were conducted in the bacteriology section of National Public Health Laboratory, Teku from March to September 2005. During this period a total of 340 stool samples from diarrhoeal patients were collected and processed according to the standard laboratory methods. Each patient suffering from diarrhoea was directly interviewed for his or her clinical history during sample collection. RESULTS: A total of 340 stool samples were processed and studied from both sex including all ages of patients. Among the processed sample 53 Vibrio cholerae cases were found. All isolated Vibrio cholerae O1 were El Tor, Inaba. All isolated (100% Vibrio cholerae O1 were sensitive to Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline whereas all were resistant to Nalidixic acid and Cotrimoxazole. Only 15.1% cases were sensitive to Furazolidone whereas 84.9% were resistant. CONCLUSION: All V. cholerae strains isolated in this study were found resistant to Multi Drug Resistant (resistant to at least two antibiotics of different group. Ampicillin, Ciprofloxacin, Erythromycin and Tetracycline were found still more potent antibiotics against Vibrio cholerae isolated during the study. Keywords: antibiotics, susceptibility, Vibrio cholera.

  20. Global Proteomics Revealed Klebsiella pneumoniae Induced Autophagy and Oxidative Stress in Caenorhabditis elegans by Inhibiting PI3K/AKT/mTOR Pathway during Infection

    Directory of Open Access Journals (Sweden)

    Arumugam Kamaladevi

    2017-09-01

    Full Text Available The enterobacterium, Klebsiella pneumoniae invades the intestinal epithelium of humans by interfering with multiple host cell response. To uncover a system-level overview of host response during infection, we analyzed the global dynamics of protein profiling in Caenorhabditis elegans using quantitative proteomics approach. Comparison of protein samples of nematodes exposed to K. pneumoniae for 12, 24, and 36 h by 2DE revealed several changes in host proteome. A total of 266 host-encoded proteins were identified by 2DE MALDI-MS/MS and LC-MS/MS and the interacting partners of the identified proteins were predicted by STRING 10.0 analysis. In order to understand the interacting partners of regulatory proteins with similar or close pI ranges, a liquid IEF was performed and the isolated fractions containing proteins were identified by LC-MS/MS. Functional bioinformatics analysis on identified proteins deciphered that they were mostly related to the metabolism, dauer formation, apoptosis, endocytosis, signal transduction, translation, developmental, and reproduction process. Gene enrichment analysis suggested that the metabolic process as the most overrepresented pathway regulated against K. pneumoniae infection. The dauer-like formation in infected C. elegans along with intestinal atrophy and ROS during the physiological analysis indicated that the regulation of metabolic pathway is probably through the involvement of mTOR. Immunoblot analysis supported the above notion that the K. pneumoniae infection induced protein mis-folding in host by involving PI3Kinase/AKT-1/mTOR mediated pathway. Furthermore, the susceptibility of pdi-2, akt-1, and mTOR C. elegans mutants confirmed the role and involvement of PI3K/AKT/mTOR pathway in mediating protein mis-folding which appear to be translating the vulnerability of host defense toward K. pneumoniae infection.

  1. The geomorphic impact of glaciers as indicated by tors in North Sweden (Aurivaara, 68° N)

    Science.gov (United States)

    André, Marie-Françoise

    2004-02-01

    Geomorphological investigations carried out on 15 tor-like features located on the Aurivaara plateau (North Sweden, 68° N) provide new insights in the greatly debated age of these landforms. Erratics and till trapped deep in the tor joints support a pre-Weichselian age for tor formation. Moreover, the occurrence of various weathering stages in allochtonous material, the joint width up to 1.5 m (requiring long-term weathering), and the frequent association of tors with pediment-like forms, suggest pre-Quaternary tor formation. The juxtaposition of fresh erratics and in situ old weathering features (mushroom rocks, concentrically weathered well-rounded corestones, and grus) indicates a predominantly cold-based regime for the Scandinavian ice sheet, with erratics carried by the overlying moving ice being repeatedly deposited on tor summits during deglaciation phases. The relationships between tors and ice action indicated for the Aurivaara plateau result in the proposal of a morphodynamical succession of five tor subtypes ranging from the preservation of well-rounded corestones still embedded in grus (suggesting negligible glacial erosion) to the almost complete removal of tor features by ice scouring. A comparison with tors in similar geological and topographical contexts from the unglaciated Dartmoor area allows a tentative evaluation of an average overall glacial erosion of 0-10 m on the northern Sweden plateaus, in sharp contrast with the 190 m overdeepening of the nearby Torneträsk basin. Thus, this case study of Swedish tors provides additional support to the recent interpretations of relict landscapes in previously glaciated areas and is in accordance with the classical «model» of glacial selective erosion established in the Nordic and Arctic mountains.

  2. The role of mTOR signaling in Alzheimer disease.

    Science.gov (United States)

    Oddo, Salvatore

    2012-01-01

    The buildup of Abeta and tau is believed to directly cause or contribute to the progressive cognitive deficits characteristic of Alzheimer disease. However, the molecular pathways linking Abeta and tau accumulation to learning and memory deficits remain elusive. There is growing evidence that soluble forms of Abeta and tau can obstruct learning and memory by interfering with several signaling cascades. In this review, I will present data showing that the mammalian target of rapamycin (mTOR) may play a role in Abeta and tau induced neurodegeneration.

  3. Ruptura bronquial secundaria a traumatismo torácico cerrado

    OpenAIRE

    Castañeda, Enrique; AZABACHE, Verónica; FRANCHI, Luis Miguel; BAZAN, Noé

    2013-01-01

    Las rupturas bronquiales como consecuencia de traumatismo cerrado de tórax son eventos raros (1,2). Por su rareza y por el hecho de tener dos modos diferentes de presentación pueden dilatar considerablemente el diagnóstico. Dependiendo de su localización anatómica y extensión pueden ser: a) extrapleurales, sin manifestación clínica importante que permita el diagnóstico temprano; y b) intrapleurales, donde el aire escapa al espacio pleural y con la inserción del drenaje torácico, se establece ...

  4. The ever-evolving role of mTOR in translation.

    Science.gov (United States)

    Fonseca, Bruno D; Smith, Ewan M; Yelle, Nicolas; Alain, Tommy; Bushell, Martin; Pause, Arnim

    2014-12-01

    Control of translation allows for the production of stoichiometric levels of each protein in the cell. Attaining such a level of fine-tuned regulation of protein production requires the coordinated temporal and spatial control of numerous cellular signalling cascades impinging on the various components of the translational machinery. Foremost among these is the mTOR signalling pathway. The mTOR pathway regulates both the initiation and elongation steps of protein synthesis through the phosphorylation of numerous translation factors, while simultaneously ensuring adequate folding of nascent polypeptides through co-translational degradation of misfolded proteins. Perhaps most remarkably, mTOR is also a key regulator of the synthesis of ribosomal proteins and translation factors themselves. Two seminal studies have recently shown in translatome analysis that the mTOR pathway preferentially regulates the translation of mRNAs encoding ribosomal proteins and translation factors. Therefore, the role of the mTOR pathway in the control of protein synthesis extends far beyond immediate translational control. By controlling ribosome production (and ultimately ribosome availability), mTOR is a master long-term controller of protein synthesis. Herein, we review the literature spanning the early discoveries of mTOR on translation to the latest advances in our understanding of how the mTOR pathway controls the synthesis of ribosomal proteins. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  5. Inhibition of mTOR promotes hyperthermia sensitivity in SMMC-7721 human hepatocellular carcinoma cell line

    Science.gov (United States)

    WANG, QING-LIANG; LIU, BO; LI, XIAO-JIE; HU, KUN-PENG; ZHAO, KUN; YE, XIAO-MING

    2016-01-01

    The mammalian target of rapamycin (mTOR) is a critical mediator of the phosphoinositide 3-kinase/protein kinase B/mTOR signaling pathway, and mTOR activity is induced following heat shock. Thermotherapy is used to treat hepatocellular carcinoma (HCC). However, the role of mTOR in modulating thermosensitivity in HCC has yet to be elucidated. In the present study, the antisense plasmid pEGFP-C1-mTOR was transfected into SMMC-7721 cells, and the expression levels of mTOR were analyzed by reverse transcription-polymerase chain reaction and western blot analysis. The thermal responses of the transfected cells were also examined. The results revealed that SMMC-7721 cells were sensitive to heat treatment, and cell viability was significantly inhibited following hyperthermia treatment (P<0.01). The mRNA and protein expression levels of mTOR decreased post-transfection. Cell proliferation, colony-forming ability and motility were all significantly decreased following hyperthermia treatment in the transfected cells. Flow cytometry analysis demonstrated that apoptosis was significantly increased following treatment (P<0.01). The number of cells in S phase was increased, and the cell cycle was arrested in S phase. In conclusion, inhibition of mTOR increased the thermosensitivity of SMMC-7721 cells by increasing cellular apoptosis and inducing S phase arrest. PMID:26998020

  6. The AKT-mTOR signalling pathway in kidney cancer tissues

    Science.gov (United States)

    Spirina, L. V.; Usynin, Y. A.; Kondakova, I. V.; Yurmazov, Z. A.; Slonimskaya, E. M.; Kolegova, E. S.

    2015-11-01

    An increased expression of phospho-AKT, m-TOR, glycogen regulator GSK-3-beta and transcription inhibitor 4E-BP1 was observed in kidney cancer tissues. Tumor size growth was associated with a high level of c-Raf and low content of phospho-m-TOR. Cancer metastasis development led to a decreased PTEN and phospho-AKT expression.

  7. Finding a better drug for epilepsy: the mTOR pathway as an antiepileptogenic target.

    NARCIS (Netherlands)

    Galanopoulou, A.S.; Gorter, J.A.; Cepeda, C.

    2012-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway regulates cell growth, differentiation, proliferation, and metabolism. Loss-of-function mutations in upstream regulators of mTOR have been highly associated with dysplasias, epilepsy, and neurodevelopmental disorders. These include tuberous

  8. mTOR as a Key Regulator in Maintaining Skeletal Muscle Mass

    Directory of Open Access Journals (Sweden)

    Mee-Sup Yoon

    2017-10-01

    Full Text Available Maintenance of skeletal muscle mass is regulated by the balance between anabolic and catabolic processes. Mammalian target of rapamycin (mTOR is an evolutionarily conserved serine/threonine kinase, and is known to play vital roles in protein synthesis. Recent findings have continued to refine our understanding of the function of mTOR in maintaining skeletal muscle mass. mTOR controls the anabolic and catabolic signaling of skeletal muscle mass, resulting in the modulation of muscle hypertrophy and muscle wastage. This review will highlight the fundamental role of mTOR in skeletal muscle growth by summarizing the phenotype of skeletal-specific mTOR deficiency. In addition, the evidence that mTOR is a dual regulator of anabolism and catabolism in skeletal muscle mass will be discussed. A full understanding of mTOR signaling in the maintenance of skeletal muscle mass could help to develop mTOR-targeted therapeutics to prevent muscle wasting.

  9. Exercise increases mTOR signaling in brain regions involved in cognition and emotional behavior.

    Science.gov (United States)

    Lloyd, Brian A; Hake, Holly S; Ishiwata, Takayuki; Farmer, Caroline E; Loetz, Esteban C; Fleshner, Monika; Bland, Sondra T; Greenwood, Benjamin N

    2017-04-14

    Exercise can enhance learning and memory and produce resistance against stress-related psychiatric disorders such as depression and anxiety. In rats, these beneficial effects of exercise occur regardless of exercise controllability: both voluntary and forced wheel running produce stress-protective effects. The mechanisms underlying these beneficial effects of exercise remain unknown. The mammalian target of rapamycin (mTOR) is a translation regulator important for cell growth, proliferation, and survival. mTOR has been implicated in enhancing learning and memory as well as antidepressant effects. Moreover, mTOR is sensitive to exercise signals such as metabolic factors. The effects of exercise on mTOR signaling, however, remain unknown. The goal of the present study was to test the hypothesis that exercise, regardless of controllability, increases levels of phosphorylated mTOR (p-mTOR) in brain regions important for learning and emotional behavior. Rats were exposed to 6 weeks of either sedentary (locked wheel), voluntary, or forced wheel running conditions. At 6 weeks, rats were sacrificed during peak running and levels of p-mTOR were measured using immunohistochemistry. Overall, both voluntary and forced exercise increased p-mTOR-positive neurons in the medial prefrontal cortex, striatum, hippocampus, hypothalamus, and amygdala compared to locked wheel controls. Exercise, regardless of controllability, also increased numbers of p-mTOR-positive glia in the striatum, hippocampus, and amygdala. For both neurons and glia, the largest increase in p-mTOR positive cells was observed after voluntary running, with forced exercise causing a more modest increase. Interestingly, voluntary exercise preferentially increased p-mTOR in astrocytes (GFAP+), while forced running increased p-mTOR in microglia (CD11+) in the inferior dentate gyrus. Results suggest that mTOR signaling is sensitive to exercise, but subtle differences exist depending on exercise controllability

  10. Correction of both spontaneous and DEB-induced chromosome instability in Fanconi anemia FA-C cells by FACC cDNA

    Energy Technology Data Exchange (ETDEWEB)

    Stavropoulos, D.J.; Tomkins, D.J. [McMaster Univ., Hamilton (Canada); Allingham-Hawkins, D.J.; Buchwald, M. [Hospital Sick Children, Toronto, Ontario (Canada)

    1994-09-01

    Cells from all four Fanconi anemia complementation groups show hypersensitivity to cell-killing by mitomycin C (MMC), diepoxybutane (DEB) and other DNA cross-linking agents, and increased spontaneous and DEB-induced chromosome aberrations (CA). The extent of these phenotypes varies between lymphoblastoid cell lines from different complementation groups. Our data showed that the difference in MMC hypersensitivity and DEB-CA was not always coupled. While 230N (FA-B) had higher DEB-induced CA/cell than 536N (FA-C) (7.42 vs. 4.46 respectively), that latter was much more sensitive to cell-killing by MMC (dose at 10% survival, D{sub 10}: 5.2 vs. 1.2 ng/ml respectively). Strathdes et al. (1992) cloned a cDNA Fanconi anemia complementation group C (FACC) which complemented the hypersensitivity to MMC and DEB cell-killing of FA-C cells (536N) but not cells from the other three complementation groups. The present study was initiated to determine whether chromosome instability in 536N is also complemented by the FACC (FAC3) cDNA. The pREP4-FAC3 vector was transfected into 536N and transfectants selected with hygromycin B. The DEB D{sub 10} of 536N (1.0 {mu}M) was corrected to the control level (16.2 {mu}M for 3TO) by FACC (15.1 {mu}M for 536N-FACC), as previously demonstrated. Chromosome instability (cab, cse, ctb, cte) was determined without and with 0.1 {mu}g/ml DEB treatment. Spontaneous CA of 536N (0.30 aberrations/cell) was corrected to the control level (0.04 for 3TO) by FACC (0.06 for 536N-FACC). Similarly, the DEB-induced CA was corrected (2.74 for 536N vs. 0.06 and 0.02 for 3TO and 536N-FACC respectively). Thus, at least for FA complementation group C, hypersensitivity to cell-killing and chromosome instability are not dissociated and are most likely caused by the same gene defect.

  11. Hubungan antara Kualitas Air dengan Kebiasaan Makanan Ikan Batak (Tor douronensis) di Perairan Sungai Asahan Sumatera Utara

    OpenAIRE

    Lumbantoruan, Ria

    2015-01-01

    The study of water quality relationship and food habits of batak fish (Tor douronensis) in Asahan River North Sumatra was conducted. Aims of this research are to understand the water quality of Asahan River, the food habits of batak fish (Tor douronensis), and relationship between water quality and food habits of batak fish (Tor douronensis). Fish samples were caught by electrofishing and casnet and stomach content was analysis using volumetric method. Result showed that the batak fish (Tor d...

  12. The Paradox of Akt-mTOR Interactions

    Science.gov (United States)

    Vadlakonda, Lakshmipathi; Dash, Abhinandita; Pasupuleti, Mukesh; Anil Kumar, Kotha; Reddanna, Pallu

    2013-01-01

    The serine threonine protein kinase, Akt, is at the central hub of signaling pathways that regulates cell growth, differentiation, and survival. The reciprocal relation that exists between the two activating phosphorylation sites of Akt, T308 and S473, and the two mTOR complexes, C1 and C2, forms the central controlling hub that regulates these cellular functions. In our previous review “PI3Kinase (PI3K)-AKT-mTOR and Wnt signaling pathways in cell cycle” we discussed the reciprocal relation between mTORC1 and C2 complexes in regulating cell metabolism and cell cycle progression in cancer cells. We present in this article, a hypothesis that activation of Akt-T308 phosphorylation in the presence of high ATP:AMP ratio promotes the stability of its phosphorylations and activates mTORC1 and the energy consuming biosynthetic processes. Depletion of energy leads to inactivation of mTORC1, activation of AMPK, FoxO, and promotes constitution of mTORC2 that leads to phosphorylation of Akt S473. Akt can also be activated independent of PI3K; this appears to have an advantage under situations like dietary restrictions, where insulin/insulin growth factor signaling could be a casualty. PMID:23802099

  13. The paradox of Akt -mTOR interactions

    Directory of Open Access Journals (Sweden)

    LAKSHMIPATHI eVADLAKONDA

    2013-06-01

    Full Text Available The serine threonine (ser/thr protein kinase, Akt, is at the central hub of signaling pathways that regulates cell growth, differentiation and survival. The reciprocal relation that exists between the two activating phosphorylation sites of Akt, T308 and S473, and the two mTOR complexes, C1 and C2, forms the central controlling hub that regulates these cellular functions. In our previous review 'PI3K-AKT-mTOR and Wnt signaling pathways in cell cycle' we discussed the reciprocal relation between mTORC1 and C2 complexes in regulating cell metabolism and cell cycle progression in cancer cells. We present in this article, a hypothesis that activation of Akt T308 phosphorylation in the presence of high ATP: AMP ratio promotes the stability of its phosphorylations and activates mTORC1 and the energy consuming biosynthetic processes. Depletion of energy leads to inactivation of mTORC1, activation of AMPK, FoxO, and promotes constitution of mTORC2 that leads to phosphorylation of Akt S473. Akt can also be activated independent of PI3K; this appears to have an advantage under situations like dietary restrictions, where IIS could be a casualty.

  14. ARD1 Stabilization of TSC2 Suppresses Tumorigenesis Through the mTOR Signaling Pathway

    Science.gov (United States)

    Kuo, Hsu-Ping; Lee, Dung-Fang; Chen, Chun-Te; Liu, Mo; Chou, Chao-Kai; Lee, Hong-Jen; Du, Yi; Xie, Xiaoming; Wei, Yongkun; Xia, Weiya; Weihua, Zhang; Yang, Jer-Yen; Yen, Chia-Jui; Huang, Tzu-Hsuan; Tan, Minjia; Xing, Gang; Zhao, Yingming; Lin, Chien-Hsing; Tsai, Shih-Feng; Fidler, Isaiah J.; Hung, Mien-Chie

    2010-01-01

    Mammalian target of rapamycin (mTOR) regulates various cellular functions, including tumorigenesis, and is inhibited by the tuberous sclerosis 1 (TSC1)–TSC2 complex. Here, we demonstrate that arrest-defective protein 1 (ARD1) physically interacts with, acetylates, and stabilizes TSC2, thereby repressing mTOR activity. The inhibition of mTOR by ARD1 inhibits cell proliferation and increases autophagy, thereby inhibiting tumorigenicity. Correlation between ARD1 and TSC2 abundance was apparent in multiple tumor types. Moreover, evaluation of loss of heterozygosity at Xq28 revealed allelic loss in 31% of tested breast cancer cell lines and tumor samples. Together, our findings suggest that ARD1 functions as an inhibitor of the mTOR pathway and that dysregulation of the ARD1-TSC2-mTOR axis may contribute to cancer development. PMID:20145209

  15. Torsional Angle Driver (TorAD) System for HyperChem/Excel

    Science.gov (United States)

    Starkey, Ronald

    1999-02-01

    The torsional angle driver system for HyperChem/Excel is a package of several Excel spreadsheets and macro programs to be used with HyperChem to obtain and plot information, such as total energy, for the conformations that result from a 360° rotation about a torsional angle system in a molecule. The TorAD system also includes several HyperChem scripts to facilitate its use. TorAD was developed for use in the undergraduate organic chemistry laboratory. The results obtained with TorAD could be obtained manually with HyperChem, but it would take considerable time and would not be instructive to the students. Use of the TorAD system allows students to spend their time on the more important aspect of conformation analysisinterpretation of results. The Excel spreadsheet/macro programs in TorAD include: · Tor_xl_a and tor_xl obtain and plot the total energy at 5° torsional-angle intervals. The calculation method, the torsional-angle restraint, and the structure to be used at each angle can be set by the user. The advanced version, tor_xl_a, which requires HyperChem 4.5 or later, also allows torsional-angle structures to be saved for later recall as individual structures or, using a HyperChem script, in a movie format. It also provides a rapid scan of the 360° rotation where only single-point calculations, rather than geometry optimizations, are performed. The tor_xl system will perform routine tasks in a manner suitable for most instructional settings. · Tor_Comp performs molecular mechanics optimizations at 5° intervals and obtains and plots four energy parameters (total, torsional, nonbonded, and bond [bend plus stretch] energy) as a function of torsional angle. The calculation method and the restraint can be specified. · TorDipol produces a plot of the total energy and the calculated dipole moment at 5° steps of the torsional angle. The default calculation is the semi-empirical AM1 method, but other methods can be used. The calculation method and the restraint

  16. Tomato FK506 Binding Protein 12KD (FKBP12 mediates the interaction between rapamycin and Target of Rapamycin (TOR

    Directory of Open Access Journals (Sweden)

    Fangjie Xiong

    2016-11-01

    Full Text Available Target of Rapamycin (TOR signaling is an important regulator in multiple organisms including yeast, plants and animals. However, the TOR signaling in plants is much less understood as compared to that in yeast and animals. TOR kinase can be efficiently suppressed by rapamycin in the presence of functional FK506 Binding Protein 12KD (FKBP12 in yeast and animals. In most examined higher plants rapamycin fails to inhibit TOR kinase due to the non-functional FKBP12. Here we find that tomato plants showed obvious growth inhibition when treated with rapamycin and the inhibitory phenotype is similar to suppression of TOR causing by active-site TOR inhibitors (asTORis such as KU63794, AZD8055 and Torin1. The chemical genetic assays using TOR inhibitors and heterologous expressing SlFKBP12 in Arabidopsis indicated that the TOR signaling is functional in tomato. The protein gel shifting and TOR inhibitors combination assays showed that SlFKBP12 can mediate the interaction between rapamycin and TOR. Furthermore, comparative expression profiling analysis between treatments with rapamycin and KU63794 identified highly overlapped Differentially Expressed Genes (DEGs which are involved in many anabolic and catabolic processes, such as photosynthesis, cell wall restructuring, and senescence in tomato. These observations suggest that SlFFBP12 is functional in tomato. The results provided basic information of TOR signaling in tomato, and also some new insights into how TOR controls plant growth and development through reprogramming the transcription profiles

  17. A Legume TOR Protein Kinase Regulates Rhizobium Symbiosis and Is Essential for Infection and Nodule Development1[OPEN

    Science.gov (United States)

    Blanco, Lourdes; Quinto, Carmen

    2016-01-01

    The target of rapamycin (TOR) protein kinase regulates metabolism, growth, and life span in yeast, animals, and plants in coordination with nutrient status and environmental conditions. The nutrient-dependent nature of TOR functionality makes this kinase a putative regulator of symbiotic associations involving nutrient acquisition. However, TOR’s role in these processes remains to be understood. Here, we uncovered the role of TOR during the bean (Phaseolus vulgaris)-Rhizobium tropici (Rhizobium) symbiotic interaction. TOR was expressed in all tested bean tissues, with higher transcript levels in the root meristems and senesced nodules. We showed TOR promoter expression along the progressing infection thread and in the infected cells of mature nodules. Posttranscriptional gene silencing of TOR using RNA interference (RNAi) showed that this gene is involved in lateral root elongation and root cell organization and also alters the density, size, and number of root hairs. The suppression of TOR transcripts also affected infection thread progression and associated cortical cell divisions, resulting in a drastic reduction of nodule numbers. TOR-RNAi resulted in reduced reactive oxygen species accumulation and altered CyclinD1 and CyclinD3 expression, which are crucial factors for infection thread progression and nodule organogenesis. Enhanced expression of TOR-regulated ATG genes in TOR-RNAi roots suggested that TOR plays a role in the recognition of Rhizobium as a symbiont. Together, these data suggest that TOR plays a vital role in the establishment of root nodule symbiosis in the common bean. PMID:27698253

  18. The emerging role of m-TOR up-regulation in brain Astrocytoma.

    Science.gov (United States)

    Ryskalin, Larisa; Limanaqi, Fiona; Biagioni, Francesca; Frati, Alessandro; Esposito, Vincenzo; Calierno, Maria Teresa; Lenzi, Paola; Fornai, Francesco

    2017-05-01

    The present manuscript is an overview of various effects of mTOR up-regulation in astrocytoma with an emphasis on its deleterious effects on the proliferation of Glioblastoma Multiforme. The manuscript reports consistent evidence indicating the occurrence of mTOR up-regulation both in experimental and human astrocytoma. The grading of human astrocytoma is discussed in relationship with mTOR up-regulation. In the second part of the manuscript, the biochemical pathways under the influence of mTOR are translated to cell phenotypes which are generated by mTOR up-regulation and reverted by its inhibition. A special section is dedicated to the prominent role of autophagy in mediating the effects of mTOR in glioblastoma. In detail, autophagy inhibition produced by mTOR up-regulation determines the fate of cancer stem cells. On the other hand, biochemical findings disclose the remarkable effects of autophagy activators as powerful inducers of cell differentiation with a strong prevalence towards neuronal phenotypes. Thus, mTOR modulation acts on the neurobiology of glioblastoma just like it operates in vivo at the level of brain stem cell niches by altering autophagy-dependent cell differentiation. In the light of such a critical role of autophagy we analyzed the ubiquitin proteasome system. The merging between autophagy and proteasome generates a novel organelle, named autophagoproteasome which is strongly induced by mTOR inhibitors in glioblastoma cells. Remarkably, when mTOR is maximally inhibited the proteasome component selectively moves within autophagy vacuoles, thus making the proteasome activity dependent on the entry within autophagy compartment.

  19. Susceptibility to malignant hyperthermia

    NARCIS (Netherlands)

    Snoeck, Marcus Matheus Johannes

    2004-01-01

    In this thesis the author studied the diagnostic procedures for susceptibility to malignant hyperthermia (MH), with special emphasis upon refining the biological diagnostic test and improving protocols and guidelines for investigation of MH susceptibility. MH is a pharmacogenetic disease of skeletal

  20. Exposure to hydrocarbons 10 years after the Exxon Valdez oil spill: evidence from cytochrome P4501A expression and biliary FACs in nearshore demersal fishes.

    Science.gov (United States)

    Jewett, Stephen C; Dean, Thomas A; Woodin, Bruce R; Hoberg, Max K; Stegeman, John J

    2002-01-01

    Three biomarkers of hydrocarbon exposure, CYP1A in liver vascular endothelium, liver ethoxyresorufin O-deethylase (EROD), and biliary fluorescent aromatic compounds (FACs), were examined in the nearshore fishes, masked greenling (Hexagrammos octogrammus) and crescent gunnel (Pholis laeta), collected in Prince William Sound, Alaska, 7-10 years after the Exxon Valdez oil spill (EVOS). All biomarkers were elevated in fish collected from sites originally oiled, in comparison to fish from unoiled sites. In 1998, endothelial CYP1A in masked greenling from sites that were heavily oiled in 1989 was significantly higher than in fish collected outside the spill trajectory. In 1999, fishes collected from sites adjacent to intertidal mussel beds containing lingering Exxon Valdez oil had elevated endothelial CYP1A and EROD, and high concentrations of biliary FACs. Fishes from sites near unoiled mussel beds, but within the original spill trajectory, also showed evidence of hydrocarbon exposure, although there were no correlations between sediment petroleum hydrocarbon and any of the biomarkers. Our data show that 10 years after the spill, nearshore fishes within the original spill zone were still exposed to residual EVOS hydrocarbons.

  1. Knockdown of TOR causing ovarian diapause in a genetically stable brachypterous strain of Nilaparvata lugens.

    Science.gov (United States)

    Liu, Fangzhou; Li, Kaiyin; Cai, Wanlun; Zhao, Jing; Zou, Yulan; Hua, Hongxia

    2017-08-01

    Brown planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera: Delphacidae), is one of the most damaging pests of rice crops. BPH is a migratory insect with a delayed ovarian development in migrants classified as reproductive diapause. The molecular mechanism of reproductive diapause remains unclear, although we suspect it might be regulated by one or more nutrient signaling pathways. The target of rapamycin (TOR) pathway regulates cell growth in response to nutritional information, which raised a hypothesis that TOR mediates BPH reproductive diapause. We used a pure brachypterous strain (BS) and a predominantly macropterous strain (MS) to investigate the roles of NlTOR in BPH reproductive diapause. We found that NlTOR is expressed from the nymphal to adult stages, with a higher expression level of NlTOR in BS adults at 1, 2, and 4 days posteclosion than in MS at the same time points. Injection of dsNlTOR into BS nymphs resulted in the termination of BPH female ovary development and the retardation of nymph development. We infer that TOR signaling functions in BPH reproductive diapause by regulating the expression of NlFoxA and NlVitellogenin. © 2017 Wiley Periodicals, Inc.

  2. Distributed Performance Measurement and Usability Assessment of the Tor Anonymization Network

    Directory of Open Access Journals (Sweden)

    Steffen Kunz

    2012-05-01

    Full Text Available While the Internet increasingly permeates everyday life of individuals around the world, it becomes crucial to prevent unauthorized collection and abuse of personalized information. Internet anonymization software such as Tor is an important instrument to protect online privacy. However, due to the performance overhead caused by Tor, many Internet users refrain from using it. This causes a negative impact on the overall privacy provided by Tor, since it depends on the size of the user community and availability of shared resources. Detailed measurements about the performance of Tor are crucial for solving this issue. This paper presents comparative experiments on Tor latency and throughput for surfing to 500 popular websites from several locations around the world during the period of 28 days. Furthermore, we compare these measurements to critical latency thresholds gathered from web usability research, including our own user studies. Our results indicate that without massive future optimizations of Tor performance, it is unlikely that a larger part of Internet users would adopt it for everyday usage. This leads to fewer resources available to the Tor community than theoretically possible, and increases the exposure of privacy-concerned individuals. Furthermore, this could lead to an adoption barrier of similar privacy-enhancing technologies for a Future Internet.

  3. Stimulation of the creatine transporter SLC6A8 by the protein kinase mTOR.

    Science.gov (United States)

    Shojaiefard, Manzar; Christie, David L; Lang, Florian

    2006-03-24

    Cellular accumulation of creatine is accomplished by the Na(+), Cl(-), and creatine transporter CreaT (SLC6A8). The mammalian target of rapamycin (mTOR) is a kinase stimulating cellular nutrient uptake. The present experiments explored whether SLC6A8 is regulated by mTOR. In Xenopus oocytes expressing SLC6A8 but not in water injected oocytes, creatine-induced a current which was significantly enhanced by coexpression of mTOR. Kinetic analysis revealed that mTOR enhanced maximal current without significantly altering affinity. Preincubation of the oocytes for 32 h with rapamycin (50 nM) decreased the creatine-induced current and abrogated its stimulation by mTOR. The effect of mTOR on CreaT was blunted by additional coexpression of the inactive mutant of the serum and glucocorticoid-inducible kinase (K119N)SGK1 and mimicked by coexpression of wild type SGK1. In conclusion, mTOR stimulates the creatine transporter SLC6A8 through mechanisms at least partially shared by the serum and glucocorticoid-inducible kinase SGK1.

  4. Cap-independent translation ensures mTOR expression and function upon protein synthesis inhibition.

    Science.gov (United States)

    Marques-Ramos, Ana; Candeias, Marco M; Menezes, Juliane; Lacerda, Rafaela; Willcocks, Margaret; Teixeira, Alexandre; Locker, Nicolas; Romão, Luísa

    2017-11-01

    The mechanistic/mammalian target of rapamycin (mTOR) is a conserved serine/threonine kinase that integrates cellular signals from the nutrient and energy status to act, namely, on the protein synthesis machinery. While major advances have emerged regarding the regulators and effects of the mTOR signaling pathway, little is known about the regulation of mTOR gene expression. Here, we show that the human mTOR transcript can be translated in a cap-independent manner, and that its 5' untranslated region (UTR) is a highly folded RNA scaffold capable of binding directly to the 40S ribosomal subunit. We further demonstrate that mTOR is able to bypass the cap requirement for translation both in normal and hypoxic conditions. Moreover, our data reveal that the cap-independent translation of mTOR is necessary for its ability to induce cell-cycle progression into S phase. These results suggest a novel regulatory mechanism for mTOR gene expression that integrates the global protein synthesis changes induced by translational inhibitory conditions. © 2017 Marques-Ramos et al.; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  5. Empalamiento torácico con una barra de hierro

    Directory of Open Access Journals (Sweden)

    José Luis Aranda

    2008-07-01

    Full Text Available Varón de 19 años que, tras precipitación accidental, presenta doble empalamiento. Fue trasladado a nuestro servicio bajo ventilación mecánica, encontrándose hemodinámicamente estable. Presentaba empalamiento torácico por barra de hierro con orificio de entrada subescapular izquierdo (Fig. 1 y salida en fosa supraclavicular derecha (Fig. 2, junto a otro fragmento alojado en pala ilíaca izquierda. Trasladado a quirófano, se realizó toracotomía derecha para extracción de la barra bajo control visual directo, encontrándose pequeña laceración del segmento dos pulmonar que fue suturada, sin lesión vascular subclavia ni del plexo. La evolución postoperatoria fue satisfactoria, recibiendo el alta al tercer día postoperatorio.

  6. mTOR regulates phagosome and entotic vacuole fission.

    Science.gov (United States)

    Krajcovic, Matej; Krishna, Shefali; Akkari, Leila; Joyce, Johanna A; Overholtzer, Michael

    2013-12-01

    Macroendocytic vacuoles formed by phagocytosis, or the live-cell engulfment program entosis, undergo sequential steps of maturation, leading to the fusion of lysosomes that digest internalized cargo. After cargo digestion, nutrients must be exported to the cytosol, and vacuole membranes must be processed by mechanisms that remain poorly defined. Here we find that phagosomes and entotic vacuoles undergo a late maturation step characterized by fission, which redistributes vacuolar contents into lysosomal networks. Vacuole fission is regulated by the serine/threonine protein kinase mammalian target of rapamycin complex 1 (mTORC1), which localizes to vacuole membranes surrounding engulfed cells. Degrading engulfed cells supply engulfing cells with amino acids that are used in translation, and rescue cell survival and mTORC1 activity in starved macrophages and tumor cells. These data identify a late stage of phagocytosis and entosis that involves processing of large vacuoles by mTOR-regulated membrane fission.

  7. [Genomic variability of vibrio cholerae El Tor biovariant strains].

    Science.gov (United States)

    Smirnova, N I; Kostromitina, E A; Osin, A V; Kutyrev, V V

    2005-01-01

    The authors performed comparative analysis of the genomes of 145 clinical and environmental isolates of Vibrio cholerae El Tor biovariants using single locus and multiplex PCR. The study found that clinical strains isolated from patients with cholera formed a genetically homogenous group, where bacterial chromosome contained all the tested virulence genes, situated on mobile genetic elements that had been acquired by the pathogen at various stages of its evolution. Strains isolated from water ecosystems during interepidemic period were heterogeneous and formed three groups: a small number of virulent strains; non-toxigenic vibrio strains that, in the process of reductional variation in their new econiche, had only managed to maintain individual virulence genes; non-pathogenic "water" vibrios, whose chromosome contained only the genes from its core part, mobile genetic elements being optionally represented only by the persistence island. Molecular typing established genetic relations among V. cholerae strains under study.

  8. Idarubicin induces mTOR-dependent cytotoxic autophagy in leukemic cells

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, Biljana [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Bosnjak, Mihajlo [Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade (Serbia); Arsikin, Katarina [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Mircic, Aleksandar; Suzin-Zivkovic, Violeta [Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade (Serbia); Bogdanovic, Andrija [Clinic for Hematology, Clinical Centre of Serbia, School of Medicine, University of Belgrade, Belgrade (Serbia); Perovic, Vladimir [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Martinovic, Tamara; Kravic-Stevovic, Tamara; Bumbasirevic, Vladimir [Institute of Histology and Embryology, School of Medicine, University of Belgrade, Belgrade (Serbia); Trajkovic, Vladimir, E-mail: vtrajkovic@med.bg.ac.rs [Institute of Microbiology and Immunology, School of Medicine, University of Belgrade, Dr. Subotica 1, 11000 Belgrade (Serbia); Harhaji-Trajkovic, Ljubica, E-mail: buajk@yahoo.com [Institute for Biological Research, University of Belgrade, Belgrade, Despot Stefan Blvd. 142, 11000 Belgrade (Serbia)

    2014-08-01

    We investigated if the antileukemic drug idarubicin induces autophagy, a process of programmed cellular self-digestion, in leukemic cell lines and primary leukemic cells. Transmission electron microscopy and acridine orange staining demonstrated the presence of autophagic vesicles and intracellular acidification, respectively, in idarubicin-treated REH leukemic cell line. Idarubicin increased punctuation/aggregation of microtubule-associated light chain 3B (LC3B), enhanced the conversion of LC3B-I to autophagosome-associated LC3B-II in the presence of proteolysis inhibitors, and promoted the degradation of the selective autophagic target p62, thus indicating the increase in autophagic flux. Idarubicin inhibited the phosphorylation of the main autophagy repressor mammalian target of rapamycin (mTOR) and its downstream target p70S6 kinase. The treatment with the mTOR activator leucine prevented idarubicin-mediated autophagy induction. Idarubicin-induced mTOR repression was associated with the activation of the mTOR inhibitor AMP-activated protein kinase and down-regulation of the mTOR activator Akt. The suppression of autophagy by pharmacological inhibitors or LC3B and beclin-1 genetic knockdown rescued REH cells from idarubicin-mediated oxidative stress, mitochondrial depolarization, caspase activation and apoptotic DNA fragmentation. Idarubicin also caused mTOR inhibition and cytotoxic autophagy in K562 leukemic cell line and leukocytes from chronic myeloid leukemia patients, but not healthy controls. By demonstrating mTOR-dependent cytotoxic autophagy in idarubicin-treated leukemic cells, our results warrant caution when considering combining idarubicin with autophagy inhibitors in leukemia therapy. - Highlights: • Idarubicin induces autophagy in leukemic cell lines and primary leukemic cells. • Idarubicin induces autophagy by inhibiting mTOR in leukemic cells. • mTOR suppression by idarubicin is associated with AMPK activation and Akt blockade.

  9. Vibrio vulnificus induces mTOR activation and inflammatory responses in macrophages.

    Directory of Open Access Journals (Sweden)

    Dan-Li Xie

    Full Text Available Vibrio vulnificus (V. vulnificus, a Gram-negative marine bacterium, can cause life-threatening primary septicemia, especially in patients with liver diseases. How V. vulnificus affects the liver and how it acts on macrophages are not well understood. In this report, we demonstrated that V. vulnificus infection causes a strong inflammatory response, marked expansion of liver-resident macrophages, and liver damage in mice. We demonstrated further that V. vulnificus activates mTOR in macrophages and inhibition of mTOR differentially regulates V. vulnificus induced inflammatory responses, suggesting the possibility of targeting mTOR as a strategy to modulate V. vulnificus induced inflammatory responses.

  10. Epidemiología del traumatismo torácico grave

    OpenAIRE

    Cordero Lorenzana, María Lourdes

    2016-01-01

    [Resumen] Objetivo: Características del traumatismo torácico grave en UCI. Mortalidad. Material y método: Análisis descriptivo retrospectivo, univariado y regresión de 100 variables en 1174 pacientes con traumatismo torácico grave (1993-2010). Resultados: Más varones (4:1) de 43,5±18,9 años. 96,5% de traumatismos torácicos cerrados y 89% asociado. Lesiones óseas frecuentes: fracturas costales (71,2%) y claviculares (17,9%). Otras: contusión pulmonar (44%), hemotórax (41,7...

  11. A replication and methodological critique of the study "Evaluating drug trafficking on the Tor Network"

    National Research Council Canada - National Science Library

    Munksgaard, Rasmus; Demant, Jakob; Branwen, Gwern

    2016-01-01

    .... Dolliver's 2015 article "Evaluating drug trafficking on the Tor Network: Silk Road 2, the Sequel" addresses this theme by evaluating drug trafficking on one of the most well-known cryptomarkets, Silk Road 2.0...

  12. Enhanced Sensitivity of PTEN-Deficient Tumors to Inhibition of FRAP/mTOR

    National Research Council Canada - National Science Library

    Mehran S. Neshat; Ingo K. Mellinghoff; Chris Tran; Bangyan Stiles; George Thomas; Roseann Petersen; Philip Frost; James J. Gibbons; Hong Wu; Charles L. Sawyers

    2001-01-01

    Recent evidence places the FRAP/mTOR kinase downstream of the phosphatidyl inositol 3-kinase/Akt-signaling pathway, which is up-regulated in multiple cancers because of loss of the PTEN tumor suppressor gene...

  13. mTOR as a multifunctional therapeutic target in HIV infection

    DEFF Research Database (Denmark)

    Nicoletti, Ferdinando; Fagone, Paolo; Meroni, PierLuigi

    2011-01-01

    Patients undergoing long-term highly active antiretroviral therapy treatment are probably at a higher risk of various HIV-related complications. Hyperactivation of The mammalian target of rapamycin (mTOR) has been found to contribute to dysregulated apoptosis and autophagy which determine CD4(+)-T......-cell loss, impaired function of innate immunity and development of neurocognitive disorders. Dysregulated mTOR activation has also been shown to play a key part in the development of nephropathy and in the pathogenesis of HIV-associated malignancies. These studies strongly support a multifunctional key role...... for mTOR in the pathogenesis of HIV-related disorders and suggest that specific mTOR inhibitors could represent a novel approach for the prevention and treatment of these pathologies....

  14. Adapting the Stress Response: Viral Subversion of the mTOR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Valerie Le Sage

    2016-05-01

    Full Text Available The mammalian target of rapamycin (mTOR is a central regulator of gene expression, translation and various metabolic processes. Multiple extracellular (growth factors and intracellular (energy status molecular signals as well as a variety of stressors are integrated into the mTOR pathway. Viral infection is a significant stress that can activate, reduce or even suppress the mTOR signaling pathway. Consequently, viruses have evolved a plethora of different mechanisms to attack and co-opt the mTOR pathway in order to make the host cell a hospitable environment for replication. A more comprehensive knowledge of different viral interactions may provide fruitful targets for new antiviral drugs.

  15. Next-generation mTOR inhibitors in clinical oncology: how pathway complexity informs therapeutic strategy.

    LENUS (Irish Health Repository)

    Wander, Seth A

    2011-04-01

    Mammalian target of rapamycin (mTOR) is a PI3K-related kinase that regulates cell growth, proliferation, and survival via mTOR complex 1 (mTORC1) and mTORC2. The mTOR pathway is often aberrantly activated in cancers. While hypoxia, nutrient deprivation, and DNA damage restrain mTORC1 activity, multiple genetic events constitutively activate mTOR in cancers. Here we provide a brief overview of the signaling pathways up- and downstream of mTORC1 and -2, and discuss the insights into therapeutic anticancer targets - both those that have been tried in the clinic with limited success and those currently under clinical development - that knowledge of these pathways gives us.

  16. PREDICTION OF THE COURSE OF OSTEOARTHROSIS FROM mTOR (MAMMALIAN TARGET OF RAPAMYCIN GENE EXPRESSION

    Directory of Open Access Journals (Sweden)

    E V Chetina

    2012-01-01

    Results. Analysis of gene expression in the outpatients with OA identified two subgroups: in one subgroup (n = 13 mTOR expression was considerably much less than that in the control group; the expression of ATG1 and p21 did not differ greatly from the control and that of caspase 3 and TNF-α was significantly higher. The other outpatients (n = 20 and all the examined patients needing endoprosthetic replacement were ascertained to have a higher gene expression of mTOR, ATG1, p21, caspase 3, and TNF-α than in the control group. Before endoprosthetic replacement, severe joint destruction in patients with OA was associated with enhanced gene expression of mTOR, ATG1, p21, and caspase 3. Conclusion. In early-stage disease, increased mTOR gene expression may serve as a prognostic marker of the severity of the disease and articular cartilage destruction.

  17. Expression analysis of rare cellular subsets: direct RT-PCR on limited cell numbers obtained by FACS or soft agar assays.

    Science.gov (United States)

    Ho, Victor; Yeo, Shi Yun; Kunasegaran, Kamini; De Silva, Duvini; Tarulli, Gerard A; Voorhoeve, P Mathijs; Pietersen, Alexandra M

    2013-04-01

    Since tissues and tumors are heterogenous populations containing different cell types, their transcriptomes are blends of multiple mRNA expression profiles. Although fluorescence-activated cell sorting (FACS) allows isolation of individual cell types, RNA isolation and quantification remain problematic from rare subsets, such as tissue stem cells. Likewise, identification of transcriptional changes relevant to the tumorigenic potential of mammalian cells while they are actively growing as colonies in soft agar is also hampered by limited amounts of starting material. Here we describe a convenient method that fills the gap between single cell and whole tissue mRNA analysis, enabling mRNA quantification for individual colonies picked from soft agar. Our method involves direct lysis, reverse transcription and quantitative PCR (RT-qPCR) on 500 sorted cells or a single soft agar colony, thus allowing evaluation of up to 20 transcripts in functionally distinct subpopulations without the need for RNA isolation or amplification.

  18. Prototipo de simulador de tornado para el combate Aéreo No. 3 (CACOM 3 de la Fuerza Aérea Colombiana (FAC

    Directory of Open Access Journals (Sweden)

    Jorge Mario Cárdenas Cabrera

    2012-09-01

    El comando CACOM 3 de la Fuerza Aérea Colombiana (FAC ha tomado la iniciativa en este aspecto y se ha dado a la tarea de estudiar este fenómeno, trabajando en el diseño de un simulador de tornados a escala, con base en el ya existente, desarrollado por el phD. Harald Eddens, introdujo modificaciones que permitan, además de generar el fenómeno, medir y controlar a través de dispositivos electrónicos algunas variables ambientales. Estos dispositivos permitirán iniciar estudios desde el comando y servir de apoyo para labores de educación de la población vulnerable en cuanto a entender cómo se forma un tornado.

  19. Intersystem-crossing and phosphorescence rates in fac-Ir{sup III}(ppy){sub 3}: A theoretical study involving multi-reference configuration interaction wavefunctions

    Energy Technology Data Exchange (ETDEWEB)

    Kleinschmidt, Martin; Marian, Christel M., E-mail: Christel.Marian@hhu.de [Institute of Theoretical and Computational Chemistry, Heinrich-Heine-University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf (Germany); Wüllen, Christoph van [Fachbereich Chemie and Forschungszentrum OPTIMAS, Technical University of Kaiserslautern, Erwin-Schrödinger-Straße 52, 67663 Kaiserslautern (Germany)

    2015-03-07

    We have employed combined density functional theory and multi-reference configuration interaction methods including spin–orbit coupling (SOC) effects to investigate the photophysics of the green phosphorescent emitter fac-tris-(2-phenylpyridine)iridium (fac-Ir(ppy){sub 3}). A critical evaluation of our quantum chemical approaches shows that a perturbational treatment of SOC is the method of choice for computing the UV/Vis spectrum of this heavy transition metal complex while multi-reference spin–orbit configuration interaction is preferable for calculating the phosphorescence rates. The particular choice of the spin–orbit interaction operator is found to be of minor importance. Intersystem crossing (ISC) rates have been determined by Fourier transformation of the time correlation function of the transition including Dushinsky rotations. In the electronic ground state, fac-Ir(ppy){sub 3} is C{sub 3} symmetric. The calculated UV/Vis spectrum is in excellent agreement with experiment. The effect of SOC is particularly pronounced for the metal-to-ligand charge transfer (MLCT) band in the visible region of the absorption spectrum which does not only extend its spectral onset towards longer wavelengths but also experiences a blue shift of its maximum. Pseudo-Jahn-Teller interaction leads to asymmetric coordinate displacements in the lowest MLCT states. Substantial electronic SOC and a small energy gap make ISC an ultrafast process in fac-Ir(ppy){sub 3}. For the S{sub 1}↝T{sub 1} non-radiative transition, we compute a rate constant of k{sub ISC} = 6.9 × 10{sup 12} s{sup −1} which exceeds the rate constant of radiative decay to the electronic ground state by more than six orders of magnitude, in agreement with the experimental observation of a subpicosecond ISC process and a triplet quantum yield close to unity. As a consequence of the geometric distortion in the T{sub 1} state, the T{sub 1} → S{sub 0} transition densities are localized on one of the

  20. Proposal of an individual scientometric index with emphasis on ponderation of the effective contribution of the first author: h-fac índex.

    Science.gov (United States)

    Gregori Júnior, Francisco; Godoy, Moacir Fernandes de; Gregori, Francisco Ferreira

    2012-01-01

    In the individual assessment of a scientific performance, five scientometric indices have been used most: the h-index, the index g, the h-major index, the contemporary h-index and the normalized h-index. We propose an alternative index ("Index h-fac"), which considers positively the participation of the first author and that, by having a dynamic characteristic, continuously monitors his/her performance and is easily adaptable to particular or individual situations from different research groups. Results from the geometric mean between the original h-index as proposed by Hirsh and a correction factor ("fac", "first author commitment") and, in turn, this value is divided by the mean interval (in years) of all studies. The index emphasizes two scores (X and Y). These scores X and Y were obtained by asking to all 83 cardiovascular surgeons from Southern Brazil (Paraná, Santa Catarina and Rio Grande do Sul) and Specialists, how they realistically estimated, in percentage, their effective contribution in each published paper in which they appeared as first author. Of the total, 80 (96.4%) responded. The average obtained was 78.0% and on this basis, the X score was established as 0.75 and the score Y as 0.25. The new index also considers the total number of citations as first author and as co-author, the average number of coauthors per publication and the total number of papers published. Theoretical examples are presented, discussing the main advantages of application. Serial evaluations in real world situations should be instituted to confirm the diagnostic and prognostic utility of this new index.

  1. Effects of mTOR on neurological deficits after transient global ischemia

    Directory of Open Access Journals (Sweden)

    Xing Jihong

    2017-04-01

    Full Text Available Mammalian target of rapamycin (mTOR is a serine/threonine protein kinase and activation of its signal pathway plays an important role in regulating protein growth and synthesis as well as cell proliferation and survival. In the present study, we examined the contribution of mTOR and its downstream products to brain injuries and neurological deficiencies after cardiac arrest (CA induced-transient global ischemia. CA was induced by asphyxia followed by cardiopulmonary resuscitation (CPR in rats. Our results showed that expression of p-mTOR, mTOR-mediated phosphorylation of 4E-binding protein 4 (4E-BP1 and p70 ribosomal S6 protein kinase 1 (S6K1 pathways were amplified in CA rats compared to their controls. Blocking mTOR using rapamycin attenuated upregulation of pro-inflammatory cytokines (namely IL-1β, IL-6 and TNF-α, and Caspase-3, indicating cell apoptosis and also promoting the levels of vascular endothelial growth factor (VEGF and its subtype receptor VEGFR-2 in the hippocampus. Moreover, the effects of rapamycin were linked to improvement of neurological deficits and increased brain water content observed in CA rats. In conclusion, activation of mTOR signal is engaged in pathophysiological process during CA-induced transient global ischemia and blocking mTOR pathway plays a beneficial role in regulating injured neuronal tissues and neurological deficits via PIC, apoptotic Caspase-3 and VEGF mechanisms. Targeting one or more of these specific mTOR pathways and its downstream signaling molecules may present new opportunities for neural dysfunction and vulnerability related to transient global ischemia.

  2. Conservation, duplication, and loss of the Tor signaling pathway in the fungal kingdom

    Directory of Open Access Journals (Sweden)

    Heitman Joseph

    2010-09-01

    Full Text Available Abstract Background The nutrient-sensing Tor pathway governs cell growth and is conserved in nearly all eukaryotic organisms from unicellular yeasts to multicellular organisms, including humans. Tor is the target of the immunosuppressive drug rapamycin, which in complex with the prolyl isomerase FKBP12 inhibits Tor functions. Rapamycin is a gold standard drug for organ transplant recipients that was approved by the FDA in 1999 and is finding additional clinical indications as a chemotherapeutic and antiproliferative agent. Capitalizing on the plethora of recently sequenced genomes we have conducted comparative genomic studies to annotate the Tor pathway throughout the fungal kingdom and related unicellular opisthokonts, including Monosiga brevicollis, Salpingoeca rosetta, and Capsaspora owczarzaki. Results Interestingly, the Tor signaling cascade is absent in three microsporidian species with available genome sequences, the only known instance of a eukaryotic group lacking this conserved pathway. The microsporidia are obligate intracellular pathogens with highly reduced genomes, and we hypothesize that they lost the Tor pathway as they adapted and streamlined their genomes for intracellular growth in a nutrient-rich environment. Two TOR paralogs are present in several fungal species as a result of either a whole genome duplication or independent gene/segmental duplication events. One such event was identified in the amphibian pathogen Batrachochytrium dendrobatidis, a chytrid responsible for worldwide global amphibian declines and extinctions. Conclusions The repeated independent duplications of the TOR gene in the fungal kingdom might reflect selective pressure acting upon this kinase that populates two proteinaceous complexes with different cellular roles. These comparative genomic analyses illustrate the evolutionary trajectory of a central nutrient-sensing cascade that enables diverse eukaryotic organisms to respond to their natural

  3. mTOR regulates tau phosphorylation and degradation: implications for Alzheimer's disease and other tauopathies.

    Science.gov (United States)

    Caccamo, Antonella; Magrì, Andrea; Medina, David X; Wisely, Elena V; López-Aranda, Manuel F; Silva, Alcino J; Oddo, Salvatore

    2013-06-01

    Accumulation of tau is a critical event in several neurodegenerative disorders, collectively known as tauopathies, which include Alzheimer's disease and frontotemporal dementia. Pathological tau is hyperphosphorylated and aggregates to form neurofibrillary tangles. The molecular mechanisms leading to tau accumulation remain unclear and more needs to be done to elucidate them. Age is a major risk factor for all tauopathies, suggesting that molecular changes contributing to the aging process may facilitate tau accumulation and represent common mechanisms across different tauopathies. Here, we use multiple animal models and complementary genetic and pharmacological approaches to show that the mammalian target of rapamycin (mTOR) regulates tau phosphorylation and degradation. Specifically, we show that genetically increasing mTOR activity elevates endogenous mouse tau levels and phosphorylation. Complementary to it, we further demonstrate that pharmacologically reducing mTOR signaling with rapamycin ameliorates tau pathology and the associated behavioral deficits in a mouse model overexpressing mutant human tau. Mechanistically, we provide compelling evidence that the association between mTOR and tau is linked to GSK3β and autophagy function. In summary, we show that increasing mTOR signaling facilitates tau pathology, while reducing mTOR signaling ameliorates tau pathology. Given the overwhelming evidence that reducing mTOR signaling increases lifespan and healthspan, the data presented here have profound clinical implications for aging and tauopathies and provide the molecular basis for how aging may contribute to tau pathology. Additionally, these results provide preclinical data indicating that reducing mTOR signaling may be a valid therapeutic approach for tauopathies. © 2013 John Wiley & Sons Ltd and the Anatomical Society.

  4. Finding a better drug for epilepsy: The mTOR pathway as an antiepileptogenic target

    OpenAIRE

    Galanopoulou, Aristea S.; Gorter, Jan A.; Cepeda, Carlos

    2012-01-01

    The mTOR signaling pathway regulates cell growth, differentiation, proliferation and metabolism. Loss of function mutations in upstream regulators of mTOR have been highly associated with dysplasias, epilepsy and neurodevelopmental disorders. These include tuberous sclerosis, which is due to mutations in TSC1 or TSC2 genes, mutations in phosphatase and tensin homolog (PTEN) as in Cowden syndrome, polyhydramnios, megalencephaly, symptomatic epilepsy syndrome (PMSE) due to mutations in the STE2...

  5. Mammalian target of rapamycin (mTor) mediates tau protein dyshomeostasis: implication for Alzheimer disease.

    Science.gov (United States)

    Tang, Zhi; Bereczki, Erika; Zhang, Haiyan; Wang, Shan; Li, Chunxia; Ji, Xinying; Branca, Rui M; Lehtiö, Janne; Guan, Zhizhong; Filipcik, Peter; Xu, Shaohua; Winblad, Bengt; Pei, Jin-Jing

    2013-05-31

    Previous evidence from post-mortem Alzheimer disease (AD) brains and drug (especially rapamycin)-oriented in vitro and in vivo models implicated an aberrant accumulation of the mammalian target of rapamycin (mTor) in tangle-bearing neurons in AD brains and its role in the formation of abnormally hyperphosphorylated tau. Compelling evidence indicated that the sequential molecular events such as the synthesis and phosphorylation of tau can be regulated through p70 S6 kinase, the well characterized immediate downstream target of mTor. In the present study, we further identified that the active form of mTor per se accumulates in tangle-bearing neurons, particularly those at early stages in AD brains. By using mass spectrometry and Western blotting, we identified three phosphoepitopes of tau directly phosphorylated by mTor. We have developed a variety of stable cell lines with genetic modification of mTor activity using SH-SY5Y neuroblastoma cells as background. In these cellular systems, we not only confirmed the tau phosphorylation sites found in vitro but also found that mTor mediates the synthesis and aggregation of tau, resulting in compromised microtubule stability. Changes of mTor activity cause fluctuation of the level of a battery of tau kinases such as protein kinase A, v-Akt murine thymoma viral oncogene homolog-1, glycogen synthase kinase 3β, cyclin-dependent kinase 5, and tau protein phosphatase 2A. These results implicate mTor in promoting an imbalance of tau homeostasis, a condition required for neurons to maintain physiological function.

  6. PI3K/AKT/mTOR pathway in Angiogenesis

    Directory of Open Access Journals (Sweden)

    Jayashree eKarar

    2011-12-01

    Full Text Available The phosphatidylinositol 3-kinase (PI3K/AKT/mTOR pathway is activated in the majority of human cancers. This pathway is known to play a key role in numerous cellular functions including proliferation, adhesion, migration, invasion, metabolism, and survival, but in the current review we focus on its role in angiogenesis. PI3K activation may occur via RAS mutation, loss of PTEN, or by increased expression of growth factor receptors such as EGFR. There is a connection between the PI3K pathway and angiogenesis. Hypoxia leads to HIF-1α stabilization and is a major stimulus for increased VEGF production by tumor cells. However, activation of the PI3K/AKT pathway in tumor cells can also increase VEGF secretion, both by HIF-1 dependent and independent mechanisms. The PI3K/AKT pathway also modulates the expression of other angiogenic factors such as nitric oxide and angiopoietins. Numerous inhibitors targeting the PI3K/AKT/mTOR pathway have been developed, and these agents have been shown to decrease VEGF secretion and angiogenesis. The effect of these inhibitors on tumor vasculature can be difficult to predict. The vasculature of tumors is aberrant, leading to sluggish bloodflow and elevated interstitial blood pressure, which can be perpetuated by the high levels of VEGF. Hence, decreasing VEGF expression can paradoxically lead to vascular normalization and improved bloodflow in some tumors. In addition to its importance in cancer, the PI3K pathway also plays an essential role in the formation of normal blood vessels during development. Embryos with kinase-dead p110α catalytic subunit of PI3K develop vascular defects. Simulation of endothelial cells by VEGF leads to activation of the PI3K pathway within these cells, which is important for cell migration. Sustained endothelia1 activation of AKTl has been shown to induce the formation of structurally abnormal blood vessels that recapitulate the aberrations of tumor vessels. Hence, the PI3K pathway plays

  7. Discovery and Development of ATP-Competitive mTOR Inhibitors Using Computational Approaches.

    Science.gov (United States)

    Luo, Yao; Wang, Ling

    2017-11-16

    The mammalian target of rapamycin (mTOR) is a central controller of cell growth, proliferation, metabolism, and angiogenesis. This protein is an attractive target for new anticancer drug development. Significant progress has been made in hit discovery, lead optimization, drug candidate development and determination of the three-dimensional (3D) structure of mTOR. Computational methods have been applied to accelerate the discovery and development of mTOR inhibitors helping to model the structure of mTOR, screen compound databases, uncover structure-activity relationship (SAR) and optimize the hits, mine the privileged fragments and design focused libraries. Besides, computational approaches were also applied to study protein-ligand interactions mechanisms and in natural product-driven drug discovery. Herein, we survey the most recent progress on the application of computational approaches to advance the discovery and development of compounds targeting mTOR. Future directions in the discovery of new mTOR inhibitors using computational methods are also discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. The Role of mTOR Inhibitors for the Treatment of B-Cell Lymphomas

    Directory of Open Access Journals (Sweden)

    Pinelopi Argyriou

    2012-01-01

    Full Text Available Despite the fact that the majority of lymphomas initially respond to treatment, many patients relapse and die from disease that is refractory to current regimens. The need for new treatment strategies in lymphomas has led to the investigation and evaluation of novel agents that target cellular pathways. The mammalian target of rapamycin (mTOR is a representative pathway that may be implicated in lymphomagenesis. Rapamycin and especially its derivatives (temsirolimus, everolimus, and deforolimus represent the first described mTOR inhibitors. These agents have shown promising results in the treatment of lymphoid malignancies. On the other hand, new ATP-competitive mTOR inhibitors that provoke a broader inhibition of mTOR activity are in early stages of clinical development. The purpose of this paper is to summarize the existing knowledge about mTOR inhibitors and their use in the treatment of B-cell lymphomas. Relevant issues regarding mTOR biology in general as well as in B-cell lymphoid neoplasms are also discussed in short.

  9. Blocking mTOR Signalling with Rapamycin Ameliorates Imiquimod-induced Psoriasis in Mice.

    Science.gov (United States)

    Bürger, Claudia; Shirsath, Nitesh; Lang, Victoria; Diehl, Sandra; Kaufmann, Roland; Weigert, Andreas; Han, Ying-Ying; Ringel, Christian; Wolf, Peter

    2017-10-02

    The mTOR (mechanistic target of rapamycin) inhibitor rapamycin has long been known for its immune suppressive properties, but it has shown limited therapeutic success when given systemically to patients with psoriasis. Recent data have shown that the mTOR pathway is hyperactivated in lesional psoriatic skin, which probably contributes to the disease by interfering with maturation of keratinocytes. This study investigated the effect of topical rapamycin treatment in an imiquimod-induced psoriatic mouse model. The disease was less severe if the mice had received rapamycin treatment. Immunohistological analysis revealed that rapamycin not only prevented the activation of mTOR signalling (P-mTOR and P-S6 levels), but almost normalized the expression of epidermal differentiation markers. In addition, the influx of innate immune cells into the draining lymph nodes was partially reduced by rapamycin treatment. These data emphasize the role of mTOR signalling in the pathogenesis of psoriasis, and support the investigation of topical mTOR inhibition as a novel anti-psoriatic strategy.

  10. The Role of Mammalian Target of Rapamycin (mTOR in Insulin Signaling

    Directory of Open Access Journals (Sweden)

    Mee-Sup Yoon

    2017-10-01

    Full Text Available The mammalian target of rapamycin (mTOR is a serine/threonine kinase that controls a wide spectrum of cellular processes, including cell growth, differentiation, and metabolism. mTOR forms two distinct multiprotein complexes known as mTOR complex 1 (mTORC1 and mTOR complex 2 (mTORC2, which are characterized by the presence of raptor and rictor, respectively. mTOR controls insulin signaling by regulating several downstream components such as growth factor receptor-bound protein 10 (Grb10, insulin receptor substrate (IRS-1, F-box/WD repeat-containing protein 8 (Fbw8, and insulin like growth factor 1 receptor/insulin receptor (IGF-IR/IR. In addition, mTORC1 and mTORC2 regulate each other through a feedback loop to control cell growth. This review outlines the current understanding of mTOR regulation in insulin signaling in the context of whole body metabolism.

  11. Targeting tumorigenesis: development and use of mTOR inhibitors in cancer therapy

    Directory of Open Access Journals (Sweden)

    Kay Andrea

    2009-10-01

    Full Text Available Abstract The mammalian target of rapamycin (mTOR is an intracellular serine/threonine protein kinase positioned at a central point in a variety of cellular signaling cascades. The established involvement of mTOR activity in the cellular processes that contribute to the development and progression of cancer has identified mTOR as a major link in tumorigenesis. Consequently, inhibitors of mTOR, including temsirolimus, everolimus, and ridaforolimus (formerly deforolimus have been developed and assessed for their safety and efficacy in patients with cancer. Temsirolimus is an intravenously administered agent approved by the US Food and Drug Administration (FDA and the European Medicines Agency (EMEA for the treatment of advanced renal cell carcinoma (RCC. Everolimus is an oral agent that has recently obtained US FDA and EMEA approval for the treatment of advanced RCC after failure of treatment with sunitinib or sorafenib. Ridaforolimus is not yet approved for any indication. The use of mTOR inhibitors, either alone or in combination with other anticancer agents, has the potential to provide anticancer activity in numerous tumor types. Cancer types in which these agents are under evaluation include neuroendocrine tumors, breast cancer, leukemia, lymphoma, hepatocellular carcinoma, gastric cancer, pancreatic cancer, sarcoma, endometrial cancer, and non-small-cell lung cancer. The results of ongoing clinical trials with mTOR inhibitors, as single agents and in combination regimens, will better define their activity in cancer.

  12. The TOR Pathway Modulates the Structure of Cell Walls in Arabidopsis[W

    Science.gov (United States)

    Leiber, Ruth-Maria; John, Florian; Verhertbruggen, Yves; Diet, Anouck; Knox, J. Paul; Ringli, Christoph

    2010-01-01

    Plant cell growth is limited by the extension of cell walls, which requires both the synthesis and rearrangement of cell wall components in a controlled fashion. The target of rapamycin (TOR) pathway is a major regulator of cell growth in eukaryotes, and inhibition of this pathway by rapamycin reduces cell growth. Here, we show that in plants, the TOR pathway affects cell wall structures. LRR-extensin1 (LRX1) of Arabidopsis thaliana is an extracellular protein involved in cell wall formation in root hairs, and lrx1 mutants develop aberrant root hairs. rol5 (for repressor of lrx1) was identified as a suppressor of lrx1. The functionally similar ROL5 homolog in yeast, Ncs6p (needs Cla4 to survive 6), was previously found to affect TOR signaling. Inhibition of TOR signaling by rapamycin led to suppression of the lrx1 mutant phenotype and caused specific changes to galactan/rhamnogalacturonan-I and arabinogalactan protein components of cell walls that were similar to those observed in the rol5 mutant. The ROL5 protein accumulates in mitochondria, a target of the TOR pathway and major source of reactive oxygen species (ROS), and rol5 mutants show an altered response to ROS. This suggests that ROL5 might function as a mitochondrial component of the TOR pathway that influences the plant's response to ROS. PMID:20530756

  13. The TOR pathway modulates the structure of cell walls in Arabidopsis.

    Science.gov (United States)

    Leiber, Ruth-Maria; John, Florian; Verhertbruggen, Yves; Diet, Anouck; Knox, J Paul; Ringli, Christoph

    2010-06-01

    Plant cell growth is limited by the extension of cell walls, which requires both the synthesis and rearrangement of cell wall components in a controlled fashion. The target of rapamycin (TOR) pathway is a major regulator of cell growth in eukaryotes, and inhibition of this pathway by rapamycin reduces cell growth. Here, we show that in plants, the TOR pathway affects cell wall structures. LRR-extensin1 (LRX1) of Arabidopsis thaliana is an extracellular protein involved in cell wall formation in root hairs, and lrx1 mutants develop aberrant root hairs. rol5 (for repressor of lrx1) was identified as a suppressor of lrx1. The functionally similar ROL5 homolog in yeast, Ncs6p (needs Cla4 to survive 6), was previously found to affect TOR signaling. Inhibition of TOR signaling by rapamycin led to suppression of the lrx1 mutant phenotype and caused specific changes to galactan/rhamnogalacturonan-I and arabinogalactan protein components of cell walls that were similar to those observed in the rol5 mutant. The ROL5 protein accumulates in mitochondria, a target of the TOR pathway and major source of reactive oxygen species (ROS), and rol5 mutants show an altered response to ROS. This suggests that ROL5 might function as a mitochondrial component of the TOR pathway that influences the plant's response to ROS.

  14. Tratamiento endovascular de la aorta torácica descendente. Tratamiento endovascular de la aorta torácica descendente.

    Directory of Open Access Journals (Sweden)

    Hernán G. Bertoni

    2007-01-01

    Full Text Available ObjetivoEl propósito de esta publicación es comunicar nuestros resultados inmediatos y a mediano plazo del tratamiento endovascular de la aorta torácica descendente mediante implante de endoprótesis.Material y métodosEntre agosto de 1999 y agosto de 2006, 74 pacientes consecutivos, 53 hombres y 21 mujeres, fueron tratados por vía endovascular con implante de una prótesis autoexpandible. La edad media fue de 60 ± 14,8 años. Las indicaciones para tratamiento fueron disección aguda (n = 8; 11%, disección crónica (n = 31; 42%, hematoma intramural (n = 5; 7%, aneurisma verdadero (n = 17; 23%, úlcerapenetrante (n = 4; 5% y seudoaneurisma traumático (n = 9; 12%.ResultadosEl implante del dispositivo fue exitoso en 73 (98,6% pacientes; no se requirió conversión quirúrgica en ninguno de ellos. Ningún paciente presentó paraplejía o déficit neurológico. La mortalidad a los 30 días fue del 8,1% (n = 6. La mediana de seguimiento fue de 33,5 meses (rango 1-79 y la sobrevida global fue del 84% (IC 69-92% y del 91% (IC 77-97%, según se incluyese o no la mortalidad temprana. El 93% (IC 84-97% de los pacientes estaban libres de complicaciones relacionadas con el procedimiento. La mayoría de las complicaciones ocurrieron durante el primer año de seguimiento.ConclusionesEl tratamiento endovascular de la aorta torácica descendente con implante de endoprótesis autoexpandible es factible y seguro. La baja incidencia de eventos en relación con las series quirúrgicas publicadas hace que este procedimiento sea de elección en pacientes seleccionados.

  15. mTOR signaling and its involvement in the regulation of cell movements through remodeling the cytoskeleton architecture

    Directory of Open Access Journals (Sweden)

    Kosach V. R.

    2015-02-01

    Full Text Available mTOR kinase is one of the basic links at the crossroad of several signal transduction pathways. De­re­gulated mTOR kinase signaling accompanies the progress of cancer, diabetes, neurodegenerative disorders and aging. Implication of mTOR inhibitor rapamycin decreases migration and invasion of malignant cells, and metastasis formation. However, a precise mechanism of the regulation of cellular locomotion by mTOR kinase is not fully understood. This article focuses on the recent findings that demonstrated a possible role of mTOR kinase in the regulation of cytoskeleton remodeling and cell migration properties. Detailed studies on this non-canonical mTOR function will extend our knowledge about cell migration and metastasis formation and might improve anti-cancer therapeutic approaches.

  16. Genetic and pharmacologic evidence that mTOR targeting outweighs mTORC1 inhibition as an antimyeloma strategy.

    Science.gov (United States)

    Chen, Xi; Díaz-Rodríguez, Elena; Ocio, Enrique M; Paiva, Bruno; Mortensen, Deborah S; Lopez-Girona, Antonia; Chopra, Rajesh; Miguel, Jesús San; Pandiella, Atanasio

    2014-02-01

    The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates cell growth, proliferation, metabolism, and cell survival, and plays those roles by forming two functionally distinct multiprotein complexes: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Deregulation of the mTOR pathway has been found in different cancers, including multiple myeloma. Agents acting on mTORC1, such as rapamycin and derivatives, are being explored as antitumoral strategies. However, whether targeting mTOR would be a more effective antimyeloma strategy than exclusively acting on the mTORC1 branch remains to be established. In this report, we explored the activation status of mTOR routes in malignant plasma cells, and analyzed the contribution of mTOR and its two signaling branches to the proliferation of myeloma cells. Gene expression profiling demonstrated deregulation of mTOR pathway-related genes in myeloma plasma cells from patients. Activation of the mTOR pathway in myelomatous plasma cells was corroborated by flow cytometric analyses. RNA interference (RNAi) experiments indicated that mTORC1 predominated over mTORC2 in the control of myeloma cell proliferation. However, mTOR knockdown had a superior antiproliferative effect than acting only on mTORC1 or mTORC2. Pharmacologic studies corroborated that the neutralization of mTOR has a stronger antimyeloma effect than the individual inhibition of mTORC1 or mTORC2. Together, our data support the clinical development of agents that widely target mTOR, instead of agents, such as rapamycin or its derivatives, that solely act on mTORC1.

  17. One Bad Apple Spoils the Bunch: Exploiting P2P Applications to Trace and Profile Tor Users

    OpenAIRE

    Le Blond, Stevens; Manils, Pere; Abdelberi, Chaabane; Kaafar, Mohamed Ali; Castelluccia, Claude; Legout, Arnaud; Dabbous, Walid

    2011-01-01

    International audience; Tor is a popular low-latency anonymity network. However, Tor does not protect against the exploitation of an insecure application to reveal the IP address of, or trace, a TCP stream. In addition, because of the linkability of Tor streams sent together over a single circuit, tracing one stream sent over a circuit traces them all. Surprisingly, it is unknown whether this linkability allows in practice to trace a significant number of streams originating from secure (i.e....

  18. Take-over again: Investigating multimodal and directional TORs to get the driver back into the loop.

    Science.gov (United States)

    Petermeijer, Sebastiaan; Bazilinskyy, Pavlo; Bengler, Klaus; de Winter, Joost

    2017-07-01

    When a highly automated car reaches its operational limits, it needs to provide a take-over request (TOR) in order for the driver to resume control. The aim of this simulator-based study was to investigate the effects of TOR modality and left/right directionality on drivers' steering behaviour when facing a head-on collision without having received specific instructions regarding the directional nature of the TORs. Twenty-four participants drove three sessions in a highly automated car, each session with a different TOR modality (auditory, vibrotactile, and auditory-vibrotactile). Six TORs were provided per session, warning the participants about a stationary vehicle that had to be avoided by changing lane left or right. Two TORs were issued from the left, two from the right, and two from both the left and the right (i.e., nondirectional). The auditory stimuli were presented via speakers in the simulator (left, right, or both), and the vibrotactile stimuli via a tactile seat (with tactors activated at the left side, right side, or both). The results showed that the multimodal TORs yielded statistically significantly faster steer-touch times than the unimodal vibrotactile TOR, while no statistically significant differences were observed for brake times and lane change times. The unimodal auditory TOR yielded relatively low self-reported usefulness and satisfaction ratings. Almost all drivers overtook the stationary vehicle on the left regardless of the directionality of the TOR, and a post-experiment questionnaire revealed that most participants had not realized that some of the TORs were directional. We conclude that between the three TOR modalities tested, the multimodal approach is preferred. Moreover, our results show that directional auditory and vibrotactile stimuli do not evoke a directional response in uninstructed drivers. More salient and semantically congruent cues, as well as explicit instructions, may be needed to guide a driver into a specific

  19. The role of phospholipase D and phosphatidic acid in the mechanical activation of mTOR signaling in skeletal muscle.

    Science.gov (United States)

    Hornberger, T A; Chu, W K; Mak, Y W; Hsiung, J W; Huang, S A; Chien, S

    2006-03-21

    Signaling by the mammalian target of rapamycin (mTOR) has been reported to be necessary for mechanical load-induced growth of skeletal muscle. The mechanisms involved in the mechanical activation of mTOR signaling are not known, but several studies indicate that a unique [phosphotidylinositol-3-kinase (PI3K)- and nutrient-independent] mechanism is involved. In this study, we have demonstrated that a regulatory pathway for mTOR signaling that involves phospholipase D (PLD) and the lipid second messenger phosphatidic acid (PA) plays a critical role in the mechanical activation of mTOR signaling. First, an elevation in PA concentration was sufficient for the activation of mTOR signaling. Second, the isozymes of PLD (PLD1 and PLD2) are localized to the z-band in skeletal muscle (a critical site of mechanical force transmission). Third, mechanical stimulation of skeletal muscle with intermittent passive stretch ex vivo induced PLD activation, PA accumulation, and mTOR signaling. Finally, pharmacological inhibition of PLD blocked the mechanically induced increase in PA and the activation of mTOR signaling. Combined, these results indicate that mechanical stimuli activate mTOR signaling through a PLD-dependent increase in PA. Furthermore, we showed that mTOR signaling was partially resistant to rapamycin in muscles subjected to mechanical stimulation. Because rapamycin and PA compete for binding to the FRB domain on mTOR, these results suggest that mechanical stimuli activate mTOR signaling through an enhanced binding of PA to the FRB domain on mTOR.

  20. Comparative studies of S-bridged complexes of {sup 99m}Tc with fac(S)-[M(aet){sub 3}] (M = Rh{sup III}, Ir{sup III}; aet = 2-aminoethanethiolate)

    Energy Technology Data Exchange (ETDEWEB)

    Amir, N.; Roohi, S.; Mushtaq, A.; Pervez, S. [Isotope Production Div., Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan); Saeed, S. [Dept. of Medical Sciences, Pakistan Inst. of Engineering and Applied Sciences, Nilore, Islamabad (Pakistan)

    2009-09-15

    fac(S)-[Ir(aet){sub 3}] (aet = 2-aminoethanethiolate) is N3S3 metalloligand, which forms S-bridged polynuclear complexes with transition metal ions. A complex analogous to [Re{l_brace}Ir(aet{sub 3}){r_brace}{sub 2}]{sup 3+} was formed by the reaction of {sup 99m}TcO{sub 4}Na and fac(S)-[Ir(aet){sub 3}] in the presence of SnCl{sub 2}2H{sub 2}O. A simple method for radiollabelling of fac(S)-[Ir(aet){sub 3}] with {sup 99m}Tc was developed with radiolabelling efficiency higher than 99%. Effects of SnCl{sub 2} . 2H{sub 2}O concentration, time and pH on the radiolabelling efficiency were determined and compared with {sup 99m}Tc-[Rh(aet){sub 3}]. {sup 99m}Tc-[Ir(aet){sub 3}] was also characterized by electrophoresis, HPLC, biodistribution studies in rats and scintigraphy in rabbit. Higher uptake by kidneys showed rapid distribution of the labelled fac(S)-[Ir(aet){sub 3}]. Scintigrams show that liver, bladder and skeletal uptake were significant. The results of biodistribution showed that {sup 99m}Tc-[Ir(aet){sub 3}] uptake is quite rapid as compared to {sup 99m}Tc-[Rh(aet){sub 3}]. (orig.)

  1. Genetic susceptibility of periodontitis

    NARCIS (Netherlands)

    Laine, M.L.; Crielaard, W.; Loos, B.G.

    2012-01-01

    In this systematic review, we explore and summarize the peer-reviewed literature on putative genetic risk factors for susceptibility to aggressive and chronic periodontitis. A comprehensive literature search on the PubMed database was performed using the keywords ‘periodontitis’ or ‘periodontal

  2. Fourie susceptible.pmd

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    a number of cultivars exhibited field resistance to halo blight and bacterial brown spot, all cultivars were more or less susceptible to .... Cerillos. Alubia. I. 91. 57. Kranskop. Red speckled sugar. II. 97. 63. OPS-RS1. Red speckled sugar. II. 96. 63. OPS-RS2. Red speckled sugar. I. 100. 61. OPS-RS3. Red speckled sugar. II. 97.

  3. Correlation between telomerase and mTOR pathway in cancer stem cells.

    Science.gov (United States)

    Dogan, Fatma; Biray Avci, Cigir

    2018-01-30

    Cancer stem cells (CSCs), which are defined as a subset of tumor cells, are able to self-renew, proliferate, differentiate similar to normal stem cells. Therefore, targeting CSCs has been considered as a new approach in cancer therapy. The mammalian target of rapamycin (mTOR) is a receptor tyrosine kinase which plays an important role in regulating cell proliferation, differentiation, cell growth, self-renewal in CSCs. On the other hand, hTERT overactivation provides replicative feature and immortality to CSCs, so the stemness and replicative properties of CSCs depend on telomerase activity. Therefore hTERT/telomerase activity may become a universal biomarker for anticancer therapy and it is an attractive therapeutic target for CSCs. It is known that mTOR regulates telomerase activity at the translational and post-translational level. Researchers show that mTOR inhibitor rapamycin reduces telomerase activity without changing hTERT mRNA activity. Correlation between mTOR and hTERT is important for survival and immortality of cancer cells. In addition, the PI3K/AKT/mTOR signaling pathway and hTERT up-regulation are related with cancer stemness features and drug resistance. mTOR inhibitor and TERT inhibitor combination may construct a novel strategy in cancer stem cells and it can make a double effect on telomerase enzyme. Consequently, inhibition of PI3K/AKT/mTOR signaling pathway components and hTERT activation may prohibit CSC self-renewal and surpass CSC-mediated resistance in order to develop new cancer therapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. GADD34 Keeps the mTOR Pathway Inactivated in Endoplasmic Reticulum Stress Related Autophagy.

    Science.gov (United States)

    Holczer, Marianna; Bánhegyi, Gábor; Kapuy, Orsolya

    2016-01-01

    The balance of protein synthesis and proteolysis (i.e. proteostasis) is maintained by a complex regulatory network in which mTOR (mechanistic target of rapamycin serine/threonine kinase) pathway and unfolded protein response are prominent positive and negative actors. The interplay between the two systems has been revealed; however the mechanistic details of this crosstalk are largely unknown. The aim of the present study was to investigate the elements of crosstalk during endoplasmic reticulum stress and to verify the key role of GADD34 in the connection with the mTOR pathway. Here, we demonstrate that a transient activation of autophagy is present in endoplasmic reticulum stress provoked by thapsigargin or tunicamycin, which is turned into apoptotic cell death. The transient phase can be characterized by the elevation of the autophagic marker LC3II/I, by mTOR inactivation, AMP-activated protein kinase activation and increased GADD34 level. The switch from autophagy to apoptosis is accompanied with the appearance of apoptotic markers, mTOR reactivation, AMP-activated protein kinase inactivation and a decrease in GADD34. Inhibition of autophagy by 3-methyladenine shortens the transient phase, while inhibition of mTOR by rapamycin or resveratrol prolongs it. Inhibition of GADD34 by guanabenz or transfection of the cells with siGADD34 results in down-regulation of autophagy-dependent survival and a quick activation of mTOR, followed by apoptotic cell death. The negative effect of GADD34 inhibition is diminished when guanabenz or siGADD34 treatment is combined with rapamycin or resveratrol addition. These data confirm that GADD34 constitutes a mechanistic link between endoplasmic reticulum stress and mTOR inactivation, therefore promotes cell survival during endoplasmic reticulum stress.

  5. Novel nervous and multi-system regenerative therapeutic strategies for diabetes mellitus with mTOR

    Directory of Open Access Journals (Sweden)

    Kenneth Maiese

    2016-01-01

    Full Text Available Throughout the globe, diabetes mellitus (DM is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder. DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy. The mechanistic target of rapamycin (mTOR is a promising agent for the development of novel regenerative strategies for the treatment of DM. mTOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis, insulin resistance, insulin secretion, stem cell proliferation and differentiation, pancreatic β-cell function, and programmed cell death with apoptosis and autophagy. mTOR is central element for the protein complexes mTOR Complex 1 (mTORC1 and mTOR Complex 2 (mTORC2 and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase (PI 3-K, protein kinase B (Akt, AMP activated protein kinase (AMPK, silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae (SIRT1, Wnt1 inducible signaling pathway protein 1 (WISP1, and growth factors. As a result, mTOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease. Future studies directed to elucidate the delicate balance mTOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.

  6. The interaction between early life epilepsy and autistic-like behavioral consequences: a role for the mammalian target of rapamycin (mTOR pathway.

    Directory of Open Access Journals (Sweden)

    Delia M Talos

    Full Text Available Early life seizures can result in chronic epilepsy, cognitive deficits and behavioral changes such as autism, and conversely epilepsy is common in autistic children. We hypothesized that during early brain development, seizures could alter regulators of synaptic development and underlie the interaction between epilepsy and autism. The mammalian Target of Rapamycin (mTOR modulates protein translation and is dysregulated in Tuberous Sclerosis Complex, a disorder characterized by epilepsy and autism. We used a rodent model of acute hypoxia-induced neonatal seizures that results in long term increases in neuronal excitability, seizure susceptibility, and spontaneous seizures, to determine how seizures alter mTOR Complex 1 (mTORC1 signaling. We hypothesized that seizures occurring at a developmental stage coinciding with a critical period of synaptogenesis will activate mTORC1, contributing to epileptic networks and autistic-like behavior in later life. Here we show that in the rat, baseline mTORC1 activation peaks during the first three postnatal weeks, and induction of seizures at postnatal day 10 results in further transient activation of its downstream targets phospho-4E-BP1 (Thr37/46, phospho-p70S6K (Thr389 and phospho-S6 (Ser235/236, as well as rapid induction of activity-dependent upstream signaling molecules, including BDNF, phospho-Akt (Thr308 and phospho-ERK (Thr202/Tyr204. Furthermore, treatment with the mTORC1 inhibitor rapamycin immediately before and after seizures reversed early increases in glutamatergic neurotransmission and seizure susceptibility and attenuated later life epilepsy and autistic-like behavior. Together, these findings suggest that in the developing brain the mTORC1 signaling pathway is involved in epileptogenesis and altered social behavior, and that it may be a target for development of novel therapies that eliminate the progressive effects of neonatal seizures.

  7. Unique Clones of Vibrio cholerae O1 El Tor with Haitian Type ctxB Allele Implicated in the Recent Cholera Epidemics from Nigeria, Africa.

    Science.gov (United States)

    Adewale, Akinsinde Kehinde; Pazhani, Gururaja Perumal; Abiodun, Iwalokun Bamidele; Afolabi, Oluwadun; Kolawole, Olukoya Daniel; Mukhopadhyay, Asish K; Ramamurthy, Thanadarayan

    2016-01-01

    The antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. In this study, we screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality. All the V. cholerae O1 biotype El Tor isolates isolated during 2007-2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria. Emergence of CT genotype 7 (Haitian type of ctxB allele) was predominantly seen among Ogawa serotype and the CT genotype 1 (classical ctxB allele) was mostly found in Inaba serotype. Overall, V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis. V. cholerae isolates from Abia, Kano and Bauchi were found to be genetically distinct from the other states of Nigeria. Fecal contamination of the water sources may be the possible source of the cholera infection. Combined prevalence of Haitian and classical ctxB alleles were detected in Ogawa and Inaba serotypes, respectively. This study further demonstrated that V. cholerae O1 with the ctxB has been emerged similar to the isolates reported in Haiti. Our findings suggest that the use of fluoroquinolones or tetracycline/doxycycline may help in the effective management of acute cholera in the affected Nigerian states. In addition, strengthening the existing surveillance in the hospitals of all the states and supply of clean drinking water may control cholera outbreaks in the future.

  8. Influence of mTOR in energy and metabolic homeostasis.

    Science.gov (United States)

    Haissaguerre, Magalie; Saucisse, Nicolas; Cota, Daniela

    2014-11-01

    The mechanistic (or mammalian) target of rapamycin couples a variety of different environmental signals, including nutrients and hormones, with the regulation of several energy-demanding cellular functions, spanning from protein and lipid synthesis to mitochondrial activity and cytoskeleton dynamics. mTOR forms two distinct protein complexes in cells, mTORC1 and mTORC2. This review focuses on recent advances made in understanding the roles played by these two complexes in the regulation of whole body metabolic homeostasis. Studies carried out in the past few years have shown that mTORC1 activity in the hypothalamus varies by cell and stimulus type, and that this complex is critically implicated in the regulation of food intake and body weight and in the central actions of both nutrients and hormones, such as leptin, ghrelin and triiodothyronine. As a regulator of cellular anabolic processes, mTORC1 activity in the periphery favors adipogenesis, lipogenesis, glucose uptake and beta-cell mass expansion. Much less is known about the function of mTORC2 in the hypothalamus, while in peripheral organs this second complex exerts roles strikingly similar to those described for mTORC1. Deregulation of mTORC1 and mTORC2 is associated with obesity, type 2 diabetes, cancer and neurodegenerative disorders. Insights on the exact relationship between mTORC1 and mTORC2 in the context of the regulation of metabolic homeostasis and on the specific molecular mechanisms engaged by these two complexes in such regulation may provide new avenues for therapy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. BDNF activates mTOR to regulate GluR1 expression required for memory formation.

    Directory of Open Access Journals (Sweden)

    Leandro Slipczuk

    Full Text Available BACKGROUND: The mammalian target of Rapamycin (mTOR kinase plays a key role in translational control of a subset of mRNAs through regulation of its initiation step. In neurons, mTOR is present at the synaptic region, where it modulates the activity-dependent expression of locally-translated proteins independently of mRNA synthesis. Indeed, mTOR is necessary for different forms of synaptic plasticity and long-term memory (LTM formation. However, little is known about the time course of mTOR activation and the extracellular signals governing this process or the identity of the proteins whose translation is regulated by this kinase, during mnemonic processing. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that consolidation of inhibitory avoidance (IA LTM entails mTOR activation in the dorsal hippocampus at the moment of and 3 h after training and is associated with a rapid and rapamycin-sensitive increase in AMPA receptor GluR1 subunit expression, which was also blocked by intra-hippocampal delivery of GluR1 antisense oligonucleotides (ASO. In addition, we found that pre- or post-training administration of function-blocking anti-BDNF antibodies into dorsal CA1 hampered IA LTM retention, abolished the learning-induced biphasic activation of mTOR and its readout, p70S6K and blocked GluR1 expression, indicating that BDNF is an upstream factor controlling mTOR signaling during fear-memory consolidation. Interestingly, BDNF ASO hindered LTM retention only when given into dorsal CA1 1 h after but not 2 h before training, suggesting that BDNF controls the biphasic requirement of mTOR during LTM consolidation through different mechanisms: an early one involving BDNF already available at the moment of training, and a late one, happening around 3 h post-training that needs de novo synthesis of this neurotrophin. CONCLUSIONS/SIGNIFICANCE: IN CONCLUSION, OUR FINDINGS DEMONSTRATE THAT: 1 mTOR-mediated mRNA translation is required for memory consolidation during

  10. Immunohistochemical Investigation of HER/AKT/mTOR Pathway and Cellular Adhesion Molecules in Urothelial Carcinomas

    Directory of Open Access Journals (Sweden)

    Nikolaos Koletsas

    2017-01-01

    Full Text Available Background. Several investigators have suggested the possibility that the expression of both EGFR and HER2 could be utilized for molecularly targeted therapy in urinary bladder cancer. We tried to evaluate the expression of HER2 and EGFR and activation of the AKT/PTEN/mTOR pathway in urothelial carcinomas and if there is any association between them and cellular adhesion molecules (CAMs. Materials and Methods. Forty-one paraffin-embedded urothelial cancer tissue blocks were collected. Immunostains for HER2, EGFR, MIB1, phospho-AKT, PTEN, phospho-mTOR, e-cadherin, p-cadherin, and b-catenin were performed on tissue microarrays sections. The immunohistochemical results were correlated with clinicopathological parameters. Results. The overexpression of HER2 was found in 19.6% of the cases and it was associated with high grade tumors with a high mitotic index and phosphorylation of AKT and mTOR. Muscle-invasive tumors presented both cytoplasmic and nuclear losses of PTEN expression. There was no association between HER/AKT/mTOR pathway activation and CAM expression. Although cadherins were often coexpressed, only p-cadherin immunoreactivity was associated with tumor grade and high proliferative index. Conclusions. HER2 overexpression is found in a respective proportion of urothelial carcinomas. P-cadherin expression is associated with high grade UCs but it is not affected by HER2 overexpression or by activation of HER/AKT/mTOR pathway.

  11. Curcumin targets the AKT-mTOR pathway for uterine leiomyosarcoma tumor growth suppression.

    Science.gov (United States)

    Wong, Tze Fang; Takeda, Takashi; Li, Bin; Tsuiji, Kenji; Kondo, Akiko; Tadakawa, Mari; Nagase, Satoru; Yaegashi, Nobuo

    2014-04-01

    Uterine leiomyosarcomas generally do not respond well to standard chemotherapy. We previously demonstrated that curcumin, the active ingredient derived from the herb Curcuma longa, inhibits uterine leiomyosarcoma cells in vitro via the inhibition of the AKT-mammalian target of rapamycin (mTOR) pathway. As a preclinical investigation, we performed an in vivo study using female nude mice to confirm the therapeutic potential of curcumin against uterine leiomyosarcoma. Human leiomyosarcoma cells, SK-UT-1, were inoculated in female nude mice to establish subcutaneous tumors. Either vehicle control or 250 mg/kg curcumin was administered intraperitoneally every day for 14 consecutive days, and the mice were then killed. The tumors were measured every 2-3 days. The tumors were processed for immunohistochemical analyses to detect total AKT, phosphorylated AKT, total mTOR, phosphorylated mTOR, and phosphorylated S6. To detect apoptosis, the tumors were stained for cleaved PARP and TUNEL. Ki-67 immunohistochemistry was performed to determine cell viability of the tumors. Compared with the control, curcumin reduced uterine leiomyosarcoma tumor volume and mass significantly with a concordant decrease in mTOR and S6 phosphorylation. However, AKT phosphorylation was not significantly altered. Cleaved PARP and TUNEL staining increased significantly with curcumin administration, indicating the induction of apoptosis. There was no difference in Ki-67 staining between the two groups. Curcumin inhibited uterine leiomyosarcoma tumor growth in vivo by targeting the AKT-mTOR pathway for inhibition.

  12. mTOR Promotes Survival and Astrocytic Characteristics Induced by Pten/Akt Signaling in Glioblastoma

    Directory of Open Access Journals (Sweden)

    Xiaoyi Hu

    2005-04-01

    Full Text Available Combined activation of Ras and Akt leads to the formation of astrocytic glioblastoma multiforme (GBM in mice. In human GBMs, AKT is not mutated but is activated in approximately 70% of these tumors, in association with loss of PTEN and/or activation of receptor tyrosine kinases. Mechanistic justification for the therapeutic blockade of targets downstream of AKT, such as mTOR, in these cancers requires demonstration that the oncogenic effect of PTEN loss is through elevated AKT activity. We demonstrate here that loss of Pten is similar to Akt activation in the context of glioma formation in mice. We further delineate the role of mTOR activity downstream of Akt in the maintenance of Akt+KRas-induced GBMs. Blockade of mTOR results in regional apoptosis in these tumors and conversion in the character of surviving tumor cells from astrocytoma to oligodendroglioma. These data suggest that mTOR activity is required for the survival of some cells within these GBMs, and mTOR appears required for the maintenance of astrocytic character in the surviving cells. Furthermore, our study provides the first example of conversion between two distinct tumor types usually thought of as belonging to specific lineages, and provides evidence for signal transduction-mediated transdifferentiation between glioma subtypes.

  13. Involvement of mTOR signaling in sphingosylphosphorylcholine-induced hypopigmentation effects

    Directory of Open Access Journals (Sweden)

    Jeong Hyo-Soon

    2011-08-01

    Full Text Available Abstract Background Sphingosylphosphorylcholine (SPC acts as a potent lipid mediator and signaling molecule in various cell types. In the present study, we investigated the effects of SPC on melanogenesis and SPC-modulated signaling pathways related to melanin synthesis. Methods Melanin production was measured in Mel-Ab cells. A luciferase assay was used to detect transcriptional activity of the MITF promoter. Western blot analysis was performed to examine SPC-induced signaling pathways. Results SPC produced significant hypopigmentation effects in a dose-dependent manner. It was found that SPC induced not only activation of Akt but also stimulation of mTOR, a downstream mediator of the Akt signaling pathway. Moreover, SPC decreased the levels of LC3 II, which is known to be regulated by mTOR. Treatment with the mTOR inhibitor rapamycin eliminated decreases in melanin and LC3 II levels by SPC. Furthermore, we found that the Akt inhibitor LY294002 restored SPC-mediated downregulation of LC3 II and inhibited the activation of mTOR by SPC. Conclusions Our data suggest that the mTOR signaling pathway is involved in SPC-modulated melanin synthesis.

  14. Ghrelin promotes hepatic lipogenesis by activation of mTOR-PPARγ signaling pathway

    Science.gov (United States)

    Li, Ziru; Xu, Geyang; Qin, Yan; Zhang, Chao; Tang, Hong; Yin, Yue; Xiang, Xinxin; Li, Yin; Zhao, Jing; Mulholland, Michael; Zhang, Weizhen

    2014-01-01

    Although ghrelin has been demonstrated to stimulate energy intake and storage through a central mechanism, its effect on hepatic lipid metabolism remains largely uncharacterized. Ghrelin receptor antagonism or gene deletion significantly decreased obesity-associated hepatic steatosis by suppression of de novo lipogenesis, whereas exogenous ghrelin stimulated lipogenesis, leading to hepatic lipid accumulation in mice. The effects of ghrelin were mediated by direct activation of its receptor on hepatocytes. Cultured hepatocytes responded to ghrelin with increased lipid content and expression of lipogenesis-related genes. Ghrelin increased phosphorylation of S6, the downstream target of mammalian target of rapamycin (mTOR) signaling in cultured hepatocytes, whereas ghrelin receptor antagonism reduced hepatic phosphorylation of S6 in db/db mice. Inhibition of mTOR signaling by rapamycin markedly attenuated ghrelin-induced up-regulation of lipogenesis in hepatocytes, whereas activation of hepatic mTOR signaling by deletion of TSC1 increased hepatic lipogenesis. By interacting with peroxisome proliferator-activated receptor-γ (PPARγ), mTOR mediates the ghrelin-induced up-regulation of lipogenesis in hepatocytes. The stimulatory effect of ghrelin on hepatic lipogenesis was significantly attenuated by PPARγ antagonism in cultured hepatocytes and in PPARγ gene-deficient mice. Our study indicates that ghrelin activates its receptor on hepatocytes to promote lipogenesis via a mechanism involving the mTOR-PPARγ signaling pathway. PMID:25157160

  15. Distinct amino acid-sensing mTOR pathways regulate skeletal myogenesis.

    Science.gov (United States)

    Yoon, Mee-Sup; Chen, Jie

    2013-12-01

    Signaling through the mammalian target of rapamycin (mTOR) in response to amino acid availability controls many cellular and developmental processes. mTOR is a master regulator of myogenic differentiation, but the pathways mediating amino acid signals in this process are not known. Here we examine the Rag GTPases and the class III phosphoinositide 3-kinase (PI3K) Vps34, two mediators of amino acid signals upstream of mTOR complex 1 (mTORC1) in cell growth regulation, for their potential involvement in myogenesis. We find that, although both Rag and Vps34 mediate amino acid activation of mTORC1 in C2C12 myoblasts, they have opposing functions in myogenic differentiation. Knockdown of RagA/B enhances, whereas overexpression of active RagB/C mutants impairs, differentiation, and this inhibitory function of Rag is mediated by mTORC1 suppression of the IRS1-PI3K-Akt pathway. On the other hand, Vps34 is required for myogenic differentiation. Amino acids activate a Vps34-phospholipase D1 (PLD1) pathway that controls the production of insulin-like growth factor II, an autocrine inducer of differentiation, through the Igf2 muscle enhancer. The product of PLD, phosphatidic acid, activates the enhancer in a rapamycin-sensitive but mTOR kinase-independent manner. Our results uncover amino acid-sensing mechanisms controlling the homeostasis of myogenesis and underline the versatility and context dependence of mTOR signaling.

  16. mTOR Overactivation and Compromised Autophagy in the Pathogenesis of Pulmonary Fibrosis.

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    Yao-Song Gui

    Full Text Available The mammalian target of rapamycin (mTOR signaling pathway in pulmonary fibrosis was investigated in cell and animal models. mTOR overactivation in alveolar epithelial cells (AECs was achieved in the conditional and inducible Tsc1 knock-down mice SPC-rtTA/TetO-Cre/Tsc1(fx/+ (STT. Doxycycline caused Tsc1 knock-down and consequently mTOR activation in AECs for the STT mice. Mice treated with bleomycin exhibited increased mortality and pulmonary fibrosis compared with control mice. In wild-type C57BL/6J mice, pretreatment with rapamycin attenuated the bleomycin-mediated mortality and fibrosis. Rapamycin-mediated mouse survival benefit was inhibited by chloroquine, an autophagy inhibitor. Autophagosomes were decreased in the lungs after bleomycin exposure. Rapamycin induced the production of autophagosomes and diminished p62. We concluded that mTOR overactivation in AECs and compromised autophagy in the lungs are involved in the pathogenesis of pulmonary fibrosis. The suppression of mTOR and enhancement of autophagy may be used for treatment of pulmonary fibrosis.

  17. A possible link between BDNF and mTOR in control of food intake

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    Nobuyuki eTakei

    2014-09-01

    Full Text Available Food intake is intricately regulated by glucose, amino acids, hormones, neuropeptides, and trophic factors through a neural circuit in the hypothalamus. Brain-derived neurotrophic factor (BDNF, the most prominent neurotrophic factor in the brain, regulates differentiation, maturation, and synaptic plasticity throughout life. Among its many roles, BDNF exerts an anorexigenic function in the brain. However, the intracellular signaling induced by BDNF to control food intake is not fully understood. One candidate for the molecule involved in transducing the anorexigenic activity of BDNF is the mammalian target of rapamycin (mTOR. mTOR senses extracellular amino acids, glucose, growth factors, and neurotransmitters, and regulates anabolic reactions response to these signals. Activated mTOR increases protein and lipid synthesis and inhibits protein degradation. In the hypothalamus, mTOR activation is thought to reduce food intake. Here we summarize recent findings regarding BDNF- and mTOR-mediated feeding control, and propose a link between these molecules in eating behavior.

  18. Central exercise action increases the AMPK and mTOR response to leptin.

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    Eduardo R Ropelle

    Full Text Available AMP-activated protein kinase (AMPK and mammalian Target of Rapamycin (mTOR are key regulators of cellular energy balance and of the effects of leptin on food intake. Acute exercise is associated with increased sensitivity to the effects of leptin on food intake in an IL-6-dependent manner. To determine whether exercise ameliorates the AMPK and mTOR response to leptin in the hypothalamus in an IL-6-dependent manner, rats performed two 3-h exercise bouts, separated by one 45-min rest period. Intracerebroventricular IL-6 infusion reduced food intake and pretreatment with AMPK activators and mTOR inhibitor prevented IL-6-induced anorexia. Activators of AMPK and fasting increased food intake in control rats to a greater extent than that observed in exercised ones, whereas inhibitor of AMPK had the opposite effect. Furthermore, the reduction of AMPK and ACC phosphorylation and increase in phosphorylation of proteins involved in mTOR signal transduction, observed in the hypothalamus after leptin infusion, were more pronounced in both lean and diet-induced obesity rats after acute exercise. Treatment with leptin reduced food intake in exercised rats that were pretreated with vehicle, although no increase in responsiveness to leptin-induced anorexia after pretreatment with anti-IL6 antibody, AICAR or Rapamycin was detected. Thus, the effects of leptin on the AMPK/mTOR pathway, potentiated by acute exercise, may contribute to appetite suppressive actions in the hypothalamus.

  19. Tongue base exposure during TORS without the use of a mouth prop.

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    Miller, Matthew C

    2016-12-01

    This study describes a novel exposure technique for base of tongue trans-oral robotic surgery (BOT TORS) and early experience with it. The technique discussed involves placement of a suture through the mobile tongue with distraction and suspension of the tongue to the operating table. TORS is then performed per previously described techniques. In our series, 13 patients with either benign or malignant mass lesions involving the tongue base were treated with TORS at a tertiary academic medical center. We reviewed the rates of adequate exposure, console time, adequacy of resection (in malignant cases), complication rates, and costs associated with this technique. In our series, adequate exposure was achieved in 92.3 % of patients. Mean console time was 36 min. Negative surgical margins were achieved in all cancer resections. Five minor complications (tongue lacerations) were observed. Per-case cost attributable to this technique is $3.81. We conclude that BOT TORS is feasible without the use of a mouth prop. Operative times are consistent with those reported by centers that routinely use mouth props for BOT TORS. This technique does not appear to compromise margin adequacy during oncologic resections. Its use may result in a significant cost savings when compared to the FK and other similar retractors.

  20. Epidemiologic and Drug Resistance Pattern of Vibrio cholerae O1 Biotype El Tor, Serotype Ogawa, in the 2011 Cholera Outbreak, in Alborz Province, Iran.

    Science.gov (United States)

    Barati, Hojatolah; Moradi, Ghobad; Rasouli, Mohammad Aziz; Mohammadi, Parvin

    2015-11-01

    Although the national guidelines recommend special antibiotics, based on the antibiogram of National Reference Laboratory, it seems that, because of uncontrolled usage of antibiotics in the society and due to the changes in the serotypes causing the disease, it is essential to monitor the status of drug resistance, permanently, and to revise the current prescriptions guidelines. This study aimed to assess the epidemiological aspects and drug resistance pattern of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, in cholera outbreak, in Alborz province in Iran, during 2011. This is a cross-sectional study, which reviews a cholera epidemic that occurred in Iran. A total of 9844 specimens were taken from suspected cases, among diarrheal patients, via rectal swabs. The specimens were placed in Cary-Blair transport medium and sent to laboratory. Samples were enriched, in alkaline peptone water, and isolated on thiosulphate-citrate-bile salt-sucrose agar. From the 244 confirmed cases, 239 cases underwent antibiogram test, via disk diffusion method and based on national committee for clinical laboratory standards (NCCLS) instructions. The standard Escherichia coli ATCC 25922 was used for antibiogram quality control and, eventually, all results were interpreted and reported using NCCLS standard table. In total, until October 22, 2011, which was announced as the end of outbreak, 9844 samples were taken from diarrheal patients. Regarding the type of V. cholerae, 244 El Tor biotype positive cases were reported. The case fatality rate was 1.3%. The mean age of patients was 37.8 years and the highest incidence rate occurred in the age group 21 - 30 years. After conducting antibiotic susceptibility test in the 244 V. cholerae, biotype El Tor, serotype Ogawa, it was found that ciprofloxacin had the highest level of antibiotic susceptibility (99.6%) and the highest level of antibiotic resistance was observed in co-trimoxazole (95.4%). The results of our study show that the

  1. Genetic Susceptibility to Atherosclerosis

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    Sanja Kovacic

    2012-01-01

    Full Text Available Atherosclerosis is a complex multifocal arterial disease involving interactions of multiple genetic and environmental factors. Advances in techniques of molecular genetics have revealed that genetic ground significantly influences susceptibility to atherosclerotic vascular diseases. Besides further investigations of monogenetic diseases, candidate genes, genetic polymorphisms, and susceptibility loci associated with atherosclerotic diseases have been identified in recent years, and their number is rapidly increasing. This paper discusses main genetic investigations fields associated with human atherosclerotic vascular diseases. The paper concludes with a discussion of the directions and implications of future genetic research in arteriosclerosis with an emphasis on prospective prediction from an early age of individuals who are predisposed to develop premature atherosclerosis as well as to facilitate the discovery of novel drug targets.

  2. Cardiac mTOR rescues the detrimental effects of diet-induced obesity in the heart after ischemia-reperfusion.

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    Aoyagi, Toshinori; Higa, Jason K; Aoyagi, Hiroko; Yorichika, Naaiko; Shimada, Briana K; Matsui, Takashi

    2015-06-15

    Diet-induced obesity deteriorates the recovery of cardiac function after ischemia-reperfusion (I/R) injury. While mechanistic target of rapamycin (mTOR) is a key mediator of energy metabolism, the effects of cardiac mTOR in ischemic injury under metabolic syndrome remains undefined. Using cardiac-specific transgenic mice overexpressing mTOR (mTOR-Tg mice), we studied the effect of mTOR on cardiac function in both ex vivo and in vivo models of I/R injury in high-fat diet (HFD)-induced obese mice. mTOR-Tg and wild-type (WT) mice were fed a HFD (60% fat by calories) for 12 wk. Glucose intolerance and insulin resistance induced by the HFD were comparable between WT HFD-fed and mTOR-Tg HFD-fed mice. Functional recovery after I/R in the ex vivo Langendorff perfusion model was significantly lower in HFD-fed mice than normal chow diet-fed mice. mTOR-Tg mice demonstrated better cardiac function recovery and had less of the necrotic markers creatine kinase and lactate dehydrogenase in both feeding conditions. Additionally, mTOR overexpression suppressed expression of proinflammatory cytokines, including IL-6 and TNF-α, in both feeding conditions after I/R injury. In vivo I/R models showed that at 1 wk after I/R, HFD-fed mice exhibited worse cardiac function and larger myocardial scarring along myofibers compared with normal chow diet-fed mice. In both feeding conditions, mTOR overexpression preserved cardiac function and prevented myocardial scarring. These findings suggest that cardiac mTOR overexpression is sufficient to prevent the detrimental effects of diet-induced obesity on the heart after I/R, by reducing cardiac dysfunction and myocardial scarring. Copyright © 2015 the American Physiological Society.

  3. Predicting mTOR inhibitors with a classifier using recursive partitioning and Naïve Bayesian approaches.

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    Ling Wang

    Full Text Available BACKGROUND: Mammalian target of rapamycin (mTOR is a central controller of cell growth, proliferation, metabolism, and angiogenesis. Thus, there is a great deal of interest in developing clinical drugs based on mTOR. In this paper, in silico models based on multi-scaffolds were developed to predict mTOR inhibitors or non-inhibitors. METHODS: First 1,264 diverse compounds were collected and categorized as mTOR inhibitors and non-inhibitors. Two methods, recursive partitioning (RP and naïve Bayesian (NB, were used to build combinatorial classification models of mTOR inhibitors versus non-inhibitors using physicochemical descriptors, fingerprints, and atom center fragments (ACFs. RESULTS: A total of 253 models were constructed and the overall predictive accuracies of the best models were more than 90% for both the training set of 964 and the external test set of 300 diverse compounds. The scaffold hopping abilities of the best models were successfully evaluated through predicting 37 new recently published mTOR inhibitors. Compared with the best RP and Bayesian models, the classifier based on ACFs and Bayesian shows comparable or slightly better in performance and scaffold hopping abilities. A web server was developed based on the ACFs and Bayesian method (http://rcdd.sysu.edu.cn/mtor/. This web server can be used to predict whether a compound is an mTOR inhibitor or non-inhibitor online. CONCLUSION: In silico models were constructed to predict mTOR inhibitors using recursive partitioning and naïve Bayesian methods, and a web server (mTOR Predictor was also developed based on the best model results. Compound prediction or virtual screening can be carried out through our web server. Moreover, the favorable and unfavorable fragments for mTOR inhibitors obtained from Bayesian classifiers will be helpful for lead optimization or the design of new mTOR inhibitors.

  4. Marijuana Usage and Hypnotic Susceptibility

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    Franzini, Louis R.; McDonald, Roy D.

    1973-01-01

    Anonymous self-reported drug usage data and hypnotic susceptibility scores were obtained from 282 college students. Frequent marijuana users (more than 10 times) showed greater susceptibility to hypnosis than nonusers. (Author)

  5. Representações sociais e território nas letras de funk proibido de facção

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    Andréa Rodriguez

    2011-12-01

    Full Text Available Este artigo apresenta, por meio de uma análise de letras de funk “proibido de facção”, uma leitura da territorialidade do tráfico de drogas nas favelas. Esse estilo musical, que expressa uma cultura específica da juventude urbana pobre, revela cenas de um cotidiano pouco conhecido pela maior parte da população. Para tal, foi realizada a análise do conteúdo de 50 letras de funk, de forma a se compreenderem questões que esse tipo de narrativa faz circular. Destaca-se o território e a territorialidade como categorias de análise que revelam a dinâmica que o tráfico de drogas impõe nos espaços populares da cidade e que incidem diretamente nas representações sociais e práticas dos moradores das favelas.

  6. Pyrazolyl conjugates of bombesin: a new tridentate ligand framework for the stabilization of fac-[M(CO){sub 3}]{sup +} moiety

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Susana; Correia, Joao D.G.; Santos, Isabel [Departamento de Quimica, Instituto Tecnologico e Nuclear, 2686-953 Sacavem (Portugal); Veerendra, Bhadrasetty [Department of Radiology, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Sieckman, Gary L. [Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States); Hoffman, Timothy J. [Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States)]|[Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States)]|[Radiopharmaceutical Sciences Institute, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Rold, Tammy L. [Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Figueroa, Said Daibes [Radiopharmaceutical Sciences Institute, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Retzloff, Lauren [Department of Radiology, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); McCrate, Joseph [Department of Radiology, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Prasanphanich, Adam [Department of Radiology, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States); Smith, Charles J. [Department of Radiology, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States)]|[University of Missouri Research Reactor Center, University of Missouri-Columbia, Columbia, MO 65211 (United States)]|[Research Division, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201 (United States)]|[Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, MO 65211 (United States)]. E-mail: smithcj@health.missouri.edu

    2006-07-15

    We have described the synthesis of tridentate pyrazolyl ligand frameworks for coordination to the fac-[*M(CO){sub 3}]{sup +} metal fragment (*M={sup 186/188}Re or {sup 99m}Tc). These ligands impart a degree of kinetic inertness on the metal center, warranting their study in biological systems. We herein report in vitro/in vivo radiolabeling investigations of a new series of pyrazolyl bombesin (BBN) conjugates radiolabeled via the Isolink kit. These new conjugates are based on the general structure [{sup 99m}Tc-pyrazolyl-X-BBN[7-14]NH{sub 2}], where X={beta}-alanine, serylserylserine or glycylglycylglycine. The pyrazolyl ligand is a tridentate ligand framework that coordinates the metal center through nitrogen donor atoms. The results of these investigations demonstrate the ability of these new conjugates to specifically target the gastrin-releasing peptide receptor subtype 2, which is overexpressed on human prostate PC-3 cancerous tissues. Therefore, these studies suggest the tridentate pyrazolyl ligand framework to be an ideal candidate for the design and development of low-valent {sup 99m}Tc-based diagnostic radiopharmaceuticals based on BBN or other targeting vectors.

  7. Influence of bidentate ligand donor types on the formation and stability in 2 + 1 fac-[M(I)(CO)3](+) (M = Re, (99m)Tc) complexes.

    Science.gov (United States)

    Hayes, Thomas R; Bottorff, Shalina C; Slocumb, Winston S; Barnes, Charles L; Clark, Aurora E; Benny, Paul D

    2017-01-24

    In the last two decades, a number of chelate strategies have been proposed for the fac-[M(I)(CO)3](+) (M = Re, (99m)Tc) core in radiopharmaceutical applications. However, the development of new ligands/complexes with improved function and in vivo performance has been limited in recent years. Expanding on our previous studies using the 2 + 1 labeling strategy, a series of bidentate ligands (neutral vs. anionic) containing an aromatic amine in combination with monodentate pyridine analogs or imidazole were explored to determine the influence of the bidentate and monodentate ligands on the formation and stability of the respective complexes. The 2 + 1 complexes with Re and (99m)Tc were synthesized in two steps and characterized by standard radio/chemical methods. X-ray characterization and density functional theory analysis of the Re 2 + 1 complexes with the complete bidentate series with 4-dimethylaminopyridine were conducted, indicating enhanced ligand binding energies of the neutral over anionic ligands. In the (99m)Tc studies, anionic bidentate ligands had significantly higher formation yields of the 2 + 1 product, but neutral ligands appear to have increased stability in an amino acid challenge assay. Both bidentate series exhibited improved stability by increasing the basicity of the pyridine ligands.

  8. The role of mTOR in lipid homeostasis and diabetes progression.

    Science.gov (United States)

    Chakrabarti, Partha; Kandror, Konstantin V

    2015-10-01

    Metabolic diseases, such as type 2 diabetes, cardiac dysfunction, hypertension, and hepatic steatosis, share one critical causative factor: abnormal lipid partitioning, that redistribution of triglycerides from adipocytes to nonadipose peripheral tissues. Lipid overload of these tissues causes a number of pathological effects collectively known as lipotoxicity. If we find the way to correct lipid partitioning, we will restrain metabolic diseases, improve life quality and life expectancy and radically reduce healthcare costs. Lipid partitioning in the body is maintained by tightly regulated and balanced rates of de novo lipogenesis, lipolysis, adipogenesis, and mitochondrial oxidation primarily in fat and liver. Recent studies highlighted in this review have established mTOR as a central regulator of lipid storage and metabolism. Increased activity of mTOR in obesity may compensate for the negative consequences of overnutrition, whereas dysregulation of mTOR may lead to abnormal lipid partitioning and metabolic disease.

  9. The role of the Akt/mTOR pathway in tobacco-carcinogen induced lung tumorigenesis

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    Memmott, Regan M.; Dennis, Phillip A.

    2009-01-01

    Lung cancer is the leading cause of cancer-related death in the United States, and 85–90% of lung cancer cases are associated with tobacco use. Tobacco components promote lung tumorigenesis through genotoxic effects, as well as through biochemical modulation of signaling pathways such as the Akt/mTOR pathway that regulate cell proliferation and survival. This review will describe cell surface receptors and other upstream components required for tobacco-carcinogen induced activation of Akt and mTOR. Preclinical studies demonstrate that inhibitors of the Akt/mTOR pathway inhibit tumor formation in mouse models of carcinogen-induced lung tumorigenesis. Some of these inhibitors will be highlighted, and their clinical potential for the treatment and prevention of lung cancer will be discussed. PMID:20028747

  10. The TOR Signaling Pathway in Spatial and Temporal Control of Cell Size and Growth

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    Suam Gonzalez

    2017-06-01

    Full Text Available Cell size is amenable by genetic and environmental factors. The highly conserved nutrient-responsive Target of Rapamycin (TOR signaling pathway regulates cellular metabolic status and growth in response to numerous inputs. Timing and duration of TOR pathway activity is pivotal for both cell mass built up as well as cell cycle progression and is controlled and fine-tuned by the abundance and quality of nutrients, hormonal signals, growth factors, stress, and oxygen. TOR kinases function within two functionally and structurally discrete multiprotein complexes, TORC1 and TORC2, that are implicated in temporal and spatial control of cell size and growth respectively; however, recent data indicate that such functional distinctions are much more complex. Here, we briefly review roles of the two complexes in cellular growth and cytoarchitecture in various experimental model systems.

  11. mTOR Signaling in Protein Translation Regulation: Implications in Cancer Genesis and Therapeutic Interventions

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    Mehvish Showkat

    2014-01-01

    Full Text Available mTOR is a central nutrient sensor that signals a cell to grow and proliferate. Through distinct protein complexes it regulates different levels of available cellular energy substrates required for cell growth. One of the important functions of the complex is to maintain available amino acid pool by regulating protein translation. Dysregulation of mTOR pathway leads to aberrant protein translation which manifests into various pathological states. Our review focuses on the role mTOR signaling plays in protein translation and its physiological role. It also throws some light on available data that show translation dysregulation as a cause of pathological complexities like cancer and the available drugs that target the pathway for cancer treatment.

  12. Aberrant mTOR activation in senescence and aging: A mitochondrial stress response?

    Science.gov (United States)

    Nacarelli, Timothy; Azar, Ashley; Sell, Christian

    2015-08-01

    Unexpected activation of mTOR signaling, measured by ribosomal S6 phosphorylation or ribosomal S6 kinase (p70S6K) activity, has been reported in aging-related settings. Evidence of elevated mTOR activity has been reported in the heart and muscle tissue in aged mice and humans, mouse models of progeria, and senescent human fibroblasts. We explore these reports and the possibility that activation of the mTOR/p70S6K kinase pathway may represent a ROS-mediated response to mitochondrial stress leading to the activation of senescence. This activation is a hallmark of both aged tissue and senescent human cells. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Synergistic antiproliferative and antiangiogenic effects of EGFR and mTOR inhibitors.

    Science.gov (United States)

    Porcelli, L; Quatrale, A E; Mantuano, P; Silvestris, N; Rolland, J F; Biancolillo, L; Paradiso, A; Azzariti, A

    2013-01-01

    Single-agent therapy with molecularly targeted agents has shown limited success in tumor growth control, mainly because escape or resistance mechanisms are activated once a signalling molecule is inhibited. Rational combinations of target-specific agents could counteract this response providing a useful strategy in cancer treatment. In this regard, the EGFR and mTOR inhibitors have been used together to generate a synergistic effect and maximize the efficacy of each individual agent. Overall, the in vivo and in vitro evidences support the utilization of combinations targeting EGFR and mTOR, for malignancies characterized by deregulated EGFR/PI3K/Akt/ mTOR signalling cascade; whereas the clinical experience points out that the assessment of the therapeutic value of such combination awaits further investigations.

  14. Neuropathological role of PI3K/Akt/mTOR axis in Down syndrome brain.

    Science.gov (United States)

    Perluigi, Marzia; Pupo, Gilda; Tramutola, Antonella; Cini, Chiara; Coccia, Raffaella; Barone, Eugenio; Head, Elizabeth; Butterfield, D Allan; Di Domenico, Fabio

    2014-07-01

    Down syndrome (DS) is the most frequent genetic cause of intellectual disability characterized by the presence of three copies of chromosome 21 (Chr21). Individuals with DS have sufficient neuropathology for a diagnosis of Alzheimer's disease (AD) after the age of 40years. The aim of our study is to gain new insights in the molecular mechanisms impaired in DS subjects that eventually lead to the development of dementia. We evaluate the PI3K/Akt/mTOR axis in the frontal cortex from DS cases (under the age of 40years) and DS with AD neuropathology compared with age-matched controls (Young and Old). The PI3K/Akt/mTOR axis may control several key pathways involved in AD that, if aberrantly regulated, affect amyloid beta (Aβ) deposition and tau phosphorylation. Our results show a hyperactivation of PI3K/Akt/mTOR axis in individuals with DS, with and without AD pathology, in comparison with respective controls. The PI3K/Akt/mTOR deregulation results in decreased autophagy, inhibition of IRS1 and GSK3β activity. Moreover, our data suggest that aberrant activation of the PI3K/Akt/mTOR axis acts in parallel to RCAN1 in phosphorylating tau, in DS and DS/AD. In conclusion, this study provides insights into the neuropathological mechanisms that may be engaged during the development of AD in DS. We suggest that deregulation of this signaling cascade is already evident in young DS cases and persist in the presence of AD pathology. The impairment of the PI3K/Akt/mTOR axis in DS population might represent a key-contributing factor to the neurodegenerative process that culminates in Alzheimer-like dementia. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Coffee consumption in aged mice increases energy production and decreases hepatic mTOR levels.

    Science.gov (United States)

    Takahashi, Keita; Yanai, Shuichi; Shimokado, Kentaro; Ishigami, Akihito

    2017-06-01

    Coffee, one of the world's most consumed beverages, has many benefits. Some studies have reported the effects of coffee on aging. The aim of this study was to investigate the locomotor activity, energy metabolism, and lipid metabolism of aged (20-mo-old) mice given coffee. Aged C57 BL/6 NCr mice were divided into three groups: controls that were not given coffee (n = 9), a group that received 0.1% caffeinated coffee (n = 9), and a group that received 0.1% decaffeinated coffee (n = 9). This regimen continued for 17 wk until mice reached the age of 24 mo. Regular and decaffeinated coffee consumption decreased plasma-free fatty acid levels, increased hepatic adenosine triphosphate content, and decreased total mammalian target of rapamycin (mTOR) and phosphorylated mTOR (p-mTOR) protein content in the liver. However, no differences were found in the protein or activity levels of Akt, adenosine monophosphate-activated protein kinase (AMPK), p70 S6 kinase, or sterol regulatory element-binding protein 1, proteins that are upstream or downstream of the mTOR complex 1 (mTORC1)-related pathways. Regular coffee consumption increased food and water intake, locomotor activity, the volume of carbon dioxide production, and the respiration exchange ratio. Regular and decaffeinated coffee consumption decreased hepatic total mTOR and p-mTOR levels independently of Akt and AMPK pathways in aged mice. Because decreased mTORC1 activity is known to have antiaging effects, coffee consumption during old age may retard aging. Moreover, coffee consumption by the aged population had a positive effect on behavioral energy and lipid metabolism. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Glucose Regulation of Load‐Induced mTOR Signaling and ER Stress in Mammalian Heart

    Science.gov (United States)

    Sen, Shiraj; Kundu, Bijoy K.; Wu, Henry Cheng‐Ju; Hashmi, S. Shahrukh; Guthrie, Patrick; Locke, Landon W.; Roy, R. Jack; Matherne, G. Paul; Berr, Stuart S.; Terwelp, Matthew; Scott, Brian; Carranza, Sylvia; Frazier, O. Howard; Glover, David K.; Dillmann, Wolfgang H.; Gambello, Michael J.; Entman, Mark L.; Taegtmeyer, Heinrich

    2013-01-01

    Background Changes in energy substrate metabolism are first responders to hemodynamic stress in the heart. We have previously shown that hexose‐6‐phosphate levels regulate mammalian target of rapamycin (mTOR) activation in response to insulin. We now tested the hypothesis that inotropic stimulation and increased afterload also regulate mTOR activation via glucose 6‐phosphate (G6P) accumulation. Methods and Results We subjected the working rat heart ex vivo to a high workload in the presence of different energy‐providing substrates including glucose, glucose analogues, and noncarbohydrate substrates. We observed an association between G6P accumulation, mTOR activation, endoplasmic reticulum (ER) stress, and impaired contractile function, all of which were prevented by pretreating animals with rapamycin (mTOR inhibition) or metformin (AMPK activation). The histone deacetylase inhibitor 4‐phenylbutyrate, which relieves ER stress, also improved contractile function. In contrast, adding the glucose analogue 2‐deoxy‐d‐glucose, which is phosphorylated but not further metabolized, to the perfusate resulted in mTOR activation and contractile dysfunction. Next we tested our hypothesis in vivo by transverse aortic constriction in mice. Using a micro‐PET system, we observed enhanced glucose tracer analog uptake and contractile dysfunction preceding dilatation of the left ventricle. In contrast, in hearts overexpressing SERCA2a, ER stress was reduced and contractile function was preserved with hypertrophy. Finally, we examined failing human hearts and found that mechanical unloading decreased G6P levels and ER stress markers. Conclusions We propose that glucose metabolic changes precede and regulate functional (and possibly also structural) remodeling of the heart. We implicate a critical role for G6P in load‐induced mTOR activation and ER stress. PMID:23686371

  17. Additive cytotoxic effects of radiation and mTOR inhibitors in a cervical cancer cell line.

    Science.gov (United States)

    Assad, Daniele Xavier; Borges, Gabriel Alvares; Avelino, Samuel Ramalho; Guerra, Eliete Neves Silva

    2018-02-01

    The PI3K/AKT/mTOR signaling pathway is frequently activated in HPV-positive cervical squamous cell cancer (CC). This study investigated the biological effects of mTOR inhibitors associated with radiotherapy in a CC cell line (HeLa). A human keratinocyte cell line (HaCaT) was used as control. Temsirolimus, everolimus, resveratrol, curcumin and epigallocatechin gallate (EGCG) were the mTOR inhibitors assessed. The 50% cell cytotoxicity rate (CC 50 ) for each treatment was determined by MTT cell viability assay. Cells were pre-treated with mTOR inhibitors at CC 50 followed by radiotherapy (RT) at 2Gy. Cell death profile after treatment with temsirolimus, resveratrol and curcumin was assessed with flow cytometry. Everolimus, temsirolimus, EGCG, resveratrol and curcumin were cytotoxic to HeLa. Radiation induced a statistically significant (p<0.01) supra-additive cytotoxic effect in the cervical cancer cell line when combined with mTOR inhibitors. After a 24-h treatment, EGCG and resveratrol were more cytotoxic to HeLa cells than to HaCaT cells. After 48h of treatment, resveratrol, curcumin and everolimus were more cytotoxic to HeLa cells when compared to HaCaT cells. After 24h, temsirolimus induced late apoptosis or necrosis in HeLa cells. Based on these data, new studies with mTOR inhibitors as treatment options for cervical cancer are recommended, mainly combined to radiotherapy. Copyright © 2017 Elsevier GmbH. All rights reserved.

  18. High-throughput mutational analysis of TOR1A in primary dystonia.

    Science.gov (United States)

    Xiao, Jianfeng; Bastian, Robert W; Perlmutter, Joel S; Racette, Brad A; Tabbal, Samer D; Karimi, Morvarid; Paniello, Randal C; Blitzer, Andrew; Batish, Sat Dev; Wszolek, Zbigniew K; Uitti, Ryan J; Hedera, Peter; Simon, David K; Tarsy, Daniel; Truong, Daniel D; Frei, Karen P; Pfeiffer, Ronald F; Gong, Suzhen; Zhao, Yu; LeDoux, Mark S

    2009-03-11

    Although the c.904_906delGAG mutation in Exon 5 of TOR1A typically manifests as early-onset generalized dystonia, DYT1 dystonia is genetically and clinically heterogeneous. Recently, another Exon 5 mutation (c.863G>A) has been associated with early-onset generalized dystonia and some DeltaGAG mutation carriers present with late-onset focal dystonia. The aim of this study was to identify TOR1A Exon 5 mutations in a large cohort of subjects with mainly non-generalized primary dystonia. High resolution melting (HRM) was used to examine the entire TOR1A Exon 5 coding sequence in 1014 subjects with primary dystonia (422 spasmodic dysphonia, 285 cervical dystonia, 67 blepharospasm, 41 writer's cramp, 16 oromandibular dystonia, 38 other primary focal dystonia, 112 segmental dystonia, 16 multifocal dystonia, and 17 generalized dystonia) and 250 controls (150 neurologically normal and 100 with other movement disorders). Diagnostic sensitivity and specificity were evaluated in an additional 8 subjects with known DeltaGAG DYT1 dystonia and 88 subjects with DeltaGAG-negative dystonia. HRM of TOR1A Exon 5 showed high (100%) diagnostic sensitivity and specificity. HRM was rapid and economical. HRM reliably differentiated the TOR1A DeltaGAG and c.863G>A mutations. Melting curves were normal in 250/250 controls and 1012/1014 subjects with primary dystonia. The two subjects with shifted melting curves were found to harbor the classic DeltaGAG deletion: 1) a non-Jewish Caucasian female with childhood-onset multifocal dystonia and 2) an Ashkenazi Jewish female with adolescent-onset spasmodic dysphonia. First, HRM is an inexpensive, diagnostically sensitive and specific, high-throughput method for mutation discovery. Second, Exon 5 mutations in TOR1A are rarely associated with non-generalized primary dystonia.

  19. High-throughput mutational analysis of TOR1A in primary dystonia

    Directory of Open Access Journals (Sweden)

    Truong Daniel D

    2009-03-01

    Full Text Available Abstract Background Although the c.904_906delGAG mutation in Exon 5 of TOR1A typically manifests as early-onset generalized dystonia, DYT1 dystonia is genetically and clinically heterogeneous. Recently, another Exon 5 mutation (c.863G>A has been associated with early-onset generalized dystonia and some ΔGAG mutation carriers present with late-onset focal dystonia. The aim of this study was to identify TOR1A Exon 5 mutations in a large cohort of subjects with mainly non-generalized primary dystonia. Methods High resolution melting (HRM was used to examine the entire TOR1A Exon 5 coding sequence in 1014 subjects with primary dystonia (422 spasmodic dysphonia, 285 cervical dystonia, 67 blepharospasm, 41 writer's cramp, 16 oromandibular dystonia, 38 other primary focal dystonia, 112 segmental dystonia, 16 multifocal dystonia, and 17 generalized dystonia and 250 controls (150 neurologically normal and 100 with other movement disorders. Diagnostic sensitivity and specificity were evaluated in an additional 8 subjects with known ΔGAG DYT1 dystonia and 88 subjects with ΔGAG-negative dystonia. Results HRM of TOR1A Exon 5 showed high (100% diagnostic sensitivity and specificity. HRM was rapid and economical. HRM reliably differentiated the TOR1A ΔGAG and c.863G>A mutations. Melting curves were normal in 250/250 controls and 1012/1014 subjects with primary dystonia. The two subjects with shifted melting curves were found to harbor the classic ΔGAG deletion: 1 a non-Jewish Caucasian female with childhood-onset multifocal dystonia and 2 an Ashkenazi Jewish female with adolescent-onset spasmodic dysphonia. Conclusion First, HRM is an inexpensive, diagnostically sensitive and specific, high-throughput method for mutation discovery. Second, Exon 5 mutations in TOR1A are rarely associated with non-generalized primary dystonia.

  20. Phosphatidic acid enhances mTOR signaling and resistance exercise induced hypertrophy.

    Science.gov (United States)

    Joy, Jordan M; Gundermann, David M; Lowery, Ryan P; Jäger, Ralf; McCleary, Sean A; Purpura, Martin; Roberts, Michael D; Wilson, Stephanie Mc; Hornberger, Troy A; Wilson, Jacob M

    2014-01-01

    The lipid messenger phosphatidic acid (PA) plays a critical role in the stimulation of mTOR signaling. However, the mechanism by which PA stimulates mTOR is currently unknown. Therefore, the purpose of this study was to compare the effects of various PA precursors and phospholipids on their ability to stimulate mTOR signaling and its ability to augment resistance training-induced changes in body composition and performance. In phase one, C2C12 myoblasts cells were stimulated with different phospholipids and phospholipid precursors derived from soy and egg sources. The ratio of phosphorylated p70 (P-p70-389) to total p70 was then used as readout for mTOR signaling. In phase two, resistance trained subjects (n = 28, 21 ± 3 years, 77 ± 4 kg, 176 ± 9 cm) consumed either 750 mg PA daily or placebo and each took part in an 8 week periodized resistance training program. In phase one, soy-phosphatidylserine, soy-Lyso-PA, egg-PA, and soy-PA stimulated mTOR signaling, and the effects of soy-PA (+636%) were significantly greater than egg-PA (+221%). In phase two, PA significantly increased lean body mass (+2.4 kg), cross sectional area (+1.0 cm), and leg press strength (+51.9 kg) over placebo. PA significantly activates mTOR and significantly improved responses in skeletal muscle hypertrophy, lean body mass, and maximal strength to resistance exercise.

  1. α1A-Adrenoceptors activate mTOR signalling and glucose uptake in cardiomyocytes.

    Science.gov (United States)

    Sato, Masaaki; Evans, Bronwyn A; Sandström, Anna L; Chia, Ling Yeong; Mukaida, Saori; Thai, Bui San; Nguyen, Anh; Lim, Linzi; Tan, Christina Y R; Baltos, Jo-Anne; White, Paul J; May, Lauren T; Hutchinson, Dana S; Summers, Roger J; Bengtsson, Tore

    2018-02-01

    The capacity of G protein-coupled receptors to modulate mechanistic target of rapamycin (mTOR) activity is a newly emerging paradigm with the potential to link cell surface receptors with cell survival. Cardiomyocyte viability is linked to signalling pathways involving Akt and mTOR, as well as increased glucose uptake and utilization. Our aim was to determine whether the α 1A -adrenoceptor (AR) couples to these protective pathways, and increased glucose uptake. We characterised α 1A -AR signalling in CHO-K1 cells co-expressing the human α 1A -AR and GLUT4 (CHOα 1A GLUT4myc) and in neonatal rat ventricular cardiomyocytes (NRVM), and measured glucose uptake, intracellular Ca 2+ mobilization, and phosphorylation of mTOR, Akt, 5' adenosine monophosphate-activated kinase (AMPK) and S6 ribosomal protein (S6rp). In both systems, noradrenaline and the α 1A -AR selective agonist A61603 stimulated glucose uptake by parallel pathways involving mTOR and AMPK, whereas another α 1 -AR agonist oxymetazoline increased glucose uptake predominantly by mTOR. All agonists promoted phosphorylation of mTOR at Ser2448 and Ser2481, indicating activation of both mTORC1 and mTORC2, but did not increase Akt phosphorylation. In CHOα 1A GLUT4myc cells, siRNA directed against rictor but not raptor suppressed α 1A -AR mediated glucose uptake. We have thus identified mTORC2 as a key component in glucose uptake stimulated by α 1A -AR agonists. Our findings identify a novel link between the α 1A -AR, mTORC2 and glucose uptake, that have been implicated separately in cardiomyocyte survival. Our studies provide an improved framework for examining the utility of α 1A -AR selective agonists as tools in the treatment of cardiac dysfunction. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  2. mTOR inhibition sensitizes human hepatocellular carcinoma cells to resminostat

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Xingang, E-mail: pengxinggang26@sina.com [Department of Emergency General Surgery, The Affiliated Hospital of Qingdao University, Qingdao (China); Zhang, Donghui, E-mail: zhangdonghuiyx@sina.com [Department of Infectious Disease, Linyi People’s Hospital, Linyi (China); Li, Zhengling, E-mail: lizhenglingzz@sina.com [Department of Nursing, Tengzhou Central People’s Hospital, Tengzhou (China); Fu, Meili, E-mail: fumeilidrlinyi@tom.com [Department of Infectious Disease, Linyi People’s Hospital, Linyi (China); Liu, Haiyan, E-mail: liuhaiyanlinyi5@sina.com [Department of Nursing, Linyi People’s Hospital, Linyi (China)

    2016-09-02

    Histone deacetylases (HDACs) hyper-activity in hepatocellular carcinoma (HCC) is often associated with patients’ poor prognosis. Our previous study has shown that resminostat, a novel HDAC inhibitor (HDACi), activated mitochondrial permeability transition pore (mPTP)-dependent apoptosis pathway in HCC cells. Here we explored the potential resminostat resistance factor by focusing on mammalian target of rapamycin (mTOR). We showed that AZD-2014, a novel mTOR kinase inhibitor, potentiated resminostat-induced cytotoxicity and proliferation inhibition in HCC cells. Molecularly, AZD-2014 enhanced resminostat-induced mPTP apoptosis pathway activation in HCC cells. Inhibition of this apoptosis pathway, by the caspase-9 specific inhibitor Ac-LEHD-CHO, the mPTP blockers (sanglifehrin A/cyclosporine A), or by shRNA-mediated knockdown of mPTP component cyclophilin-D (Cyp-D), significantly attenuated resminostat plus AZD-2014-induced cytotoxicity and apoptosis in HCC cells. Significantly, mTOR shRNA knockdown or kinase-dead mutation (Asp-2338-Ala) also sensitized HCC cells to resminostat, causing profound cytotoxicity and apoptosis induction. Together, these results suggest that mTOR could be a primary resistance factor of resminostat. Targeted inhibition of mTOR may thus significantly sensitize HCC cells to resminostat. - Highlights: • AZD-2014 potentiates resminostat’s cytotoxicity against HCC cells. • AZD-2014 facilitates resminostat-induced HCC cell apoptosis. • AZD-2014 augments resminostat-induced mitochondrial apoptosis pathway activation. • mTOR shRNA or kinase-dead mutation significantly sensitizes HCC cells to resminostat.

  3. mTOR in breast cancer: differential expression in triple-negative and non-triple-negative tumors.

    LENUS (Irish Health Repository)

    Walsh, S

    2012-04-01

    Triple-negative breast cancer (TNBC) is defined by the absence of estrogen receptors (ER), progesterone receptors (PR) and overexpression of HER2. Targeted therapy is currently unavailable for this subgroup of breast cancer patients. mTOR controls cancer cell growth, survival and invasion and is thus a potential target for the treatment of patients with TNBC. Using immunohistochemistry, mTOR and p-mTOR were measured in 89 TNBCs and 99 non-TNBCs. While mTOR expression was confined to tumor cell cytoplasm, p-mTOR staining was located in the nucleus, perinuclear area and in the cytoplasm. Potentially important, was our finding that nuclear p-mTOR was found more frequently in triple-negative than non triple-negative cancers (p < 0.001). These results suggest that mTOR may play a more important role in the progression of TNBC compared to non-TNBC. Based on these findings, we conclude that mTOR may be a new target for the treatment of triple-negative breast cancer.

  4. Ectopic expression of Arabidopsis Target of Rapamycin (AtTOR) improves water-use efficiency and yield potential in rice

    Science.gov (United States)

    Bakshi, Achala; Moin, Mazahar; Kumar, M. Udaya; Reddy, Aramati Bindu Madhava; Ren, Maozhi; Datla, Raju; Siddiq, E. A.; Kirti, P. B.

    2017-02-01

    The target of Rapamycin (TOR) present in all eukaryotes is a multifunctional protein, regulating growth, development, protein translation, ribosome biogenesis, nutrient, and energy signaling. In the present study, ectopic expression of TOR gene of Arabidopsis thaliana in a widely cultivated indica rice resulted in enhanced plant growth under water-limiting conditions conferring agronomically important water-use efficiency (WUE) trait. The AtTOR high expression lines of rice exhibited profuse tillering, increased panicle length, increased plant height, high photosynthetic efficiency, chlorophyll content and low ∆13C. Δ13C, which is inversely related to high WUE, was as low as 17‰ in two AtTOR high expression lines. These lines were also insensitive to the ABA-mediated inhibition of seed germination. The significant upregulation of 15 stress-specific genes in high expression lines indicates their contribution to abiotic stress tolerance. The constitutive expression of AtTOR is also associated with significant transcriptional upregulation of putative TOR complex-1 components, OsRaptor and OsLST8. Glucose-mediated transcriptional activation of AtTOR gene enhanced lateral root formation. Taken together, our findings indicate that TOR, in addition to its multiple cellular functions, also plays an important role in response to abiotic stress and potentially enhances WUE and yield related attributes.

  5. Molecular characterization of the Akt-TOR signaling pathway in rainbow trout: potential role in muscle growth/degradation

    Science.gov (United States)

    The Akt-TOR signaling pathway plays a key role in cellular metabolism and muscle growth. Hormone, nutrition and stress factors affect the Akt-TOR pathway by regulating gene transcription, protein synthesis and degradation. In addition, we previously showed that energetic demands elevate during vit...

  6. Cord Blood Cells Responses to IL2, IL7 and IL15 Cytokines for mTOR Expression.

    Science.gov (United States)

    Mohammadian, Anahita; Naderali, Elahe; Mohammadi, Seyedeh Momeneh; Movasaghpour, Aliakbar; Valipour, Behnaz; Nouri, Mohammad; Nozad Charoudeh, Hojjatollah

    2017-04-01

    Purpose: Mammalian target of rapamycin (mTOR)is important in hematopoiesis and affect cell growth,differentiation and survival. Although previous studies were identified the effect of cytokines on the mononuclear cells development however the cytokines effect on mTOR in cord blood mononuclear cells was unclear. The aim of this study was to evaluate mTOR expression in cord blood mononuclear and cord blood stem cells (CD34+ cells) in culture conditions for lymphoid cell development. Methods: Isolation of The mononuclear cells (MNCs) from umbilical cord blood were done with use of Ficollpaque density gradient. We evaluated cultured cord blood mononuclear and CD34+ cells in presece of IL2, IL7 and IL15 at distinct time points during 21 days by using flow cytometry. In this study, we presented the role of IL2, IL7 and IL15 on the expression of mTOR in cord blood cells. Results: mTOR expression were increased in peresence of IL2, IL7 and IL15 in day 14 and afterword reduced. However in persence of IL2 and IL15 expression of mTOR significantly reduced. mTOR expression in CD34+ cells decreased significantly from day7 to day 21 in culture. Conclusion: cytokines play important role in mTOR expression during hematopoiesis and development of cord blood mononuclear cells.

  7. Hypothalamic roles of mTOR complex I: Integration of nutrient and hormone signals to regulate energy homeostasis

    Science.gov (United States)

    Mammalian or mechanistic target of rapamycin (mTOR) senses nutrient, energy, and hormone signals to regulate metabolism and energy homeostasis. mTOR activity in the hypothalamus, which is associated with changes in energy status, plays a critical role in the regulation of food intake and body weight...

  8. Complicaciones torácicas en un paciente con luxación subclavicular del hombro

    OpenAIRE

    Arenas Planelles, Antonio; Alberdi Ibañez, I.; Pampliega Martínez, T.; Álvarez López, A.; Iglesias Marchite, J.

    1994-01-01

    Se presenta una paciente de 88 años de edad con una luxación subclavicular de hombro derecho y un traumatismo torácico asociado que incluía fractura de las tres primeras costillas y hemotórax. El traumatismo torácico parecía estar muy estrechamente relacionado con la luxación glenohumeral. El tratamiento de la luxación se efectuó mediante reducción cerrada e inmovilización con vendaje de Gilchrist. El traumatismo del hemitórax derecho requirió toracocentesis en 2 ocasiones e in...

  9. Finding a better drug for epilepsy: The mTOR pathway as an antiepileptogenic target

    Science.gov (United States)

    Galanopoulou, Aristea S.; Gorter, Jan A.; Cepeda, Carlos

    2012-01-01

    Summary The mTOR signaling pathway regulates cell growth, differentiation, proliferation and metabolism. Loss of function mutations in upstream regulators of mTOR have been highly associated with dysplasias, epilepsy and neurodevelopmental disorders. These include tuberous sclerosis, which is due to mutations in TSC1 or TSC2 genes, mutations in phosphatase and tensin homolog (PTEN) as in Cowden syndrome, polyhydramnios, megalencephaly, symptomatic epilepsy syndrome (PMSE) due to mutations in the STE20-related kinase adaptor alpha (STRADalpha), and neurofibromatosis type 1 attributed to neurofibromin 1 mutations. Inhibition of the mTOR pathway with rapamycin may prevent epilepsy and improve the underlying pathology in mouse models with disrupted mTOR signaling, due to PTEN or TSC mutations. However the timing and duration of its administration appear critical in defining the seizure and pathology-related outcomes. Rapamycin application in human cortical slices from patients with cortical dysplasias reduces the 4-aminopyridine induced oscillations. In the multiple-hit model of infantile spasms, pulse high dose rapamycin administration can reduce the cortical overactivation of the mTOR pathway, suppresses spasms and has disease-modifying effects by partially improving cognitive deficits. In post-status epilepticus models of temporal lobe epilepsy, rapamycin may ameliorate the development of epilepsy-related pathology and reduce the expression of spontaneous seizures, but its effects depend on the timing and duration of administration, and possibly the model used. The observed recurrence of seizures and epilepsy-related pathology after rapamycin discontinuation suggests the need for continuous administration to maintain the benefit. However, the use of pulse administration protocols may be useful in certain age-specific epilepsy syndromes, like infantile spasms, whereas repetitive pulse rapamycin protocols may suffice to sustain a long-term benefit in genetic disorders

  10. FK866-induced NAMPT inhibition activates AMPK and downregulates mTOR signaling in hepatocarcinoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Susanne, E-mail: Susanne.Schuster@medizin.uni-leipzig.de [Center for Pediatric Research Leipzig, University Hospital for Children and Adolescents, Faculty of Medicine, University of Leipzig, Liebigstr. 21, 04103 Leipzig (Germany); Penke, Melanie; Gorski, Theresa [Center for Pediatric Research Leipzig, University Hospital for Children and Adolescents, Faculty of Medicine, University of Leipzig, Liebigstr. 21, 04103 Leipzig (Germany); Gebhardt, Rolf [Institute of Biochemistry, Faculty of Medicine, University of Leipzig, Johannisallee 30, 04103 Leipzig (Germany); Weiss, Thomas S. [Children' s University Hospital, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg (Germany); Kiess, Wieland; Garten, Antje [Center for Pediatric Research Leipzig, University Hospital for Children and Adolescents, Faculty of Medicine, University of Leipzig, Liebigstr. 21, 04103 Leipzig (Germany)

    2015-03-06

    Background: Nicotinamide phosphoribosyltransferase (NAMPT) is the key enzyme of the NAD salvage pathway starting from nicotinamide. Cancer cells have an increased demand for NAD due to their high proliferation and DNA repair rate. Consequently, NAMPT is considered as a putative target for anti-cancer therapies. There is evidence that AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) become dysregulated during the development of hepatocellular carcinoma (HCC). Here, we investigated the effects of NAMPT inhibition by its specific inhibitor FK866 on the viability of hepatocarcinoma cells and analyzed the effects of FK866 on the nutrient sensor AMPK and mTOR complex1 (mTORC1) signaling. Results: FK866 markedly decreased NAMPT activity and NAD content in hepatocarcinoma cells (Huh7 cells, Hep3B cells) and led to delayed ATP reduction which was associated with increased cell death. These effects could be abrogated by administration of nicotinamide mononucleotide (NMN), the enzyme product of NAMPT. Our results demonstrated a dysregulation of the AMPK/mTOR pathway in hepatocarcinoma cells compared to non-cancerous hepatocytes with a higher expression of mTOR and a lower AMPKα activation in hepatocarcinoma cells. We found that NAMPT inhibition by FK866 significantly activated AMPKα and inhibited the activation of mTOR and its downstream targets p70S6 kinase and 4E-BP1 in hepatocarcinoma cells. Non-cancerous hepatocytes were less sensitive to FK866 and did not show changes in AMPK/mTOR signaling after FK866 treatment. Conclusion: Taken together, these findings reveal an important role of the NAMPT-mediated NAD salvage pathway in the energy homeostasis of hepatocarcinoma cells and suggest NAMPT inhibition as a potential treatment option for HCC. - Highlights: • FK866 increases cell death in p53-deficient hepatocarcinoma cells. • AMPK/mTOR signaling is dysregulated in hepatocarcinoma cells. • FK866-induced NAMPT inhibition activates AMPK

  11. High-throughput mutational analysis of TOR1A in primary dystonia

    OpenAIRE

    Truong Daniel D; Tarsy Daniel; Simon David K; Hedera Peter; Uitti Ryan J; Wszolek Zbigniew K; Batish Sat; Blitzer Andrew; Paniello Randal C; Karimi Morvarid; Tabbal Samer D; Racette Brad A; Perlmutter Joel S; Bastian Robert W; Xiao Jianfeng

    2009-01-01

    Abstract Background Although the c.904_906delGAG mutation in Exon 5 of TOR1A typically manifests as early-onset generalized dystonia, DYT1 dystonia is genetically and clinically heterogeneous. Recently, another Exon 5 mutation (c.863G>A) has been associated with early-onset generalized dystonia and some ΔGAG mutation carriers present with late-onset focal dystonia. The aim of this study was to identify TOR1A Exon 5 mutations in a large cohort of subjects with mainly non-generalized primary dy...

  12. Attenuation of trace organic compounds (TOrCs) in bioelectrochemical systems.

    Science.gov (United States)

    Werner, Craig M; Hoppe-Jones, Christiane; Saikaly, Pascal E; Logan, Bruce E; Amy, Gary L

    2015-04-15

    Microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) are two types of microbial bioelectrochemical systems (BESs) that use microorganisms to convert chemical energy in wastewaters into useful energy products such as (bio)electricity (MFC) or hydrogen gas (MEC). These two systems were evaluated for their capacity to attenuate trace organic compounds (TOrCs), commonly found in municipal wastewater, under closed circuit (current generation) and open circuit (no current generation) conditions, using acetate as the carbon source. A biocide was used to evaluate attenuation in terms of biotransformation versus sorption. The difference in attenuation observed before and after addition of the biocide represented biotransformation, while attenuation after addition of a biocide primarily indicated sorption. Attenuation of TOrCs was similar in MFCs and MECs for eight different TOrCs, except for caffeine and trimethoprim where slightly higher attenuation was observed in MECs. Electric current generation did not enhance attenuation of the TOrCs except for caffeine, which showed slightly higher attenuation under closed circuit conditions in both MFCs and MECs. Substantial sorption of the TOrCs occurred to the biofilm-covered electrodes, but no consistent trend could be identified regarding the physico-chemical properties of the TOrCs tested and the extent of sorption. The octanol-water distribution coefficient at pH 7.4 (log DpH 7.4) appeared to be a reasonable predictor for sorption of some of the compounds (carbamazepine, atrazine, tris(2-chloroethyl) phosphate and diphenhydramine) but not for others (N,N-Diethyl-meta-toluamide). Atenolol also showed high levels of sorption despite being the most hydrophilic in the suite of compounds studied (log DpH 7.4 = -1.99). Though BESs do not show any inherent advantages over conventional wastewater treatment, with respect to TOrC removal, overall removals in BESs are similar to that reported for conventional wastewater

  13. Finding a better drug for epilepsy: the mTOR pathway as an antiepileptogenic target.

    Science.gov (United States)

    Galanopoulou, Aristea S; Gorter, Jan A; Cepeda, Carlos

    2012-07-01

    The mammalian target of rapamycin (mTOR) signaling pathway regulates cell growth, differentiation, proliferation, and metabolism. Loss-of-function mutations in upstream regulators of mTOR have been highly associated with dysplasias, epilepsy, and neurodevelopmental disorders. These include tuberous sclerosis, which is due to mutations in TSC1 or TSC2 genes; mutations in phosphatase and tensin homolog (PTEN) as in Cowden syndrome, polyhydramnios, megalencephaly, symptomatic epilepsy syndrome (PMSE) due to mutations in the STE20-related kinase adaptor alpha (STRADalpha); and neurofibromatosis type 1 attributed to neurofibromin 1 mutations. Inhibition of the mTOR pathway with rapamycin may prevent epilepsy and improve the underlying pathology in mouse models with disrupted mTOR signaling, due to PTEN or TSC mutations. However the timing and duration of its administration appear critical in defining the seizure and pathology-related outcomes. Rapamycin application in human cortical slices from patients with cortical dysplasias reduces the 4-aminopyridine-induced oscillations. In the multiple-hit model of infantile spasms, pulse high-dose rapamycin administration can reduce the cortical overactivation of the mTOR pathway, suppresses spasms, and has disease-modifying effects by partially improving cognitive deficits. In post-status epilepticus models of temporal lobe epilepsy, rapamycin may ameliorate the development of epilepsy-related pathology and reduce the expression of spontaneous seizures, but its effects depend on the timing and duration of administration, and possibly the model used. The observed recurrence of seizures and epilepsy-related pathology after rapamycin discontinuation suggests the need for continuous administration to maintain the benefit. However, the use of pulse administration protocols may be useful in certain age-specific epilepsy syndromes, like infantile spasms, whereas repetitive-pulse rapamycin protocols may suffice to sustain a long

  14. Sensitivity of Saccharomyces cerevisiae defective in TOR signaling pathway to carbonyl/oxidative stress

    Directory of Open Access Journals (Sweden)

    Valishkevych B. V.

    2014-09-01

    Full Text Available Aim. To investigate the influence of carbonyl/oxidative stress induced by glyoxal, methylglyoxal and hydrogen peroxide on the survival of Saccharomyces cerevisiae, defective for different parts of TOR- signaling pathway, grown on glucose or fructose. Methods. The assessment of number of colony-forming units to determine the yeast reproductive ability. Results. It was shown that at certain concentrations the mentioned above toxicants caused an increase in yeast survival, indicating the hormetic effect. Conclusions. The TOR signaling pathway is involved in the hormetic effect, but it is specific for each strain and depends on the type of carbohydrate in the incubation medium.

  15. Experiencia del dolor torácico en la mujer con infarto del miocardio

    OpenAIRE

    EILLEN MARYIBE MILLÁN; LUZ PATRICIA DÍAZ H

    2009-01-01

    Se presentan los resultados de la investigación " La experiencia del dolor torácico en la mujer con infarto agudo del miocardio" . Es un estudio cualitativo fenomenológico, que indagó sobre la experiencia del dolor torácico de la mujer que ha sufrido un infarto agudo del miocardio. Se realizó con nueve mujeres cuyo promedio de edad era de 52 años, en su mayoría amas de casa, entrevistadas personalmente por la investigadora. Se utilizó el sistema de entrevista a profundidad, siendo la base fun...

  16. PI3K/AKT/mTOR: role in breast cancer progression, drug resistance, and treatment.

    Science.gov (United States)

    Guerrero-Zotano, Angel; Mayer, Ingrid A; Arteaga, Carlos L

    2016-12-01

    Anti-cancer cancer-targeted therapies are designed to exploit a particular vulnerability in the tumor, which in most cases results from its dependence on an oncogene and/or loss of a tumor suppressor. Mutations in the phosphoinositide 3-kinase (PI3K)/AKT/mTOR pathway are freqcuently found in breast cancers and associated with cellular transformation, tumorigenesis, cancer progression, and drug resistance. Several drugs targeting PI3K/ATK/mTOR are currently in clinical trials, mainly in combination with endocrine therapy and anti-HER2 therapy. These drugs are the focus of this review.

  17. The granite tors of Dartmoor, Southwest England: rapid and recent emergence revealed by Late Pleistocene cosmogenic apparent exposure ages

    Science.gov (United States)

    Gunnell, Yanni; Jarman, David; Braucher, Régis; Calvet, Marc; Delmas, Magali; Leanni, Laetitia; Bourlès, Didier; Arnold, Maurice; Aumaître, Georges; Keddaouche, Karim

    2013-02-01

    Dartmoor, in SW England, is a classic periglaciated granite upland adorned with a population of over 150 tors. The origin of the tors has been controversial, but their emergence by differentiation after stripping of regolith during Pleistocene cold phases is accepted. However, their actual age has been unknown, with possible scenarios ranging from preservation since the early Middle Pleistocene to relatively short-lived landforms in a maritime climate with high denudation rates. The latter is now supported by 32 cosmogenic surface exposure dates from 28 tors across the whole upland. The distribution of apparent 10Be ages peaks strongly in the Middle Devensian (36-50 ka), which with corrections for weathering and limited ice shielding could be interpreted as Early Devensian. These ages are much younger than those found for three glacially unmodified Cairngorms tors, and somewhat younger even than glacially modified Cairngorms tors. The dates show little spatial variation. Although an ice cap has now been modelled in the heart of northern Dartmoor, tors here are of median age, suggesting that ice cover sufficient to shield tors from incoming radiation was of short duration. The few younger tor ages support the idea of continuing landform instability across the landscape, with weathering flakes redeveloping soon after inferred loss of top pillows by gelifraction or gravitational toppling. The few older tor ages have no systematic explanation, and may indicate inheritance from an earlier cycle of bedrock near-exposure. Since most tors are modest in height (typically 2-5 m), volumetrically insignificant, and often in advanced stages of disintegration, the general impression is that they are evanescent features, which emerge and quickly disappear during every Pleistocene climatic downturn. Tor populations may thus flicker across the landscape rather randomly over the Quaternary. The remarkably consistent age of the present tor population could be associated with a

  18. The El Tor Biotype of Vibrio cholerae Exhibits a Growth Advantage in the Stationary Phase in Mixed Cultures with the Classical Biotype▿

    OpenAIRE

    Pradhan, Subhra; Baidya, Amit K.; Ghosh, Amalendu; Paul, Kalidas; Chowdhury, Rukhsana

    2009-01-01

    Vibrio cholerae strains of the O1 serogroup that typically cause epidemic cholera can be classified into two biotypes, classical and El Tor. The El Tor biotype emerged in 1961 and subsequently displaced the classical biotype as a cause of cholera throughout the world. In this study we demonstrate that when strains of the El Tor and classical biotypes were cocultured in standard LB medium, the El Tor strains clearly had a competitive growth advantage over the classical biotype starting from th...

  19. The dual targeting of insulin and insulin-like growth factor 1 receptor enhances the mTOR inhibitor-mediated antitumor efficacy in hepatocellular carcinoma

    NARCIS (Netherlands)

    C. Pivonello (Claudia); M. Negri (Mariarosaria); M.C. de Martino (Maria Cristina); M. Napolitano (Maria); C. de Angelis (Cristina); D.P. Provvisiero (Donatella Paola); G. Cuomo (Gaia); R.S. Auriemma (Renata Simona); C. Simeoli (Chiara); F. Izzo (Francesco); A. Colao (Annamaria); L.J. Hofland (Leo); R. Pivonello (Rosario)

    2016-01-01

    textabstractDeregulation of mTOR and IGF pathways is frequent in hepatocellular carcinoma (HCC), thus mTOR and IGF1R represent suitable therapeutic targets in HCC. The aim of this study was to evaluate the effects of mTOR inhibitors (mTORi) and OSI-906, blocker of IGF1R/IR, on HCC cell

  20. mTOR direct interactions with Rheb-GTPase and raptor: sub-cellular localization using fluorescence lifetime imaging

    Directory of Open Access Journals (Sweden)

    Yadav Rahul B

    2013-01-01

    Full Text Available Abstract Background The mammalian target of rapamycin (mTOR signalling pathway has a key role in cellular regulation and several diseases. While it is thought that Rheb GTPase regulates mTOR, acting immediately upstream, while raptor is immediately downstream of mTOR, direct interactions have yet to be verified in living cells, furthermore the localisation of Rheb has been reported to have only a cytoplasmic cellular localization. Results In this study a cytoplasmic as well as a significant sub-cellular nuclear mTOR localization was shown , utilizing green and red fluorescent protein (GFP and DsRed fusion and highly sensitive single photon counting fluorescence lifetime imaging microscopy (FLIM of live cells. The interaction of the mTORC1 components Rheb, mTOR and raptor, tagged with EGFP/DsRed was determined using fluorescence energy transfer-FLIM. The excited-state lifetime of EGFP-mTOR of ~2400 ps was reduced by energy transfer to ~2200 ps in the cytoplasm and to 2000 ps in the nucleus when co-expressed with DsRed-Rheb, similar results being obtained for co-expressed EGFP-mTOR and DsRed-raptor. The localization and distribution of mTOR was modified by amino acid withdrawal and re-addition but not by rapamycin. Conclusions The results illustrate the power of GFP-technology combined with FRET-FLIM imaging in the study of the interaction of signalling components in living cells, here providing evidence for a direct physical interaction between mTOR and Rheb and between mTOR and raptor in living cells for the first time.

  1. Transient mTOR inhibition facilitates continuous growth of liver tumors by modulating the maintenance of CD133+ cell populations.

    Directory of Open Access Journals (Sweden)

    Zhaojuan Yang

    Full Text Available The mammalian target of the rapamycin (mTOR pathway, which drives cell proliferation, is frequently hyperactivated in a variety of malignancies. Therefore, the inhibition of the mTOR pathway has been considered as an appropriate approach for cancer therapy. In this study, we examined the roles of mTOR in the maintenance and differentiation of cancer stem-like cells (CSCs, the conversion of conventional cancer cells to CSCs and continuous tumor growth in vivo. In H-Ras-transformed mouse liver tumor cells, we found that pharmacological inhibition of mTOR with rapamycin greatly increased not only the CD133+ populations both in vitro and in vivo but also the expression of stem cell-like genes. Enhancing mTOR activity by over-expressing Rheb significantly decreased CD133 expression, whereas knockdown of the mTOR yielded an opposite effect. In addition, mTOR inhibition severely blocked the differentiation of CD133+ to CD133- liver tumor cells. Strikingly, single-cell culture experiments revealed that CD133- liver tumor cells were capable of converting to CD133+ cells and the inhibition of mTOR signaling substantially promoted this conversion. In serial implantation of tumor xenografts in nude BALB/c mice, the residual tumor cells that were exposed to rapamycin in vivo displayed higher CD133 expression and had increased secondary tumorigenicity compared with the control group. Moreover, rapamycin treatment also enhanced the level of stem cell-associated genes and CD133 expression in certain human liver tumor cell lines, such as Huh7, PLC/PRC/7 and Hep3B. The mTOR pathway is significantly involved in the generation and the differentiation of tumorigenic liver CSCs. These results may be valuable for the design of more rational strategies to control clinical malignant HCC using mTOR inhibitors.

  2. Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

    Science.gov (United States)

    Dengo-Baloi, Liliana Candida; Semá-Baltazar, Cynthia Amino; Manhique, Lena Vania; Chitio, Jucunu Elias; Inguane, Dorteia Luísa; Langa, José Paulo

    2017-01-01

    Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique. The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics. We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09), Memba (01), Tete City (08), Moatize (01), Morrumbala (01) districts, City of Quelimane (01), Lichinga (06) and Nampula (86) districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute) 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health. Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53) to Trimethoprim-, being 100% (54/54) for Ampicillin, 99% (72/74) for Nalidixic Acid, 97% (64/66) to Chloramphenicol, 95% (42/44) for Nitrofurantoin and (19/20) Cotrimoxazole, 83% (80

  3. Magnetic susceptibilities of minerals

    Science.gov (United States)

    Rosenblum, Sam; Brownfield, I.K.

    2000-01-01

    Magnetic separation of minerals is a topic that is seldom reported in the literature for two reasons. First, separation data generally are byproducts of other projects; and second, this study requires a large amount of patience and is unusually tedious. Indeed, we suspect that most minerals probably are never investigated for this property. These data are timesaving for mineralogists who concentrate mono-mineralic fractions for chemical analysis, age dating, and for other purposes. The data can certainly be used in the ore-beneficiation industries. In some instances, magnetic-susceptibility data may help in mineral identification, where other information is insufficient. In past studies of magnetic separation of minerals, (Gaudin and Spedden, 1943; Tille and Kirkpatrick, 1956; Rosenblum, 1958; Rubinstein and others, 1958; Flinter, 1959; Hess, 1959; Baker, 1962; Meric and Peyre, 1963; Rojas and others, 1965; and Duchesne, 1966), the emphasis has been on the ferromagnetic and paramagnetic ranges of extraction. For readers interested in the history of magnetic separation of minerals, Krumbein and Pettijohn (1938, p. 344-346) indicated nine references back to 1848. The primary purpose of this paper is to report the magnetic-susceptibility data on as many minerals as possible, similar to tables of hardness, specific gravity, refractive indices, and other basic physical properties of minerals. A secondary purpose is to demonstrate that the total and best extraction ranges are influenced by the chemistry of the minerals. The following notes are offered to help avoid problems in separating a desired mineral concentrate from mixtures of mineral grains.

  4. Alcohol increases hypnotic susceptibility.

    Science.gov (United States)

    Semmens-Wheeler, Rebecca; Dienes, Zoltán; Duka, Theodora

    2013-09-01

    One approach to hypnosis suggests that for hypnotic experience to occur frontal lobe activity must be attenuated. For example, cold control theory posits that a lack of awareness of intentions is responsible for the experience of involuntariness and/or the subjective reality of hypnotic suggestions. The mid-dorso-lateral prefrontal cortex and the ACC are candidate regions for such awareness. Alcohol impairs frontal lobe executive function. This study examined whether alcohol affects hypnotisability. We administered 0.8 mg/kg of alcohol or a placebo to 32 medium susceptible participants. They were subsequently hypnotised and given hypnotic suggestions. All participants believed they had received some alcohol. Participants in the alcohol condition were more susceptible to hypnotic suggestions than participants in the placebo condition. Impaired frontal lobe activity facilitates hypnotic responding, which supports theories postulating that attenuation of executive function facilitates hypnotic response, and contradicts theories postulating that hypnotic response involves enhanced inhibitory, attentional or other executive function. Copyright © 2013. Published by Elsevier Inc.

  5. Cu-free 1,3-dipolar cycloaddition click reactions to form isoxazole linkers in chelating ligands for fac-[M(I)(CO)3]+ centers (M = Re, 99mTc).

    Science.gov (United States)

    Bottorff, Shalina C; Kasten, Benjamin B; Stojakovic, Jelena; Moore, Adam L; MacGillivray, Leonard R; Benny, Paul D

    2014-02-17

    Isoxazole ring formation was examined as a potential Cu-free alternative click reaction to Cu(I)-catalyzed alkyne/azide cycloaddition. The isoxazole reaction was explored at macroscopic and radiotracer concentrations with the fac-[M(I)(CO)3](+) (M = Re, (99m)Tc) core for use as a noncoordinating linker strategy between covalently linked molecules. Two click assembly methods (click, then chelate and chelate, then click) were examined to determine the feasibility of isoxazole ring formation with either alkyne-functionalized tridentate chelates or their respective fac-[M(I)(CO)3](+) complexes with a model nitrile oxide generator. Macroscale experiments, alkyne-functionalized chelates, or Re complexes indicate facile formation of the isoxazole ring. (99m)Tc experiments demonstrate efficient radiolabeling with click, then chelate; however, the chelate, then click approach led to faster product formation, but lower yields compared to the Re analogues.

  6. Comparative kinetics of damage to the plasma and mitochondrial membranes by intra-cellularly synthesized and externally-provided photosensitizers using multi-color FACS.

    Science.gov (United States)

    Haupt, Sara; Malik, Zvi; Ehrenberg, Benjamin

    2014-01-01

    Photodynamic therapy (PDT) of cancer involves inflicting lethal damage to the cells of malignant tumors, primarily by singlet oxygen that is generated following light-absorption in a photosensitizer molecule. Dysfunction of cells is manifested in many ways, including peroxidation of cellular components, membrane rupture, depolarization of electric potentials, termination of mitochondrial activity, onset of apoptosis and necrosis and eventually cell lysis. These events do not necessarily occur in linear fashion and different types of damage to cell components occur, most probably, in parallel. In this report we measured the relative rates of damage to two cellular membranes: the plasma membrane and the mitochondrial membrane. We employed photosensitizers of diverse hydrophobicities and used different incubation procedures, which lead to their different intra-cellular localizations. We monitored the damage that was inflicted on these membranes, by employing optical probes of membrane integrity, in a multi-color FACS experiment. The potentiometric indicator JC-1 monitored the electric cross-membrane potential of the mitochondria and the fluorometric indicator Draq7 monitored the rupture of the plasma membrane. We show that the electric depolarization of the mitochondrial membrane and the damage to the enveloping plasma membrane proceed with different kinetics that reflect the molecular character and intracellular location of the sensitizer: PpIX that is synthesized in the cells from ALA causes rapid mitochondrial damage and very slow damage to the plasma membrane, while externally added PpIX has an opposite effect. The hydrophilic sensitizer HypS4 can be taken up by the cells by different incubation conditions, and these affect its intracellular location, and as a consequence either the plasma membrane or the mitochondria is damaged first. A similar correlation was found for additional extracellularly-provided photosensitizers HP and PpIX.

  7. Cu-Free 1,3-Dipolar Cycloaddition Click Reactions To Form Isoxazole Linkers in Chelating Ligands for fac-[MI(CO)3]+ Centers (M = Re, 99mTc)

    OpenAIRE

    Bottorff, Shalina C.; Kasten, Benjamin B.; Stojakovic, Jelena; Moore, Adam L.; MacGillivray, Leonard R.; Benny, Paul D.

    2014-01-01

    Isoxazole ring formation was examined as a potential Cu-free alternative click reaction to CuI-catalyzed alkyne/azide cycloaddition. The isoxazole reaction was explored at macroscopic and radiotracer concentrations with the fac-[MI(CO)3]+ (M = Re, 99mTc) core for use as a noncoordinating linker strategy between covalently linked molecules. Two click assembly methods (click, then chelate and chelate, then click) were examined to determine the feasibility of isoxazole ring formation with either...

  8. mTOR Ser-2481 autophosphorylation monitors mTORC-specific catalytic activity and clarifies rapamycin mechanism of action.

    Science.gov (United States)

    Soliman, Ghada A; Acosta-Jaquez, Hugo A; Dunlop, Elaine A; Ekim, Bilgen; Maj, Nicole E; Tee, Andrew R; Fingar, Diane C

    2010-03-12

    The mammalian target of rapamycin (mTOR) Ser/Thr kinase signals in at least two multiprotein complexes distinguished by their different partners and sensitivities to rapamycin. Acute rapamycin inhibits signaling by mTOR complex 1 (mTORC1) but not mTOR complex 2 (mTORC2), which both promote cell growth, proliferation, and survival. Although mTORC2 regulation remains poorly defined, diverse cellular mitogens activate mTORC1 signaling in a manner that requires sufficient levels of amino acids and cellular energy. Before the identification of distinct mTOR complexes, mTOR was reported to autophosphorylate on Ser-2481 in vivo in a rapamycin- and amino acid-insensitive manner. These results suggested that modulation of mTOR intrinsic catalytic activity does not universally underlie mTOR regulation. Here we re-examine the regulation of mTOR Ser-2481 autophosphorylation (Ser(P)-2481) in vivo by studying mTORC-specific Ser(P)-2481 in mTORC1 and mTORC2, with a primary focus on mTORC1. In contrast to previous work, we find that acute rapamycin and amino acid withdrawal markedly attenuate mTORC1-associated mTOR Ser(P)-2481 in cycling cells. Although insulin stimulates both mTORC1- and mTORC2-associated mTOR Ser(P)-2481 in a phosphatidylinositol 3-kinase-dependent manner, rapamycin acutely inhibits insulin-stimulated mTOR Ser(P)-2481 in mTORC1 but not mTORC2. By interrogating diverse mTORC1 regulatory input, we find that without exception mTORC1-activating signals promote, whereas mTORC1-inhibitory signals decrease mTORC1-associated mTOR Ser(P)-2481. These data suggest that mTORC1- and likely mTORC2-associated mTOR Ser-2481 autophosphorylation directly monitors intrinsic mTORC-specific catalytic activity and reveal that rapamycin inhibits mTORC1 signaling in vivo by reducing mTORC1 catalytic activity.

  9. FUNCTIONS OF THE mTOR SIGNALING PATHWAY IN NORMAL ARTICULAR CARTILAGE CHONDROCYTES AND IN OSTEOARTHRITIS

    Directory of Open Access Journals (Sweden)

    E. V. Chetina

    2016-01-01

    Full Text Available Osteoarthritis  (OA is a chronic disease associated with pain, stiffness, limited mobility and joint inflammation, as well as articular cartilage destruction.  Recent studies have shown the importance  of chondrocyte  differentiation (hypertrophy as one of the mechanisms  of cartilage degradation in OA. This suggests that chondrocyte  metabolism undergoes the profound changes during cartilage resorption,  which are due to dysregulation of cell function. One of the major cellular metabolic regulators is the protein mTOR (mechanistic target of rapamycin that controls cell growth, proliferation, protein biosynthesis and integrates extracellular signals from growth factors and hormones with amino acid availability and intracellular energy status. The importance  of mTOR activity for articular cartilage destruction  in OAis confirmed by significant changes in the work of mTOR regulatory network that involves multiple intracellular (growth factors, adenosine triphosphate, oxygen availability, and autophagy and extracellular (glucose, amino acids, lipids, and hexosamine signals. Moreover, the altered expression of the mTOR gene in the blood of patients with OA is associated with either increased pain or synovitis, which indicates that there is a strong metabolic heterogeneity in patients with OA and a need for a differentiated therapeutic  approach. The above problems are discussed in this review.

  10. The Importance of the mTOR Regulatory Network in Chondrocyte Biology and Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Elena V. Tchetina

    2014-07-01

    Full Text Available Osteoarthritis (OA is a chronic disorder associated mainly with pain, limited range of motion, stiffness, joint inflammation, and articular cartilage (AC destruction. Recent studies demonstrated the involvement of chondrocyte differentiation (hypertrophy as one of the mechanisms of cartilage degradation in OA. This indicates the involvement of profound alterations in chondrocyte metabolism in the course of cartilage resorption orchestrated by principal changes in the regulation of cellular function. Mammalian target of rapamycin (mTOR controls critical cellular processes such as growth, proliferation, and protein synthesis, and integrates extracellular signals from growth factors and hormones with amino acid availability and intracellular energy status. The importance of mTOR activity during AC destruction in OA is supported by considerable alterations in the mTOR regulatory network, involving multiple intracellular (availability of growth factors, adenosine triphosphate [ATP], and oxygen as well as autophagy and extracellular (glucose, amino acid, lipid, and hexosamine signals. Moreover, variable mTOR gene expression in the peripheral blood of OA patients is associated with increases in pain or synovitis, and indicates a profound metabolic dissimilarity among patients that might require differential approaches to treatment. These issues are discussed in the present review article.

  11. Formal Test Automation: The Conference protocol with TGV/TorX

    NARCIS (Netherlands)

    Ural, Hasan; Du Bousquet, Lydie; Ramangalahy, Solofo; Probert, Robert L.; von Bochmann, Gregor; Simon, Severine; Viho, Cesar; Belinfante, Axel; de Vries, R.G.

    We present an experiment of automated formal conformance testing of the Conference Protocol Entity as reported in [2]. Our approach differs from other experiments, since it investigates the combination of the tools TGV for abstract test generation and TorX for test execution.

  12. Enoyl-CoA hydratase-1 regulates mTOR signaling and apoptosis by sensing nutrients.

    Science.gov (United States)

    Zhang, Ya-Kun; Qu, Yuan-Yuan; Lin, Yan; Wu, Xiao-Hui; Chen, Hou-Zao; Wang, Xu; Zhou, Kai-Qiang; Wei, Yun; Guo, Fushen; Yao, Cui-Fang; He, Xia-Di; Liu, Li-Xia; Yang, Chen; Guan, Zong-Yuan; Wang, Shi-Dong; Zhao, Jianyuan; Liu, De-Pei; Zhao, Shi-Min; Xu, Wei

    2017-09-06

    The oncogenic mechanisms of overnutrition, a confirmed independent cancer risk factor, remain poorly understood. Herein, we report that enoyl-CoA hydratase-1 (ECHS1), the enzyme involved in the oxidation of fatty acids (FAs) and branched-chain amino acids (BCAAs), senses nutrients and promotes mTOR activation and apoptotic resistance. Nutrients-promoted acetylation of lys(101) of ECHS1 impedes ECHS1 activity by impairing enoyl-CoA binding, promoting ECHS1 degradation and blocking its mitochondrial translocation through inducing ubiquitination. As a result, nutrients induce the accumulation of BCAAs and FAs that activate mTOR signaling and stimulate apoptosis, respectively. The latter was overcome by selection of BCL-2 overexpressing cells under overnutrition conditions. The oncogenic effects of nutrients were reversed by SIRT3, which deacetylates lys(101) acetylation. Severely decreased ECHS1, accumulation of BCAAs and FAs, activation of mTOR and overexpression of BCL-2 were observed in cancer tissues from metabolic organs. Our results identified ECHS1, a nutrients-sensing protein that transforms nutrient signals into oncogenic signals.Overnutrition has been linked to increased risk of cancer. Here, the authors show that exceeding nutrients suppress Enoyl-CoA hydratase-1 (ECHS1) activity by inducing its acetylation resulting in accumulation of fatty acids and branched-chain amino acids and oncogenic mTOR activation.

  13. Targeting mTOR with rapamycin: One dose does not fit all

    Science.gov (United States)

    Foster, David A.; Toschi, Alfredo

    2009-01-01

    A puzzling aspect of rapamycin-based therapeutic strategies is the wide disparity in the doses needed to suppress mTOR under different circumstances. A recent study revealing mechanistically how rapamycin suppresses mTOR provides two explanations for the differential sensitivities to rapamycin. First, mTOR exists as two functionally distinct complexes (mTORC1 and mTORC2), and while rapamycin suppresses both, it does so at very different concentrations. Whereas mTORC1 is suppressed by concentrations of rapamycin in the low nM range, mTORC2 generally requires low μM concentrations. Second, the efficacy of rapamycin is dependent on the level of phosphatidic acid (PA), which is required for the assembly of both mTORC1 and mTORC2 complexes. Rapamycin interacts with mTOR in a manner that is competitive with PA. Therefore, elevated levels of PA, which is common in cancer cells, increases the level of rapamycin needed to suppress both mTORC1 and mTORC2. A practical outcome of the recent study is that if PA levels are suppressed, mTORC2 becomes sensitive to concentrations of rapamycin that can be achieved clinically. Since mTORC2 is likely more critical for survival signals in cancer cells, the recent findings suggest new strategies for enhancing the efficacy of rapamycin-based therapeutic approaches in cancer cells. PMID:19270529

  14. TOR regulates cell death induced by telomere dysfunction in budding yeast.

    Directory of Open Access Journals (Sweden)

    Haiyan Qi

    Full Text Available Telomere dysfunction is known to induce growth arrest (senescence and cell death. However, the regulation of the senescence-death process is poorly understood. Here using a yeast dysfunctional telomere model cdc13-1, which carries a temperature sensitive-mutant telomere binding protein Cdc13p, we demonstrate that inhibition of TOR (Target of Rapamycin, a central regulator of nutrient pathways for cell growth, prevents cell death, but not growth arrest, induced by inactivation of Cdc13-1p. This function of TOR is novel and separable from its G1 inhibition function, and not associated with alterations in the telomere length, the amount of G-tails, and the telomere position effect (TPE in cdc13-1 cells. Furthermore, antioxidants were also shown to prevent cell death initiated by inactivation of cdc13-1. Moreover, inhibition of TOR was also shown to prevent cell death induced by inactivation of telomerase in an est1 mutant. Interestingly, rapamycin did not prevent cell death induced by DNA damaging agents such as etoposide and UV. In the aggregate, our results suggest that the TOR signaling pathway is specifically involved in the regulation of cell death initiated by telomere dysfunction.

  15. A Review of mTOR Pathway Inhibitors in Gynecologic Cancer

    Directory of Open Access Journals (Sweden)

    Andréia Cristina de Melo

    2017-01-01

    Full Text Available The treatment of advanced gynecologic cancers remains palliative in most of cases. Although systemic treatment has entered into the era of targeted drugs the antitumor efficacies of current therapies are still limited. In this context there is a great need for more active treatment and rationally designed targeted therapies. The PI3K/AKT/mTOR is a signaling pathway in mammal cells that coordinates important cell activities. It has a critical function in the survival, growth, and proliferation of malignant cells and was object of important research in the last two decades. The mTOR pathway emerges as an attractive therapeutic target in cancer because it serves as a convergence point for many growth stimuli and, through its downstream substrates, controls cellular processes that contribute to the initiation and maintenance of cancer. Aberrant PI3K-dependent signaling occurs frequently in a wide range of tumor types, including endometrial, cervical, and ovarian cancers. The present study reviewed the available evidence regarding the potential impact of some mTOR pathway inhibitors in the treatment of gynecological cancer. Few advances in medical management have occurred in recent years in the treatment of advanced or recurrent gynecological malignancies, and a poor prognosis remains. Rationally designed molecularly targeted therapy is an emerging and important option in this setting; then more investigation in PI3K/AKT/mTOR pathway-targeted therapies is warranted.

  16. Trichomonas vaginalis metalloproteinase induces mTOR cleavage of SiHa cells.

    Science.gov (United States)

    Quan, Juan-Hua; Choi, In-Wook; Yang, Jung-Bo; Zhou, Wei; Cha, Guang-Ho; Zhou, Yu; Ryu, Jae-Sook; Lee, Young-Ha

    2014-12-01

    Trichomonas vaginalis secretes a number of proteases which are suspected to be the cause of pathogenesis; however, little is understood how they manipulate host cells. The mammalian target of rapamycin (mTOR) regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, and transcription. We detected various types of metalloproteinases including GP63 protein from T. vaginalis trophozoites, and T. vaginalis GP63 metalloproteinase was confirmed by sequencing and western blot. When SiHa cells were stimulated with live T. vaginalis, T. vaginalis excretory-secretory products (ESP) or T. vaginalis lysate, live T. vaginalis and T. vaginalis ESP induced the mTOR cleavage in both time- and parasite load-dependent manner, but T. vaginalis lysate did not. Pretreatment of T. vaginalis with a metalloproteinase inhibitor, 1,10-phenanthroline, completely disappeared the mTOR cleavage in SiHa cells. Collectively, T. vaginalis metallopeptidase induces host cell mTOR cleavage, which may be related to survival of the parasite.

  17. I GIS nell’analisi dello sviluppo urbano rizomatico di Tor Vergata

    Directory of Open Access Journals (Sweden)

    Luisa Carbone

    2013-06-01

    Full Text Available L’intento dell’articolo è quello di osservare la complessità dei rapporti che legano il Campus universitario di Roma “Tor Vergata” all’universo discorsivo che lo riguarda, dalle ex borgate abusive alle immagini di periferie riqualificate del Municipio VIII, elevate nel Nuovo Piano Regolatore di Roma al rango di Centralità. Per comprendere la dimensione di relazione del sistema Tor Vergata è fondamentale ricorrere all’applicazione del metodo rizomatico e virtuale della performative mapping. Un processo che implica l’attribuzione di un nuovo senso e un diverso ordine a ciò che è preesistente. In questo contesto solo la potenzialità del GIS può orientare nel de-codificare la configurazione territoriale di Tor Vergata che vede nel rizoma, nella molteplicità dei punti di vista e nella differenza, il principio fondamentale del suo agire. La lettura rizomatica del GIS, infatti, conferisce un’immagine innovativa sostituendo all’idea di precarietà, l’idea di un tessuto non privo di forma, che connota Tor Vergata come “luogo”, non più come periferia.

  18. PRAS40 is an integral regulatory component of erythropoietin mTOR signaling and cytoprotection.

    Directory of Open Access Journals (Sweden)

    Zhao Zhong Chong

    Full Text Available Emerging strategies that center upon the mammalian target of rapamycin (mTOR signaling for neurodegenerative disorders may bring effective treatment for a number of difficult disease entities. Here we show that erythropoietin (EPO, a novel agent for nervous system disorders, prevents apoptotic SH-SY5Y cell injury in an oxidative stress model of oxygen-glucose deprivation through phosphatidylinositol-3-kinase (PI 3-K/protein kinase B (Akt dependent activation of mTOR signaling and phosphorylation of the downstream pathways of p70 ribosomal S6 kinase (p70S6K, eukaryotic initiation factor 4E-binding protein 1 (4EBP1, and proline rich Akt substrate 40 kDa (PRAS40. PRAS40 is an important regulatory component either alone or in conjunction with EPO signal transduction that can determine cell survival through apoptotic caspase 3 activation. EPO and the PI 3-K/Akt pathways control cell survival and mTOR activity through the inhibitory post-translational phosphorylation of PRAS40 that leads to subcellular binding of PRAS40 to the cytoplasmic docking protein 14-3-3. However, modulation and phosphorylation of PRAS40 is independent of other protective pathways of EPO that involve extracellular signal related kinase (ERK 1/2 and signal transducer and activator of transcription (STAT5. Our studies highlight EPO and PRAS40 signaling in the mTOR pathway as potential therapeutic strategies for development against degenerative disorders that lead to cell demise.

  19. Cross-talk between AMPK and mTOR in regulating energy balance.

    Science.gov (United States)

    Xu, Jia; Ji, Jian; Yan, Xiang-Hua

    2012-01-01

    Energy balance is maintained by a complex homeostatic system involving some signaling pathways and "nutrient sensors" in multiple tissues and organs. Any defect associated with the pathways can lead to metabolic disorders including obesity, type 2 diabetes, and the metabolic syndrome. The 5'-adenosine monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) appear to play a significant role in the intermediary metabolism of these diseases. AMPK is involved in the fundamental regulation of energy balance at the whole body level by responding to hormonal and nutrient signals in the central nervous system and peripheral tissues that modulate food intake and energy expenditure. Mammalian target of rapamycin (mTOR),is one of the downstream targets of AMPK functions as an intracellular nutrient sensor to control protein synthesis, cell growth, and metabolism. Recent research demonstrated the possible interplay between mTOR and AMPK signaling pathways. In this review, we will present current knowledge of AMPK and mTOR pathways in regulating energy balance and demonstrate the convergence between these two pathways.

  20. mTOR Kinase: A Possible Pharmacological Target in the Management of Chronic Pain

    Directory of Open Access Journals (Sweden)

    Lucia Lisi

    2015-01-01

    Full Text Available Chronic pain represents a major public health problem worldwide. Current pharmacological treatments for chronic pain syndromes, including neuropathic pain, are only partially effective, with significant pain relief achieved in 40–60% of patients. Recent studies suggest that the mammalian target of rapamycin (mTOR kinase and downstream effectors may be implicated in the development of chronic inflammatory, neuropathic, and cancer pain. The expression and activity of mTOR have been detected in peripheral and central regions involved in pain transmission. mTOR immunoreactivity was found in primary sensory axons, in dorsal root ganglia (DRG, and in dorsal horn neurons. This kinase is a master regulator of protein synthesis, and it is critically involved in the regulation of several neuronal functions, including the synaptic plasticity that is a major mechanism leading to the development of chronic pain. Enhanced activation of this pathway is present in different experimental models of chronic pain. Consistently, pharmacological inhibition of the kinase activity turned out to have significant antinociceptive effects in several experimental models of inflammatory and neuropathic pain. We will review the main evidence from animal and human studies supporting the hypothesis that mTOR may be a novel pharmacological target for the management of chronic pain.

  1. LIF promotes tumorigenesis and metastasis of breast cancer through the AKT-mTOR pathway

    Science.gov (United States)

    Yu, Haiyang; Wu, Lihua; Zhao, Yuhan; Zhang, Cen; Yue, Xuetian; Liu, Zhen; Wu, Hao; Haffty, Bruce G.; Feng, Zhaohui; Hu, Wenwei

    2014-01-01

    Leukemia inhibitory factor (LIF) is a multi-functional cytokine protein. The role of LIF in tumorigenesis is not well-understood. Here, we found that LIF promotes tumorigenesis and metastasis of breast cancer. LIF promotes cell proliferation and anchorage-independent growth of breast cancer cells in vitro, and the growth of xenograft breast tumors in vivo. LIF also promotes invasion and migration of breast cancer cells in vitro and metastasis of breast cancer in vivo. We found that LIF activates the AKT-mTOR signaling pathway to promote tumorigenesis and metastasis of breast cancer. Inhibiting the AKT activity can largely block the activation of the mTOR pathway by LIF, suggesting that LIF activates the mTOR pathway through AKT. Inhibiting the AKT activity as well as inhibiting the mTOR activity largely block the promoting effect of LIF on tumorigenesis and metastasis. Furthermore, overexpression of LIF is significantly associated with a poorer relapse free survival in breast cancer patients. Taken together, our data strongly suggest that LIF plays an important role in the tumorigenesis and metastasis of breast cancer, and could be an important prognostic marker for breast cancer. PMID:24553191

  2. Molecular phylogenetic analysis of Vibrio cholerae O1 El Tor strains ...

    Indian Academy of Sciences (India)

    Unknown

    all five ISR classes, could be successfully used to study phylogeny in this organism. [Ghatak A, Majumdar A and Ghosh R K 2005 Molecular phylogenetic analysis of Vibrio cholerae O1 El Tor strains isolated before, during and after the O139 outbreak based on the intergenomic heterogeneity of the 16S-23S rRNA intergenic ...

  3. The mTOR inhibitor sirolimus suppresses renal, hepatic, and cardiac tissue cellular respiration.

    Science.gov (United States)

    Albawardi, Alia; Almarzooqi, Saeeda; Saraswathiamma, Dhanya; Abdul-Kader, Hidaya Mohammed; Souid, Abdul-Kader; Alfazari, Ali S

    2015-01-01

    The purpose of this in vitro study was to develop a useful biomarker (e.g., cellular respiration, or mitochondrial O2 consumption) for measuring activities of mTOR inhibitors. It measured the effects of commonly used immunosuppressants (sirolimus-rapamycin, tacrolimus, and cyclosporine) on cellular respiration in target tissues (kidney, liver, and heart) from C57BL/6 mice. The mammalian target of rapamycin (mTOR), a serine/ threonine kinase that supports nutrient-dependent cell growth and survival, is known to control energy conversion processes within the mitochondria. Consistently, inhibitors of mTOR (e.g., rapamycin, also known as sirolimus or Rapamune®) have been shown to impair mitochondrial function. Inhibitors of the calcium-dependent serine/threonine phosphatase calcineurin (e.g., tacrolimus and cyclosporine), on the other hand, strictly prevent lymphokine production leading to a reduced T-cell function. Sirolimus (10 μM) inhibited renal (22%, P=0.002), hepatic (39%, Pcellular respiration. Tacrolimus and cyclosporine had no or minimum effects on cellular respiration in these tissues. Thus, these results clearly demonstrate that impaired cellular respiration (bioenergetics) is a sensitive biomarker of the immunosuppressants that target mTOR.

  4. The Role of mTOR Inhibitors in Liver Transplantation: Reviewing the Evidence

    Science.gov (United States)

    Klintmalm, Goran B.; Nashan, Björn

    2014-01-01

    Despite the success of liver transplantation, long-term complications remain, including de novo malignancies, metabolic syndrome, and the recurrence of hepatitis C virus (HCV) and hepatocellular carcinoma (HCC). The current mainstay of treatment, calcineurin inhibitors (CNIs), can also worsen posttransplant renal dysfunction, neurotoxicity, and diabetes. Clearly there is a need for better immunosuppressive agents that maintain similar rates of efficacy and renal function whilst minimizing adverse effects. The mammalian target of rapamycin (mTOR) inhibitors with a mechanism of action that is different from other immunosuppressive agents has the potential to address some of these issues. In this review we surveyed the literature for reports of the use of mTOR inhibitors in adult liver transplantation with respect to renal function, efficacy, safety, neurological symptoms, de novo tumors, and the recurrence of HCC and HCV. The results of our review indicate that mTOR inhibitors are associated with efficacy comparable to CNIs while having benefits on renal function in liver transplantation. We also consider newer dosing schedules that may limit side effects. Finally, we discuss evidence that mTOR inhibitors may have benefits in the oncology setting and in relation to HCV-related allograft fibrosis, metabolic syndrome, and neurotoxicity. PMID:24719752

  5. A systems study reveals concurrent activation of AMPK and mTOR by amino acids

    NARCIS (Netherlands)

    Pezze, Piero Dalle; Ruf, Stefanie; Sonntag, Annika G; Langelaar-Makkinje, Miriam; Hall, Philip; Heberle, Alexander M; Navas, Patricia Razquin; van Eunen, Karen; Tölle, Regine C; Schwarz, Jennifer J; Wiese, Heike; Warscheid, Bettina; Deitersen, Jana; Stork, Björn; Fäßler, Erik; Schäuble, Sascha; Hahn, Udo; Horvatovich, Peter; Shanley, Daryl P; Thedieck, Kathrin

    2016-01-01

    Amino acids (aa) are not only building blocks for proteins, but also signalling molecules, with the mammalian target of rapamycin complex 1 (mTORC1) acting as a key mediator. However, little is known about whether aa, independently of mTORC1, activate other kinases of the mTOR signalling network. To

  6. IL-7 Restores T Lymphocyte Immunometabolic Failure in Septic Shock Patients through mTOR Activation.

    Science.gov (United States)

    Venet, Fabienne; Demaret, Julie; Blaise, Benjamin J; Rouget, Christelle; Girardot, Thibaut; Idealisoa, Estellie; Rimmelé, Thomas; Mallet, François; Lepape, Alain; Textoris, Julien; Monneret, Guillaume

    2017-09-01

    T lymphocyte alterations are central to sepsis pathophysiology, whereas related mechanisms remain poorly understood. We hypothesized that metabolic alterations could play a role in sepsis-induced T lymphocyte dysfunction. Samples from septic shock patients were obtained at day 3 and compared with those from healthy donors. T cell metabolic status was evaluated in the basal condition and after T cell stimulation. We observed that basal metabolic content measured in lymphocytes by nuclear magnetic resonance spectroscopy was altered in septic patients. Basal ATP concentration, oxidative phosphorylation (OXPHOS), and glycolysis pathways in T cells were decreased as well. After stimulation, T lymphocytes from patients failed to induce glycolysis, OXPHOS, ATP production, GLUT1 expression, glucose entry, and proliferation to similar levels as controls. This was associated with significantly altered mTOR, but not Akt or HIF-1α, activation and only minor AMPKα phosphorylation dysfunction. IL-7 treatment improved mTOR activation, GLUT1 expression, and glucose entry in septic patients' T lymphocytes, leading to their enhanced proliferation. mTOR activation was central to this process, because rapamycin systematically inhibited the beneficial effect of recombinant human IL-7. We demonstrate the central role of immunometabolism and, in particular, mTOR alterations in the pathophysiology of sepsis-induced T cell alterations. Our results support the rationale for targeting metabolism in sepsis with recombinant human IL-7 as a treatment option. Copyright © 2017 by The American Association of Immunologists, Inc.

  7. The yeast Tor signaling pathway is involved in G2/M transition via polo-kinase.

    Directory of Open Access Journals (Sweden)

    Akio Nakashima

    Full Text Available The target of rapamycin (Tor protein plays central roles in cell growth. Rapamycin inhibits cell growth and promotes cell cycle arrest at G1 (G0. However, little is known about whether Tor is involved in other stages of the cell division cycle. Here we report that the rapamycin-sensitive Tor complex 1 (TORC1 is involved in G2/M transition in S. cerevisiae. Strains carrying a temperature-sensitive allele of KOG1 (kog1-105 encoding an essential component of TORC1, as well as yeast cell treated with rapamycin show mitotic delay with prolonged G2. Overexpression of Cdc5, the yeast polo-like kinase, rescues the growth defect of kog1-105, and in turn, Cdc5 activity is attenuated in kog1-105 cells. The TORC1-Type2A phosphatase pathway mediates nucleocytoplasmic transport of Cdc5, which is prerequisite for its proper localization and function. The C-terminal polo-box domain of Cdc5 has an inhibitory role in nuclear translocation. Taken together, our results indicate a novel function of Tor in the regulation of cell cycle and proliferation.

  8. Figure 1. T. tor species. Figure 2. Long PCR products of ...

    Indian Academy of Sciences (India)

    Annam

    Figure 2. Long PCR products of mitochondrial DNA from the fish T. tor. Lane 1, amplified product using L-12321-Leu and S-LA-16S-H primers. Lane 2, amplified product using H-12321 –Leu and S-LA-16S-L primers. Lane M, 1-Kb DNA ladder. 8 kb ...

  9. The effects of β-elemene on the expression of mTOR, HIF-1α ...

    African Journals Online (AJOL)

    The purpose of this manuscript was to study the regulation effects of â-elemene combined with radiotherapy on three different gene expressions in lung adenocarcinoma A549 cell. mTOR gene, HIF-1á gene, Survivin gene were included in the gene group. Cell culture and RT-PCR were applied to finish this research.

  10. Carboxy terminal tail of polycystin-1 regulates localization of TSC2 to repress mTOR.

    Directory of Open Access Journals (Sweden)

    Ruhee Dere

    2010-02-01

    Full Text Available Autosomal dominant polycystic kidney disease (ADPKD is a commonly inherited renal disorder caused by defects in the PKD1 or PKD2 genes. ADPKD is associated with significant morbidity, and is a major underlying cause of end-stage renal failure (ESRF. Commonly, treatment options are limited to the management of hypertension, cardiovascular risk factors, dialysis, and transplantation when ESRF develops, although several new pharmacotherapies, including rapamycin, have shown early promise in animal and human studies. Evidence implicates polycystin-1 (PC-1, the gene product of the PKD1 gene, in regulation of the mTOR pathway. Here we demonstrate a mechanism by which the intracellular, carboxy-terminal tail of polycystin-1 (CP1 regulates mTOR signaling by altering the subcellular localization of the tuberous sclerosis complex 2 (TSC2 tumor suppressor, a gatekeeper for mTOR activity. Phosphorylation of TSC2 at S939 by AKT causes partitioning of TSC2 away from the membrane, its GAP target Rheb, and its activating partner TSC1 to the cytosol via 14-3-3 protein binding. We found that TSC2 and a C-terminal polycystin-1 peptide (CP1 directly interact and that a membrane-tethered CP1 protects TSC2 from AKT phosphorylation at S939, retaining TSC2 at the membrane to inhibit the mTOR pathway. CP1 decreased binding of 14-3-3 proteins to TSC2 and increased the interaction between TSC2 and its activating partner TSC1. Interestingly, while membrane tethering of CP1 was required to activate TSC2 and repress mTOR, the ability of CP1 to inhibit mTOR signaling did not require primary cilia and was independent of AMPK activation. These data identify a unique mechanism for modulation of TSC2 repression of mTOR signaling via membrane retention of this tumor suppressor, and identify PC-1 as a regulator of this downstream component of the PI3K signaling cascade.

  11. Graphene susceptibility in Holstein model

    Energy Technology Data Exchange (ETDEWEB)

    Mousavi, Hamze, E-mail: hamze.mousavi@gmail.co [Department of Physics, Razi University, Kermanshah (Iran, Islamic Republic of); Nano Science and Nano Technology Research Center, Razi University, Kermanshah (Iran, Islamic Republic of)

    2011-06-15

    We study the effects of the electron-phonon interaction on the temperature dependence of the orbital magnetic susceptibility of monolayer graphene. We use the linear response theory and Green's function formalism within the Holstein Hamiltonian model. The results show that the effects of the electron-phonon interaction on the susceptibility of graphene sheet have different behaviors in two temperature regions. In the low temperature region, susceptibility increases when the electron-phonon coupling strength increases. On the other hand, the susceptibility reduces with increasing the electron-phonon coupling strength in the high temperature region. - Highlights: Effect of electron-phonon interaction on the susceptibility of graphene is studied. Linear response theory and Green's function technique in Holstein model are used. Effect of electron-phonon on susceptibility has different behaviors in two temperature regions.

  12. Topological susceptibility from slabs

    Energy Technology Data Exchange (ETDEWEB)

    Bietenholz, Wolfgang [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, Distrito Federal, C.P. 04510 (Mexico); Forcrand, Philippe de [Institute for Theoretical Physics, ETH Zürich,CH-8093 Zürich (Switzerland); CERN, Physics Department, TH Unit, CH-1211 Geneva 23 (Switzerland); Gerber, Urs [Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, A.P. 70-543, Distrito Federal, C.P. 04510 (Mexico); Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo,Edificio C-3, Apdo. Postal 2-82, Morelia, Michoacán, C.P. 58040 (Mexico)

    2015-12-14

    In quantum field theories with topological sectors, a non-perturbative quantity of interest is the topological susceptibility χ{sub t}. In principle it seems straightforward to measure χ{sub t} by means of Monte Carlo simulations. However, for local update algorithms and fine lattice spacings, this tends to be difficult, since the Monte Carlo history rarely changes the topological sector. Here we test a method to measure χ{sub t} even if data from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as slabs. Assuming a Gaussian distribution of these charges, this method enables the evaluation of χ{sub t}, as we demonstrate with numerical results for non-linear σ-models.

  13. Topological Susceptibility from Slabs

    CERN Document Server

    Bietenholz, Wolfgang; Gerber, Urs

    2015-01-01

    In quantum field theories with topological sectors, a non-perturbative quantity of interest is the topological susceptibility chi_t. In principle it seems straightforward to measure chi_t by means of Monte Carlo simulations. However, for local update algorithms and fine lattice spacings, this tends to be difficult, since the Monte Carlo history rarely changes the topological sector. Here we test a method to measure chi_t even if data from only one sector are available. It is based on the topological charges in sub-volumes, which we denote as slabs. Assuming a Gaussian distribution of these charges, this method enables the evaluation of chi_t, as we demonstrate with numerical results for non-linear sigma-models.

  14. Defending Tor from Network Adversaries: A Case Study of Network Path Prediction

    Directory of Open Access Journals (Sweden)

    Juen Joshua

    2015-06-01

    Full Text Available The Tor anonymity network has been shown vulnerable to traffic analysis attacks by autonomous systems (ASes and Internet exchanges (IXes, which can observe different overlay hops belonging to the same circuit. We evaluate whether network path prediction techniques provide an accurate picture of the threat from such adversaries, and whether they can be used to avoid this threat. We perform a measurement study by collecting 17.2 million traceroutes from Tor relays to destinations around the Internet. We compare the collected traceroute paths to predicted paths using state-of-the-art path inference techniques. We find that traceroutes present a very different picture, with the set of ASes seen in the traceroute path differing from the predicted path 80% of the time. We also consider the impact that prediction errors have on Tor security. Using a simulator to choose paths over a week, our traceroutes indicate a user has nearly a 100% chance of at least one compromise in a week with 11% of total paths containing an AS compromise and less than 1% containing an IX compromise when using default Tor selection. We find modifying the path selection to choose paths predicted to be safe lowers total paths with an AS compromise to 0.14% but still presents a 5–11% chance of at least one compromise in a week while making 5% of paths fail, with 96% of failures due to false positives in path inferences. Our results demonstrate more measurement and better path prediction is necessary to mitigate the risk of AS and IX adversaries to Tor.

  15. GLP-1 analogue improves hepatic lipid accumulation by inducing autophagy via AMPK/mTOR pathway

    Energy Technology Data Exchange (ETDEWEB)

    He, Qin; Sha, Sha; Sun, Lei; Zhang, Jing; Dong, Ming, E-mail: dr_dongming@126.com

    2016-08-05

    The incidence of nonalcoholic fatty liver disease (NAFLD) keeps rising year by year, and NAFLD is rapidly becoming the most common liver disease worldwide. Clinical studies have found that glucagon-like peptide-1 (GLP-1) analogue, liraglutide (LRG), cannot only reduce glucose levels, but also improve hepatic lipase, especially in patients also with type 2 diabetes mellitus (T2DM). In addition, enhancing autophagy decreases lipid accumulation in hepatocytes. The aim of the present study is to explore the effect of LRG on hepatocyte steatosis and the possible role of autophagy. We set up an obesity mouse model with a high-fat diet (HFD) and induced hepatocyte steatosis with free fatty acids (FFA) in human L-O2 cells. LRG and two inhibitors of autophagy, Chloroquine (CQ) and bafilomycin A1 (Baf), were added into each group, respectively. The lipid profiles and morphological modifications of each group were tested. Immunohistochemistry, immunofluorescence staining and transmission electron microscopy (TEM) were used to measure autophagy in this study. The autophagy protein expression of SQSTM1 (P62), and LC3B, along with the signaling pathway proteins of mTOR, phosphorylated mTOR (p-mTOR), AMPK, phosphorylated AMPK (p-AMPK) and Beclin1, were evaluated by western blot. Our results showed that LRG improved hepatocyte steatosis by inducing autophagy, and the AMPK/mTOR pathway is involved. These findings suggest an important mechanism for the positive effects of LRG on hepatic steatosis, and provide new evidence for clinical use of LRG in NAFLD. -- Highlights: •Liraglutide reduces lipid accumulation in hepatic steatosis both in vivo and in vitro. •Autophagy was involved in relieving effects of liraglutide on hepatic steatosis. •AMPK/mTOR pathway was involved in liraglutide-induced autophagy.

  16. Dissociation of the Pharmacological Effects of THC by mTOR Blockade

    Science.gov (United States)

    Puighermanal, Emma; Busquets-Garcia, Arnau; Gomis-González, Maria; Marsicano, Giovanni; Maldonado, Rafael; Ozaita, Andrés

    2013-01-01

    The potential therapeutic benefits of cannabinoid compounds have raised interest in understanding the molecular mechanisms that underlie cannabinoid-mediated effects. We previously showed that the acute amnesic-like effects of delta9-tetrahydrocannabinol (THC) were prevented by the subchronic inhibition of the mammalian target of rapamycin (mTOR) pathway. In the present study, we assess the relevance of the mTOR pathway in other acute and chronic pharmacological effects of THC. The rapamycin derivative temsirolimus, an inhibitor of the mTOR pathway approved by the Food and Drug Administration, prevents both the anxiogenic- and the amnesic-like effects produced by acute THC. In contrast, THC-induced anxiolysis, hypothermia, hypolocomotion, and antinociception are not sensitive to the mTOR inhibition. In addition, a clear tolerance to THC-induced anxiolysis, hypothermia, hypolocomotion, and antinociception was observed after chronic treatment, but not to its anxiogenic- and amnesic-like effects. Temsirolimus pre-treatment prevented the amnesic-like effects of chronic THC without affecting the downregulation of CB1 receptors (CB1R) induced by this chronic treatment. Instead, temsirolimus blockade after chronic THC cessation did not prevent the residual cognitive deficit produced by chronic THC. Using conditional knockout mice lacking CB1R in GABAergic or glutamatergic neurons, we found that GABAergic CB1Rs are mainly downregulated under chronic THC treatment conditions, and CB1–GABA–KO mice did not develop cognitive deficits after chronic THC exposure. Therefore, mTOR inhibition by temsirolimus allows the segregation of the potentially beneficial effects of cannabinoid agonists, such as the anxiolytic and antinociceptive effects, from the negative effects, such as anxiogenic- and amnesic-like responses. Altogether, these results provide new insights for targeting the endocannabinoid system in order to prevent possible side effects. PMID:23358238

  17. Qiliqiangxin Protects Against Cardiac Ischemia-Reperfusion Injury via Activation of the mTOR Pathway

    Directory of Open Access Journals (Sweden)

    Yonglan Zhou

    2015-08-01

    Full Text Available Background/Aims: Qiliqiangxin (QL has been used for the treatment of chronic heart failure in China. Accumulating evidence suggests QL's cardio-protective effects on continuous myocardial ischemia. However, it is unclear whether QL has beneficial effects on cardiac ischemia-reperfusion (I/R injury. Methods: A mouse model of cardiac I/R was established by ligation of the left anterior descending coronary artery for 45 minutes followed by reperfusion. The mice were treated with QL for three days before surgery and continually after I/R. Triphenyltetrazolium chloride staining, echocardiography and Masson's trichrome staining were used to determine infarct size, cardiac function, and fibrosis, respectively. Expression levels of phospho-mTOR (Ser2448, mTOR, phospho-4EBP (Ser65, 4EBP, phospho-Akt (Ser473 and Akt were detected by Western blotting. Results: At 1 day after I/R, QL treatment significantly reduced the infarct size of mice exposed to I/R. At 7 days after I/R, mortality was reduced in QL treated animals in comparison with the control group. In addition, QL treated mice showed increased left ventricular ejection fraction (LVEF and left ventricular fractional shortening (LVFS at 1 and 7 days after I/R. In agreement, Masson's trichrome staining demonstrated that interstitial fibrosis was less pronounced in QL treated mice compared with controls, suggesting that adverse left ventricular remodeling is attenuated in QL treated mice. Moreover, western blotting analysis demonstrated that QL activated the mTOR pathway, while mTOR inhibition via Rapamycin abolished the protective effects of QL against I/R injury. Conclusion: This study suggests that QL attenuates the progression of cardiac remodeling after I/R likely via mTOR activation. This represents a new application for QL in the prevention of I/R injury.

  18. Stoichiometry and assembly of mTOR complexes revealed by single-molecule pulldown.

    Science.gov (United States)

    Jain, Ankur; Arauz, Edwin; Aggarwal, Vasudha; Ikon, Nikita; Chen, Jie; Ha, Taekjip

    2014-12-16

    The mammalian target of rapamycin (mTOR) kinase is a master regulator of cellular, developmental, and metabolic processes. Deregulation of mTOR signaling is implicated in numerous human diseases including cancer and diabetes. mTOR functions as part of either of the two multisubunit complexes, mTORC1 and mTORC2, but molecular details about the assembly and oligomerization of mTORCs are currently lacking. We use the single-molecule pulldown (SiMPull) assay that combines principles of conventional pulldown assays with single-molecule fluorescence microscopy to investigate the stoichiometry and assembly of mTORCs. After validating our approach with mTORC1, confirming a dimeric assembly as previously reported, we show that all major components of mTORC2 exist in two copies per complex, indicating that mTORC2 assembles as a homodimer. Interestingly, each mTORC component, when free from the complexes, is present as a monomer and no single subunit serves as the dimerizing component. Instead, our data suggest that dimerization of mTORCs is the result of multiple subunits forming a composite surface. SiMPull also allowed us to distinguish complex disassembly from stoichiometry changes. Physiological conditions that abrogate mTOR signaling such as nutrient deprivation or energy stress did not alter the stoichiometry of mTORCs. On the other hand, rapamycin treatment leads to transient appearance of monomeric mTORC1 before complete disruption of the mTOR-raptor interaction, whereas mTORC2 stoichiometry is unaffected. These insights into assembly of mTORCs may guide future mechanistic studies and exploration of therapeutic potential.

  19. Fluoxetine regulates mTOR signalling in a region-dependent manner in depression-like mice.

    Science.gov (United States)

    Liu, Xiao-Long; Luo, Liu; Mu, Rong-Hao; Liu, Bin-Bin; Geng, Di; Liu, Qing; Yi, Li-Tao

    2015-11-02

    Previous studies have demonstrated that the mammalian target of rapamycin (mTOR) signaling pathway has an important role in ketamine-induced, rapid antidepressant effects despite the acute administration of fluoxetine not affecting mTOR phosphorylation in the brain. However, the effects of long-term fluoxetine treatment on mTOR modulation have not been assessed to date. In the present study, we examined whether fluoxetine, a type of commonly used antidepressant agent, alters mTOR signaling following chronic administration in different brain regions, including the frontal cortex, hippocampus, amygdala and hypothalamus. We also investigated whether fluoxetine enhanced synaptic protein levels in these regions via the activation of the mTOR signaling pathway and its downstream regulators, p70S6K and 4E-BP-1. The results indicated that chronic fluoxetine treatment attenuated the chronic, unpredictable, mild stress (CUMS)-induced mTOR phosphorylation reduction in the hippocampus and amygdala of mice but not in the frontal cortex or the hypothalamus. Moreover, the CUMS-decreased PSD-95 and synapsin I levels were reversed by fluoxetine, and these effects were blocked by rapamycin only in the hippocampus. In conclusion, our findings suggest that chronic treatment with fluoxetine can induce synaptic protein expression by activating the mTOR signaling pathway in a region-dependent manner and mainly in the hippocampus.

  20. Cord Blood Cells Responses to IL2, IL7 and IL15 Cytokines for mTOR Expression

    Directory of Open Access Journals (Sweden)

    Anahita Mohammadian

    2017-04-01

    Full Text Available Purpose: Mammalian target of rapamycin (mTORis important in hematopoiesis and affect cell growth,differentiation and survival. Although previous studies were identified the effect of cytokines on the mononuclear cells development however the cytokines effect on mTOR in cord blood mononuclear cells was unclear. The aim of this study was to evaluate mTOR expression in cord blood mononuclear and cord blood stem cells (CD34+ cells in culture conditions for lymphoid cell development. Methods: Isolation of The mononuclear cells (MNCs from umbilical cord blood were done with use of Ficollpaque density gradient. We evaluated cultured cord blood mononuclear and CD34+ cells in presece of IL2, IL7 and IL15 at distinct time points during 21 days by using flow cytometry. In this study, we presented the role of IL2, IL7 and IL15 on the expression of mTOR in cord blood cells. Results: mTOR expression were increased in peresence of IL2, IL7 and IL15 in day 14 and afterword reduced. However in persence of IL2 and IL15 expression of mTOR significantly reduced. mTOR expression in CD34+ cells decreased significantly from day7 to day 21 in culture. Conclusion: cytokines play important role in mTOR expression during hematopoiesis and development of cord blood mononuclear cells.

  1. Positive prognostic value of HER2-HER3 co-expression and p-mTOR in gastric cancer patients.

    Science.gov (United States)

    Cao, Guo-Dong; Chen, Ke; Chen, Bo; Xiong, Mao-Ming

    2017-12-12

    The HER2-HER3 heterodimer significantly decreases survival in breast cancer patients. However, the prognostic value of HER2-HER3 overexpression remains unknown in gastric cancer (GC). The expression levels of HER2, HER3, Akt, p-Akt, mTOR and p-mTOR were examined in specimens from 120 GC patients by immunohistochemistry and quantitative reverse transcription-PCR. The associations of HER proteins, PI3K/Akt/mTOR pathway-related proteins, clinicopathological features of GC, and overall survival (OS) were assessed. To comprehensively evaluate the prognostic values of pathway-related proteins, meta-analyses were conducted with STATA 11.0. HER2 overexpression was significantly associated with HER3 levels (P = 0.02). HER3 was highly expressed in gastric cancer tissues. High HER2 and HER3 levels were associated with elevated p-Akt and p-mTOR amounts (P HER2-HER3 co-expression was associated with high p-Akt and p-mTOR (P HER2-HER3 overexpression corresponded to gradually shortened 5-year OS (P HER2-HER3 co-expression may potentially enhance mTOR phosphorylation. HER2-HER3 co-expression and p-mTOR are both related to the prognosis of GC patients.

  2. Chondroitin sulfate proteoglycan-4 does not protect melanoma cells during inhibition of PI3K and mTOR pathways.

    Science.gov (United States)

    Javaid, Sehrish; Terai, Kaoru; Dudek, Arkadiusz Z

    2015-03-01

    Chondroitin sulfate proteoglycan-4 (CSPG4) is commonly expressed in melanoma cells and induces melanoma cell proliferation and migration by enhancement of activation of the extracellular signal-regulated kinase 1, 2 (ERK1,2) pathway. The phosphoinositide 3-kinase (PI3K) -protein kinase B (AKT) and mammalian target of rapamycin (mTOR) pathways are also frequently de-regulated in melanoma. We hypothesized that CSPG4, by sustained activation of PI3K, may reduce the effect of the dual inhibition of PI3K-AKT and mTOR pathways. CSPG4-negative melanoma cell line WM1552C was transfected with CSPG4 and CSPG4 lacking cytoplasmic domain (melanoma-associated chondroitin sulfate proteoglycan (MCSP)ΔCD). To assess the effect of CSPG4 on the mTOR pathway, PF-5212384, a dual PI3K/mTOR inhibitor was used. Cell proliferation and downstream signaling from mTOR was assayed in the presence of CSPG4. Forced CSPG4 expression did not provide any protection to melanoma cells from the pharmacological inhibition of mTOR pathway in vitro. In addition, we demonstrated that inhibition of signaling molecules downstream of AKT and mTOR was not diminished in the presence of CSPG4 when the cells were treated with the PI3K/mTOR inhibitor. CSPG4 expression does not have any impact on survival and signaling activity of melanoma cells during PI3K/mTOR inhibition. Copyright© 2015 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  3. Microwave susceptibility experiments

    Energy Technology Data Exchange (ETDEWEB)

    McConaghy, C.

    1984-05-29

    In certain experimental environments, systems can be affected or damaged by microwave pulses. I have conducted tests at LLNL to understand the phenomenology of microwave susceptibility of system components and subsystem components. To date, my experiments have concentrated on bipolar transistors, similar to what might be used in discrete analog circuits, and on CMOS RAM chips, which might be used in a computer memory system. I observed a decrease in failure energies for both the transistor and the integrated curcuit as I shortened the microwave pulse width. An S band (2.86 GHz) transmit/receive (T/R) tube has also been tested both at S band and at X band (8.16 GHz). The S band pulse had limitations in rise-time from zero power, which had an effect on the amount of power that could be transmitted through the T/R tube, as much as 0.7% of the incident power passed through the tube. All tests were conducted in closed-waveguide or coax test-fixtures, in contrast to the anechoic chambers utilized by other experimenters. I have used both S band and X band Klystron generators. For very high power (greater than 1 MW), I used an additional pulse-compression cavity at S band. Other subsystem components such as an X band mixer and an X band T/R tube will be tested in the future. 8 references.

  4. [Antimicrobial susceptibility cumulative reports].

    Science.gov (United States)

    Canut-Blasco, Andrés; Calvo, Jorge; Rodríguez-Díaz, Juan Carlos; Martínez-Martínez, Luis

    2016-10-01

    Cumulative reports on antimicrobial susceptibility tests data are important for selecting empirical treatments, as an educational tool in programs on antimicrobial use, and for establishing breakpoints defining clinical categories. These reports should be based on data validated by clinical microbiologists using diagnostic samples (not surveillance samples). In order to avoid a bias derived from including several isolates obtained from the same patient, it is recommended that, for a defined period, only the first isolate is counted. A minimal number of isolates per species should be presented: a figure of >=30 isolates is statistically acceptable. The report is usually presented in a table format where, for each cell, information on clinically relevant microorganisms-antimicrobial agents is presented. Depending on particular needs, multiple tables showing data related to patients, samples, services or special pathogens can be prepared. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

  5. Salidroside alleviates cachexia symptoms in mouse models of cancer cachexia via activating mTOR signalling.

    Science.gov (United States)

    Chen, Xiangzheng; Wu, Yangping; Yang, Tinghan; Wei, Mingtian; Wang, Yuxi; Deng, Xiangbing; Shen, Congcong; Li, Wenting; Zhang, Hang; Xu, Weiyong; Gou, Lantu; Zeng, Yong; Zhang, Yonghui; Wang, Ziqiang; Yang, Jinliang

    2016-05-01

    Cachexia has a devastating impact on survival and quality of life for many cancer patients and contributes to nearly one-third of all cancer deaths; also, it is associated with poor responses to chemotherapy and survival. A better understanding of the underlying mechanisms of cancer-associated cachexia (CAC), coupled with effective therapeutic approaches, will improve management of progressive functional impairment in cancer patients. Salidroside, a phenylpropanoid glycoside in Rhodiola rosea L, has been reported to possess potential anti-fatigue, anti-ageing, and anti-Alzheimer's disease properties. It is widely consumed as a nutritional supplement, but its effects on CAC and the possible mechanism remain a mystery. In the murine models of cachexia induced by CT-26 and Lewis lung carcinoma (LLC) tumour, respectively, main features of CAC were determined after treatment of salidroside or chemotherapy. In vitro experiments were performed using murine C2C12 myotubes, which were treated by tumour necrosis factor-α. Levels of several critical muscle-related signal proteins such as mammalian target of rapamycin (mTOR), p-mTOR, and myosin heavy chain (MyHC) were examined using western blot both in vitro and in vivo. In the present study, we showed the exciting effect of salidroside on the treatment of CAC. In CT-26 and LLC models, respectively, salidroside treatment could effectively preserve the tumour-free body weight, decrease loss of adipose and gastrocnemius muscles, alleviate tumour burden, and prolong their survival time. Additionally, in combined chemotherapy, salidroside could synergistically enhance the anti-tumour activity of cisplatin, especially decreased or eliminated chemotherapy-induced cachexia. Further analysis demonstrated that salidroside could significantly increase expression of mTOR, p-mTOR, and MyHC in gastrocnemius muscle. Also, results in vitro showed that salidroside could not only obviously increase mTOR, p-mTOR, and MyHC expression in C2C12

  6. Cholera outbreak caused by drug resistant Vibrio cholerae serogroup O1 biotype ElTor serotype Ogawa in Nepal; a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Pappu Kumar Gupta

    2016-06-01

    Full Text Available Abstract Background Cholera is a major cause of mortality and morbidity in underdeveloped countries including Nepal. Recently drug resistance in Vibrio cholerae has become a serious problem mainly in developing countries. The main objectives of our study were to investigate the occurrence of Vibrio cholerae in stool samples from patients with watery diarrhea and to determine the antimicrobial susceptibility patterns of V. cholerae isolates. Methods A total of 116 stool samples from patients suffering from watery diarrhea during July to December 2012 were obtained from outbreak areas from all over Nepal. Alkaline peptone water and thiosulphate citrate bile salt sucrose agar (TCBS were used to isolate the Vibrio cholerae. The isolates were identified with the help of colony morphology, Gram’s staining, conventional biochemical testing, serotyping and biotyping. Antimicrobial susceptibility testing was performed by determining the minimum inhibitory concentration (MIC by agar dilution method. Results Vibrio cholerae was isolated from 26.72 % of total samples. All isolated Vibrio cholerae were confirmed to be Vibrio cholerae serogoup O1 biotype El Tor and serotype Ogawa. All isolates were resistant to ampicillin and cotrimoxazole. Twenty nine isolates were resistant toward two different classes of antibiotics, one strain was resistant to three different classes of antibiotics and one strain was resistant to four different classes of antibiotics. According to the definition of the multidrug resistant bacteria; 6.45 % of the strains of Vibrio cholerae were found to be multidrug resistant. Conclusions Cholera due to multidrug resistant Vibrio cholerae is also possible in Nepal. According to the antimicrobial susceptibility pattern of Vibrio cholerae in our study we recommend to use any antibiotics among tetracycline, doxycycline, levofloxacin, azithromycin, chloramphenicol and ciprofloxacin for preliminary treatment of cholera in Nepal.

  7. Analýza skryté služby v síti TOR

    OpenAIRE

    Mesík, Vladimír

    2015-01-01

    Táto práca sa zaoberá anonymitou v informačnej dobe, princípom cibuľového smerovania, anonymnou sieťou Tor a princípom fungovania skrytej služby v sieti Tor. Analyzuje bezpečnosť, anonymitu a možnosť deanonymizácie servera skrytej služby, riziko odhalenia jeho skutočnej IP adresy. Popisuje vybrané typy útokov na siet Tor s cieľom deanonymizácie. V praktickej časti popisuje postup inštalácie a konfigurácie skrytej služby v sieti Tor pod linuxom. Záverom praktickej časti je funkčný .onion serve...

  8. mTOR pathway inhibition prevents neuroinflammation and neuronal death in a mouse model of cerebral palsy.

    Science.gov (United States)

    Srivastava, Isha N; Shperdheja, Jona; Baybis, Marianna; Ferguson, Tanya; Crino, Peter B

    2016-01-01

    Mammalian target of rapamycin (mTOR) pathway signaling governs cellular responses to hypoxia and inflammation including induction of autophagy and cell survival. Cerebral palsy (CP) is a neurodevelopmental disorder linked to hypoxic and inflammatory brain injury however, a role for mTOR modulation in CP has not been investigated. We hypothesized that mTOR pathway inhibition would diminish inflammation and prevent neuronal death in a mouse model of CP. Mouse pups (P6) were subjected to hypoxia-ischemia and lipopolysaccharide-induced inflammation (HIL), a model of CP causing neuronal injury within the hippocampus, periventricular white matter, and neocortex. mTOR pathway inhibition was achieved with rapamycin (an mTOR inhibitor; 5mg/kg) or PF-4708671 (an inhibitor of the downstream p70S6kinase, S6K, 75 mg/kg) immediately following HIL, and then for 3 subsequent days. Phospho-activation of the mTOR effectors p70S6kinase and ribosomal S6 protein and expression of hypoxia inducible factor 1 (HIF-1α) were assayed. Neuronal cell death was defined with Fluoro-Jade C (FJC) and autophagy was measured using Beclin-1 and LC3II expression. Iba-1 labeled, activated microglia were quantified. Neuronal death, enhanced HIF-1α expression, and numerous Iba-1 labeled, activated microglia were evident at 24 and 48 h following HIL. Basal mTOR signaling, as evidenced by phosphorylated-S6 and -S6K levels, was unchanged by HIL. Rapamycin or PF-4,708,671 treatment significantly reduced mTOR signaling, neuronal death, HIF-1α expression, and microglial activation, coincident with enhanced expression of Beclin-1 and LC3II, markers of autophagy induction. mTOR pathway inhibition prevented neuronal death and diminished neuroinflammation in this model of CP. Persistent mTOR signaling following HIL suggests a failure of autophagy induction, which may contribute to neuronal death in CP. These results suggest that mTOR signaling may be a novel therapeutic target to reduce neuronal cell death in

  9. A Pan-Cancer Proteogenomic Atlas of PI3K/AKT/mTOR Pathway Alterations | Office of Cancer Genomics

    Science.gov (United States)

    Molecular alterations involving the PI3K/Akt/mTOR pathway (including mutation, copy number, protein, or RNA) were examined across 11,219 human cancers representing 32 major types. Within specific mutated genes, frequency, mutation hotspot residues, in silico predictions, and functional assays were all informative in distinguishing the subset of genetic variants more likely to have functional relevance. Multiple oncogenic pathways including PI3K/Akt/mTOR converged on similar sets of downstream transcriptional targets.

  10. Long-term mTOR inhibitors administration evokes altered calcium homeostasis and platelet dysfunction in kidney transplant patients

    OpenAIRE

    López, Esther; Berna-Erro, Alejandro; Bermejo, Nuria; Brull, José María; Martinez, Rocío; Garcia Pino, Guadalupe; Alvarado, Raul; Salido, Ginés María; Rosado, Juan Antonio; Cubero, Juan José; Redondo, Pedro Cosme

    2013-01-01

    The use of the mammal target of rapamycin (mTOR) inhibitors has been consolidated as the therapy of election for preventing graft rejection in kidney transplant patients, despite their immunosuppressive activity is less strong than anti-calcineurin agents like tacrolimus and cyclosporine A. Furthermore, as mTOR is widely expressed, rapamycin (a macrolide antibiotic produced by Streptomyces hygroscopicus) is recommended in patients presenting neoplasia due to its antiproliferative actions. Hen...

  11. mTOR REGULATES TAU PHOSPHORYLATION AND DEGRADATION: IMPLICATIONS FOR ALZHEIMER’S DISEASE AND OTHER TAUOPATHIES

    Science.gov (United States)

    Caccamo, Antonella; Magrì, Andrea; Medina, David X.; Wisely, Elena V.; López-Aranda, Manuel F.; Silva, Alcino J.; Oddo, Salvatore

    2013-01-01

    SUMMARY Accumulation of tau is a critical event in several neurodegenerative disorders, collectively known as tauopathies, which include Alzheimer’s disease and frontotemporal dementia. Pathological tau is hyperphosphorylated and aggregates to form neurofibrillary tangles. The molecular mechanisms leading to tau accumulation remain unclear and more needs to be done to elucidate them. Age is a major risk factor for all tauopathies, suggesting that molecular changes contributing to the aging process may facilitate tau accumulation and represent common mechanisms across different tauopathies. Here, we use multiple animal models and complementary genetic and pharmacological approaches to show that the mammalian target of rapamycin (mTOR) regulates tau phosphorylation and degradation. Specifically, we show that genetically increasing mTOR activity elevates endogenous mouse tau levels and phosphorylation. Complementary to it, we further demonstrate that pharmacologically reducing mTOR signaling with rapamycin ameliorates tau pathology and the associated behavioral deficits in a mouse model overexpressing mutant human tau. Mechanistically, we provide compelling evidence that the association between mTOR and tau is linked to GSK3β and autophagy function. In summary, we show that increasing mTOR signaling facilitates tau pathology while reducing mTOR signaling ameliorates tau pathology. Given the overwhelming evidence showing that reducing mTOR signaling increases lifespan and health span, the data presented here have profound clinical implications for aging and tauopathies and provide the molecular basis for how aging may contribute to tau pathology. Additionally, these results provide pre-clinical data indicating that reducing mTOR signaling may be a valid therapeutic approach for tauopathies. PMID:23425014

  12. The role of mTOR during cisplatin treatment in an in vitro and ex vivo model of cervical cancer.

    Science.gov (United States)

    Leisching, G R; Loos, B; Botha, M H; Engelbrecht, A-M

    2015-09-01

    Cisplatin is used as a cytotoxic agent for the management of cervical cancer. However, the severity of the side-effects limits the use of this drug, particularly at high doses. Resistance to cisplatin is often attributed to a disruption in the normal apoptotic response via aberrant activation of pathways such as the mTOR pathway. Here we assess the role of mTOR and its effect on cell death sensitization and autophagy in response to a low concentration of cisplatin in cervical cancer cells. Additionally we measured the expression profile of mTOR in normal, low- and high-grade squamous intraepithelial (LSIL and HSIL) lesions and cancerous tissue. An in vitro model of cervical cancer was established using HeLa and CaSki cells. mTOR protein expression as well as autophagy-related proteins were evaluated through Western blotting. Inhibition of mTOR was achieved with the use of rapamycin and RNA silencing. A low concentration of cisplatin administered as a single agent induces autophagy, but not apoptosis. Cisplatin cytotoxicity was greatly enhanced in cancer cells when mTOR had been inhibited prior to cisplatin treatment which was likely due to autophagy being increased above cisplatin-induced levels, thereby inducing apoptosis. Cervical tissue samples revealed an increase in mTOR protein expression in LSIL and carcinoma tissue which suggests a change in autophagy control. Our data suggest that utilising a lower dose of cisplatin combined with mTOR inhibition is a viable treatment option and addresses the challenge of cisplatin dose-dependent toxicity, however future studies are required to confirm this in a clinical setting. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. mTOR is essential for the proteotoxic stress response, HSF1 activation and heat shock protein synthesis.

    Directory of Open Access Journals (Sweden)

    Shiuh-Dih Chou

    Full Text Available The target of rapamycin (TOR is a high molecular weight protein kinase that regulates many processes in cells in response to mitogens and variations in nutrient availability. Here we have shown that mTOR in human tissue culture cells plays a key role in responses to proteotoxic stress and that reduction in mTOR levels by RNA interference leads to increase sensitivity to heat shock. This effect was accompanied by a drastic reduction in ability to synthesize heat shock proteins (HSP, including Hsp70, Hsp90 and Hsp110. As HSP transcription is regulated by heat shock transcription factor 1 (HSF1, we examined whether mTOR could directly phosphorylate this factor. Indeed, we determined that mTOR could directly phosphorylate HSF1 on serine 326, a key residue in transcriptional activation. HSF1 was phosphorylated on S326 immediately after heat shock and was triggered by other cell stressors including proteasome inhibitors and sodium arsenite. Null mutation of S326 to alanine led to loss of ability to activate an HSF1-regulated promoter-reporter construct, indicating a direct role for mTOR and S326 in transcriptional regulation of HSP genes during stress. As mTOR is known to exist in at least two intracellular complexes, mTORC1 and mTOR2 we examined which complex might interact with HSF1. Indeed mTORC1 inhibitor rapamycin prevented HSF1-S326 phosphorylation, suggesting that this complex is involved in HSF1 regulation in stress. Our experiments therefore suggest a key role for mTORC1 in transcriptional responses to proteotoxic stress.

  14. BMAL1-dependent regulation of the mTOR signaling pathway delays aging.

    Science.gov (United States)

    Khapre, Rohini V; Kondratova, Anna A; Patel, Sonal; Dubrovsky, Yuliya; Wrobel, Michelle; Antoch, Marina P; Kondratov, Roman V

    2014-01-01

    The circadian clock, an internal time-keeping system, has been linked with control of aging, but molecular mechanisms of regulation are not known. BMAL1 is a transcriptional factor and core component of the circadian clock; BMAL1 deficiency is associated with premature aging and reduced lifespan. Here we report that activity of mammalian Target of Rapamycin Complex 1 (mTORC1) is increased upon BMAL1 deficiency both in vivo and in cell culture. Increased mTOR signaling is associated with accelerated aging; in accordance with that, treatment with the mTORC1 inhibitor rapamycin increased lifespan of Bmal1-/- mice by 50%. Our data suggest that BMAL1 is a negative regulator of mTORC1 signaling. We propose that the circadian clock controls the activity of the mTOR pathway through BMAL1-dependent mechanisms and this regulation is important for control of aging and metabolism.

  15. Mechanical characterisation of the TorPeDO: a low frequency gravitational force sensor

    Science.gov (United States)

    McManus, D. J.; Forsyth, P. W. F.; Yap, M. J.; Ward, R. L.; Shaddock, D. A.; McClelland, D. E.; Slagmolen, B. J. J.

    2017-07-01

    Newtonian noise is likely to be a future challenge at low frequencies for Advanced LIGO and other second generation gravitational wave detectors. We present the TorPeDO system: a dual torsion pendulum sensor designed to measure local gravitational forces to high precision. Gravitational forces induce a differential rotation between the two torsion beams, which is measured with an optical read-out. Both torsion pendulums have a common suspension point, tunable centre of mass, and resonant frequency. This produces a high level of mechanical common mode noise cancellation. We report on a controls prototype of the TorPeDO system, presenting the frequency response and tuning range of both pendulums. A noise budget and mechanical cross-coupling model for this system are also presented. We demonstrate frequency tuning of the two torsion pendulums to a difference of 4.3 μHz.

  16. AKTivation of the PI3K/AKT/mTOR signaling pathway by KSHV

    Directory of Open Access Journals (Sweden)

    Aadra P Bhatt

    2013-01-01

    Full Text Available As an obligate intracellular parasite, the Kaposi sarcoma-associated herpesvirus (KSHV relies on host cell machinery to meet its needs for survival, viral replication, production, and dissemination of progeny virions. KSHV is a ɣ-herpesvirus that is associated with three different malignancies: Kaposi sarcoma (KS, and two B cell lymphoproliferative disorders, primary effusion lymphoma (PEL and multicentric Castleman disease (MCD. KSHV viral proteins modulate cellular phosphatidylinositol-3-kinase (PI3K/AKT/mammalian target of rapamycin (mTOR signaling pathway, which is a ubiquitous pathway that also controls B lymphocyte proliferation and development. We review the mechanisms by which KSHV manipulates the PI3K/AKT/mTOR pathway, with a specific focus on B cells.

  17. Circuit-extension handshakes for Tor achieving forward secrecy in a quantum world

    Directory of Open Access Journals (Sweden)

    Schanck John M.

    2016-10-01

    Full Text Available We propose a circuit extension handshake for Tor that is forward secure against adversaries who gain quantum computing capabilities after session negotiation. In doing so, we refine the notion of an authenticated and confidential channel establishment (ACCE protocol and define pre-quantum, transitional, and post-quantum ACCE security. These new definitions reflect the types of adversaries that a protocol might be designed to resist. We prove that, with some small modifications, the currently deployed Tor circuit extension handshake, ntor, provides pre-quantum ACCE security. We then prove that our new protocol, when instantiated with a post-quantum key encapsulation mechanism, achieves the stronger notion of transitional ACCE security. Finally, we instantiate our protocol with NTRU-Encrypt and provide a performance comparison between ntor, our proposal, and the recent design of Ghosh and Kate.

  18. Differential virulence of Candida albicans and C. dubliniensis: A role for Tor1 kinase?

    LENUS (Irish Health Repository)

    Sullivan, Derek J

    2011-01-01

    Candida albicans and Candida dubliniensis are two very closely related species of pathogenic yeast. C. albicans is the most prevalent species in the human gastrointestinal tract and is responsible for far more opportunistic infections in comparison with C. dubliniensis. This disparity is likely to be due to the reduced ability of C. dubliniensis to undergo the yeast to hypha transition, a change in morphology that plays an important role in C. albicans virulence. We have recently shown that hypha formation by C. dubliniensis is specifically repressed by nutrients at alkaline pH. In this article, we present new data showing that this can be partly reversed by treatment with rapamycin, an inhibitor of the nutrient sensing kinase Tor1 (Target Of Rapamycin). We also provide a speculative model to describe why C. albicans filaments more efficiently in nutrient rich environments, citing recently described data on Mds3, a pH responsive regulator of Tor1 kinase activity.

  19. Autophagy response: manipulating the mTOR-controlled machinery by amino acids and pathogens.

    Science.gov (United States)

    Fader, Claudio Marcelo; Aguilera, Milton Osmar; Colombo, María Isabel

    2015-10-01

    Macroautophagy is a self-degradative process that normally maintains cellular homeostasis via a lysosomal pathway. It is induced by different stress signals, including nutrients and growth factors' restriction as well as pathogen invasions. These stimuli are modulated by the serine/threonine protein kinase mammalian target of rapamycin (mTOR) which control not only autophagy but also protein translation and gene expression. This review focuses on the important role of mTOR as a master regulator of cell growth and the autophagy pathway. Here, we have discussed the role of intracellular amino acid availability and intracellular pH in the redistribution of autophagic structures, which may contribute to mammalian target of rapamycin complex 1 (mTORC1) activity regulation. We have also discussed that mTORC1 complex and components of the autophagy machinery are localized at the lysosomal surface, representing a fascinating mechanism to control the metabolism, cellular clearance and also to restrain invading intracellular pathogens.

  20. mTOR: A Link from the Extracellular Milieu to Transcriptional Regulation of Oligodendrocyte Development

    Directory of Open Access Journals (Sweden)

    Teresa L. Wood

    2013-02-01

    Full Text Available Oligodendrocyte development is controlled by numerous extracellular signals that regulate a series of transcription factors that promote the differentiation of oligodendrocyte progenitor cells to myelinating cells in the central nervous system. A major element of this regulatory system that has only recently been studied is the intracellular signalling from surface receptors to transcription factors to down-regulate inhibitors and up-regulate inducers of oligodendrocyte differentiation and myelination. The current review focuses on one such pathway: the mTOR (mammalian target of rapamycin pathway, which integrates signals in many cell systems and induces cell responses including cell proliferation and cell differentiation. This review describes the known functions of mTOR as they relate to oligodendrocyte development, and its recently discovered impact on oligodendrocyte differentiation and myelination. A potential model for its role in oligodendrocyte development is proposed.

  1. Spinster is required for autophagic lysosome reformation and mTOR reactivation following starvation.

    Science.gov (United States)

    Rong, Yueguang; McPhee, Christina K; McPhee, Christina; Deng, Shuangshen; Huang, Lei; Chen, Lilian; Liu, Mei; Tracy, Kirsten; Baehrecke, Eric H; Baehreck, Eric H; Yu, Li; Lenardo, Michael J

    2011-05-10

    Autophagy is a conserved cellular process to degrade and recycle cytoplasmic components. During autophagy, lysosomes fuse with an autophagosome to form an autolysosome. Sequestered components are degraded by lysosomal hydrolases and presumably released into the cytosol by lysosomal efflux permeases. Following starvation-induced autophagy, lysosome homeostasis is restored by autophagic lysosome reformation (ALR) requiring activation of the "target of rapamycin" (TOR) kinase. Spinster (Spin) encodes a putative lysosomal efflux permease with the hallmarks of a sugar transporter. Drosophila spin mutants accumulate lysosomal carbohydrates and enlarged lysosomes. Here we show that defects in spin lead to the accumulation of enlarged autolysosomes. We find that spin is essential for mTOR reactivation and lysosome reformation following prolonged starvation. Further, we demonstrate that the sugar transporter activity of Spin is essential for ALR.

  2. Rapalogs and mTOR inhibitors as anti-aging therapeutics.

    Science.gov (United States)

    Lamming, Dudley W; Ye, Lan; Sabatini, David M; Baur, Joseph A

    2013-03-01

    Rapamycin, an inhibitor of mechanistic target of rapamycin (mTOR), has the strongest experimental support to date as a potential anti-aging therapeutic in mammals. Unlike many other compounds that have been claimed to influence longevity, rapamycin has been repeatedly tested in long-lived, genetically heterogeneous mice, in which it extends both mean and maximum life spans. However, the mechanism that accounts for these effects is far from clear, and a growing list of side effects make it doubtful that rapamycin would ultimately be beneficial in humans. This Review discusses the prospects for developing newer, safer anti-aging therapies based on analogs of rapamycin (termed rapalogs) or other approaches targeting mTOR signaling.

  3. Comparison of different tube-of-response (TOR) models for resolution recovery in PET image reconstruction for the Philips Ingenuity TF PET/MR

    Energy Technology Data Exchange (ETDEWEB)

    Lougovski, Alexandr; Hofheinz, Frank; Van Den Hoff, Jorg [Helmholtz-Center Dresden-Rossendorf, Institute of Radiopharmaceutical Cancer Research, PET Center, Dresden (Germany)

    2015-05-18

    Recently, we have proposed a method for on-the-fly system matrix computation where the tube-of-response (TOR) is approximated as a cylinder with constant density (TORCD) and the cubic voxels are replaced by spheres. We could show that with this model the PET image quality can be notably improved compared to the vendor provided image reconstruction of our Philips Ingenuity-TF PET/MR. In this work we address the question whether image quality can be further improved by using a variable density TOR (TOR-VD). The radial variability of TOR-VD was modelled by a Kaiser-Bessel function. Free parameters of this density model were used to optimize image properties regarding resolution, noise, and Gibbs artifacts. Additional, a TOR-VD model accounting for position dependent effects along the TOR caused by the finite solid angles of the detectors is under investigation. Phantom measurement were performed with a Philips Ingenuity-TF PET/MR scanner. Listmode data were reconstructed using TOR-CD and TORVD, respectively on two different grids with cubic voxel size of 2 mm and 4 mm. Image quality was assessed with resolution-noise curves and investigation of the radial position dependence of the spatial resolution. For 2 mm voxels, TOR-VD consistently yields a slight improvement of the investigated image quality measures compared to TOR-CD. For 4 mm voxels both models lead essentially to the same results. These findings can be understood as a consequence of the relative size of voxel and TOR. For typical whole body studies (4 mm voxel size) a variable TOR does not improve image quality beyond what is achievable with a constant density TOR. For smaller voxel size the image quality can indeed be somewhat improved with a variable TOR but at the expense of drastically increased computation time.

  4. Identification of Atypical El TorV. cholerae O1 Ogawa Hosting SXT Element in Senegal, Africa

    Directory of Open Access Journals (Sweden)

    Bissoume Sambe-Ba

    2017-05-01

    Full Text Available Vibrio cholerae O1 is the causative agent of cholera with classical and El Tor, two well-established biotypes. In last 20 years, hybrid strains of classical and El Tor and variant El Tor which carry classical ctxB have emerged worldwide. In 2004–2005, Senegal experienced major cholera epidemic with a number of cases totalling more than 31719 with approximately 458 fatal outcomes (CFR, 1.44%. In this retrospective study, fifty isolates out of a total of 403 V. cholerae biotype El Tor serovar Ogawa isolates from all areas in Senegal during the 2004–2005 cholera outbreak were randomly selected. Isolates were characterized using phenotypic and genotypic methods. The analysis of antibiotic resistance patterns revealed the predominance of the S-Su-TCY-Tsu phenotype (90% of isolates. The molecular characterization of antibiotic resistance revealed the presence of the SXT element, a self-transmissible chromosomally integrating element in all isolates. Most of V. cholerae isolates had an intact virulence cassette (86% (ctx, zot, ace genes. All isolates tested gave amplification with primers for classical CT, and 10/50 (20% of isolates carried classical and El Tor ctxB. The study reveals the presence of atypical V. cholerae O1 El Tor during cholera outbreak in Senegal in 2004–2005.

  5. Identification of Atypical El TorV. cholerae O1 Ogawa Hosting SXT Element in Senegal, Africa.

    Science.gov (United States)

    Sambe-Ba, Bissoume; Diallo, Mamadou H; Seck, Abdoulaye; Wane, Abdoul A; Constantin de Magny, Guillaume; Boye, Cheikh S-B; Sow, Ahmad I; Gassama-Sow, Amy

    2017-01-01

    Vibrio cholerae O1 is the causative agent of cholera with classical and El Tor, two well-established biotypes. In last 20 years, hybrid strains of classical and El Tor and variant El Tor which carry classical ctxB have emerged worldwide. In 2004-2005, Senegal experienced major cholera epidemic with a number of cases totalling more than 31719 with approximately 458 fatal outcomes (CFR, 1.44%). In this retrospective study, fifty isolates out of a total of 403 V. cholerae biotype El Tor serovar Ogawa isolates from all areas in Senegal during the 2004-2005 cholera outbreak were randomly selected. Isolates were characterized using phenotypic and genotypic methods. The analysis of antibiotic resistance patterns revealed the predominance of the S-Su-TCY-Tsu phenotype (90% of isolates). The molecular characterization of antibiotic resistance revealed the presence of the SXT element, a self-transmissible chromosomally integrating element in all isolates. Most of V. cholerae isolates had an intact virulence cassette (86%) (ctx, zot, ace genes). All isolates tested gave amplification with primers for classical CT, and 10/50 (20%) of isolates carried classical and El Tor ctxB. The study reveals the presence of atypical V. cholerae O1 El Tor during cholera outbreak in Senegal in 2004-2005.

  6. Down-regulation of mTOR leads to up-regulation of osteoprotegerin in bone marrow cells

    Energy Technology Data Exchange (ETDEWEB)

    Mogi, Makio, E-mail: makio@dpc.aichi-gakuin.ac.jp [Department of Medicinal Biochemistry, School of Pharmacy, Aichi-Gakuin University, 1-100 Kusumoto, Chikusa, Nagoya, Aichi 464-8650 (Japan); Kondo, Ayami [Department of Medicinal Biochemistry, School of Pharmacy, Aichi-Gakuin University, 1-100 Kusumoto, Chikusa, Nagoya, Aichi 464-8650 (Japan)

    2009-06-19

    Osteoprotegerin (OPG)/osteoclastogenesis inhibitory factor regulates bone mass by inhibiting osteoclastic bone resorption. mTOR, which is the mammalian target of rapamycin, is a kinase and central regulator of cell growth, proliferation, and survival. By using Rapamycin, we studied whether mTOR pathway is associated with OPG protein production in the mouse bone marrow-derived stromal cell line ST2. Rapamycin markedly increased the level of soluble OPG in ST2 cells. This antibiotic treatment resulted in the suppression of phosphorylation of mTOR. Rapamycin had no effects on the proliferation, differentiation, or apoptosis of the cells. Treatment with bone morphogenetic protein-4, which can induce OPG protein in ST2 cells, also resulted in a decrease in the density of the phospho-mTOR-band, suggesting that the suppression of the phospho-mTOR pathway is necessary for OPG production in ST2 cells. Thus, suitable suppression of mTOR phosphorylation is a necessary requirement for OPG production in bone marrow stromal cells.

  7. The Roles of PI3K/AKT/mTOR and MAPK/ERK Signaling Pathways in Human Pheochromocytomas

    Directory of Open Access Journals (Sweden)

    Juan Du

    2016-01-01

    Full Text Available Objectives. The roles of PI3K/AKT/mTOR and MAPK/ERK pathways involved in the pathogenesis of pheochromocytoma and paraganglioma (PPGL were demonstrated mostly by in vitro studies with rat or mouse cells and were mainly studied at transcriptional level. This study aimed to investigate the effect of these pathways on the proliferation of human PPGL cells and the activation of these pathways in PPGLs. Methods. Human PPGL cells were treated with sunitinib and inhibitors of PI3K (LY294002, MEK1/2 (U0126, and mTORC1/2 (AZD8055. Cell proliferation was detected by MTT assay. Protein phosphorylation was detected by Western blotting. Results. In most PPGLs, AKT, ERK1/2, and mTOR were activated. LY294002 (10 μM, U0126 (10 μM, AZD8055 (1 μM, and sunitinib (1 μM inhibited PPGL cell proliferation in ten primary cultures of tissues, including four from patients with gene mutations. MEK1/2 inhibitor decreased mTOR phosphorylation. Inhibition of mTOR reduced phosphorylation of AKT and ERK1/2. Sunitinib inhibited phospho-ERK1/2 and phospho-mTOR. Conclusion. Our study suggested that PI3K/AKT/mTOR and MAPK/ERK signaling pathways play vital roles in human PPGL and are activated in most PPGLs. Inhibiting multiple pathways might be a novel therapeutic approach for PPGLs.

  8. Identification of the Raptor-binding motif on Arabidopsis S6 kinase and its use as a TOR signaling suppressor

    Energy Technology Data Exchange (ETDEWEB)

    Son, Ora; Kim, Sunghan; Hur, Yoon-Sun; Cheon, Choong-Ill, E-mail: ccheon@sookmyung.ac.kr

    2016-03-25

    TOR (target of rapamycin) kinase signaling plays central role as a regulator of growth and proliferation in all eukaryotic cells and its key signaling components and effectors are also conserved in plants. Unlike the mammalian and yeast counterparts, however, we found through yeast two-hybrid analysis that multiple regions of the Arabidopsis Raptor (regulatory associated protein of TOR) are required for binding to its substrate. We also identified that a 44-amino acid region at the N-terminal end of Arabidopsis ribosomal S6 kinase 1 (AtS6K1) specifically interacted with AtRaptor1, indicating that this region may contain a functional equivalent of the TOS (TOR-Signaling) motif present in the mammalian TOR substrates. Transient over-expression of this 44-amino acid fragment in Arabidopsis protoplasts resulted in significant decrease in rDNA transcription, demonstrating a feasibility of developing a new plant-specific TOR signaling inhibitor based upon perturbation of the Raptor-substrate interaction. - Highlights: • Multiple regions on the Arabidopsis Raptor protein were found to be involved in substrate binding. • N-terminal end of the Arabidopsis ribosomal S6 kinase 1 (AtS6K1) was responsible for interacting with AtRaptor1. • The Raptor-interacting fragment of AtS6K1 could be utilized as an effective inhibitor of plant TOR signaling.

  9. Dual PI-3 kinase/mTOR inhibition impairs autophagy flux and induces cell death independent of apoptosis and necroptosis

    Science.gov (United States)

    Button, Robert W.; Vincent, Joseph H.; Strang, Conor J.; Luo, Shouqing

    2016-01-01

    The PI-3 kinase (PI-3K)/mTOR pathway is critical for cell growth and proliferation. Strategies of antagonising this signaling have proven to be detrimental to cell survival. This observation, coupled with the fact many tumours show enhanced growth signaling, has caused dual inhibitors of PI-3K and mTOR to be implicated in cancer treatment, and have thus been studied across various tumour models. Since PI-3K (class-I)/mTOR pathway negatively regulates autophagy, dual inhibitors of PI-3K/mTOR are currently believed to be autophagy activators. However, our present data show that the dual PI-3K/mTOR inhibition (DKI) potently suppresses autophagic flux. We further confirm that inhibition of Vps34/PI3KC3, the class-III PI-3K, causes the blockade to autophagosome-lysosome fusion. Our data suggest that DKI induces cell death independently of apoptosis and necroptosis, whereas autophagy perturbation by DKI may contribute to cell death. Given that autophagy is critical in cellular homeostasis, our study not only clarifies the role of a dual PI-3K/mTOR inhibitor in autophagy, but also suggests that its autophagy inhibition needs to be considered if such an agent is used in cancer chemotherapy. PMID:26814436

  10. [Antimicrobial susceptibility in Chile 2012].

    Science.gov (United States)

    Cifuentes-D, Marcela; Silva, Francisco; García, Patricia; Bello, Helia; Briceño, Isabel; Calvo-A, Mario; Labarca, Jaime

    2014-04-01

    Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

  11. Resistance exercise increases leg muscle protein synthesis and mTOR signalling independent of sex

    Science.gov (United States)

    Dreyer, Hans C.; Fujita, Satoshi; Glynn, Erin L.; Drummond, Micah J.; Volpi, Elena; Rasmussen, Blake B.

    2010-01-01

    Aim Sex differences are evident in human skeletal muscle as the cross-sectional area of individual muscle fibres is greater in men as compared to women. We have recently shown that resistance exercise stimulates mTOR signalling and muscle protein synthesis in humans during early post-exercise recovery. Therefore, the aim of this study was to determine if sex influences the muscle protein synthesis response during recovery from resistance exercise. Methods Seventeen subjects, 9 male and 8 female, were studied in the fasted state before, during and for two hours following a bout of high-intensity leg resistance exercise. Mixed muscle protein fractional synthetic rate (FSR) was measured using stable isotope techniques and mTOR signalling was assessed by immunoblotting from repeated vastus lateralis muscle biopsy samples. Results Post-exercise muscle protein synthesis increased by 52% in the men and by 47% in the women (P0.05). Akt phosphorylation increased in both groups at 1 hr post-exercise (P0.05). Phosphorylation of mTOR and its downstream effector S6K1 increased significantly and similarly between groups during post-exercise recovery (P<0.05). eEF2 phosphorylation decreased at 1- and 2 hrs post-exercise (P<0.05) to a similar extent in both groups. Conclusion The contraction-induced increase in early post-exercise mTOR signalling and muscle protein synthesis is independent of sex and appears to not be playing a role in the sexual dimorphism of leg skeletal muscle in young men and women. PMID:20070283

  12. Regulation of the mTOR Pathway by a Novel Rheb Binding Protein BNIP3

    Science.gov (United States)

    2008-05-01

    vivo. Much progress has been made regarding the mechanisms of TORC1 regulation. Tuberous sclerosis complex (TSC) is a genetic disease characterized...and TORC2, TOR complex 1 and 2, respectively; TSC, tuberous sclerosis complex; TM, transmembrane; BH3, Bcl-2 homol- ogy 3; CD, highly conserved domain...cancers (50–52). In addi- tion, knockdown Bnip3 enables breast cancer metastases in the lung, liver, and bone (53). In this study, we identified Bnip3 as a

  13. Putrescine stimulates the mTOR signaling pathway and protein synthesis in porcine trophectoderm cells.

    Science.gov (United States)

    Kong, Xiangfeng; Wang, Xiaoqiu; Yin, Yulong; Li, Xilong; Gao, Haijun; Bazer, Fuller W; Wu, Guoyao

    2014-11-01

    Insufficient placental growth is a major factor contributing to intrauterine growth retardation in mammals. There is growing evidence that putrescine produced from arginine (Arg) and proline via ornithine decarboxylase is a key regulator of angiogenesis, embryogenesis, as well as placental and fetal growth. However, the underlying mechanisms are largely unknown. The present study tested the hypothesis that putrescine stimulates protein synthesis by activating the mechanistic target of rapamycin (mTOR) signaling pathway in porcine trophectoderm cell line 2 cells. The cells were cultured for 2 to 4 days in customized Arg-free Dulbecco modified Eagle Ham medium containing 0, 10, 25, or 50 μM putrescine or 100 μM Arg. Cell proliferation, protein synthesis, and degradation, as well as the abundance of total and phosphorylated mTOR, ribosomal protein S6 kinase 1, and eukaryotic initiation factor 4E-binding protein-1 (4EBP1), were determined. Our results indicate that putrescine promotes cell proliferation and protein synthesis in a dose- and time-dependent manner, which was inhibited by difluoro-methylornithine (an inhibitor of ornithine decarboxylase). Moreover, supplementation of culture medium with putrescine increased the abundance of phosphorylated mTOR and its downstream targets, 4EBP1 and p70 S6K1 proteins. Collectively, these findings reveal a novel and important role for putrescine in regulating the mTOR signaling pathway in porcine placental cells. We suggest that dietary supplementation with or intravenous administration of putrescine may provide a new and effective strategy to improve survival and growth of embryos/fetuses in mammals. © 2014 by the Society for the Study of Reproduction, Inc.

  14. mTOR is necessary for proper satellite cell activity and skeletal muscle regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengpeng [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Liang, Xinrong; Shan, Tizhong [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); Jiang, Qinyang [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States); College of Animal Science and Technology, Guangxi University, Nanning 530004 (China); Deng, Changyan [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Zheng, Rong, E-mail: zhengrong@mail.hzau.edu.cn [Key Laboratory of Swine Genetics and Breeding of Agricultural Ministry & Key Laboratory of Agricultural Animal Genetics, Breeding and Reproduction of Ministry of Education, College of Animal Science and Technology, Huazhong Agricultural University, Wuhan 430070 (China); Kuang, Shihuan, E-mail: skuang@purdue.edu [Department of Animal Sciences, Purdue University, West Lafayette, IN 47907 (United States)

    2015-07-17

    The serine/threonine kinase mammalian target of rapamycin (mTOR) is a key regulator of protein synthesis, cell proliferation and energy metabolism. As constitutive deletion of Mtor gene results in embryonic lethality, the function of mTOR in muscle stem cells (satellite cells) and skeletal muscle regeneration remains to be determined. In this study, we established a satellite cell specific Mtor conditional knockout (cKO) mouse model by crossing Pax7{sup CreER} and Mtor{sup flox/flox} mice. Skeletal muscle regeneration after injury was severely compromised in the absence of Mtor, indicated by increased number of necrotic myofibers infiltrated by Evans blue dye, and reduced number and size of regenerated myofibers in the Mtor cKO mice compared to wild type (WT) littermates. To dissect the cellular mechanism, we analyzed satellite cell-derived primary myoblasts grown on single myofibers or adhered to culture plates. The Mtor cKO myoblasts exhibited defective proliferation and differentiation kinetics when compared to myoblasts derived from WT littermates. At the mRNA and protein levels, the Mtor cKO myoblasts expressed lower levels of key myogenic determinant genes Pax7, Myf5, Myod, Myog than did the WT myoblasts. These results suggest that mTOR is essential for satellite cell function and skeletal muscle regeneration through controlling the expression of myogenic genes. - Highlights: • Pax7{sup CreER} was used to delete Mtor gene in satellite cells. • Satellite cell specific deletion of Mtor impairs muscle regeneration. • mTOR is necessary for satellite cell proliferation and differentiation. • Deletion of Mtor leads to reduced expression of key myogenic genes.

  15. Shadow: Running Tor in a Box for Accurate and Efficient Experimentation

    Science.gov (United States)

    2011-09-23

    plug-ins; Eric Chan-Tin, Denis Foo Kune, and Max Schuchard for discussions about Shadow’s design; Chris Wacek for usability feedback; Roger Dingledine...Security Symposium, pages 33–50, 2009. [10] D. Foo Kune, T. Malchow, J. Tyra, N. Hopper, and Y. Kim. The Distributed Virtual Network for High Fidelity Large...scale simulation of Tor: Modelling a Global Passive Adversary. In Proceedings of the 12th Conference on Advances in Computer Science – ASIAN , pages 48

  16. Androgen interacts with exercise through the mTOR pathway to induce skeletal muscle hypertrophy

    Directory of Open Access Journals (Sweden)

    Fanxing Zeng

    2017-12-01

    Full Text Available This study was designed to investigate the effects of exogenous androgen and resistance exercise on skeletal muscle hypertrophy and the role of the mammalian target of rapamycin (mTOR signalling during the process. A total of 24 male Sprague-Dawley rats were randomly assigned to sham operation and dihydrotestosterone (DHT implantation groups with subgroups subjected to sedentary conditions or resistance exercise (SHAM+SED, SHAM+EX, DHT+SED, and DHT+EX. The experimental procedure lasted for 10 days. The mRNA expression of androgen receptor (AR and insulin-like growth factor I (IGF-I, the expression of myosin heavy chain (MHC, as well as the phosphorylation statuses of AR, mTOR, p70 ribosomal S6 kinase (p70S6K, and eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1 were determined in the white gastrocnemius muscle. The cross sectional area and wet mass of the muscle were also measured. The cross sectional area and MHC expression were significantly higher in SHAM+EX, DHT+SED, and DHT+EX than in SHAM+SED. There was no significant difference among groups in muscle mass. The mRNA expression of AR and IGF-I and the phosphorylation of mTOR, p70S6K, and 4EBP1 were significantly increased in DHT+SED and SHAM+EX and were significantly enhanced in DHT+EX compared with either DHT or exercise alone. These data show that DHT causes hypertrophy in skeletal muscle and that exercise has a synergistic effect on DHT-induced hypertrophy. Exercise enhances androgen-induced rapid anabolic action, which involves activation of the mTOR pathway.

  17. Zastosowanie inhibitorów mTOR w wybranych schorzeniach dermatologicznych

    Directory of Open Access Journals (Sweden)

    Karolina Osiecka

    2011-12-01

    Full Text Available Sirolimus, inaczej rapamycyna, i ewerolimus to nowe leki należące dotzw. inhibitorów mTOR, które znalazły zastosowanie głównie w transplantologiijako leki immunosupresyjne. Szlak mTOR, zwany takżekinazą mTOR, odgrywa istotną rolę w kontroli cyklu komórkowego.Aktywacja szlaku mTOR bierze udział w patogenezie niektórych chorób,w tym nowotworowych. Szczególną grupą pacjentów, u którychrapamycyna jest zalecanym lekiem w terapii przeciwnowotworowej,są chorzy po przeszczepieniach narządowych, u których ryzyko rozwojunowotworu jest znamiennie większe. W dermatologii sirolimusi ewerolimus zostały użyte do leczenia stwardnienia guzowategoi łuszczycy. W leczeniu stwardnienia guzowatego rapamycyna stałasię lekiem celowanym, szczególnie u osób, które wymagają przeszczepienianerki w przebiegu tej choroby. W terapii łuszczycy dotychczasnie podjęto próby oceny leczenia sirolimusem czy ewerolimusemw monoterapii. Zastosowano jednak te leki w skojarzeniu z cyklosporyną,w wyniku czego uzyskano zmniejszenie nefrotoksycznościpoprzez możliwość zmniejszenia dawek cyklosporyny. Obecnie pojawiasię coraz więcej danych o wykorzystaniu rapamycyny do leczeniatakże takich schorzeń, jak raki skóry, raki nerki, chłoniaki czy też białaczki.

  18. Regulation of mTOR activity in Snell dwarf and GH receptor gene-disrupted mice.

    Science.gov (United States)

    Dominick, Graham; Berryman, Darlene E; List, Edward O; Kopchick, John J; Li, Xinna; Miller, Richard A; Garcia, Gonzalo G

    2015-02-01

    The involvement of mammalian target of rapamycin (mTOR) in lifespan control in invertebrates, calorie-restricted rodents, and extension of mouse lifespan by rapamycin have prompted speculation that diminished mTOR function may contribute to mammalian longevity in several settings. We show here that mTOR complex-1 (mTORC1) activity is indeed lower in liver, muscle, heart, and kidney tissue of Snell dwarf and global GH receptor (GHR) gene-disrupted mice (GHR-/-), consistent with previous studies. Surprisingly, activity of mTORC2 is higher in fasted Snell and GHR-/- than in littermate controls in all 4 tissues tested. Resupply of food enhanced mTORC1 activity in both controls and long-lived mutant mice but diminished mTORC2 activity only in the long-lived mice. Mice in which GHR has been disrupted only in the liver do not show extended lifespan and also fail to show the decline in mTORC1 and increase in mTORC2 seen in mice with global loss of GHR. The data suggest that the antiaging effects in the Snell dwarf and GHR-/- mice are accompanied by both a decline in mTORC1 in multiple organs and an increase in fasting levels of mTORC2. Neither the lifespan nor mTOR effects appear to be mediated by direct GH effects on liver or by the decline in plasma IGF-I, a shared trait in both global and liver-specific GHR-/- mice. Our data suggest that a more complex pattern of hormonal effects and intertissue interactions may be responsible for regulating both lifespan and mTORC2 function in these mouse models of delayed aging.

  19. Use of laser photomodulation in the evolution of oral mucositis associated to cyclophosphamide, methotrexate, 5-fluouracil - CMF in 5 fluouracil + adriamycin + cyclophosphamide - FAC chemotherapy protocols in patients with breast cancer

    Science.gov (United States)

    de Fátima Lima Ferreira, Maria; de Carvalho, Fabiola Bastos; de Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Santos, Gustavo M. P.; Gesteira, Maria F. M.; Maia, Tereza Cristina Teixeira; Pinheiro, Antônio L. B.

    2013-03-01

    The aim of this study was to evaluate the efficacy of the laser photobiomodulation (FBML) in prevention and treatment of oral mucositis induced by chemotherapy protocols CMF (cyclophosphamide, methotrexate, 5-Fluouracil) and FAC (5 Fluouracil + Adriamycin + Cyclophosphamide) in cancer patients breast. We selected 28 patients treated at the Center for High Complexity (CACON), who underwent 6 cycles of 21 days of treatment, with diagnosis of infiltrating ductal carcinoma (ICD C50.9). Were randomly divided into three groups: Group A - eight patients (Protocol FAC + Dental protocol of CACON + Laser), Group B - 6 patients (Protocol CMF + Dental protocol of CACON + Laser), Group C - was divided into two sub-groups: Group C1 with 8 patients (Control Group 1: FAC + Dental protocol o CACON) and group C2 with 6 patients (control group 2: Protocol CMF + Dental protocol of CACON). Patients in Group A and B were use of preventive FBML 24 hours before the start of chemotherapy cycle, then every 48 hours and was extended up to one week following completion of chemotherapy. The groups A and B, presented oral mucositis grade 0 (64.29%) p = 0.07, grade I (7.14%), grade II (14.29%), grade III (7.14 %), grade IV (7.14%) compared to group C, who presented mucositis grade 0 (35.71%) in the initial evaluation with p = 0.10, grade I (21.43%), grade II (28.57%), grade III (14.29%), grade IV (0.00%), patients who used the FBML as a preventive and therapeutic showed a reduction and pain relief in 42.86%. It is concluded that the low power laser when used preventively or as therapy and showed immediate relief of pain and accelerate tissue repair.

  20. Bicyclic triterpenoid Iripallidal induces apoptosis and inhibits Akt/mTOR pathway in glioma cells

    Directory of Open Access Journals (Sweden)

    Ghosh Sadashib

    2010-06-01

    Full Text Available Abstract Background The highly resistant nature of glioblastoma multiforme (GBM to chemotherapy prompted us to evaluate the efficacy of bicyclic triterpenoid Iripallidal against GBM in vitro. Methods The effect of Iripallidal on proliferation and apoptosis in glioma cell lines was evaluated by MTS, colony formation and caspase-3 activity. The effect of iripallidal to regulate (i Akt/mTOR and STAT3 signaling (ii molecules associated with cell cycle and DNA damage was evaluated by Western blot analysis. The effect of Iripallidal on telomerase activity was also determined. Results Iripallidal (i induced apoptosis, (ii inhibited Akt/mTOR and STAT3 signaling, (iii altered molecules associated with cell cycle and DNA damage, (iv inhibited telomerase activity and colony forming efficiency of glioma cells. In addition, Iripallidal displayed anti-proliferative activity against non-glioma cancer cell lines of diverse origin. Conclusion The ability of Iripallidal to serve as a dual-inhibitor of Akt/mTOR and STAT3 signaling warrants further investigation into its role as a therapeutic strategy against GBM.

  1. A liaison between mTOR signaling, ribosome biogenesis and cancer.

    Science.gov (United States)

    Gentilella, Antonio; Kozma, Sara C; Thomas, George

    2015-07-01

    The ability to translate genetic information into functional proteins is considered a landmark in evolution. Ribosomes have evolved to take on this responsibility and, although there are some differences in their molecular make-up, both prokaryotes and eukaryotes share a common structural architecture and similar underlying mechanisms of protein synthesis. Understanding ribosome function and biogenesis has been the focus of extensive research since the early days of their discovery. In the last decade however, new and unexpected roles have emerged that place deregulated ribosome biogenesis and protein synthesis at the crossroads of pathological settings, particularly cancer, revealing a set of novel cellular checkpoints. Moreover, it is also becoming evident that mTOR signaling, which regulates an array of anabolic processes, including ribosome biogenesis, is often exploited by cancer cells to sustain proliferation through the upregulation of global protein synthesis. The use of pharmacological agents that interfere with ribosome biogenesis and mTOR signaling has proven to be an effective strategy to control cancer development clinically. Here we discuss the most recent findings concerning the underlying mechanisms by which mTOR signaling controls ribosome production and the potential impact of ribosome biogenesis in tumor development. This article is part of a Special Issue entitled: Translation and Cancer. Copyright © 2015. Published by Elsevier B.V.

  2. Does any drug to treat cancer target mTOR and iron hemostasis in neurodegenerative disorders?

    Science.gov (United States)

    Jodeiri Farshbaf, Mohammad; Ghaedi, Kamran

    2017-02-01

    The prevalence of neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and Huntington's disease are increased by age. Alleviation of their symptoms and protection of normal neurons against degeneration are the main aspects of the research to establish novel therapeutic strategies. Iron as the one of most important cation not only play important role in the structure of electron transport chain proteins but also has pivotal duties in cellular activities. But disruption in iron hemostasis can make it toxin to neurons which causes lipid peroxidation, DNA damage and etc. In patients with Alzheimer and Parkinson misbalancing in iron homeostasis accelerate neurodegeneration and cause neuroinflmmation. mTOR as the common signaling pathway between cancer and neurodegenerative disorders controls iron uptake and it is in active form in both diseases. Anti-cancer drugs which target mTOR causes iron deficiency and dual effects of mTOR inhibitors can candidate them as a therapeutic strategy to alleviate neurodegeneration/inflammation because of iron overloading.

  3. Slm35 links mitochondrial stress response and longevity through TOR signaling pathway

    Science.gov (United States)

    Jose, L. Aguilar-Lopez; Laboy, Raymond; Fabiola, Jaimes-Miranda; Garay, Erika; Alexander, DeLuna; Funes, Soledad

    2016-01-01

    In most eukaryotic cells mitochondria are essential organelles involved in a great variety of cellular functions. One of the physiological processes linked to mitochondria is aging, a gradual process of damage accumulation that eventually promotes cell death. Aging depends on a balance between mitochondrial biogenesis, function and degradation. It has been previously shown that Tor1, Sch9 and Ras2 are activated in response to nutrient availability and regulate cell growth and division. A deficiency in any of these genes promotes lifespan extension and cell protection during oxidative and heat shock stress. In this work we report that in Saccharomyces cerevisiae, the uncharacterized mitochondrial protein Slm35 is functionally linked with the TOR signaling pathway. A Δtor1Δslm35 strain shows a severe decrease in lifespan and is unable to contend with oxidative and heat shock stresses. Specifically, this mutant shows decreased catalase activity indicating a misregulation of ROS scavenging mechanisms. In this study we show that Slm35 is also relevant for mitochondrial network dynamics and mitophagy. The results presented here suggest that Slm35 plays an important role connecting mitochondrial function with cytosolic responses and cell adaptation to stress and aging. PMID:27922823

  4. Autophagy inhibits high glucose induced cardiac microvascular endothelial cells apoptosis by mTOR signal pathway.

    Science.gov (United States)

    Zhang, Zheng; Zhang, Shenwei; Wang, Yong; Yang, Ming; Zhang, Ning; Jin, Zhitao; Ding, Liping; Jiang, Wei; Yang, Junke; Sun, Zhimin; Qiu, Chunguang; Hu, Taohong

    2017-08-20

    Cardiac microvascular endothelial cells (CMECs) dysfunction is an important pathophysiological event in the cardiovascular complications induced by diabetes. However, the underlying mechanism is not fully clarified. Autophagy is involved in programmed cell death. Here we investigated the potential role of autophagy on the CMECs injury induced by high glucose. CMECs were cultured in normal or high glucose medium for 6, 12 and 24 h respectively. The autophagy of CMECs was measured by green fluorescence protein (GFP)-LC3 plasmid transfection. Moreover, the apoptosis of CMEC was determined by flow cytometry. Furthermore, 3-Methyladenine (3MA), ATG7 siRNA and rapamycin were administrated to regulate the autophagy state. Moreover, Western blotting assay was performed to measure the expressions of Akt, mTOR, LC3 and p62. High glucose stress decreased the autophagy, whereas increased the apoptosis in CMECs time dependently. Meanwhile, high glucose stress activated the Akt/mTOR signal pathway. Furthermore, autophagy inhibitor, 3-MA and ATG7 siRNA impaired the autophagy and increased the apoptosis in CMECs induced by high glucose stress. Conversely, rapamycin up-regulated the autophagy and decreased the apoptosis in CMECs under high glucose condition. Our data provide evidence that high glucose directly inhibits autophagy, as a beneficial adaptive response to protect CMECs against apoptosis. Furthermore, the autophagy was mediated, at least in part, by mTOR signaling.

  5. Akt/mTOR Role in Human Foetoplacental Vascular Insulin Resistance in Diseases of Pregnancy

    Directory of Open Access Journals (Sweden)

    Roberto Villalobos-Labra

    2017-01-01

    Full Text Available Insulin resistance is characteristic of pregnancies where the mother shows metabolic alterations, such as preeclampsia (PE and gestational diabetes mellitus (GDM, or abnormal maternal conditions such as pregestational maternal obesity (PGMO. Insulin signalling includes activation of insulin receptor substrates 1 and 2 (IRS1/2 as well as Src homology 2 domain-containing transforming protein 1, leading to activation of 44 and 42 kDa mitogen-activated protein kinases and protein kinase B/Akt (Akt signalling cascades in the human foetoplacental vasculature. PE, GDM, and PGMO are abnormal conditions coursing with reduced insulin signalling, but the possibility of the involvement of similar cell signalling mechanisms is not addressed. This review aimed to determine whether reduced insulin signalling in PE, GDM, and PGMO shares a common mechanism in the human foetoplacental vasculature. Insulin resistance in these pathological conditions results from reduced Akt activation mainly due to inhibition of IRS1/2, likely due to the increased activity of the mammalian target of rapamycin (mTOR resulting from lower activity of adenosine monophosphate kinase. Thus, a defective signalling via Akt/mTOR in response to insulin is a central and common mechanism of insulin resistance in these diseases of pregnancy. In this review, we summarise the cell signalling mechanisms behind the insulin resistance state in PE, GDM, and PGMO focused in the Akt/mTOR signalling pathway in the human foetoplacental endothelium.

  6. Acupuncture promotes mTOR-independent autophagic clearance of aggregation-prone proteins in mouse brain.

    Science.gov (United States)

    Tian, Tian; Sun, Yanhong; Wu, Huangan; Pei, Jian; Zhang, Jing; Zhang, Yi; Wang, Lu; Li, Bin; Wang, Lihua; Shi, Jiye; Hu, Jun; Fan, Chunhai

    2016-01-21

    Acupuncture has historically been practiced to treat medical disorders by mechanically stimulating specific acupoints with fine needles. Despite its well-documented efficacy, its biological basis remains largely elusive. In this study, we found that mechanical stimulation at the acupoint of Yanglingquan (GB34) promoted the autophagic clearance of α-synuclein (α-syn), a well known aggregation-prone protein closely related to Parkinson's disease (PD), in the substantia nigra par compacta (SNpc) of the brain in a PD mouse model. We found the protein clearance arose from the activation of the autophagy-lysosome pathway (ALP) in a mammalian target of rapamycin (mTOR)-independent approach. Further, we observed the recovery in the activity of dopaminergic neurons in SNpc, and improvement in the motor function at the behavior level of PD mice. Whereas acupuncture and rapamycin, a chemical mTOR inhibitor, show comparable α-syn clearance and therapeutic effects in the PD mouse model, the latter adopts a distinctly different, mTOR-dependent, autophagy induction process. Due to this fundamental difference, acupuncture may circumvent adverse effects of the rapamycin treatment. The newly discovered connection between acupuncture and autophagy not only provides a new route to understanding the molecular mechanism of acupuncture but also sheds new light on cost-effective and safe therapy of neurodegenerative diseases.

  7. Regulation of mTOR by mechanically induced signaling events in skeletal muscle.

    Science.gov (United States)

    Hornberger, Troy Alan; Sukhija, Kunal Balu; Chien, Shu

    2006-07-01

    Mechanical stimuli play a major role in the regulation of skeletal muscle mass, and the maintenance of muscle mass contributes significantly to disease prevention and the quality of life. Although a link between mechanical stimuli and the regulation of muscle mass has been recognized for decades, the mechanisms involved in converting mechanical information into the molecular events that control this process have not been defined. Nevertheless, significant advancements are being made in this field, and it has recently been established that signaling through a rapamycin-sensitive pathway is necessary for mechanically induced growth of skeletal muscle. Since rapamycin is a highly specific inhibitor of a protein kinase called the mammalian target of rapamycin (mTOR), many investigators have concluded that mTOR signaling is necessary for the mechanically induced growth of skeletal muscle. In this review, we have summarized the current knowledge regarding how mechanical stimuli activate mTOR signaling, discussed the newly discovered role of phospholipase D (PLD) and phosphatidic acid (PA) in this pathway, and considered the potential roles of PLD and PA in the mechanical regulation of skeletal muscle mass.

  8. Translational regulation of GPx-1 and GPx-4 by the mTOR pathway.

    Directory of Open Access Journals (Sweden)

    Emily N Reinke

    Full Text Available Glutathione peroxidase activity was previously determined to be elevated in lymphocytes obtained from patients treated with the Bcr-Abl kinase inhibitor imatinib mesylate. In order to expand upon this observation, the established chronic myelogenous leukemia cell lines KU812 and MEG-01 were treated with imatinib and the effect on several anti-oxidant proteins was determined. The levels of GPx-1 were significantly increased following treatment with imatinib. This increase was not due to altered steady-state mRNA levels, and appeared to be dependent on the expression of Bcr-Abl, as no increases were observed following imatinib treatment of cells that did not express the fusion protein. The nutrient-sensing signaling protein, mammalian target of rapamycin (mTOR, can be activated by Bcr-Abl and its activity regulates the translation of many different proteins. Treatment of those same cells used in the imatinib studies with rapamycin, an inhibitor of mTOR, resulted in elevated GPx-1 and GPx-4 protein levels independent of Bcr-Abl expression. These proteins all belong to the selenoprotein family of peptides that contain the UGA-encoded amino acid selenocysteine. Collectively, these data provide evidence of a novel means of regulating anti-oxidants of the selenoprotein family via the mTOR pathway.

  9. Endocrine responses and acute mTOR pathway phosphorylation to resistance exercise with leucine and whey

    Directory of Open Access Journals (Sweden)

    MT Lane

    2017-02-01

    Full Text Available Leucine ingestion reportedly activates the mTOR pathway in skeletal muscle, contributing to a hypertrophy response. The purpose of the study was to compare the post-resistance exercise effects of leucine and whey protein supplementation on endocrine responses and muscle mTOR pathway phosphorylation. On visit 1, subjects (X±SD; n=20; age=27.8±2.8yrs provided baseline blood samples for analysis of cortisol, glucose and insulin; a muscle biopsy of the vastus lateralis muscle to assess mTOR signaling pathway phosphorylation; and were tested for maximum strength on the leg press and leg extension exercises. For visits 2 and 3, subjects were randomized in a double-blind crossover design to ingest either leucine and whey protein (10g+10g; supplement or a non-caloric placebo. During these visits, 5 sets of 10 repetitions were performed on both exercises, immediately followed by ingestion of the supplement or placebo. Blood was sampled 30 min post-, and a muscle biopsy 45 min post-exercise. Western blots quantified total and phosphorylated proteins. Insulin increased (α<.05 with supplementation with no change in glucose compared to placebo. Relative phosphorylation of AKT and rpS6 were greater with leucine and whey supplementation compared to placebo. Supplementation of leucine and whey protein immediately after heavy resistance exercise increases anabolic signaling in human skeletal muscle.

  10. Experiencia del dolor torácico en la mujer con infarto del miocardio

    Directory of Open Access Journals (Sweden)

    EILLEN MARYIBE MILLÁN

    2009-12-01

    Full Text Available Se presentan los resultados de la investigación " La experiencia del dolor torácico en la mujer con infarto agudo del miocardio" . Es un estudio cualitativo fenomenológico, que indagó sobre la experiencia del dolor torácico de la mujer que ha sufrido un infarto agudo del miocardio. Se realizó con nueve mujeres cuyo promedio de edad era de 52 años, en su mayoría amas de casa, entrevistadas personalmente por la investigadora. Se utilizó el sistema de entrevista a profundidad, siendo la base fundamental del estudio las narraciones de las experiencias ante el fenómeno de interés. El estudio permitió identificar los elementos constitutivos de la experiencia de dolor torácico en la mujer durante el infarto, descritos bajo la perspectiva personal de cada entrevistada. Los resultados de la experiencia del dolor permiten señalar que es compleja, atemorizante, con matices dados por las situaciones y vivencias previas, y se acompaña de sentimientos de temor ante la posibilidad de morir, que comprometen los ámbitos físicos, psicológicos y emocionales de la vida de la mujer.

  11. mTOR/HIF1α-mediated aerobic glycolysis as metabolic basis for trained immunity

    Science.gov (United States)

    Cheng, Shih-Chin; Quintin, Jessica; Cramer, Robert A.; Shepardson, Kelly M.; Saeed, Sadia; Kumar, Vinod; Giamarellos-Bourboulis, Evangelos J; Martens, Joost H.A.; Rao, Nagesha Appukudige; Aghajanirefah, Ali; Manjeri, Ganesh R.; Li, Yang; Ifrim, Daniela C.; Arts, Rob J.W.; van der Meer, Brian M.J.W.; Deen, Peter M.T.; Logie, Colin; O’Neill, Luke A.; Willems, Peter; van de Veerdonk, Frank L.; van der Meer, Jos W.M.; Ng, Aylwin; Joosten, Leo A.B.; Wijmenga, Cisca; Stunnenberg, Hendrik G.; Xavier, Ramnik J.; Netea, Mihai G.

    2014-01-01

    Epigenetic reprogramming of myeloid cells by infection or vaccination, termed trained immunity, confers non-specific protection from secondary infections. We characterized genome-wide transcriptome and histone modification profiles of human monocytes trained with β-glucan and identified induced expression of genes involved in glucose metabolism. Trained monocytes display high glucose consumption, lactate production, and NAD+/NADH ratio, reflecting a shift in the metabolism of trained monocytes with an increase in glycolysis dependent on the activation of mammalian target of rapamycin (mTOR) through a dectin-1/Akt/HIF1α pathway. Inhibition of Akt, mTOR, or HIF1α blocked monocyte induction of trained immunity, whereas the AMPK activator metformin inhibited the innate immune response to fungal infection. Finally, mice with a myeloid cell-specific defect in HIF1α were unable to mount trained immunity against bacterial sepsis. In conclusion, Akt/mTOR/HIF1α-dependent induction of aerobic glycolysis represents the metabolic basis of trained immunity. PMID:25258083

  12. Differential Reponses of Hematopoietic Stem and Progenitor Cells to mTOR Inhibition

    Directory of Open Access Journals (Sweden)

    Aimin Yang

    2015-01-01

    Full Text Available Abnormal activation of the mammalian target of rapamycin (mTOR signaling pathway has been observed in a variety of human cancers. Therefore, targeting of the mTOR pathway is an attractive strategy for cancer treatment and several mTOR inhibitors, including AZD8055 (AZD, a novel dual mTORC1/2 inhibitor, are currently in clinical trials. Although bone marrow (BM suppression is one of the primary side effects of anticancer drugs, it is not known if pharmacological inhibition of dual mTORC1/2 affects BM hematopoietic stem and progenitor cells (HSPCs function and plasticity. Here we report that dual inhibition of mTORC1/2 by AZD or its analogue (KU-63794 depletes mouse BM Lin−Sca-1+c-Kit+ cells in cultures via the induction of apoptotic cell death. Subsequent colony-forming unit (CFU assays revealed that inhibition of mTORC1/2 suppresses the clonogenic function of hematopoietic progenitor cells (HPCs in a dose-dependent manner. Surprisingly, we found that dual inhibition of mTORC1/2 markedly inhibits the growth of day-14 cobblestone area-forming cells (CAFCs but enhances the generation of day-35 CAFCs. Given the fact that day-14 and day-35 CAFCs are functional surrogates of HPCs and hematopoietic stem cells (HSCs, respectively, these results suggest that dual inhibition of mTORC1/2 may have distinct effects on HPCs versus HSCs.

  13. pso.ATION AND ANTIMICROBIAL SUSCEPTIBILITY

    African Journals Online (AJOL)

    isolates vere made using standard methods, Antibiotic susceptibility tests against commonly prescribed ... Acute otitis media is rapid with short .... sensitivity tests. Antimicrobial susceptibility tests: The antimicrobial susceptibility patterns of major Gram positive and negative bacterial isolates obtained from clinical specimens.

  14. Hypnotic susceptibility and dream characteristics.

    Science.gov (United States)

    Zamore, N; Barrett, D

    1989-11-01

    This study examined the relationship of hypnotic susceptibility to a variety of dream characteristics and types of dream content. A Dream Questionnaire was constructed synthesizing Gibson's dream inventory and Hilgard's theoretical conceptions of hypnosis. Employing the Harvard Group Scale of Hypnotic Susceptibility and the Field Inventory for evaluating hypnotic response, several dream dimensions correlated significantly with hypnotizability. For subjects as a whole, the strongest correlates were the frequency of dreams which they believed to be precognitive and out-of-body dreams. Ability to dream on a chosen topic also correlated significantly with hypnotic susceptibility for both genders. For females only, there was a negative correlation of hypnotic susceptibility to flying dreams. Absorption correlated positively with dream recall, ability to dream on a chosen topic, reports of conflict resolution in dreams, creative ideas occurring in dreams, amount of color in dreams, pleasantness of dreams, bizarreness of dreams, flying dreams and precognitive dreams.

  15. Ancestral susceptibility to colorectal cancer

    Czech Academy of Sciences Publication Activity Database

    Huhn, S.; Pardini, Barbara; Naccarati, Alessio; Vodička, Pavel (ed.); Hemminki, K.; Försti, A.

    2012-01-01

    Roč. 27, č. 2 (2012), s. 197-204 ISSN 0267-8357 R&D Projects: GA ČR GA310/07/1430; GA ČR GAP304/10/1286 Grant - others:EU FP7(XE) HEALTH-F4-2007-200767 Institutional research plan: CEZ:AV0Z50390512 Keywords : cancer susceptibility * molecular epidemiology * genetic susceptibility Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.500, year: 2012

  16. Inhibitory effect of mTOR activator MHY1485 on autophagy: suppression of lysosomal fusion.

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    Yeon Ja Choi

    Full Text Available Autophagy is a major degradative process responsible for the disposal of cytoplasmic proteins and dysfunctional organelles via the lysosomal pathway. During the autophagic process, cells form double-membraned vesicles called autophagosomes that sequester disposable materials in the cytoplasm and finally fuse with lysosomes. In the present study, we investigated the inhibition of autophagy by a synthesized compound, MHY1485, in a culture system by using Ac2F rat hepatocytes. Autophagic flux was measured to evaluate the autophagic activity. Autophagosomes were visualized in Ac2F cells transfected with AdGFP-LC3 by live-cell confocal microscopy. In addition, activity of mTOR, a major regulatory protein of autophagy, was assessed by western blot and docking simulation using AutoDock 4.2. In the result, treatment with MHY1485 suppressed the basal autophagic flux, and this inhibitory effect was clearly confirmed in cells under starvation, a strong physiological inducer of autophagy. The levels of p62 and beclin-1 did not show significant change after treatment with MHY1485. Decreased co-localization of autophagosomes and lysosomes in confocal microscopic images revealed the inhibitory effect of MHY1485 on lysosomal fusion during starvation-induced autophagy. These effects of MHY1485 led to the accumulation of LC3II and enlargement of the autophagosomes in a dose- and time-dependent manner. Furthermore, MHY1485 induced mTOR activation and correspondingly showed a higher docking score than PP242, a well-known ATP-competitive mTOR inhibitor, in docking simulation. In conclusion, MHY1485 has an inhibitory effect on the autophagic process by inhibition of fusion between autophagosomes and lysosomes leading to the accumulation of LC3II protein and enlarged autophagosomes. MHY1485 also induces mTOR activity, providing a possibility for another regulatory mechanism of autophagy by the MHY compound. The significance of this study is the finding of a novel

  17. Multipoint targeting of the PI3K/mTOR pathway in mesothelioma

    Science.gov (United States)

    Zhou, S; Liu, L; Li, H; Eilers, G; Kuang, Y; Shi, S; Yan, Z; Li, X; Corson, J M; Meng, F; Zhou, H; Sheng, Q; Fletcher, J A; Ou, W-B

    2014-01-01

    Background: Mesothelioma is a notoriously chemotherapy-resistant neoplasm, as is evident in the dismal overall survival for patients with those of asbestos-associated disease. We previously demonstrated co-activation of multiple receptor tyrosine kinases (RTKs), including epidermal growth factor receptor (EGFR), MET, and AXL in mesothelioma cell lines, suggesting that these kinases could serve as novel therapeutic targets. Although clinical trials have not shown activity for EGFR inhibitors in mesothelioma, concurrent inhibition of various activated RTKs has pro-apoptotic and anti-proliferative effects in mesothelioma cell lines. Thus, we hypothesised that a coordinated network of multi-RTK activation contributes to mesothelioma tumorigenesis. Methods: Activation of PI3K/AKT/mTOR, Raf/MAPK, and co-activation of RTKs were evaluated in mesotheliomas. Effects of RTK and downstream inhibitors/shRNAs were assessed by measuring mesothelioma cell viability/growth, apoptosis, activation of signalling intermediates, expression of cell-cycle checkpoints, and cell-cycle alterations. Results: We demonstrate activation of the PI3K/AKT/p70S6K and RAF/MEK/MAPK pathways in mesothelioma, but not in non-neoplastic mesothelial cells. The AKT activation, but not MAPK activation, was dependent on coordinated activation of RTKs EGFR, MET, and AXL. In addition, PI3K/AKT/mTOR pathway inhibition recapitulated the anti-proliferative effects of concurrent inhibition of EGFR, MET, and AXL. Dual targeting of PI3K/mTOR by BEZ235 or a combination of RAD001 and AKT knockdown had a greater effect on mesothelioma proliferation and viability than inhibition of individual activated RTKs or downstream signalling intermediates. Inhibition of PI3K/AKT was also associated with MDM2-p53 cell-cycle regulation. Conclusions: These findings show that PI3K/AKT/mTOR is a crucial survival pathway downstream of multiple activated RTKs in mesothelioma, underscoring that PI3K/mTOR is a compelling target for

  18. The role of mTOR signaling in the regulation of protein synthesis and muscle mass during immobilization in mice.

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    You, Jae-Sung; Anderson, Garrett B; Dooley, Matthew S; Hornberger, Troy A

    2015-09-01

    The maintenance of skeletal muscle mass contributes substantially to health and to issues associated with the quality of life. It has been well recognized that skeletal muscle mass is regulated by mechanically induced changes in protein synthesis, and that signaling by mTOR is necessary for an increase in protein synthesis and the hypertrophy that occurs in response to increased mechanical loading. However, the role of mTOR signaling in the regulation of protein synthesis and muscle mass during decreased mechanical loading remains largely undefined. In order to define the role of mTOR signaling, we employed a mouse model of hindlimb immobilization along with pharmacological, mechanical and genetic means to modulate mTOR signaling. The results first showed that immobilization induced a decrease in the global rates of protein synthesis and muscle mass. Interestingly, immobilization also induced an increase in mTOR signaling, eIF4F complex formation and cap-dependent translation. Blocking mTOR signaling during immobilization with rapamycin not only impaired the increase in eIF4F complex formation, but also augmented the decreases in global protein synthesis and muscle mass. On the other hand, stimulating immobilized muscles with isometric contractions enhanced mTOR signaling and rescued the immobilization-induced decrease in global protein synthesis through a rapamycin-sensitive mechanism that was independent of ribosome biogenesis. Unexpectedly, the effects of isometric contractions were also independent of eIF4F complex formation. Similar to isometric contractions, overexpression of Rheb in immobilized muscles enhanced mTOR signaling, cap-dependent translation and global protein synthesis, and prevented the reduction in fiber size. Therefore, we conclude that the activation of mTOR signaling is both necessary and sufficient to alleviate the decreases in protein synthesis and muscle mass that occur during immobilization. Furthermore, these results indicate that the

  19. Immunohistochemical expression of mTOR in germinal center and nongerminal center group of diffuse large B-cell lymphoma: a clinicopathological study.

    Science.gov (United States)

    Vajpayee, Neerja; Burack, Richard; Wang, Dongliang; Hutchison, Robert E; Gajra, Ajeet

    2015-03-01

    The mammalian target of rapamycin (mTOR) pathway regulates many major cellular processes and is implicated in an increasing number of neoplasms, including lymphoma. We correlated immunohistochemical expression of mTOR with germinal center and nongerminal center phenotype, B cell lymphoma-2 (bcl-2) and cellular homolog of the retroviral v-myconcogene (c-myc) expression, and International Prognostic Index (IPI) score in 31 patients with diffuse large B-cell lymphoma (DLBCL). Virtually all patients in our study with high mTOR scores had a germinal center phenotype. Furthermore within the germinal center subgroup, patients with high mTOR scores were associated with higher IPI scores (P germinal center phenotype of DLBCL, mTOR expression might help identify a subset of patients with potentially more aggressive tumors who might benefit from use of targeted therapy using mTOR inhibitors. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. KERAGAMAN GENETIK IKAN SEMAH (Tor tambroides BLEKER 1854 DI SUNGAI MANNA, BENGKULU DAN SUNGAI SEMANKA, LAMPUNG

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    Arif Wibowo

    2016-03-01

    Full Text Available Ikan semah adalah ikan air tawar Indonesia yang memiliki nilai ekonomis tinggi dan jarang ditemukan, hidup di hulu sungai dengan kondisi perairan yang jernih dan kebutuhan oksigen tinggi. Untuk mempertahankan keberlanjutan ikan semah diperlukan informasi keragaman genetik sampai pada penanda molekuler.Molekul DNA dapat berfungsi menjadi penanda molekular yang mampu mengidentifikasi perbedaan genetik langsung pada level DNA sebagai komponen genetik. Penelitian tentang keragaman genetik ikan semah dilakukan  pada tahun 2011 di Sungai Manna, Bengkulu dan Sungai Semanka, Lampung. Tujuan penelitian adalah untuk mengetahui keragaman genetik dan penanda molekuler ikan semah dari Sungai Manna, Bengkulu dan Sungai Semanka, Lampung. Contoh diambil secara acak,  darah dan jaringan otot ikan semah dari masing-masing spesimen dikoleksi dan diekstraksi menggunakan “Geneaid DNA ekstraksi kit”. Bagian gen mtDNA yang digunakan adalah gen Cytochrome Oxidase Subunit I (COI. Analisis keragaman genetik yang meliputi penanda genetik dan hubungan kekerabatan ikan semah berdasarkan runutan nukleotida dan asam amino, dilakukan menggunakan program MEGA versi 4.0 dengan metode bootstrapped Neighbor Joining dengan 1000 kali pengulangan. Hasil penelitian menunjukkan komposisi basa nukleotida untuk ikan semah dari Sungai Manna dan Semanka mengidentifikasi 4 situs nukleotida yang bervasiasi dan semuanya parsimoni informatif. Basa nukleotida dari gen Cytochrome Oxidase Subunit I (COI dapat dijadikan penanda genetik spesifik antara ikan semah, spesies Tor tambroides  dengan genus Tor yang lain. Tor tambroides yang berasal dari Bengkulu dan Lampung (Indonesia juga memiliki basa nukleotida spesifik yang membedakannya dengan Tor tambroides  dari luar Indonesia, bahkan bisa menjadi penanda genetik spesifik lokasi Bengkulu dan Lampung.   Masher is Indonesian fresh water fish species, has a high economic value and is rarely found in nature. This species inhabit river

  1. Target regulation of PI3K/Akt/mTOR pathway by cannabidiol in treatment of experimental multiple sclerosis.

    Science.gov (United States)

    Giacoppo, Sabrina; Pollastro, Federica; Grassi, Gianpaolo; Bramanti, Placido; Mazzon, Emanuela

    2017-01-01

    This study was aimed to investigate whether treatment with purified cannabidiol (CBD) may counteract the development of experimental multiple sclerosis (MS), by targeting the PI3K/Akt/mTOR pathway. Although the PI3K/Akt/mTOR pathway was found to be activated by cannabinoids in several immune and non-immune cells, currently, there is no data about the effects of CBD in the PI3K/Akt/mTOR activity in MS. Experimental Autoimmune Encephalomyelitis (EAE), the most common model of MS, was induced in C57BL/6 mice by immunization with myelin oligodendroglial glycoprotein peptide (MOG) 35-55 . After EAE onset, which occurs approximately 14days after disease induction, mice were daily intraperitoneally treated with CBD (10mg/kg mouse) and observed for clinical signs of EAE. At 28days from EAE-induction, mice were euthanized and spinal cord tissues were sampled to perform immunohistochemical evaluations and western blot analysis. Our results showed a clear downregulation of the PI3K/Akt/mTOR pathway following EAE induction. CBD treatment was able to restore it, increasing significantly the phosphorylation of PI3K, Akt and mTOR. Also, an increased level of BNDF in CBD-treated mice seems to be involved in the activation of PI3K/Akt/mTOR pathway. In addition, our data demonstrated that therapeutic efficacy of CBD treatment is due to reduction of pro-inflammatory cytokines, like IFN-γ and IL-17 together with an up-regulation of PPARγ. Finally, CBD was found to promote neuronal survival by inhibiting JNK and p38 MAP kinases. These results provide an interesting discovery about the regulation of the PI3K/Akt/mTOR pathway by cannabidiol administration, that could be a new potential therapeutic target for MS management. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Synthesis, characterization and biological evaluation of novel neutral fac-M(CO){sub 3}(SNO) complexes (M=Re, {sup 99m}Tc) bearing the o-methoxyphenylpiperazine moiety

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    Chiotellis, A. [Institute of Radioisotopes, Radiodiagnostic Products, National Centre for Scientific Research ' Demokritos' , 15310 Ag. Paraskevi, Athens (Greece); Tsoukalas, C., E-mail: ctsoukal@rrp.demokritos.gr [Institute of Radioisotopes, Radiodiagnostic Products, National Centre for Scientific Research ' Demokritos' , 15310 Ag. Paraskevi, Athens (Greece); Pelecanou, M. [Institute of Biology, National Centre for Scientific Research ' Demokritos' , 15310 Ag. Paraskevi, Athens (Greece); Pirmettis, I.; Papadopoulos, M. [Institute of Radioisotopes, Radiodiagnostic Products, National Centre for Scientific Research ' Demokritos' , 15310 Ag. Paraskevi, Athens (Greece)

    2012-06-15

    The synthesis, characterization and biological evaluation of two new neutral tricarbonyl fac-M(CO){sub 3}(SNO) (M=Re, {sup 99m}Tc) bearing o-methoxyphenylpiperazine as pharmacophore and S-functionalized cysteine or penicillamine as chelators are reported. Competition binding tests showed good affinity for the 5-HT{sub 1A} receptor (8 and 54 nM for 4a and 4b, respectively). Biodistribution studies in healthy animals showed high initial blood and liver uptake, fast blood and tissue depuration and negligible brain uptake. - Graphical abstract: Two new neutral tricarbonyl fac-M(CO){sub 3}(SNO) (M=Re, {sup 99m}Tc) bearing o-methoxyphenylpiperazine as pharmacophore and S-functionalized cysteine or penicillamine as chelator were synthesized, characterized and evaluated as possible 5-HT{sub 1A} receptor imaging agents. Highlights: Black-Right-Pointing-Pointer S-functionalized cysteine or penicillamine for the 5-HT{sub 1A} receptors are reported. Black-Right-Pointing-Pointer Novel rhenium and technetium-99m tricarbonyl complexes were synthesized and characterized. Black-Right-Pointing-Pointer Competition binding tests showed good affinity for the 5-HT{sub 1A} receptors. Black-Right-Pointing-Pointer The {sup 99m}Tc complexes showed adequate features but negligible brain uptake in mice.

  3. The Effects of Trans- Polyoctylene Rubber (TOR as a Compatibilizer on The Properties of Epoxidized Natural Rubber/Recycled Silicone Catheter (ENR-25/rSC Vulcanizate

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    Dahham Omar S.

    2016-01-01

    Full Text Available In this study, the influence of Trans- Polyoctylene Rubber (TOR as a compatibilizer on the cure characteristics, tensile and physical properties of ENR-25/rSC vulcanizate were determined. Five different loading of TOR (2, 4, 6, 8 and 10 phr were prepared and added into the vulcanizate. Results indicated that the scorch time (t2 and cure time (t90 bacame shorter as TOR increased, while minimum torque (ML and maximum torque (MH increased. The incorporation of TOR with the vulcanizates enhanced the tensile strength (Ts, modulus (M100 crosslinking density and hardness values. However, the elongation at break percentage of compatibilized vulcanizates became lower than uncompatibilized vulcanizates.

  4. Tratamiento endovascular de urgencia con endoprótesis de aneurisma roto disecado de aorta torácica: A propósito de un caso Emergency endovascular treatment with endoprosthesis of ruptured dissected aneurysm of thoracic aorta: Report of one case

    Directory of Open Access Journals (Sweden)

    José Lugo

    2007-12-01

    Full Text Available Los aneurismas de aorta torácica son menos comunes que los aneurismas de aorta abdominal y pueden encontrarse en aorta ascendente, arco aórtico, aorta descendente o en una combinación de estos segmentos. De estos aneurismas el 30% al 40% se originan en la aorta torácica descendente. En los aneurismas de aorta torácica existe una debilidad estructural de la pared de la aorta, que conlleva una dilatación arterial progresiva con eventual ruptura o disección. Aproximadamente, 50% de los aneurismas de aorta torácica son ateroscleróticos y ocurren como resultado de remodelado arterial y dilatación o a raíz de un metabolismo anormal del colágeno. La mayoría de los aneurismas de aorta torácica se descubren por casualidad durante la evaluación de otros problemas médicos. La meta del tratamiento de los aneurismas de aorta torácica, es prevenir la muerte debido a su ruptura. El riesgo de ruptura de los no tratados oscila entre 46% a 74% y la tasa de mortalidad por su ruptura es extremadamente alta. Los aneurismas de gran tamaño, en especial aquellos mayores de 6 cm, son más susceptibles de rupturas que los aneurismas de menor tamaño. El tratamiento endovascular, inicialmente desarrollado para los aneurismas de aorta abdominal, se introdujo en 1992 como una alternativa menos invasiva al tratamiento de cirugía abierta para los aneurismas de la aorta torácica descendente. En la actualidad, el injerto de stent endovascular en la aorta descendente o endoprótesis, recibe mayor atención como alternativa al reparo quirúrgico de los aneurismas de aorta torácica.Thoracic aortic aneurysms are less common than abdominal aortic aneurysms and can be found in ascending aorta, aortic arch, descending aorta or in a combination of these segments. 30% to 40% of these aneurysms are originated in thoracic descending aorta. In thoracic aortic aneurysms there exists a structural wall weakness that leads to a progressive arterial dilation with eventual

  5. Comportamento de parafusos corticais submetidos a ensaio de torção manual e de torção em máquina Behavior of cortical screws submitted to manual torsion assay and automated torsion assay

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    Suraya Gomes Novais Shimano

    2008-01-01

    Full Text Available Parafusos corticais são submetidos a tensões de torção durante sua inserção e retirada. Portanto, um dos objetivos deste trabalho foi avaliar o comportamento mecânico dos parafusos corticais de aço inoxidável, quando submetidos a dois tipos de ensaios de torção, o manual e o realizado em uma máquina de torção. O outro objetivo foi analisar o local da fratura resultante dos dois ensaios, por meio de Microscopia Eletrônica de Varredura. Foram utilizados dez parafusos corticais de aço inoxidável. Cinco parafusos foram submetidos ao ensaio de torção manual e os outros cinco parafusos foram ensaiados em máquina de torção. Foram calculadas suas propriedades e a análise do local da fratura foi feita por Microscopia Eletrônica de Varredura. O ensaio de torção manual mostrou-se impreciso para o cálculo das propriedades mecânicas e, por isso, contra-indicado para a determinação do comportamento mecânico de parafusos corticais de aço inoxidável. A torção na máquina apresentou uma metodologia mais rígida e, portanto com resultados mais confiáveis. As fraturas dos parafusos, tanto do ensaio de torção manual quanto do ensaio de torção na máquina, apresentaram padrões sem distinções.Cortical screws are submitted to torsional forces during its insertion and removal. Therefore, one of the purposes of this research was to evaluate the mechanical behavior of stainless steel cortical screws submitted to manual torsion test and automated torsion test. The secondary objective was to analyze the fracture area with a scanning electron microscope. Ten cortical stainless steel screws have been used. Five screws were submitted to the manual torsion test and five screws were tested on a torsion machine. Their properties were calculated and the fracture area was analyzed. The manual torsion test has shown to be inaccurate for the calculation of mechanical properties. Therefore, it is contraindicated for identifying the

  6. Susceptibility Genes in Thyroid Autoimmunity

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    Yoshiyuki Ban

    2005-01-01

    Full Text Available The autoimmune thyroid diseases (AITD are complex diseases which are caused by an interaction between susceptibility genes and environmental triggers. Genetic susceptibility in combination with external factors (e.g. dietary iodine is believed to initiate the autoimmune response to thyroid antigens. Abundant epidemiological data, including family and twin studies, point to a strong genetic influence on the development of AITD. Various techniques have been employed to identify the genes contributing to the etiology of AITD, including candidate gene analysis and whole genome screening. These studies have enabled the identification of several loci (genetic regions that are linked with AITD, and in some of these loci, putative AITD susceptibility genes have been identified. Some of these genes/loci are unique to Graves' disease (GD and Hashimoto's thyroiditis (HT and some are common to both the diseases, indicating that there is a shared genetic susceptibility to GD and HT. The putative GD and HT susceptibility genes include both immune modifying genes (e.g. HLA, CTLA-4 and thyroid specific genes (e.g. TSHR, Tg. Most likely, these loci interact and their interactions may influence disease phenotype and severity.

  7. Dietary protein sources differentially affect microbiota, mTOR activity and transcription of mTOR signaling pathways in the small intestine.

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    Soumya K Kar

    Full Text Available Dietary protein sources can have profound effects on host-microbe interactions in the gut that are critically important for immune resilience. However more knowledge is needed to assess the impact of different protein sources on gut and animal health. Thirty-six wildtype male C57BL/6J mice of 35 d age (n = 6/group; mean ± SEM body weight 21.9 ± 0.25 g were randomly assigned to groups fed for four weeks with semi synthetic diets prepared with one of the following protein sources containing (300 g/kg as fed basis: soybean meal (SBM, casein, partially delactosed whey powder, spray dried plasma protein, wheat gluten meal and yellow meal worm. At the end of the experiment, mice were sacrificed to collect ileal tissue to acquire gene expression data, and mammalian (mechanistic target of rapamycin (mTOR activity, ileal digesta to study changes in microbiota and serum to measure cytokines and chemokines. By genome-wide transcriptome analysis, we identified fourteen high level regulatory genes that are strongly affected in SBM-fed mice compared to the other experimental groups. They mostly related to the mTOR pathway. In addition, an increased (P < 0.05 concentration of granulocyte colony-stimulating factor was observed in serum of SBM-fed mice compared to other dietary groups. Moreover, by 16S rRNA sequencing, we observed that SBM-fed mice had higher (P < 0.05 abundances of Bacteroidales family S24-7, compared to the other dietary groups. We showed that measurements of genome-wide expression and microbiota composition in the mouse ileum reveal divergent responses to diets containing different protein sources, in particular for a diet based on SBM.

  8. Identification of dysphagia using the Toronto Bedside Swallowing Screening Test (TOR-BSST©): are 10 teaspoons of water necessary?

    Science.gov (United States)

    Martino, Rosemary; Maki, Ellen; Diamant, Nicholas

    2014-06-01

    Dysphagia screening often includes administration of water. This study assessed the accuracy in identifying dysphagia with each additional teaspoon of water. The original research of the TOR-BSST(©) permitted this assessment. Trained nurses from acute and rehabilitation facilities prospectively administered the TOR-BSST(©) to 311 eligible stroke inpatients. A sensitivity analysis was conducted for the water item using 10 teaspoons plus a sip as the standard. The proportion of positive screenings was 59.2% in acute and 38.5% in rehabilitation. Of all four items that form the TOR-BSST(©), the water swallow item contributed to the identification of dysphagia in 42.7% in acute and 29.0% in rehabilitation patients. Across all patients, dysphagia accuracy was that five teaspoons resulted in a sensitivity of 79% (95% confidence interval [CI] = 70-86), eight a sensitivity of 92% (95% CI = 85-96) and 10 a sensitivity of 96% (95% CI = 90-99). Although a primary contributor, the water swallow item alone does not identify all patients with dysphagia. For a water swallow to accurately identify dysphagia, it is critical to administer 10 teaspoons. The TOR-BSST(©) water swallow item contributes largely to the total TOR-BSST(©)'s screening score and in making the test highly accurate and reliable.

  9. Bone Size and Quality Regulation: Concerted Actions of mTOR in Mesenchymal Stromal Cells and Osteoclasts

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    Hongguang Wu

    2017-06-01

    Full Text Available The bone size and quality, acquired during adolescent growth under the influence of anabolic hormones, growth factors, and nutrients, determine the height and bone stability and forecast osteoporosis risks in late life. Yet bone size and quality control mechanisms remain enigmatic. To study the roles of mammalian target of rapamycin (mTOR signaling, sensor of growth factors and nutrients, in bone size and quality regulation, we ablated Tsc1, a suppressor of mTOR, in mesenchymal stromal cells (MSCs, monocytes, or their progenies osteoblasts and osteoclasts. mTOR activation in MSCs, but much less in osteoblasts, increased bone width and mass due to MSC hyperproliferation, but decreased bone length and mineral contents due to defective MSC differentiation. mTOR activation promotes bone mineral accretion by inhibiting osteoclast differentiation and activity directly or via coupling with MSCs. Tuberous sclerosis complex patient studies confirmed these findings. Thus, mTOR regulates bone size via MSCs and bone quality by suppressing catabolic activities of osteoclasts.

  10. Nanosecond Pulsed Electric Fields Enhance the Anti-tumour Effects of the mTOR Inhibitor Everolimus against Melanoma

    Science.gov (United States)

    Dai, Jie; Wu, Shan; Kong, Yan; Chi, Zhihong; Si, Lu; Sheng, Xinan; Cui, Chuanliang; Fang, Jing; Zhang, Jue; Guo, Jun

    2017-01-01

    The PI3K/mTOR/AKT pathway is activated in most melanomas, but mTOR inhibitors used singly have limited activity against advanced melanomas. The application of nanosecond pulsed electric fields (nsPEFs) is a promising cancer therapy approach. In this study, we evaluated the synergistic anti-tumour efficacy of the mTOR inhibitor everolimus in conjunction with nsPEFs against melanoma. The combined treatment of nsPEFs and everolimus gradually decreased cell growth concurrent with nsPEF intensity. nsPEFs alone or combined with everolimus could promote melanoma cell apoptosis, accompanied with a loss in cellular mitochondrial membrane potential and an increase in Ca2+ levels. In vivo experiments showed that a combination of the mTOR inhibitor everolimus and nsPEFs improved the inhibitory effect, and all skin lesions caused by nsPEFs healed in 1 week without any observed adverse effect. Combination treatment induced caspase-dependent apoptosis through the upregulation of the pro-apoptotic factor Bax and downregulation of the anti-apoptotic factor Bcl-2. Everolimus and nsPEFs synergistically inhibited angiogenesis by decreasing the expression of vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR), and CD34. Our findings indicate that nsPEFs in combination with an mTOR inhibitor can be used as a potential treatment approach for advanced melanoma.

  11. mTOR activation is a biomarker and a central pathway to autoimmune disorders, cancer, obesity, and aging.

    Science.gov (United States)

    Perl, Andras

    2015-06-01

    The mechanistic target of rapamycin (mTOR) is a ubiquitous serine/threonine kinase, which plays pivotal roles in integrating growth signals on a cellular level. To support proliferation and survival under stress, two interacting complexes that harbor mTOR, mTORC1 and mTORC2, promote the transcription of genes involved in carbohydrate metabolism and lipogenesis, enhance protein translation, and inhibit autophagy. Although rapamycin was originally developed as an inhibitor of T cell proliferation for preventing organ transplant rejection, its molecular target, mTOR, has been subsequently identified as a central regulator of metabolic cues that drive lineage specification in the immune system. Owing to oxidative stress, the activation of mTORC1 has emerged as a central pathway for the pathogenesis of systemic lupus erythematosus and other autoimmune diseases. Paradoxically, mTORC1 has also been identified as a mediator of the Warburg effect that allows cell survival under hypoxia. Rapamycin and new classes of mTOR inhibitors are being developed to block not only transplant rejection and autoimmunity but also to treat obesity and various forms of cancer. Through preventing these diseases, personalized mTOR blockade holds promise to extend life span. © 2015 New York Academy of Sciences.

  12. DEPTOR-mTOR Signaling Is Critical for Lipid Metabolism and Inflammation Homeostasis of Lymphocytes in Human PBMC Culture

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    Qi-bing Xie

    2017-01-01

    Full Text Available Abnormal immune response of the body against substances and tissues causes autoimmune diseases, such as polymyositis, dermatomyositis, and rheumatoid arthritis. Irregular lipid metabolism and inflammation may be a significant cause of autoimmune diseases. Although much progress has been made, mechanisms of initiation and proceeding of metabolic and inflammatory regulation in autoimmune disease have not been well-defined. And novel markers for the detection and therapy of autoimmune disease are urgent. mTOR signaling is a central regulator of extracellular metabolic and inflammatory processes, while DEP domain-containing mTOR-interacting protein (DEPTOR is a natural inhibitor of mTOR. Here, we report that overexpression of DEPTOR reduces mTORC1 activity in lymphocytes of human peripheral blood mononuclear cells (PBMCs. Combination of DEPTOR overexpression and mTORC2/AKT inhibitors effectively inhibits lipogenesis and inflammation in lymphocytes of PBMC culture. Moreover, DEPTOR knockdown activates mTORC1 and increases lipogenesis and inflammations. Our findings provide a deep insight into the relationship between lipid metabolism and inflammations via DEPTOR-mTOR pathway and imply that DEPTOR-mTOR in lymphocytes of PBMC culture has the potential to be as biomarkers for the detection and therapies of autoimmune diseases.

  13. The mechanical activation of mTOR signaling: an emerging role for late endosome/lysosomal targeting.

    Science.gov (United States)

    Jacobs, Brittany L; Goodman, Craig A; Hornberger, Troy A

    2014-02-01

    It is well recognized that mechanical signals play a critical role in the regulation of skeletal muscle mass, and the maintenance of muscle mass is essential for mobility, disease prevention and quality of life. Furthermore, over the last 15 years it has become established that signaling through a protein kinase called the mammalian (or mechanistic) target of rapamycin (mTOR) is essential for mechanically-induced changes in protein synthesis and muscle mass, however, the mechanism(s) via which mechanical stimuli regulate mTOR signaling have not been defined. Nonetheless, advancements are being made, and an emerging body of evidence suggests that the late endosome/lysosomal (LEL) system might play a key role in this process. Therefore, the purpose of this review is to summarize this body of evidence. Specifically, we will first explain why the Ras homologue enriched in brain (Rheb) and phosphatidic acid (PA) are considered to be direct activators of mTOR signaling. We will then describe the process of endocytosis and its involvement in the formation of LEL structures, as well as the evidence which indicates that mTOR and its direct activators (Rheb and PA) are all enriched at the LEL. Finally, we will summarize the evidence that has implicated the LEL in the regulation of mTOR by various growth regulatory inputs such as amino acids, growth factors and mechanical stimuli.

  14. [Defects in TOR regulatory complexes retard aging and carbonyl/oxidative stress development in yeast Saccharomyces cerevisiae].

    Science.gov (United States)

    Homza, B V; Vasyl'kovs'ka, R A; Semchyshyn, H M

    2014-01-01

    TOR signaling pathway first described in yeast S. cerevisiae is the highly conserved regulator of eukaryotic cell growth, aging and stress resistance. The effect of nitrogen sources, in particular amino acids, on the activity of TOR signaling pathway is well studied, however its relation to carbohydrates is poor understood. The aim of the present study is expanding of our understanding of potential role of TOR regulatory complexes in development of carbonyl/oxidative stress that can result from yeast cultivation on glucose and fructose. It has been shown that the level of alpha-dicarbonyl compounds and protein carbonyl groups increased with time of yeast cultivation and was higher in cells grown on fructose that demonstrated their accelerated aging and carbonyl/oxidative stress development as compared with cells grown on glucose. The strains defective in TOR proteins cultivated in the presence of glucose as well as fructose demonstrated lower markers of the stress and aging than parental strain. Thus these data confirmed the previous conclusion on fructose more potent ability to cause carbonyl/oxidative stress and accelerated aging in S. cerevisiae as compared with glucose. However, defects in TOR regulatory complexes retard aging and development of the stress in yeast independent on the type of carbohydrate in the cultivation medium.

  15. Inherited susceptibility and radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Little, J.B. [Harvard School of Public Health, Boston, MA (United States)

    1997-03-01

    There is continuing concern that some people in the general population may have genetic makeups that place them at particularly high risk for radiation-induced cancer. The existence of such a susceptible subpopulation would have obvious implications for the estimation of risks of radiation exposure. Although it has been long known that familial aggregations of cancer do sometimes occur, recent evidence suggests that a general genetic predisposition to cancer does not exist; most cancers occur sporadically. On the other hand, nearly 10% of the known Mendelian genetic disorders are associated with cancer. A number of these involve a familial predisposition to cancer, and some are characterized by an enhanced susceptibility to the induction of cancer by various physical and chemical carcinogens, including ionizing radiation. Such increased susceptibility will depend on several factors including the frequency of the susceptibility gene in the population and its penetrance, the strength of the predisposition, and the degree to which the cancer incidence in susceptible individuals may be increased by the carcinogen. It is now known that these cancer-predisposing genes may be responsible not only for rare familial cancer syndromes, but also for a proportion of the common cancers. Although the currently known disorders can account for only a small fraction of all cancers, they serve as models for genetic predisposition to carcinogen-induced cancer in the general population. In the present report, the author describes current knowledge of those specific disorders that are associated with an enhanced predisposition to radiation-induced cancer, and discusses how this knowledge may bear on the susceptibility to radiation-induced cancer in the general population and estimates of the risk of radiation exposure.

  16. pitting corrosion susceptibility pitting corrosion susceptibility of aisi ...

    African Journals Online (AJOL)

    eobe

    Abstract. The susceptibility of austenitic (AISI 301) stainless steel to pitting corrosion was evaluated in sodium chloride. (NaCl) solutions ... AISI 301 steel suffers from pitting corrosion in all the investigated solutions. AISI 301 steel suffers from ..... [1] Ijeomah, M.N.C. Elements of Corrosion and Protection. Theory, Auto Century ...

  17. Magnetic Susceptability Measurements in Superconductors

    Science.gov (United States)

    Kim, Jason; Mallory, Kendall; Seim, Ryan

    2000-04-01

    A new undergraduate research facility in magnetic susceptability measurements on superconductors is being developed at the University of Northern Colorado. Initial data measurements of the magnetic susceptability of various superconductors will be presented. These measurements were obtained with a liquid helium/nitrogen dewar that was reassembled for use in this project. The cryostat consists of two separate dewars, the first of which contains liquid nitrogen, the second, liquid helium. The liquid nitrogen dewar is used to keep the helium bath from evaporating off too quickly. Data on the evaporation rates of the two liquids will also be presented.

  18. Dose-dependent Effects of mTOR Inhibition on Weight and Mitochondrial Disease in Mice

    Directory of Open Access Journals (Sweden)

    Simon C Johnson

    2015-07-01

    Full Text Available Rapamycin extends lifespan and attenuates age-related pathologies in mice when administered through diet at 14 parts per million (PPM. Recently, we reported that daily intraperitoneal injection of rapamycin at 8 mg/kg attenuates mitochondrial disease symptoms and progression in the Ndufs4 knockout mouse model of Leigh Syndrome. Although rapamycin is a widely used pharmaceutical agent dosage has not been rigorously examined and no dose-response profile has been established. Given these observations we sought to determine if increased doses of oral rapamycin would result in more robust impact on mTOR driven parameters. To test this hypothesis, we compared the effects of dietary rapamycin at doses ranging from 14 to 378 PPM on growth in control and Ndufs4 knockout mice and on health and survival in the Ndufs4 knockout model. High dose rapamycin was well tolerated, dramatically reduced growth, and overcame gender differences. The highest oral dose, approximately 27-times the dose shown to extend murine lifespan, increased survival in Ndufs4 knockout mice similarly to daily rapamycin injection without observable adverse effects. These findings have broad implications for the effective use of rapamycin in murine studies and for the translational potential of rapamycin in the treatment of mitochondrial disease. This data, further supported by a comparison of available literature, suggests that 14 PPM dietary rapamycin is a sub-optimal dose for targeting mTOR systemically in mice. Our findings suggest that the role of mTOR in mammalian biology may be broadly underestimated when determined through treatment with rapamycin at commonly used doses.

  19. Inhibition of Chondrosarcoma Growth by mTOR Inhibitor in an In Vivo Syngeneic Rat Model

    Science.gov (United States)

    Perez, Jennifer; Decouvelaere, Anne Valérie; Pointecouteau, Thomas; Pissaloux, Daniel; Michot, Jean Philippe; Besse, Anthony; Blay, Jean Yves; Dutour, Aurélie

    2012-01-01

    Background Chondrosarcomas are the second most frequent primary malignant type of bone tumor. No effective systemic treatment has been identified in advanced or adjuvant phases for chondrosarcoma. The aim of the present study was to determine the antitumor effects of doxorubicin and everolimus, an mTOR inhibitor on chondrosarcoma progression. Methods and Findings Doxorubin and/or everolimus were tested in vivo as single agent or in combination in the rat orthotopic Schwarm chondrosarcoma model, in macroscopic phase, as well as with microscopic residual disease. Response to everolimus and/or doxorubicin was evaluated using chondrosarcoma volume evolution (MRI). Histological response was evaluated with % of tumor necrosis, tumor proliferation index, metabolism quantification analysis between the treated and control groups. Statistical analyses were performed using chi square, Fishers exact test. Doxorubicin single agent has no effect of tumor growth as compared to no treatment; conversely, everolimus single agent significantly inhibited tumor progression in macroscopic tumors with no synergistic additive effect with doxorubicin. Everolimus inhibited chondrosarcoma proliferation as evaluated by Ki67 expression did not induce the apoptosis of tumor cells; everolimus reduced Glut1 and 4EBP1 expression. Importantly when given in rats with microscopic residual diseases, in a pseudo neoadjuvant setting, following R1 resection of the implanted tumor, everolimus significantly delayed or prevented tumor recurrence. Conclusions MTOR inhibitor everolimus blocks cell proliferation, Glut1 expression and HIF1a expression, and prevents in vivo chondrosarcoma tumor progression in both macroscopic and in adjuvant phase post R1 resection. Taken together, our preclinical data indicate that mTOR inhibitor may be effective as a single agent in treating chondrosarcoma patients. A clinical trial evaluating mTOr inhibitor as neo-adjuvant and adjuvant therapy in chondrosarcoma patients is

  20. Silencing Nrf2 impairs glioma cell proliferation via AMPK-activated mTOR inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yue [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Wang, Handong, E-mail: njhdwang@hotmail.com [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Wang, Qiang [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Ding, Hui [Department of Neurosurgery, Jinling Hospital, School of Medicine, Southern Medical University (Guangzhou), 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China); Wu, Heming [Department of Neurosurgery, Nanjing Jingdu Hospital, No. 34, Biao 34, Yanggongjing Road, Nanjing 210002, Jiangsu Province (China); Pan, Hao [Department of Neurosurgery, Jinling Hospital, School of Medicine, Nanjing University, 305 East Zhongshan Road, Nanjing 210002, Jiangsu Province (China)

    2016-01-15

    Gliomas are the leading cause of death among adults with primary brain malignancies. Treatment for malignant gliomas remains limited, and targeted therapies have been incompletely explored. Nuclear factor erythroid 2-related factor 2 (Nrf2), a key transcription regulator for antioxidant and detoxification enzymes, is abundantly expressed in cancer cells. In this study, the role and mechanism of Nrf2 in cancer cell proliferation was investigated in multiple glioma cell lines. We first evaluated the expression patterns of Nrf2 in four glioma cell lines and found all four cell lines expressed Nrf2, but the highest level was observed in U251 cells. We further evaluated the biological functions of Nrf2 in U251 glioma cell proliferation by specific inhibition of Nrf2 using short hairpin RNA (shRNA). We found that Nrf2 depletion inhibited glioma cell proliferation. Nrf2 depletion also decreased colony formation in U251 cells stably expressing Nrf2 shRNA compared to scrambled control shRNA. Moreover, suppression of Nrf2 expression could lead to ATP depletion (with concomitant rise in AMP/ATP ratio) and consequently to AMPK-activated mTOR inhibition. Finally, activation of adenosine monophosphate–activated protein kinase (AMPK) by treated with phenformin, an AMPK agonist, can mimic the inhibitory effect of Nrf2 knockdown in U251 cells. In conclusion, our findings will shed light to the role and mechanism of Nrf2 in regulating glioma proliferation via ATP-depletion-induced AMPK activation and consequent mTOR inhibition, a novel insight into our understanding the role and mechanism of Nrf2 in glioma pathoetiology. To our knowledge, this is also the first report to provide a rationale for the implication of cross-linking between Nrf2 and mTOR signaling.

  1. Synergic antiproliferative and antiangiogenic effects of EGFR and mTor inhibitors on pancreatic cancer cells.

    Science.gov (United States)

    Azzariti, Amalia; Porcelli, Letizia; Gatti, Giuliana; Nicolin, Angelo; Paradiso, Angelo

    2008-03-01

    The in vitro efficacy of both EGFR inhibitor gefitinib and mTor inhibitor rapamycin, either administrated alone or in different combination schedules, was analysed in four pancreas cancer cell lines. Both drugs were found to induce cell growth inhibition, apoptosis as well as a slight but stable accumulation of cells in the G0/G1 phase. In all cell lines, neither gefitinib nor rapamycin affected EGFR and the expression of its downstream effectors. By contrast, gefitinib inhibited in a fast and completely way p-EGFR and partially p-Akt while a 3 days-rapamycin exposure resulted in the inhibition of the expression of both mTor and p70S6K. Moreover, after early stimulation, the mTor inhibitor produced a progressive, and almost complete inhibition of p-Akt. The analysis of combined gefitinib and rapamycin administration showed a clear schedule-dependent activity which turned out to be synergic only when gefitinib was given before rapamycin. This synergism seemed to depend on increase of both p-Akt and p70S6K inhibition, the greater the induction of apoptosis, the higher the decrease in cell cycle rate. Moreover, the antiangiogenic activity of the two drugs given in combination was demonstrated by a strong reduction of VEGF release which turned out to be more pronounced in the synergic schedule, and HIF-1alpha inhibition-independent. Our results suggest that the schedule of gefitinib followed by rapamycin, acting at different levels of the EGFR cellular pathway, could induce antitumor and antiangiogenic effects of clinical interest in the pancreas cancer model.

  2. [Role of the mTOR pathway in the central regulation of energy balance].

    Science.gov (United States)

    Haissaguerre, Magalie; Cota, Daniela

    2015-01-01

    The pathway of the mammalian (or mechanistic) target of rapamycin kinase (mTOR) responds to different signals such as nutrients and hormones and regulates many cellular functions as the synthesis of proteins and lipids, mitochondrial activity and the organization of the cytoskeleton. At the cellular level, mTOR forms two distinct complexes: mTORC1 and mTORC2. This review intends to summarize the various recent advances on the role of these two protein complexes in the central regulation of energy balance. mTORC1 activity modulates energy balance and metabolic responses by regulating the activity of neuronal populations, such as those located in the arcuate nucleus of the hypothalamus. Recent studies have shown that activity of the hypothalamic mTORC1 pathway varies according to cell and stimulus types, and that this signaling cascade regulates food intake and body weight in response to nutrients, such as leucine, and hormones like leptin, ghrelin and triiodothyronine. On the other hand, mTORC2 seems to be involved in the regulation of neuronal morphology and synaptic activity. However, its function in the central regulation of the energy balance is less known. Dysregulation of mTORC1 and mTORC2 is described in obesity and type 2 diabetes. Therefore, a better understanding of the molecular mechanisms involved in the regulation of energy balance by mTOR may lead to the identification of new therapeutic targets for the treatment of these metabolic pathologies. © Société de Biologie, 2016.

  3. Cross-communication between histone H3 and H4 acetylation and Akt-mTOR signalling in prostate cancer cells.

    Science.gov (United States)

    Makarević, Jasmina; Tawanaie, Nassim; Juengel, Eva; Reiter, Michael; Mani, Jens; Tsaur, Igor; Bartsch, Georg; Haferkamp, Axel; Blaheta, Roman A

    2014-07-01

    Molecular tumour targeting has significantly improved anti-cancer protocols. Still, the addition of molecular targeting to the treatment regime has not led to a curative breakthrough. Combined mammalian target of Rapamycin (mTOR) and histone deacetylase (HDAC) inhibition has been shown not only to enhance anti-tumour potential, but also to prevent resistance development seen under mono-drug therapy. This investigation was designed to evaluate whether cross-communication exists between mTOR signalling and epigenetic events regulated by HDAC. DU-145 prostate cancer cells were treated with insulin-like growth factor (IGF) to activate the Akt-mTOR cascade or with the HDAC-inhibitor valproic acid (VPA) to induce histone H3 and H4 acetylation (aH3, aH4). Subsequently, mTOR, Rictor, Raptor, p70s6k, Akt (all: total and phosphorylated), H3 and H4 (total and acetylated) were analysed by western blotting. Both techniques revealed a link between mTOR and the epigenetic machinery. IGF activated mTOR, Rictor, Raptor, p70s6k and Akt, but also enhanced aH3 and aH4. Inversely, IGFr blockade and knock-down blocked the Akt-mTOR axis, but simultaneously diminished aH3 and aH4. VPA treatment up-regulated histone acetylation, but also activated mTOR-Akt signalling. HDAC1 and 2 knock-down revealed that the interaction with the mTOR system is initiated by histone H3 acetylation. HDAC-mTOR communication, therefore, is apparent whereby tumour-promoting (Akt/mTOR(high), aH3/aH4(low)) and tumour-suppressing signals (Akt/mTOR(low) , aH3/aH4(high)) are activated in parallel. Combined use of an HDAC- and mTOR inhibitor might then diminish pro-tumour effects triggered by the HDAC- (Akt/mTOR(high)) or mTOR inhibitor (aH3/aH4(low)) alone. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

  4. mTOR mediates human trophoblast invasion through regulation of matrix-remodeling enzymes and is associated with serine phosphorylation of STAT3

    Energy Technology Data Exchange (ETDEWEB)

    Busch, Susann [Placenta-Lab, Department of Obstetrics, Friedrich-Schiller-University Jena, Bachstrasse 18, 07740 Jena (Germany); Renaud, Stephen J. [Department of Anatomy and Cell Biology, Queen' s University, Kingston, Ontario, Canada K7L3N6 (Canada); Schleussner, Ekkehard [Placenta-Lab, Department of Obstetrics, Friedrich-Schiller-University Jena, Bachstrasse 18, 07740 Jena (Germany); Graham, Charles H. [Department of Anatomy and Cell Biology, Queen' s University, Kingston, Ontario, Canada K7L3N6 (Canada); Markert, Udo R., E-mail: markert@med.uni-jena.de [Placenta-Lab, Department of Obstetrics, Friedrich-Schiller-University Jena, Bachstrasse 18, 07740 Jena (Germany)

    2009-06-10

    The intracellular signaling molecule mammalian target of rapamycin (mTOR) is essential for cell growth and proliferation. It is involved in mouse embryogenesis, murine trophoblast outgrowth and linked to tumor cell invasiveness. In order to assess the role of mTOR in human trophoblast invasion we analyzed the in vitro invasiveness of HTR-8/SVneo immortalized first-trimester trophoblast cells in conjunction with enzyme secretion upon mTOR inhibition and knockdown of mTOR protein expression. Additionally, we also tested the capability of mTOR to trigger signal transducer and activator of transcription (STAT)-3 by its phosphorylation status. Rapamycin inhibited mTOR kinase activity as demonstrated with a lower phosphorylation level of the mTOR substrate p70 S6 kinase (S6K). With the use of rapamycin and siRNA-mediated mTOR knockdown we could show that cell proliferation, invasion and secretion of matrix-metalloproteinases (MMP)-2 and -9, urokinase-like plasminogen activator (uPA) and its major physiological uPA inhibitor (PAI)-1 were inhibited. While tyrosine phosphorylation of STAT3 was unaffected by mTOR inhibition and knockdown, serine phosphorylation was diminished. We conclude that mTOR signaling is one major mechanism in a tightly regulated network of intracellular signal pathways including the JAK/STAT system to regulate invasion in human trophoblast cells by secretion of enzymes that remodel the extra-cellular matrix (ECM) such as MMP-2, -9, uPA and PAI-1. Dysregulation of mTOR may contribute to pregnancy-related pathologies caused through impaired trophoblast invasion.

  5. Variaciones en el sitio de desembocadura del conducto torácico

    OpenAIRE

    Jesús Barrueco; Andrés Arcas; Ricardo Gómez

    2006-01-01

    Introducción: El conducto torácico es el tronco colector de todos los linfáticos del cuerpo, excepto la mitad derecha de la cabeza, cuello y; tórax. Nace en la parte superior de la cavidad abdominal, atraviesa el diafragma, pasa por el orificio aórtico, llega al mediastino posterior,; recorre en toda su extensión el tórax, y llegado a la base del cuello, en el lado izquierdo, termina generalmente en el confluente yugulosubclavio.; En este estudio se describen las variaciones determin...

  6. Application of the Tor Vergata Scattering Model to L Band Backscatter During the Corn Growth Cycle

    Science.gov (United States)

    Joseph, A. T.; vanderVelde, R.; ONeill, P. E.; Lang, R.; Gish, T.

    2010-01-01

    At the USDA's Optimizing Production Inputs for Economic and Environmental Enhancement (OPE3) experimental site in Beltsville, Maryland, USA) a field campaign took place throughout the 2002 corn growth cycle from May 10th (emergence of corn crops) to October 2nd (harvest). One of the microwave instruments deployed was the multi-frequency (X-, C- and L-band) quad-polarized (HH, HV, VV, VH) NASA GSFC/George Washington University (GWU) truck mounted radar. During the field campaign, this radar system provided once a week fully polarized C- and L-band (4.75 and 1.6 GHz) backscatter measurements from incidence angle of 15, 35, and 55 degrees. In support of microwave observations, an extensive ground characterization took place, which included measurements of surface roughness, soil moisture, vegetation biomass and morphology. The field conditions during the campaign are characterized by several dry downs with a period of drought in the month of August. Peak biomass the corn canopies was reached on July 24th with a total biomass of approximately 6.5 kg/sq m. This dynamic range in both soil moisture and vegetation conditions within the data set is ideal for the validation of discrete medium vegetation scattering models. In this study, we compare the L band backscatter measurements with simulations by the Tor Vergata model (ferrazzoli and Guerriero 1996). The measured soil moisture, vegetation biomass and most reliably measured vegetation morphological parameters (e.g. number of leaves, number of stems and stem height) were used as input for the Tor Vergata model. The more uncertain model parameters (e.g. surface roughness, leaf thickness) and the stem diameter were optimized using a parameter estimation routine based on the Levenberg-Marquardt algorithm. As cost function for this optimization, the HH and VV polarized backscatter measured and stimulated by the TOR Vergata model for incidence angle of 15, 35, and 55 degrees were used (6 measurements in total). The calibrated

  7. Molecular damage in cancer: an argument for mTOR-driven aging.

    Science.gov (United States)

    Blagosklonny, Mikhail V

    2011-12-01

    Despite common belief, accumulation of molecular damage does not play a key role in aging. Still, cancer (an age-related disease) is initiated by molecular damage. Cancer and aging share a lot in common including the activation of the TOR pathway. But the role of molecular damage distinguishes cancer and aging. Furthermore, an analysis of the role of both damage and aging in cancer argues against "a decline, caused by accumulation of molecular damage" as a cause of aging. I also discuss how random molecular damage, via rounds of multiplication and selection, brings about non-random hallmarks of cancer.

  8. Biological aspects of tambra fish (Tor tambroides Blkr. that exotic and rare for its domestication

    Directory of Open Access Journals (Sweden)

    HARYONO

    2006-04-01

    Full Text Available Tambra (Tor tambroides Blkr. is consumed fish; its exotic size, rare population and expensive price but not yet cultured. The aims of study are to know biological aspects tambra fish, i.e: sexual maturity, fecundity, sexual dimorfism, sex ratio, food habits, parasities and dissease. The results were recorded two levels of sexual maturity that III and IV, fecundity ranges 3,125-8,201 eggs, sex ratio 1:2; sexual dimorfism based on shape and color body, tubercle at cheek and operculum of male, also papilla shape; food habits as omnivorous; founded two species of parasities, i.e. Argulus sp. and Lernea cypriniaceae.

  9. Acute mTOR inhibition induces insulin resistance and alters substrate utilization in vivo

    DEFF Research Database (Denmark)

    Kleinert, Maximilian; Sylow, Lykke; Fazakerley, Daniel J

    2014-01-01

    , but not rapamycin reduced insulin-stimulated glucose uptake into incubated muscles, despite normal GLUT4 translocation in muscle cells. AZD8055 inhibited glycolysis in MEF cells. Abrogation of mTORC2 activity by SIN1 deletion impaired glycolysis and AZD8055 had no effect in SIN1 KO MEFs. Re-expression of wildtype...... SIN1 rescued glycolysis. Glucose intolerance following AZD8055 administration was absent in mice lacking the mTORC2 subunit Rictor in muscle, and in vivo glucose uptake into Rictor-deficient muscle was reduced despite normal Akt activity. Taken together, acute mTOR inhibition is detrimental to glucose...

  10. Antagonistic role of natural compounds in mTOR-mediated metabolic reprogramming.

    Science.gov (United States)

    Cerella, Claudia; Gaigneaux, Anthoula; Dicato, Mario; Diederich, Marc

    2015-01-28

    Cells reprogram their metabolism very early during carcinogenesis; this event is critical for the establishment of other cancer hallmarks. Many oncogenes and tumor suppressor genes control metabolism by interplaying with the existing nutrient-sensing intracellular pathways. Mammalian target of rapamycin, mTOR, is emerging as a collector and sorter of a metabolic network controlling upstream and downstream modulation of these same genes. Natural compounds represent a source of anti-cancer molecules with chemopreventive and therapeutic properties. This review describes selected pathways and genes orchestrating the metabolic reprogramming and discusses the potential of natural compounds to target oncogenic metabolic aberrations. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. Two mTOR inhibitors, rapamycin and Torin 1, differentially regulate iron-induced generation of mitochondrial ROS.

    Science.gov (United States)

    Huang, Hui; Chen, Jun; Lu, Huiru; Zhou, Mengxue; Chai, Zhifang; Hu, Yi

    2017-12-01

    It is generally believed that gene-environment interaction may contribute to neurodegeneration. Of particular note is that iron overload may be one of the risk factors for neurodegeneration. However, the mechanisms underlying iron-associated neurotoxicity are not fully understood. Here we explored the effects of mechanistic target of rapamycin (mTOR) inhibition in iron-stressed human neuroblastoma cells. Two mTOR inhibitors, rapamycin and Torin 1, had similar effects in cells exposed to a relatively low concentration of iron. At a higher concentration of iron, Torin 1, instead of rapamycin, could further aggravate iron-induced cytotoxicity, and mitochondrial ROS levels were significantly higher in Torin 1-treated cells. These results suggest that mTOR inhibition may not be able to alleviate iron-induced neurotoxicity.

  12. Neuroprotective effects of electroacupuncture on hypoxic-ischemic encephalopathy in newborn rats association with increased expression of mTOR

    Directory of Open Access Journals (Sweden)

    Tao Xu

    2016-04-01

    Full Text Available In this study, we observed the therapeutic effects of acupuncture and investigated the underlying molecular mechanisms by constructed a hypoxic-ischemic encephalopathy (HIE animal model. In the electroacupuncture group, mTOR expression increased since 1d, and continued to rise till the 21st day. All of the differences were significantly (p<0.05 vs the model group. Meanwhile, mTOR expression was analyzed by Western blotting. There was statistical significance between the model group and the electroacupuncture group in the four time periods (p<0.05. The results provide evidence that electroacupuncture treatment protected cortical neurons against HIE-induced neuronal damage and degenerative changes in rats, which is in association with activation of mTOR both at the mRNA level and protein level. Therefore, electroacupuncture may become a potential therapeutic strategy for HIE of newborn.

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

    Science.gov (United States)

    Ma, Zhinan; Liu, Xiaoqiu; Li, Fujun; Wang, Yixong; Xu, Yang; Zhang, Mei; Zhang, Xiaoqian; Ying, Xiaoyan; Zhang, Xuesen

    2016-10-11

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

  14. Successful treatment with the mTOR inhibitor everolimus in a patient with Perivascular epithelioid cell tumor

    Directory of Open Access Journals (Sweden)

    Gennatas Constantine

    2012-09-01

    Full Text Available Abstract Perivascular epithelioid cell tumor (PEComa is an extremely rare neoplasm that appears to arise most commonly at visceral (especially gastrointestinal and uterine, retroperitoneal, and abdominopelvic sites. Malignant PEComas exist but are very rare. These tumors represent a family of mesenchymal neoplasms, mechanistically linked through activation of the mTOR signaling pathway. Metastatic PEComa is a rare form of sarcoma for which no effective therapy has been described previously and that has a uniformly fatal outcome. Although there is no known effective therapy, the molecular pathophysiology of aberrant mTOR signaling provides a scientific rationale to target this pathway therapeutically. The difficulty in determining optimal therapy, owing to the sparse literature available, led us to present this case. On this basis, we report a case of metastatic retroperitoneal PEComa treated with an oral mTOR inhibitor, with everolimus achieving significant clinical response.

  15. Topological susceptibility from the overlap

    DEFF Research Database (Denmark)

    Del Debbio, Luigi; Pica, Claudio

    2003-01-01

    The chiral symmetry at finite lattice spacing of Ginsparg-Wilson fermionic actions constrains the renormalization of the lattice operators; in particular, the topological susceptibility does not require any renormalization, when using a fermionic estimator to define the topological charge. Theref...

  16. A genetic screen identifies Tor as an interactor of VAPB in a Drosophila model of amyotrophic lateral sclerosis

    Directory of Open Access Journals (Sweden)

    Senthilkumar Deivasigamani

    2014-10-01

    Full Text Available Amyotrophic Lateral Sclerosis (ALS is a progressive neurodegenerative disorder characterized by selective death of motor neurons. In 5–10% of the familial cases, the disease is inherited because of mutations. One such mutation, P56S, was identified in human VAPB that behaves in a dominant negative manner, sequestering wild type protein into cytoplasmic inclusions. We have conducted a reverse genetic screen to identify interactors of Drosophila VAPB. We screened 2635 genes and identified 103 interactors, of which 45 were enhancers and 58 were suppressors of VAPB function. Interestingly, the screen identified known ALS loci – TBPH, alsin2 and SOD1. Also identified were genes involved in cellular energetics and homeostasis which were used to build a gene regulatory network of VAPB modifiers. One key modifier identified was Tor, whose knockdown reversed the large bouton phenotype associated with VAP(P58S expression in neurons. A similar reversal was seen by over-expressing Tuberous Sclerosis Complex (Tsc1,2 that negatively regulates TOR signaling as also by reduction of S6K activity. In comparison, the small bouton phenotype associated with VAP(wt expression was reversed with Tsc1 knock down as well as S6K-CA expression. Tor therefore interacts with both VAP(wt and VAP(P58S, but in a contrasting manner. Reversal of VAP(P58S bouton phenotypes in larvae fed with the TOR inhibitor Rapamycin suggests upregulation of TOR signaling in response to VAP(P58S expression. The VAPB network and further mechanistic understanding of interactions with key pathways, such as the TOR cassette, will pave the way for a better understanding of the mechanisms of onset and progression of motor neuron disease.

  17. Inflammatory stress increases hepatic CD36 translational efficiency via activation of the mTOR signalling pathway.

    Directory of Open Access Journals (Sweden)

    Chuan Wang

    Full Text Available Inflammatory stress is an independent risk factor for the development of non-alcoholic fatty liver disease (NAFLD. Although CD36 is known to facilitate long-chain fatty acid uptake and contributes to NAFLD progression, the mechanisms that link inflammatory stress to hepatic CD36 expression and steatosis remain unclear. As the mammalian target of rapamycin (mTOR signalling pathway is involved in CD36 translational activation, this study was undertaken to investigate whether inflammatory stress enhances hepatic CD36 expression via mTOR signalling pathway and the underlying mechanisms. To induce inflammatory stress, we used tumour necrosis factor alpha (TNF-α and interleukin-6 (IL-6 stimulation of the human hepatoblastoma HepG2 cells in vitro and casein injection in C57BL/6J mice in vivo. The data showed that inflammatory stress increased hepatic CD36 protein levels but had no effect on mRNA expression. A protein degradation assay revealed that CD36 protein stability was not different between HepG2 cells treated with or without TNF-α or IL-6. A polysomal analysis indicated that CD36 translational efficiency was significantly increased by inflammatory stress. Additionally, inflammatory stress enhanced the phosphorylation of mTOR and its downstream translational regulators including p70S6K, 4E-BP1 and eIF4E. Rapamycin, an mTOR-specific inhibitor, reduced the phosphorylation of mTOR signalling pathway and decreased the CD36 translational efficiency and protein level even under inflammatory stress resulting in the alleviation of inflammatory stress-induced hepatic lipid accumulation. This study demonstrates that the activation of the mTOR signalling pathway increases hepatic CD36 translational efficiency, resulting in increased CD36 protein expression under inflammatory stress.

  18. mTOR inhibition increases cell viability via autophagy induction during endoplasmic reticulum stress – An experimental and modeling study

    Directory of Open Access Journals (Sweden)

    Orsolya Kapuy

    2014-01-01

    Full Text Available Unfolded or misfolded proteins in the endoplasmic reticulum (ER trigger an adaptive ER stress response known as unfolded protein response (UPR. Depending on the severity of ER stress, either autophagy-controlled survival or apoptotic cell death can be induced. The molecular mechanisms by which UPR controls multiple fate decisions have started to emerge. One such molecular mechanism involves a master regulator of cell growth, mammalian target of rapamycin (mTOR, which paradoxically is shown to have pro-apoptotic role by mutually interacting with ER stress response. How the interconnections between UPR and mTOR influence the dynamics of autophagy and apoptosis activation is still unclear. Here we make an attempt to explore this problem by using experiments and mathematical modeling. The effect of perturbed mTOR activity in ER stressed cells was studied on autophagy and cell viability by using agents causing mTOR pathway inhibition (such as rapamycin or metyrapone. We observed that mTOR inhibition led to an increase in cell viability and was accompanied by an increase in autophagic activity. It was also shown that autophagy was activated under conditions of severe ER stress but that in the latter phase of stress it was inhibited at the time of apoptosis activation. Our mathematical model shows that both the activation threshold and temporal dynamics of autophagy and apoptosis inducers are sensitive to variation in mTOR activity. These results confirm that autophagy has cytoprotective role and is activated in mutually exclusive manner with respect to ER stress levels.

  19. FXR blocks the growth of liver cancer cells through inhibiting mTOR-s6K pathway

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiongfei, E-mail: xiongfeihuang@hotmail.com [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Key Laboratory of Ministry of Education for Gastrointestinal Cancer, Fujian Medical University, Fuzhou 350108, Fujian (China); Zeng, Yeting [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Wang, Xinrui [Department of Biochemistry and Molecular Biology, Fujian Medical University, Fuzhou 350108, Fujian (China); Ma, Xiaoxiao [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States); Li, Qianqian; Li, Ningbo; Su, Hongying [Department of Pathology and Institute of Oncology, Preclinical School, Fujian Medical University, Fuzhou 350108, Fujian (China); Huang, Wendong [Department of Diabetes Complications and Metabolism, Diabetes & Metabolism Research Institute, Beckman Research Institute, City of Hope, CA 91010 (United States)

    2016-05-27

    The nuclear receptor Farnesoid X Receptor (FXR) is likely a tumor suppressor in liver tissue but its molecular mechanism of suppression is not well understood. In this study, the gene expression profile of human liver cancer cells was investigated by microarray. Bioinformatics analysis of these data revealed that FXR might regulate the mTOR/S6K signaling pathway. This was confirmed by altering the expression level of FXR in liver cancer cells. Overexpression of FXR prevented the growth of cells and induced cell cycle arrest, which was enhanced by the mTOR/S6K inhibitor rapamycin. FXR upregulation also intensified the inhibition of cell growth by rapamycin. Downregulation of FXR produced the opposite effect. Finally, we found that ectopic expression of FXR in SK-Hep-1 xenografts inhibits tumor growth and reduces expression of the phosphorylated protein S6K. Taken together, our data provide the first evidence that FXR suppresses proliferation of human liver cancer cells via the inhibition of the mTOR/S6K signaling pathway. FXR expression can be used as a biomarker of personalized mTOR inhibitor treatment assessment for liver cancer patients. -- Highlights: •FXR inhibits the proliferation of liver cancer cells by prolonging G0/G1 phase. •Microarray results indicate that mTOR-S6k signaling is involved in cellular processes in which FXR plays an important role. •FXR blocks the growth of liver cancer cells via the inhibition of the mTOR/S6K signaling pathway in vitro and in vivo.

  20. Critical analysis of the potential for therapeutic targeting of mammalian target of rapamycin (mTOR in gastric cancer

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    Inokuchi M

    2014-04-01

    Full Text Available Mikito Inokuchi,1 Keiji Kato,1 Kazuyuki Kojima,2 Kenichi Sugihara1 1Department of Surgical Oncology, 2Department of Minimally Invasive Surgery, Tokyo Medical and Dental University, Tokyo, Japan Abstract: Multidisciplinary treatment including chemotherapy has become the global standard of care for patients with metastatic gastric cancer (mGC; nonetheless, survival remains poor. Although many molecular-targeted therapies have been developed for various cancers, only anti-HER2 treatment has produced promising results in patients with mGC. Mammalian target of rapamycin (mTOR plays a key role in cell proliferation, antiapoptosis, and metastasis in signaling pathways from the tyrosine kinase receptor, and its activation has been demonstrated in gastric cancer (GC cells. This review discusses the clinical relevance of mTOR in GC and examines its potential as a therapeutic target in patients with mGC. Preclinical studies in animal models suggest that suppression of the mTOR pathway inhibits the proliferation of GC cells and delays tumor progression. The mTOR inhibitor everolimus has been evaluated as second- or third-line treatment in clinical trials. Adverse events were well tolerated although the effectiveness of everolimus alone was limited. Everolimus is now being evaluated in combination with chemotherapy in Phase III clinical studies in this subgroup of patients. Two Phase III studies include exploratory biomarker research designed to evaluate the predictive value of the expression or mutation of molecules related to the Akt/mTOR signaling pathway. These biomarker studies may lead to the realization of targeted therapy for selected patients with mGC in the future. Keywords: gastric cancer, mTOR, everolimus

  1. Caloric restriction protects against electrical kindling of the amygdala by inhibiting the mTOR signaling pathway

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    Bryan Victor Phillips-Farfan

    2015-03-01

    Full Text Available Caloric restriction (CR has been shown to possess antiepileptic properties; however its mechanism of action is poorly understood. CR might inhibit the activity of the mammalian or mechanistic target of rapamycin (mTOR signaling cascade, which seems to participate crucially in the generation of epilepsy. Thus, we investigated the effect of CR on the mTOR pathway and whether CR modified epilepsy generation due to electrical amygdala kindling. The former was studied by analyzing the phosphorylation of adenosine monophosphate-activated protein kinase, protein kinase B and the ribosomal protein S6. The mTOR cascade is regulated by energy and by insulin levels, both of which may be changed by CR; thus we investigated if CR altered the levels of energy substrates in the blood or the level of insulin in plasma. Finally, we studied if CR modified the expression of genes that encode proteins participating in the mTOR pathway. CR increased the after-discharge threshold and tended to reduce the after-discharge duration, indicating an anti-convulsive action. CR diminished the phosphorylation of protein kinase B and ribosomal protein S6, suggesting an inhibition of the mTOR cascade. However, CR did not change glucose, β-hydroxybutyrate or insulin levels; thus the effects of CR were independent from them. Interestingly, CR also did not modify the expression of any investigated gene. The results suggest that the anti-epileptic effect of CR may be partly due to inhibition of the mTOR pathway.

  2. Inhibition of mTOR by Rapamycin Results in Auditory Hair Cell Damage and Decreased Spiral Ganglion Neuron Outgrowth and Neurite Formation In Vitro

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    Katharina Leitmeyer

    2015-01-01

    Full Text Available Rapamycin is an antifungal agent with immunosuppressive properties. Rapamycin inhibits the mammalian target of rapamycin (mTOR by blocking the mTOR complex 1 (mTORC1. mTOR is an atypical serine/threonine protein kinase, which controls cell growth, cell proliferation, and cell metabolism. However, less is known about the mTOR pathway in the inner ear. First, we evaluated whether or not the two mTOR complexes (mTORC1 and mTORC2, resp. are present in the mammalian cochlea. Next, tissue explants of 5-day-old rats were treated with increasing concentrations of rapamycin to explore the effects of rapamycin on auditory hair cells and spiral ganglion neurons. Auditory hair cell survival, spiral ganglion neuron number, length of neurites, and neuronal survival were analyzed in vitro. Our data indicates that both mTOR complexes are expressed in the mammalian cochlea. We observed that inhibition of mTOR by rapamycin results in a dose dependent damage of auditory hair cells. Moreover, spiral ganglion neurite number and length of neurites were significantly decreased in all concentrations used compared to control in a dose dependent manner. Our data indicate that the mTOR may play a role in the survival of hair cells and modulates spiral ganglion neuronal outgrowth and neurite formation.

  3. Phase I and pharmacokinetic study of capecitabine and the oral mTOR inhibitor everolimus in patients with advanced solid malignancies

    NARCIS (Netherlands)

    Deenen, Maarten J.; Klümpen, Heinz-Josef; Richel, Dick J.; Sparidans, Rolf W.; Weterman, Mariette J.; Beijnen, Jos H.; Schellens, Jan H. M.; Wilmink, Johanna W.

    2012-01-01

    Background Everolimus is an oral mTOR-inhibitor. Preclinical data show synergistic effects of mTOR inhibition in combination with 5-fluorouracil-based anticancer therapy. The combination of everolimus with capecitabine seems therefore an attractive new, orally available, treatment regimen. Patients

  4. The Neuroprotective Effect of Rapamycin as a Modulator of the mTOR-NF-κB Axis during Retinal Inflammation.

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    Tomohiro Okamoto

    Full Text Available The determination of the molecular mechanism underlying retinal pathogenesis and visual dysfunction during innate inflammation, and the treatment effect of rapamycin thereon.The endotoxin-induced uveitis and retinitis mouse model was established by injecting lipopolysaccharide. The mice were subsequently treated with rapamycin, a mammalian target of rapamycin (mTOR inhibitor. The rhodopsin mRNA and protein expression level in the retina and the photoreceptor outer segment (OS length in immunohistochemical stainings were measured, and visual function was recorded by electroretinography. Inflammatory cytokines, their related molecules, mTOR, and LC3 levels were measured by real-time PCR and/or immunoblotting. Leukocyte adhesion during inflammation was analyzed using concanavalin A lectin.The post-transcriptional reduction in the visual pigment of rod photoreceptor cells, rhodopsin, OS shortening, and rod photoreceptor cell dysfunction during inflammation were suppressed by rapamycin. Activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and induction of inflammatory cytokines, such as interleukin-6 (IL-6 and monocyte chemoattractant protein-1 (MCP-1, and the activation of the downstream signaling protein, signal transducer and activator of transcription 3 (STAT3, which reduces rhodopsin in the retina during inflammation, were attenuated by rapamycin. Increased leukocyte adhesion was also attenuated by rapamycin. Interestingly, although mTOR activation was observed after NF-κB activation, mTOR inhibition suppressed NF-κB activation at the early phase, indicating that the basal level of activated mTOR was sufficient to activate NF-κB in the retina. In addition, the inhibition of NF-κB suppressed mTOR activation, suggesting a positive feedback loop of mTOR and NF-κB during inflammation. The ratio of LC3II to LC3I, which reflects autophagy induction, was not changed by inflammation but was increased by rapamycin

  5. The Role of the New mTOR Complex, mTORC2, in Autism Spectrum Disorders

    Science.gov (United States)

    2015-10-01

    defined as “ autism spectrum disorders” (ASDs). ASD individuals exhibit common features such as impaired social interactions, language and...1 AWARD NUMBER: W81XWH-13-1-0380 TITLE: "The Role of the New mTOR Complex, mTORC2, in Autism Spectrum Disorders" PRINCIPAL INVESTIGATOR: Mauro...34The Role of the New mTOR Complex, mTORC2, in Autism Spectrum Disorders" 5a. CONTRACT NUMBER W81XWH-13-1-0380 5b. GRANT NUMBER 5c. PROGRAM

  6. Niclosamide inhibits lytic replication of Epstein-Barr virus by disrupting mTOR activation.

    Science.gov (United States)

    Huang, Lu; Yang, Mengtian; Yuan, Yan; Li, Xiaojuan; Kuang, Ersheng

    2017-02-01

    Infection with the oncogenic γ-herpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause several severe malignancies in humans. Inhibition of the lytic replication of EBV and KSHV eliminates the reservoir of persistent infection and transmission, consequently preventing the occurrence of diseases from the sources of infection. Antiviral drugs are limited in controlling these viral infectious diseases. Here, we demonstrate that niclosamide, an old anthelmintic drug, inhibits mTOR activation during EBV lytic replication. Consequently, niclosamide effectively suppresses EBV lytic gene expression, viral DNA lytic replication and virion production in EBV-infected lymphoma cells and epithelial cells. Niclosamide exhibits cytotoxicity toward lymphoma cells and induces irreversible cell cycle arrest in lytically EBV-infected cells. The ectopic overexpression of mTOR reverses the inhibition of niclosamide in EBV lytic replication. Similarly, niclosamide inhibits KSHV lytic replication. Thus, we conclude that niclosamide is a promising candidate for chemotherapy against the acute occurrence and transmission of infectious diseases of oncogenic γ-herpesviruses. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Hormesis does not make sense except in the light of TOR-driven aging

    Science.gov (United States)

    Blagosklonny, Mikhail V.

    2011-01-01

    Weak stresses (including weak oxidative stress, cytostatic agents, heat shock, hypoxia, calorie restriction) may extend lifespan. Known as hormesis, this is the most controversial notion in gerontology. For one, it is believed that aging is caused by accumulation of molecular damage. If so, hormetic stresses (by causing damage) must shorten lifespan. To solve the paradox, it was suggested that, by activating repair, hormetic stresses eventually decrease damage. Similarly, Baron Munchausen escaped from a swamp by pulling himself up by his own hair. Instead, I discuss that aging is not caused by accumulation of molecular damage. Although molecular damage accumulates, organisms do not live long enough to age from this accumulation. Instead, aging is driven by overactivated signal-transduction pathways including the TOR (Target of Rapamycin) pathway. A diverse group of hormetic conditions can be divided into two groups. “Hormesis A” inhibits the TOR pathway. “Hormesis B” increases aging-tolerance, defined as the ability to survive catastrophic complications of aging. Hormesis A includes calorie restriction, resveratrol, rapamycin, p53-inducing agents and, in part, physical exercise, heat shock and hypoxia. Hormesis B includes ischemic preconditioning and, in part, physical exercise, heat shock, hypoxia and medical interventions. PMID:22166724

  8. Traumatismo torácico bilateral: A propósito de 1 caso

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    Orlando Iglesias Pérez

    2002-12-01

    Full Text Available Se presenta un caso de traumatismo torácico bilateral extenso con tórax batiente, el cual fue tratado con inmovilización de las partes blandas torácicas, con alambres de Steinman pasados de manera caudocefálica, lo que provocó la estabilización de la caja y el mejoramiento rápido de las funciones ventilatorias y se logró la retirada oportuna de la intubación endotraqueal y la eliminación del proceso séptico asociado, lo que por la severidad y la utilización de un sistema de fijación externa, lo hace un caso anecdótico e interesante, y permite inducir la utilización de esta forma de tratamiento en casos similaresA case of extensive bilateral thoracic trauma with beating thorax was presented. The patient was treated with inmobilization of the thoracic soft parts by using Steinman wires that were passed through in a caudocephalic way, which caused the stabilization of the chest and the rapid improvement of the ventilatory functions. It made possible the opportune withdrawal of the endotracheal intubation and the elimination of the associated septic process. This is an anecdotic and interesting case due to its severity and to the utilization of an external fixation system. It allows to induce the application of this treatment in similar cases

  9. Cytoglobin inhibits migration through PI3K/AKT/mTOR pathway in fibroblast cells.

    Science.gov (United States)

    Demirci, Selami; Doğan, Ayşegül; Apdik, Hüseyin; Tuysuz, Emre Can; Gulluoglu, Sukru; Bayrak, Omer Faruk; Şahin, Fikrettin

    2018-01-01

    Cell proliferation and migration are crucial in many physiological processes including development, cancer, tissue repair, and wound healing. Cell migration is regulated by several signaling molecules. Identification of genes related to cell migration is required to understand molecular mechanism of non-healing chronic wounds which is a major concern in clinics. In the current study, the role of cytoglobin (CYGB) gene in fıbroblast cell migration and proliferation was described. L929 mouse fibroblast cells were transduced with lentiviral particles for CYGB and GFP, and analyzed for cell proliferation and migration ability. Fibroblast cells overexpressing CYGB displayed decreased cell proliferation, colony formation capacity, and cell migration. Phosphorylation levels of mTOR and two downstream effectors S6 and 4E-BP1 which take part in PI3K/AKT/mTOR signaling declined in CYGB-overexpressing cells. Microarray analysis indicated that CYGB overexpression leads to downregulation of cell proliferation, migration, and tumor growth associated genes in L929 cell line. This study demonstrated the role of CYGB in fibroblast cell motility and proliferation. CYGB could be a promising candidate for further studies as a potential target for diseases related to cell migration such as cancer and chronic wound treatment.

  10. A new mathematical approach for qualitative modeling of the insulin-TOR-MAPK network

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    H. Frederik Nijhout

    2013-09-01

    Full Text Available In this paper we develop a novel mathematical model of the insulin-TOR-MAPK signaling network that controls growth. Most data on the properties of the insulin and MAPK signaling networks are static and the responses to experimental interventions, such as knockouts, overexpression, and hormonal input are typically reported as scaled quantities. The modeling paradigm we develop here uses scaled variables and is ideally suited to simulate systems in which much of the available data are scaled. Our mathematical representation of signaling networks provides a way to reconcile theory and experiments, thus leading to a better understanding of the properties and function of these signaling networks. We test the performance of the model against a broad diversity of experimental data. The model correctly reproduces experimental insulin dose-response relationships. We study the interaction between insulin and MAPK signaling in the control of protein synthesis, and the interactions between amino acids, insulin and TOR signaling. We study the effects of variation in FOXO expression on protein synthesis and glucose transport capacity, and show that a FOXO knockout can partially rescue protein synthesis capacity of an insulin receptor knockout. We conclude that the modeling paradigm we develop provides a simple tool to investigate the qualitative properties of signaling networks.

  11. PI3K-AKT-mTOR inhibition in cancer immunotherapy, redux.

    Science.gov (United States)

    O'Donnell, Jake S; Massi, Daniela; Teng, Michele W L; Mandala, Mario

    2017-05-02

    Cancer therapies will increasingly be utilized in combination to treat advanced malignancies so as to increase their long-term efficacy in a greater proportion of patients. In particular, much attention has focused on developing targeted therapies that inhibit the PI3K-AKT-mTOR signaling network which is dysregulated in many cancer types. In addition, there is now a growing appreciation that targeting of these pathways can impact not only on cancer cells, but also host immunity. The clinical success of cancer immunotherapies targeting T-cell immune checkpoint receptors PD-1/PD-L1 has demonstrated the importance of immunoevasion as a hallmark of cancer. In this review, we discuss how PI3K-AKT-mTOR inhibitors target cancer cell biology, attenuate immune cell effector function and modulate the tumor microenvironment. We next discuss how the immunomodulatory potential of these inhibitors can be exploited through rational combinations with immunotherapies and targeted therapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Spatial Regulation of Root Growth: Placing the Plant TOR Pathway in a Developmental Perspective

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    Adam Barrada

    2015-08-01

    Full Text Available Plant cells contain specialized structures, such as a cell wall and a large vacuole, which play a major role in cell growth. Roots follow an organized pattern of development, making them the organs of choice for studying the spatio-temporal regulation of cell proliferation and growth in plants. During root growth, cells originate from the initials surrounding the quiescent center, proliferate in the division zone of the meristem, and then increase in length in the elongation zone, reaching their final size and differentiation stage in the mature zone. Phytohormones, especially auxins and cytokinins, control the dynamic balance between cell division and differentiation and therefore organ size. Plant growth is also regulated by metabolites and nutrients, such as the sugars produced by photosynthesis or nitrate assimilated from the soil. Recent literature has shown that the conserved eukaryotic TOR (target of rapamycin kinase pathway plays an important role in orchestrating plant growth. We will summarize how the regulation of cell proliferation and cell expansion by phytohormones are at the heart of root growth and then discuss recent data indicating that the TOR pathway integrates hormonal and nutritive signals to orchestrate root growth.

  13. mTOR signaling in proteostasis and its relevance to autism spectrum disorders

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    Judit Faus-Garriga

    2017-01-01

    Full Text Available Proteins are extremely labile cellular components, especially at physiological temperatures. The appropriate regulation of protein levels, or proteostasis, is essential for all cells. In the case of highly polarized cells like neurons, proteostasis is also crucial at synapses, where quick confined changes in protein composition occur to support synaptic activity and plasticity. The accurate regulation of those cellular processes controlling protein synthesis and degradation is necessary for proteostasis, and its deregulation has deleterious consequences in brain function. Alterations in those cellular mechanisms supporting synaptic protein homeostasis have been pinpointed in autism spectrum disorders such as tuberous sclerosis, neurofibromatosis 1, PTEN-related disorders, fragile X syndrome, MECP2 disorders and Angelman syndrome. Proteostasis alterations in these disorders share the alterations in mechanistic/mammalian target of rapamycin (mTOR signaling pathway, an intracellular pathway with key synaptic roles. The aim of the present review is to describe the recent literature on the major cellular mechanisms involved in proteostasis regulation in the synaptic context, and its association with mTOR signaling deregulations in various autism spectrum disorders. Altogether, the cellular and molecular mechanisms in synaptic proteostasis could be the foundation for novel shared therapeutic strategies that would take advantage of targeting common disorder mechanisms.

  14. Cyclin B Translation Depends on mTOR Activity after Fertilization in Sea Urchin Embryos

    Science.gov (United States)

    Boulben, Sandrine; Glippa, Virginie; Morales, Julia; Cormier, Patrick

    2016-01-01

    The cyclin B/CDK1 complex is a key regulator of mitotic entry. Using PP242, a specific ATP-competitive inhibitor of mTOR kinase, we provide evidence that the mTOR signalling pathway controls cyclin B mRNA translation following fertilization in Sphaerechinus granularis and Paracentrotus lividus. We show that PP242 inhibits the degradation of the cap-dependent translation repressor 4E-BP (eukaryotic initiation factor 4E-Binding Protein). PP242 inhibits global protein synthesis, delays cyclin B accumulation, cyclin B/CDK1 complex activation and consequently entry into the mitotic phase of the cell cycle triggered by fertilization. PP242 inhibits cyclin B mRNA recruitment into active polysomes triggered by fertilization. An amount of cyclin B mRNA present in active polysomes appears to be insensitive to PP242 treatment. Taken together, our results suggest that, following sea urchin egg fertilization, cyclin B mRNA translation is controlled by two independent mechanisms: a PP242-sensitive and an additional PP242-insentitive mechanism. PMID:26962866

  15. mTOR signaling disruption from myeloid-derived suppressive cells protects against immune-mediated hepatic injury through the HIF1α-dependent glycolytic pathway.

    Science.gov (United States)

    Chen, Xi; Zhang, Zhengguo; Bi, Yujing; Fu, Zan; Gong, Pingsheng; Li, Yan; Yu, Qing; Jia, Anna; Wang, Jian; Xue, Lixiang; Yang, Hui; Liu, Guangwei

    2016-12-01

    The mechanistic target of rapamycin (mTOR) pathway integrates diverse environmental inputs, including immune signals and metabolic cues, to direct innate and adaptive immune responses. Myeloid-derived suppressive cells (MDSCs) are a heterogeneous cell population that plays a crucial regulatory effect in immune-related diseases. However, whether mTOR signaling affects the functions of MDSCs remains largely unexplored. Here, we show that mTOR signaling is a pivotal, negative determinant of MDSC function in immune-mediated hepatic injury (IMH) diseases. In the context of IMH, the blocking of mTOR with rapamycin or mTOR-deficient CD11b+Gr1+ MDSCs mediates the protection against IMH; mTOR with rapamycin and mTOR-deficient CD11b+Gr1+ MDSCs are suppressive immune modulators that result in less IFN-γ-producing TH1 cells and more Foxp3+ Tregs Mechanistically, mTOR activity down-regulation in MDSCs induced iNOS expressions and NO productions. Pharmacologic inhibitions of iNOS completely eliminate MDSC-suppressive function and lose their inducible effects on T cell differentiation. Importantly, HIF1α-dependent glycolytic activity is responsible for mTOR-deficient, increased MDSC functional changes in IMH inflammation. Thus, these data demonstrate that mTOR acts as a fundamental "rheostat" in MDSCs to link immunologic signals to glycolytic pathways and functional fitness and highlights a central role of metabolic programming of MDSC-suppressive activity in protecting against immune hepatic injuries. © Society for Leukocyte Biology.

  16. Reducing Susceptibility to Courtesy Stigma.

    Science.gov (United States)

    Bachleda, Catherine L; El Menzhi, Leila

    2017-04-19

    In light of the chronic shortage of health professionals willing to care for HIV/AIDS patients, and rising epidemics in many Muslim countries, this qualitative study examined susceptibility and resistance to courtesy stigma as experienced by nurses, doctors, and social workers in Morocco. Forty-nine in-depth interviews provided rich insights into the process of courtesy stigma and how it is managed, within the context of interactions with Islam, interactions within the workplace (patients, other health professionals), and interactions outside the workplace (the general public, friends, and family). Theoretically, the findings extend understanding of courtesy stigma and the dirty work literature. The findings also offer practical suggestions for the development of culturally appropriate strategies to reduce susceptibility to courtesy stigmatization. This study represents the first to explore courtesy stigma as a process experienced by health professionals providing HIV/AIDS care in an Islamic country.

  17. Antimycotics susceptibility testing of dermatophytes

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    Arsić-Arsenijević Valentina

    2010-01-01

    Full Text Available Dermatophytes are moulds that produce infections of the skin, hair and nails of humans and animals. The most common forms among these infections are onychomycosis and tinea pedis affecting 20% of world population. These infections are usually chronic. The treatment of dermatophytoses tends to be prolonged partly because available treatments are not very effective. Antifungal drug consumption and public health expenditure are high worldwide, as well as in Serbia. For adequate therapy, it is necessary to prove infection by isolation of dermatophytes and to test the antifungal susceptibility of isolates. Susceptibility testing is important for the resistance monitoring, epidemiological research and to compare in vitro activities of new antifungal agents. The diffusion and dilution methods of susceptibility tests are used, and technical issues of importance for the proper performance and interpretation of test results are published in the document E.DEF 9.1 (EUCAST and M38-A2 (CLSI. The aim of our paper is to promptly inform the public about technical achievements in this area, as well as the new organization of laboratory for medical mycology in our country. The formation of laboratory networks coordinated by the National Reference Laboratory for the cause of mycosis need to enable interlaboratory studies and further standardization of methods for antifungal susceptibility testing of dermatophytes, reproducibility of tests and clinical correlation monitoring (MIK values and clinical outcome of dermatophytosis. The importance of the new organization is expected efficient improvement in the dermatophytosis therapy at home, better quality of patient's life and the reduction of the cost of treatment.

  18. Antibiotic susceptibility of Atopobium vaginae

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    Verschraegen Gerda

    2006-03-01

    Full Text Available Abstract Background Previous studies have indicated that a recently described anaerobic bacterium, Atopobium vaginae is associated with bacterial vaginosis (BV. Thus far the four isolates of this fastidious micro-organism were found to be highly resistant to metronidazole and susceptible for clindamycin, two antibiotics preferred for the treatment of BV. Methods Nine strains of Atopobium vaginae, four strains of Gardnerella vaginalis, two strains of Lactobacillus iners and one strain each of Bifidobacterium breve, B. longum, L. crispatus, L. gasseri and L. jensenii were tested against 15 antimicrobial agents using the Etest. Results All nine strains of A. vaginae were highly resistant to nalidixic acid and colistin while being inhibited by low concentrations of clindamycin (range: G. vaginalis strains were also susceptible for clindamycin ( 256 μg/ml but susceptible to clindamycin (0.023 – 0.125 μg/ml. Conclusion Clindamycin has higher activity against G. vaginalis and A. vaginae than metronidazole, but not all A. vaginae isolates are metronidazole resistant, as seemed to be a straightforward conclusion from previous studies on a more limited number of strains.

  19. DEPTOR-related mTOR suppression is involved in metformin's anti-cancer action in human liver cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Obara, Akio; Fujita, Yoshihito; Abudukadier, Abulizi; Fukushima, Toru; Oguri, Yasuo; Ogura, Masahito; Harashima, Shin-ichi; Hosokawa, Masaya; Inagaki, Nobuya, E-mail: inagaki@metab.kuhp.kyoto-u.ac.jp

    2015-05-15

    Metformin, one of the most commonly used drugs for patients with type 2 diabetes, recently has received much attention regarding its anti-cancer action. It is thought that the suppression of mTOR signaling is involved in metformin's anti-cancer action. Although liver cancer is one of the most responsive types of cancer for reduction of incidence by metformin, the molecular mechanism of the suppression of mTOR in liver remains unknown. In this study, we investigated the mechanism of the suppressing effect of metformin on mTOR signaling and cell proliferation using human liver cancer cells. Metformin suppressed phosphorylation of p70-S6 kinase, and ribosome protein S6, downstream targets of mTOR, and suppressed cell proliferation. We found that DEPTOR, an endogenous substrate of mTOR suppression, is involved in the suppressing effect of metformin on mTOR signaling and cell proliferation in human liver cancer cells. Metformin increases the protein levels of DEPTOR, intensifies binding to mTOR, and exerts a suppressing effect on mTOR signaling. This increasing effect of DEPTOR by metformin is regulated by the proteasome degradation system; the suppressing effect of metformin on mTOR signaling and cell proliferation is in a DEPTOR-dependent manner. Furthermore, metformin exerts a suppressing effect on proteasome activity, DEPTOR-related mTOR signaling, and cell proliferation in an AMPK-dependent manner. We conclude that DEPTOR-related mTOR suppression is involved in metformin's anti-cancer action in liver, and could be a novel target for anti-cancer therapy. - Highlights: • We elucidated a novel pathway of metformin's anti-cancer action in HCC cells. • DEPTOR is involved in the suppressing effect of metformin on mTOR signaling. • Metformin increases DEPTOR protein levels via suppression of proteasome activity. • DEPTOR-related mTOR suppression is involved in metformin's anti-cancer action.

  20. Seizure-dependent mTOR activation in 5-HT neurons promotes autism-like behaviors in mice.

    Science.gov (United States)

    McMahon, John J; Yu, Wilson; Yang, Jun; Feng, Haihua; Helm, Meghan; McMahon, Elizabeth; Zhu, Xinjun; Shin, Damian; Huang, Yunfei

    2015-01-01

    Epilepsy and autism spectrum disorder (ASD) are common comorbidities of one another. Despite the prevalent correlation between the two disorders, few studies have been able to elucidate a mechanistic link. We demonstrate that forebrain specific Tsc1 deletion in mice causes epilepsy and autism-like behaviors, concomitant with disruption of 5-HT neurotransmission. We find that epileptiform activity propagates to the raphe nuclei, resulting in seizure-dependent hyperactivation of mTOR in 5-HT neurons. To dissect whether mTOR hyperactivity in 5-HT neurons alone was sufficient to recapitulate an autism-like phenotype we utilized Tsc1flox/flox;Slc6a4-cre mice, in which mTOR is restrictively hyperactivated in 5-HT neurons. Tsc1flox/flox;Slc6a4-cre mice displayed alterations of the 5-HT system and autism-like behaviors, without causing epilepsy. Rapamycin treatment in these mice was sufficient to rescue the phenotype. We conclude that the spread of seizure activity to the brainstem is capable of promoting hyperactivation of mTOR in the raphe nuclei, which in turn promotes autism-like behaviors. Thus our study provides a novel mechanism describing how epilepsy can contribute to the development of autism-like behaviors, suggesting new therapeutic strategies for autism. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Chronic overload induced hypertrophy is associated with age-related muscle mass loss and diminished mTOR signaling

    Science.gov (United States)

    The purpose of this study was to assess activation of the mTOR signaling pathway in young and aging rats in response to chronic muscle overload. Young (6 mo; n = 16) and older (30 mo; n = 23) male rats (F344xBN) were subjected to 4 weeks of bilateral surgical ablation (SA) of two-thirds of the gastr...

  2. Effects of chronic overload on muscle hypertrophy and mTOR signaling in adult and aged rats

    Science.gov (United States)

    We examined the effect of 28 days of overload on mammalian target of rapamycin (mTOR) and extracellular signal-regulated kinase (ERK) signaling in young adult (Y; 6 mo old) and aged (O; 30 mo old) Fischer 344 x Brown Norway rats subjected to bilateral synergist ablation (SA) of two-thirds of the gas...

  3. Estradiol-Induced Object Recognition Memory Consolidation Is Dependent on Activation of mTOR Signaling in the Dorsal Hippocampus

    Science.gov (United States)

    Fortress, Ashley M.; Fan, Lu; Orr, Patrick T.; Zhao, Zaorui; Frick, Karyn M.

    2013-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway is an important regulator of protein synthesis and is essential for various forms of hippocampal memory. Here, we asked whether the enhancement of object recognition memory consolidation produced by dorsal hippocampal infusion of 17[Beta]-estradiol (E[subscript 2]) is dependent on mTOR…

  4. The actions of exogenous leucine on mTOR signalling and amino acid transporters in human myotubes

    Directory of Open Access Journals (Sweden)

    Cameron-Smith David

    2011-06-01

    Full Text Available Abstract Background The branched-chain amino acid (BCAA leucine has been identified to be a key regulator of skeletal muscle anabolism. Activation of anabolic signalling occurs via the mammalian target of rapamycin (mTOR through an undefined mechanism. System A and L solute carriers transport essential amino acids across plasma membranes; however it remains unknown whether an exogenous supply of leucine regulates their gene expression. The aim of the present study was to investigate the effects of acute and chronic leucine stimulation of anabolic signalling and specific amino acid transporters, using cultured primary human skeletal muscle cells. Results Human myotubes were treated with leucine, insulin or co-treated with leucine and insulin for 30 min, 3 h or 24 h. Activation of mTOR signalling kinases were examined, together with putative nutrient sensor human vacuolar protein sorting 34 (hVps34 and gene expression of selected amino acid transporters. Phosphorylation of mTOR and p70S6K was transiently increased following leucine exposure, independently to insulin. hVps34 protein expression was also significantly increased. However, genes encoding amino acid transporters were differentially regulated by insulin and not leucine. Conclusions mTOR signalling is transiently activated by leucine within human myotubes independently of insulin stimulation. While this occurred in the absence of changes in gene expression of amino acid transporters, protein expression of hVps34 increased.

  5. Therapeutic effects of antibiotic drug mefloquine against cervical cancer through impairing mitochondrial function and inhibiting mTOR pathway.

    Science.gov (United States)

    Li, Hui; Jiao, Shun; Li, Xin; Banu, Hasina; Hamal, Shreejana; Wang, Xianrong

    2017-01-01

    Targeting mitochondria is an attractive strategy for cancer therapy due to the essential roles of mitochondria in cancer cell energy metabolism. In this study, we show that mefloquine, an antibiotic drug, effectively targets cervical cancer cells through impairing mitochondrial function. Mefloquine dose-dependently induces apoptosis and inhibits proliferation and anchorage-independent colony formation of multiple cervical cancer cell lines. Mefloquine alone inhibits cervical tumor growth in vivo and its combination with paclitaxel is synergistic in inhibiting tumor growth. Mechanistically, mefloquine inhibits mitochondrial function via inhibiting mitochondrial respiration, decreasing membrane potential, increasing ROS generation, and decreasing ATP level. We further show that mefloquine suppresses activation of mTOR signaling pathway in HeLa cells. However, the inhibitory effects of mefloquine on survival, colony formation, and ATP are abolished in mitochondrial respiration-deficient HeLa ρ0 cells, demonstrating that mefloquine acts on cervical cancer cells via targeting mitochondrial respiration. Inhibition of mTOR signaling pathway by mefloquine was also reversed in HeLa ρ0 cells, suggesting deactivation of mTOR pathway as a consequence of mitochondria function disruption. Our work suggests that mefloquine is a potential candidate for cervical cancer treatment. Our work also highlights the therapeutic value of anti-mitochondria and establishes the association of mitochondrial function and the activation of mTOR signaling pathway in cervical cancer cells.

  6. The psychic term "ētor": its nature and relation to person in Homer and the Homeric Hymns.

    Science.gov (United States)

    Sullivan, S D

    1996-01-01

    Discusses the use in early Greek epic poetry of "ētor", one of the three terms for "heart". This word serves frequently as a seat of emotion in individuals, especially of joy, anger and grief. It can also be involved in thought, particularly in emotional situations.

  7. Characterization of the porcine TOR1A gene: The first step towards generation of a pig model for dystonia

    DEFF Research Database (Denmark)

    Henriksen, Carina; Madsen, Lone Bruhn; Bendixen, Christian

    2009-01-01

    by reverse transcriptase polymerase chain reaction (RT-PCR), using oligonucleotide primers derived from in silico sequences. The porcine TOR1A cDNAs both encode a protein of 333 amino acids which shows a very high similarity to human (92%) TorsinA. Protein structure comparison of human and porcine Torsin...

  8. Critical analysis of graft loss and death in kidney transplant recipients treated with mTOR inhibitors

    Directory of Open Access Journals (Sweden)

    Luis Gustavo Modelli de Andrade

    Full Text Available Abstract Registry studies and systematic reviews have shown higher risk for mortality and graft loss in patients in use of mTOR inhibitors (mTORi compared to calcineurin-based (CNI immunosuppressive regimens. The majority of these studies pooled data from early trials using different strategies such as "de novo" combination of the high dose mTOR inhibitors with standard dose of CNI or high dose mTORi combined with mycophenolate. The large heterogeneity of these initial exploratory studies, many of them no longer in use, turns difficult any comparison with a well-defined standard of care regimen. The new strategies using concentration controlled reduced exposure of mTORi and CNI or early conversion from CNI to mTORi use have shown comparable patient and graft survival. Nevertheless, considering the central role of mTOR in health and disease states, more research is necessary to mitigate the adverse events and to explore further the potential beneficial effects of mTOR inhibitors.

  9. Reversion of Hormone Treatment Resistance with the Addition of an mTOR Inhibitor in Endometrial Stromal Sarcoma

    Directory of Open Access Journals (Sweden)

    J. Martin-Liberal

    2014-01-01

    Full Text Available Background. Endometrial stromal sarcomas (ESS are a subtype of gynaecological sarcomas characterized by the overexpression of hormone receptors. Hormone treatment is widely used in ESS but primary or acquired resistance is common. The mammalian target of rapamycin (mTOR pathway has been suggested to play a key role in the mechanisms of hormone resistance. Recent studies in breast and prostate cancer demonstrate that this resistance can be reversed with the addition of an mTOR inhibitor. This phenomenon has never been reported in ESS. Methods. We report the outcome of one patient with pretreated, progressing low grade metastatic ESS treated with medroxyprogesterone acetate in combination with the mTOR inhibitor sirolimus. Results. Partial response was achieved following the addition of sirolimus to the hormone treatment. Response has been maintained for more than 2 years with minimal toxicity and treatment is ongoing. Conclusion. This case suggests that the resistance to the hormone manipulation in ESS can be reversed by the addition of an mTOR pathway inhibitor. This observation is highly encouraging and deserves further investigation.

  10. Recent Advances and Challenges of mTOR Inhibitors Use in the Treatment of Patients with Tuberous Sclerosis Complex

    Directory of Open Access Journals (Sweden)

    Filipe Palavra

    2017-01-01

    Full Text Available Tuberous sclerosis complex (TSC is a genetic condition characterized by the presence of benign, noninvasive, and tumor-like lesions called hamartomas that can affect multiple organ systems and are responsible for the clinical features of the disease. In the majority of cases, TSC results from mutations in the TSC1 and TSC2 genes, leading to the overactivation of the mammalian target of rapamycin (mTOR signalling pathway, which controls several cell functions, including cell growth, proliferation, and survival. The establishment of a connection between TSC and mTOR led to the clinical use of drugs known as mTOR inhibitors (like rapamycin, also known as sirolimus and everolimus, which are becoming an increasingly interesting tool in the management of TSC-associated features, such as subependymal giant cell astrocytomas, renal angiomyolipomas, and also epilepsy. However, the intrinsic characteristics of these drugs and their systemic effects in such a heterogeneous condition pose many challenges in clinical practice, so that some questions remain unanswered. This article provides an overview of the pharmacological aspects of mTOR inhibitors about the clinical trials leading to their approval in TSC-related conditions and exposes current challenges and future directions associated with this promising therapeutic line.

  11. Measurements of temperature dependence of 'localized susceptibility'

    CERN Document Server

    Shiozawa, H; Ishii, H; Takayama, Y; Obu, K; Muro, T; Saitoh, Y; Matsuda, T D; Sugawara, H; Sato, H

    2003-01-01

    The magnetic susceptibility of some rare-earth compounds is estimated by measuring magnetic circular dichroism (MCD) of rare-earth 3d-4f absorption spectra. The temperature dependence of the magnetic susceptibility obtained by the MCD measurement is remarkably different from the bulk susceptibility in most samples, which is attributed to the strong site selectivity of the core MCD measurement.

  12. Estradiol inhibits osteoblast apoptosis via promotion of autophagy through the ER-ERK-mTOR pathway.

    Science.gov (United States)

    Yang, Yue-Hua; Chen, Ke; Li, Bo; Chen, Jiang-Wei; Zheng, Xin-Feng; Wang, Yu-Ren; Jiang, Sheng-Dan; Jiang, Lei-Sheng

    2013-11-01

    activation of Caspase-3 and induced autophagy through inhibition of phospho-mammalian target of rapamycin (p-mTOR). Both 3-methyladenine (3MA) and U0126 led to increase of apoptosis in osteoblasts with serum deprivation. Estradiol failed to over-ride the inhibitory effect of 3MA on phosphorylation of AKT but directly led to dephosphorylation of mTOR and upregulation of LC3 protein expression. However, the estradiol-enhanced LC3 protein expression was significantly suppressed by U0126 through inhibition of phosphorylation of extracellular signal-regulated kinase (ERK). Estradiol rescued osteoblast apoptosis via promotion of autophagy through the ER-ERK-mTOR pathway.

  13. [Effects of mTOR Inhibitor Rapamycin on Burkitt's Lymphoma Cells].

    Science.gov (United States)

    Zhou, Lun-Huan; Zhu, Xiong-Peng; Xiao, Hui-Fang; Xin, Peng-Liang; Li, Chun-Tuan

    2017-10-01

    To explore the effects of mTOR inhibitor rapamycin on proliferation, cell cycle and apoptosis of Burkitt's lymphoma cell line Raji and CA46 cells and its mechanism, so as to provide the experimental evidence for a therapeutic target of Burkitt's lymphoma. 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay was performed to assess the inhibitory effect of rapamycin on proliferation of Burkitt's lymphoma cell line Raji and CA46 cells. The cell cycle distribution of Raji and CA46 cells was analyzed by flow cytometry with propidium iodide(PI) single staining. The cell apoptosis of Raji and CA46 cells was analyzed by flow cytometry with FITC Annexin V+PI double staining. The expressions of RPS6, p-RPS6, survivin and caspase-3 proteins were detected by Western blot after treating with rapamycin. Rapamycin markedly inhibited the proliferation of both Raji and CA46 cells in a time- and concentration-dependent manners, showing good biological activity, the cell proliferation inhibition rate reached about 20% after treatment with 1 nmol/L rapamycin. After treatment with different concentrations of rapamycin for 24 and 48 hours, the proportion of both cells in G1/G0 phase in the treated groups was significantly increased in a time- and concentration-dependent manners in comparison with the solvent control group. With regard to the cells in S and G2/M phase, the decreased population was accompanied by the increase of G1/G0 phase cells. After treatment with 100 nmol/L rapamycin for 48 hours, both Raji and CA46 cells demonstrated an apparent apoptosis,especially late apoptosis by flow cytometry with Annexin V+PI staining. After treatment with rapamycin, the expression of p-RPS6 and survivin of Raji and CA46 cells was obviously down-regulated, the expression of caspase-3 was obviously up-regulated in a time- and dose-dependent manners. However, rapamycin did not obviously affect the expression of RPS6. The rapamycin can effectively inhibit cell proliferation

  14. Ecografia na patologia torácica Ultrasound in chest disease

    Directory of Open Access Journals (Sweden)

    António Bugalho

    2010-08-01

    Full Text Available Nos últimos anos a ecografia torácica tem vindo a ser reconhecida como um instrumento de extrema importância para os pneumologistas. Actualmente, os equipamentos são práticos, portáteis, de fácil utilização e fidedignos, o que os torna apropriados para utilização no diagnóstico e orientação de procedimentos terapêuticos. Na avaliação de derrame pleural e condução de toracentese são necessárias competências técnicas básicas em ultra-sonografia. Procedimentos mais complexos devem ser realizados perante treino específico e incluem a colocação de dreno torácico e identificação com eventual biopsia de lesões torácicas. Os autores procuram abordar, de um ponto de vista prático, a técnica e os recentes avanços alcançados neste campo. São apresentados alguns casos clínicos no sentido de ilustrar e guiar aqueles que desejam iniciar a realização de ecografia do tórax.In the past few years transthoracic ultrasound has been recognized as an important tool for chest physicians. At present, ultrasound devices are practical, portable, easy to use and reliable, which makes them suited for diagnostic investigations as well as for therapeutic procedures guidance. Basic ultrasound technical expertise is required to assess pleural effusions and perform ultrasound-guided thoracentesis. More complex procedures can be done with specific training and include assistance to chest drain insertion and identification with potential biopsy of thoracic lesions. The authors aim to review, in a practical approach, the technique and recent developments in this field. Clinical cases are presented in order to illustrate and guide the beginner in chest ultrasound.

  15. PENGARUH Implantasi HCG PADA PERKEMBANGAN TELUR, Pematangan Akhir Gonad, dan Pemijahan Ikan Tor soro

    Directory of Open Access Journals (Sweden)

    Jojo Subagja

    2016-11-01

    Full Text Available Penelitian tentang implantasi hormon Human Chorionic Gonadotropin (HCG dengan tujuan untuk mengetahui pengaruhnya terhadap perkembangan pematangan akhir gonad dan pemijahan ikan Tor soro telah dilakukan di Instalasi Riset Plasma Nutfah Perikanan Budidaya Air Tawar, Cijeruk-Bogor. Perlakuan dosis hormon yang diimplantasikan adalah: 300; 400; 500 IU.Kg-1 bobot tubuh dan kontrol (tanpa hormon. Hasil penelitian menunjukkan ada perbedaan nyata antara perlakuan pada pengamatan ke 25 dan 50 hari setelah implantasi, yaitu pemberian pelet hormon dengan kadar 500 IU.kg-1 bobot tubuh, menghasilkan perkembangan diameter oosit paling besar dengan rataan diameter oosit 3,07 ± 0,31 mm dibandingkan dengan perlakuan lainnya, diikuti perlakuan  kontrol, 300 IU.kg-1 bobot tubuh dan 400 IU.kg-1 bobot tubuh, dengan nilai rataan berturut-turut 2,11 ± 0,53 mm; 1,97 ± 0,55 mm; dan 0,87 ± 0,50 mm. Keberhasilan pemijahan pada dosis implan 500 IU. kg-1 bobot tubuh mencapai 100% dengan kisaran waktu laten antara 25 dan 27 jam dengan suhu inkubasi 22°C—24°C, serta larva normal berkembang mencapai 90,19%. Study aimed to identify the effect of Human Chorionic Gonadotropin hormone implantation on gonadal development, final maturation, and spawning of Tor soro was conducted at Research Instalation of Germ Plasm Cijeruk-Bogor. Experimental dosage of hormone treated were 300, 400, 500 IU kg-1 body weight and control (without hormonal treatment. The result showed a significant difference between each treatment observed at the 25th and 50 th day after implantation. Hormon pellet at dosage 500 IU kg-1 body weight produced the biggest oocytes with average diameter 3.07 ± 0.31 mm, and followed by control, 300 IU treatment and 400 IU treatment with average diameter were 2.11 ± 0.53 mm, 1.97 ± 0.55 mm and 0.87 ± 0.50 mm, respectively. Succesful spawning rate of Tor soro treated hormone pellet of 500 IU kg-1 body weight reached of 100% at latentcy time of 25—27 hour

  16. Relato de caso: anestesia em paciente portador de distrofia torácica asfixiante: Síndrome de Jeune

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    Deise Saletti

    2012-06-01

    Full Text Available JUSTIFICATIVA E OBJETIVOS: Síndrome de Jeune, ou Distrofia Torácica Asfixiante, é uma doença autossômica recessiva. Esta síndrome é caracterizada por uma displasia óssea com variadas anormalidades: torácica, pancreática, cardíaca, hepática, renal e da retina. A idade em que o quadro clínico dos pacientes se apresenta está correlacionada com a gravidade da doença. Esses pacientes apresentam policondrodistrofia com costelas largas, curtas, horizontais e junções costocondrais irregulares levando a uma caixa torácica rígida e reduzida com grau de injúria respiratória variado. RELATO DO CASO: Paciente do sexo masculino, 4 meses, 7 kg, portador de Distrofia Torácica Asfixiante. Apresentava-se intubado e com caixa torácica reduzida. Ecocardiograma: hipertensão pulmonar leve. Tomografia de tórax: hipoplasia pulmonar. Submetido à toracoplastia bilateral e toracotomia sob anestesia geral. Manutenção da anestesia: infusão contínua de sufentanil e sevoflurano. Parâmetros ventilatórios: ventilação mecânica ciclada à pressão. Com a abertura do tórax, houve melhora dos parâmetros ventilatórios e, após o posicionamento da prótese torácica, observou-se limitação ventilatória. Decidiu-se pela diminuição da prótese torácica com consequente melhora da ventilação. CONCLUSÕES: É imprescindível o diagnóstico de todas as anormalidades presentes para o correto manejo anestésico. Foi necessária observação para adequar ventilação pré- e pós-toracotomia/toracoplastia e para manter o paciente hemodinamicamente estável. A forma mais adequada para ventilação mecânica é a ciclada à pressão para vencer a barreira mecânica. No intraoperatório, é desejável manter o pico de pressão inspiratória o mais baixo possível para minimizar o risco de barotrauma, de impedimento do retorno venoso e diminuição do débito cardíaco.

  17. Quality of sperm from cryopreserved semen of Tor soro in Dimethylsulfoxide and Glycerol 5, 10 and 15%

    Directory of Open Access Journals (Sweden)

    M. Zairin Junior

    2007-07-01

    Full Text Available Attempt to produce a lot number of Tor soro is difficult if only obtained by natural spawning since they often get mature in dissimilar time. Stock of sperm kept in enough number for fertilization in anytime is needed to overcome the problem.  Cryopreservation of semen is one of sperm cryopreservation methods using liquid nitrogen (-196oC to quickly freeze the sperm. Several cryoprotectants can be utilized in cryopreservation.  In this study, quality by means of motility of cryopreserved sperm using dimethylsulfoxide or glycerol as cryoprotectant in the dose of 5, 10 and 15% were analyzed. The result of study show that percentage of sperm motile after cryopreservation using dimethylsulfoxide and glycerol was similar ranged from 76.7 to 83.3%.  Therefore, both cryoprotectant used in this study could be employed for cryopreservation of Tor soro sperm. Keywords: cryopreservation, dimethylsulfoxide, glycerol, sperm, Tor soro   ABSTRAK Upaya produksi ikan batak (Tor soro dalam jumlah besar relatif sulit jika hanya mengandalkan hasil pemijahan secara alami karena kematangan gonad antara ikan jantan dan betina sering tidak bersamaan. Untuk mengatasinya diperlukan stok sperma yang disimpan dalam jumlah yang cukup banyak untuk pembuahan yang dapat dipakai setiap saat. Kriopreservasi semen merupakan salah satu cara penyimpanan sperma yang menggunakan larutan nitrogen cair (-196°C untuk membekukan sperma secara cepat. Beberapa jenis protektan dapat digunakan dalam pembekuan sperma. Pada penelitian ini, dilakukan analisis kualitas dalam arti motilitas sperma hasil kriopreservasi menggunakan dimetilsulfoksida dan gliserol sebagai krioprotektan dengan dosis 5, 10 dan 15%.  Hasil penelitian menunjukkan bahwa persentase sperma motil setelah dilakukan kriopreservasi adalah sama, berkisar antara 76,7% hingga 83,35%.  Dengan demikian, kedua jenis krioprotektan yang digunakan dalam penelitian ini bisa dipakai dalam kriopreservasi sperma ikan batak. Kata

  18. PTEN and rapamycin inhibiting the growth of K562 cells through regulating mTOR signaling pathway

    Directory of Open Access Journals (Sweden)

    Chen Hao

    2008-12-01

    Full Text Available Abstract Objective To investigate, in vitro, the regulatory effects of tumor-suppressing gene PTEN on mTOR (mammalian target of rapamycin signaling pathway, the effects of transfected PTEN and rapamycin on the growth inhibition, and apoptosis induction for human leukemia cell line K562 cells. Methods K562 cells were transfected with recombined adenovirus-PTEN vector containing green fluorescent protein (Ad-PTEN-GFP, followed by the treatment of the cells with or without rapamycin. The proliferation inhibition rate and apoptotic rate of these transfected and/or rapamycin treated K562 cells were measured by MTT assay and flow cytometry (FCM, the expression levels of PTEN-, mTOR-, cyclinD1- and P27kip1- mRNA were measured by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR, the protein expression levels of PTEN, Akt, p-Akt were detected by western blotting. Results The proliferation of K562 cells was inhibited by PTEN gene transfection with/without the treatment of rapamycin. The expression levels of PTEN- and P27kip1- mRNA were up-regulated, and the mTOR- and cyclinD1- mRNA were down-regulated in K562 cells after the cells transfected with wild type PTEN gene and treated with rapamycin. Conclusion PTEN and rapamycin inhibited mTOR expression by acting as an upstream regulator of mTOR. Low dose rapamycin in combination with over-expressed PTEN might have synergistic effects on inhibiting the proliferation and promoting apoptosis of K562 cells.

  19. Role of the Phosphorylation of mTOR in the Differentiation of AML Cells Triggered with CD44 Antigen

    KAUST Repository

    Darwish, Manar M

    2013-05-01

    Acute myeloid leukemia (AML) is a hematological disorder characterized by blockage of differentiation of myeloblasts. To date, the main therapy for AML is chemotherapy. Yet, studies are seeking a better treatment to enhance the survival rate of patients and minimize the relapsing of the disease. Since the major problem in these cells is that they are arrested in cellular differentiation, drugs that could induce their differentiation have proven to be efficient and of major interest for AML therapy. CD44 triggering appeared as a promising target for AML therapy as it has been shown that specific monoclonal antibodies, such as A3D8 and H90, reversed the blockage of differentiation, inhibited the proliferation of all AML subtypes, and in some cases, induced cell apoptosis. Studies conducted in our laboratory have added strength to these antibodies as potential treatment for AML. Indeed, our laboratory found that treating HL60 cells with A3D8 shows a decrease in the phosphorylation of the mammalian target of Rapamycin (mTOR) kinase correlated with the inhibition of proliferation/induction of differentiation of AML cells.The relationship between the induction of differentiation and the inhibition of proliferation and the decrease of mTOR phosphorylation remains to be clarified. To study the importance of the de-phosphorylation of mTOR and the observed effect of CD44 triggering on differentiation and/or proliferation, we sought to prepare phospho-mimic mutants of the mTOR kinase that will code for a constitutively phosphorylated form of mTOR and used two main methods to express this mutant in HL60 cells: lentiviral and simple transfection (cationic-liposomal transfection).

  20. Fasting Increases Human Skeletal Muscle Net Phenylalanine Release and This Is Associated with Decreased mTOR Signaling

    Science.gov (United States)

    Vendelbo, Mikkel Holm; Møller, Andreas Buch; Christensen, Britt; Nellemann, Birgitte; Clasen, Berthil Frederik Forrest; Nair, K. Sreekumaran; Jørgensen, Jens Otto Lunde; Jessen, Niels; Møller, Niels

    2014-01-01

    Aim Fasting is characterised by profound changes in energy metabolism including progressive loss of body proteins. The underlying mechanisms are however unknown and we therefore determined the effects of a 72-hour-fast on human skeletal muscle protein metabolism and activation of mammalian target of rapamycin (mTOR), a key regulator of cell growth. Methods Eight healthy male volunteers were studied twice: in the postabsorptive state and following 72 hours of fasting. Regional muscle amino acid kinetics was measured in the forearm using amino acid tracers. Signaling to protein synthesis and breakdown were assessed in skeletal muscle biopsies obtained during non-insulin and insulin stimulated conditions on both examination days. Results Fasting significantly increased forearm net phenylalanine release and tended to decrease phenylalanine rate of disappearance. mTOR phosphorylation was decreased by ∼50% following fasting, together with reduced downstream phosphorylation of 4EBP1, ULK1 and rpS6. In addition, the insulin stimulated increase in mTOR and rpS6 phosphorylation was significantly reduced after fasting indicating insulin resistance in this part of the signaling pathway. Autophagy initiation is in part regulated by mTOR through ULK1 and fasting increased expression of the autophagic marker LC3B-II by ∼30%. p62 is degraded during autophagy but was increased by ∼10% during fasting making interpretation of autophagic flux problematic. MAFbx and MURF1 ubiquitin ligases remained unaltered after fasting indicating no change in protesomal protein degradation. Conclusions Our results show that during fasting increased net phenylalanine release in skeletal muscle is associated to reduced mTOR activation and concomitant decreased downstream signaling to cell growth. PMID:25020061

  1. MDM2 antagonists synergize with PI3K/mTOR inhibition in well-differentiated/dedifferentiated liposarcomas.

    Science.gov (United States)

    Laroche, Audrey; Chaire, Vanessa; Algeo, Marie-Paule; Karanian, Marie; Fourneaux, Benjamin; Italiano, Antoine

    2017-08-15

    Well-differentiated/dedifferentiated liposarcoma (WDLPS/DDLPS) are characterized by a consistent amplification of the MDM2 gene. The PI3K/AKT/mTOR pathway has been suggested to play also an important role in their tumorigenesis. Our goal was to determine whether combined MDM2 and PI3K/AKT/mTOR targeting is associated with higher anti-tumor activity than single agent alone in preclinical models of WDLPS/DDLPS. WDLPS/DDLPS cells were exposed to RG7388 (MDM2 antagonist) and BEZ235 (PI3K/mTOR dual inhibitor) after which apoptosis and signaling/survival pathway perturbations were monitored by flow cytometry and Western blot analysis. Xenograft mouse models were used to assess tumor growth and animal survival. Western blotting, histopathology, and tumor volume evolution were used for the assessment of treatment efficacy. The PI3K/AKT/mTOR was upregulated in up to 81% of the human WDLPS/DDLPS samples analysed. Treatment with RG7388 and BEZ235 resulted in a greater tumor activity than either drug alone with a significant difference in terms of cell viability after 72h of treatment with RG-73888 alone, BEZ235 alone and a combination of both agents. Consistent with these observations, we found a significant increase in apoptosis with the combination versus the single agent treatment alone. We then analysed the in vivo antitumor activity of RG7388 and BEZ235 in a xenograft model of DDLPS. The combination regimen significantly reduced tumor growth rate in comparison with single agent alone. Our results represent the first in vivo evidence of synergy between MDM2 and PI3K/AKT/mTOR antagonists and represent a strong rationale to evaluate the therapeutic potential of such a combination in WDLPS/DDLPS.

  2. Coupled down-regulation of mTOR and telomerase activity during fluorouracil-induced apoptosis of hepatocarcinoma Cells

    Directory of Open Access Journals (Sweden)

    Wu Mengchao

    2007-11-01

    Full Text Available Abstract Background Hepatocellular carcinoma (HCC is the most invasive and frequently diagnosed malignancy and the second leading cause of cancer death in many regions of Asia. The PI3K/Akt/mTOR signal pathway is involved in multiple cellular functions including proliferation, differentiation, tumorigenesis, and apoptosis. Up-regulation of telomerase activity is thought to be a critical step leading to cell transformation. Methods This study investigated changes in mTOR pathway and telomerase activity in hepatocarcinoma cell line SMMC-7721 treated with chemotherapeutic agent 5-fluorouracil (5-Fu. We detected apoptosis of hepatocarcinoma cells by TUNEL assay. Telomerase activity, hTERT transcription level and p- p70 S6k was demonstrated by the telomeric repeat amplification protocol and silver staining assay, Dual-Luciferase Reporter Assay and Western blot analysis respectively. Results Treating SMMC-7721 cells with 5-Fu leads to apoptosis of the cells, and reduction in telomerase activity, as well as a dramatic reduction in the activated form of p70 S6 kinase, a mTOR substrate. The 5-Fu treatment nearly abolishes transcription of hTERT (the major component of telomerase mRNA. Treating SMMC-7721 cells with Rapamycin, a specific mTOR inhibitor, significantly reduce hTERT protein level but did not affect hTERT transcription. 5-Fu and rapamycin were synergistic in regards to down-regulation of telomerase activity in hepatocarcinoma cells. Conclusion These results suggest that chemotherapeutic agent 5-Fu may down-regulate telomerase activity at both transcriptional level and PI3K/Akt/mTOR pathway-dependent post-transcriptional level to facilitate hepatocellular carcinoma cell apoptosis.

  3. GATA-Dependent Glutaminolysis Drives Appressorium Formation in Magnaporthe oryzae by Suppressing TOR Inhibition of cAMP/PKA Signaling.

    Directory of Open Access Journals (Sweden)

    Margarita Marroquin-Guzman

    2015-04-01

    Full Text Available Fungal plant pathogens are persistent and global food security threats. To invade their hosts they often form highly specialized infection structures, known as appressoria. The cAMP/ PKA- and MAP kinase-signaling cascades have been functionally delineated as positive-acting pathways required for appressorium development. Negative-acting regulatory pathways that block appressorial development are not known. Here, we present the first detailed evidence that the conserved Target of Rapamycin (TOR signaling pathway is a powerful inhibitor of appressorium formation by the rice blast fungus Magnaporthe oryzae. We determined TOR signaling was activated in an M. oryzae mutant strain lacking a functional copy of the GATA transcription factor-encoding gene ASD4. Δasd4 mutant strains could not form appressoria and expressed GLN1, a glutamine synthetase-encoding orthologue silenced in wild type. Inappropriate expression of GLN1 increased the intracellular steady-state levels of glutamine in Δasd4 mutant strains during axenic growth when compared to wild type. Deleting GLN1 lowered glutamine levels and promoted appressorium formation by Δasd4 strains. Furthermore, glutamine is an agonist of TOR. Treating Δasd4 mutant strains with the specific TOR kinase inhibitor rapamycin restored appressorium development. Rapamycin was also shown to induce appressorium formation by wild type and Δcpka mutant strains on non-inductive hydrophilic surfaces but had no effect on the MAP kinase mutant Δpmk1. When taken together, we implicate Asd4 in regulating intracellular glutamine levels in order to modulate TOR inhibition of appressorium formation downstream of cPKA. This study thus provides novel insight into the metabolic mechanisms that underpin the highly regulated process of appressorium development.

  4. Fasting increases human skeletal muscle net phenylalanine release and this is associated with decreased mTOR signaling.

    Directory of Open Access Journals (Sweden)

    Mikkel Holm Vendelbo

    Full Text Available Fasting is characterised by profound changes in energy metabolism including progressive loss of body proteins. The underlying mechanisms are however unknown and we therefore determined the effects of a 72-hour-fast on human skeletal muscle protein metabolism and activation of mammalian target of rapamycin (mTOR, a key regulator of cell growth.Eight healthy male volunteers were studied twice: in the postabsorptive state and following 72 hours of fasting. Regional muscle amino acid kinetics was measured in the forearm using amino acid tracers. Signaling to protein synthesis and breakdown were assessed in skeletal muscle biopsies obtained during non-insulin and insulin stimulated conditions on both examination days.Fasting significantly increased forearm net phenylalanine release and tended to decrease phenylalanine rate of disappearance. mTOR phosphorylation was decreased by ∼50% following fasting, together with reduced downstream phosphorylation of 4EBP1, ULK1 and rpS6. In addition, the insulin stimulated increase in mTOR and rpS6 phosphorylation was significantly reduced after fasting indicating insulin resistance in this part of the signaling pathway. Autophagy initiation is in part regulated by mTOR through ULK1 and fasting increased expression of the autophagic marker LC3B-II by ∼30%. p62 is degraded during autophagy but was increased by ∼10% during fasting making interpretation of autophagic flux problematic. MAFbx and MURF1 ubiquitin ligases remained unaltered after fasting indicating no change in protesomal protein degradation.Our results show that during fasting increased net phenylalanine release in skeletal muscle is associated to reduced mTOR activation and concomitant decreased downstream signaling to cell growth.

  5. Association of CAD, a multifunctional protein involved in pyrimidine synthesis, with mLST8, a component of the mTOR complexes

    Science.gov (United States)

    2013-01-01

    Background mTOR is a genetically conserved serine/threonine protein kinase, which controls cell growth, proliferation, and survival. A multifunctional protein CAD, catalyzing the initial three steps in de novo pyrimidine synthesis, is regulated by the phosphorylation reaction with different protein kinases, but the relationship with mTOR protein kinase has not been known. Results CAD was recovered as a binding protein with mLST8, a component of the mTOR complexes, from HEK293 cells transfected with the FLAG-mLST8 vector. Association of these two proteins was confirmed by the co-immuoprecipitaiton followed by immunoblot analysis of transfected myc-CAD and FLAG-mLST8 as well as that of the endogenous proteins in the cells. Analysis using mutant constructs suggested that CAD has more than one region for the binding with mLST8, and that mLST8 recognizes CAD and mTOR in distinct ways. The CAD enzymatic activity decreased in the cells depleted of amino acids and serum, in which the mTOR activity is suppressed. Conclusion The results obtained indicate that mLST8 bridges between CAD and mTOR, and plays a role in the signaling mechanism where CAD is regulated in the mTOR pathway through the association with mLST8. PMID:23594158

  6. The El Tor biotype of Vibrio cholerae exhibits a growth advantage in the stationary phase in mixed cultures with the classical biotype.

    Science.gov (United States)

    Pradhan, Subhra; Baidya, Amit K; Ghosh, Amalendu; Paul, Kalidas; Chowdhury, Rukhsana

    2010-02-01

    Vibrio cholerae strains of the O1 serogroup that typically cause epidemic cholera can be classified into two biotypes, classical and El Tor. The El Tor biotype emerged in 1961 and subsequently displaced the classical biotype as a cause of cholera throughout the world. In this study we demonstrate that when strains of the El Tor and classical biotypes were cocultured in standard LB medium, the El Tor strains clearly had a competitive growth advantage over the classical biotype starting from the late stationary phase and could eventually take over the population. The classical biotype produces extracellular protease(s) in the stationary phase, and the amounts of amino acids and small peptides in the late stationary and death phase culture filtrates of the classical biotype were higher than those in the corresponding culture filtrates of the El Tor biotype. The El Tor biotype cells could utilize the amino acids more efficiently than the classical biotype under the alkaline pH of the stationary phase cultures but not in medium buffered to neutral pH. The growth advantage of the El Tor biotype was also observed in vivo using the ligated rabbit ileal loop and infant mouse animal models.

  7. Clinical significance of chemokine receptor CXCR4 and mammalian target of rapamycin (mTOR) expression in patients with diffuse large B-cell lymphoma.

    Science.gov (United States)

    Xu, Zi-Zhen; Shen, Jian-Kang; Zhao, Shu-Qing; Li, Jun-Min

    2017-09-27

    To assess the relevance of C-X-C chemokine receptor type 4 (CXCR4) and mammalian target of rapamycin (mTOR) to large-B-cell lymphoma (DLBCL), levels of protein expression were measured in 56 DLBCL patients who had received rituximab-based therapy. Of these, 34 were positive for CXCR4 expression (60.7%) and 31 for mTOR (55.4%). CXCR4 expression was positively correlated with mTOR expression (r = 0.602; p = .000). CXCR4 expression was significantly associated with high lactate dehydrogenase (LDH) level (p = .009), high IPI score (p = .030) and non-GCB subtype (p = .006). Furthermore, the expression levels of CXCR4 and mTOR were negatively correlated with the chance of remission (p < .05). Kaplan-Meier analysis indicated significantly shorter progression-free survival (PFS) and overall survival (OS) in patients positive for CXCR4 and mTOR expression. The combination therapy with CXCR4 inhibitor WZ811 and mTOR inhibitor everolimus showed syncergistic effect in DLBCL cell lines. These results suggest that the expression of CXCR4 and mTOR may be suitable as biomarkers of the prognosis of DLBCL and for development of new therapeutic strategies.

  8. The dual specificity PI3K/mTOR inhibitor PKI-587 displays efficacy against T-cell acute lymphoblastic leukemia (T-ALL).

    Science.gov (United States)

    Gazi, Mohiuddin; Moharram, Sausan A; Marhäll, Alissa; Kazi, Julhash U

    2017-04-28

    Although significant improvements have been made in the treatment of acute lymphoblastic leukemia (ALL), there is a substantial subset of high-risk T-cell ALL (T-ALL) patients with relatively poor prognosis. Like in other leukemia types, alterations of the PI3K/mTOR pathway are predominant in ALL which is also responsible for treatment failure and relapse. In this study, we show that relapsed T-ALL patients display an enrichment of the PI3K/mTOR pathway. Using a panel of inhibitors targeting multiple components of the PI3K/mTOR pathway, we observed that the dual-specific PI3K/mTOR inhibitor PKI-587 was the most selective inhibitor for T-ALL cells dependent on the PI3K/mTOR pathway. Furthermore, we observed that PKI-587 blocked proliferation and colony formation of T-ALL cell lines. Additionally, PKI-587 selectively abrogated PI3K/mTOR signaling without affecting MAPK signaling both in in vitro and in vivo. Inhibition of the PI3K/mTOR pathway using PKI-587 delayed tumor progression, reduced tumor load and enhanced the survival rate in immune-deficient mouse xenograft models without inducing weight loss in the inhibitor treated mice. This preclinical study shows beneficial effects of PKI-587 on T-ALL that warrants further investigation in the clinical setting. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. MLN0128, a novel mTOR kinase inhibitor, disrupts survival signaling and triggers apoptosis in AML and AML stem/ progenitor cells.

    Science.gov (United States)

    Zeng, Zhihong; Wang, Rui-Yu; Qiu, Yi Hua; Mak, Duncan H; Coombes, Kevin; Yoo, Suk Young; Zhang, Qi; Jessen, Katti; Liu, Yi; Rommel, Christian; Fruman, David A; Kantarjian, Hagop M; Kornblau, Steven M; Andreeff, Michael; Konopleva, Marina

    2016-08-23

    mTOR activation leads to enhanced survival signaling in acute myeloid leukemia (AML) cells. The active-site mTOR inhibitors (asTORi) represent a promising new approach to targeting mTOR in AKT/mTOR signaling. MLN0128 is an orally-administered, second-generation asTORi, currently in clinical development. We examined the anti-leukemic effects and the mechanisms of action of MLN0128 in AML cell lines and primary samples, with a particular focus on its effect in AML stem/progenitor cells. MLN0128 inhibited cell proliferation and induced apoptosis in AML by attenuating the activity of mTOR complex 1 and 2. Using time-of-flight mass cytometry, we demonstrated that MLN0128 selectively targeted and functionally inhibited AML stem/progenitor cells with high AKT/mTOR signaling activity. Using the reverse-phase protein array technique, we measured expression and phosphorylation changes in response to MLN0128 in 151 proteins from 24 primary AML samples and identified several pro-survival pathways that antagonize MLN0128-induced cellular stress. A combined blockade of AKT/mTOR signaling and these pro-survival pathways facilitated AML cell killing. Our findings provide a rationale for the clinical use of MLN0128 to target AML and AML stem/progenitor cells, and support the use of combinatorial multi-targeted approaches in AML therapy.

  10. A replication and methodological critique of the study "Evaluating drug trafficking on the Tor Network"

    DEFF Research Database (Denmark)

    Munksgaard, Rasmus; Demant, Jakob Johan; Branwen, Gwern

    2016-01-01

    The development of cryptomarkets has gained increasing attention from academics, including growing scientific literature on the distribution of illegal goods using cryptomarkets. Dolliver's 2015 article “Evaluating drug trafficking on the Tor Network: Silk Road 2, the Sequel” addresses this theme...... by evaluating drug trafficking on one of the most well-known cryptomarkets, Silk Road 2.0. The research on cryptomarkets in general—particularly in Dolliver's article—poses a number of new questions for methodologies. This commentary is structured around a replication of Dolliver's original study....... The replication study is not based on Dolliver's original dataset, but on a second dataset collected applying the same methodology. We have found that the results produced by Dolliver differ greatly from our replicated study. While a margin of error is to be expected, the inconsistencies we found are too great...

  11. A Septuaginta (LXX: a Torá na diáspora judaico-­helenista

    Directory of Open Access Journals (Sweden)

    Pedro Paulo Alves dos Santos

    2008-03-01

    Full Text Available A versão da LXX é uma obra de tradução, por isso mesmo, pode ser entendida como uma obra de interpretação. Enquanto projeto de tradução do Pentateuco, e posteriormente, de todos os textos hebraicos à disposição, é considerada como a Torá greco-helenística. Nesse sentido, a versão constituiu-se numa obra da exegese judaica antiga. Neste artigo iremos abordar esta questão em uma dupla face. De um lado, como uma exigência da comunidade judaica imersa no Helenismo, obra dos judeus de Alexandria, entregue à Biblioteca de Ptolomeu IV. Do outro, sua fortuna crítica.

  12. Miologia do membro torácico da paca (Cuniculus paca)

    OpenAIRE

    Leal,Leonardo M.; Silva,Juliana A.C.E.; Oliveira,Fabricio S. de; Tais H.C. Sasahara; Machado,Marcia R.F.

    2016-01-01

    Resumo: Objetivou-se descrever os músculos do membro torácico da paca (Cuniculus paca Linnaeus, 1766), mediante dissecação anatômica dessa região. Foram utilizadas cinco Cuniculus paca adultas, machos e fêmeas, pesando entre cinco e 10kg do plantel de pacas do setor de Animais Silvestres da FCAV, Unesp, Jaboticabal/SP. Os animais foram fixados em formoldeído a 10% e conservados em solução salina a 30% para dissecação anatômica da musculatura do ombro, braço e antebraço, identificando-se a ori...

  13. Solute carriers (SLCs) identified and characterized from kidney transcriptome of golden mahseer (Tor putitora) (Fam: Cyprinidae).

    Science.gov (United States)

    Barat, Ashoktaru; Sahoo, Prabhati Kumari; Kumar, Rohit; Pande, Veena

    2016-10-01

    The solute carriers (SLC) are trans-membrane proteins, those regulate the transport of various substances (sugars, amino acids, nucleotides, inorganic cations/anions, metals, drugs etc.) across the cell membrane. There are more than 338 solute carriers (slc) reported in fishes that play crucial role in cellular influx and efflux. The study of solute carrier families may reveal many answers regarding the function of transporter genes in the species and their effect in the existing environment. Therefore, we performed RNA sequencing of kidney tissue of the golden mahseer (Tor putitora) using Illumina platform to identify the solute carrier families and characterized 24 putative functional genes under 15 solute carrier families. Out of 24 putative functional genes, 11 genes were differentially expressed in different tissues (head kidney, trunk kidney, spleen, liver, gill, muscle, intestine and brain) using qRT-PCR assay. The slc5a1, slc5a12, slc12a3, slc13a3, slc22a13 and slc26a6 were highly expressed in kidney. The slc15a2, slc25a47, slc33a1 and slc38a2 were highly expressed in brain and slc30a5 was over-expressed in gill. The unrooted phylogenetic trees of slc2, slc5, slc13 and slc33 were constructed using amino acid sequences of Homo sapiens, Salmo salar, Danio rerio, Cyprinus carpio and Tor putitora. It appears that all the putative solute carrier families are very much conserved in human and fish species including the present fish, golden mahseer. This study provides the first hand database of solute carrier families particularly transporter encoding proteins in the species. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Characterization of Vibrio cholerae O1 El Tor biotype variant clinical isolates from Bangladesh and Haiti, including a molecular genetic analysis of virulence genes.

    Science.gov (United States)

    Son, Mike S; Megli, Christina J; Kovacikova, Gabriela; Qadri, Firdausi; Taylor, Ronald K

    2011-11-01

    Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and a representative strain from the 2010 Haiti cholera outbreak. We observed that all 11 strains produced increased CT (2- to 10-fold) compared to that of wild-type El Tor strains under in vitro inducing conditions, but they possessed various TcpA and ToxT expression profiles. Particularly, El Tor variant MQ1795, which produced the highest level of CT and very high levels of TcpA and ToxT, demonstrated hypervirulence compared to the virulence of El Tor wild-type strains in the infant mouse cholera model. Additional genotypic and phenotypic tests were conducted to characterize the variants, including an assessment of biotype-distinguishing characteristics. Notably, the sequencing of ctxB in some El Tor variants revealed two copies of classical ctxB, one per chromosome, contrary to previous reports that located ctxAB only on the large chromosome of El Tor biotype strains.

  15. Characterization of Vibrio cholerae O1 El Tor Biotype Variant Clinical Isolates from Bangladesh and Haiti, Including a Molecular Genetic Analysis of Virulence Genes ▿

    Science.gov (United States)

    Son, Mike S.; Megli, Christina J.; Kovacikova, Gabriela; Qadri, Firdausi; Taylor, Ronald K.

    2011-01-01

    Vibrio cholerae serogroup O1, the causative agent of the diarrheal disease cholera, is divided into two biotypes: classical and El Tor. Both biotypes produce the major virulence factors toxin-coregulated pilus (TCP) and cholera toxin (CT). Although possessing genotypic and phenotypic differences, El Tor biotype strains displaying classical biotype traits have been reported and subsequently were dubbed El Tor variants. Of particular interest are reports of El Tor variants that produce various levels of CT, including levels typical of classical biotype strains. Here, we report the characterization of 10 clinical isolates from the International Centre for Diarrhoeal Disease Research, Bangladesh, and a representative strain from the 2010 Haiti cholera outbreak. We observed that all 11 strains produced increased CT (2- to 10-fold) compared to that of wild-type El Tor strains under in vitro inducing conditions, but they possessed various TcpA and ToxT expression profiles. Particularly, El Tor variant MQ1795, which produced the highest level of CT and very high levels of TcpA and ToxT, demonstrated hypervirulence compared to the virulence of El Tor wild-type strains in the infant mouse cholera model. Additional genotypic and phenotypic tests were conducted to characterize the variants, including an assessment of biotype-distinguishing characteristics. Notably, the sequencing of ctxB in some El Tor variants revealed two copies of classical ctxB, one per chromosome, contrary to previous reports that located ctxAB only on the large chromosome of El Tor biotype strains. PMID:21880975

  16. Inhibition of mTOR is required for optimal antitumor effect of HER2 inhibitors against HER2-overexpressing cancer cells

    Science.gov (United States)

    Miller, Todd W.; Forbes, James T.; Shah, Chirayu; Wyatt, Shelby K.; Manning, H. Charles; Olivares, Maria G.; Sanchez, Violeta; Dugger, Teresa C.; Granja, Nara de Matos; Narasanna, Archana; Cook, Rebecca S.; Kennedy, J. Phillip; Lindsley, Craig W.; Arteaga, Carlos L.

    2009-01-01

    Purpose A significant fraction of HER2-overexpressing breast cancers exhibit resistance to the HER2 antibody trastuzumab. Hyperactivity of the phosphatidylinositol-3 kinase (PI3K)/AKT pathway confers trastuzumab resistance, and mTOR is a major downstream effector of PI3K/AKT. Therefore, we examined whether mTOR inhibitors synergize with trastuzumab. Experimental Design Immunocompetent mice bearing HER2-positive mammary tumors were treated with trastuzumab, the mTOR inhibitor rapamycin, or the combination. Mice were imaged for tumor cell death using an optical Annexin-V probe and with [18F]FDG-PET. The signaling and growth effects of the mTOR inhibitor RAD001 on HER2+ cells treated with trastuzumab or lapatinib were evaluated. Results Treatment of mice with trastuzumab plus rapamycin was more effective than single-agent treatments, inducing complete regression of 26/26 tumors. The combination induced tumor cell death (Annexin-V binding) and inhibited FDG uptake. Rapamycin inhibited mTOR and tumor cell proliferation as determined by phospho-S6 and Ki67 immunohistochemistry, respectively. In culture, the combination of RAD001 plus trastuzumab inhibited cell growth more effectively than either drug alone. Trastuzumab partially decreased PI3K but not mTOR activity. Knockdown of TSC2 resulted in HER2-independent activation of mTOR and dampened the response to trastuzumab and lapatinib. Treatment with the HER2 inhibitor lapatinib decreased phospho-S6 and growth in TSC2-expressing but not in TSC2-knockdown cells. Conclusions Inhibition of PI3K and mTOR are required for the growth inhibitory effect of HER2 antagonists. These findings collectively support the combined use of trastuzumab and mTOR inhibitors for the treatment of HER2+ breast cancer. PMID:19934303

  17. Effects of ketamine administration on mTOR and reticulum stress signaling pathways in the brain after the infusion of rapamycin into prefrontal cortex.

    Science.gov (United States)

    Abelaira, Helena M; Réus, Gislaine Z; Ignácio, Zuleide M; Dos Santos, Maria Augusta B; de Moura, Airam B; Matos, Danyela; Demo, Júlia P; da Silva, Júlia B I; Michels, Monique; Abatti, Mariane; Sonai, Beatriz; Dal Pizzol, Felipe; Carvalho, André F; Quevedo, João

    2017-04-01

    Recent studies show that activation of the mTOR signaling pathway is required for the rapid antidepressant actions of glutamate N-methyl-D-aspartate (NMDA) receptor antagonists. A relationship between mTOR kinase and the endoplasmic reticulum (ER) stress pathway, also known as the unfolded protein response (UPR) has been shown. We evaluate the effects of ketamine administration on the mTOR signaling pathway and proteins of UPR in the prefrontal cortex (PFC), hippocampus, amygdala and nucleus accumbens, after the inhibiton of mTOR signaling in the PFC. Male adult Wistar rats received pharmacological mTOR inhibitor, rapamycin (0.2 nmol), or vehicle into the PFC and then a single dose of ketamine (15 mg/kg, i.p.). The immunocontent of mTOR, eukaryotic initiation factor 4E-binding protein 1 (4E-BP1), eukaryotic elongation factor 2 kinase (eEF2K) homologous protein (CHOP), PKR-like ER kinase (PERK) and inositol-requiring enzyme 1 (IRE1) - alpha were determined in the brain. The mTOR levels were reduced in the rapamycin group treated with saline and ketamine in the PFC; p4EBP1 levels were reduced in the rapamycin group treated with ketamine in the PFC and nucleus accumbens; the levels of peEF2K were increased in the PFC in the vehicle group treated with ketamine and reduced in the rapamycin group treated with ketamine. The PERK and IRE1-alpha levels were decreased in the PFC in the rapamycin group treated with ketamine. Our results suggest that mTOR signaling inhibition by rapamycin could be involved, at least in part, with the mechanism of action of ketamine; and the ketamine antidepressant on ER stress pathway could be also mediated by mTOR signaling pathway in certain brain structures. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Regression of cardiac growth in kidney transplant recipients using anti-m-TOR drugs plus RAS blockers: a controlled longitudinal study.

    Science.gov (United States)

    Hernández, Domingo; Ruiz-Esteban, Pedro; Gaitán, Daniel; Burgos, Dolores; Mazuecos, Auxiliadora; Collantes, Rocío; Briceño, Eva; Palma, Eulalia; Cabello, Mercedes; González-Molina, Miguel; De Mora, Manuel

    2014-04-23

    Left ventricular hypertrophy (LVH) is common in kidney transplant (KT) recipients. LVH is associated with a worse outcome, though m-TOR therapy may help to revert this complication. We therefore conducted a longitudinal study to assess morphological and functional echocardiographic changes after conversion from CNI to m-TOR inhibitor drugs in nondiabetic KT patients who had previously received RAS blockers during the follow-up. We undertook a 1-year nonrandomized controlled study in 30 non-diabetic KT patients who were converted from calcineurin inhibitor (CNI) to m-TOR therapy. A control group received immunosuppressive therapy based on CNIs. Two echocardiograms were done during the follow-up. Nineteen patients were switched to SRL and 11 to EVL. The m-TOR group showed a significant reduction in LVMi after 1 year (from 62 ± 22 to 55 ± 20 g/m2.7; P=0.003, paired t-test). A higher proportion of patients showing LVMi reduction was observed in the m-TOR group (53.3 versus 29.3%, P=0.048) at the study end. In addition, only 56% of the m-TOR patients had LVH at the study end compared to 77% of the control group (P=0.047). A significant change from baseline in deceleration time in early diastole was observed in the m-TOR group compared with the control group (P=0.019). Switching from CNI to m-TOR therapy in non-diabetic KT patients may regress LVH, independently of blood pressure changes and follow-up time. This suggests a direct non-hemodynamic effect of m-TOR drugs on cardiac mass.

  19. Lithium protects against methamphetamine-induced neurotoxicity in PC12 cells via Akt/GSK3β/mTOR pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jintao; Zhu, Dexiao; Zhang, Jing; Li, Guibao [Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong, 250012 (China); Liu, Zengxun [Department of Psychiatry, School of Medicine, Shandong University, Jinan, Shandong, 250012 China (China); Sun, Jinhao, E-mail: sunjinhao@gmail.com [Department of Anatomy, School of Medicine, Shandong University, Jinan, Shandong, 250012 (China)

    2015-09-25

    Methamphetamine (MA) is neurotoxic, especially in dopaminergic neurons. Long-lasting exposure to MA causes psychosis and increases the risk of Parkinson's disease. Lithium (Li) is a known mood stabilizer and has neuroprotective effects. Previous studies suggest that MA exposure decreases the phosphorylation of Akt/GSK3β pathway in vivo, whereas Li facilitates the phosphorylation of Akt/GSK3β pathway. Moreover, GSK3β and mTOR are implicated in the locomotor sensitization induced by psychostimulants and mTOR plays a critical role in MA induced toxicity. However, the effect of MA on Akt/GSK3β/mTOR pathway has not been fully investigated in vitro. Here, we found that MA exposure significantly dephosphorylated Akt/GSK3β/mTOR pathway in PC12 cells. In addition, Li remarkably attenuated the dephosphorylation effect of MA exposure on Akt/GSK3β/mTOR pathway. Furthermore, Li showed obvious protective effects against MA toxicity and LY294002 (Akt inhibitor) suppressed the protective effects of Li. Together, MA exposure dephosphorylates Akt/GSK3β/mTOR pathway in vitro, while lithium protects against MA-induced neurotoxicity via phosphorylation of Akt/GSK3β/mTOR pathway. - Highlights: • Lithium protects against methamphetamine-induced neurotoxicity in vitro. • Methamphetamine exposure dephosphorylates Akt/GSK3β/mTOR pathway. • Lithium attenuates methamphetamine-induced toxicity via phosphorylating Akt/GSK3β/mTOR pathway.

  20. 3D-QSAR, Virtual Screening, Docking and Design of Dual PI3K/mTOR Inhibitors with Enhanced Antiproliferative Activity.

    Science.gov (United States)

    Oluić, Jelena; Nikolic, Katarina; Vucicevic, Jelica; Gagic, Zarko; Filipic, Slavica; Agbaba, Danica

    2017-08-10

    Altered activity of PI3K/mTOR signaling pathway is one of the most common aberrations found in various forms of neoplastic lesions. Dual inhibition of PI3K and mTOR represents a reasonably attractive concept in potential cancer treatment. The main aim of this work was to design novel PI3K/mTOR inhibitors with enhanced antiproliferative activity. 3D-QSAR pharmacophore modeling studies were performed on two groups comprised of 37 and 48 dual PI3K/mTOR inhibitors. Obtained 3D-pharmacophores were used in design of new dual PI3K/mTOR inhibitors. Based on the in silico ADMET data, structure-based virtual screening and docking studies, the most promising novel candidates were selected. Four reliable PLS models with good statistical parameters (q2 = 0.72, r2 pred = 0.93; q2 = 0.81, r2 pred= 0.88 for 3D-QSAR (mTOR) models and q2 = 0.79, r2pred = 0.93; q2 = 0.79, r2 pred = 0.94 for 3D-QSAR (PI3K) models) were obtained and new highly selective and potent dual PI3K/mTOR inhibitors were designed. Further in silico ADMET profiling of the designed compounds selected the most promising novel PI3K/mTOR inhibitors as drug candidates. Results of the 3D-QSAR studies were confirmed by structure-based virtual screening protocol that identified selected designed compounds as a best fit for PI3K and mTOR receptors. Molecular docking studies on PI3K and mTOR crystal structures revealed the key active site residues involved in binding of PI3K/mTOR ligands. After combining the results of 3D-QSAR, ADMET profiling, virtual screening and docking, compounds 56-57 and 56-62 were chosen as the most promising new dual PI3K/mTOR inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  1. AKT/mTOR substrate P70S6K is frequently phosphorylated in gallbladder cancer tissue and cell lines

    Directory of Open Access Journals (Sweden)

    Leal P

    2013-10-01

    Full Text Available Pamela Leal,1,* Patricia Garcia,2,* Alejandra Sandoval,1 Kurt Buchegger,1 Helga Weber,1 Oscar Tapia,1 Juan C Roa1,2 1Department of Pathology, Universidad de La Frontera, Center of Genetical and Immunological Studies-Scientific and Technological Bioresource Nucleus, Temuco, 2Department of Pathology, Pontificia Universidad Catolica de Chile, Santiago, Chile *These authors contributed equally to this paperBackground: Gallbladder carcinoma is a highly malignant tumor and a public health problem in some parts of the world. It is characterized by a poor prognosis and its resistance to radio and chemotherapy. There is an urgent need to develop novel therapeutic alternatives for the treatment of gallbladder carcinoma. The mammalian target of the rapamycin (mTOR signaling pathway is activated in about 50% of human malignancies, and its role in gallbladder carcinoma has previously been suggested. In the present study, we investigated the phosphorylation status of the mTOR substrate p70S6K in preneoplastic and neoplastic gallbladder tissues and evaluated the effect of three mTOR inhibitors on cell growth and migration in gallbladder carcinoma cell lines.Methods: Immunohistochemical staining of phospho-p70S6K was analyzed in 181 gallbladder carcinoma cases, classified according to lesion type as dysplasia, early carcinoma, or advanced carcinoma. Protein expression of AKT/mTOR members was also evaluated in eight gallbladder carcinoma cell lines by Western blot analysis. We selected two gallbladder carcinoma cell lines (G415 and TGBC-2TKB to evaluate the effect of rapamycin, RAD001, and AZD8055 on cell viability, cell migration, and protein expression.Results: Our results showed that phospho-p70S6K is highly expressed in dysplasia (66.7%, 12/18, early cancer (84.6%, 22/26, and advanced cancer (88.3%, 121/137. No statistical correlation was observed between phospho-p70S6K status and any clinical or pathological features, including age, gender, ethnicity, wall

  2. Effects of mTOR inhibition on cardiac and adipose tissue pathology and glucose metabolism in rats with metabolic syndrome.

    Science.gov (United States)

    Uchinaka, Ayako; Yoneda, Mamoru; Yamada, Yuichiro; Murohara, Toyoaki; Nagata, Kohzo

    2017-08-01

    The mammalian target of rapamycin (mTOR) is a regulator of metabolism and is implicated in pathological conditions such as obesity and diabetes. We aimed to investigate the role of mTOR in obesity. A new animal model of metabolic syndrome (MetS), named DahlS.Z-Lepr(fa) /Lepr(fa) (DS/obese) rats was established previously in our laboratory. In this study, we used this model to evaluate the effects of mTOR inhibition on cardiac and adipose tissue pathology and glucose metabolism. DS/obese rats were treated with the mTOR inhibitor, everolimus, (0.83 mg/kg per day, per os) for 4 weeks at 9 weeks of age. Age-matched homozygous lean (DahlS.Z-Lepr(+) /Lepr(+) or DS/lean) littermates of DS/obese rats were used as controls. Treatment with everolimus ameliorated hypertension, left ventricular (LV) hypertrophy and fibrosis, and LV diastolic dysfunction, and attenuated cardiac oxidative stress and inflammation in DS/obese rats, but had no effect on these parameters in DS/lean rats. Treatment with everolimus reduced Akt Thr308 phosphorylation in the heart of DS/obese rats. It also alleviated obesity, hyperphagia, adipocyte hypertrophy, and adipose tissue inflammation in DS/obese rats. Everolimus treatment exacerbated glucose intolerance, but did not affect Akt phosphorylation levels in the fat or liver in these rats. Pancreatic β-cell mass was increased in DS/obese rats compared with that in DS/lean rats and this effect was attenuated by everolimus. Activation of mTOR signaling contributes to the pathophysiology of MetS and its associated complications. And mTOR inhibition with everolimus ameliorated obesity as well as cardiac and adipose tissue pathology, but exacerbated glucose metabolism in rats with MetS. © 2017 The Authors. Pharmacology Research & Perspectives published by John Wiley & Sons Ltd, British Pharmacological Society and American Society for Pharmacology and Experimental Therapeutics.

  3. Inositol Hexaphosphate Inhibits Proliferation and Induces Apoptosis of Colon Cancer Cells by Suppressing the AKT/mTOR Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Małgorzata Kapral

    2017-10-01

    Full Text Available Abstract: AKT, a serine/threonine protein kinase and mammalian target of rapamycin (mTOR plays a critical role in the proliferation and resistance to apoptosis that are essential to the development and progression of colon cancer. Therefore, AKT/mTOR signaling pathway has been recognized as an attractive target for anticancer therapy. Inositol hexaphosphate (InsP6, a natural occurring phytochemical, has been shown to have both preventive and therapeutic effects against various cancers, however, its exact molecular mechanisms of action are not fully understood. The aim of the in vitro study was to investigate the anticancer activity of InsP6 on colon cancer with the focus on inhibiting the AKT1 kinase and p70S6K1 as mTOR effector, in relation to proliferation and apoptosis of cells. The colon cancer Caco-2 cells were cultured using standard techniques and exposed to InsP6 at different concentrations (1 mM, 2.5 mM and 5 mM. Cellular proliferative activity was monitored by 5-bromo-2′-deoxyuridine (BrdU incorporation into cellular DNA. Flow cytometric analysis was performed for cell cycle progression and apoptosis studies. Real-time RT-qPCR was used to validate mRNA levels of CDNK1A, CDNK1B, CASP3, CASP9, AKT1 and S6K1 genes. The concentration of p21 protein as well as the activities of caspase 3, AKT1 and p70S6K1 were determined by the ELISA method. The results revealed that IP6 inhibited proliferation and stimulated apoptosis of colon cancer cells. This effect was mediated by an increase in the expression of genes encoding p21, p27, caspase 3, caspase 9 as well a decrease in transcription of AKT1 and S6K1. InsP6 suppressed phosphorylation of AKT1 and p70S6K1, downstream effector of mTOR. Based on these studies it may be concluded that InsP6 can reduce proliferation and induce apoptosis through inhibition of the AKT/mTOR pathway and mTOR effector followed by modulation of the expression and activity of several key components of these pathways in

  4. Inorganic polyphosphate promotes cyclin D1 synthesis through activation of mTOR/Wnt/β-catenin signaling in endothelial cells.

    Science.gov (United States)

    Hassanian, S M; Ardeshirylajimi, A; Dinarvand, P; Rezaie, A R

    2016-11-01

    Essentials Polyphosphate (polyP) activates mTOR but its role in Wnt/β-catenin signaling is not known. PolyP-mediated cyclin D1 expression (β-catenin target gene) was monitored in endothelial cells. PolyP and boiled platelet-releasates induced the expression of cyclin D1 by similar mechanisms. PolyP establishes crosstalk between mTOR and Wnt/β-catenin signaling in endothelial cells. Background Inorganic polyphosphate (polyP) elicits intracellular signaling responses in endothelial cells through activation of mTOR complexes 1 and 2. Glycogen synthase kinase 3 (GSK-3) is known to be a negative regulator of mTOR and Wnt/β-catenin signaling pathways. Objective The objective of this study was to investigate the effect of polyP on the expression, degradation and subcellular localization of the Wnt/β-catenin target gene, cyclin D1, in endothelial cells. Methods Regulation of cyclin D1 expression, phosphorylation and subcellular localization by polyP or platelet releasates was monitored in the absence and presence of pharmacological inhibitors and/or siRNA for specific molecules of the upstream mTOR/Wnt/β-catenin signaling network by established methods. Results Both synthetic polyP and boiled-platelet releasates induced the phosphorylation-dependent inactivation of GSK-3, thereby increasing the expression and nuclear localization, but inhibiting the degradation of cyclin D1. Inhibitors of mTORC1 (PI3K, AKT, PLC, PKC), rapamycin and siRNA for raptor (mTORC1-specific component) and β-catenin, all inhibited polyP-mediated regulation of cyclin D1 expression, phosphorylation and subcellular localization in endothelial cells. The signaling effect of polyP was effectively inhibited by the recombinant extracellular domain of the receptor for advanced glycation end products (RAGE) and/or by the RAGE siRNA. Specific pharmacological inhibitors and siRNA knockdown of ERK1/2 and NF-κB pathways indicated that polyP-mediated cyclin D1 expression and nuclear localization are IKK

  5. Inhibition of the mammalian target of rapamycin (mTOR in advanced pancreatic cancer: results of two phase II studies

    Directory of Open Access Journals (Sweden)

    Zhang Yujian

    2010-07-01

    Full Text Available Abstract Background The phosphoinositide 3-kinase (PI3K/Akt pathway is constitutively activated in pancreatic cancer and the mammalian target of rapamycin (mTOR kinase is an important mediator for its signaling. Our recent in vitro studies suggest that prolonged exposure of pancreatic cancer cells to mTOR inhibitors can promote insulin receptor substrate-PI3K interactions and paradoxically increase Akt phosphorylation and cyclin D1 expression in pancreatic cancer cells (negative feedback loop. The addition of erlotinib to rapamycin can down-regulate rapamycin-stimulated Akt and results in synergistic antitumor activity with erlotinib in preclinical tumor models. Methods Two studies prospectively enrolled adult patients with advanced pancreatic cancer, Eastern Cooperative Oncology Group performance status 0-1, adequate hematologic, hepatic and renal parameters and measurable disease. In Study A, temsirolimus was administered intravenously at 25 mg weekly. In Study B, everolimus was administered orally at 30 mg weekly and erlotinib was administered at 150 mg daily. The primary endpoint in both studies was overall survival at 6 months. Secondary endpoints included time to progression, progression-free survival, overall survival, response rate, safety and toxicity. Pretreatment tumor biopsies were analyzed by immunofluorescence and laser scanning cytometry for the expression of pmTOR/mTOR, pAkt/Akt, pErk/Erk, pS6, p4EBP-1 and PTEN. Results Five patients enrolled in Study A; Two patients died within a month (rapid disease progression and hemorrhagic stroke, respectively. One patient developed dehydration and another developed asthenia. Sixteen patients enrolled in Study B.: 12 males, all ECOG PS = 1. Median cycles = 1 (range 1-2. Grade 4 toxicity: hyponatremia (n = 1, Grade 3: diarrhea (n = 1, cholangitis (n = 3, hyperglycemia (n = 1, fatigue (n = 1. Grade 2: pneumonia (n = 2, dehydration (n = 2, nausea (n = 2, neutropenia (n = 1, mucositis (n = 2

  6. Genetic susceptibility to environmental toxicants

    DEFF Research Database (Denmark)

    2001-01-01

    The toxicological challenges to the chemical industry have in recent years been greatly affected by the rapid innovation and development of analytical, molecular and genetic technologies. ECETOC recognises the importance of developing the technical and intellectual skill bases in academia...... and industrial based laboratories to meet the rapid development of the science base of toxicology. As the technology to determine genetic susceptibility develops, so scientist will be able to describe altered gene expression provoked by chemicals long before they are able to offer valid interpretations...... of their meaning. A potential for inadvertently raising concerns over the effect of chemicals in experimental animals or man, or even the intentional misrepresentation of results to suggest chemicals are “playing” with our genes is enormous. History has shown that some individuals and groups in society are willing...

  7. Drosophila insulin and target of rapamycin (TOR pathways regulate GSK3 beta activity to control Myc stability and determine Myc expression in vivo

    Directory of Open Access Journals (Sweden)

    Parisi Federica

    2011-09-01

    Full Text Available Abstract Background Genetic studies in Drosophila melanogaster reveal an important role for Myc in controlling growth. Similar studies have also shown how components of the insulin and target of rapamycin (TOR pathways are key regulators of growth. Despite a few suggestions that Myc transcriptional activity lies downstream of these pathways, a molecular mechanism linking these signaling pathways to Myc has not been clearly described. Using biochemical and genetic approaches we tried to identify novel mechanisms that control Myc activity upon activation of insulin and TOR signaling pathways. Results Our biochemical studies show that insulin induces Myc protein accumulation in Drosophila S2 cells, which correlates with a decrease in the activity of glycogen synthase kinase 3-beta (GSK3β a kinase that is responsible for Myc protein degradation. Induction of Myc by insulin is inhibited by the presence of the TOR inhibitor rapamycin, suggesting that insulin-induced Myc protein accumulation depends on the activation of TOR complex 1. Treatment with amino acids that directly activate the TOR pathway results in Myc protein accumulation, which also depends on the ability of S6K kinase to inhibit GSK3β activity. Myc upregulation by insulin and TOR pathways is a mechanism conserved in cells from the wing imaginal disc, where expression of Dp110 and Rheb also induces Myc protein accumulation, while inhibition of insulin and TOR pathways result in the opposite effect. Our functional analysis, aimed at quantifying the relative contribution of Myc to ommatidial growth downstream of insulin and TOR pathways, revealed that Myc activity is necessary to sustain the proliferation of cells from the ommatidia upon Dp110 expression, while its contribution downstream of TOR is significant to control the size of the ommatidia. Conclusions Our study presents novel evidence that Myc activity acts downstream of insulin and TOR pathways to control growth in Drosophila. At

  8. Transcriptomic differences of genes in the avian target of rapamycin (avTOR) pathway in a divergent line of meat-type chickens selected for feed efficiency.

    Science.gov (United States)

    Lee, J; Aggrey, S E

    2016-06-30

    Avian target of rapamycin (avTOR) is a highly conserved serine-threonine kinase that serves as an intracellular energy and nutrient sensor and regulates cell division, growth, and apoptosis. The role of avTOR in mediating feed intake and growth in poultry is unknown. We studied avTOR signaling activities in duodenum and liver tissues at days 35 and 42 in chickens divergently selected for low (LRFI) or high (HRFI) residual feed intake. The differential expression of genes involved in the avTOR pathway was assayed using real-time polymerase chain reaction. In the duodenum, avTOR was up-regulated in the LRFI chickens at both time points as compared with the HRFI chickens. Other genes found to be differentially expressed at day 35 included v-akt murine thymoma viral oncogene homolog, eukaryotic translation elongation factor 2, eukaryotic translation initiation factor 4E binding protein 1, 3-phosphoinositide dependent protein kinase-1, ribosomal protein S6 kinase, 70 kDa, polypeptide 1 (RPS6KP1), avTOR associated protein, LST8 homolog, ghrelin, phosphoinositide-3-kinase (PI3K), forkhead box O1, and p53 E3 ubiquitin protein ligase homolog (MDM2). At day 42, there was no change in the expression of the avTOR target RPS6KP1 or MDM2. In the liver, changes in the expression of components of the avTOR pathway primarily occurred at day 42, and differential gene expression suggests that avTOR complex 1 (avTORC1) affects feed efficiency at day 42. avTORC1 may be activated in the duodenum of feed-efficient birds to increase nutrient mobilization to other peripheral tissues. Furthermore, activation of avTOR in relation to feed efficiency may be tissue specific and may depend on the tissue's need for growth and nutrient transport. Genetic markers in key genes involved in the avTOR/PI3K pathway could be developed to improve feed efficiency in meat-type chickens.

  9. Folic acid inhibits dedifferentiation of PDGF-BB-induced vascular smooth muscle cells by suppressing mTOR/P70S6K signaling.

    Science.gov (United States)

    Pan, Sunlei; Lin, Hui; Luo, Hangqi; Gao, Feidan; Meng, Liping; Zhou, Changzuan; Jiang, Chengjian; Guo, Yan; Ji, Zheng; Chi, Jufang; Guo, Hangyuan

    2017-01-01

    Folic acid (FA) supplementation reduces the risk of atherosclerosis and stroke. Phenotypic change from differentiated to dedifferentiated vascular smooth muscle cells (VSMCs) plays an important role in atherosclerosis development; however, the exact mechanisms remain unknown. This study aimed to assess whether FA through mammalian target of rapamycin (mTOR)/P70S6K signaling inhibits platelet derived growth factor (PDGF-BB) induced VSMC dedifferentiation. VSMCs from primary cultures were identified by morphological observation and α-smooth muscle actin (α-SM-actin, α-SMA) immunocytochemistry. Then, VSMCs were induced by PDGF-BB and treated with varying FA concentrations. Rapamycin and MHY-1485 were used to inhibit or activate the mTOR/P70S6K pathway, respectively. Next, MTT, Transwell, and wound healing assays were employed to assess proliferation and migration of VSMCs. In addition, Western blotting was used to evaluate protein levels of α-SMA, calponin, osteopontin, mTOR, p-mTOR, P70S6K and p-P70S6K in VSMCs. VSMCs showed phenotypic alteration from differentiated to dedifferentiated cells in response to PDGF-BB. MTT, Transwell and wound healing assays showed that FA markedly inhibited proliferation and migration in PDGF-BB-induced VSMCs, in a time and concentration-dependent manner. FA treatment increased the expression levels of the contractile phenotype marker proteins α-SMA and calponin compared with VSMCs stimulated by PDGF-BB alone. Furthermore, FA significantly suppressed mTOR and P70S6K phosphorylation compared with PDGF-BB alone. Similar to FA, downregulation of mTOR signaling by rapamycin inhibited VSMC dedifferentiation. In contrast, upregulation of mTOR signaling by MHY-1485 reversed the FA-induced inhibition of VSMC dedifferentiation. Folic acid inhibits dedifferentiation of PDGF-BB-induced VSMCs by suppressing mTOR/P70S6K signaling.

  10. Inhibition of protein kinase C delta attenuates allergic airway inflammation through suppression of PI3K/Akt/mTOR/HIF-1 alpha/VEGF pathway.

    Directory of Open Access Journals (Sweden)

    Yun Ho Choi

    Full Text Available Vascular endothelial growth factor (VEGF is supposed to contribute to the pathogenesis of allergic airway disease. VEGF expression is regulated by a variety of stimuli such as nitric oxide, growth factors, and hypoxia-inducible factor-1 alpha (HIF-1α. Recently, inhibition of the mammalian target of rapamycin (mTOR has been shown to alleviate cardinal asthmatic features, including airway hyperresponsiveness, eosinophilic inflammation, and increased vascular permeability in asthma models. Based on these observations, we have investigated whether mTOR is associated with HIF-1α-mediated VEGF expression in allergic asthma. In studies with the mTOR inhibitor rapamycin, we have elucidated the stimulatory role of a mTOR-HIF-1α-VEGF axis in allergic response. Next, the mechanisms by which mTOR is activated to modulate this response have been evaluated. mTOR is known to be regulated by phosphoinositide 3-kinase (PI3K/Akt or protein kinase C-delta (PKC δ in various cell types. Consistent with these, our results have revealed that suppression of PKC δ by rottlerin leads to the inhibition of PI3K/Akt activity and the subsequent blockade of a mTOR-HIF-1α-VEGF module, thereby attenuating typical asthmatic attack in a murine model. Thus, the present data indicate that PKC δ is necessary for the modulation of the PI3K/Akt/mTOR signaling cascade, resulting in a tight regulation of HIF-1α activity and VEGF expression. In conclusion, PKC δ may represent a valuable target for innovative therapeutic treatment of allergic airway disease.

  11. Inducible nitric oxide synthase (iNOS) drives mTOR pathway activation and proliferation of human melanoma by reversible nitrosylation of TSC2

    Science.gov (United States)

    Lopez-Rivera, Esther; Jayaraman, Padmini; Parikh, Falguni; Davies, Michael A.; Ekmekcioglu, Suhendan; Izadmehr, Sudeh; Milton, Denái R.; Chipuk, Jerry E.; Grimm, Elizabeth A.; Estrada, Yeriel; Aguirre-Ghiso, Julio; Sikora, Andrew G.

    2014-01-01

    Melanoma is one of the cancers of fastest-rising incidence in the world. iNOS is overexpressed in melanoma and other cancers, and previous data suggest that iNOS and nitric oxide (NO) drive survival and proliferation of human melanoma cells. However, specific mechanisms through which this occurs are poorly defined. One candidate is the PI3K/AKT/mTOR pathway, which plays a major role in proliferation, angiogenesis, and metastasis of melanoma and other cancers. We used the chick embryo chorioallantoic membrane (CAM) assay to test the hypothesis that melanoma growth is regulated by iNOS-dependent mTOR pathway activation. Both pharmacologic inhibition and siRNA-mediated gene silencing of iNOS suppressed melanoma proliferation and in vivo growth on the CAM in human melanoma models. This was associated with strong downregulation of mTOR pathway activation by Western blot analysis of p-mTOR, p-P70S6K, p-S6RP, and p-4EBP1. iNOS expression and NO were associated with reversible nitrosylation of TSC2, and inhibited dimerization of TSC2 with its inhibitory partner TSC1, enhancing GTPase activity of its target Rheb, a critical activator of mTOR signaling. Immunohistochemical analysis of tumor specimens from stage III melanoma patients showed a significant correlation between iNOS expression levels and expression of mTOR pathway members. Exogenously-supplied NO was also sufficient to reverse mTOR pathway inhibition by the B-Raf inhibitor Vemurafenib. In summary, covalent modification of TSC2 by iNOS-derived NO is associated with impaired TSC2/TSC1 dimerization, mTOR pathway activation, and proliferation of human melanoma. This model is consistent with the known association of iNOS overexpression and poor prognosis in melanoma and other cancers. PMID:24398473

  12. The role of diacylglycerol kinase ζ and phosphatidic acid in the mechanical activation of mammalian target of rapamycin (mTOR) signaling and skeletal muscle hypertrophy.

    Science.gov (United States)

    You, Jae-Sung; Lincoln, Hannah C; Kim, Chan-Ran; Frey, John W; Goodman, Craig A; Zhong, Xiao-Ping; Hornberger, Troy A

    2014-01-17

    The activation of mTOR signaling is essential for mechanically induced changes in skeletal muscle mass, and previous studies have suggested that mechanical stimuli activate mTOR (mammalian target of rapamycin) signaling through a phospholipase D (PLD)-dependent increase in the concentration of phosphatidic acid (PA). Consistent with this conclusion, we obtained evidence which further suggests that mechanical stimuli utilize PA as a direct upstream activator of mTOR signaling. Unexpectedly though, we found that the activation of PLD is not necessary for the mechanically induced increases in PA or mTOR signaling. Motivated by this observation, we performed experiments that were aimed at identifying the enzyme(s) that promotes the increase in PA. These experiments revealed that mechanical stimulation increases the concentration of diacylglycerol (DAG) and the activity of DAG kinases (DGKs) in membranous structures. Furthermore, using knock-out mice, we determined that the ζ isoform of DGK (DGKζ) is necessary for the mechanically induced increase in PA. We also determined that DGKζ significantly contributes to the mechanical activation of mTOR signaling, and this is likely driven by an enhanced binding of PA to mTOR. Last, we found that the overexpression of DGKζ is sufficient to induce muscle fiber hypertrophy through an mTOR-dependent mechanism, and this event requires DGKζ kinase activity (i.e. the synthesis of PA). Combined, these results indicate that DGKζ, but not PLD, plays an important role in mechanically induced increases in PA and mTOR signaling. Furthermore, this study suggests that DGKζ could be a fundamental component of the mechanism(s) through which mechanical stimuli regulate skeletal muscle mass.

  13. The Role of Diacylglycerol Kinase ζ and Phosphatidic Acid in the Mechanical Activation of Mammalian Target of Rapamycin (mTOR) Signaling and Skeletal Muscle Hypertrophy*

    Science.gov (United States)

    You, Jae-Sung; Lincoln, Hannah C.; Kim, Chan-Ran; Frey, John W.; Goodman, Craig A.; Zhong, Xiao-Ping; Hornberger, Troy A.

    2014-01-01

    The activation of mTOR signaling is essential for mechanically induced changes in skeletal muscle mass, and previous studies have suggested that mechanical stimuli activate mTOR (mammalian target of rapamycin) signaling through a phospholipase D (PLD)-dependent increase in the concentration of phosphatidic acid (PA). Consistent with this conclusion, we obtained evidence which further suggests that mechanical stimuli utilize PA as a direct upstream activator of mTOR signaling. Unexpectedly though, we found that the activation of PLD is not necessary for the mechanically induced increases in PA or mTOR signaling. Motivated by this observation, we performed experiments that were aimed at identifying the enzyme(s) that promotes the increase in PA. These experiments revealed that mechanical stimulation increases the concentration of diacylglycerol (DAG) and the activity of DAG kinases (DGKs) in membranous structures. Furthermore, using knock-out mice, we determined that the ζ isoform of DGK (DGKζ) is necessary for the mechanically induced increase in PA. We also determined that DGKζ significantly contributes to the mechanical activation of mTOR signaling, and this is likely driven by an enhanced binding of PA to mTOR. Last, we found that the overexpression of DGKζ is sufficient to induce muscle fiber hypertrophy through an mTOR-dependent mechanism, and this event requires DGKζ kinase activity (i.e. the synthesis of PA). Combined, these results indicate that DGKζ, but not PLD, plays an important role in mechanically induced increases in PA and mTOR signaling. Furthermore, this study suggests that DGKζ could be a fundamental component of the mechanism(s) through which mechanical stimuli regulate skeletal muscle mass. PMID:24302719

  14. Different patterns of Akt and ERK feedback activation in response to rapamycin, active-site mTOR inhibitors and metformin in pancreatic cancer cells.

    Science.gov (United States)

    Soares, Heloisa P; Ni, Yang; Kisfalvi, Krisztina; Sinnett-Smith, James; Rozengurt, Enrique

    2013-01-01

    The mTOR pathway is aberrantly stimulated in many cancer cells, including pancreatic ductal adenocarcinoma (PDAC), and thus it is a potential target for therapy. However, the mTORC1/S6K axis also mediates negative feedback loops that attenuate signaling via insulin/IGF receptor and other tyrosine kinase receptors. Suppression of these feed-back loops unleashes over-activation of upstream pathways that potentially counterbalance the antiproliferative effects of mTOR inhibitors. Here, we demonstrate that treatment of PANC-1 or MiaPaCa-2 pancreatic cancer cells with either rapamycin or active-site mTOR inhibitors suppressed S6K and S6 phosphorylation induced by insulin and the GPCR agonist neurotensin. Rapamycin caused a striking increase in Akt phosphorylation at Ser(473) while the active-site inhibitors of mTOR (KU63794 and PP242) completely abrogated Akt phosphorylation at this site. Conversely, active-site inhibitors of mTOR cause a marked increase in ERK activation whereas rapamycin did not have any stimulatory effect on ERK activation. The results imply that first and second generation of mTOR inhibitors promote over-activation of different pro-oncogenic pathways in PDAC cells, suggesting that suppression of feed-back loops should be a major consideration in the use of these inhibitors for PDAC therapy. In contrast, metformin abolished mTORC1 activation without over-stimulating Akt phosphorylation on Ser(473) and prevented mitogen-stimulated ERK activation in PDAC cells. Metformin induced a more pronounced inhibition of proliferation than either KU63794 or rapamycin while, the active-site mTOR inhibitor was more effective than rapamycin. Thus, the effects of metformin on Akt and ERK activation are strikingly different from allosteric or active-site mTOR inhibitors in PDAC cells, though all these agents potently inhibited the mTORC1/S6K axis.

  15. PKI-587 and sorafenib targeting PI3K/AKT/mTOR and Ras/Raf/MAPK pathways synergistically inhibit HCC cell proliferation.

    Science.gov (United States)

    Gedaly, Roberto; Angulo, Paul; Hundley, Jonathan; Daily, Michael F; Chen, Changguo; Evers, B Mark

    2012-08-01

    Deregulated Ras/Raf/MAPK and PI3K/AKT/mTOR signaling pathways are found in hepatocellular carcinoma (HCC). This study aimed to test the inhibitory effects of PKI-587 and sorafenib as single agents or in combination on HCC (Huh7 cell line) proliferation. (3)H-thymidine incorporation and MTT assay were used to assess Huh7 cell proliferation. Phosphorylation of the key enzymes in the Ras/Raf/MAPK and PI3K/AKT/mTOR pathways was detected by Western blot. We found that PKI-587 is a more potent PI3K/mTOR inhibitor than PI-103. Combination of PKI-587 and sorafenib was a more effective inhibitor of Huh7 proliferation than the combination of PI-103 and sorafenib. Combination of PKI-587 and sorafenib synergistically inhibited epidermal growth factor (EGF)-stimulated Huh7 proliferation compared with monodrug therapy. EGF increased phosphorylation of Ras/Raf downstream signaling proteins MEK and ERK; EGF-stimulated activation was inhibited by sorafenib. However, sorafenib, as a single agent, increased AKT (Ser473) phosphorylation. EGF-stimulated AKT (ser473) activation was inhibited by PKI-587. PKI-587 is a potent inhibitor of AKT (Ser473), mTOR (Ser2448), and S6K (Thr389) phosphorylation; in contrast, rapamycin stimulated mTOR complex 2 substrate AKT(Ser473) phosphorylation although it inhibited mTOR complex 1 substrate S6K phosphorylation. PKI-587, as a single agent, stimulated MEK and ERK phosphorylation. However, when PKI-587 and sorafenib were used in combination, they inhibited all the tested kinases in the Ras/Raf /MAPK and PI3K/AKT/mTOR pathways. The combination of PKI-587 and sorafenib has the advantage over monodrug therapy on inhibition of HCC cell proliferation by blocking both PI3K/AKT/mTOR and Ras/Raf/MAPK signaling pathways. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. A subset of metastatic pancreatic ductal adenocarcinomas depends quantitatively on oncogenic Kras/Mek/Erk-induced hyperactive mTOR signalling.

    Science.gov (United States)

    Kong, Bo; Wu, Weiwei; Cheng, Tao; Schlitter, Anna Melissa; Qian, Chengjia; Bruns, Philipp; Jian, Ziying; Jäger, Carsten; Regel, Ivonne; Raulefs, Susanne; Behler, Nora; Irmler, Martin; Beckers, Johannes; Friess, Helmut; Erkan, Mert; Siveke, Jens T; Tannapfel, Andrea; Hahn, Stephan A; Theis, Fabian J; Esposito, Irene; Kleeff, Jörg; Michalski, Christoph W

    2016-04-01

    Oncogenic Kras-activated robust Mek/Erk signals phosphorylate to the tuberous sclerosis complex (Tsc) and deactivates mammalian target of rapamycin (mTOR) suppression in pancreatic ductal adenocarcinoma (PDAC); however, Mek and mTOR inhibitors alone have demonstrated minimal clinical antitumor activity. We generated transgenic mouse models in which mTOR was hyperactivated either through the Kras/Mek/Erk cascade, by loss of Pten or through Tsc1 haploinsufficiency. Primary cancer cells were isolated from mouse tumours. Oncogenic signalling was assessed in vitro and in vivo, with and without single or multiple targeted molecule inhibition. Transcriptional profiling was used to identify biomarkers predictive of the underlying pathway alterations and of therapeutic response. Results from the preclinical models were confirmed on human material. Reduction of Tsc1 function facilitated activation of Kras/Mek/Erk-mediated mTOR signalling, which promoted the development of metastatic PDACs. Single inhibition of mTOR or Mek elicited strong feedback activation of Erk or Akt, respectively. Only dual inhibition of Mek and PI3K reduced mTOR activity and effectively induced cancer cell apoptosis. Analysis of downstream targets demonstrated that oncogenic activity of the Mek/Erk/Tsc/mTOR axis relied on Aldh1a3 function. Moreover, in clinical PDAC samples, ALDH1A3 specifically labelled an aggressive subtype. These results advance our understanding of Mek/Erk-driven mTOR activation and its downstream targets in PDAC, and provide a mechanistic rationale for effective therapeutic matching for Aldh1a3-positive PDACs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  17. Accuracy of magnetic resonance based susceptibility measurements

    Science.gov (United States)

    Erdevig, Hannah E.; Russek, Stephen E.; Carnicka, Slavka; Stupic, Karl F.; Keenan, Kathryn E.

    2017-05-01

    Magnetic Resonance Imaging (MRI) is increasingly used to map the magnetic susceptibility of tissue to identify cerebral microbleeds associated with traumatic brain injury and pathological iron deposits associated with neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Accurate measurements of susceptibility are important for determining oxygen and iron content in blood vessels and brain tissue for use in noninvasive clinical diagnosis and treatment assessments. Induced magnetic fields with amplitude on the order of 100 nT, can be detected using MRI phase images. The induced field distributions can then be inverted to obtain quantitative susceptibility maps. The focus of this research was to determine the accuracy of MRI-based susceptibility measurements using simple phantom geometries and to compare the susceptibility measurements with magnetometry measurements where SI-traceable standards are available. The susceptibilities of paramagnetic salt solutions in cylindrical containers were measured as a function of orientation relative to the static MRI field. The observed induced fields as a function of orientation of the cylinder were in good agreement with simple models. The MRI susceptibility measurements were compared with SQUID magnetometry using NIST-traceable standards. MRI can accurately measure relative magnetic susceptibilities while SQUID magnetometry measures absolute magnetic susceptibility. Given the accuracy of moment measurements of tissue mimicking samples, and the need to look at small differences in tissue properties, the use of existing NIST standard reference materials to calibrate MRI reference structures is problematic and better reference materials are required.

  18. Proteochemometric modeling of HIV protease susceptibility

    National Research Council Canada - National Science Library

    Lapins, Maris; Eklund, Martin; Spjuth, Ola; Prusis, Peteris; Wikberg, Jarl E S

    2008-01-01

    .... Therefore, we used proteochemometrics to model the susceptibility of HIV to protease inhibitors in current use, utilizing descriptions of the physico-chemical properties of mutated HIV proteases...

  19. Insulin promotes glucose consumption via regulation of miR-99a/mTOR/PKM2 pathway.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available Insulin is known to regulate multiple cellular functions and is used for the treatment of diabetes. MicroRNAs have been demonstrated to be involved in many human diseases, including Type 2 diabetes. In this study, we showed that insulin decreased miR-99a expression levels, but induced glucose consumption and lactate production, and increased the expression of mTOR, HIF-1α and PKM2 in HepG2 and HL7702 cells. Forced expression of miR-99a or rapamycin treatment blocked insulin-induced PKM2 and HIF-1α expression, and glucose consumption and lactate production. Meanwhile, knockdown of HIF-1α inhibited PKM2 expression and insulin-induced glucose consumption. Taken together, these findings will reveal the role and mechanism of insulin in regulating glycolytic activities via miR-99a/mTOR.

  20. Dual abrogation of MNK and mTOR: a novel therapeutic approach for the treatment of aggressive cancers.

    Science.gov (United States)

    Lineham, Ella; Spencer, John; Morley, Simon J

    2017-09-01

    Targeting the translational machinery has emerged as a promising therapeutic option for cancer treatment. Cancer cells require elevated protein synthesis and exhibit augmented activity to meet the increased metabolic demand. Eukaryotic translation initiation factor 4E is necessary for mRNA translation, its availability and phosphorylation are regulated by the PI3K/AKT/mTOR and MNK1/2 pathways. The phosphorylated form of eIF4E drives the expression of oncogenic proteins including those involved in metastasis. In this article, we will review the role of eIF4E in cancer, its regulation and discuss the benefit of dual inhibition of upstream pathways. The discernible interplay between the MNK and mTOR signaling pathways provides a novel therapeutic opportunity to target aggressive migratory cancers through the development of hybrid molecules.

  1. Frequent alterations of the PI3K/AKT/mTOR pathways in hereditary nonpolyposis colorectal cancer

    DEFF Research Database (Denmark)

    Jönsson, Mats; Ekstrand, Anna Isinger; Jönsson, Mats

    2010-01-01

    , and PTEN in colorectal cancers linked to hereditary nonpolyposis colorectal cancer (HNPCC). Sequencing was used to identify mutations in PIK3CA, a real-time PCR-based method to identify KRAS mutations, and immunohistochemical staining was used to evaluate the expression of PIK3CA, phosphorylated AKT......The phosphatidylinositol 3-kinases-AKT-mammalian target of rapamycin pathway (PI3K/AKT/mTOR) is central in colorectal tumors. Data on its role in hereditary cancers are, however, scarce and we therefore characterized mutations in PIK3CA and KRAS, and expression of PIK3CA, phosphorylated AKT...... and PTEN in 58 HNPCC-associated colorectal cancers. Derangements of at least one of the PI3K/AKT/mTOR components analyzed were found in 51/58 (88%) tumors. Mutations in PIK3CA and KRAS were identified in 14 and 31% of the tumors respectively. Overexpression of PIK3CA and phosphorylated AKT occurred in 59...

  2. Reparación endovascular torácica aórtica (TEVAR: un enfoque sobre complicaciones

    Directory of Open Access Journals (Sweden)

    Ali Azizzadeh

    2010-01-01

    Full Text Available La reparación endovascular torácica (TEVAR se ha constituido como una alternativa válida para la reparación de los aneurismas torácicos, al ser menos agresiva. Una reciente revisión sistemática y metaanálisis de estudios comparativos confirma que TEVAR, cuando se compara con la cirugía abierta, puede reducir la muerte precoz, la paraplejía, insuficiencia renal, transfusiones, reoperación por hemorragia, complicaciones cardíacas, neumonía y estancia hospitalaria. Esta revisión se referirá a algunas de las complicaciones del procedimiento. Éstas incluyen: mortalidad, accidente cerebrovascular, isquemia medular, disección retrógrada, disfunción del dispositivo, complicaciones del acceso, endofuga y migración.

  3. Ion torrent next-generation sequencing reveals the complete mitochondrial genome of endangered mahseer Tor khudree (Sykes, 1839).

    Science.gov (United States)

    Raman, Sudhanshu; Pavan-Kumar, A; Koringa, Prakash G; Patel, Namrata; Shah, Tejas; Singh, Rajeev K; Krishna, Gopal; Joshi, C G; Gireesh-Babu, P; Chaudhari, Aparna; Lakra, W S

    2016-07-01

    The complete mitochondrial genome of an endangered mahseer (Deccan mahseer), Tor khudree was sequenced using Ion torrent platform for the first time. The genome sequence was 16 573 bp in size, and consists of 13 protein coding genes, 22 tRNAs, 2 rRNA genes and 1 control region. The gene organization and its order were similar to other vertebrates. The overall base composition was A: 31.9%, G: 15.6%, C: 27.68%, T: 24.76%, A + T content 56.6% and the G + C content 43.32%. The phylogenetic tree constructed using a maximum likelihood model showed sister relationship between T. khudree and Tor tambroides.

  4. Pathway interactions between MAPKs, mTOR, PKA, and the glucocorticoid receptor in lymphoid cells

    Directory of Open Access Journals (Sweden)

    Thompson E Brad

    2007-03-01

    Full Text Available Abstract Background Glucocorticoids are frequently used as a primary chemotherapeutic agent in many types of human lymphoid malignancies because they induce apoptosis through activation of the glucocorticoid receptor, with subsequent alteration of a complex network of cellular mechanisms. Despite clinical usage for over fifty years, the complete mechanism responsible for glucocorticoid-related apoptosis or resistance remains elusive. The mitogen-activated protein kinase pathway is a signal transduction network that influences a variety of cellular responses through phosphorylation of specific target substrates, including the glucocorticoid receptor. In this study we have evaluated the pharmaceutical scenarios which converge on the mitogen-activated protein kinase pathway to alter glucocorticoid sensitivity in clones of human acute lymphoblastic CEM cells sensitive and refractory to apoptosis in response to the synthetic glucocorticoid dexamethasone. Results The glucocorticoid-resistant clone CEM-C1-15 displays a combination of high constitutive JNK activity and dexamethasone-induced ERK activity with a weak induction of p38 upon glucocorticoid treatment. The cells become sensitive to glucocorticoid-evoked apoptosis after: (1 inhibition of JNK and ERK activity, (2 stimulation of the cAMP/PKA pathway with forskolin, or (3 inhibition of mTOR with rapamycin. Treatments 1–3 in combination with dexamethasone alter the intracellular balance of phospho-MAPKs by lowering JNK phosphorylation and increasing the level of glucocorticoid receptor phosphorylated at serine 211, a modification known to enhance receptor activity. Conclusion Our data support the hypothesis that mitogen-activated protein kinases influence the ability of certain malignant lymphoid cells to undergo apoptosis when treated with glucocorticoid. Activated/phosphorylated JNK and ERK appear to counteract corticoid-dependent apoptosis. Inhibiting these MAPKs restores corticoid sensitivity

  5. Dihydroartemisinin potentiates the anticancer effect of cisplatin via mTOR inhibition in cisplatin-resistant ovarian cancer cells: involvement of apoptosis and autophagy

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xue [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Li, Ling [Department of Brain Cognition Computing Lab, University of Kent, Kent CT2 7NZ (United Kingdom); Jiang, Hong; Jiang, Keping; Jin, Ye [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China); Zheng, Jianhua, E-mail: zhengjianhua1115@126.com [Department of Gynecology and Obstetrics, The First Affiliated Hospital of Harbin Medical University, Harbin 150001 (China)

    2014-02-14

    Highlights: • Phosphorylation of mTOR is abnormal activation in SKOV3/DDP ovarian cancer cells. • Downregulation of mTOR by DHA helps to sensitize the SKOV3/DDP cells to chemotherapy. • DHA has the potential of induce autophagy in cancer cells. - Abstract: Dihydroartemisinin (DHA) exhibits anticancer activity in tumor cells but its mechanism of action is unclear. Cisplatin (DDP) is currently the best known chemotherapeutic available for ovarian cancer. However, tumors return de novo with acquired resistance over time. Mammalian target of rapamycin (mTOR) is an important kinase that regulates cell apoptosis and autophagy, and its dysregulation has been observed in chemoresistant human cancers. Here, we show that compared with control ovarian cancer cells (SKOV3), mTOR phosphorylation was abnormally activated in cisplatin-resistant ovarian cancer cells (SKOV3/DDP) following cisplatin monotherapy. Treatment with cisplatin combined with DHA could enhance cisplatin-induced proliferation inhibition in SKOV3/DDP cells. This mechanism is at least partially due to DHA deactivation of mTOR kinase and promotion of apoptosis. Although autophagy was also induced by DHA, the reduced cell death was not found by suppressing autophagic flux by Bafilomycin A1 (BAF). Taken together, we conclude that inhibition of cisplatin-induced mTOR activation is one of the main mechanisms by which DHA dramatically promotes its anticancer effect in cisplatin-resistant ovarian cancer cells.

  6. The Regulation of Lipid Deposition by Insulin in Goose Liver Cells Is Mediated by the PI3K-AKT-mTOR Signaling Pathway.

    Science.gov (United States)

    Han, Chunchun; Wei, Shouhai; He, Fang; Liu, Dandan; Wan, Huofu; Liu, Hehe; Li, Liang; Xu, Hongyong; Du, Xiaohui; Xu, Feng

    2015-01-01

    We previously showed that the fatty liver formations observed in overfed geese are accompanied by the activation of the PI3K-Akt-mTOR pathway and an increase in plasma insulin concentrations. Recent studies have suggested a crucial role for the PI3K-Akt-mTOR pathway in regulating lipid metabolism; therefore, we hypothesized that insulin affects goose hepatocellular lipid metabolism through the PI3K-Akt-mTOR signaling pathway. Goose primary hepatocytes were isolated and treated with serum-free media supplemented with PI3K-Akt-mTOR pathway inhibitors (LY294002, rapamycin, and NVP-BEZ235, respectively) and 50 or 150 nmol/L insulin. Insulin induced strong effects on lipid accumulation as well as the mRNA and protein levels of genes involved in lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in primary goose hepatocytes. The stimulatory effect of insulin on lipogenesis was significantly decreased by treatment with PI3K-Akt-mTOR inhibitors. These inhibitors also rescued the insulin-induced down-regulation of fatty acid oxidation and VLDL-TG assembly and secretion. These findings suggest that the stimulatory effect of insulin on lipid deposition is mediated by PI3K-Akt-mTOR regulation of lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in goose hepatocytes.

  7. The Regulation of Lipid Deposition by Insulin in Goose Liver Cells Is Mediated by the PI3K-AKT-mTOR Signaling Pathway.

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    Chunchun Han

    Full Text Available We previously showed that the fatty liver formations observed in overfed geese are accompanied by the activation of the PI3K-Akt-mTOR pathway and an increase in plasma insulin concentrations. Recent studies have suggested a crucial role for the PI3K-Akt-mTOR pathway in regulating lipid metabolism; therefore, we hypothesized that insulin affects goose hepatocellular lipid metabolism through the PI3K-Akt-mTOR signaling pathway.Goose primary hepatocytes were isolated and treated with serum-free media supplemented with PI3K-Akt-mTOR pathway inhibitors (LY294002, rapamycin, and NVP-BEZ235, respectively and 50 or 150 nmol/L insulin.Insulin induced strong effects on lipid accumulation as well as the mRNA and protein levels of genes involved in lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in primary goose hepatocytes. The stimulatory effect of insulin on lipogenesis was significantly decreased by treatment with PI3K-Akt-mTOR inhibitors. These inhibitors also rescued the insulin-induced down-regulation of fatty acid oxidation and VLDL-TG assembly and secretion.These findings suggest that the stimulatory effect of insulin on lipid deposition is mediated by PI3K-Akt-mTOR regulation of lipogenesis, fatty acid oxidation, and VLDL-TG assembly and secretion in goose hepatocytes.

  8. Glucose-induced lipid deposition in goose primary hepatocytes is dependent on the PI3K-Akt-mTOR signaling pathway

    Directory of Open Access Journals (Sweden)

    Han Chunchun

    2016-01-01

    Full Text Available Previously we showed that fatty liver formation in overfed geese was accompanied by PI3K-Akt-mTOR pathway activation and changes in plasma glucose concentrations. Here, we show that glucose acts in goose hepatocellular lipid metabolism through the PI3K-Akt-mTOR signaling pathway. We observed that glucose increased lipogenesis, decreased fatty acid oxidation and increased very low density lipoprotein triglyceride (VLDL-TG assembly and secretion. Co-treatment with glucose and inhibitors of the PI3K-Akt-mTOR pathway (LY294002, rapamycin, NVP-BEZ235 decreased the levels of factors involved in lipogenesis and increased the levels of factors involved in fatty acid oxidation and VLDL-TG assembly and secretion. These findings show that inhibition of the PI3K-Akt-mTOR pathway decreased glucose-induced lipogenesis, inhibited the downregulation of fatty acid oxidation by glucose and increased the upregulation of VLDL-TG assembly and secretion by glucose. The results presented herein provide further support for the role of the PI3K-Akt-mTOR pathway in lipid metabolism as we showed that in goose primary hepatocytes, glucose acts through the PI3K-Akt-mTOR-dependent pathway to stimulate lipid deposition by increasing lipogenesis and decreasing fatty acid oxidation and VLDL-TG assembly and secretion.

  9. Immunohistochemical Analysis of the Activation Status of the Akt/mTOR/pS6 Signaling Pathway in Oral Lichen Planus

    Directory of Open Access Journals (Sweden)

    Georgios Prodromidis

    2013-01-01

    Full Text Available Introduction. Aberrations of the Akt/mTOR/pS6 pathway have been