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Sample records for cellular regulators part

  1. Regulation of cellular chromatin state

    PubMed Central

    Mishra, Rakesh K; Dhawan, Jyotsna

    2010-01-01

    The identity and functionality of eukaryotic cells is defined not just by their genomic sequence which remains constant between cell types, but by their gene expression profiles governed by epigenetic mechanisms. Epigenetic controls maintain and change the chromatin state throughout development, as exemplified by the setting up of cellular memory for the regulation and maintenance of homeotic genes in proliferating progenitors during embryonic development. Higher order chromatin structure in reversibly arrested adult stem cells also involves epigenetic regulation and in this review we highlight common trends governing chromatin states, focusing on quiescence and differentiation during myogenesis. Together, these diverse developmental modules reveal the dynamic nature of chromatin regulation providing fresh insights into the role of epigenetic mechanisms in potentiating development and differentiation. PMID:20592864

  2. Klotho-Dependent Cellular Transport Regulation.

    PubMed

    Sopjani, M; Dërmaku-Sopjani, M

    2016-01-01

    Klotho is a transmembrane protein that in humans is encoded by the hKL gene. This protein is known to have aging suppressor effects and is predominantly expressed in the distal convoluted tubule of the kidney, parathyroid glands, and choroid plexus of the brain. The Klotho protein exists in both full-length membrane form and a soluble secreted form, which exerts numerous distinct functions. The extracellular domain of Klotho can be enzymatically cleaved off and released into the systemic circulation where it functions as β-glucuronidase and a hormone. Soluble Klotho is a multifunction protein present in the biological fluids including blood, urine, and cerebrospinal fluid of mammals. Klotho deficiency leads to multiple organ failure accompanied by early appearance of multiple age-related disorders and early death, whereas overexpression of Klotho results in the opposite effects. Klotho, an enzyme and hormone, has been reported to participate in the regulation of cellular transport processes across the plasma membrane either indirectly through inhibiting calcitriol (1,25(OH)2D3) formation or other mechanism, or by directly affecting transporter proteins, including ion channels, cellular carriers, and Na(+)/K(+)-ATPase. Accordingly, Klotho protein serves as a powerful regulator of cellular transport across the plasma membrane. Importantly, Klotho-dependent cellular transport regulation implies stimulatory or inhibitory effects. Klotho has been shown to play a key role in the regulation of multiple calcium and potassium ion channels, and various cellular carriers including the Na(+)-coupled cotransporters such as NaPi-IIa, NaPi-IIb, EAAT3, and EAAT4, CreaT1 as well as Na(+)/K(+)-ATPase. These regulations are parts of the antiaging function of Klotho, which will be discussing throughout this chapter. Clearly, further experimental efforts are required to investigate the effect of Klotho on other transport proteins and underlying molecular mechanisms by which Klotho

  3. Cellular regulation by protein phosphorylation.

    PubMed

    Fischer, Edmond H

    2013-01-11

    A historical account of the discovery of reversible protein phosphorylation is presented. This process was uncovered in the mid 1950s in a study undertaken with Edwin G. Krebs to elucidate the complex hormonal regulation of skeletal muscle glycogen phosphorylase. Contrary to the known activation of this enzyme by AMP which serves as an allosteric effector, its hormonal regulation results from a phosphorylation of the protein by phosphorylase kinase following the activation of the latter by Ca(2+) and ATP. The study led to the establishment of the first hormonal cascade of successive enzymatic reactions, kinases acting on kinases, initiated by cAMP discovered by Earl Sutherland. It also showed how two different physiological processes, carbohydrate metabolism and muscle contraction, could be regulated in concert. PMID:23058924

  4. The cellular basis of aqueous outflow regulation.

    PubMed

    Francis, B A; Alvarado, J

    1997-04-01

    This review begins with an introduction to the concept of the cellular regulation of aqueous outflow, current methods used for its study, and the cell types that are known to participate in this process. Current research in the field is divided into work on cell properties, cell products and extracellular matrix, cytoskeletal and structural changes, and drug interactions. PMID:10168352

  5. Immunometabolism: Cellular Metabolism Turns Immune Regulator.

    PubMed

    Loftus, Róisín M; Finlay, David K

    2016-01-01

    Immune cells are highly dynamic in terms of their growth, proliferation, and effector functions as they respond to immunological challenges. Different immune cells can adopt distinct metabolic configurations that allow the cell to balance its requirements for energy, molecular biosynthesis, and longevity. However, in addition to facilitating immune cell responses, it is now becoming clear that cellular metabolism has direct roles in regulating immune cell function. This review article describes the distinct metabolic signatures of key immune cells, explains how these metabolic setups facilitate immune function, and discusses the emerging evidence that intracellular metabolism has an integral role in controlling immune responses. PMID:26534957

  6. Sialidases as regulators of bioengineered cellular surfaces

    PubMed Central

    Zamora, Cristina Y; Ryan, Matthew J; d'Alarcao, Marc; Kumar, Krishna

    2015-01-01

    Human sialidases (NEUs) catalyze the removal of N-acetyl neuraminic acids from the glycome of the cell and regulate a diverse repertoire of nominal cellular functions, such as cell signaling and adhesion. A greater understanding of their substrate permissivity is of interest in order to discern their physiological functions in disease states and in the design of specific and effective small molecule inhibitors. Towards this, we have synthesized soluble fluorogenic reporters of mammalian sialidase activity bearing unnatural sialic acids commonly incorporated into the cellular glycocalyx via metabolic glycoengineering. We found cell-surface sialidases in Jurkat capable of cleaving unnatural sialic acids with differential activities toward a variety of R groups on neuraminic acid. In addition, we observed modulated structure–activity relationships when cell-surface sialidases were presented glycans with unnatural bulky, hydrophobic or fluorinated moieties incorporated directly via glycoengineering. Our results confirm the importance of cell-surface sialidases in glycoengineering incorporation data. We demonstrate the flexibility of human NEUs toward derivatized sugars and highlight the importance of native glycan presentation to sialidase binding and activity. These results stand to inform not only metabolic glycoengineering efforts but also inhibitor design. PMID:25795684

  7. Regulation of autophagy in oxygen-dependent cellular stress.

    PubMed

    Ryter, Stefan W; Choi, Augustine M K

    2013-01-01

    Oxidative stress caused by supraphysiological production of reactive oxygen species (ROS), can cause cellular injury associated with protein and lipid oxidation, DNA damage, and mitochondrial dysfunction. The cellular responses triggered by oxidative stress include the altered regulation of signaling pathways that culminate in the regulation of cell survival or cell death pathways. Recent studies suggest that autophagy, a cellular homeostatic process that governs the turnover of damaged organelles and proteins, may represent a general cellular and tissue response to oxidative stress. The autophagic pathway involves the encapsulation of substrates in double-membraned vesicles, which are subsequently delivered to the lysosome for enzymatic degradation and recycling of metabolic precursors. Autophagy may play multifunctional roles in cellular adaptation to stress, by maintaining mitochondrial integrity, and removing damaged proteins. Additionally, autophagy may play important roles in the regulation of inflammation and immune function. Modulation of the autophagic pathway has been reported in cell culture models of oxidative stress, including altered states of oxygen tension (i.e., hypoxia, hyperoxia), and exposure to oxidants. Furthermore, proteins that regulate autophagy may be subject to redox regulation. The heme oxygenase- 1 (HO)-1 enzyme system may have a role in the regulation of autophagy. Recent studies suggest that carbon monoxide (CO), a reaction product of HO activity which can alter mitochondrial function, may induce autophagy in cultured epithelial cells. In conclusion, current research suggests a central role for autophagy as a mammalian oxidative stress response and its interrelationship to other stress defense systems. PMID:23092322

  8. From syncitium to regulated pump: a cardiac muscle cellular update

    PubMed Central

    2011-01-01

    The primary purpose of this article is to present a basic overview of some key teaching concepts that should be considered for inclusion in an six- to eight-lecture introductory block on the regulation of cardiac performance for graduate students. Within the context of cardiac excitation-contraction coupling, this review incorporates information on Ca2+ microdomains and local control theory, with particular emphasis on the role of Ca2+ sparks as a key regulatory component of ventricular myocyte contraction dynamics. Recent information pertaining to local Ca2+ cycling in sinoatrial nodal cells (SANCs) as a mechanism underlying cardiac automaticity is also presented as part of the recently described coupled-clock pacemaker system. The details of this regulation are emerging; however, the notion that the sequestration and release of Ca2+ from internal stores in SANCs (similar to that observed in ventricular myocytes) regulates the rhythmic excitation of the heart (i.e., membrane ion channels) is an important advancement in this area. The regulatory role of cardiac adrenergic receptors on cardiac rate and function is also included, and fundamental concepts related to intracellular signaling are discussed. An important point of emphasis is that whole organ cardiac dynamics can be traced back to cellular events regulating intracellular Ca2+ homeostasis and, as such, provides an important conceptual framework from which students can begin to think about whole organ physiology in health and disease. Greater synchrony of Ca2+-regulatory mechanisms between ventricular and pacemaker cells should enhance student comprehension of complex regulatory phenomenon in cardiac muscle. PMID:21385997

  9. Regulation of cellular differentiation in Caulobacter crescentus.

    PubMed Central

    Gober, J W; Marques, M V

    1995-01-01

    In Caulobacter crescentus, asymmetry is generated in the predivisional cell, resulting in the formation of two distinct cell types upon cell division: a motile swarmer cell and a sessile stalked cell. These progeny cell types differ in their relative programs of gene expression and DNA replication. In progeny swarmer cells, DNA replication is silenced for a defined period, but stalked cells reinitiate chromosomal DNA replication immediately following cell division. The establishment of these differential programs of DNA replication may be due to the polar localization of DNA replication proteins, differences in chromosome higher-order structure, or pole-specific transcription. The best-understood aspect of Caulobacter development is biogenesis of the polar flagellum. The genes encoding the flagellum are expressed under cell cycle control predominantly in the predivisional cell type. Transcription of flagellar genes is regulated by a trans-acting hierarchy that responds to both flagellar assembly and cell cycle cues. As the flagellar genes are expressed, their products are targeted to the swarmer pole of the predivisional cell, where assembly occurs. Specific protein targeting and compartmentalized transcription are two mechanisms that contribute to the positioning of flagellar gene products at the swarmer pole of the predivisional cell. PMID:7708011

  10. Cellular Pressure and Volume Regulation and Implications for Cell Mechanics

    PubMed Central

    Jiang, Hongyuan; Sun, Sean X.

    2013-01-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it predicts cellular volume and pressure for several models of cell cortical mechanics. Moreover, we show that when cells are subjected to an externally applied load, such as in an atomic force microscopy indentation experiment, active regulation of volume and pressure leads to a complex cellular response. Instead of the passive mechanics of the cortex, the observed cell stiffness depends on several factors working together. This provides a mathematical explanation of rate-dependent response of cells under force. PMID:23931309

  11. Cellular pressure and volume regulation and implications for cell mechanics.

    PubMed

    Jiang, Hongyuan; Sun, Sean X

    2013-08-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death, and migration. Volume and shape regulation also directly impacts the mechanics of cells and tissues. Here, we develop a mathematical model of cellular volume and pressure regulation, incorporating essential elements such as water permeation, mechanosensitive channels, active ion pumps, and active stresses in the cortex. The model can fully explain recent experimental data, and it predicts cellular volume and pressure for several models of cell cortical mechanics. Moreover, we show that when cells are subjected to an externally applied load, such as in an atomic force microscopy indentation experiment, active regulation of volume and pressure leads to a complex cellular response. Instead of the passive mechanics of the cortex, the observed cell stiffness depends on several factors working together. This provides a mathematical explanation of rate-dependent response of cells under force. PMID:23931309

  12. Piezo Proteins: Regulators of Mechanosensation and Other Cellular Processes*

    PubMed Central

    Bagriantsev, Sviatoslav N.; Gracheva, Elena O.; Gallagher, Patrick G.

    2014-01-01

    Piezo proteins have recently been identified as ion channels mediating mechanosensory transduction in mammalian cells. Characterization of these channels has yielded important insights into mechanisms of somatosensation, as well as other mechano-associated biologic processes such as sensing of shear stress, particularly in the vasculature, and regulation of urine flow and bladder distention. Other roles for Piezo proteins have emerged, some unexpected, including participation in cellular development, volume regulation, cellular migration, proliferation, and elongation. Mutations in human Piezo proteins have been associated with a variety of disorders including hereditary xerocytosis and several syndromes with muscular contracture as a prominent feature. PMID:25305018

  13. Regulation of cellular actin architecture by S100A10.

    PubMed

    Jung, M Juliane; Murzik, Ulrike; Wehder, Liane; Hemmerich, Peter; Melle, Christian

    2010-04-15

    Actin structures are involved in several biological processes and the disruption of actin polymerisation induces impaired motility of eukaryotic cells. Different factors are involved in regulation and maintenance of the cytoskeletal actin architecture. Here we show that S100A10 participates in the particular organisation of actin filaments. Down-regulation of S100A10 by specific siRNA triggered a disorganisation of filamentous actin structures without a reduction of the total cellular actin concentration. In contrast, the formation of cytoskeleton structures containing tubulin was unhindered in S100A10 depleted cells. Interestingly, the cellular distribution of annexin A2, an interaction partner of S100A10, was unaffected in S100A10 depleted cells. Cells lacking S100A10 showed an impaired migration activity and were unable to close a scratched wound. Our data provide first insights of S100A10 function as a regulator of the filamentous actin network. PMID:20100475

  14. Cellular pressure and volume regulation and implications for cell mechanics

    NASA Astrophysics Data System (ADS)

    Jiang, Hongyuan; Sun, Sean

    2013-03-01

    In eukaryotic cells, small changes in cell volume can serve as important signals for cell proliferation, death and migration. Volume and shape regulation also directly impacts the mechanics of the cell and multi-cellular tissues. Recent experiments found that during mitosis, eukaryotic cells establish a preferred steady volume and pressure, and the steady volume and pressure can robustly adapt to large osmotic shocks. Here we develop a mathematical model of cellular pressure and volume regulation, incorporating essential elements such as water permeation, mechano-sensitive channels, active ion pumps and active stresses in the actomyosin cortex. The model can fully explain the available experimental data, and predicts the cellular volume and pressure for several models of cell cortical mechanics. Furthermore, we show that when cells are subjected to an externally applied load, such as in an AFM indentation experiment, active regulation of volume and pressure leads to complex cellular response. We found the cell stiffness highly depends on the loading rate, which indicates the transport of water and ions might contribute to the observed viscoelasticity of cells.

  15. Regulation of cardiac cellular bioenergetics: mechanisms and consequences

    PubMed Central

    Tran, Kenneth; Loiselle, Denis S; Crampin, Edmund J

    2015-01-01

    The regulation of cardiac cellular bioenergetics is critical for maintaining normal cell function, yet the nature of this regulation is not fully understood. Different mechanisms have been proposed to explain how mitochondrial ATP production is regulated to match changing cellular energy demand while metabolite concentrations are maintained. We have developed an integrated mathematical model of cardiac cellular bioenergetics, electrophysiology, and mechanics to test whether stimulation of the dehydrogenase flux by Ca2+ or Pi, or stimulation of complex III by Pi can increase the rate of mitochondrial ATP production above that determined by substrate availability (ADP and Pi). Using the model, we show that, under physiological conditions the rate of mitochondrial ATP production can match varying demand through substrate availability alone; that ATP production rate is not limited by the supply of reducing equivalents in the form of NADH, as a result of Ca2+ or Pi activation of the dehydrogenases; and that ATP production rate is sensitive to feedback activation of complex III by Pi. We then investigate the mechanistic implications on cytosolic ion homeostasis and force production by simulating the concentrations of cytosolic Ca2+, Na+ and K+, and activity of the key ATPases, SERCA pump, Na+/K+ pump and actin-myosin ATPase, in response to increasing cellular energy demand. We find that feedback regulation of mitochondrial complex III by Pi improves the coupling between energy demand and mitochondrial ATP production and stabilizes cytosolic ADP and Pi concentrations. This subsequently leads to stabilized cytosolic ionic concentrations and consequentially reduced energetic cost from cellular ATPases. PMID:26229005

  16. Torsins Are Essential Regulators of Cellular Lipid Metabolism.

    PubMed

    Grillet, Micheline; Dominguez Gonzalez, Beatriz; Sicart, Adria; Pöttler, Maria; Cascalho, Ana; Billion, Karolien; Hernandez Diaz, Sergio; Swerts, Jef; Naismith, Teresa V; Gounko, Natalia V; Verstreken, Patrik; Hanson, Phyllis I; Goodchild, Rose E

    2016-08-01

    Torsins are developmentally essential AAA+ proteins, and mutation of human torsinA causes the neurological disease DYT1 dystonia. They localize in the ER membranes, but their cellular function remains unclear. We now show that dTorsin is required in Drosophila adipose tissue, where it suppresses triglyceride levels, promotes cell growth, and elevates membrane lipid content. We also see that human torsinA at the inner nuclear membrane is associated with membrane expansion and elevated cellular lipid content. Furthermore, the key lipid metabolizing enzyme, lipin, is mislocalized in dTorsin-KO cells, and dTorsin increases levels of the lipin substrate, phosphatidate, and reduces the product, diacylglycerol. Finally, genetic suppression of dLipin rescues dTorsin-KO defects, including adipose cell size, animal growth, and survival. These findings identify that torsins are essential regulators of cellular lipid metabolism and implicate disturbed lipid biology in childhood-onset DYT1 dystonia. PMID:27453503

  17. Role of intracellular calcium in cellular volume regulation

    SciTech Connect

    Wong, S.M.; Chase, H.S. Jr.

    1986-06-01

    We investigated the role of intracellular calcium in epithelial cell volume regulation using cells isolated from the toad urinary bladder. A suspension of cells was prepared by treatment of the bladder with collagenase followed by ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid. The cells retained their ion-transporting capabilities: ouabain (1 mM) and amiloride (10 microM) inhibited cellular uptake of /sup 86/Rb and /sup 22/Na, respectively. Using a Coulter counter to measure cellular volume, we found that we could swell cells either by reducing the extracellular osmolality or by adding the permeant solute urea (45 mM) isosmotically. Under both conditions, cells first swelled and then returned to their base-line volume, in spite of the continued presence of the stimulus to swell. Volume regulation was inhibited when cells were swelled at low extracellular (Ca) (100 nM) and was retarded in cells preloaded with the calcium buffer quin 2. Swelling increased the intracellular free calcium concentration ((Ca)i), as measured by quin 2 fluorescence: (Ca)i increased 35 +/- 9 nM (n = 6) after hypotonic swelling and 42 +/- 3 nM (n = 3) after urea swelling. Reducing extracellular (Ca) to less than 100 nM prevented the swelling-induced increase in (Ca)i, suggesting that the source of the increase in (Ca)i was extracellular. This result was confirmed in measurements of cellular uptake of 45Ca: the rate of uptake was significantly higher in swollen cells compared with control (1.1 +/- 0.2 vs. 0.4 +/- 0.1 fmol . cell-1 X 5 min-1). Our experiments provide the first demonstration that cellular swelling increases (Ca)i. This increase is likely to play a critical role in cellular volume regulation.

  18. Cellular Regulation of the Uterine Microenvironment That Enables Embryo Implantation.

    PubMed

    Zenclussen, Ana Claudia; Hämmerling, Günter J

    2015-01-01

    Implantation of the fertilized egg into the maternal uterus is a crucial step in pregnancy establishment. Increasing evidence suggests that its success depends on various cell types of the innate immune system and on the fine balance between inflammatory and anti-inflammatory processes. In addition, it has recently been established that regulatory T cells play a superordinate role in dictating the quality of uterine environment required for successful pregnancy. Here, we discuss the cellular regulation of uterine receptivity with emphasis on the function and regulation of cells from the innate and adaptive immune system. PMID:26136750

  19. Regulating the cellular economy of supply and demand.

    PubMed

    Hofmeyr, J S; Cornish-Bowden, A

    2000-06-30

    Cellular metabolism is a molecular economy that is functionally organised into supply and demand blocks linked by metabolic products and cofactor cycles. Supply-demand analysis allows the behaviour, control and regulation of metabolism as a whole to be understood quantitatively in terms of the elasticities of supply and demand, which are experimentally measurable properties of the individual blocks. The kinetic and thermodynamic aspects of regulation are clearly distinguished. One important result is the demonstration that when flux is controlled by one block, the other block determines to which degree the concentration of the linking metabolite is homeostatically maintained. PMID:10878248

  20. Cellular Regulation of the Uterine Microenvironment That Enables Embryo Implantation

    PubMed Central

    Zenclussen, Ana Claudia; Hämmerling, Günter J.

    2015-01-01

    Implantation of the fertilized egg into the maternal uterus is a crucial step in pregnancy establishment. Increasing evidence suggests that its success depends on various cell types of the innate immune system and on the fine balance between inflammatory and anti-inflammatory processes. In addition, it has recently been established that regulatory T cells play a superordinate role in dictating the quality of uterine environment required for successful pregnancy. Here, we discuss the cellular regulation of uterine receptivity with emphasis on the function and regulation of cells from the innate and adaptive immune system. PMID:26136750

  1. Daily magnesium fluxes regulate cellular timekeeping and energy balance.

    PubMed

    Feeney, Kevin A; Hansen, Louise L; Putker, Marrit; Olivares-Yañez, Consuelo; Day, Jason; Eades, Lorna J; Larrondo, Luis F; Hoyle, Nathaniel P; O'Neill, John S; van Ooijen, Gerben

    2016-04-21

    Circadian clocks are fundamental to the biology of most eukaryotes, coordinating behaviour and physiology to resonate with the environmental cycle of day and night through complex networks of clock-controlled genes. A fundamental knowledge gap exists, however, between circadian gene expression cycles and the biochemical mechanisms that ultimately facilitate circadian regulation of cell biology. Here we report circadian rhythms in the intracellular concentration of magnesium ions, [Mg(2+)]i, which act as a cell-autonomous timekeeping component to determine key clock properties both in a human cell line and in a unicellular alga that diverged from each other more than 1 billion years ago. Given the essential role of Mg(2+) as a cofactor for ATP, a functional consequence of [Mg(2+)]i oscillations is dynamic regulation of cellular energy expenditure over the daily cycle. Mechanistically, we find that these rhythms provide bilateral feedback linking rhythmic metabolism to clock-controlled gene expression. The global regulation of nucleotide triphosphate turnover by intracellular Mg(2+) availability has potential to impact upon many of the cell's more than 600 MgATP-dependent enzymes and every cellular system where MgNTP hydrolysis becomes rate limiting. Indeed, we find that circadian control of translation by mTOR is regulated through [Mg(2+)]i oscillations. It will now be important to identify which additional biological processes are subject to this form of regulation in tissues of multicellular organisms such as plants and humans, in the context of health and disease. PMID:27074515

  2. tRNA modifications regulate translation during cellular stress

    PubMed Central

    Gu, Chen; Begley, Thomas J.; Dedon, Peter C.

    2014-01-01

    The regulation of gene expression in response to stress is an essential cellular protection mechanism. Recent advances in tRNA modification analysis and genome-based codon bias analytics have facilitated studies that lead to a novel model for translational control, with translation elongation dynamically regulated during stress responses. Stress-induced increases in specific anticodon wobble bases are required for the optimal translation of stress response transcripts that are significantly biased in the use of degenerate codons keyed to these modified tRNA bases. These findings led us to introduce the notion of tRNA modification tunable transcripts (MoTTs – transcripts whose translation is regulated by tRNA modifications), which are identifiable using genome-wide codon counting algorithms. In support of this general model of translational control of stress response, studies making use of detailed measures of translation, tRNA methyltransferase mutants, and computational and mass spectrometry approaches reveal that stress reprograms tRNA modifications to translationally regulate MoTTs linked to arginine and leucine codons, which helps cells survive insults by damaging agents. These studies highlight how tRNA methyltransferase activities and MoTTs are key components of the cellular stress response. PMID:25304425

  3. Neurophysiology of HCN channels: from cellular functions to multiple regulations.

    PubMed

    He, Chao; Chen, Fang; Li, Bo; Hu, Zhian

    2014-01-01

    Hyperpolarization-activated cyclic nucleotide-gated (HCN) cation channels are encoded by HCN1-4 gene family and have four subtypes. These channels are activated upon hyperpolarization of membrane potential and conduct an inward, excitatory current Ih in the nervous system. Ih acts as pacemaker current to initiate rhythmic firing, dampen dendritic excitability and regulate presynaptic neurotransmitter release. This review summarizes recent insights into the cellular functions of Ih and associated behavior such as learning and memory, sleep and arousal. HCN channels are excellent targets of various cellular signals to finely regulate neuronal responses to external stimuli. Numerous mechanisms, including transcriptional control, trafficking, as well as channel assembly and modification, underlie HCN channel regulation. In the next section, we discuss how the intracellular signals, especially recent findings concerning protein kinases and interacting proteins such as cGKII, Ca(2+)/CaMKII and TRIP8b, regulate function and expression of HCN channels, and subsequently provide an overview of the effects of neurotransmitters on HCN channels and their corresponding intracellular mechanisms. We also discuss the dysregulation of HCN channels in pathological conditions. Finally, insight into future directions in this exciting area of ion channel research is provided. PMID:24184323

  4. Complement-Mediated Regulation of Metabolism and Basic Cellular Processes.

    PubMed

    Hess, Christoph; Kemper, Claudia

    2016-08-16

    Complement is well appreciated as a critical arm of innate immunity. It is required for the removal of invading pathogens and works by directly destroying them through the activation of innate and adaptive immune cells. However, complement activation and function is not confined to the extracellular space but also occurs within cells. Recent work indicates that complement activation regulates key metabolic pathways and thus can impact fundamental cellular processes, such as survival, proliferation, and autophagy. Newly identified functions of complement include a key role in shaping metabolic reprogramming, which underlies T cell effector differentiation, and a role as a nexus for interactions with other effector systems, in particular the inflammasome and Notch transcription-factor networks. This review focuses on the contributions of complement to basic processes of the cell, in particular the integration of complement with cellular metabolism and the potential implications in infection and other disease settings. PMID:27533012

  5. REDOX REGULATION OF SIRT1 IN INFLAMMATION AND CELLULAR SENESCENCE

    PubMed Central

    Hwang, Jae-woong; Yao, Hongwei; Caito, Samuel; Sundar, Isaac K.; Rahman, Irfan

    2013-01-01

    Sirtuin1 (SIRT1) regulates inflammation, aging (lifespan and healthspan), calorie restriction/energetics, mitochondrial biogenesis, stress resistance, cellular senescence, endothelial functions, apoptosis/autophagy, and circadian rhythms through deacetylation of transcription factors and histones. SIRT1 level and activity are decreased in chronic inflammatory conditions and aging where oxidative stress occurs. SIRT1 is regulated by a NAD+-dependent DNA repair enzyme poly(ADP-ribose)-polymerase-1 (PARP-1), and subsequent NAD+ depletion by oxidative stresses may have consequent effects on inflammatory and stress responses as well as cellular senescence. SIRT1 has been shown to undergo covalent oxidative modifications by cigarette smoke-derived oxidants/aldehydes, leading to post-translational modifications, inactivation, and protein degradation. Furthermore, oxidant/carbonyl stress-mediated reduction of SIRT1 leads to the loss of its control on acetylation of target proteins including p53, RelA/p65 and FOXO3, thereby enhancing the inflammatory, pro-senescent and apoptotic responses, as well as endothelial dysfunction. In this review, the mechanisms of cigarette smoke/oxidant-mediated redox post-translational modifications of SIRT1 and its role in PARP1, NF-κB activation, FOXO3 and eNOS regulation, as well as chromatin remodeling/histone modifications during inflammaging are discussed. Furthermore, we also discussed various novel ways to activate SIRT1 either directly or indirectly, which may have therapeutic potential in attenuating inflammation and premature senescence involved in chronic lung diseases. PMID:23542362

  6. Cellular Bases of Light-regulated Gravity Responses

    NASA Technical Reports Server (NTRS)

    Roux, Stanley J.

    2003-01-01

    This report summarizes the most significant research accomplished in our NAG2-1347 project on the cellular bases of light-regulated gravity responses, It elaborates mainly on our discovery of the role of calcium currents in gravity-directed polar development in single germinating spore cells of the fern Ceratopteris, our development of RNA silencing as a viable method of suppressing the expression of specific genes in Ceratopteris, and on the structure, expression and distribution of members of the annexin family in flowering plants, especially Arabidopsis.

  7. Autophagy as a Regulated Pathway of Cellular Degradation

    PubMed Central

    Klionsky, Daniel J.; Emr, Scott D.

    2009-01-01

    Macroautophagy is a dynamic process involving the rearrangement of subcellular membranes to sequester cytoplasm and organelles for delivery to the lysosome or vacuole where the sequestered cargo is degraded and recycled. This process takes place in all eukaryotic cells. It is highly regulated through the action of various kinases, phosphatases, and guanosine triphosphatases (GTPases). The core protein machinery that is necessary to drive formation and consumption of intermediates in the macroautophagy pathway includes a ubiquitin-like protein conjugation system and a protein complex that directs membrane docking and fusion at the lysosome or vacuole. Macroautophagy plays an important role in developmental processes, human disease, and cellular response to nutrient deprivation. PMID:11099404

  8. Cellular manganese content is developmentally regulated in human dopaminergic neurons

    NASA Astrophysics Data System (ADS)

    Kumar, Kevin K.; Lowe, Edward W., Jr.; Aboud, Asad A.; Neely, M. Diana; Redha, Rey; Bauer, Joshua A.; Odak, Mihir; Weaver, C. David; Meiler, Jens; Aschner, Michael; Bowman, Aaron B.

    2014-10-01

    Manganese (Mn) is both an essential biological cofactor and neurotoxicant. Disruption of Mn biology in the basal ganglia has been implicated in the pathogenesis of neurodegenerative disorders, such as parkinsonism and Huntington's disease. Handling of other essential metals (e.g. iron and zinc) occurs via complex intracellular signaling networks that link metal detection and transport systems. However, beyond several non-selective transporters, little is known about the intracellular processes regulating neuronal Mn homeostasis. We hypothesized that small molecules that modulate intracellular Mn could provide insight into cell-level Mn regulatory mechanisms. We performed a high throughput screen of 40,167 small molecules for modifiers of cellular Mn content in a mouse striatal neuron cell line. Following stringent validation assays and chemical informatics, we obtained a chemical `toolbox' of 41 small molecules with diverse structure-activity relationships that can alter intracellular Mn levels under biologically relevant Mn exposures. We utilized this toolbox to test for differential regulation of Mn handling in human floor-plate lineage dopaminergic neurons, a lineage especially vulnerable to environmental Mn exposure. We report differential Mn accumulation between developmental stages and stage-specific differences in the Mn-altering activity of individual small molecules. This work demonstrates cell-level regulation of Mn content across neuronal differentiation.

  9. MOF maintains transcriptional programs regulating cellular stress response

    PubMed Central

    Sheikh, B N; Bechtel-Walz, W; Lucci, J; Karpiuk, O; Hild, I; Hartleben, B; Vornweg, J; Helmstädter, M; Sahyoun, A H; Bhardwaj, V; Stehle, T; Diehl, S; Kretz, O; Voss, A K; Thomas, T; Manke, T; Huber, T B; Akhtar, A

    2016-01-01

    MOF (MYST1, KAT8) is the major H4K16 lysine acetyltransferase (KAT) in Drosophila and mammals and is essential for embryonic development. However, little is known regarding the role of MOF in specific cell lineages. Here we analyze the differential role of MOF in proliferating and terminally differentiated tissues at steady state and under stress conditions. In proliferating cells, MOF directly binds and maintains the expression of genes required for cell cycle progression. In contrast, MOF is dispensable for terminally differentiated, postmitotic glomerular podocytes under physiological conditions. However, in response to injury, MOF is absolutely critical for podocyte maintenance in vivo. Consistently, we detect defective nuclear, endoplasmic reticulum and Golgi structures, as well as presence of multivesicular bodies in vivo in podocytes lacking Mof following injury. Undertaking genome-wide expression analysis of podocytes, we uncover several MOF-regulated pathways required for stress response. We find that MOF, along with the members of the non-specific lethal but not the male-specific lethal complex, directly binds to genes encoding the lysosome, endocytosis and vacuole pathways, which are known regulators of podocyte maintenance. Thus, our work identifies MOF as a key regulator of cellular stress response in glomerular podocytes. PMID:26387537

  10. Membrane organization and regulation of cellular Cholesterol homeostasis

    PubMed Central

    Jaureguiberry, María S.; Tricerri, M. Alejandra; Sanchez, Susana A; Garda, Horacio A; Finarelli, Gabriela S.; Gonzalez, Marina C.; Rimoldi, Omar J.

    2010-01-01

    An excess of intracellular free Cholesterol (Chol) is cytotoxic, and its homeostasis is crucial for cell viability. Apolipoprotein A–I (apoA-I) is a highly efficient Chol acceptor as it activates complex cellular pathways that tend to mobilize and export Chol from cellular depots. Here we hypothesize that membrane composition and/or organization is strongly involved in Chol homeostasis. To test this hypothesis, we constructed a cell line over expressing Stearoyl CoA desaturase (SCD-cells), which modifies plasma membrane (PM) composition by the enrichment of monounsaturated fatty,acids and determined this effect on membrane properties, cell viability and cholesterol homeostasis. PM in SCD-cells has a higher phospholipids/sphingomyelin ratio and is slightly enriched in Chol. These cells showed an increase in the cholesteryl esters/free Chol ratio, they were more resistant to Chol toxicity and in addition, they exported more caveolin than Control cells. The data suggest that cell functionality is preserved by regulating membrane fluidity and Chol exportation and storage. PMID:20336284

  11. Regulation of organismal proteostasis by trans-cellular chaperone signaling

    PubMed Central

    van Oosten-Hawle, Patricija; Porter, Robert S.; Morimoto, Richard I.

    2013-01-01

    Summary A major challenge for metazoans is to ensure that different tissues each expressing distinctive proteomes are, nevertheless, well protected at an organismal level from proteotoxic stress. We have examined this and show that expression of endogenous metastable protein sensors in muscle cells induces a systemic stress response throughout multiple tissues of C. elegans. Suppression of misfolding in muscle cells can be achieved not only by enhanced expression of HSP90 in muscle cells, but as effective by elevated expression of HSP90 in intestine or neuronal cells. This cell-non-autonomous control of HSP90 expression relies upon transcriptional feedback between somatic tissues that is regulated by the FoxA transcription factor PHA-4. This trans-cellular chaperone signaling response maintains organismal proteostasis when challenged by a local tissue imbalance in folding and provides the basis for a novel form of organismal stress sensing surveillance. PMID:23746847

  12. Regulation of System xc− by Pharmacological Manipulation of Cellular Thiols

    PubMed Central

    Albano, Rebecca; Raddatz, Nicholas J.; Hjelmhaug, Julie; Baker, David A.; Lobner, Doug

    2015-01-01

    The cystine/glutamate exchanger (system xc−) mediates the transport of cystine into the cell in exchange for glutamate. By releasing glutamate, system xc− can potentially cause excitotoxicity. However, through providing cystine to the cell, it regulates the levels of cellular glutathione (GSH), the main endogenous intracellular antioxidant, and may protect cells against oxidative stress. We tested two different compounds that deplete primary cortical cultures containing both neurons and astrocytes of intracellular GSH, L-buthionine-sulfoximine (L-BSO), and diethyl maleate (DEM). Both compounds caused significant concentration and time dependent decreases in intracellular GSH levels. However; DEM caused an increase in radiolabeled cystine uptake through system xc−, while unexpectedly BSO caused a decrease in uptake. The compounds caused similar low levels of neurotoxicity, while only BSO caused an increase in oxidative stress. The mechanism of GSH depletion by these two compounds is different, DEM directly conjugates to GSH, while BSO inhibits γ-glutamylcysteine synthetase, a key enzyme in GSH synthesis. As would be expected from these mechanisms of action, DEM caused a decrease in intracellular cysteine, while BSO increased cysteine levels. The results suggest that negative feedback by intracellular cysteine is an important regulator of system xc− in this culture system. PMID:25949770

  13. Regulation of System xc(-) by Pharmacological Manipulation of Cellular Thiols.

    PubMed

    Albano, Rebecca; Raddatz, Nicholas J; Hjelmhaug, Julie; Baker, David A; Lobner, Doug

    2015-01-01

    The cystine/glutamate exchanger (system xc (-)) mediates the transport of cystine into the cell in exchange for glutamate. By releasing glutamate, system xc (-) can potentially cause excitotoxicity. However, through providing cystine to the cell, it regulates the levels of cellular glutathione (GSH), the main endogenous intracellular antioxidant, and may protect cells against oxidative stress. We tested two different compounds that deplete primary cortical cultures containing both neurons and astrocytes of intracellular GSH, L-buthionine-sulfoximine (L-BSO), and diethyl maleate (DEM). Both compounds caused significant concentration and time dependent decreases in intracellular GSH levels. However; DEM caused an increase in radiolabeled cystine uptake through system xc (-), while unexpectedly BSO caused a decrease in uptake. The compounds caused similar low levels of neurotoxicity, while only BSO caused an increase in oxidative stress. The mechanism of GSH depletion by these two compounds is different, DEM directly conjugates to GSH, while BSO inhibits γ-glutamylcysteine synthetase, a key enzyme in GSH synthesis. As would be expected from these mechanisms of action, DEM caused a decrease in intracellular cysteine, while BSO increased cysteine levels. The results suggest that negative feedback by intracellular cysteine is an important regulator of system xc (-) in this culture system. PMID:25949770

  14. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in... intermodulation rejection ratio; 75 dB adjacent channel rejection ratio; −116 dBm reference sensitivity. (2) Voice... ratio; −116 dBm reference sensitivity....

  15. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in... intermodulation rejection ratio; 75 dB adjacent channel rejection ratio; −116 dBm reference sensitivity. (2) Voice... ratio; −116 dBm reference sensitivity....

  16. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in... intermodulation rejection ratio; 75 dB adjacent channel rejection ratio; −116 dBm reference sensitivity. (2) Voice... ratio; −116 dBm reference sensitivity....

  17. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in... intermodulation rejection ratio; 75 dB adjacent channel rejection ratio; −116 dBm reference sensitivity. (2) Voice... ratio; −116 dBm reference sensitivity....

  18. 47 CFR 22.970 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from cellular radiotelephone...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    .... Except as provided in 47 CFR 90.617(k), unacceptable interference to non-cellular part 90 licensees in... intermodulation rejection ratio; 75 dB adjacent channel rejection ratio; −116 dBm reference sensitivity. (2) Voice... ratio; −116 dBm reference sensitivity....

  19. Multiple roles for Puralpha in cellular and viral regulation.

    PubMed

    White, Martyn K; Johnson, Edward M; Khalili, Kamel

    2009-02-01

    Pur-alpha is a ubiquitous multifunctional protein that is strongly conserved throughout evolution, binds to both DNA and RNA and functions in the initiation of DNA replication, control of transcription and mRNA translation. In addition, it binds to several cellular regulatory proteins including the retinoblastoma protein, E2F-1, Sp1, YB-1, cyclin T1/Cdk9 and cyclin A/Cdk2. These observations and functional studies provide evidence that Puralpha is a major player in the regulation of the cell cycle and oncogenic transformation. Puralpha also binds to viral proteins such as the large T-antigen of JC virus (JCV) and the Tat protein of human immunodeficiency virus-1 (HIV-1) and plays a role in the cross-communication of these viruses in the opportunistic polyomavirus JC (JCV) brain infection, progressive multifocal leukoencephalopathy (PML). The creation of transgenic mice with inactivation of the PURA gene that encodes Puralpha has revealed that Puralpha is critical for postnatal brain development and has unraveled an essential role of Puralpha in the transport of specific mRNAs to the dendrites and the establishment of the postsynaptic compartment in the developing neurons. Finally, the availability of cell cultures from the PURA knockout mice has allowed studies that have unraveled a role for Puralpha in DNA repair. PMID:19182532

  20. ERK1/2 can feedback-regulate cellular MEK1/2 levels.

    PubMed

    Hong, Seung-Keun; Wu, Pui-Kei; Karkhanis, Mansi; Park, Jong-In

    2015-10-01

    Signal transduction of the Raf/MEK/ERK pathway is regulated by various feedback mechanisms. Given the greater molar ratio between Raf-MEK than between MEK-ERK in cells, it may be possible that MEK1/2 levels are regulated to modulate Raf/MEK/ERK activity upon pathway stimulation. Nevertheless, it has not been reported whether MEK1/2 expression can be subject to a feedback regulation. Here, we report that the Raf/MEK/ERK pathway can feedback-regulate cellular MEK1 and MEK2 levels. In different cell types, ΔRaf-1:ER- or B-Raf(V600E)-mediated MEK/ERK activation increased MEK1 but decreased MEK2 levels. These regulations were abrogated by ERK1/2 knockdown mediated by RNA interference, suggesting the presence of a feedback mechanism that regulates MEK1/2 levels. Subsequently, analyses using qPCR and luciferase reporters of the DNA promoter and 3' untranslated region revealed that the feedback MEK1 upregulation was in part attributed to increased transcription. However, the feedback MEK2 downregulation was only observed at protein levels, which was blocked by the proteasome inhibitors, MG132 and bortezomib, suggesting that the MEK2 regulation is mediated at a post-translational level. These results suggest that the Raf/MEK/ERK pathway can feedback-regulate cellular levels of MEK1 and MEK2, wherein MEK1 levels are upregulated at transcriptional level whereas MEK2 levels are downregulated at posttranslational level. PMID:26163823

  1. Mitochondrial uncoupling proteins regulate angiotensin-converting enzyme expression: crosstalk between cellular and endocrine metabolic regulators suggested by RNA interference and genetic studies.

    PubMed

    Dhamrait, Sukhbir S; Maubaret, Cecilia; Pedersen-Bjergaard, Ulrik; Brull, David J; Gohlke, Peter; Payne, John R; World, Michael; Thorsteinsson, Birger; Humphries, Steve E; Montgomery, Hugh E

    2016-07-01

    Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin-converting enzyme (ACE) is the central component of endocrine and local tissue renin-angiotensin systems (RAS), which also regulate diverse aspects of whole-body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations (healthy young UK men and Scandinavian diabetic patients) serum ACE (sACE) activity was significantly higher amongst UCP3-55C (rather than T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold (P < 0·01) whilst increasing ACE expression within a physiological range (<1·8-fold at 48 h; P < 0·01). Our findings suggest novel hypotheses. Firstly, cellular feedback regulation may occur between UCPs and ACE. Secondly, cellular UCP regulation of sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role. PMID:27417115

  2. Mitochondrial uncoupling proteins regulate angiotensin‐converting enzyme expression: crosstalk between cellular and endocrine metabolic regulators suggested by RNA interference and genetic studies

    PubMed Central

    Maubaret, Cecilia; Pedersen‐Bjergaard, Ulrik; Brull, David J.; Gohlke, Peter; Payne, John R.; World, Michael; Thorsteinsson, Birger; Humphries, Steve E.; Montgomery, Hugh E.

    2015-01-01

    Uncoupling proteins (UCPs) regulate mitochondrial function, and thus cellular metabolism. Angiotensin‐converting enzyme (ACE) is the central component of endocrine and local tissue renin–angiotensin systems (RAS), which also regulate diverse aspects of whole‐body metabolism and mitochondrial function (partly through altering mitochondrial UCP expression). We show that ACE expression also appears to be regulated by mitochondrial UCPs. In genetic analysis of two unrelated populations (healthy young UK men and Scandinavian diabetic patients) serum ACE (sACE) activity was significantly higher amongst UCP3‐55C (rather than T) and UCP2 I (rather than D) allele carriers. RNA interference against UCP2 in human umbilical vein endothelial cells reduced UCP2 mRNA sixfold (P < 0·01) whilst increasing ACE expression within a physiological range (<1·8‐fold at 48 h; P < 0·01). Our findings suggest novel hypotheses. Firstly, cellular feedback regulation may occur between UCPs and ACE. Secondly, cellular UCP regulation of sACE suggests a novel means of crosstalk between (and mutual regulation of) cellular and endocrine metabolism. This might partly explain the reduced risk of developing diabetes and metabolic syndrome with RAS antagonists and offer insight into the origins of cardiovascular disease in which UCPs and ACE both play a role.

  3. 21 CFR 1271.10 - Are my HCT/P's regulated solely under section 361 of the PHS Act and the regulations in this part...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Are my HCT/P's regulated solely under section 361..., AND CELLULAR AND TISSUE-BASED PRODUCTS General Provisions § 1271.10 Are my HCT/P's regulated solely.../P is regulated solely under section 361 of the PHS Act and the regulations in this part if it...

  4. Nanotopographical modification: a regulator of cellular function through focal adhesions

    PubMed Central

    Biggs, Manus Jonathan Paul; Richards, R. Geoff; Dalby, Matthew J.

    2010-01-01

    As materials technology and the field of biomedical engineering advances, the role of cellular mechanisms, in particular adhesive interactions with implantable devices, becomes more relevant in both research and clinical practice. A key tenet of medical device design has evolved from the exquisite ability of biological systems to respond to topographical features or chemical stimuli, a process that has led to the development of next-generation biomaterials for a wide variety of clinical disorders. In vitro studies have identified nanoscale features as potent modulators of cellular behavior through the onset of focal adhesion formation. The focus of this review is on the recent developments concerning the role of nanoscale structures on integrin-mediated adhesion and cellular function with an emphasis on the generation of medical constructs with regenerative applications. PMID:20138244

  5. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part 22 Cellular Radiotelephone systems, and within the 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED)...

  6. Regulation of myokine expression: Role of exercise and cellular stress.

    PubMed

    Ost, Mario; Coleman, Verena; Kasch, Juliane; Klaus, Susanne

    2016-09-01

    Exercise training is well known to improve physical fitness and to combat chronic diseases and aging related disorders. Part of this is thought to be mediated by myokines, muscle derived secretory proteins (mainly cytokines) that elicit auto/paracrine but also endocrine effects on organs such as liver, adipose tissue, and bone. Today, several hundred potential myokines have been identified most of them not exclusive to muscle cells. Strenuous exercise is associated with increased production of free radicals and reactive oxidant species (ROS) as well as endoplasmic reticulum (ER)-stress which at an excessive level can lead to muscle damage and cell death. On the other hand, transient elevations in oxidative and ER-stress are thought to be necessary for adaptive improvements by regular exercise through a hormesis action termed mitohormesis since mitochondria are essential for the generation of energy and tightly connected to ER- and oxidative stress. Exercise induced myokines have been identified by various in vivo and in vitro approaches and accumulating evidence suggests that ROS and ER-stress linked pathways are involved in myokine induction. For example, interleukin (IL)-6, the prototypic exercise myokine is also induced by oxidative and ER-stress. Exercise induced expression of some myokines such as irisin and meteorin-like is linked to the transcription factor PGC-1α and apparently not related to ER-stress whereas typical ER-stress induced cytokines such as FGF-21 and GDF-15 are not exercise myokines under normal physiological conditions. Recent technological advances have led to the identification of numerous potential new myokines but for most of them regulation by oxidative and ER-stress still needs to be unraveled. PMID:26898145

  7. US Food and Drug Administration international collaborations for cellular therapy product regulation

    PubMed Central

    2012-01-01

    Cellular therapy products are an emerging medical product class undergoing rapid scientific and clinical innovation worldwide. These products pose unique regulatory challenges both for countries with existing regulatory frameworks and for countries where regulatory frameworks for cellular therapy products are under development. The United States Food and Drug Administration (US FDA) has a history of productive working relationships with international regulatory authorities, and seeks to extend this to the cellular therapy field. The US FDA and its global regulatory counterparts are engaged in collaborations focused on the convergence of scientific and regulatory approaches, and the education of scientists, clinicians, regulators, and the public at large on the development of cellular therapies. PMID:23021082

  8. Oxidative Stress, Redox Regulation and Diseases of Cellular Differentiation

    PubMed Central

    Ye, Zhi-Wei; Zhang, Jie; Townsend, Danyelle M.; Tew, Kenneth D.

    2015-01-01

    Background Within cells, there is a narrow concentration threshold that governs whether reactive oxygen species (ROS) induce toxicity or act as second messengers. Scope of review We discuss current understanding of how ROS arise, facilitate cell signaling, cause toxicities and disease related to abnormal cell differentiation and those (primarily) sulfur based pathways that provide nucleophilicity to offset these effects. Primary conclusions Cellular redox homeostasis mediates a plethora of cellular pathways that determine life and death events. For example, ROS intersect with GSH based enzyme pathways to influence cell differentiation, a process integral to normal hematopoiesis, but also affecting a number of diverse cell differentiation related human diseases. Recent attempts to manage such pathologies have focused on intervening in some of these pathways, with the consequence that differentiation therapy targeting redox homeostasis has provided a platform for drug discovery and development. General Significance The balance between electrophilic oxidative stress and protective biomolecular nucleophiles predisposes the evolution of modern life forms. Imbalances of the two can produce aberrant redox homeostasis with resultant pathologies. Understanding the pathways involved provides opportunities to consider interventional strategies. PMID:25445706

  9. S-glutathionylation uncouples eNOS and regulates its cellular and vascular function

    PubMed Central

    Chen, Chun-An; Wang, Tse-Yao; Varadharaj, Saradhadevi; Reyes, Levy A.; Hemann, Craig; Hassan Talukder, M. A.; Chen, Yeong-Renn; Druhan, Lawrence J.; Zweier, Jay L.

    2012-01-01

    Endothelial nitric oxide synthase (eNOS) is critical in the regulation of vascular function, and can generate both nitric oxide (NO) and superoxide (O2•−), which are key mediators of cellular signalling. In the presence of Ca2+/calmodulin, eNOS produces NO, endothelial-derived relaxing factor, from L-arginine (L-Arg) by means of electron transfer from NADPH through a flavin containing reductase domain to oxygen bound at the haem of an oxygenase domain, which also contains binding sites for tetrahydrobiopterin (BH4) and L-Arg1–3. In the absence of BH4, NO synthesis is abrogated and instead O2•− is generated4–7. While NOS dysfunction occurs in diseases with redox stress, BH4 repletion only partly restores NOS activity and NOS-dependent vasodilation7. This suggests that there is an as yet unidentified redox-regulated mechanism controlling NOS function. Protein thiols can undergo S-glutathionylation, a reversible protein modification involved in cellular signalling and adaptation8,9. Under oxidative stress, S-glutathionylation occurs through thiol–disulphide exchange with oxidized glutathione or reaction of oxidant-induced protein thiyl radicals with reduced glutathione10,11. Cysteine residues are critical for the maintenance of eNOS function12,13; we therefore speculated that oxidative stress could alter eNOS activity through S-glutathionylation. Here we show that S-glutathionylation of eNOS reversibly decreases NOS activity with an increase in O2•− generation primarily from the reductase, in which two highly conserved cysteine residues are identified as sites of S-glutathionylation and found to be critical for redox-regulation of eNOS function. We show that eNOS S-glutathionylation in endothelial cells, with loss of NO and gain of O2•− generation, is associated with impaired endothelium-dependent vasodilation. In hypertensive vessels, eNOS S-glutathionylation is increased with impaired endothelium-dependent vasodilation that is restored by thiol

  10. ATR-mediated regulation of nuclear and cellular plasticity.

    PubMed

    Kidiyoor, Gururaj Rao; Kumar, Amit; Foiani, Marco

    2016-08-01

    ATR (Ataxia Telangiectasia and Rad3-related) is a member of the Phosphatidylinositol 3-kinase-related kinases (PIKKs) family, amongst six other vertebrate proteins known so far. ATR is indispensable for cell survival and its essential role is in sensing DNA damage and initiating appropriate repair responses. In this review we highlight emerging and recent observations connecting ATR to alternative roles in controlling the nuclear envelope, nucleolus, centrosome and other organelles in response to both internal and external stress conditions. We propose that ATR functions control cell plasticity by sensing structural deformations of different cellular components, including DNA and initiating appropriate repair responses, most of which are yet to be understood completely. PMID:27283761

  11. From Syncitium to Regulated Pump: A Cardiac Muscle Cellular Update

    ERIC Educational Resources Information Center

    Korzick, Donna H.

    2011-01-01

    The primary purpose of this article is to present a basic overview of some key teaching concepts that should be considered for inclusion in an six- to eight-lecture introductory block on the regulation of cardiac performance for graduate students. Within the context of cardiac excitation-contraction coupling, this review incorporates information…

  12. Drosophila Myc: a master regulator of cellular performance

    PubMed Central

    Grifoni, Daniela; Bellosta, Paola

    2014-01-01

    The identification of the Drosophila homolog of the human MYC oncogene has fostered a series of studies aimed to address its functions in development and cancer biology. Due to its essential roles in many fundamental biological processes it is hard to imagine a molecular mechanism in which MYC function is not required. For this reason, the easily manipulated Drosophila system has greatly helped in the dissection of the genetic and molecular pathways that regulate and are regulated by MYC function. In this review, we focus on studies of MYC in the fruitfly with particular emphasis on metabolism and cell competition, highlighting the contributions of this model system in the last decade to our understanding of MYC’s complex biological nature. PMID:25010747

  13. Cellular adaptation to hypoxia and p53 transcription regulation.

    PubMed

    Zhao, Yang; Chen, Xue-qun; Du, Ji-zeng

    2009-05-01

    Tumor suppressor p53 is the most frequently mutated gene in human tumors. Meanwhile, under stress conditions, p53 also acts as a transcription factor, regulating the expression of a series of target genes to maintain the integrity of genome. The target genes of p53 can be classified into genes regulating cell cycle arrest, genes involved in apoptosis, and genes inhibiting angiogenesis. p53 protein contains a transactivation domain, a sequence-specific DNA binding domain, a tetramerization domain, a non-specific DNA binding domain that recognizes damaged DNA, and a later identified proline-rich domain. Under stress, p53 proteins accumulate and are activated through two mechanisms. One, involving ataxia telangiectasia-mutated protein (ATM), is that the interaction between p53 and its down-regulation factor murine double minute 2 (MDM2) decreases, leading to p53 phosphorylation on Ser15, as determined by the post-translational mechanism; the other holds that p53 increases and is activated through the binding of ribosomal protein L26 (RPL26) or nucleolin to p53 mRNA 5( untranslated region (UTR), regulating p53 translation. Under hypoxia, p53 decreases transactivation and increases transrepression. The mutations outside the DNA binding domain of p53 also contribute to tumor progress, so further studies on p53 should also be focused on this direction. The subterranean blind mole rat Spalax in Israel is a good model for hypoxia-adaptation. The p53 of Spalax mutated in residue 172 and residue 207 from arginine to lysine, conferring it the ability to survive hypoxic conditions. This model indicates that p53 acts as a master gene of diversity formation during evolution. PMID:19434769

  14. Feed-forward regulation ensures stability and rapid reversibility of a cellular state

    PubMed Central

    Doncic, Andreas; Skotheim, Jan M.

    2013-01-01

    Cellular transitions are important for all life. Such transitions, including cell fate decisions, often employ positive feedback regulation to establish and stabilize new cellular states. However, positive feedback is unlikely to underlie stable cell cycle arrest in yeast exposed to mating pheromone because the signaling pathway is linear, rather than bistable, over a broad range of extracellular pheromone concentration. We show that the stability of the pheromone arrested state results from coherent feed-forward regulation of the cell cycle inhibitor Far1. This network motif is effectively isolated from the more complex regulatory network in which it is embedded. Fast regulation of Far1 by phosphorylation allows rapid cell cycle arrest and reentry, whereas slow Far1 synthesis reinforces arrest. We thus expect coherent feed-forward regulation to be frequently implemented at reversible cellular transitions because this network motif can achieve the ostensibly conflicting aims of arrest stability and rapid reversibility without loss of signaling information. PMID:23685071

  15. Viral Replication Protein Inhibits Cellular Cofilin Actin Depolymerization Factor to Regulate the Actin Network and Promote Viral Replicase Assembly

    PubMed Central

    Kovalev, Nikolay; de Castro Martín, Isabel Fernández; Barajas, Daniel; Risco, Cristina; Nagy, Peter D.

    2016-01-01

    RNA viruses exploit host cells by co-opting host factors and lipids and escaping host antiviral responses. Previous genome-wide screens with Tomato bushy stunt virus (TBSV) in the model host yeast have identified 18 cellular genes that are part of the actin network. In this paper, we show that the p33 viral replication factor interacts with the cellular cofilin (Cof1p), which is an actin depolymerization factor. Using temperature-sensitive (ts) Cof1p or actin (Act1p) mutants at a semi-permissive temperature, we find an increased level of TBSV RNA accumulation in yeast cells and elevated in vitro activity of the tombusvirus replicase. We show that the large p33 containing replication organelle-like structures are located in the close vicinity of actin patches in yeast cells or around actin cable hubs in infected plant cells. Therefore, the actin filaments could be involved in VRC assembly and the formation of large viral replication compartments containing many individual VRCs. Moreover, we show that the actin network affects the recruitment of viral and cellular components, including oxysterol binding proteins and VAP proteins to form membrane contact sites for efficient transfer of sterols to the sites of replication. Altogether, the emerging picture is that TBSV, via direct interaction between the p33 replication protein and Cof1p, controls cofilin activities to obstruct the dynamic actin network that leads to efficient subversion of cellular factors for pro-viral functions. In summary, the discovery that TBSV interacts with cellular cofilin and blocks the severing of existing filaments and the formation of new actin filaments in infected cells opens a new window to unravel the way by which viruses could subvert/co-opt cellular proteins and lipids. By regulating the functions of cofilin and the actin network, which are central nodes in cellular pathways, viruses could gain supremacy in subversion of cellular factors for pro-viral functions. PMID:26863541

  16. Glutathione and cellular redox control in epigenetic regulation.

    PubMed

    García-Giménez, José Luis; Ibañez-Cabellos, José Santiago; Seco-Cervera, Marta; Pallardó, Federico V

    2014-10-01

    Epigenetics is defined as the mitotically/meiotically heritable changes in gene expression that are not due to changes in the primary DNA sequence. Over recent years, growing evidence has suggested a link between redox metabolism and the control of epigenetic mechanisms. The effect of the redox control, oxidative stress, and glutathione (GSH) on the epigenetic mechanisms occur at different levels affecting DNA methylation, miRNAs expression, and histone post-translational modifications (PTMs). Furthermore, a number of redox PTMs are being described, so enriching the histone code. Pioneer works showed how oxidized GSH inhibits the activity of S-adenosyl methionine synthetase, MAT1A, a key enzyme involved in the synthesis of S-adenosyl methionine (SAM), which is used by DNA methyltransferases (DNMTs) and histone methyltransferases (HMTs). Alteration in NAD /NADH ratio affects the activity of class III histone deacetylases (HDACs) and poly-ADP ribosyltransferases (PARPs). Furthermore, the iron redox state of the catalytic center of key enzymes influences the activity of HDACs and the activity of Tet methylcytosine dioxygenases (DNA demetylases) and JmjC histone demethylases. In this communication, we will show the intricate mechanisms that participate in the redox control of the epigenetic mechanisms. We specially focus our work in the characterization of new PTMs in histones, such as histone carbonylation and glutathionylation. Demonstrating how GSH influences the epigenetic mechanisms beyond a mere regulation of SAM levels. The mechanisms described in this communication place GSH and redox control in the landscape of the epigenetic regulation. The results shown underscore the relevant role that oxidative stress and GSH play as key factors in epigenetics, opening a new window for understating the underlying mechanisms that control cell differentiation, proliferation, development, and disease. PMID:26461333

  17. Regulation of mucin secretion from in vitro cellular models.

    PubMed

    Davis, C William

    2002-01-01

    Conceptually, in vitro models for airway mucin secretion may provide useful information pertinent to many aspects of goblet cell biology/physiology. Such models may be especially useful in identifying potential secretagogues, probing the distribution of receptors between goblet cell apical and basolateral membrane domains, and revealing intracellular messenger pathways underlying receptor activation. We have focused most recently on human bronchial epithelial cell cultures grown as tracheal xenografts and SPOC1 cell cultures. These two models are remarkably similar with respect to the regulation of mucin secretion: luminal challenges with the P2Y2 purinoceptor agonists ATP or UTP elicit mucin secretion with EC50s of about 3 microM and archetypal agonists to other purinoceptors test negative. P2Y2 purinoceptors typically couple via Gq to phospholipase C, suggesting that intracellular Ca2+ and protein kinase C (PKC) are important in activating intracellular pathways leading to goblet cell mucin release. Consistent with this notion, phorbol myristate acetate and ionomycin elicit mucin secretion from SPOC1 cells and HBE xenografts, whereas cyclic nucleotides do not. Delineation of the molecules comprising these receptor/messenger interactions and their supporting pathways remains an important challenge for the development of drugs effective in therapeutic interventions in mucin hypersecretory airway diseases; with these models we have initiated the process. PMID:12568491

  18. Design mobile satellite system architecture as an integral part of the cellular access digital network

    NASA Technical Reports Server (NTRS)

    Chien, E. S. K.; Marinho, J. A.; Russell, J. E., Sr.

    1988-01-01

    The Cellular Access Digital Network (CADN) is the access vehicle through which cellular technology is brought into the mainstream of the evolving integrated telecommunications network. Beyond the integrated end-to-end digital access and per call network services provisioning of the Integrated Services Digital Network (ISDN), the CADN engenders the added capability of mobility freedom via wireless access. One key element of the CADN network architecture is the standard user to network interface that is independent of RF transmission technology. Since the Mobile Satellite System (MSS) is envisioned to not only complement but also enhance the capabilities of the terrestrial cellular telecommunications network, compatibility and interoperability between terrestrial cellular and mobile satellite systems are vitally important to provide an integrated moving telecommunications network of the future. From a network standpoint, there exist very strong commonalities between the terrestrial cellular system and the mobile satellite system. Therefore, the MSS architecture should be designed as an integral part of the CADN. This paper describes the concept of the CADN, the functional architecture of the MSS, and the user-network interface signaling protocols.

  19. Creating Order from Chaos: Cellular Regulation by Kinase Anchoring

    PubMed Central

    Scott, John D.; Dessauer, Carmen W.; Tasken, Kjetil

    2012-01-01

    Second messenger responses rely on where and when the enzymes that propagate these signals become active. Spatial and temporal organization of certain signaling enzymes is controlled in part by A-kinase anchoring proteins (AKAPs). This family of regulatory proteins was originally classified on the basis of their ability to compartmentalize the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (also known as protein kinase A, or PKA). However, it is now recognized that AKAPs position G protein–coupled receptors, adenylyl cyclases, G proteins, and their effector proteins in relation to protein kinases and signal termination enzymes such as phosphodiesterases and protein phosphatases. This arrangement offers a simple and efficient means to limit the scope, duration, and directional flow of information to sites deep within the cell. This review focuses on the pros and cons of reagents that define the biological role of kinase anchoring inside cells and discusses recent advances in our understanding of anchored second messenger signaling in the cardiovascular and immune systems. PMID:23043438

  20. The role of focal adhesion kinase in the regulation of cellular mechanical properties

    NASA Astrophysics Data System (ADS)

    Mierke, Claudia Tanja

    2013-12-01

    The regulation of mechanical properties is necessary for cell invasion into connective tissue or intra- and extravasation through the endothelium of blood or lymph vessels. Cell invasion is important for the regulation of many healthy processes such as immune response reactions and wound healing. In addition, cell invasion plays a role in disease-related processes such as tumor metastasis and autoimmune responses. Until now the role of focal adhesion kinase (FAK) in regulating mechanical properties of cells and its impact on cell invasion efficiency is still not well known. Thus, this review focuses on mechanical properties regulated by FAK in comparison to the mechano-regulating protein vinculin. Moreover, it points out the connection between cancer cell invasion and metastasis and FAK by showing that FAK regulates cellular mechanical properties required for cellular motility. Furthermore, it sheds light on the indirect interaction of FAK with vinculin by binding to paxillin, which then impairs the binding of paxillin to vinculin. In addition, this review emphasizes whether FAK fulfills regulatory functions similar to vinculin. In particular, it discusses the differences and the similarities between FAK and vinculin in regulating the biomechanical properties of cells. Finally, this paper highlights that both focal adhesion proteins, vinculin and FAK, synergize their functions to regulate the mechanical properties of cells such as stiffness and contractile forces. Subsequently, these mechanical properties determine cellular invasiveness into tissues and provide a source sink for future drug developments to inhibit excessive cell invasion and hence, metastases formation.

  1. Polyamines regulate cell growth and cellular methylglyoxal in high-glucose medium independently of intracellular glutathione.

    PubMed

    Kwak, Min-Kyu; Lee, Mun-Hyoung; Park, Seong-Jun; Shin, Sang-Min; Liu, Rui; Kang, Sa-Ouk

    2016-03-01

    Polyamines can presumably inhibit protein glycation, when associated with the methylglyoxal inevitably produced during glycolysis. Herein, we hypothesized a nonenzymatic interaction between putrescine and methylglyoxal in putrescine-deficient or -overexpressing Dictyostelium cells in high-glucose medium, which can control methylglyoxal production. Putrescine was essentially required for growth rescue accompanying methylglyoxal detoxification when cells underwent growth defect and cell cycle G1-arrest when supplemented with high glucose. Furthermore, methylglyoxal regulation by putrescine seemed to be a parallel pathway independent of the changes in cellular glutathione content in high-glucose medium. Consequently, we suggest that Dictyostelium cells need polyamines for normal growth and cellular methylglyoxal regulation. PMID:26898161

  2. Epigenomic Regulation of Smad1 Signaling During Cellular Senescence Induced by Ras Activation.

    PubMed

    Kaneda, Atsushi; Nonaka, Aya; Fujita, Takanori; Yamanaka, Ryota; Fujimoto, Mai; Miyazono, Kohei; Aburatani, Hiroyuki

    2016-01-01

    Epigenomic modification plays important roles in regulating gene expression during development, differentiation, and cellular senescence. When oncogenes are activated, cells fall into stable growth arrest to block cellular proliferation, which is called oncogene-induced senescence. We recently identified through genome-wide analyses that Bmp2-Smad1 signal and its regulation by harmonized epigenomic alteration play an important role in Ras-induced senescence of mouse embryonic fibroblasts. We describe in this chapter the methods for analyses of epigenomic alteration and Smad1 targets on genome-wide scale. PMID:26520136

  3. Novel Mechanism of Regulation of Tomato Bushy Stunt Virus Replication by Cellular WW-Domain Proteins

    PubMed Central

    Barajas, Daniel; Kovalev, Nikolay; Qin, Jun

    2014-01-01

    ABSTRACT Replication of (+)RNA viruses depends on several co-opted host proteins but is also under the control of cell-intrinsic restriction factors (CIRFs). By using tombusviruses, small model viruses of plants, we dissect the mechanism of inhibition of viral replication by cellular WW-domain-containing proteins, which act as CIRFs. By using fusion proteins between the WW domain and the p33 replication protein, we show that the WW domain inhibits the ability of p33 to bind to the viral RNA and to other p33 and p92 replication proteins leading to inhibition of viral replication in yeast and in a cell extract. Overexpression of WW-domain protein in yeast also leads to reduction of several co-opted host factors in the viral replicase complex (VRC). These host proteins, such as eEF1A, Cdc34 E2 ubiquitin-conjugating enzyme, and ESCRT proteins (Bro1p and Vps4p), are known to be involved in VRC assembly. Simultaneous coexpression of proviral cellular factors with WW-domain protein partly neutralizes the inhibitory effect of the WW-domain protein. We propose that cellular WW-domain proteins act as CIRFs and also as regulators of tombusvirus replication by inhibiting the assembly of new membrane-bound VRCs at the late stage of infection. We suggest that tombusviruses could sense the status of the infected cells via the availability of cellular susceptibility factors versus WW-domain proteins for binding to p33 replication protein that ultimately controls the formation of new VRCs. This regulatory mechanism might explain how tombusviruses could adjust the efficiency of RNA replication to the limiting resources of the host cells during infections. IMPORTANCE Replication of positive-stranded RNA viruses, which are major pathogens of plants, animals, and humans, is inhibited by several cell-intrinsic restriction factors (CIRFs) in infected cells. We define here the inhibitory roles of the cellular Rsp5 ubiquitin ligase and its WW domain in plant-infecting tombusvirus

  4. Odd-skipped related 2 is epigenetically regulated in cellular quiescence

    SciTech Connect

    Kawai, Shinji; Amano, Atsuo

    2010-06-11

    Cellular behavior and development are extensively altered during the transition from cell cycle into quiescence, though the mechanism involved in establishing and maintaining quiescence is largely unknown. We found that Odd-skipped related 2 (Osr2) was up-regulated during cellular quiescence by serum starvation as well as culturing to confluence. To investigate the regulatory mechanism of Osr2 under these conditions, we characterized the mouse Osr2 promoter. CpG islands in the flanking region of the transcription start site were predominantly methylated in exponentially growing cells, resulting in silencing of Osr2 expression. In addition, CpG demethylation in quiescence caused activation of Osr2 expression, while acetylation of the H3 and H4 histones during quiescence also led to an increase in Osr2 expression. These results suggest that epigenetically regulated Osr2 plays an important role in cellular quiescence and proliferation.

  5. 77 FR 53873 - Defense Transportation Regulation, Part IV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... of the Secretary Defense Transportation Regulation, Part IV AGENCY: United States Transportation... Transportation Regulation (DTR) Part IV (DTR 4500.9R). These business rules will encompass Transportation Service... CONTACT: Mr. Jim Teague, United States Transportation Command, TCJ5/4-PI, 508 Scott Drive, Scott Air...

  6. 19 CFR Appendix to Part 181 - Rules of Origin Regulations

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 19 Customs Duties 2 2014-04-01 2014-04-01 false Rules of Origin Regulations Appendix to Part 181 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) NORTH AMERICAN FREE TRADE AGREEMENT Pt. 181, App. Appendix to Part 181—Rules of Origin Regulations SECTION 1. CITATION...

  7. 19 CFR Appendix to Part 181 - Rules of Origin Regulations

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 19 Customs Duties 2 2012-04-01 2012-04-01 false Rules of Origin Regulations Appendix to Part 181 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) NORTH AMERICAN FREE TRADE AGREEMENT Pt. 181, App. Appendix to Part 181—Rules of Origin Regulations SECTION 1. CITATION...

  8. 19 CFR Appendix to Part 181 - Rules of Origin Regulations

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 19 Customs Duties 2 2013-04-01 2013-04-01 false Rules of Origin Regulations Appendix to Part 181 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) NORTH AMERICAN FREE TRADE AGREEMENT Pt. 181, App. Appendix to Part 181—Rules of Origin Regulations SECTION 1. CITATION...

  9. 78 FR 18325 - Defense Transportation Regulation, Part IV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-26

    ... of the Secretary Defense Transportation Regulation, Part IV AGENCY: United States Transportation Command (USTRANSCOM), DoD. ACTION: Announcement. SUMMARY: On September 4, 2012 (77 FR 53873-53874), the Department of Defense published a notice titled Defense Transportation Regulation, Part IV. DoD has...

  10. 75 FR 16445 - Defense Transportation Regulation, Part IV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-01

    ... of the Secretary Defense Transportation Regulation, Part IV AGENCY: United States Transportation... for the Defense Personal Property Program (DP3) in the Defense Transportation Regulation (DTR) Part IV.... Jim Teague, United States Transportation Command, TCJ5/4-PI, 508 Scott Drive, Scott Air Force Base,...

  11. Regulation of cellular communication by signaling microdomains in the blood vessel wall.

    PubMed

    Billaud, Marie; Lohman, Alexander W; Johnstone, Scott R; Biwer, Lauren A; Mutchler, Stephanie; Isakson, Brant E

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function. PMID:24671377

  12. Regulation of Cellular Communication by Signaling Microdomains in the Blood Vessel Wall

    PubMed Central

    Billaud, Marie; Lohman, Alexander W.; Johnstone, Scott R.; Biwer, Lauren A.; Mutchler, Stephanie; Isakson, Brant E.

    2014-01-01

    It has become increasingly clear that the accumulation of proteins in specific regions of the plasma membrane can facilitate cellular communication. These regions, termed signaling microdomains, are found throughout the blood vessel wall where cellular communication, both within and between cell types, must be tightly regulated to maintain proper vascular function. We will define a cellular signaling microdomain and apply this definition to the plethora of means by which cellular communication has been hypothesized to occur in the blood vessel wall. To that end, we make a case for three broad areas of cellular communication where signaling microdomains could play an important role: 1) paracrine release of free radicals and gaseous molecules such as nitric oxide and reactive oxygen species; 2) role of ion channels including gap junctions and potassium channels, especially those associated with the endothelium-derived hyperpolarization mediated signaling, and lastly, 3) mechanism of exocytosis that has considerable oversight by signaling microdomains, especially those associated with the release of von Willebrand factor. When summed, we believe that it is clear that the organization and regulation of signaling microdomains is an essential component to vessel wall function. PMID:24671377

  13. Junb regulates arterial contraction capacity, cellular contractility, and motility via its target Myl9 in mice.

    PubMed

    Licht, Alexander H; Nübel, Tobias; Feldner, Anja; Jurisch-Yaksi, Nathalie; Marcello, Marco; Demicheva, Elena; Hu, Jun-Hao; Hartenstein, Bettina; Augustin, Hellmut G; Hecker, Markus; Angel, Peter; Korff, Thomas; Schorpp-Kistner, Marina

    2010-07-01

    Cellular contractility and, thus, the ability to alter cell shape are prerequisites for a number of important biological processes such as cytokinesis, movement, differentiation, and substrate adherence. The contractile capacity of vascular smooth muscle cells (VSMCs) is pivotal for the regulation of vascular tone and thus blood pressure and flow. Here, we report that conditional ablation of the transcriptional regulator Junb results in impaired arterial contractility in vivo and in vitro. This was exemplified by resistance of Junb-deficient mice to DOCA-salt-induced volume-dependent hypertension as well as by a decreased contractile capacity of isolated arteries. Detailed analyses of Junb-deficient VSMCs, mouse embryonic fibroblasts, and endothelial cells revealed a general failure in stress fiber formation and impaired cellular motility. Concomitantly, we identified myosin regulatory light chain 9 (Myl9), which is critically involved in actomyosin contractility and stress fiber assembly, as a Junb target. Consistent with these findings, reexpression of either Junb or Myl9 in Junb-deficient cells restored stress fiber formation, cellular motility, and contractile capacity. Our data establish a molecular link between the activator protein-1 transcription factor subunit Junb and actomyosin-based cellular motility as well as cellular and vascular contractility by governing Myl9 transcription. PMID:20551518

  14. Junb regulates arterial contraction capacity, cellular contractility, and motility via its target Myl9 in mice

    PubMed Central

    Licht, Alexander H.; Nübel, Tobias; Feldner, Anja; Jurisch-Yaksi, Nathalie; Marcello, Marco; Demicheva, Elena; Hu, Jun-Hao; Hartenstein, Bettina; Augustin, Hellmut G.; Hecker, Markus; Angel, Peter; Korff, Thomas; Schorpp-Kistner, Marina

    2010-01-01

    Cellular contractility and, thus, the ability to alter cell shape are prerequisites for a number of important biological processes such as cytokinesis, movement, differentiation, and substrate adherence. The contractile capacity of vascular smooth muscle cells (VSMCs) is pivotal for the regulation of vascular tone and thus blood pressure and flow. Here, we report that conditional ablation of the transcriptional regulator Junb results in impaired arterial contractility in vivo and in vitro. This was exemplified by resistance of Junb-deficient mice to DOCA-salt–induced volume-dependent hypertension as well as by a decreased contractile capacity of isolated arteries. Detailed analyses of Junb-deficient VSMCs, mouse embryonic fibroblasts, and endothelial cells revealed a general failure in stress fiber formation and impaired cellular motility. Concomitantly, we identified myosin regulatory light chain 9 (Myl9), which is critically involved in actomyosin contractility and stress fiber assembly, as a Junb target. Consistent with these findings, reexpression of either Junb or Myl9 in Junb-deficient cells restored stress fiber formation, cellular motility, and contractile capacity. Our data establish a molecular link between the activator protein–1 transcription factor subunit Junb and actomyosin-based cellular motility as well as cellular and vascular contractility by governing Myl9 transcription. PMID:20551518

  15. 34 CFR Appendix E to Part 300 - Index for IDEA-Part B Regulations (34 CFR Part 300)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 2 2010-07-01 2010-07-01 false Index for IDEA-Part B Regulations (34 CFR Part 300) E... B Regulations (34 CFR Part 300) ACCESS TO • Access rights (Parents) 300.613. • Assistive technology... 300.8(c)(6). • Multiple disabilities 300.8(c)(7). • Native language 300.29(a). • Occupational...

  16. 34 CFR Appendix E to Part 300 - Index for IDEA-Part B Regulations (34 CFR Part 300)

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 2 2011-07-01 2010-07-01 true Index for IDEA-Part B Regulations (34 CFR Part 300) E... B Regulations (34 CFR Part 300) ACCESS TO • Access rights (Parents) 300.613. • Assistive technology... “Limited English proficient”) LEUKEMIA (Other health impairment) 300.8(c)(9)(i). LIMITED ENGLISH...

  17. 34 CFR Appendix E to Part 300 - Index for IDEA-Part B Regulations (34 CFR Part 300)

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 2 2012-07-01 2012-07-01 false Index for IDEA-Part B Regulations (34 CFR Part 300) E... B Regulations (34 CFR Part 300) ACCESS TO • Access rights (Parents) 300.613. • Assistive technology... “Limited English proficient”) LEUKEMIA (Other health impairment) 300.8(c)(9)(i). LIMITED ENGLISH...

  18. 34 CFR Appendix E to Part 300 - Index for IDEA-Part B Regulations (34 CFR Part 300)

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 2 2014-07-01 2013-07-01 true Index for IDEA-Part B Regulations (34 CFR Part 300) E... B Regulations (34 CFR Part 300) ACCESS TO • Access rights (Parents) 300.613. • Assistive technology...). • Protections for children not determined eligible 300.534. • Secretaries of the Interior and Health and...

  19. 34 CFR Appendix E to Part 300 - Index for IDEA-Part B Regulations (34 CFR Part 300)

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 2 2013-07-01 2013-07-01 false Index for IDEA-Part B Regulations (34 CFR Part 300) E Appendix E to Part 300 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF SPECIAL EDUCATION AND REHABILITATIVE SERVICES, DEPARTMENT OF EDUCATION ASSISTANCE TO STATES FOR THE EDUCATION OF CHILDREN...

  20. Dancing with the regulations - Part Deux

    SciTech Connect

    Nitschke, R.L.

    1995-12-31

    The disposal of low-level radioactive waste (LLW) in the United States has long been subjected to two very similar regulations depending upon the location. Disposal sites located on Department of Energy (DOE) Reservations are subject to DOE Order 5820.2A {open_quotes}Radioactive Waste Management,{close_quotes} while disposal sites located elsewhere are subject to the Nuclear Regulatory Commission regulation 10 CFR 61 {open_quotes}Licensing Requirements for Land Disposal of Radioactive Waste.{close_quotes} While life was not necessarily good, there was only one sheet of music to dance to. Recently a new player, named CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act), has ridden into those DOE towns, and for those whose disposal facilities lie within or adjacent to Superfund sites, she has brought along a different drum to dance to. This paper discusses the differences and similarities between the different dance partners and their associated musical scores (i.e., the performance assessment (PA) required by the DOE order and the baseline risk assessment (BRA) required by CERCLA). The paper then provides a brief discussion on the latest dancer to cut in: the Defense Nuclear Facilities Safety Board (DNFSB). This discussion should help to alleviate the confusion while dancing on the LLW disposal regulatory ballroom floor.

  1. Oxidative stress in the haematopoietic niche regulates the cellular immune response in Drosophila.

    PubMed

    Sinenko, Sergey A; Shim, Jiwon; Banerjee, Utpal

    2012-01-01

    Oxidative stress induced by high levels of reactive oxygen species (ROS) is associated with the development of different pathological conditions, including cancers and autoimmune diseases. We analysed whether oxidatively challenged tissue can have systemic effects on the development of cellular immune responses using Drosophila as a model system. Indeed, the haematopoietic niche that normally maintains blood progenitors can sense oxidative stress and regulate the cellular immune response. Pathogen infection induces ROS in the niche cells, resulting in the secretion of an epidermal growth factor-like cytokine signal that leads to the differentiation of specialized cells involved in innate immune responses. PMID:22134547

  2. TMEM55B is a Novel Regulator of Cellular Cholesterol Metabolism

    PubMed Central

    Medina, Marisa W.; Bauzon, Frederick; Naidoo, Devesh; Theusch, Elizabeth; Stevens, Kristen; Schilde, Jessica; Schubert, Christian; Mangravite, Lara M.; Rudel, Lawrence L.; Temel, Ryan E.; Runz, Heiko; Krauss, Ronald M.

    2014-01-01

    Objective Inter-individual variation in pathways impacting cellular cholesterol metabolism can influence levels of plasma cholesterol, a well-established risk factor for cardiovascular disease. Inherent variation among immortalized lymphoblastoid cell lines (LCLs) from different donors can be leveraged to discover novel genes that modulate cellular cholesterol metabolism. The objective of this study was to identify novel genes that regulate cholesterol metabolism by testing for evidence of correlated gene expression with cellular levels of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) mRNA, a marker for cellular cholesterol homeostasis, in a large panel of LCLs. Approach and Results Expression array profiling was performed on 480 LCLs established from participants of the Cholesterol and Pharmacogenetics statin clinical trial, and transcripts were tested for evidence of correlated expression with HMGCR as a marker of intracellular cholesterol homeostasis. Of these, transmembrane protein 55b (TMEM55B) showed the strongest correlation (r=0.29, p=4.0E-08) of all genes not previously implicated in cholesterol metabolism and was found to be sterol regulated. TMEM55B knock-down in human hepatoma cell lines promoted the decay rate of the low density lipoprotein receptor (LDLR), reduced cell surface LDLR protein, impaired LDL uptake, and reduced intracellular cholesterol. Conclusions Here we report identification of TMEM55B as a novel regulator of cellular cholesterol metabolism through the combination of gene expression profiling and functional studies. The findings highlight the value of an integrated genomic approach for identifying genes that influence cholesterol homeostasis. PMID:25035345

  3. The Relevance of JAK2 in the Regulation of Cellular Transport.

    PubMed

    Sopjani, Mentor; Konjufca, Vjollca; Rinnerthaler, Mark; Rexhepaj, Rexhep; Dërmaku-Sopjani, Miribane

    2016-01-01

    Janus kinase-2 (JAK2) is a non-receptor tyrosine kinase signaling molecule that mediates the effects of various hormones and cytokines, including interferon, erythropoietin, leptin, and growth hormone. It also fosters tumor growth and modifies the activity of several nutrient transporters. JAK2 contributes to the regulation of the cell volume, protectS cells during energy depletion, proliferation, and aids the survival of tumor cells. Recently, JAK2 was identified as a powerful regulator of transport processes across the plasma membrane. Either directly or indirectly JAK2 may stimulate or inhibit transporter proteins, including ion channels, carriers and Na(+)/K(+) pumps. As a powerful regulator of transport mechanisms across the cell membrane, JAK2 regulates a wide variety of potassium, calcium, sodium and chloride ion channels, multiple Na+-coupled cellular carriers including EAAT1-4, NaPi-IIa, SGLT1, BoaT1, PepT1-2, CreaT1, SMIT1, and BGT1 as well as Na(+)/K(+)-ATPase. These cellular transport regulations contribute to various physiological and pathophysiological processes and thus exerting JAK2-sensitive effects. Future investigations will be important to determine whether JAK2 regulates cell-surface expression of other transporters and further elucidate underlying mechanisms governing JAK2 actions. PMID:26639094

  4. FIH Regulates Cellular Metabolism through Hydroxylation of the Deubiquitinase OTUB1

    PubMed Central

    Scholz, Carsten C.; Rodriguez, Javier; Pickel, Christina; Burr, Stephen; Fabrizio, Jacqueline-alba; Nolan, Karen A.; Spielmann, Patrick; Cavadas, Miguel A. S.; Crifo, Bianca; Halligan, Doug N.; Nathan, James A.; Peet, Daniel J.; Wenger, Roland H.; Von Kriegsheim, Alex; Cummins, Eoin P.; Taylor, Cormac T.

    2016-01-01

    The asparagine hydroxylase, factor inhibiting HIF (FIH), confers oxygen-dependence upon the hypoxia-inducible factor (HIF), a master regulator of the cellular adaptive response to hypoxia. Studies investigating whether asparagine hydroxylation is a general regulatory oxygen-dependent modification have identified multiple non-HIF targets for FIH. However, the functional consequences of this outside of the HIF pathway remain unclear. Here, we demonstrate that the deubiquitinase ovarian tumor domain containing ubiquitin aldehyde binding protein 1 (OTUB1) is a substrate for hydroxylation by FIH on N22. Mutation of N22 leads to a profound change in the interaction of OTUB1 with proteins important in cellular metabolism. Furthermore, in cultured cells, overexpression of N22A mutant OTUB1 impairs cellular metabolic processes when compared to wild type. Based on these data, we hypothesize that OTUB1 is a target for functional hydroxylation by FIH. Additionally, we propose that our results provide new insight into the regulation of cellular energy metabolism during hypoxic stress and the potential for targeting hydroxylases for therapeutic benefit. PMID:26752685

  5. Cellular electrical micro-impedance parameter artifacts produced by passive and active current regulation.

    PubMed

    English, Anthony E; Squire, James C; Moy, Alan B

    2008-03-01

    This study analyzes the cellular microelectrode voltage measurement errors produced by active and passive current regulation, and the propagation of these errors into cellular barrier function parameter estimates. The propagation of random and systematic errors into these parameters is accounted for within a Riemannian manifold framework consistent with information geometry. As a result, the full non-linearity of the model parameter state dependence, the instrumental noise distribution, and the systematic errors associated with the voltage to impedance conversion, are accounted for. Specifically, cellular model parameters are treated as the coordinates of a model space manifold that inherits a Riemannian metric from the data space. The model space metric is defined in terms of the pull back of an instrumental noise-dependent Fisher information metric. Additional noise sources produced by the evaluation of the cell-covered electrode model that is a function of a naked electrode random variable are also included in the analysis. Based on a circular cellular micro-impedance model in widespread use, this study shows that cellular barrier function parameter estimates are highly model state dependent. Systematic errors produced by coaxial lead capacitances and circuit loading can also lead to significant and model state-dependent parameter errors and should, therefore, be either reduced or corrected for analytically. PMID:18202917

  6. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  7. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  8. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  9. 47 CFR 22.877 - Unacceptable interference to part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  10. 47 CFR 22.877 - Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-cellular 800 MHz licensees from commercial aviation air-ground systems. 22.877 Section 22.877...-Ground Radiotelephone Service Commercial Aviation Air-Ground Systems § 22.877 Unacceptable interference to Part 90 non-cellular 800 MHz licensees from commercial aviation air-ground systems. The...

  11. Roles and regulation of Neutral Sphingomyelinase-2 in cellular and pathological processes

    PubMed Central

    Shamseddine, Achraf A.; Airola, Michael V.; Hannun, Yusuf A.

    2015-01-01

    Our understanding of the functions of ceramide signaling has advanced tremendously over the past decade. In this review, we focus on the roles and regulation of neutral sphingomyelinase 2 (nSMase2), an enzyme that generates the bioactive lipid ceramide through the hydrolysis of the membrane lipid sphingomyelin. A large body of work has now implicated nSMase2 in a diverse set of cellular functions, physiological processes, and disease pathologies. We discuss different aspects of this enzyme’s regulation from transcriptional, post-translational, and biochemical. Furthermore, we highlight nSMase2 involvement in cellular processes including inflammatory signaling, exosome generation, cell growth, and apoptosis, which in turn play important roles in pathologies such as cancer metastasis, Alzheimer’s disease, and other organ systems disorders. Lastly, we examine avenues where targeted nSMase2-inhibition may be clinically beneficial in disease scenarios. PMID:25465297

  12. Roles and regulation of neutral sphingomyelinase-2 in cellular and pathological processes.

    PubMed

    Shamseddine, Achraf A; Airola, Michael V; Hannun, Yusuf A

    2015-01-01

    Our understanding of the functions of ceramide signaling has advanced tremendously over the past decade. In this review, we focus on the roles and regulation of neutral sphingomyelinase 2 (nSMase2), an enzyme that generates the bioactive lipid ceramide through the hydrolysis of the membrane lipid sphingomyelin. A large body of work has now implicated nSMase2 in a diverse set of cellular functions, physiological processes, and disease pathologies. We discuss different aspects of this enzyme's regulation from transcriptional, post-translational, and biochemical. Furthermore, we highlight nSMase2 involvement in cellular processes including inflammatory signaling, exosome generation, cell growth, and apoptosis, which in turn play important roles in pathologies such as cancer metastasis, Alzheimer's disease, and other organ systems disorders. Lastly, we examine avenues where targeted nSMase2-inhibition may be clinically beneficial in disease scenarios. PMID:25465297

  13. Unveiling the principle of microRNA-mediated redundancy in cellular pathway regulation

    PubMed Central

    Fischer, Simon; Handrick, René; Aschrafi, Armaz; Otte, Kerstin

    2015-01-01

    Understanding the multifaceted nature of microRNA (miRNA) function in mammalian cells is still a challenge. Commonly accepted principles of cooperativity and multiplicity of miRNA function imply that individual mRNAs can be targeted by several miRNAs whereas a single miRNA may concomitantly regulate a subset of different genes. However, there is a paucity of information whether multiple miRNAs regulate critical cellular events and thereby acting redundantly. To gain insight into this notion, we conducted an unbiased high-content miRNA screen by individually introducing 1139 miRNA mimics into Chinese hamster ovary (CHO) cells. We discovered that 66% of all miRNAs significantly impacted on proliferation, protein expression, apoptosis and necrosis. In summary, we provide evidence for a substantial degree of redundancy among miRNAs to maintain cellular homeostasis. PMID:25826657

  14. The Regulation of Cellular Responses to Mechanical Cues by Rho GTPases

    PubMed Central

    Hoon, Jing Ling; Tan, Mei Hua; Koh, Cheng-Gee

    2016-01-01

    The Rho GTPases regulate many cellular signaling cascades that modulate cell motility, migration, morphology and cell division. A large body of work has now delineated the biochemical cues and pathways, which stimulate the GTPases and their downstream effectors. However, cells also respond exquisitely to biophysical and mechanical cues such as stiffness and topography of the extracellular matrix that profoundly influence cell migration, proliferation and differentiation. As these cellular responses are mediated by the actin cytoskeleton, an involvement of Rho GTPases in the transduction of such cues is not unexpected. In this review, we discuss an emerging role of Rho GTPase proteins in the regulation of the responses elicited by biophysical and mechanical stimuli. PMID:27058559

  15. Mechanisms in photodynamic therapy: part two—cellular signaling, cell metabolism and modes of cell death

    PubMed Central

    Castano, Ana P.; Demidova, Tatiana N.; Hamblin, Michael R.

    2013-01-01

    Summary Photodynamic therapy (PDT) has been known for over a hundred years, but is only now becoming widely used. Originally developed as a tumor therapy, some of its most successful applications are for non-malignant disease. In the second of a series of three reviews, we will discuss the mechanisms that operate in PDT on a cellular level. In Part I [Castano AP, Demidova TN, Hamblin MR. Mechanism in photodynamic therapy: part one—photosensitizers, photochemistry and cellular localization. Photodiagn Photodyn Ther 2004;1:279–93] it was shown that one of the most important factors governing the outcome of PDT, is how the photosensitizer (PS) interacts with cells in the target tissue or tumor, and the key aspect of this interaction is the subcellular localization of the PS. PS can localize in mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes. An explosion of investigation and explorations in the field of cell biology have elucidated many of the pathways that mammalian cells undergo when PS are delivered in tissue culture and subsequently illuminated. There is an acute stress response leading to changes in calcium and lipid metabolism and production of cytokines and stress proteins. Enzymes particularly, protein kinases, are activated and transcription factors are expressed. Many of the cellular responses are centered on mitochondria. These effects frequently lead to induction of apoptosis either by the mitochondrial pathway involving caspases and release of cytochrome c, or by pathways involving ceramide or death receptors. However, under certain circumstances cells subjected to PDT die by necrosis. Although there have been many reports of DNA damage caused by PDT, this is not thought to be an important cell-death pathway. This mechanistic research is expected to lead to optimization of PDT as a tumor treatment, and to rational selection of combination therapies that include PDT as a component. PMID:25048553

  16. Removal of Regulations. Final Regulations. Federal Register, Department of Education, 34 CFR Part 345

    ERIC Educational Resources Information Center

    National Archives and Records Administration, 2004

    2004-01-01

    The Secretary amends the Code of Federal Regulations (CFR) to remove obsolete regulations. As a result of the enactment of the Assistive Technology Act of 1998, these regulations are no longer needed. The Secretary therefore takes this action to remove the regulations. Part 345 is removed effective March 25, 2004.

  17. Cellular and physiological mechanisms underlying blood flow regulation in the retina choroid in health disease

    PubMed Central

    Kur, Joanna; Newman, Eric A.; Chan-Ling, Tailoi

    2012-01-01

    We review the cellular and physiological mechanisms responsible for the regulation of blood flow in the retina and choroid in health and disease. Due to the intrinsic light sensitivity of the retina and the direct visual accessibility of fundus blood vessels, the eye offers unique opportunities for the non-invasive investigation of mechanisms of blood flow regulation. The ability of the retinal vasculature to regulate its blood flow is contrasted with the far more restricted ability of the choroidal circulation to regulate its blood flow by virtue of the absence of glial cells, the markedly reduced pericyte ensheathment of the choroidal vasculature, and the lack of intermediate filaments in choroidal pericytes. We review the cellular and molecular components of the neurovascular unit in the retina and choroid, techniques for monitoring retinal and choroidal blood flow, responses of the retinal and choroidal circulation to light stimulation, the role of capillaries, astrocytes and pericytes in regulating blood flow, putative signaling mechanisms mediating neurovascular coupling in the retina, and changes that occur in the retinal and choroidal circulation during diabetic retinopathy, age-related macular degeneration, glaucoma, and Alzheimer's disease. We close by discussing issues that remain to be explored. PMID:22580107

  18. Experimental and computational assessment of F-actin influence in regulating cellular stiffness and relaxation behaviour of fibroblasts.

    PubMed

    Fallqvist, Björn; Fielden, Matthew L; Pettersson, Torbjörn; Nordgren, Niklas; Kroon, Martin; Gad, Annica K B

    2016-06-01

    In biomechanics, a complete understanding of the structures and mechanisms that regulate cellular stiffness at a molecular level remain elusive. In this paper, we have elucidated the role of filamentous actin (F-actin) in regulating elastic and viscous properties of the cytoplasm and the nucleus. Specifically, we performed colloidal-probe atomic force microscopy (AFM) on BjhTERT fibroblast cells incubated with Latrunculin B (LatB), which results in depolymerisation of F-actin, or DMSO control. We found that the treatment with LatB not only reduced cellular stiffness, but also greatly increased the relaxation rate for the cytoplasm in the peripheral region and in the vicinity of the nucleus. We thus conclude that F-actin is a major determinant in not only providing elastic stiffness to the cell, but also in regulating its viscous behaviour. To further investigate the interdependence of different cytoskeletal networks and cell shape, we provided a computational model in a finite element framework. The computational model is based on a split strain energy function of separate cellular constituents, here assumed to be cytoskeletal components, for which a composite strain energy function was defined. We found a significant influence of cell geometry on the predicted mechanical response. Importantly, the relaxation behaviour of the cell can be characterised by a material model with two time constants that have previously been found to predict mechanical behaviour of actin and intermediate filament networks. By merely tuning two effective stiffness parameters, the model predicts experimental results in cells with a partly depolymerised actin cytoskeleton as well as in untreated control. This indicates that actin and intermediate filament networks are instrumental in providing elastic stiffness in response to applied forces, as well as governing the relaxation behaviour over shorter and longer time-scales, respectively. PMID:26766328

  19. AMP-activated protein kinase regulates L-arginine mediated cellular responses

    PubMed Central

    2013-01-01

    Background Our prior study revealed the loss in short-term L-Arginine (ARG) therapeutic efficacy after continuous exposure; resulting in tolerance development, mediated by endothelial nitric oxide synthase (eNOS) down-regulation, secondary to oxidative stress and induced glucose accumulation. However, the potential factor regulating ARG cellular response is presently unknown. Method Human umbilical vein endothelial cells were incubated with 100 μM ARG for 2 h in buffer (short-term or acute), or for 7 days in culture medium and challenged for 2 h in buffer (continuous or chronic), in the presence or absence of other agents. eNOS activity was determined by analyzing cellular nitrite/nitrate (NO2–/NO3–), and AMP-activated protein kinase (AMPK) activity was assayed using SAMS peptide. 13C6 glucose was added to medium to measure glucose uptake during cellular treatments, which were determined by LC-MS/MS. Cellular glucose was identified by o-toluidine method. Superoxide (O2•–) was identified by EPR-spin-trap, and peroxynitrite (ONOO–) was measured by flow-cytometer using aminophenyl fluorescein dye. Results Short-term incubation of cells with 100 μM ARG in the presence or absence of 30 μM L-NG-Nitroarginine methyl ester (L-NAME) or 30 μM AMPK inhibitor (compound C, CMP-C) increased cellular oxidative stress and overall glucose accumulation with no variation in glucose transporter-1 (GLUT-1), or AMPK activity from control. The increase in total NO2–/NO3– after 2 h 100 μM ARG exposure, was suppressed in cells co-incubated with 30 μM CMP-C or L-NAME. Long-term exposure of ARG with or without CMP-C or L-NAME suppressed NO2–/NO3–, glucose uptake, GLUT-1, AMPK expression and activity below control, and increased overall cellular glucose, O2•– and ONOO–. Gluconeogenesis inhibition with 30 μM 5-Chloro-2-N-2,5-dichlorobenzenesulfonamido-benzoxazole (CDB) during ARG exposure for 2 h maintained overall cellular glucose to control, but increased

  20. 75 FR 70217 - Defense Transportation Regulation, Part IV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-17

    ... Register April 1, 2010 (75 FR 16445-16446). The interim response and disposition of comments can be viewed on the USTRANSCOM Web site (under misc) at http://www.transcom.mil/dtr/part-iv/misc.cfm . Additional... of the Secretary Defense Transportation Regulation, Part IV AGENCY: United States...

  1. Regulation of p53 expression, phosphorylation and sub-cellular localisation by a G-protein coupled receptor

    PubMed Central

    Solyakov, Lev; Sayan, Emre; Riley, Joan; Pointon, Amy; Tobin, Andrew B

    2009-01-01

    G-protein coupled receptors (GPCRs) have been extremely successful drug targets for a multitude of diseases from heart failure to depression. This super-family of cell surface receptors have not, however, been widely considered as a viable target in cancer treatment. In the current study we demonstrate that a classical Gq/11-coupled GPCR, the M3-muscarinic receptor, was able to regulate apoptosis via receptors that are endogenously expressed in the human neuroblastoma cell line SH-SY5Y and when ectopically expressed in Chinese hamster ovary (CHO) cells. Stimulation of the M3-muscarinic receptor was shown to inhibit the ability of the DNA-damaging chemotherapeutic agent, etoposide, from mediating apoptosis. This protective response in CHO cells correlated with the ability of the receptor to regulate the expression levels of p53. In contrast, stimulation of endogenous muscarinic receptors in SH-SY5Y cells did not regulate p53 expression but rather was able to inhibit p53 translocation to the mitochondria and p53 phosphorylation at serine 15 and 37. This study suggests the possibility that a GPCR can regulate the apoptotic properties of a chemotherapeutic DNA-damaging agent by regulating the expression, sub-cellular trafficking and modification of p53 in a manner that is in part dependent on the cell type. PMID:19648965

  2. Nanostructures of Designed Geometry and Functionality Enable Regulation of Cellular Signaling Processes

    PubMed Central

    Li, Jie-Ren; Shi, Lifang; Deng, Zhao; Lo, Su Hao; Liu, Gang-yu

    2014-01-01

    Extracellular matrices (ECM) triggered cellular signaling processes often begin with the clustering of the cellular receptors such as integrin and FcεRI. The sizes of these initial protein complexes or clusters are tens to 100 nm in dimension; therefore, engineered nanostructures could provide effective mimics of ECM for investigation and control of the initial and downstream specific signaling process. This current topic discusses recent advances in nanotechnology in the context of design and production of matching chemical functionality and geometry for control of specific cellular signaling processes. Two investigations are reported to demonstrate this concept: (a) how the presentation of antigen at nanometer scale would influence the aggregation of FcεRI, which would impact the formation of activation complexes, leading to rearrangement of actin in cytoskeleton and degranulation or activation of mast cells; (b) how the engineered nanostructure could guide the initial integrin clustering, which would impact the formation of focal adhesion and downstream cell signaling cascades, leading to polarization, migration and morphological changes. Complimentary to engineered ECMs using synthetic ligands or peptides, or topographic control at micrometer scale, nanostructures of designed geometry and chemical functionality provide new and effective biochemical cues for regulation of cellular signaling processes and downstream behaviors. PMID:22783801

  3. Salt-Induced Electrospun Patterned Bundled Fibers for Spatially Regulating Cellular Responses.

    PubMed

    Cho, Mira; Kim, Seung-Hyun; Jin, Gyuhyung; Park, Kook In; Jang, Jae-Hyung

    2016-06-01

    Implementing patterned fibrous matrices can offer a highly valuable platform for spatially orchestrating hierarchical cellular constructs, specifically for neural engineering approaches, in which striated alignment or directional growth of axons are key elements for the functional recovery of damaged nervous systems. Thus, understanding the structural parameters of patterned fibrous matrices that can effectively promote neural growth can provide crucial clues for designing state-of-the-art tissue engineering scaffolds. To this end, salt-induced electrospun patterned fiber bundles (SiEP bundles) comprising longitudinally stacked multiple fibers were fabricated, and their capabilities of spatially stimulating the responses of neural cells, including PC12 cells, human neural stem cells (hNSCs), and dorsal root ganglia (DRG), were assessed by comparing them to conventional fibrous matrices having either randomly oriented fibers or individually aligned fibers. The SiEP bundles possessed remarkably distinctive morphological and topographical characteristics: multicomplexed infrastructures with nano- and microscale fibers, rough surfaces, and soft mechanical properties. Importantly, the SiEP bundles resulted in spatial cellular elongations corresponding to the fiber directions and induced highly robust neurite extensions along the patterned fibers. Furthermore, the residence of hNSCs on the topographically rough grooves of the SiEP bundles boosted neuronal differentiation. These findings can provide crucial insights for designing fibrous platforms that can spatially regulate cellular responses and potentially offer powerful strategies for a neural growth system in which directional cellular responses are critical for the functional recovery of damaged neural tissues. PMID:27167566

  4. DPY30 regulates pathways in cellular senescence through ID protein expression

    PubMed Central

    Simboeck, Elisabeth; Gutierrez, Arantxa; Cozzuto, Luca; Beringer, Malte; Caizzi, Livia; M Keyes, William; Di Croce, Luciano

    2013-01-01

    Cellular senescence is an intrinsic defense mechanism to various cellular stresses: while still metabolically active, senescent cells stop dividing and enter a proliferation arrest. Here, we identify DPY30, a member of all mammalian histone H3K4 histone methyltransferases (HMTases), as a key regulator of the proliferation potential of human primary cells. Following depletion of DPY30, cells show a severe proliferation defect and display a senescent phenotype, including a flattened and enlarged morphology, elevated level of reactive oxygen species (ROS), increased SA-β-galactosidase activity, and formation of senescence-associated heterochromatin foci (SAHFs). While DPY30 depletion leads to a reduced level of H3K4me3-marked active chromatin, we observed a concomitant activation of CDK inhibitors, including p16INK4a, independent of H3K4me3. ChIP experiments show that key regulators of cell-cycle progression, including ID proteins, are under direct control of DPY30. Because ID proteins are negative regulators of the transcription factors ETS1/2, depletion of DPY30 leads to the transcriptional activation of p16INK4a by ETS1/2 and thus to a senescent-like phenotype. Ectoptic re-introduction of ID protein expression can partially rescue the senescence-like phenotype induced by DPY30 depletion. Thus, our data indicate that DPY30 controls proliferation by regulating ID proteins expression, which in turn lead to senescence bypass. PMID:23872946

  5. Posttranscriptional regulation of cellular gene expression by the c-myc oncogene

    SciTech Connect

    Prendergast, G.C.; Cole, M.D. . Dept. of Biology)

    1989-01-01

    The c-myc oncogene has been implicated in the development of many different cancers, yet the mechanism by which the c-myc protein alters cellular growth control has proven elusive. The authors used a cDNA hybridization difference assay to isolate two genes, mr1 and mr2, that were constitutively expressed (i.e., deregulated) in rodent fibroblast cell lines immortalized by transfection of a viral promoter-linked c-myc gene. Both cDNAs were serum inducible in quiescent G/sub o/ fibroblasts, suggesting that they are functionally related to cellular proliferative processes. Although there were significant differences in cytoplasmic mRNA levels between myc-immortalized and control cells, the rates of transcription and mRNA turnover of both genes were similar, suggesting that c-myc regulates mr1 and mr2 expression by some nuclear posttranscriptional mechanism. Their results provide evidence that c-myc can rapidly modulate cellular gene expression and suggest that c-myc may function in gene regulation at the level of RNA export, splicing, or nuclear RNA turnover.

  6. Stem-loop binding protein is a multifaceted cellular regulator of HIV-1 replication.

    PubMed

    Li, Ming; Tucker, Lynne D; Asara, John M; Cheruiyot, Collins K; Lu, Huafei; Wu, Zhijin J; Newstein, Michael C; Dooner, Mark S; Friedman, Jennifer; Lally, Michelle A; Ramratnam, Bharat

    2016-08-01

    A rare subset of HIV-1-infected individuals is able to maintain plasma viral load (VL) at low levels without antiretroviral treatment. Identifying the mechanisms underlying this atypical response to infection may lead to therapeutic advances for treating HIV-1. Here, we developed a proteomic analysis to compare peripheral blood cell proteomes in 20 HIV-1-infected individuals who maintained either high or low VL with the aim of identifying host factors that impact HIV-1 replication. We determined that the levels of multiple histone proteins were markedly decreased in cohorts of individuals with high VL. This reduction was correlated with lower levels of stem-loop binding protein (SLBP), which is known to control histone metabolism. Depletion of cellular SLBP increased promoter engagement with the chromatin structures of the host gene high mobility group protein A1 (HMGA1) and viral long terminal repeat (LTR), which led to higher levels of HIV-1 genomic integration and proviral transcription. Further, we determined that TNF-α regulates expression of SLBP and observed that plasma TNF-α levels in HIV-1-infected individuals correlated directly with VL levels and inversely with cellular SLBP levels. Our findings identify SLBP as a potentially important cellular regulator of HIV-1, thereby establishing a link between histone metabolism, inflammation, and HIV-1 infection. PMID:27454292

  7. Insulin as the main regulator of cellular glucose utilization--aetiological aspects of insulin resistance.

    PubMed

    Tatoń, Jan; Czech, Anna; Piatkiewicz, Paweł

    2010-01-01

    This review presents the advances in the molecular biology and the pathophysiology of insulin resistance with emphasis on disturbances in cellular glucose transport. New scientific information about the structure and function of glucotransporters from the GLUT4 and SLGT families underline their significance in endocrinopathies and metabolic disease pathogenesis as related to insulin resistance. The new discoveries in this area also contribute to a better understanding of the regulation of insulin receptor and post-receptor reactivity by hormones and by drugs. They refer to the regulation of glycaemia and to its disturbances in diabetes mellitus, particularly of type 2, to metabolic syndrome, and, in general, to the pathogenesis of many syndromes and clinical disturbances caused by insulin resistance. Impairment of cellular glucose transport may be one of the primary aetiological factors in this respect. Therefore, studies of cellular glucotransporters expression and function promise new clinical and pharmacotherapeutic developments. Progress in this area has already been transformed into many practical proposals which are improving clinical practice. PMID:20806184

  8. GIT1 Phosphorylation on Serine 46 by PKD3 Regulates Paxillin Trafficking and Cellular Protrusive Activity*

    PubMed Central

    Huck, Bettina; Kemkemer, Ralf; Franz-Wachtel, Mirita; Macek, Boris; Hausser, Angelika; Olayioye, Monilola A.

    2012-01-01

    The continuous assembly and disassembly of focal adhesions is required for efficient cell spreading and migration. The G-protein-coupled receptor kinase-interacting protein 1 (GIT1) is a multidomain protein whose dynamic localization to sites of cytoskeletal remodeling is critically involved in the regulation of these processes. Here we provide evidence that the subcellular localization of GIT1 is regulated by protein kinase D3 (PKD3) through direct phosphorylation on serine 46. GIT1 phosphorylation on serine 46 was abrograted by PKD3 depletion, thereby identifying GIT1 as the first specific substrate for this kinase. A GIT1 S46D phosphomimetic mutant localized to motile, paxillin-positive cytoplasmic complexes, whereas the phosphorylation-deficient GIT1 S46A was enriched in focal adhesions. We propose that phosphorylation of GIT1 on serine 46 by PKD3 represents a molecular switch by which GIT1 localization, paxillin trafficking, and cellular protrusive activity are regulated. PMID:22893698

  9. Disruption of a cystine transporter downregulates expression of genes involved in sulfur regulation and cellular respiration.

    PubMed

    Simpkins, Jessica A; Rickel, Kirby E; Madeo, Marianna; Ahlers, Bethany A; Carlisle, Gabriel B; Nelson, Heidi J; Cardillo, Andrew L; Weber, Emily A; Vitiello, Peter F; Pearce, David A; Vitiello, Seasson P

    2016-01-01

    Cystine and cysteine are important molecules for pathways such as redox signaling and regulation, and thus identifying cellular deficits upon deletion of the Saccharomyces cerevisiae cystine transporter Ers1p allows for a further understanding of cystine homeostasis. Previous complementation studies using the human ortholog suggest yeast Ers1p is a cystine transporter. Human CTNS encodes the protein Cystinosin, a cystine transporter that is embedded in the lysosomal membrane and facilitates the export of cystine from the lysosome. When CTNS is mutated, cystine transport is disrupted, leading to cystine accumulation, the diagnostic hallmark of the lysosomal storage disorder cystinosis. Here, we provide biochemical evidence for Ers1p-dependent cystine transport. However, the accumulation of intracellular cystine is not observed when the ERS1 gene is deleted from ers1-Δ yeast, supporting the existence of modifier genes that provide a mechanism in ers1-Δ yeast that prevents or corrects cystine accumulation. Upon comparison of the transcriptomes of isogenic ERS1+ and ers1-Δ strains of S. cerevisiae by DNA microarray followed by targeted qPCR, sixteen genes were identified as being differentially expressed between the two genotypes. Genes that encode proteins functioning in sulfur regulation, cellular respiration, and general transport were enriched in our screen, demonstrating pleiotropic effects of ers1-Δ. These results give insight into yeast cystine regulation and the multiple, seemingly distal, pathways that involve proper cystine recycling. PMID:27142334

  10. SIRT1 associates with eIF2-alpha and regulates the cellular stress response

    PubMed Central

    Ghosh, Hiyaa Singhee; Reizis, Boris; Robbins, Paul D.

    2011-01-01

    SIRT1 is a NAD+ dependent protein deacetylase known to increase longevity in model organisms. SIRT1 regulates cellular response to oxidative and/or genotoxic stress by regulating proteins such as p53 and FOXO. The eukaryotic initiation factor-2, eIF2, plays a critical role in the integrated stress response pathway. Under cellular stress, phosphorylation of the alpha subunit of eIF2 is essential for immediate shut-off of translation and activation of stress response genes. Here we demonstrate that SIRT1 interacts with eIF2α. Loss of SIRT1 results in increased phosphorylation of eIF2α. However, the downstream stress induced signaling pathway is compromised in SIRT1-deficient cells, indicated by delayed expression of the downstream target genes CHOP and GADD34 and a slower post-stress translation recovery. Finally, SIRT1 co-immunoprecipitates with mediators of eIF2α dephosphorylation, GADD34 and CreP, suggesting a role for SIRT1 in the negative feedback regulation of eIF2α phosphorylation. PMID:22355666

  11. The TATA-binding protein as a regulator of cellular transformation.

    PubMed

    Johnson, Sandra A S; Dubeau, Louis; White, Robert J; Johnson, Deborah L

    2003-01-01

    The TATA-binding protein, TBP, is used by all three RNA polymerases and is therefore central to the process of gene expression. TBP associates with several subsets of proteins, called TATA-binding protein-associated factors (TAFs). This results in the formation of at least three distinct complexes, SL1, TFIID, and TFIIIB, which dictates whether TBP functions in RNA polymerase (pol) I, pol II, or pol III transcription, respectively. The regulation of gene expression has focused largely on proteins that serve to modulate the efficiency by which the general transcription components, such as TBP, interact with promoters. The possibility of a basal transcription factor, itself, being regulated, and influencing cellular homeostasis, has not been extensively considered. However, recent studies have indicated that TBP is indeed regulated, and that modulation of its cellular concentration has a profound, and surprisingly selective, impact on gene expression that can mediate the normal proliferative responses of cells to growth stimuli as well as the transformation potential of cells. PMID:12963838

  12. Disruption of a cystine transporter downregulates expression of genes involved in sulfur regulation and cellular respiration

    PubMed Central

    Simpkins, Jessica A.; Rickel, Kirby E.; Madeo, Marianna; Ahlers, Bethany A.; Carlisle, Gabriel B.; Nelson, Heidi J.; Cardillo, Andrew L.; Weber, Emily A.; Vitiello, Peter F.; Pearce, David A.

    2016-01-01

    ABSTRACT Cystine and cysteine are important molecules for pathways such as redox signaling and regulation, and thus identifying cellular deficits upon deletion of the Saccharomyces cerevisiae cystine transporter Ers1p allows for a further understanding of cystine homeostasis. Previous complementation studies using the human ortholog suggest yeast Ers1p is a cystine transporter. Human CTNS encodes the protein Cystinosin, a cystine transporter that is embedded in the lysosomal membrane and facilitates the export of cystine from the lysosome. When CTNS is mutated, cystine transport is disrupted, leading to cystine accumulation, the diagnostic hallmark of the lysosomal storage disorder cystinosis. Here, we provide biochemical evidence for Ers1p-dependent cystine transport. However, the accumulation of intracellular cystine is not observed when the ERS1 gene is deleted from ers1-Δ yeast, supporting the existence of modifier genes that provide a mechanism in ers1-Δ yeast that prevents or corrects cystine accumulation. Upon comparison of the transcriptomes of isogenic ERS1+ and ers1-Δ strains of S. cerevisiae by DNA microarray followed by targeted qPCR, sixteen genes were identified as being differentially expressed between the two genotypes. Genes that encode proteins functioning in sulfur regulation, cellular respiration, and general transport were enriched in our screen, demonstrating pleiotropic effects of ers1-Δ. These results give insight into yeast cystine regulation and the multiple, seemingly distal, pathways that involve proper cystine recycling. PMID:27142334

  13. Statistical properties of cellular automata in the context of learning and recognition: Part 1, Introduction

    SciTech Connect

    Gutowitz, H.A.

    1988-11-17

    In this lecture the map from a cellular automaton to a sequence of analytical approximations called the local structure theory is described. Connections are drawn between cellular automata and neural network models. It is suggested that the process by which a cellular automaton holds particular probability measures invariant is an appropriate model for biological memory. 20 figs.

  14. The Rho GTPase Cdc42 regulates hair cell planar polarity and cellular patterning in the developing cochlea

    PubMed Central

    Kirjavainen, Anna; Laos, Maarja; Anttonen, Tommi; Pirvola, Ulla

    2015-01-01

    Hair cells of the organ of Corti (OC) of the cochlea exhibit distinct planar polarity, both at the tissue and cellular level. Planar polarity at tissue level is manifested as uniform orientation of the hair cell stereociliary bundles. Hair cell intrinsic polarity is defined as structural hair bundle asymmetry; positioning of the kinocilium/basal body complex at the vertex of the V-shaped bundle. Consistent with strong apical polarity, the hair cell apex displays prominent actin and microtubule cytoskeletons. The Rho GTPase Cdc42 regulates cytoskeletal dynamics and polarization of various cell types, and, thus, serves as a candidate regulator of hair cell polarity. We have here induced Cdc42 inactivation in the late-embryonic OC. We show the role of Cdc42 in the establishment of planar polarity of hair cells and in cellular patterning. Abnormal planar polarity was displayed as disturbances in hair bundle orientation and morphology and in kinocilium/basal body positioning. These defects were accompanied by a disorganized cell-surface microtubule network. Atypical protein kinase C (aPKC), a putative Cdc42 effector, colocalized with Cdc42 at the hair cell apex, and aPKC expression was altered upon Cdc42 depletion. Our data suggest that Cdc42 together with aPKC is part of the machinery establishing hair cell planar polarity and that Cdc42 acts on polarity through the cell-surface microtubule network. The data also suggest that defects in apical polarization are influenced by disturbed cellular patterning in the OC. In addition, our data demonstrates that Cdc42 is required for stereociliogenesis in the immature cochlea. PMID:25770185

  15. BAF180 regulates cellular senescence and hematopoietic stem cell homeostasis through p21.

    PubMed

    Lee, Hyemin; Dai, Fangyan; Zhuang, Li; Xiao, Zhen-Dong; Kim, Jongchan; Zhang, Yilei; Ma, Li; You, M James; Wang, Zhong; Gan, Boyi

    2016-04-12

    BAF180 (also called PBRM1), a subunit of the SWI/SNF complex, plays critical roles in the regulation of chromatin remodeling and gene transcription, and is frequently mutated in several human cancers. However, the role of mammalian BAF180 in tumor suppression and tissue maintenance in vivo remains largely unknown. Here, using a conditional somatic knockout approach, we explored the cellular and organismal functions of BAF180 in mouse. BAF180 deletion in primary mouse embryonic fibroblasts (MEFs) triggers profound cell cycle arrest, premature cellular senescence, without affecting DNA damage response or chromosomal integrity. While somatic deletion of BAF180 in adult mice does not provoke tumor development, BAF180 deficient mice exhibit defects in hematopoietic system characterized by progressive reduction of hematopoietic stem cells (HSCs), defective long-term repopulating potential, and hematopoietic lineage developmental aberrations. BAF180 deletion results in elevated p21 expression in both MEFs and HSCs. Mechanistically, we showed that BAF180 binds to p21 promoter, and BAF180 deletion enhances the binding of modified histones associated with transcriptional activation on p21 promoter. Deletion of p21 rescues cell cycle arrest and premature senescence in BAF180 deficient MEFs, and partially rescues hematopoietic defects in BAF180 deficient mice. Together, our study identifies BAF180 as a critical regulator of cellular senescence and HSC homeostasis, which is at least partially regulated through BAF180-mediated suppression of p21 expression. Our results also suggest that senescence triggered by BAF180 inactivation may serve as a failsafe mechanism to restrain BAF180 deficiency-associated tumor development, providing a conceptual framework to further understand BAF180 function in tumor biology. PMID:26992241

  16. BAF180 regulates cellular senescence and hematopoietic stem cell homeostasis through p21

    PubMed Central

    Lee, Hyemin; Dai, Fangyan; Zhuang, Li; Xiao, Zhen-Dong; Kim, Jongchan; Zhang, Yilei; Ma, Li; You, M. James; Wang, Zhong; Gan, Boyi

    2016-01-01

    BAF180 (also called PBRM1), a subunit of the SWI/SNF complex, plays critical roles in the regulation of chromatin remodeling and gene transcription, and is frequently mutated in several human cancers. However, the role of mammalian BAF180 in tumor suppression and tissue maintenance in vivo remains largely unknown. Here, using a conditional somatic knockout approach, we explored the cellular and organismal functions of BAF180 in mouse. BAF180 deletion in primary mouse embryonic fibroblasts (MEFs) triggers profound cell cycle arrest, premature cellular senescence, without affecting DNA damage response or chromosomal integrity. While somatic deletion of BAF180 in adult mice does not provoke tumor development, BAF180 deficient mice exhibit defects in hematopoietic system characterized by progressive reduction of hematopoietic stem cells (HSCs), defective long-term repopulating potential, and hematopoietic lineage developmental aberrations. BAF180 deletion results in elevated p21 expression in both MEFs and HSCs. Mechanistically, we showed that BAF180 binds to p21 promoter, and BAF180 deletion enhances the binding of modified histones associated with transcriptional activation on p21 promoter. Deletion of p21 rescues cell cycle arrest and premature senescence in BAF180 deficient MEFs, and partially rescues hematopoietic defects in BAF180 deficient mice. Together, our study identifies BAF180 as a critical regulator of cellular senescence and HSC homeostasis, which is at least partially regulated through BAF180-mediated suppression of p21 expression. Our results also suggest that senescence triggered by BAF180 inactivation may serve as a failsafe mechanism to restrain BAF180 deficiency-associated tumor development, providing a conceptual framework to further understand BAF180 function in tumor biology. PMID:26992241

  17. A biphasic endothelial stress-survival mechanism regulates the cellular response to vascular endothelial growth factor A

    SciTech Connect

    Latham, Antony M.; Odell, Adam F.; Mughal, Nadeem A.; Issitt, Theo; Ulyatt, Clare; Walker, John H.; Homer-Vanniasinkam, Shervanthi; Ponnambalam, Sreenivasan

    2012-11-01

    Vascular endothelial growth factor A (VEGF-A) is an essential cytokine that regulates endothelial function and angiogenesis. VEGF-A binding to endothelial receptor tyrosine kinases such as VEGFR1 and VEGFR2 triggers cellular responses including survival, proliferation and new blood vessel sprouting. Increased levels of a soluble VEGFR1 splice variant (sFlt-1) correlate with endothelial dysfunction in pathologies such as pre-eclampsia; however the cellular mechanism(s) underlying the regulation and function of sFlt-1 are unclear. Here, we demonstrate the existence of a biphasic stress response in endothelial cells, using serum deprivation as a model of endothelial dysfunction. The early phase is characterized by a high VEGFR2:sFlt-1 ratio, which is reversed in the late phase. A functional consequence is a short-term increase in VEGF-A-stimulated intracellular signaling. In the late phase, sFlt-1 is secreted and deposited at the extracellular matrix. We hypothesized that under stress, increased endothelial sFlt-1 levels reduce VEGF-A bioavailability: VEGF-A treatment induces sFlt-1 expression at the cell surface and VEGF-A silencing inhibits sFlt-1 anchorage to the extracellular matrix. Treatment with recombinant sFlt-1 inhibits VEGF-A-stimulated in vitro angiogenesis and sFlt-1 silencing enhances this process. In this response, increased VEGFR2 levels are regulated by the phosphatidylinositol-3-kinase and PKB/Akt signaling pathways and increased sFlt-1 levels by the ERK1/2 signaling pathway. We conclude that during serum withdrawal, cellular sensing of environmental stress modulates sFlt-1 and VEGFR2 levels, regulating VEGF-A bioavailability and ensuring cell survival takes precedence over cell proliferation and migration. These findings may underpin an important mechanism contributing to endothelial dysfunction in pathological states. -- Highlights: Black-Right-Pointing-Pointer Endothelial cells mount a stress response under conditions of low serum. Black

  18. Cellular energy stress induces AMPK-mediated regulation of YAP and the Hippo pathway

    PubMed Central

    Mo, Jung-Soon; Meng, Zhipeng; Kim, Young Chul; Park, Hyun Woo; Hansen, Carsten Gram; Kim, Soohyun; Lim, Dae-Sik; Guan, Kun-Liang

    2015-01-01

    YAP (Yes-associated protein) is a transcription co-activator in the Hippo tumor suppressor pathway and controls cell growth, tissue homeostasis, and organ size. YAP is inhibited by the kinase Lats, which phosphorylates YAP to induce its cytoplasmic localization and proteasomal degradation. YAP induces gene expression by binding to the TEAD family transcription factors. Dysregulation of the Hippo-YAP pathway is frequently observed in human cancers. Here we show that cellular energy stress induces YAP phosphorylation, in part due to AMPK-dependent Lats activation, thereby inhibiting YAP activity. Moreover, AMPK directly phosphorylates YAP S94, a residue essential for the interaction with TEAD, thus disrupting the YAP-TEAD interaction. AMPK-induced YAP inhibition can suppress oncogenic transformation of Lats-null cells with high YAP activity. Our study establishes a molecular mechanism and functional significance of AMPK in linking cellular energy status to the Hippo-YAP pathway. PMID:25751140

  19. The raspberry Gene Is Involved in the Regulation of the Cellular Immune Response in Drosophila melanogaster

    PubMed Central

    Kari, Beáta; Csordás, Gábor; Honti, Viktor; Cinege, Gyöngyi; Williams, Michael J.; Andó, István; Kurucz, Éva

    2016-01-01

    Drosophila is an extremely useful model organism for understanding how innate immune mechanisms defend against microbes and parasitoids. Large foreign objects trigger a potent cellular immune response in Drosophila larva. In the case of endoparasitoid wasp eggs, this response includes hemocyte proliferation, lamellocyte differentiation and eventual encapsulation of the egg. The encapsulation reaction involves the attachment and spreading of hemocytes around the egg, which requires cytoskeletal rearrangements, changes in adhesion properties and cell shape, as well as melanization of the capsule. Guanine nucleotide metabolism has an essential role in the regulation of pathways necessary for this encapsulation response. Here, we show that the Drosophila inosine 5'-monophosphate dehydrogenase (IMPDH), encoded by raspberry (ras), is centrally important for a proper cellular immune response against eggs from the parasitoid wasp Leptopilina boulardi. Notably, hemocyte attachment to the egg and subsequent melanization of the capsule are deficient in hypomorphic ras mutant larvae, which results in a compromised cellular immune response and increased survival of the parasitoid. PMID:26942456

  20. The calcium-sensing receptor as a regulator of cellular fate in normal and pathological conditions.

    PubMed

    Diez-Fraile, A; Lammens, T; Benoit, Y; D'Herde, K G M A

    2013-02-01

    The calcium-sensing receptor (CaSR) belongs to the evolutionarily conserved family of plasma membrane G protein-coupled receptors (GPCRs). Early studies identified an essential role for the CaSR in systemic calcium homeostasis through its ability to sense small changes in circulating calcium concentration and to couple this information to intracellular signaling pathways that influence parathyroid hormone secretion. However, the presence of CaSR protein in tissues is not directly involved in regulating mineral ion homeostasis points to a role for the CaSR in other cellular functions including the control of cellular proliferation, differentiation and apoptosis. This position at the crossroads of cellular fate designates the CaSR as an interesting study subject is likely to be involved in a variety of previously unconsidered human pathologies, including cancer, atherosclerosis and Alzheimer's disease. Here, we will review the recent discoveries regarding the relevance of CaSR signaling in development and disease. Furthermore, we will discuss the rational for developing and using CaSR-based therapeutics. PMID:23228129

  1. Influenza virus pathogenicity regulated by host cellular proteases, cytokines and metabolites, and its therapeutic options

    PubMed Central

    KIDO, Hiroshi

    2015-01-01

    Influenza A virus (IAV) causes significant morbidity and mortality. The knowledge gained within the last decade on the pandemic IAV(H1N1)2009 improved our understanding not only of the viral pathogenicity but also the host cellular factors involved in the pathogenicity of multiorgan failure (MOF), such as cellular trypsin-type hemagglutinin (HA0) processing proteases for viral multiplication, cytokine storm, metabolic disorders and energy crisis. The HA processing proteases in the airway and organs for all IAV known to date have been identified. Recently, a new concept on the pathogenicity of MOF, the “influenza virus–cytokine–trypsin” cycle, has been proposed involving up-regulation of trypsin through pro-inflammatory cytokines, and potentiation of viral multiplication in various organs. Furthermore, the relationship between causative factors has been summarized as the “influenza virus–cytokine–trypsin” cycle interconnected with the “metabolic disorders–cytokine” cycle. These cycles provide new treatment concepts for ATP crisis and MOF. This review discusses IAV pathogenicity on cellular proteases, cytokines, metabolites and therapeutic options. PMID:26460316

  2. Anterior Gradient Protein-2 Is a Regulator of Cellular Adhesion in Prostate Cancer

    PubMed Central

    Chanda, Diptiman; Lee, Joo Hyoung; Sawant, Anandi; Hensel, Jonathan A.; Isayeva, Tatyana; Reilly, Stephanie D.; Siegal, Gene P.; Smith, Claire; Grizzle, William; Singh, Raj; Ponnazhagan, Selvarangan

    2014-01-01

    Anterior Gradient Protein (AGR-2) is reported to be over-expressed in many epithelial cancers and promotes metastasis. A clear-cut mechanism for its observed function(s) has not been previously identified. We found significant upregulation of AGR-2 expression in a bone metastatic prostate cancer cell line, PC3, following culturing in bone marrow-conditioned medium. Substantial AGR-2 expression was also confirmed in prostate cancer tissue specimens in patients with bone lesions. By developing stable clones of PC3 cells with varying levels of AGR-2 expression, we identified that abrogation of AGR-2 significantly reduced cellular attachment to fibronectin, collagen I, collagen IV, laminin I and fibrinogen. Loss of cellular adhesion was associated with sharp decrease in the expression of α4, α5, αV, β3 and β4 integrins. Failure to undergo apoptosis following detachment is a hallmark of epithelial cancer metastasis. The AGR-2-silenced PC3 cells showed higher resistance to Tumor necrosis factor-related apoptosis- inducing ligand (TRAIL) induced apoptosis in vitro. This observation was also supported by significantly reduced Caspase-3 expression in AGR-2-silenced PC3 cells, which is a key effector of both extrinsic and intrinsic death signaling pathways. These data suggest that AGR-2 influence prostate cancer metastasis by regulation of cellular adhesion and apoptosis. PMID:24587138

  3. Proposed changes for part N of suggested state regulations

    SciTech Connect

    Paris, R.

    1997-02-01

    This paper discusses proposed changes for Part N regulations regarding naturally occuring radioactive materials. It describes the work of the Commission on NORM of the Conference of Radiation Control Program Directors (CRCPD), toward adjusting the regulations. A set of questions was formulated and a review panel established to address these questions and come back with recommended actions. The panel recommended the distinction that the material being regulated is `Technologically Enhanced Naturally Occurring Radioactive Material` (TENORM). By this they mean `naturally occurring radioactive material not regulated under the Atomic Energy Act (AEA) whose radionuclide concentrations have been increased by or as a result of human practices.` Recommendations also include: using a dose based instead of concentration based standard; refined definition of exemptions from regulations; exclusion of radon from Total Effective Dose Equivalent (TEDE) calculations; provide states flexibility in implementation; inclusion of prospective remedial and operations aspects for TENORM; provision of institutional controls.

  4. Krüppel-like factor 4 negatively regulates cellular antiviral immune response

    PubMed Central

    Luo, Wei-Wei; Lian, Huan; Zhong, Bo; Shu, Hong-Bing; Li, Shu

    2016-01-01

    Viral infection triggers activation of the transcription factors NF-κB and IRF3, which collaborate to induce the expression of type I interferons (IFNs) and elicit innate antiviral response. In this report, we identified Krüppel-like factor 4 (KLF4) as a negative regulator of virus-triggered signaling. Overexpression of KLF4 inhibited virus-induced activation of ISRE and IFN-β promoter in various types of cells, while knockdown of KLF4 potentiated viral infection-triggered induction of IFNB1 and downstream genes and attenuated viral replication. In addition, KLF4 was found to be localized in the cytosol and nucleus, and viral infection promoted the translocation of KLF4 from cytosol to nucleus. Upon virus infection, KLF4 was bound to the promoter of IFNB gene and inhibited the recruitment of IRF3 to the IFNB promoter. Our study thus suggests that KLF4 negatively regulates cellular antiviral response. PMID:25531393

  5. Cellular microRNAs up-regulate transcription via interaction with promoter TATA-box motifs

    PubMed Central

    Zhang, Yijun; Fan, Miaomiao; Zhang, Xue; Huang, Feng; Wu, Kang; Zhang, Junsong; Liu, Jun; Huang, Zhuoqiong; Luo, Haihua; Tao, Liang; Zhang, Hui

    2014-01-01

    The TATA box represents one of the most prevalent core promoters where the pre-initiation complexes (PICs) for gene transcription are assembled. This assembly is crucial for transcription initiation and well regulated. Here we show that some cellular microRNAs (miRNAs) are associated with RNA polymerase II (Pol II) and TATA box-binding protein (TBP) in human peripheral blood mononuclear cells (PBMCs). Among them, let-7i sequence specifically binds to the TATA-box motif of interleukin-2 (IL-2) gene and elevates IL-2 mRNA and protein production in CD4+ T-lymphocytes in vitro and in vivo. Through direct interaction with the TATA-box motif, let-7i facilitates the PIC assembly and transcription initiation of IL-2 promoter. Several other cellular miRNAs, such as mir-138, mir-92a or mir-181d, also enhance the promoter activities via binding to the TATA-box motifs of insulin, calcitonin or c-myc, respectively. In agreement with the finding that an HIV-1–encoded miRNA could enhance viral replication through targeting the viral promoter TATA-box motif, our data demonstrate that the interaction with core transcription machinery is a novel mechanism for miRNAs to regulate gene expression. PMID:25336585

  6. Mitochondrial Ion Channels/Transporters as Sensors and Regulators of Cellular Redox Signaling

    PubMed Central

    Ryu, Shin-Young; Jhun, Bong Sook; Hurst, Stephen

    2014-01-01

    Abstract Significance: Mitochondrial ion channels/transporters and the electron transport chain (ETC) serve as key sensors and regulators for cellular redox signaling, the production of reactive oxygen species (ROS) and nitrogen species (RNS) in mitochondria, and balancing cell survival and death. Although the functional and pharmacological characteristics of mitochondrial ion transport mechanisms have been extensively studied for several decades, the majority of the molecular identities that are responsible for these channels/transporters have remained a mystery until very recently. Recent Advances: Recent breakthrough studies uncovered the molecular identities of the diverse array of major mitochondrial ion channels/transporters, including the mitochondrial Ca2+ uniporter pore, mitochondrial permeability transition pore, and mitochondrial ATP-sensitive K+ channel. This new information enables us to form detailed molecular and functional characterizations of mitochondrial ion channels/transporters and their roles in mitochondrial redox signaling. Critical Issues: Redox-mediated post-translational modifications of mitochondrial ion channels/transporters and ETC serve as key mechanisms for the spatiotemporal control of mitochondrial ROS/RNS generation. Future Directions: Identification of detailed molecular mechanisms for redox-mediated regulation of mitochondrial ion channels will enable us to find novel therapeutic targets for many diseases that are associated with cellular redox signaling and mitochondrial ion channels/transporters. Antioxid. Redox Signal. 21, 987–1006. PMID:24180309

  7. Membrane plasmalogen composition and cellular cholesterol regulation: a structure activity study

    PubMed Central

    2010-01-01

    Background Disrupted cholesterol regulation leading to increased circulating and membrane cholesterol levels is implicated in many age-related chronic diseases such as cardiovascular disease (CVD), Alzheimer's disease (AD), and cancer. In vitro and ex vivo cellular plasmalogen deficiency models have been shown to exhibit impaired intra- and extra-cellular processing of cholesterol. Furthermore, depleted brain plasmalogens have been implicated in AD and serum plasmalogen deficiencies have been linked to AD, CVD, and cancer. Results Using plasmalogen deficient (NRel-4) and plasmalogen sufficient (HEK293) cells we investigated the effect of species-dependent plasmalogen restoration/augmentation on membrane cholesterol processing. The results of these studies indicate that the esterification of cholesterol is dependent upon the amount of polyunsaturated fatty acid (PUFA)-containing ethanolamine plasmalogen (PlsEtn) present in the membrane. We further elucidate that the concentration-dependent increase in esterified cholesterol observed with PUFA-PlsEtn was due to a concentration-dependent increase in sterol-O-acyltransferase-1 (SOAT1) levels, an observation not reproduced by 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibition. Conclusion The present study describes a novel mechanism of cholesterol regulation that is consistent with clinical and epidemiological studies of cholesterol, aging and disease. Specifically, the present study describes how selective membrane PUFA-PlsEtn enhancement can be achieved using 1-alkyl-2-PUFA glycerols and through this action reduce levels of total and free cholesterol in cells. PMID:20546600

  8. 76 FR 22878 - Defense Transportation Regulation, Part IV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-25

    ... payment of Nontemporary Storage (NTS) invoices in the Defense Transportation Regulation (DTR) Part IV (DTR... transaction and payment system for all NTS Transportation Service Providers (TSP). Implementation of electronic payments for NTS at all Military Services and Coast Guard installations is the goal of the...

  9. 76 FR 66281 - Defense Transportation Regulation, Part IV

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... Federal Register Notice (FRN), Docket ID: DOD-2010- OS-0034, published April 1, 2010 (75 FR 16445-16446) and subsequently revised April 5, 2011 (76 FR 18737). We have taken industry recommendations into... of the Secretary Defense Transportation Regulation, Part IV AGENCY: United States...

  10. Cellular context–mediated Akt dynamics regulates MAP kinase signaling thresholds during angiogenesis

    PubMed Central

    Hellesøy, Monica; Lorens, James B.

    2015-01-01

    The formation of new blood vessels by sprouting angiogenesis is tightly regulated by contextual cues that affect angiogeneic growth factor signaling. Both constitutive activation and loss of Akt kinase activity in endothelial cells impair angiogenesis, suggesting that Akt dynamics mediates contextual microenvironmental regulation. We explored the temporal regulation of Akt in endothelial cells during formation of capillary-like networks induced by cell–cell contact with vascular smooth muscle cells (vSMCs) and vSMC-associated VEGF. Expression of constitutively active Akt1 strongly inhibited network formation, whereas hemiphosphorylated Akt1 epi-alleles with reduced kinase activity had an intermediate inhibitory effect. Conversely, inhibition of Akt signaling did not affect endothelial cell migration or morphogenesis in vSMC cocultures that generate capillary-like structures. We found that endothelial Akt activity is transiently blocked by proteasomal degradation in the presence of SMCs during the initial phase of capillary-like structure formation. Suppressed Akt activity corresponded to the increased endothelial MAP kinase signaling that was required for angiogenic endothelial morphogenesis. These results reveal a regulatory principle by which cellular context regulates Akt protein dynamics, which determines MAP kinase signaling thresholds necessary drive a morphogenetic program during angiogenesis. PMID:26023089

  11. NFAT5 in cellular adaptation to hypertonic stress - regulations and functional significance.

    PubMed

    Cheung, Chris Yk; Ko, Ben Cb

    2013-01-01

    The Nuclear Factor of Activated T Cells-5 (NFAT5), also known as OREBP or TonEBP, is a member of the nuclear factors of the activated T cells family of transcription factors. It is also the only known tonicity-regulated transcription factor in mammals. NFAT5 was initially known for its role in the hypertonic kidney inner medulla for orchestrating a genetic program to restore the cellular homeostasis. Emerging evidence, however, suggests that NFAT5 might play a more diverse functional role, including a pivotal role in blood pressure regulation and the development of autoimmune diseases. Despite the growing significance of NFAT5 in physiology and diseases, our understanding of how its activity is regulated remains very limited. Furthermore, how changes in tonicities are converted into functional outputs via NFAT5 remains elusive. Therefore, this review aims to summarize our current knowledge on the functional roles of NFAT5 in osmotic stress adaptation and the signaling pathways that regulate its activity. PMID:23618372

  12. Snai2 and Snai3 transcriptionally regulate cellular fitness and functionality of T cell lineages through distinct gene programs.

    PubMed

    Pioli, Peter D; Whiteside, Sarah K; Weis, Janis J; Weis, John H

    2016-05-01

    T lymphocytes are essential contributors to the adaptive immune system and consist of multiple lineages that serve various effector and regulatory roles. As such, precise control of gene expression is essential to the proper development and function of these cells. Previously, we identified Snai2 and Snai3 as being essential regulators of immune tolerance partly due to the impaired function of CD4(+) regulatory T cells in Snai2/3 conditional double knockout mice. Here we extend those previous findings using a bone marrow transplantation model to provide an environmentally unbiased view of the molecular changes imparted onto various T lymphocyte populations once Snai2 and Snai3 are deleted. The data presented here demonstrate that Snai2 and Snai3 transcriptionally regulate the cellular fitness and functionality of not only CD4(+) regulatory T cells but effector CD8(α+) and CD4(+) conventional T cells as well. This is achieved through the modulation of gene sets unique to each cell type and includes transcriptional targets relevant to the survival and function of each T cell lineage. As such, Snai2 and Snai3 are essential regulators of T cell immunobiology. PMID:26831822

  13. SIRT1-mediated deacetylation of CRABPII regulates cellular retinoic acid signaling and modulates embryonic stem cell differentiation

    PubMed Central

    Tang, Shuang; Huang, Gang; Fan, Wei; Chen, Yue; Ward, James M.; Xu, Xiaojiang; Xu, Qing; Kang, Ashley; McBurney, Michael W.; Fargo, David C.; Hu, Guang; Baumgart-Vogt, Eveline; Zhao, Yingming; Li, Xiaoling

    2014-01-01

    Summary Retinoid homeostasis is critical for normal embryonic development. Both the deficiency and excess of these compounds are associated with congenital malformations. Here we demonstrate that SIRT1, the most conserved mammalian NAD+-dependent protein deacetylase, contributes to homeostatic retinoic acid (RA) signaling and modulates mouse embryonic stem cell (mESC) differentiation in part through deacetylation of cellular retinoic acid binding protein II (CRABPII). We show that RA-mediated acetylation of CRABPII at K102 is essential for its nuclear accumulation and subsequent activation of RA signaling. SIRT1 interacts with and deacetylates CRABPII, regulating its subcellular localization. Consequently, SIRT1 deficiency induces hyper-acetylation and nuclear accumulation of CRABPII, enhancing RA signaling and accelerating mESC differentiation in response to RA. Consistently, SIRT1 deficiency is associated with elevated RA signaling and development defects in mice. Our findings reveal a novel molecular mechanism that regulates RA signaling, and highlight the importance of SIRT1 in regulation of ESC pluripotency and embryogenesis. PMID:25155613

  14. PTPN13 regulates cellular signalling and β-catenin function during megakaryocytic differentiation.

    PubMed

    Sardina, José L; López-Ruano, Guillermo; Prieto-Bermejo, Rodrigo; Sánchez-Sánchez, Beatriz; Pérez-Fernández, Alejandro; Sánchez-Abarca, Luis Ignacio; Pérez-Simón, José Antonio; Quintales, Luis; Sánchez-Yagüe, Jesús; Llanillo, Marcial; Antequera, Francisco; Hernández-Hernández, Angel

    2014-12-01

    PTPN13 is a high-molecular weight intracellular phosphatase with several isoforms that exhibits a highly modular structure. Although in recent years different roles have been described for PTPN13, we are still far from understanding its function in cell biology. Here we show that PTPN13 expression is activated during megakaryocytic differentiation at the protein and mRNA level. Our results show that the upregulation of PTPN13 inhibits megakaryocytic differentiation, while PTPN13 silencing triggers differentiation. The ability of PTPN13 to alter megakaryocytic differentiation can be explained by its capacity to regulate ERK and STAT signalling. Interestingly, the silencing of β-catenin produced the same effect as PTPN13 downregulation. We demonstrate that both proteins coimmunoprecipitate and colocalise. Moreover, we provide evidence showing that PTPN13 can regulate β-catenin phosphorylation, stability and transcriptional activity. Therefore, the ability of PTPN13 to control megakaryocytic differentiation must be intimately linked to the regulation of β-catenin function. Moreover, our results show for the first time that PTPN13 is stabilised upon Wnt signalling, which makes PTPN13 an important player in canonical Wnt signalling. Our results show that PTPN13 behaves as an important regulator of megakaryocytic differentiation in cell lines and also in murine haematopoietic progenitors. This importance can be explained by the ability of PTPN13 to regulate cellular signalling, and especially through the regulation of β-catenin stability and function. Our results hold true for different megakaryocytic cell lines and also for haematopoietic progenitors, suggesting that these two proteins may play a relevant role during in vivo megakaryopoiesis. PMID:25193362

  15. Cellular IAP proteins and LUBAC differentially regulate necrosome-associated RIP1 ubiquitination.

    PubMed

    de Almagro, M C; Goncharov, T; Newton, K; Vucic, D

    2015-01-01

    Necroptosis is a caspase-independent regulated type of cell death that relies on receptor-interacting protein kinases RIP1 (receptor-interacting protein kinases 1) and RIP3. Tumor necrosis factor-α (TNFα)-stimulated assembly of the TNFR1 (TNF receptor 1)-associated signaling complex leads to the recruitment of RIP1, whose ubiquitination is mediated by the cellular inhibitors of apoptosis (c-IAPs). Translocation of RIP1 to the cytoplasm and association of RIP1 with the necrosome is believed to correlate with deubiquitination of RIP1. However, we found that RIP1 is ubiquitinated with K63 and linear polyubiquitin chains during TNFα, IAP antagonist BV6 and caspase inhibitor zVAD-fmk-induced necroptotic signaling. Furthermore, ubiquitinated RIP1 is associated with the necrosome, and RIP1 ubiquitination in the necrosome coincides with RIP3 phosphorylation. Both cellular IAPs and LUBAC (linear ubiquitin chain assembly complex) modulate RIP1 ubiquitination in IAP antagonist-treated necrotic cells, but they use different mechanisms. c-IAP1 regulates RIP1 recruitment to the necrosome without directly affecting RIP1 ubiquitination, whereas HOIP and HOIL1 mediate linear ubiquitination of RIP1 in the necrosome, but are not essential for necrosome formation. Knockdown of the E3 ligase c-IAP1 decreased RIP1 ubiquitination, necrosome assembly and necroptosis induced by TNFα, BV6 and zVAD-fmk. c-IAP1 deficiency likely decreases necroptotic cell death through the activation of the noncanonical NF-κB pathway and consequent c-IAP2 upregulation. The ability to upregulate c-IAP2 could determine whether c-IAP1 absence will have a positive or negative impact on TNFα-induced necroptotic cell death and necrosome formation. Collectively, these results reveal unexpected complexity of the roles of IAP proteins, IAP antagonists and LUBAC in the regulation of necrosome assembly. PMID:26111062

  16. Previously uncharacterized isoforms of divalent metal transporter (DMT)-1: implications for regulation and cellular function.

    PubMed

    Hubert, Nadia; Hentze, Matthias W

    2002-09-17

    Divalent metal transporter 1 (DMT1) mediates apical iron uptake into duodenal enterocytes and also transfers iron from the endosome into the cytosol after cellular uptake via the transferrin receptor. Hence, mutations in DMT1 cause systemic iron deficiency and anemia. DMT1 mRNA levels are increased in the duodenum of iron-deficient animals. This regulation has been observed for DMT1 mRNA harboring an iron-responsive element (IRE) in its 3' UTR, but not for a processing variant lacking a 3'UTR IRE, suggesting that the IRE regulates the expression of DMT1 mRNA in response to iron levels. Here, we show that iron regulation of DMT1 involves the expression of a previously unrecognized upstream 5' exon (exon 1A) of the human and murine DMT1 gene. The expression of this previously uncharacterized 5' exon is tissue-specific and particularly prevalent in the duodenum and kidney. It adds an in-frame AUG translation initiation codon extending the DMT1 ORF by a conserved sequence of 29-31 amino acids. In combination with the IRE- and non-IRE variants in the 3'UTR, our results reveal the existence of four DMT1 mRNA isoforms predicting the synthesis of four different DMT1 proteins. We show that two regulatory regions, the 5' promoter/exon 1A region and the IRE-containing terminal exon participate in iron regulation of DMT1 expression, which operate in a tissue-specific way. These results uncover an unexpected complexity of DMT1 expression and regulation, with implications for understanding the physiology, cell biology, and pathophysiology of mammalian iron metabolism. PMID:12209011

  17. Cellular stress induces Bax-regulated nuclear bubble budding and rupture followed by nuclear protein release.

    PubMed

    Lindenboim, Liora; Sasson, Tiki; Worman, Howard J; Borner, Christoph; Stein, Reuven

    2014-01-01

    Cellular stress triggers many pathways including nuclear protein redistribution. We previously discovered that this process is regulated by Bax but the underlying mechanism has not yet been studied. Here we define this mechanism by showing that apoptotic stimuli cause Bax-regulated disturbances in lamin A/C and nuclear envelope (NE)-associated proteins which results in the generation and subsequent rupture of nuclear protein-containing bubbles. The bubbles do not contain DNA and are encapsulated by impaired nuclear pore-depleted NE. Stress-induced generation and rupture of nuclear bubbles ultimately leads to the discharge of nuclear proteins into the cytoplasm. This process precedes morphological changes of apoptosis and occurs independently of caspases. Rescue experiments revealed that this Bax effect is non-canonical, i.e. it requires the BH3 domain and α-helices 5 and 6 but it is not inhibited by Bcl(-)xL. Targeting Bax to the NE by the Klarsicht/ANC-1/Syne-1 homology (KASH) domain effectively triggers the generation and rupture of nuclear bubbles. Overall, our findings provide evidence for a novel stress-response, which is regulated by a non-canonical action of Bax on the NE. PMID:25482068

  18. A High-Content Imaging Screen for Cellular Regulators of β-Catenin Protein Abundance.

    PubMed

    Zeng, Xin; Montoute, Monica; Bee, Tiger W; Lin, Hong; Kallal, Lorena A; Liu, Yan; Agarwal, Pankaj; Wang, Dayuan; Lu, Quinn; Morrow, Dwight; Pope, Andrew J; Wu, Zining

    2016-03-01

    Abnormal accumulation of β-catenin protein, a key transcriptional activator required for Wnt signaling, is the hallmark of many tumor types, including colon cancer. In normal cells, β-catenin protein level is tightly controlled by a multiprotein complex through the proteosome pathway. Mutations in the components of the β-catenin degradation complex, such as adenomatous polyposis coli (APC) and Axin, lead to β-catenin stabilization and the constitutive activation of target genes. Since the signal transduction of Wnt/β-catenin is mainly mediated by protein-protein interactions, this pathway has been particularly refractory to conventional target-based small-molecule screening. Here we designed a cellular high-content imaging assay to detect β-catenin protein through immunofluorescent staining in the SW480 colon cancer cell line, which has elevated β-catenin endogenously. We demonstrate that the assay is robust and specific to screen a focused biologically diverse chemical library set against known targets that play diverse cellular functions. We identified a number of hits that reduce β-catenin levels without causing cell death. These hits may serve as tools to understand the dynamics of β-catenin degradation. This study demonstrates that detecting cell-based β-catenin protein stability is a viable approach to identifying novel mechanisms of β-catenin regulation as well as small molecules of therapeutic potential. PMID:26656867

  19. Nitric Oxide and ERK mediates regulation of cellular processes by Ecdysterone.

    PubMed

    Omanakuttan, Athira; Bose, Chinchu; Pandurangan, Nanjan; Kumar, Geetha B; Banerji, Asoke; Nair, Bipin G

    2016-08-15

    The complex process of wound healing is a major problem associated with diabetes, venous or arterial disease, old age and infection. A wide range of pharmacological effects including anabolic, anti-diabetic and hepato-protective activities have been attributed to Ecdysterone. In earlier studies, Ecdysterone has been shown to modulate eNOS and iNOS expression in diabetic animals and activate osteogenic differentiation through the Extracellular-signal-Regulated Kinase (ERK) pathway in periodontal ligament stem cells. However, in the wound healing process, Ecdysterone has only been shown to enhance granulation tissue formation in rabbits. There have been no studies to date, which elucidate the molecular mechanism underlying the complex cellular process involved in wound healing. The present study, demonstrates a novel interaction between the phytosteroid Ecdysterone and Nitric Oxide Synthase (NOS), in an Epidermal Growth Factor Receptor (EGFR)-dependent manner, thereby promoting cell proliferation, cell spreading and cell migration. These observations were further supported by the 4-amino-5-methylamino- 2' ,7' -difluorofluorescein diacetate (DAF FM) fluorescence assay which indicated that Ecdysterone activates NOS resulting in increased Nitric Oxide (NO) production. Additionally, studies with inhibitors of both the EGFR and ERK, demonstrated that Ecdysterone activates NOS through modulation of EGFR and ERK. These results clearly demonstrate, for the first time, that Ecdysterone enhances Nitric Oxide production and modulates complex cellular processes by activating ERK1/2 through the EGF pathway. PMID:27448766

  20. PAT proteins, an ancient family of lipid droplet proteins that regulate cellular lipid stores.

    PubMed

    Bickel, Perry E; Tansey, John T; Welte, Michael A

    2009-06-01

    The PAT family of lipid droplet proteins includes 5 members in mammals: perilipin, adipose differentiation-related protein (ADRP), tail-interacting protein of 47 kDa (TIP47), S3-12, and OXPAT. Members of this family are also present in evolutionarily distant organisms, including insects, slime molds and fungi. All PAT proteins share sequence similarity and the ability to bind intracellular lipid droplets, either constitutively or in response to metabolic stimuli, such as increased lipid flux into or out of lipid droplets. Positioned at the lipid droplet surface, PAT proteins manage access of other proteins (lipases) to the lipid esters within the lipid droplet core and can interact with cellular machinery important for lipid droplet biogenesis. Genetic variations in the gene for the best-characterized of the mammalian PAT proteins, perilipin, have been associated with metabolic phenotypes, including type 2 diabetes mellitus and obesity. In this review, we discuss how the PAT proteins regulate cellular lipid metabolism both in mammals and in model organisms. PMID:19375517

  1. Role of diacylglycerol kinase in cellular regulatory processes: a new regulator for cardiomyocyte hypertrophy.

    PubMed

    Takeishi, Yasuchika; Goto, Kaoru; Kubota, Isao

    2007-09-01

    Diacylglycerol (DAG) kinase (DGK) phosphorylates and converts DAG to phosphatidic acid. DGK regulates cellular DAG levels and attenuates DAG signaling. The 10 mammalian DGK isoforms have been identified to date. In cardiac myocytes, DGKalpha, epsilon, and zeta are expressed, and DGKzeta is the predominant isoform. DGKzeta inhibits protein kinase C (PKC) activation and subsequent hypertrophic programs in response to endothelin-1 (ET-1) in neonatal rat cardiomyocytes. DGKzeta blocks cardiac hypertrophy induced by G protein-coupled receptor agonists and pressure overload in vivo. DGKzeta attenuates ventricular remodeling and improves survival after myocardial infarction. These data provide a novel insight for subcellular mechanisms of cardiac hypertrophy and heart failure, and DGKzeta may be a new therapeutic target to prevent cardiac hypertrophy and progression to heart failure. PMID:17659347

  2. BMP2 Regulation of CXCL12 Cellular, Temporal, and Spatial Expression is Essential During Fracture Repair.

    PubMed

    Myers, Timothy J; Longobardi, Lara; Willcockson, Helen; Temple, Joseph D; Tagliafierro, Lidia; Ye, Ping; Li, Tieshi; Esposito, Alessandra; Moats-Staats, Billie M; Spagnoli, Anna

    2015-11-01

    -reaching implications for understanding mechanisms regulating the selective recruitment of distinct cells into the repairing niches and the development of novel pharmacological (by targeting BMP2/CXCL12) and cellular (MSCs, endosteal cells) interventions to promote fracture healing. PMID:25967044

  3. BMP2 Regulation of CXCL12 Cellular, Temporal, and Spatial Expression is Essential During Fracture Repair

    PubMed Central

    Myers, Timothy J; Longobardi, Lara; Willcockson, Helen; Temple, Joseph D; Tagliafierro, Lidia; Ye, Ping; Li, Tieshi; Esposito, Alessandra; Moats-Staats, Billie M; Spagnoli, Anna

    2016-01-01

    -reaching implications for understanding mechanisms regulating the selective recruitment of distinct cells into the repairing niches and the development of novel pharmacological (by targeting BMP2/CXCL12) and cellular (MSCs, endosteal cells) interventions to promote fracture healing. PMID:25967044

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

    SciTech Connect

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

    2014-04-04

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

  5. Cellular Expression of Smarca4 (Brg1)-regulated Genes in Zebrafish Retinas

    PubMed Central

    2011-01-01

    Background In a recent genomic study, Leung et al. used a factorial microarray analysis to identify Smarca4 (Brg1)-regulated genes in micro-dissected zebrafish retinas. Two hundred and fifty nine genes were grouped in three-way ANOVA models which carried the most specific retinal change. To validate the microarray results and to elucidate cellular expression patterns of the significant genes for further characterization, 32 known genes were randomly selected from this group. In situ hybridization of these genes was performed on the same types of samples (wild-type (WT) and smarca4a50/a50 (yng) mutant) at the same stages (36 and 52 hours post-fertilization (hpf)) as in the microarray study. Results Thirty out of 32 riboprobes showed a positive in situ staining signal. Twenty seven out of these 30 genes were originally further classified as Smarca4-regulated retinal genes, while the remaining three as retinal-specific expression independent of Smarca4 regulation. It was found that 90.32% of the significant microarray comparisons that were used to identify Smarca4-regulated retinal genes had a corresponding qualitative expression change in the in situ hybridization comparisons. This is highly concordant with the theoretical true discovery rate of 95%. Hierarchical clustering was used to investigate the similarity of the cellular expression patterns of 25 out of the 27 Smarca4-regulated retinal genes that had a sufficiently high expression signal for an unambiguous identification of retinal expression domains. Three broad groups of expression pattern were identified; including 1) photoreceptor layer/outer nuclear layer specific expression at 52 hpf, 2) ganglion cell layer (GCL) and/or inner nuclear layer (INL) specific expression at both 36 & 52 hpf, and 3) GCL and/or INL specific expression at 52 hpf only. Some of these genes have recently been demonstrated to play key roles in retinal cell-type specification, differentiation and lamination. For the remaining three

  6. Protease activated receptor-1 regulates macrophage-mediated cellular senescence: a risk for idiopathic pulmonary fibrosis

    PubMed Central

    Lin, Cong; Rezaee, Farhad; Waasdorp, Maaike; Shi, Kun; van der Poll, Tom

    2015-01-01

    Idiopathic pulmonary fibrosis (IPF) is a destructive disease in part resulting from premature or mature cellular aging. Protease-activated receptor-1 (PAR-1) recently emerged as a critical component in the context of fibrotic lung diseases. Therefore, we aimed to study the role of macrophages in PAR-1-mediated idiopathic pulmonary fibrosis. The number of macrophages were significantly reduced in lungs of PAR-1 antagonist (P1pal-12) treated animals upon bleomycin instillation. In line with these data, PAR-1 stimulation increased monocyte/macrophage recruitment in response to epithelium injury in in vitro trans-well assays. Moreover, macrophages induced fibroblasts migration, differentiation and secretion of collagen, which were inhibited in the presence of TGF-β receptor inhibitors. Interestingly, these profibrotic effects were partially inhibited by treatment with the PAR-1 inhibitor P1pal-12. Using shRNA mediated PAR-1 knock down in fibroblasts, we demonstrate that fibroblast PAR-1 contributes to TGF-β activation and production. Finally, we show that the macrophage-dependent induction of PAR-1 driven TGF-β activation was mediated by FXa. Our data identify novel mechanisms by which PAR-1 stimulation on different cell types can contribute to IPF and identify macrophages as key players in PAR-1 dependent development of this devastating disease. IPF may result from cellular senescence mediated by macrophages in the lung. PMID:26474459

  7. Physical principles of genomic regulation through cellular nanoscale structure and implications for initiation of carcinogenesis

    NASA Astrophysics Data System (ADS)

    Backman, Vadim

    2011-03-01

    Although compelling evidence suggests that cellular nanoarchitecture and nanoscale environment where molecular interactions take place would be expected to significantly affect macromolecular processes, biological ramifications of cellular nanoscale organization have been largely unexplored. This understanding has been hampered in part by the diffraction limited resolution of optical microscopy. The talk will discuss a novel optical microscopy technique, partial wave spectroscopic (PWS) microscopy, that is capable of quantifying statistical properties of cell structure at the nanoscale. Animal and human studies demonstrated that an alteration in the statistical properties of the nanoscale mass density distribution in the cell nucleus (e.g. nuclear nanoarchitecture) is one of the earliest and ubiquitous events in carcinogenesis and precedes any other known morphological changes at larger length scales (e.g. microarchitecture). The talk will also discuss the physical principles of how the alteration in nuclear nanoarchitecture may modulate genomic processes and, in particular, gene transcription. Work done in collaboration with Hariharan Subramanian, Prabhakar Pradhan, Dhwanil Damania, Lusik Cherkezyan, Yolanda Stypula, Jun Soo Kim, Igal Szleifer, Northwestern University, Evanston, IL, Hemant K. Roy, Northshore University HealthSystems, Evanston, IL

  8. Cellular levels of feedback regulator of adenylate cyclase and the effect of epinephrine and insulin.

    PubMed Central

    Ho, R j; Russell, T R; Asakawa, T; Sutherland, E W

    1975-01-01

    We have obtained direct evidence that shows the cellular formation and subsequent release of a potent inhibitor (feedback regulator) of adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] by adipocytes, upon stimulation with epinephrine. The appearance of such a feedback regulator in adipocytes preceded its release into the medium. During a 30 min incubation, intracellular regulator levels rose rapidly and reached 39-61 units/g of adipocyte at 10 min. Release of inhibitor into the medium increased slowly and was 11-16 units/g of adipocyte at 10 min. Upon continued incubation, the cells at 30 min contained 30-41 units/g of ingibitor, slightly less than the content at 30 min; meanwhile, the medium content rose more than 3-fold. The inhibitor from both locations appeared to have the same characteristics, judging from the purification procedures and the biological activities on hormone-stimulated adenylate cyclase. Adenylate cyclase was inhibited by the feedback regulator in vitro when either epinephrine, corticotropin (ACTH), or glucagon was used as activator. The site of action of this inhibitor is therefore most likely beyond the specific hormone receptors. A new in vitro action of insulin has been found. Insulin, 50-500 microunits/ml, inhibited the formation and release of this factor from isolated rat or hamster adipocytes by 29-81% after these cells were stimulated by hormones that raise intracellular adenosine 3':5'-cyclic monophosphate. This factor enhaced the effect of insulin in lowering the adenosine 3':5'-cyclic monophosphate levels in fresh rat adipocytes. A reduced formation of such a factor may modify the metabolic events in adipocytes, and some as yet unexplained effects of insulin could therefore be linked to the metabolic effects of this factor. PMID:174073

  9. EGF-mediated regulation of IGFBP-3 determines esophageal epithelial cellular response to IGF-I

    PubMed Central

    Takaoka, Munenori; Smith, Caitlin E.; Mashiba, Michael K.; Okawa, Takaomi; Andl, Claudia D.; El-Deiry, Wafik S.; Nakagawa, Hiroshi

    2010-01-01

    IGF and EGF regulate various physiological and pathological processes. IGF binding protein (IGFBP)-3 regulates cell proliferation in IGF-dependent and -independent fashions. Recently, we identified IGFBP-3 as a novel EGF receptor (EGFR) downstream target molecule in primary and immortalized human esophageal epithelial cells, suggesting an interplay between the EGF and IGF signaling pathways. However, the regulatory mechanisms for IGFBP-3 expression and its functional role in esophageal cell proliferation remain to be elucidated. Herein, we report that IGFBP-3 mRNA and protein were induced upon growth factor deprivation in primary and immortalized human esophageal cells through mechanisms requiring p53-independent de novo mRNA transcription and protein synthesis. This occurred in the face of the activated phosphatidylinositol 3-OH-kinase (PI3K)/mammalian target of rapamycin (mTOR) pathway. Secreted IGFBP-3 neutralized IGFs and prevented IGF-I receptor (IGF-IR) activation. In contrast, EGF suppressed IGFBP-3 mRNA and protein expression through activation of MAPK in an EGFR-tyrosine kinase-dependent manner to restore the cellular response to IGF-I. When stably overexpressed, wild-type IGFBP-3 but not I56G/L80G/L81G (GGG) mutant IGFBP-3, which has a reduced affinity to IGFs, prevented IGF-I from activating IGF-IR and Akt as well as stimulating cell proliferation. However, unlike other cell types where IGFBP-3 exerts antiproliferative effects, neither wild-type nor GGG mutant IGFBP-3 alone affected cell proliferation or EGFR activity. These results indicate that IGF signaling is subject to negative regulation through IGFBP-3 and positive regulation by EGF, the latter of which suppresses IGFBP-3. This provides a platform for understanding the novel cross talk between EGF- and IGF-mediated pathways. PMID:16210470

  10. ECM signaling regulates collective cellular dynamics to control pancreas branching morphogenesis

    PubMed Central

    Shih, Hung Ping; Panlasigui, Devin; Cirulli, Vincenzo; Sander, Maike

    2015-01-01

    Summary During pancreas development, epithelial buds undergo branching morphogenesis to form an exocrine and endocrine gland. Proper morphogenesis is necessary for correct lineage allocation of pancreatic progenitors; however, the cellular events underlying pancreas morphogenesis are unknown. Here, we employed time-lapse microscopy and fluorescent labeling of cells to analyze cell behaviors associated with pancreas morphogenesis. We observed that outer bud cells adjacent to the basement membrane are pleomorphic and rearrange frequently; as well, they largely remain in the outer cell compartment even after mitosis. These cell behaviors and pancreas branching depend on cell contacts with the basement membrane, which induce actomyosin cytoskeleton remodeling via integrin-mediated activation of FAK/Src signaling. We show that integrin signaling reduces E-cadherin-mediated cell-cell adhesion in outer cells, and provide genetic evidence that this regulation is necessary for initiation of branching. Our study suggests that regulation of cell motility and adhesion by local niche cues initiates pancreas branching morphogenesis. PMID:26748698

  11. HMGB1 and HMGB2 proteins up-regulate cellular expression of human topoisomerase IIα

    PubMed Central

    Štros, Michal; Polanská, Eva; Štruncová, Soňa; Pospíšilová, Šárka

    2009-01-01

    Topoisomerase IIα (topo IIα) is a nuclear enzyme involved in several critical processes, including chromosome replication, segregation and recombination. Previously we have shown that chromosomal protein HMGB1 interacts with topo IIα, and stimulates its catalytic activity. Here we show the effect of HMGB1 on the activity of the human topo IIα gene promoter in different cell lines. We demonstrate that HMGB1, but not a mutant of HMGB1 incapable of DNA bending, up-regulates the activity of the topo IIα promoter in human cells that lack functional retinoblastoma protein pRb. Transient over-expression of pRb in pRb-negative Saos-2 cells inhibits the ability of HMGB1 to activate the topo IIα promoter. The involvement of HMGB1 and its close relative, HMGB2, in modulation of activity of the topo IIα gene is further supported by knock-down of HMGB1/2, as evidenced by significantly decreased levels of topo IIα mRNA and protein. Our experiments suggest a mechanism of up-regulation of cellular expression of topo IIα by HMGB1/2 in pRb-negative cells by modulation of binding of transcription factor NF-Y to the topo IIα promoter, and the results are discussed in the framework of previously observed pRb-inactivation, and increased levels of HMGB1/2 and topo IIα in tumors. PMID:19223331

  12. TRPM6 kinase activity regulates TRPM7 trafficking and inhibits cellular growth under hypomagnesic conditions

    PubMed Central

    Brandao, Katherine; Deason-Towne, Francina; Zhao, Xiaoyun; Perraud, Anne-Laure; Schmitz, Carsten

    2014-01-01

    The channel kinases TRPM6 and TRPM7 are both members of the melastatin related transient receptor potential (TRPM) subfamily of ion channels and the only known fusions of an ion channel pore with a kinase domain. TRPM6 and TRPM7 form functional, tetrameric channel complexes at the plasma membrane by heteromerization. TRPM6 was previously shown to cross-phosphorylate TRPM7 on threonine residues, but not vice versa. Genetic studies demonstrated that TRPM6 and TRPM7 fulfill non-redundant functions, and that each channel contributes uniquely to the regulation of Mg2+ homeostasis. Although there are indications that TRPM6 and TRPM7 can influence each other’s cellular distribution and activity, little is known about the functional relationship between these two channel-kinases. In the present study, we examined how TRPM6 kinase activity influences TRPM7 serine phosphorylation, intracellular trafficking, and cell surface expression of TRPM7, as well as Mg2+-dependent cellular growth. We found TRPM7 serine phosphorylation via the TRPM6 kinase, but no TRPM6 serine phosphorylation via the TRPM7 kinase. Intracellular trafficking of TRPM7 was altered in HEK-293 epithelial kidney cells and DT40 B cells in the presence of TRPM6 with intact kinase activity, independently of the availability of extracellular Mg2+, but TRPM6/7 surface labeling experiments indicate comparable levels of the TRPM6/7 channels at the plasma membrane. Furthermore, using a complementation approach in TRPM7-deficient DT40 B-cells, we demonstrated that wildtype TRPM6 inhibited cell growth under hypomagnesic cell culture conditions in cells co-expressing TRPM6 and TRPM7, however co-expression of a TRPM6 kinase dead mutant had no effect – a similar phenotype was also observed in TRPM6/7 co-expressing HEK-293 cells. Our results provide first clues about how heteromer formation between TRPM6 and TRPM7 influences the biological activity of these ion channels. We show that TRPM6 regulates TRPM7 intracellular

  13. 75 FR 59102 - Defense Federal Acquisition Regulation Supplement; Part 204, Administrative Matters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-27

    ...; Part 204, Administrative Matters AGENCY: Defense Acquisition Regulations System, Department of Defense.... 0 Therefore 48 CFR part 204 is amended as follows: PART 204--ADMINISTRATIVE MATTERS 0 1....

  14. Nrf2 Protein Up-regulates Antiapoptotic Protein Bcl-2 and Prevents Cellular Apoptosis*

    PubMed Central

    Niture, Suryakant K.; Jaiswal, Anil K.

    2012-01-01

    Nuclear transcription factor Nrf2 regulates the expression and coordinated induction of a battery of genes encoding cytoprotective and drug transporter proteins in response to chemical and radiation stress. This leads to reduced apoptosis, enhanced cell survival, and increased drug resistance. In this study, we investigated the role of Nrf2 in up-regulation of antiapoptotic protein Bcl-2 and its contribution to stress-induced apoptosis and cell survival. Exposure of mouse hepatoma (Hepa-1) and human hepatoblastoma (HepG2) cells to antioxidant tert-butylhydroquinone led to induction of Bcl-2. Mutagenesis and transfection assays identified an antioxidant response element between nucleotides −3148 and −3140 on the reverse strand of the Bcl-2 gene promoter that was essential for activation of Bcl-2 gene expression. Band/supershift and ChIP assays demonstrated binding of Nrf2 to Bcl-2 antioxidant response element. Alterations in Nrf2 led to altered Bcl-2 induction and cellular apoptosis. Moreover, dysfunctional/mutant inhibitor of Nrf2 (INrf2) in human lung cancer cells failed to degrade Nrf2, resulting in an increased Bcl-2 level and decreased etoposide- and UV/γ radiation-mediated DNA fragmentation. In addition, siRNA-mediated down-regulation of Nrf2 also led to decreased apoptosis and increased cell survival. Furthermore, the specific knockdown of Bcl-2 in Nrf2-activated tumor cells led to increased etoposide-induced apoptosis and decreased cell survival and growth/proliferation. These data provide the first evidence of Nrf2 in control of Bcl-2 expression and apoptotic cell death with implications in antioxidant protection, survival of cancer cells, and drug resistance. PMID:22275372

  15. PI3K/AKT and ERK regulate retinoic acid-induced neuroblastoma cellular differentiation

    SciTech Connect

    Qiao, Jingbo; Paul, Pritha; Lee, Sora; Qiao, Lan; Josifi, Erlena; Tiao, Joshua R.; Chung, Dai H.

    2012-08-03

    Highlights: Black-Right-Pointing-Pointer Retinoic acid (RA) induces neuroblastoma cells differentiation, which is accompanied by G0/G1 cell cycle arrest. Black-Right-Pointing-Pointer RA resulted in neuroblastoma cell survival and inhibition of DNA fragmentation; this is regulated by PI3K pathway. Black-Right-Pointing-Pointer RA activates PI3K and ERK1/2 pathway; PI3K pathway mediates RA-induced neuroblastoma cell differentiation. Black-Right-Pointing-Pointer Upregulation of p21 is necessary for RA-induced neuroblastoma cell differentiation. -- Abstract: Neuroblastoma, the most common extra-cranial solid tumor in infants and children, is characterized by a high rate of spontaneous remissions in infancy. Retinoic acid (RA) has been known to induce neuroblastoma differentiation; however, the molecular mechanisms and signaling pathways that are responsible for RA-mediated neuroblastoma cell differentiation remain unclear. Here, we sought to determine the cell signaling processes involved in RA-induced cellular differentiation. Upon RA administration, human neuroblastoma cell lines, SK-N-SH and BE(2)-C, demonstrated neurite extensions, which is an indicator of neuronal cell differentiation. Moreover, cell cycle arrest occurred in G1/G0 phase. The protein levels of cyclin-dependent kinase inhibitors, p21 and p27{sup Kip}, which inhibit cell proliferation by blocking cell cycle progression at G1/S phase, increased after RA treatment. Interestingly, RA promoted cell survival during the differentiation process, hence suggesting a potential mechanism for neuroblastoma resistance to RA therapy. Importantly, we found that the PI3K/AKT pathway is required for RA-induced neuroblastoma cell differentiation. Our results elucidated the molecular mechanism of RA-induced neuroblastoma cellular differentiation, which may be important for developing novel therapeutic strategy against poorly differentiated neuroblastoma.

  16. Post-translational regulation of the 54K cellular tumor antigen in normal and transformed cells.

    PubMed Central

    Oren, M; Maltzman, W; Levine, A J

    1981-01-01

    The 54K cellular tumor antigen has been translated in vitro, using messenger ribonucleic acids from simian virus 40 (SV40)-transformed cells or 3T3 cells. The in vitro 54K product could be immunoprecipitated with SV40 tumor serum and had a peptide map that was similar, but not identical, to the in vivo product. The levels of this 54K protein in SV3T3 cells were significantly higher than those detected in 3T3 cells (D. I. H. Linzer, W. Maltzman, and A. J. Levine, Virology 98:308-318, 1979). In spite of this, the levels of translatable 54K messenger ribonucleic acid from 3T3 and SV3T3 cells were roughly equivalent or often greater in 3T3 cells. Pulse-chase experiments with the 54K protein from 3T3 or SV3T3 cells demonstrated that this protein, once synthesized, was rapidly degraded in 3T3 cells but was extremely stable in SV3T3 cells. Similarly, in an SV40 tsA-transformed cell line, temperature sensitive for the SV40 T-antigen, the 54K protein was rapidly turned over at the nonpermissive temperature and stable at the permissive temperature, whereas the levels of translatable 54K messenger ribonucleic acid at each temperature were roughly equal. These results demonstrate a post-translational regulation of the 54K cellular tumor antigen and suggest that this control is mediated by the SV40 large T-antigen. Images PMID:6100960

  17. Regulation of cellular behaviors of fibroblasts related to wound healing by sol-gel derived bioactive glass particles.

    PubMed

    Xie, Weihan; Chen, Xiaofeng; Miao, Guohou; Tang, Jieying; Fu, Xiaoling

    2016-10-01

    Sol-gel derived bioactive glass (BG) holds great potential in the application of skin repair. However, the specific regulation of BG on skin cells is still unclear and demands more investigation. Herein, we synthesized sol-gel derived BGs with different compositions (60S, 70S, 80S, and 90S) and found 90S BGs (90 mol % SiO2 , 6 mol % CaO, 4 mol % P2 O5 ) exhibited the best supportiveness for the proliferation of normal human foreskin fibroblasts. Thus, 90S BG particles were used as a model to systematically study the wound healing related cellular response of fibroblasts to BGs. Time-lapse imaging revealed a promoted fibroblast motility stimulated by 90S BG particles. Results on the expression of extracellular matrix (ECM) related genes illustrated that 90S BG particles modulated the synthesis capacity for critical ECM molecules including type I collagen, type III collagen, fibronectin, and tenascin-C. Moreover, the myofibroblastic differentiation of fibroblasts was greatly inhibited by 90S BG particles. Further analysis on the intracellular signaling pathways demonstrated that 90S BG particles down-regulated the collagen synthesis and fibroblast-to-myofibroblast differentiation via TGF-β1-Smad2 signaling, evidenced by the decreased expression levels of TGF-β receptor I and its downstream effector Smad2. Our study provided a further understanding of the specific regulation of 90S BG particles on fibroblasts, which may guide the future design of BG based wound dressing and benefit the clinical application of BG particles in skin repair. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2420-2429, 2016. PMID:27177533

  18. Involvement of the iron regulatory protein from Eisenia andrei earthworms in the regulation of cellular iron homeostasis.

    PubMed

    Procházková, Petra; Škanta, František; Roubalová, Radka; Šilerová, Marcela; Dvořák, Jiří; Bilej, Martin

    2014-01-01

    Iron homeostasis in cells is regulated by iron regulatory proteins (IRPs) that exist in different organisms. IRPs are cytosolic proteins that bind to iron-responsive elements (IREs) of the 5'- or 3'-untranslated regions (UTR) of mRNAs that encode many proteins involved in iron metabolism. In this study, we have cloned and described a new regulatory protein belonging to the family of IRPs from the earthworm Eisenia andrei (EaIRP). The earthworm IRE site in 5'-UTR of ferritin mRNA most likely folds into a secondary structure that differs from the conventional IRE structures of ferritin due to the absence of a typically unpaired cytosine that participates in protein binding. Prepared recombinant EaIRP and proteins from mammalian liver extracts are able to bind both mammalian and Eisenia IRE structures of ferritin mRNA, although the affinity of the rEaIRP/Eisenia IRE structure is rather low. This result suggests the possible contribution of a conventional IRE structure. When IRP is supplemented with a Fe-S cluster, it can function as a cytosolic aconitase. Cellular cytosolic and mitochondrial fractions, as well as recombinant EaIRP, exhibit aconitase activity that can be abolished by the action of oxygen radicals. The highest expression of EaIRP was detected in parts of the digestive tract. We can assume that earthworms may possess an IRE/IRP regulatory network as a potential mechanism for maintaining cellular iron homeostasis, although the aconitase function of EaIRP is most likely more relevant. PMID:25279857

  19. Involvement of the Iron Regulatory Protein from Eisenia andrei Earthworms in the Regulation of Cellular Iron Homeostasis

    PubMed Central

    Procházková, Petra; Škanta, František; Roubalová, Radka; Šilerová, Marcela; Dvořák, Jiří; Bilej, Martin

    2014-01-01

    Iron homeostasis in cells is regulated by iron regulatory proteins (IRPs) that exist in different organisms. IRPs are cytosolic proteins that bind to iron-responsive elements (IREs) of the 5′- or 3′-untranslated regions (UTR) of mRNAs that encode many proteins involved in iron metabolism. In this study, we have cloned and described a new regulatory protein belonging to the family of IRPs from the earthworm Eisenia andrei (EaIRP). The earthworm IRE site in 5′-UTR of ferritin mRNA most likely folds into a secondary structure that differs from the conventional IRE structures of ferritin due to the absence of a typically unpaired cytosine that participates in protein binding. Prepared recombinant EaIRP and proteins from mammalian liver extracts are able to bind both mammalian and Eisenia IRE structures of ferritin mRNA, although the affinity of the rEaIRP/Eisenia IRE structure is rather low. This result suggests the possible contribution of a conventional IRE structure. When IRP is supplemented with a Fe-S cluster, it can function as a cytosolic aconitase. Cellular cytosolic and mitochondrial fractions, as well as recombinant EaIRP, exhibit aconitase activity that can be abolished by the action of oxygen radicals. The highest expression of EaIRP was detected in parts of the digestive tract. We can assume that earthworms may possess an IRE/IRP regulatory network as a potential mechanism for maintaining cellular iron homeostasis, although the aconitase function of EaIRP is most likely more relevant. PMID:25279857

  20. Transferrin synthesis by small cell lung cancer cells acts as an autocrine regulator of cellular proliferation.

    PubMed Central

    Vostrejs, M; Moran, P L; Seligman, P A

    1988-01-01

    Since transferrin is required for cellular proliferation, we investigated transferrin synthesis by a small cell lung cancer line (NCI-H510) that survives in serum-free media without added transferrin. Immunoassays for human transferrin demonstrated that these cells contained immunoreactive human transferrin. Immunofluorescence studies showed that the protein is expressed on the surface of cells, presumably bound to transferrin receptor. Media conditioned by NCI-H510 cells support proliferation of human leukemic cells that would not survive in media lacking transferrin. [35S]Methionine incorporation documented transferrin synthesis by NCI-H510 cells as well as three other small cell lines. Transferrin synthesis by NCI-H510 cells increased more than 10-fold when cells entered active phases of the cell cycle, and this increase was seen before large increases in transferrin-receptor expression. Further experiments examining the effects of agents that affect iron metabolism show that the addition of transferrin-iron or hemin to the media is associated with a more rapid initial rate of proliferation and lower rates of transferrin synthesis than control cells. Gallium salts, which inhibit iron uptake, inhibited proliferation of these cells. If the cells recovered from this effect, transferrin synthesis remained greatly increased compared to control. We conclude that transferrin synthesis by these malignant cells is ultimately related to an iron requirement for cellular proliferation. It appears that this synthesized transferrin acts as part of an important autocrine mechanism permitting proliferation of these cells, and perhaps permitting tumor cell growth in vivo in areas not well vascularized. Images PMID:2839550

  1. A mitochondrial RNAi screen defines cellular bioenergetic determinants and identifies an adenylate kinase as a key regulator of ATP levels

    PubMed Central

    Lanning, Nathan J.; Looyenga, Brendan D.; Kauffman, Audra L.; Niemi, Natalie M.; Sudderth, Jessica; DeBerardinis, Ralph J.; MacKeigan, Jeffrey P.

    2014-01-01

    Summary Altered cellular bioenergetics and mitochondrial function are major features of several diseases including cancer, diabetes, and neurodegenerative disorders. Given this important link to human health, we sought to define proteins within mitochondria that are critical for maintaining homeostatic ATP levels. We screened an RNAi library targeting >1,000 nuclear-encoded genes whose protein products localize to the mitochondria in multiple metabolic conditions to examine their effect on cellular ATP levels. We identified a mechanism by which electron transport chain perturbation under glycolytic conditions increased ATP production through enhanced glycolytic flux; thereby highlighting the cellular potential for metabolic plasticity. Additionally, we identified a mitochondrial adenylate kinase (AK4) that regulates cellular ATP levels, AMPK signaling, and whose expression significantly correlates with glioma patient survival. As a result, this study maps the bioenergetic landscape of >1,000 mitochondrial proteins in the context of varied metabolic substrates and begins to link key metabolic genes with clinical outcome. PMID:24767988

  2. Differential Regulation of Cellular Senescence and Differentiation by Prolyl Isomerase Pin1 in Cardiac Progenitor Cells*

    PubMed Central

    Toko, Haruhiro; Hariharan, Nirmala; Konstandin, Mathias H.; Ormachea, Lucia; McGregor, Michael; Gude, Natalie A.; Sundararaman, Balaji; Joyo, Eri; Joyo, Anya Y.; Collins, Brett; Din, Shabana; Mohsin, Sadia; Uchida, Takafumi; Sussman, Mark A.

    2014-01-01

    Autologous c-kit+ cardiac progenitor cells (CPCs) are currently used in the clinic to treat heart disease. CPC-based regeneration may be further augmented by better understanding molecular mechanisms of endogenous cardiac repair and enhancement of pro-survival signaling pathways that antagonize senescence while also increasing differentiation. The prolyl isomerase Pin1 regulates multiple signaling cascades by modulating protein folding and thereby activity and stability of phosphoproteins. In this study, we examine the heretofore unexplored role of Pin1 in CPCs. Pin1 is expressed in CPCs in vitro and in vivo and is associated with increased proliferation. Pin1 is required for cell cycle progression and loss of Pin1 causes cell cycle arrest in the G1 phase in CPCs, concomitantly associated with decreased expression of Cyclins D and B and increased expression of cell cycle inhibitors p53 and retinoblastoma (Rb). Pin1 deletion increases cellular senescence but not differentiation or cell death of CPCs. Pin1 is required for endogenous CPC response as Pin1 knock-out mice have a reduced number of proliferating CPCs after ischemic challenge. Pin1 overexpression also impairs proliferation and causes G2/M phase cell cycle arrest with concurrent down-regulation of Cyclin B, p53, and Rb. Additionally, Pin1 overexpression inhibits replicative senescence, increases differentiation, and inhibits cell death of CPCs, indicating that cell cycle arrest caused by Pin1 overexpression is a consequence of differentiation and not senescence or cell death. In conclusion, Pin1 has pleiotropic roles in CPCs and may be a molecular target to promote survival, enhance repair, improve differentiation, and antagonize senescence. PMID:24375406

  3. The anticancer plant triterpenoid, avicin D, regulates glucocorticoid receptor signaling: implications for cellular metabolism.

    PubMed

    Haridas, Valsala; Xu, Zhi-Xiang; Kitchen, Doug; Jiang, Anna; Michels, Peter; Gutterman, Jordan U

    2011-01-01

    Avicins, a family of apoptotic triterpene electrophiles, are known to regulate cellular metabolism and energy homeostasis, by targeting the mitochondria. Having evolved from "ancient hopanoids," avicins bear a structural resemblance with glucocorticoids (GCs), which are the endogenous regulators of metabolism and energy balance. These structural and functional similarities prompted us to compare the mode of action of avicin D with dexamethasone (Dex), a prototypical GC. Using cold competition assay, we show that Avicin D competes with Dex for binding to the GC receptor (GR), leading to its nuclear translocation. In contrast to Dex, avicin-induced nuclear translocation of GR does not result in transcriptional activation of GC-dependent genes. Instead we observe a decrease in the expression of GC-dependent metabolic proteins such as PEPCK and FASN. However, like Dex, avicin D treatment does induce a transrepressive effect on the pro-inflammatory transcription factor NF-κB. While avicin's ability to inhibit NF-κB and its downstream targets appear to be GR-dependent, its pro-apoptotic effects were independent of GR expression. Using various deletion mutants of GR, we demonstrate the requirement of both the DNA and ligand binding domains of GR in mediating avicin D's transrepressive effects. Modeling of avicin-GR interaction revealed that avicin molecule binds only to the antagonist confirmation of GR. These findings suggest that avicin D has properties of being a selective GR modulator that separates transactivation from transrepression. Since the gene-activating properties of GR are mainly linked to its metabolic effects, and the negative interference with the activity of transcription factors to its anti-inflammatory and immune suppressive effects, the identification of such a dissociated GR ligand could have great potential for therapeutic use. PMID:22132201

  4. Conserved cellular function and stress-mediated regulation among members of the proteolipid protein family.

    PubMed

    Fernández, María E; Alfonso, Julieta; Brocco, Marcela A; Frasch, Alberto C

    2010-05-01

    Chronic stress causes morphological alterations in the hippocampus of rodents and tree shrews, including atrophy of CA3 dendrites and loss of synapses. The molecular mechanisms underlying these structural changes remain largely unknown. We have previously identified M6a as a stress responsive gene and shown that M6a is involved in filopodium/spine outgrowth and, likely, synapse formation. M6a belongs to the proteolipid protein (PLP) family, all of their members having four transmembrane domains that allow their localization at the plasma membrane. In the present work, we analyzed other members of this family, the closely related M6b as well as PLP and its splice variant DM20. We found that chronic restraint stress in mice reduces M6b and DM20, but not PLP, mRNA levels in the hippocampus. In addition, M6b and DM20, but again not PLP, induce filopodium formation in primary cultures of hippocampal neurons. Several M6b protein isoforms were studied, all of them having similar effects except for the one lacking the transmembrane domains. Our results reveal a conserved cellular function and a stress-mediated regulation among members of the proteolipid protein family, suggesting an involvement of proteolipid proteins in the stress response. PMID:19937804

  5. Reverse Signaling by Semaphorin-6A Regulates Cellular Aggregation and Neuronal Morphology

    PubMed Central

    Perez-Branguli, Francesc; Zagar, Yvrick; Shanley, Daniel K.; Graef, Isabella A.; Chédotal, Alain; Mitchell, Kevin J.

    2016-01-01

    The transmembrane semaphorin, Sema6A, has important roles in axon guidance, cell migration and neuronal connectivity in multiple regions of the nervous system, mediated by context-dependent interactions with plexin receptors, PlxnA2 and PlxnA4. Here, we demonstrate that Sema6A can also signal cell-autonomously, in two modes, constitutively, or in response to higher-order clustering mediated by either PlxnA2-binding or chemically induced multimerisation. Sema6A activation stimulates recruitment of Abl to the cytoplasmic domain of Sema6A and phos¡phorylation of this cytoplasmic tyrosine kinase, as well as phosphorylation of additional cytoskeletal regulators. Sema6A reverse signaling affects the surface area and cellular complexity of non-neuronal cells and aggregation and neurite formation of primary neurons in vitro. Sema6A also interacts with PlxnA2 in cis, which reduces binding by PlxnA2 of Sema6A in trans but not vice versa. These experiments reveal the complex nature of Sema6A biochemical functions and the molecular logic of the context-dependent interactions between Sema6A and PlxnA2. PMID:27392094

  6. 49 CFR Appendix C to Part 385 - Regulations Pertaining to Remedial Directives in Part 385, Subpart J

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Part 385, Subpart J C Appendix C to Part 385 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Pt. 385, App. C Appendix C to Part 385.... § 395.3(c)(1)Requiring or permitting a property-carrying commercial motor vehicle driver to restart...

  7. 49 CFR Appendix C to Part 385 - Regulations Pertaining to Remedial Directives in Part 385, Subpart J

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Part 385, Subpart J C Appendix C to Part 385 Transportation Other Regulations Relating to... MOTOR CARRIER SAFETY REGULATIONS SAFETY FITNESS PROCEDURES Pt. 385, App. C Appendix C to Part 385.... § 395.3(c)(1)Requiring or permitting a property-carrying commercial motor vehicle driver to restart...

  8. 12 CFR 1015.1 - Scope of regulations in this part.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Scope of regulations in this part. 1015.1 Section 1015.1 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION MORTGAGE ASSISTANCE RELIEF SERVICES (REGULATION O) § 1015.1 Scope of regulations in this part. This part, known as Regulation O, is issued by the Bureau of Consumer...

  9. Profiling human protein degradome delineates cellular responses to proteasomal inhibition and reveals a feedback mechanism in regulating proteasome homeostasis.

    PubMed

    Yu, Tao; Tao, Yonghui; Yang, Meiqiang; Chen, Peng; Gao, Xiaobo; Zhang, Yanbo; Zhang, Tao; Chen, Zi; Hou, Jian; Zhang, Yan; Ruan, Kangcheng; Wang, Hongyan; Hu, Ronggui

    2014-10-01

    Global change in protein turnover (protein degradome) constitutes a central part of cellular responses to intrinsic or extrinsic stimuli. However, profiling protein degradome remains technically challenging. Recently, inhibition of the proteasome, e.g., by using bortezomib (BTZ), has emerged as a major chemotherapeutic strategy for treating multiple myeloma and other human malignancies, but systematic understanding of the mechanisms for BTZ drug action and tumor drug resistance is yet to be achieved. Here we developed and applied a dual-fluorescence-based Protein Turnover Assay (ProTA) to quantitatively profile global changes in human protein degradome upon BTZ-induced proteasomal inhibition. ProTA and subsequent network analyses delineate potential molecular basis for BTZ action and tumor drug resistance in BTZ chemotherapy. Finally, combined use of BTZ with drugs targeting the ProTA-identified key genes or pathways in BTZ action reduced BTZ resistance in multiple myeloma cells. Remarkably, BTZ stabilizes proteasome subunit PSMC1 and proteasome assembly factor PSMD10, suggesting a previously under-appreciated mechanism for regulating proteasome homeostasis. Therefore, ProTA is a novel tool for profiling human protein degradome to elucidate potential mechanisms of drug action and resistance, which might facilitate therapeutic development targeting proteostasis to treat human disorders. PMID:25223703

  10. Hormone-regulated v-rel estrogen receptor fusion protein: reversible induction of cell transformation and cellular gene expression.

    PubMed

    Boehmelt, G; Walker, A; Kabrun, N; Mellitzer, G; Beug, H; Zenke, M; Enrietto, P J

    1992-12-01

    We describe the construction of a v-rel estrogen receptor fusion protein (v-relER) which allows the regulation of v-rel oncoprotein activity by hormone. In the presence of estrogen, v-relER readily transformed primary chicken fibroblasts and bone marrow cells in vitro. In both cell types, v-rel-specific transformation was critically dependent on the presence of estrogen or the estrogen agonist 4-hydroxytamoxifen (OHT). Withdrawal of estrogen or application of an estrogen antagonist, ICI164,384 (ICI) caused a reversal of the transformed phenotype. We also demonstrate that the v-relER protein binds to NF-kappa B sites in an estrogen-dependent manner, thereby showing that sequence-specific DNA binding of v-relER is critical for the activation of its transforming capacity. In transient transfection experiments, we failed to demonstrate a clear repressor or activator function of the v-rel moiety in v-relER. However, in v-relER-transformed bone marrow cells, estrogen and OHT induced elevated mRNA levels of two cellular genes whose expression is constitutive and high in v-rel-transformed cells. These results suggest that v-rel might exert part of its activity as an activator of rel-responsive genes. PMID:1425595

  11. Identification of Cellular Calcium Binding Protein Calmodulin as a Regulator of Rotavirus A Infection during Comparative Proteomic Study

    PubMed Central

    Chattopadhyay, Shiladitya; Basak, Trayambak; Nayak, Mukti Kant; Bhardwaj, Gourav; Mukherjee, Anupam; Bhowmick, Rahul; Sengupta, Shantanu; Chakrabarti, Oishee; Chatterjee, Nabendu S.; Chawla-Sarkar, Mamta

    2013-01-01

    Rotavirus (RV) being the major diarrhoegenic virus causes around 527000 children death (<5years age) worldwide. In cellular environment, viruses constantly adapt and modulate to survive and replicate while the host cell also responds to combat the situation and this results in the differential regulation of cellular proteins. To identify the virus induced differential expression of proteins, 2D-DIGE (Two-dimensional Difference Gel Electrophoresis) based proteomics was used. For this, HT-29 cells were infected with RV strain SA11 for 0 hours, 3 hours and 9 hours post infection (hpi), differentially expressed spots were excised from the gel and identified using MALDI-TOF/TOF mass spectrometry. 2D-DIGE based proteomics study identified 32 differentially modulated proteins, of which 22 were unique. Some of these were validated in HT-29 cell line and in BALB/c mice model. One of the modulated cellular proteins, calmodulin (CaM) was found to directly interact with RV protein VP6 in the presence of Ca2+. Ca2+-CaM/VP6 interaction positively regulates RV propagation since both CaM inhibitor (W-7) and Ca2+ chelator (BAPTA-AM) resulted in decreased viral titers. This study not only identifies differentially modulated cellular proteins upon infection with rotavirus in 2D-DIGE but also confirmed positive engagement of cellular Ca2+/CaM during viral pathogenesis. PMID:23437200

  12. Ebi, a Drosophila homologue of TBL1, regulates the balance between cellular defense responses and neuronal survival

    PubMed Central

    Lim, Young-Mi; Tsuda, Leo

    2016-01-01

    Transducin β-like 1 (TBL1), a transcriptional co-repressor complex, is a causative factor for late-onset hearing impairments. Transcriptional co-repressor complexes play pivotal roles in gene expression by making a complex with divergent transcription factors. However, it remained to be clarified how co-repressor complex regulates cellular survival. We herein demonstrated that ebi, a Drosophila homologue of TBL1, suppressed photoreceptor cell degeneration in the presence of excessive innate immune signaling. We also showed that the balance between NF-κB and AP-1 is a key component of cellular survival under stress conditions. Given that Ebi plays an important role in innate immune responses by regulating NF-κB activity and inhibition of apoptosis induced by associating with AP-1, it may be involved in the regulation of photoreceptor cell survival by modulating cross-talk between NF-κB and AP-1. PMID:27073743

  13. Dioscorea alata Attenuates Renal Interstitial Cellular Fibrosis by Regulating Smad- and Epithelial-Mesenchymal Transition Signaling Pathways

    PubMed Central

    Liu, Shu-Fen; Chang, Shan-Yu; Lee, Tao-Chen; Chuang, Lea-Yea; Guh, Jinn-Yuh; Hung, Chien-Ya; Hung, Tsung-Jen; Hung, Yu-Ju; Chen, Po-Yi; Hsieh, Pei-fang; Yang, Yu-Lin

    2012-01-01

    Renal interstitial fibrosis is characterized by increased extracellular matrix (ECM) synthesis. Epithelial-mesenchymal transition (EMT) in kidneys is driven by regulated expression of fibrogenic cytokines such as transforming growth factor-beta (TGF-β). Yam, or Dioscorea alata (DA) is an important herb in Chinese medicine widely used for the treatment of clinical diabetes mellitus. However, the fibrosis regulatory effect of DA is unclear. Thus, we examined TGF-β signaling mechanisms against EMT in rat fibroblast cells (NRK-49F). The characterization of DA water-extracts used various methods; after inducing cellular fibrosis in NRK-49F cells by treatment with β-hydroxybutyrate (β-HB) (10 mM), we used Western blotting to examine the protein expression in the TGF-β-related signal protein type I and type II TGF-β receptors, Smads2 and Smad3 (Smad2/3), pSmad2 and Smad3 (pSmad2/3), Smads4, Smads7, and EMT markers. These markers included E-cadherin, alpha-smooth muscle actin (α-SMA), and matrix metalloproteinase-2 (MMP-2). Bioactive TGF-β and fibronectin levels in the culture media were determined using ELISA. Expressions of fibronectin and Snail transcription factor, an EMT-regulatory transcription factor, were assessed by immunofluorescence staining. DA extract dose-dependently (50–200 µg/mL) suppressed β-HB-induced expression of fibronectin in NRK-49F cells concomitantly with the inhibition of Smad2/3, pSmad2/3, and Smad4. By contrast, Smad7 expression was significantly increased. DA extract caused a decrease in α-SMA (α-smooth muscle actin) and MMP-2 levels, and an increase in E-cadherin expression. We propose that DA extract might act as a novel fibrosis antagonist, which acts partly by down regulating the TGF-β/smad signaling pathway and modulating EMT expression. PMID:23144821

  14. Comparative Analysis of Nuclear Transfer Embryo-Derived Mouse Embryonic Stem Cells. Part I: Cellular Characterization

    PubMed Central

    Kobolak, Julianna; Mamo, Solomon; Rungsiwiwut, Ruttachuk; Ujhelly, Olga; Csonka, Erika; Hadlaczky, Gyula

    2012-01-01

    Abstract Embryonic stem cells derived from nuclear transfer embryos (ntESCs) are particularly valuable for regenerative medicine, as they are a patient-specific and histocompatible cell source for the treatment of varying diseases. However, currently, little is known about their cellular and molecular profile. In the present study, in a mouse model different donor cell-derived ntESCs from various genetic backgrounds were compared with reference ESCs and analyzed comprehensively at the cellular level. A number of pluripotency marker genes were compared by flow cytometry and immunocytochemistry analysis. Significant differences at the protein level were observed for POU5F1, SOX2, FGF4, NANOG, and SSEA-1. However, such differences had no effect on in vitro cell differentiation and cell fate: derivatives of the three germ layers were detected in all ntESC lines. The neural and cardiac in vitro differentiation revealed minor differences between the cell lines, both at the mRNA and protein level. Karyotype analyses and cell growth studies did not reveal any significant variations. Despite some differences observed, the present study revealed that ntESC lines had similar differentiation competences compared to other ESCs. The results indicate that the observed differences may be related to the genotype rather than to the nuclear transfer technology. PMID:22204592

  15. Selective transcriptional regulation by Myc in cellular growth control and lymphomagenesis

    PubMed Central

    de Pretis, Stefano; Gorski, Marcin M.; Tesi, Alessandra; Morelli, Marco J.; Bora, Pranami; Doni, Mirko; Verrecchia, Alessandro; Tonelli, Claudia; Fagà, Giovanni; Bianchi, Valerio; Ronchi, Alberto; Low, Diana; Müller, Heiko; Guccione, Ernesto; Campaner, Stefano; Amati, Bruno

    2014-01-01

    The c-myc proto-oncogene product, Myc, is a transcription factor that binds thousands of genomic loci1. Recent work suggested that rather than up- and down-regulating selected groups of genes1-3, Myc targets all active promoters and enhancers in the genome (a phenomenon termed “invasion”) and acts as a general amplifier of transcription4,5. However, the available data did not readily discriminate between direct and indirect effects of Myc on RNA biogenesis. We addressed this issue with genome-wide chromatin immunoprecipitation and RNA expression profiles during B-cell lymphomagenesis in mice, in cultured B-cells and fibroblasts. Consistent with long-standing observations6, we detected general increases in total RNA or mRNA copies per cell (hereby termed “amplification”)4,5 when comparing actively proliferating cells with control quiescent cells: this was true whether cells were stimulated by mitogens (requiring endogenous Myc for a proliferative response)7,8 or by deregulated, oncogenic Myc activity. RNA amplification and promoter/enhancer invasion by Myc were separable phenomena that could occur without one another. Moreover, whether or not associated with RNA amplification, Myc drove the differential expression of distinct subsets of target genes. Hence, while having the potential to interact with all active/poised regulatory elements in the genome4,5,9-11, Myc does not directly act as a global transcriptional amplifier4,5. Instead, our results imply that Myc activates and represses transcription of discrete gene sets, leading to changes in cellular state that can in turn feed back on global RNA production and turnover. PMID:25043028

  16. Ceramidases: regulators of cellular responses mediated by ceramide, sphingosine, and sphingosine-1-phosphate

    PubMed Central

    Mao, Cungui; Obeid, Lina M.

    2008-01-01

    Summary Ceramidases catalyze hydrolysis of ceramides to generate sphingosine (SPH), which is phosphorylated to form sphingosine-1-phosphate (S1P). Ceramide, SPH, and S1P are bioactive lipids that mediate cell proliferation, differentiation, apoptosis, adhesion, and migration, likely by controlling hydrolysis of ceramides and generation of SPH and S1P. Presently, 5 human ceramidases encoded by 5 distinct genes have been cloned: acid ceramidase (AC), neutral ceramidase (NC), alkaline ceramidase 1 (ACER1), alkaline ceramidase 2 (ACER2), and alkaline ceramidase 3 (ACER3). Each human ceramidase has a mouse counterpart. AC, NC, and ACER1–3 have maximal activities in acidic, neutral, and alkaline environments, respectively. ACER1–3 have similar protein sequences but no homology to AC and NC. AC and NC also have distinct protein sequences. The human AC (hAC) was implicated in Farber disease, and hAC may be important for cell survival. The mouse AC (mAC) is needed for early embryo survival. NC is protective against inflammatory cytokines, and the mouse NC (mNC) is required for the catabolism of ceramides in the digestive tract. ACER1 is critical in mediating cell differentiation by controlling the generation of SPH and S1P and that ACER2’s role in cell proliferation and survival depends on its expression or the cell type in which it is found. Here, we discuss the role of each ceramidase in regulating cellular responses mediated by ceramides, SPH, and S1P. PMID:18619555

  17. Monoubiquitination of survival motor neuron regulates its cellular localization and Cajal body integrity.

    PubMed

    Han, Ke-Jun; Foster, Daniel; Harhaj, Edward W; Dzieciatkowska, Monika; Hansen, Kirk; Liu, Chang-Wei

    2016-04-01

    Low levels of the survival motor neuron (SMN) protein cause spinal muscular atrophy, the leading genetic disorder for infant mortality. SMN is ubiquitously expressed in various cell types and localizes in both the cytoplasm and the nucleus, where it concentrates in two subnuclear structures termed Cajal body (CB) and gems. In addition, SMN can also be detected in the nucleolus of neurons. Mechanisms that control SMN sorting in the cell remain largely unknown. Here, we report that the ubiquitin (Ub) ligase Itch directly interacts with and monoubiquitinates SMN. Monoubiquitination of SMN has a mild effect on promoting proteasomal degradation of SMN. We generated two SMN mutants, SMN(K0), in which all lysines are mutated to arginines and thereby abolishing SMN ubiquitination, and Ub-SMN(K0), in which a single Ub moiety is fused at the N-terminus of SMN(K0) and thereby mimicking SMN monoubiquitination. Immunostaining assays showed that SMN(K0) mainly localizes in the nucleus, whereas Ub-SMN(K0) localizes in both the cytoplasm and the nucleolus in neuronal SH-SY5Y cells. Interestingly, canonical CB foci and coilin/small nuclear ribonucleoprotein (snRNP) co-localization are significantly impaired in SH-SY5Y cells stably expressing SMN(K0) or Ub-SMN(K0). Thus, our studies discover that Itch monoubiquitinates SMN and monoubiquitination of SMN plays an important role in regulating its cellular localization. Moreover, mislocalization of SMN disrupts CB integrity and likely impairs snRNP maturation. PMID:26908624

  18. Regulation of viral and cellular gene expression by Kaposi's sarcoma-associated herpesvirus polyadenylated nuclear RNA.

    PubMed

    Rossetto, Cyprian C; Tarrant-Elorza, Margaret; Verma, Subhash; Purushothaman, Pravinkumar; Pari, Gregory S

    2013-05-01

    Kaposi's sarcoma-associated herpesvirus (KSHV) is the cause of Kaposi's sarcoma and body cavity lymphoma. In cell culture, KSHV results in a latent infection, and lytic reactivation is usually induced with the expression of K-Rta or by treatment with phorbol 12-myristate 13-acetate (TPA) and/or n-butyrate. Lytic infection is marked by the activation of the entire viral genomic transcription cascade and the production of infectious virus. KSHV-infected cells express a highly abundant, long, noncoding transcript referred to as polyadenylated nuclear RNA (PAN RNA). PAN RNA interacts with specific demethylases and physically binds to the KSHV genome to mediate activation of viral gene expression. A recombinant BACmid lacking the PAN RNA locus fails to express K-Rta and does not produce virus. We now show that the lack of PAN RNA expression results in the failure of the initiation of the entire KSHV transcription program. In addition to previous findings of an interaction with demethylases, we show that PAN RNA binds to protein components of Polycomb repression complex 2 (PRC2). RNA-Seq analysis using cell lines that express PAN RNA shows that transcription involving the expression of proteins involved in cell cycle, immune response, and inflammation is dysregulated. Expression of PAN RNA in various cell types results in an enhanced growth phenotype, higher cell densities, and increased survival compared to control cells. Also, PAN RNA expression mediates a decrease in the production of inflammatory cytokines. These data support a role for PAN RNA as a major global regulator of viral and cellular gene expression. PMID:23468496

  19. SIRT1-dependent regulation of chromatin and transcription: linking NAD(+) metabolism and signaling to the control of cellular functions.

    PubMed

    Zhang, Tong; Kraus, W Lee

    2010-08-01

    Sirtuins comprise a family of NAD(+)-dependent protein deacetylases and ADP-ribosyltransferases. Mammalian SIRT1 - a homolog of yeast Sir2, the prototypical member of the sirtuin family - is an important regulator of metabolism, cell differentiation and senescence, stress response, and cancer. As an NAD(+)-dependent enzyme, SIRT1 regulates gene expression programs in response to cellular metabolic status, thereby coordinating metabolic adaptation of the whole organism. Several important mechanisms have emerged for SIRT1-dependent regulation of transcription. First, SIRT1 can modulate chromatin function through direct deacetylation of histones as well as by promoting alterations in the methylation of histones and DNA, leading to the repression of transcription. The latter is accomplished through the recruitment of other nuclear enzymes to chromatin for histone methylation and DNA CpG methylation, suggesting a broader role of SIRT1 in epigenetic regulation. Second, SIRT1 can interact and deacetylate a broad range of transcription factors and coregulators, thereby regulating target gene expression both positively and negatively. Cellular energy state, specifically NAD(+) metabolism, plays a major role in the regulation of SIRT1 activity. Recent studies on the NAD(+) biosynthetic enzymes in the salvage pathway, nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase 1 (NMNAT-1), have revealed important functions for these enzymes in SIRT1-dependent transcription regulation. The collective molecular actions of SIRT1 control specific patterns of gene expression that modulate a wide variety of physiological outcomes. PMID:19879981

  20. 18 CFR 410.1 - Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER CODE AND ADMINISTRATIVE MANUAL-PART...

  1. Transcriptional and post-transcriptional regulation of HIV-1 gene expression: role of cellular factors for Tat and Rev.

    PubMed

    Nekhai, Sergei; Jeang, Kuan-Teh

    2006-12-01

    The emergence of drug-resistant HIV-1 strains presents a challenge for the design of new therapy. Targeting host cell factors that regulate HIV-1 replication might be one way to overcome the propensity for HIV-1 to mutate in order to develop resistance to antivirals. This article reviews the interplay between viral proteins Tat and Rev and their cellular cofactors in the transcriptional and post-transcriptional regulation of HIV-1 gene expression. HIV-1 Tat regulates viral transcription by recruiting cellular factors to the HIV promoter. Tat interacts with protein kinase complexes Cdk9/cyclin T1 and Cdk2/cyclin E; acetyltransferases p300/CBP, p300/CBP-associated factor and hGCN5; protein phosphatases and other factors. HIV-1 Rev regulates post-transcriptional processing of viral mRNAs. Rev primarily functions to export unspliced and partially spliced viral RNAs from the nucleus into the cytoplasm. For this activity, Rev cooperates with cellular transport protein CRM1 and RNA helicases DDX1 and DDX3, amongst others. PMID:17661632

  2. PDX1, a cellular homeoprotein, binds to and regulates the activity of human cytomegalovirus immediate early promoter.

    PubMed

    Chao, Sheng-Hao; Harada, Josephine N; Hyndman, Francie; Gao, Xiaoqi; Nelson, Christian G; Chanda, Sumit K; Caldwell, Jeremy S

    2004-04-16

    Cellular homeoproteins have been shown to regulate the transcription of several viruses, including herpes simplex viruses, human papillomaviruses, and mouse mammary tumor viruses. Previous studies investigating the anti-viral mechanisms of several cyclin-dependent kinase inhibitors showed that the homeoproteins, pre B-cell leukemia transcription factor 1 (PBX1) and PBX-regulating protein-1 (PREP1), function as transcriptional activators of Moloney murine leukemia virus. Here, we examined the involvement of cellular homeoproteins in regulating the activity of the human cytomegalovirus immediate early (CMV IE) promoter. We identified a 45-bp element located at position -593 to -549 upstream of the transcription start site of the CMV IE gene, which contains multiple putative homeoprotein binding motifs. Gel shift assays demonstrated the physical association between a homeodomain protein, pancreatic-duodenal homeobox factor-1 (PDX1) and the 45-bp cytomegalovirus (CMV) region. We further determined that PDX1 represses the CMV IE promoter activity in 293 cells. Overexpression of PDX1 resulted in a decrease in transcription of the CMV IE gene. Conversely, blocking PDX1 protein synthesis and mutating the PDX1 binding sites enhanced CMV IE-dependent transcription. Collectively, our results represent the first work demonstrating that a cellular homeoprotein, PDX1, may be a repressor involved in regulation of human CMV gene expression. PMID:14764605

  3. Regulation of Cellular Response Pattern to Phosphorus Ion is a New Target for the Design of Tissue-Engineered Blood Vessel.

    PubMed

    Chen, Wen; Wang, Fangjuan; Zeng, Wen; Sun, Jun; Li, Li; Yang, Mingcan; Sun, Jiansen; Wu, Yangxiao; Zhao, Xiaohui; Zhu, Chuhong

    2015-05-01

    Regulation of cellular response pattern to phosphorus ion (PI) is a new target for the design of tissue-engineered materials. Changing cellular response pattern to high PI can maintain monocyte/macrophage survival in TEBV and the signal of increasing PI can be converted by klotho to the adenosine signals through the regulation of energy metabolism in monocytes/macrophages. PMID:25694105

  4. New perspectives on molecular and cellular mechanisms of neuroprotection and neuroregeneration: part I.

    PubMed

    Sharma, Hari Shanker; Sharma, Aruna

    2010-07-01

    Recent developments in the rapidly advancing area of neuroprotection and neuroregeneration necessitated the need to gather over 50 of the world's leading experts under the umbrella of the Global College of Neuroprotection and Neuroregeneration (GCNN) in its 7th Annual Meeting in Stockholm, Sweden. In this meeting, top policy-makers, together with world leaders in pharmaceutical industries, discussed the urgent need to develop new pharmaceuticals, as well as using a combination of existing ones, to treat CNS disorders in order to improve the current status of healthcare. In addition, nanobiotechnologists proposed the use of a new formulation of drugs using nanotechnologies for enhanced drug delivery to the brain for better therapeutic efficacy of the neuroprotective agents. The deliberations in this meeting provide new perspectives on the molecular and cellular mechanisms of neuroprotection and neuroregeneration that could be utilized to improve the existing healthcare for the benefit of mankind. PMID:20586687

  5. New perspectives on molecular and cellular mechanisms of neuroprotection and neuroregeneration: part II.

    PubMed

    Sharma, Hari Shanker; Sharma, Aruna

    2010-08-01

    Recent developments in the rapidly advancing area of neuroprotection and neuroregeneration necessitated the need to gather over 50 of the world's leading experts under the umbrella of the Global College of Neuroprotection and Neuroregeneration in its 7th Annual Meeting in Stockholm, Sweden. In this meeting, top policy-makers, together with world leaders in pharmaceutical industries, discussed the urgent need to develop new pharmaceuticals, as well as using a combination of existing ones, to treat CNS disorders in order to improve the current status of healthcare. In addition, nanobiotechnologists proposed the use of a new formulation of drugs using nanotechnologies for enhanced drug delivery to the brain for better therapeutic efficacy of the neuroprotective agents. The deliberations in this meeting provide new perspectives on the molecular and cellular mechanisms of neuroprotection and neuroregeneration that could be utilized to improve the existing healthcare for the benefit of mankind. PMID:20662749

  6. 18 CFR 410.1 - Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation...

  7. 75 FR 6186 - Information Collection Requirement; Defense Federal Acquisition Regulation Supplement; Part 205...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-08

    ... Defense Acquisition Regulations System Information Collection Requirement; Defense Federal Acquisition Regulation Supplement; Part 205, Publicizing Contract Actions AGENCY: Defense Acquisition Regulations System... approved information collection requirement. SUMMARY: In compliance with Section 3506(c)(2)(A) of...

  8. 75 FR 12518 - Information Collection Requirement; Defense Federal Acquisition Regulation Supplement; Part 237...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-16

    ... Defense Acquisition Regulations System Information Collection Requirement; Defense Federal Acquisition Regulation Supplement; Part 237, Service Contracting AGENCY: Defense Acquisition Regulations System... approved information collection requirement. SUMMARY: In compliance with Section 3506(c)(2)(A) of...

  9. 75 FR 20825 - Information Collection Requirement; Defense Federal Acquisition Regulation Supplement; Part 211...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-21

    ... Defense Acquisition Regulations System Information Collection Requirement; Defense Federal Acquisition Regulation Supplement; Part 211, Describing Agency Needs AGENCY: Defense Acquisition Regulations System... approved information collection requirement. SUMMARY: In compliance with Section 3506(c)(2)(A) of...

  10. 20 CFR 216.3 - Other regulations related to this part.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Other regulations related to this part. 216.3 Section 216.3 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT ELIGIBILITY FOR AN ANNUITY General § 216.3 Other regulations related to this part. This part is related to...

  11. 20 CFR 222.3 - Other regulations related to this part.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Other regulations related to this part. 222.3 Section 222.3 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT FAMILY RELATIONSHIPS General § 222.3 Other regulations related to this part. This part is related to...

  12. 34 CFR 222.19 - What other statutes and regulations apply to this part?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the basis of sex), and the implementing regulations (34 CFR part 106). (Authority: 20 U.S.C. 1681-1683...), and the implementing regulations (34 CFR part 100). (Authority: 42 U.S.C. 2000d—2000d-4) (2) The... discrimination on the basis of disability), and the implementing regulations (34 CFR part 104). (Authority: 29...

  13. 34 CFR 222.19 - What other statutes and regulations apply to this part?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... discrimination on the basis of disability), and the implementing regulations (34 CFR part 104). (Authority: 29 U...), and the implementing regulations (34 CFR part 100). (Authority: 42 U.S.C. 2000d—2000d-4) (2) The... the basis of sex), and the implementing regulations (34 CFR part 106). (Authority: 20 U.S.C....

  14. 34 CFR 222.19 - What other statutes and regulations apply to this part?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the basis of sex), and the implementing regulations (34 CFR part 106). (Authority: 20 U.S.C. 1681-1683...), and the implementing regulations (34 CFR part 100). (Authority: 42 U.S.C. 2000d—2000d-4) (2) The... discrimination on the basis of disability), and the implementing regulations (34 CFR part 104). (Authority: 29...

  15. 34 CFR 222.19 - What other statutes and regulations apply to this part?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the basis of sex), and the implementing regulations (34 CFR part 106). (Authority: 20 U.S.C. 1681-1683...), and the implementing regulations (34 CFR part 100). (Authority: 42 U.S.C. 2000d—2000d-4) (2) The... discrimination on the basis of disability), and the implementing regulations (34 CFR part 104). (Authority: 29...

  16. E2F transcription factor 1 regulates cellular and organismal senescence by inhibiting Forkhead box O transcription factors.

    PubMed

    Xie, Qi; Peng, Shengyi; Tao, Li; Ruan, Haihe; Yang, Yanglu; Li, Tie-Mei; Adams, Ursula; Meng, Songshu; Bi, Xiaolin; Dong, Meng-Qiu; Yuan, Zengqiang

    2014-12-01

    E2F1 and FOXO3 are two transcription factors that have been shown to participate in cellular senescence. Previous report reveals that E2F1 enhanced cellular senescence in human fibroblast cells, while FOXO transcription factors play against senescence by regulation reactive oxygen species scavenging proteins. However, their functional interplay has been unclear. Here we use E2F1 knock-out murine Embryonic fibroblasts (MEFs), knockdown RNAi constructs, and ectopic expression of E2F1 to show that it functions by negatively regulating FOXO3. E2F1 attenuates FOXO3-mediated expression of MnSOD and Catalase without affecting FOXO3 protein stability, subcellular localization, or phosphorylation by Akt. We mapped the interaction between E2F1 and FOXO3 to a region including the DNA binding domain of E2F1 and the C-terminal transcription-activation domain of FOXO3. We propose that E2F1 inhibits FOXO3-dependent transcription by directly binding FOXO3 in the nucleus and preventing activation of its target genes. Moreover, knockdown of the Caenorhabditis elegans E2F1 ortholog efl-1 significantly extends lifespan in a manner that requires the activity of the C. elegans FOXO gene daf-16. We conclude that there is an evolutionarily conserved signaling connection between E2F1 and FOXO3, which regulates cellular senescence and aging by regulating the activity of FOXO3. We speculate that drugs and/or therapies that inhibit this physical interaction might be good candidates for reducing cellular senescence and increasing longevity. PMID:25344604

  17. DNMT3a epigenetic program regulates the HIF-2α oxygen-sensing pathway and the cellular response to hypoxia

    PubMed Central

    Lachance, Gabriel; Uniacke, James; Audas, Timothy E.; Holterman, Chet E.; Franovic, Aleksandra; Payette, Josianne; Lee, Stephen

    2014-01-01

    Epigenetic regulation of gene expression by DNA methylation plays a central role in the maintenance of cellular homeostasis. Here we present evidence implicating the DNA methylation program in the regulation of hypoxia-inducible factor (HIF) oxygen-sensing machinery and hypoxic cell metabolism. We show that DNA methyltransferase 3a (DNMT3a) methylates and silences the HIF-2α gene (EPAS1) in differentiated cells. Epigenetic silencing of EPAS1 prevents activation of the HIF-2α gene program associated with hypoxic cell growth, thereby limiting the proliferative capacity of adult cells under low oxygen tension. Naturally occurring defects in DNMT3a, observed in primary tumors and malignant cells, cause the unscheduled activation of EPAS1 in early dysplastic foci. This enables incipient cancer cells to exploit the HIF-2α pathway in the hypoxic tumor microenvironment necessary for the formation of cellular masses larger than the oxygen diffusion limit. Reintroduction of DNMT3a in DNMT3a-defective cells restores EPAS1 epigenetic silencing, prevents hypoxic cell growth, and suppresses tumorigenesis. These data support a tumor-suppressive role for DNMT3a as an epigenetic regulator of the HIF-2α oxygen-sensing pathway and the cellular response to hypoxia. PMID:24817692

  18. Parasitoid wasp venom SERCA regulates Drosophila calcium levels and inhibits cellular immunity

    PubMed Central

    Mortimer, Nathan T.; Goecks, Jeremy; Kacsoh, Balint Z.; Mobley, James A.; Bowersock, Gregory J.; Taylor, James; Schlenke, Todd A.

    2013-01-01

    Because parasite virulence factors target host immune responses, identification and functional characterization of these factors can provide insight into poorly understood host immune mechanisms. The fruit fly Drosophila melanogaster is a model system for understanding humoral innate immunity, but Drosophila cellular innate immune responses remain incompletely characterized. Fruit flies are regularly infected by parasitoid wasps in nature and, following infection, flies mount a cellular immune response culminating in the cellular encapsulation of the wasp egg. The mechanistic basis of this response is largely unknown, but wasps use a mixture of virulence proteins derived from the venom gland to suppress cellular encapsulation. To gain insight into the mechanisms underlying wasp virulence and fly cellular immunity, we used a joint transcriptomic/proteomic approach to identify venom genes from Ganaspis sp.1 (G1), a previously uncharacterized Drosophila parasitoid species, and found that G1 venom contains a highly abundant sarco/endoplasmic reticulum calcium ATPase (SERCA) pump. Accordingly, we found that fly immune cells termed plasmatocytes normally undergo a cytoplasmic calcium burst following infection, and that this calcium burst is required for activation of the cellular immune response. We further found that the plasmatocyte calcium burst is suppressed by G1 venom in a SERCA-dependent manner, leading to the failure of plasmatocytes to become activated and migrate toward G1 eggs. Finally, by genetically manipulating plasmatocyte calcium levels, we were able to alter fly immune success against G1 and other parasitoid species. Our characterization of parasitoid wasp venom proteins led us to identify plasmatocyte cytoplasmic calcium bursts as an important aspect of fly cellular immunity. PMID:23690612

  19. Regulation of cellular manganese and manganese transport rates in the unicellular alga Chlamydomonas

    SciTech Connect

    Sunda, W.G.; Huntsman, S.A.

    1985-01-01

    The cellular accumulation and uptake kinetics of manganese by Chlamydomonas sp. were studied in model chelate buffer systems. Cellular manganese concentrations and uptake rates were related to the computed free manganese ion concentration and were independent of the total or chelated manganese concentration. Cellular manganese was constant at about 1 mmol liter/sup -1/ of cellular volume at free manganese ion concentrations of 10/sup -7/ /sup 6/-10/sup -6/ /sup 3/ mol liter/sup -1/ and decreased below this range. Manganese uptake rates followed saturation kinetics and V/sub max/, but not K/sub s/, varied with the free manganese ion concentration in the growth medium. V/sub max/ appeared to be under negative feedback control and increased with decreasing manganese ion concentration. Variations of up to 30-fold in this parameter seemed to be instrumental in limiting the variation in cellular manganese to a sixfold range despite a 1000-fold variation in free manganese ion concentration in the growth medium.

  20. SCFFbw7 Regulates Cellular Apoptosis By Targeting Mcl-1 for Ubiquitination and Destruction

    PubMed Central

    Inuzuka, Hiroyuki; Shaik, Shavali; Onoyama, Ichiro; Gao, Daming; Tseng, Alan; Maser, Richard S.; Zhai, Bo; Wan, Lixin; Gutierrez, Alejandro; Lau, Alan W.; Xiao, Yonghong; Christie, Amanda L.; Aster, Jon; Settleman, Jeffrey; Gygi, Steven P.; Kung, Andrew L.; Look, Thomas; Nakayama, Keiichi I.; DePinho, Ronald A.; Wei, Wenyi

    2010-01-01

    The effective use of targeted therapy is highly dependent upon the identification of responder patient populations. Loss of the Fbw7 tumor suppressor is frequently found in various types of human cancers including breast cancer, colon cancer 1 and T-cell acute lymphoblastic leukemia (T-ALL)2. In line with these genomic data, engineered deletion of Fbw7 in mouse T cells results in T-ALL3–5, validating Fbw7 as a T-ALL tumor suppressor. The precise molecular mechanisms by which Fbw7 exerts anti-tumor activity remain areas of intensive investigation and are thought to relate in part to Fbw7-mediated destruction of key cancer relevant proteins including c-Jun6, c-Myc 7, Cyclin E 8 and Notch-19, all of which possess oncogenic activity and are overexpressed in various human cancers including leukemia. Besides accelerating cell growth 10, overexpression of either c-Jun, c-Myc or Notch-1 can also provoke programmed cell death 11. Thus, considerable uncertainty surrounds how Fbw7-deficient cells evade cell death in the setting of upregulated c-Jun, c-Myc and/or Notch-1. Here we report that SCFFbw7 governs cellular apoptosis by targeting the pro-survival Bcl-2 family member, Mcl-1, for ubiquitination and destruction in a GSK3 phosphorylation-dependent manner. Human T-ALL cell lines showed a close relationship between Fbw7 loss and Mcl-1 overexpression. Correspondingly, T-ALL cell lines with defective Fbw7 are particularly sensitive to the multi-kinase inhibitor, sorafenib, but resistant to the Bcl-2 antagonist, ABT-737. On the genetic level, Fbw7 reconstitution or Mcl-1 depletion restores ABT-737 sensitivity, establishing Mcl-1 as a therapeutically relevant bypass survival mechanism for Fbw7-deficient cells to evade apoptosis. Therefore, our work provides novel molecular insight into Fbw7-direct tumor suppression with direct implications for the targeted treatment of Fbw7-deficient T-ALL patients. PMID:21368833

  1. 17 CFR 210.1-01 - Application of Regulation S-X (17 CFR part 210).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... POLICY AND CONSERVATION ACT OF 1975 Application of Regulation S-X (17 Cfr Part 210) § 210.1-01 Application of Regulation S-X (17 CFR part 210). (a) This part (together with the Financial Reporting Releases... (17 CFR part 210). 210.1-01 Section 210.1-01 Commodity and Securities Exchanges SECURITIES...

  2. 17 CFR 210.1-01 - Application of Regulation S-X (17 CFR part 210).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... POLICY AND CONSERVATION ACT OF 1975 Application of Regulation S-X (17 Cfr Part 210) § 210.1-01 Application of Regulation S-X (17 CFR part 210). (a) This part (together with the Financial Reporting Releases... (17 CFR part 210). 210.1-01 Section 210.1-01 Commodity and Securities Exchanges SECURITIES...

  3. 17 CFR 210.1-01 - Application of Regulation S-X (17 CFR part 210).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (17 Cfr Part 210) § 210.1-01 Application of Regulation S-X (17 CFR part 210). (a) This part (together... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Application of Regulation S-X (17 CFR part 210). 210.1-01 Section 210.1-01 Commodity and Securities Exchanges SECURITIES...

  4. 17 CFR 210.1-01 - Application of Regulation S-X (17 CFR part 210).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (17 Cfr Part 210) § 210.1-01 Application of Regulation S-X (17 CFR part 210). (a) This part (together... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Application of Regulation S-X (17 CFR part 210). 210.1-01 Section 210.1-01 Commodity and Securities Exchanges SECURITIES...

  5. 17 CFR 210.1-01 - Application of Regulation S-X (17 CFR part 210).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... POLICY AND CONSERVATION ACT OF 1975 Application of Regulation S-X (17 Cfr Part 210) § 210.1-01 Application of Regulation S-X (17 CFR part 210). (a) This part (together with the Financial Reporting Releases... (17 CFR part 210). 210.1-01 Section 210.1-01 Commodity and Securities Exchanges SECURITIES...

  6. 31 CFR 551.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Relation of this part to other laws... REGULATIONS Relation of This Part to Other Laws and Regulations § 551.101 Relation of this part to other laws... to the public. OFAC intends to supplement this part with a more comprehensive set of...

  7. Regulation of biofilm formation and cellular buoyancy through modulating intracellular cyclic di-GMP levels in engineered cyanobacteria.

    PubMed

    Agostoni, Marco; Waters, Christopher M; Montgomery, Beronda L

    2016-02-01

    The second messenger cyclic dimeric (3'→5') GMP (cyclic di-GMP or c-di-GMP) has been implicated in the transition between motile and sessile lifestyles in bacteria. In this study, we demonstrate that biofilm formation, cellular aggregation or flocculation, and cellular buoyancy are under the control of c-di-GMP in Synechocystis sp. PCC 6803 (Synechocystis) and Fremyella diplosiphon. Synechocystis is a unicellular cyanobacterium and displays lower levels of c-di-GMP; F. diplosiphon is filamentous and displays higher intracellular c-di-GMP levels. We transformed Synechocystis and F. diplosiphon with a plasmid for constitutive expression of genes encoding diguanylate cylase (DGC) and phosphodiesterase (PDE) proteins from Vibrio cholerae or Escherichia coli, respectively. These engineered strains allowed us to modulate intracellular c-di-GMP levels. Biofilm formation and cellular deposition were induced in the DGC-expressing Synechocystis strain which exhibited high intracellular levels of c-di-GMP; whereas strains expressing PDE in Synechocystis and F. diplosiphon to drive low intracellular levels of c-di-GMP exhibited enhanced cellular buoyancy. In addition, the PDE-expressing F. diplosiphon strain showed elevated chlorophyll levels. These results imply roles for coordinating c-di-GMP homeostasis in regulating native cyanobacterial phenotypes. Engineering exogenous DGC or PDE proteins to regulate intracellular c-di-GMP levels represents an effective tool for uncovering cryptic phenotypes or modulating phenotypes in cyanobacteria for practical applications in biotechnology applicable in photobioreactors and in green biotechnologies, such as energy-efficient harvesting of cellular biomass or the treatment of metal-containing wastewaters. PMID:26192200

  8. Cellular Uptake and Cytotoxicity of Drug-Peptide Conjugates Regulated by Conjugation Site

    PubMed Central

    Zhang, Pengcheng; Cheetham, Andrew G.; Lock, Lye Lin; Cui, Honggang

    2013-01-01

    Conjugation of anticancer drugs to hydrophilic peptides such as Tat is a widely adopted strategy to improve the drug’s solubility, cellular uptake and potency against cancerous cells. Here we report that attachment of an anticancer drug doxorubicin to the N- or C-terminal of the Tat peptide can have a significant impact on their cellular uptake, cytotoxicity against both drug-sensitive and drug-resistant cancer cells. We observed higher cellular uptake by both cell lines for C-terminal conjugate relative to the N-terminal analogue. Our results reveal that the C-terminal conjugate partially overcame the multi-drug resistance of cervical cancer cells, while the N-terminal conjugate showed no significant improvement in cytotoxicity when compared with free doxorubicin. We also found that both N- and C- conjugates offers a mechanism to circumvent drug efflux associated with multidrug resistance. PMID:23514455

  9. Cellular Genes in the Mouse Regulate IN TRANS the Expression of Endogenous Mouse Mammary Tumor Viruses

    PubMed Central

    Traina-Dorge, Vicki L.; Carr, Jean K.; Bailey-Wilson, Joan E.; Elston, Robert C.; Taylor, Benjamin A.; Cohen, J. Craig

    1985-01-01

    The transcriptional activities of the eleven mouse mammary tumor virus (MMTV) proviruses endogenous to two sets of recombinant inbred (RI) mouse strains, BXD and BXH, were characterized. Comparison of the levels of virus-specific RNA quantitated in each strain showed no direct relationship between the presence of a particular endogenous provirus or with increasing numbers of proviruses. Association of specific genetic markers with the level of MMTV-specific RNA was examined by using multiple regression analysis. Several cellular loci as well as proviral loci were identified that were significantly associated with viral expression. Importantly, these cellular loci associated with MMTV expression segregated independently of viral sequences. PMID:2996982

  10. MicroRNAs Regulate Cellular ATP Levels by Targeting Mitochondrial Energy Metabolism Genes during C2C12 Myoblast Differentiation

    PubMed Central

    Siengdee, Puntita; Trakooljul, Nares; Murani, Eduard; Schwerin, Manfred; Wimmers, Klaus; Ponsuksili, Siriluck

    2015-01-01

    In our previous study, we identified an miRNA regulatory network involved in energy metabolism in porcine muscle. To better understand the involvement of miRNAs in cellular ATP production and energy metabolism, here we used C2C12 myoblasts, in which ATP levels increase during differentiation, to identify miRNAs modulating these processes. ATP level, miRNA and mRNA microarray expression profiles during C2C12 differentiation into myotubes were assessed. The results suggest 14 miRNAs (miR-423-3p, miR-17, miR-130b, miR-301a/b, miR-345, miR-15a, miR-16a, miR-128, miR-615, miR-1968, miR-1a/b, and miR-194) as cellular ATP regulators targeting genes involved in mitochondrial energy metabolism (Cox4i2, Cox6a2, Ndufb7, Ndufs4, Ndufs5, and Ndufv1) during C2C12 differentiation. Among these, miR-423-3p showed a high inverse correlation with increasing ATP levels. Besides having implications in promoting cell growth and cell cycle progression, its function in cellular ATP regulation is yet unknown. Therefore, miR-423-3p was selected and validated for the function together with its potential target, Cox6a2. Overexpression of miR-423-3p in C2C12 myogenic differentiation lead to decreased cellular ATP level and decreased expression of Cox6a2 compared to the negative control. These results suggest miR-423-3p as a novel regulator of ATP/energy metabolism by targeting Cox6a2. PMID:26010876

  11. 12 CFR 1014.1 - Scope of regulations in this part.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Scope of regulations in this part. 1014.1 Section 1014.1 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION MORTGAGE ACTS AND PRACTICES-ADVERTISING (REGULATION N) § 1014.1 Scope of regulations in this part. This part, known as Regulation N, is issued by the Bureau of Consumer...

  12. MicroRNA-mediated regulation of p21 and TASK1 cellular restriction factors enhances HIV-1 infection

    PubMed Central

    Farberov, Luba; Herzig, Eytan; Modai, Shira; Isakov, Ofer; Hizi, Amnon; Shomron, Noam

    2015-01-01

    MicroRNAs (miRNAs) are short non-coding RNAs that play a central role in the regulation of gene expression by binding to target mRNAs. Several studies have revealed alterations in cellular miRNA profiles following HIV-1 infection, mostly for miRNAs involved in inhibiting viral infection. These miRNA expression modifications might also serve to block the innate HIV-1 inhibition mechanism. As a result, it is expected that during HIV-1 infection miRNAs target genes that hinder or prevent the progression of the HIV-1 replication cycle. One of the major sets of genes known to inhibit the progression of HIV-1 infection are cellular restriction factors. In this study, we identified a direct miRNA target gene that modulates viral spread in T-lymphocytes and HeLa-CCR5 cell lines. Following infection, let-7c, miR-34a or miR-124a were upregulated, and they targeted and downregulated p21 and TASK1 (also known as CDKN1A and KCNK3, respectively) cellular proteins. This eventually led to increased virion release and higher copy number of viral genome transcripts in infected cells. Conversely, by downregulating these miRNAs, we could suppress viral replication and spread. Our data suggest that HIV-1 exploits the host miRNA cellular systems in order to block the innate inhibition mechanism, allowing a more efficient infection process. PMID:25717002

  13. 18 CFR 410.1 - Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Register under 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain or inspect a copy at the Delaware River... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation...

  14. 18 CFR 410.1 - Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Register under 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain or inspect a copy at the Delaware River... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation...

  15. 18 CFR 410.1 - Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Register under 5 U.S.C. 552(a) and 1 CFR part 51. You may obtain or inspect a copy at the Delaware River... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation...

  16. Cutaneous adverse effects of targeted therapies: Part I: Inhibitors of the cellular membrane.

    PubMed

    Macdonald, James B; Macdonald, Brooke; Golitz, Loren E; LoRusso, Patricia; Sekulic, Aleksandar

    2015-02-01

    There has been a rapid emergence of numerous targeted agents in the oncology community in the last decade. This exciting paradigm shift in drug development lends promise for the future of individualized medicine. Given the pace of development and clinical deployment of targeted agents with novel mechanisms of action, dermatology providers may not be familiar with the full spectrum of associated skin-related toxicities. Cutaneous adverse effects are among the most frequently observed toxicities with many targeted agents, and their intensity can be dose-limiting or lead to therapy discontinuation. In light of the often life-saving nature of emerging oncotherapeutics, it is critical that dermatologists both understand the mechanisms and recognize clinical signs and symptoms of such toxicities in order to provide effective clinical management. Part I of this continuing medical education article will review in detail the potential skin-related adverse sequelae, the frequency of occurrence, and the implications associated with on- and off-target cutaneous toxicities of inhibitors acting at the cell membrane level, chiefly inhibitors of epidermal growth factor receptor, KIT, and BCR-ABL, angiogenesis, and multikinase inhibitors. PMID:25592338

  17. 20 CFR 229.3 - Other regulations related to this part.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Other regulations related to this part. 229.3 Section 229.3 Employees' Benefits RAILROAD RETIREMENT BOARD REGULATIONS UNDER THE RAILROAD RETIREMENT ACT SOCIAL SECURITY OVERALL MINIMUM GUARANTEE General § 229.3 Other regulations related to this part....

  18. 31 CFR 510.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance:Treasury 3 2012-07-01 2012-07-01 false Relation of this part to other laws and regulations. 510.101 Section 510.101 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY NORTH KOREA SANCTIONS REGULATIONS Relation of This Part to...

  19. Mechanisms in photodynamic therapy: part one—-photosensitizers, photochemistry and cellular localization

    PubMed Central

    Castano, Ana P.; Demidova, Tatiana N.; Hamblin, Michael R.

    2013-01-01

    Summary The use of non-toxic dyes or photosensitizers (PS) in combination with harmless visible light that is known as photodynamic therapy (PDT) has been known for over a hundred years, but is only now becoming widely used. Originally developed as a tumor therapy, some of its most successful applications are for non-malignant disease. In a series of three reviews we will discuss the mechanisms that operate in the field of PDT. Part one discusses the recent explosion in discovery and chemical synthesis of new PS. Some guidelines on how to choose an ideal PS for a particular application are presented. The photochemistry and photophysics of PS and the two pathways known as Type I (radicals and reactive oxygen species) and Type II (singlet oxygen) photochemical processes are discussed. To carry out PDT effectively in vivo, it is necessary to ensure sufficient light reaches all the diseased tissue. This involves understanding how light travels within various tissues and the relative effects of absorption and scattering. The fact that most of the PS are also fluorescent allows various optical imaging and monitoring strategies to be combined with PDT. The most important factor governing the outcome of PDT is how the PS interacts with cells in the target tissue or tumor, and the key aspect of this interaction is the subcellular localization of the PS. Examples of PS that localize in mitochondria, lysosomes, endoplasmic reticulum, Golgi apparatus and plasma membranes are given. Finally the use of 5-aminolevulinic acid as a natural precursor of the heme biosynthetic pathway, stimulates accumulation of the PS protoporphyrin IX is described. PMID:25048432

  20. Sodium Glucose Cotransporter 2 (SGLT2) Plays as a Physiological Glucose Sensor and Regulates Cellular Contractility in Rat Mesangial Cells

    PubMed Central

    Wakisaka, Masanori; Nagao, Tetsuhiko; Yoshinari, Mototaka

    2016-01-01

    Purpose Mesangial cells play an important role in regulating glomerular filtration by altering their cellular tone. We report the presence of a sodium glucose cotransporter (SGLT) in rat mesangial cells. This study in rat mesangial cells aimed to evaluate the expression and role of SGLT2. Methods The SGLT2 expression in rat mesangial cells was assessed by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR). Changes in the mesangial cell surface area at different glucose concentrations and the effects of extracellular Na+ and Ca2+ and of SGLT and Na+/Ca2+ exchanger (NCX) inhibitors on cellular size were determined. The cellular sizes and the contractile response were examined during a 6-day incubation with high glucose with or without phlorizin, an SGLT inhibitor. Results Western blotting revealed an SGLT2 band, and RT-PCR analysis of SGLT2 revealed the predicted 422-bp band in both rat mesangial and renal proximal tubular epithelial cells. The cell surface area changed according to the extracellular glucose concentration. The glucose-induced contraction was abolished by the absence of either extracellular Na+ or Ca2+ and by SGLT and NCX inhibitors. Under the high glucose condition, the cell size decreased for 2 days and increased afterwards; these cells did not contract in response to angiotensin II, and the SGLT inhibitor restored the abolished contraction. Conclusions These data suggest that SGLT2 is expressed in rat mesangial cells, acts as a normal physiological glucose sensor and regulates cellular contractility in rat mesangial cells. PMID:26999015

  1. Topology regulates pattern formation capacity of binary cellular automata on graphs

    NASA Astrophysics Data System (ADS)

    Marr, Carsten; Hütt, Marc-Thorsten

    2005-08-01

    We study the effect of topology variation on the dynamic behavior of a system with local update rules. We implement one-dimensional binary cellular automata on graphs with various topologies by formulating two sets of degree-dependent rules, each containing a single parameter. We observe that changes in graph topology induce transitions between different dynamic domains (Wolfram classes) without a formal change in the update rule. Along with topological variations, we study the pattern formation capacities of regular, random, small-world and scale-free graphs. Pattern formation capacity is quantified in terms of two entropy measures, which for standard cellular automata allow a qualitative distinction between the four Wolfram classes. A mean-field model explains the dynamic behavior of random graphs. Implications for our understanding of information transport through complex, network-based systems are discussed.

  2. Myocardial Gene Transfer: Routes and Devices for Regulation of Transgene Expression by Modulation of Cellular Permeability

    PubMed Central

    Katz, Michael G.; Bridges, Charles R.

    2013-01-01

    Abstract Heart diseases are major causes of morbidity and mortality in Western society. Gene therapy approaches are becoming promising therapeutic modalities to improve underlying molecular processes affecting failing cardiomyocytes. Numerous cardiac clinical gene therapy trials have yet to demonstrate strong positive results and advantages over current pharmacotherapy. The success of gene therapy depends largely on the creation of a reliable and efficient delivery method. The establishment of such a system is determined by its ability to overcome the existing biological barriers, including cellular uptake and intracellular trafficking as well as modulation of cellular permeability. In this article, we describe a variety of physical and mechanical methods, based on the transient disruption of the cell membrane, which are applied in nonviral gene transfer. In addition, we focus on the use of different physiological techniques and devices and pharmacological agents to enhance endothelial permeability. Development of these methods will undoubtedly help solve major problems facing gene therapy. PMID:23427834

  3. 31 CFR 535.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Relation of this part to other laws... REGULATIONS Relation of This Part to Other Laws and Regulations § 535.101 Relation of this part to other laws... it is prohibited by reason of the provisions of any law or any statute other than the...

  4. 34 CFR Appendix A to Part 100 - Federal Financial Assistance to Which These Regulations Apply

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Apply A Appendix A to Part 100 Education Regulations of the Offices of the Department of Education.... 100, App. A Appendix A to Part 100—Federal Financial Assistance to Which These Regulations Apply Part...). 11. Research and training projects in Vocational Education (20 U.S.C. 1281(a), 1282-1284)....

  5. 40 CFR 1039.15 - Do any other regulation parts apply to me?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Do any other regulation parts apply to... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Overview and Applicability § 1039.15 Do any other regulation parts apply to me? (a) Part 1065 of this...

  6. 40 CFR 1051.15 - Do any other regulation parts apply to me?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Do any other regulation parts apply to... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM RECREATIONAL ENGINES AND VEHICLES Overview and Applicability § 1051.15 Do any other regulation parts apply to me? (a) Parts 86 and 1065 of this chapter...

  7. 31 CFR 535.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Relation of this part to other laws... REGULATIONS Relation of This Part to Other Laws and Regulations § 535.101 Relation of this part to other laws... it is prohibited by reason of the provisions of any law or any statute other than the...

  8. Evidence for transcriptional and post-translational regulation of sucrose synthase in pea nodules by the cellular redox state.

    PubMed

    Marino, Daniel; Hohnjec, Natalija; Küster, Helge; Moran, Jose F; González, Esther M; Arrese-Igor, Cesar

    2008-05-01

    Nitrogen fixation (NF) in legume nodules is very sensitive to environmental constraints. Nodule sucrose synthase (SS; EC 2.4.1.13) has been suggested to play a crucial role in those circumstances because its downregulation leads to an impaired glycolytic carbon flux and, therefore, a depletion of carbon substrates for bacteroids. In the present study, the likelihood of SS being regulated by oxidative signaling has been addressed by the in vivo supply of paraquat (PQ) to nodulated pea plants and the in vitro effects of oxidizing and reducing agents on nodule SS. PQ produced cellular redox imbalance leading to an inhibition of NF. This was preceded by the downregulation of SS gene expression, protein content, and activity. In vitro, oxidizing agents were able to inhibit SS activity and this inhibition was completely reversed by the addition of dithiothreitol. The overall results are consistent with a regulation model of nodule SS exerted by the cellular redox state at both the transcriptional and post-translational levels. The importance of such mechanisms for the regulation of NF in response to environmental stresses are discussed. PMID:18393622

  9. UV induced ubiquitination of the yeast Rad4-Rad23 complex promotes survival by regulating cellular dNTP pools.

    PubMed

    Zhou, Zheng; Humphryes, Neil; van Eijk, Patrick; Waters, Raymond; Yu, Shirong; Kraehenbuehl, Rolf; Hartsuiker, Edgar; Reed, Simon H

    2015-09-01

    Regulating gene expression programmes is a central facet of the DNA damage response. The Dun1 kinase protein controls expression of many DNA damage induced genes, including the ribonucleotide reductase genes, which regulate cellular dNTP pools. Using a combination of gene expression profiling and chromatin immunoprecipitation, we demonstrate that in the absence of DNA damage the yeast Rad4-Rad23 nucleotide excision repair complex binds to the promoters of certain DNA damage response genes including DUN1, inhibiting their expression. UV radiation promotes the loss of occupancy of the Rad4-Rad23 complex from the regulatory regions of these genes, enabling their induction and thereby controlling the production of dNTPs. We demonstrate that this regulatory mechanism, which is dependent on the ubiquitination of Rad4 by the GG-NER E3 ligase, promotes UV survival in yeast cells. These results support an unanticipated regulatory mechanism that integrates ubiquitination of NER DNA repair factors with the regulation of the transcriptional response controlling dNTP production and cellular survival after UV damage. PMID:26150418

  10. Andrographolide up-regulates cellular-reduced glutathione level and protects cardiomyocytes against hypoxia/reoxygenation injury.

    PubMed

    Woo, Anthony Y H; Waye, Mary M Y; Tsui, Stephen K W; Yeung, Sandy T W; Cheng, Christopher H K

    2008-04-01

    Recent studies revealed that the herb Andrographis paniculata possesses cardioprotective activities. Using neonatal rat cardiomyocytes, the cardioprotective actions of several diterpene lactones derived from A. paniculata including andrographolide, 14-deoxyandrographolide, 14-deoxy-11,12-didehydroandrographolide, and sodium 14-deoxyandrographolide-12-sulfonate were investigated. Pretreatment with andrographolide but not with the other compounds protected the cardiomyocytes against hypoxia/ reoxygenation injury and up-regulated the cellular-reduced glutathione (GSH) level and antioxidant enzyme activities. The cardioprotective action of andrographolide was found to coincide in a time-dependent manner with the up-regulation of GSH, indicating the important role of GSH. The cardioprotective action of andrographolide was also completely abolished by buthionine sulfoximine, which acts as a specific gamma-glutamate cysteine ligase (GCL) inhibitor to deplete cellular GSH level. It was subsequently found that the mRNA and protein levels of the GCL catalytic subunit (GCLC) and modifier subunit (GCLM) were up-regulated by andrographolide. Luciferase reporter assay also demonstrated that andrographolide activated both the GCLC and the GCLM promoters in the transfected rat H9C2 cardiomyocyte cell line. The 12-O-tetradecanoylphorbo-13-acetate response element or the antioxidant response element may be involved in the transactivating actions of andrographolide on the GCLC and GCLM promoters. The present study pinpoints andrographolide as a cardioprotective principle in A. paniculata and reveals its cytoprotective mechanism. PMID:18174384

  11. 41 CFR 102-33.15 - How does this part relate to the Federal Aviation Regulations?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... relate to the Federal Aviation Regulations? This part does not supersede any of the regulations in 14 CFR chapter I (Federal Aviation Regulations). ... relate to the Federal Aviation Regulations? 102-33.15 Section 102-33.15 Public Contracts and...

  12. 41 CFR 102-33.15 - How does this part relate to the Federal Aviation Regulations?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... relate to the Federal Aviation Regulations? This part does not supersede any of the regulations in 14 CFR chapter I (Federal Aviation Regulations). ... relate to the Federal Aviation Regulations? 102-33.15 Section 102-33.15 Public Contracts and...

  13. 41 CFR 102-33.15 - How does this part relate to the Federal Aviation Regulations?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... relate to the Federal Aviation Regulations? This part does not supersede any of the regulations in 14 CFR chapter I (Federal Aviation Regulations). ... relate to the Federal Aviation Regulations? 102-33.15 Section 102-33.15 Public Contracts and...

  14. 41 CFR 102-33.15 - How does this part relate to the Federal Aviation Regulations?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... relate to the Federal Aviation Regulations? This part does not supersede any of the regulations in 14 CFR chapter I (Federal Aviation Regulations). ... relate to the Federal Aviation Regulations? 102-33.15 Section 102-33.15 Public Contracts and...

  15. 41 CFR 102-33.15 - How does this part relate to the Federal Aviation Regulations?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... relate to the Federal Aviation Regulations? This part does not supersede any of the regulations in 14 CFR chapter I (Federal Aviation Regulations). ... relate to the Federal Aviation Regulations? 102-33.15 Section 102-33.15 Public Contracts and...

  16. Chapter Three - Ubiquitination and Protein Turnover of G-Protein-Coupled Receptor Kinases in GPCR Signaling and Cellular Regulation.

    PubMed

    Penela, P

    2016-01-01

    G-protein-coupled receptors (GPCRs) are responsible for regulating a wide variety of physiological processes, and distinct mechanisms for GPCR inactivation exist to guarantee correct receptor functionality. One of the widely used mechanisms is receptor phosphorylation by specific G-protein-coupled receptor kinases (GRKs), leading to uncoupling from G proteins (desensitization) and receptor internalization. GRKs and β-arrestins also participate in the assembly of receptor-associated multimolecular complexes, thus initiating alternative G-protein-independent signaling events. In addition, the abundant GRK2 kinase has diverse "effector" functions in cellular migration, proliferation, and metabolism homeostasis by means of the phosphorylation or interaction with non-GPCR partners. Altered expression of GRKs (particularly of GRK2 and GRK5) occurs during pathological conditions characterized by impaired GPCR signaling including inflammatory syndromes, cardiovascular disease, and tumor contexts. It is increasingly appreciated that different pathways governing GRK protein stability play a role in the modulation of kinase levels in normal and pathological conditions. Thus, enhanced GRK2 degradation by the proteasome pathway occurs upon GPCR stimulation, what allows cellular adaptation to chronic stimulation in a physiological setting. β-arrestins participate in this process by facilitating GRK2 phosphorylation by different kinases and by recruiting diverse E3 ubiquitin ligase to the receptor complex. Different proteolytic systems (ubiquitin-proteasome, calpains), chaperone activities and signaling pathways influence the stability of GRKs in different ways, thus endowing specificity to GPCR regulation as protein turnover of GRKs can be differentially affected. Therefore, modulation of protein stability of GRKs emerges as a versatile mechanism for feedback regulation of GPCR signaling and basic cellular processes. PMID:27378756

  17. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... 22 of this chapter, Cellular Radiotelephone systems and within the 900 MHz Business/Industrial...

  18. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800...

  19. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800...

  20. 47 CFR 90.672 - Unacceptable interference to non-cellular 800 MHz licensees from 800 MHz cellular systems or part...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Business/Industrial Land Transportation Pool. (a) Definition. Except as provided in 47 CFR 90.617(k... 900 MHz Business/Industrial Land Transportation Pool. 90.672 Section 90.672 Telecommunication FEDERAL... Procedures and Process-Unacceptable Interference § 90.672 Unacceptable interference to non-cellular 800...

  1. 31 CFR 539.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Relation of This Part to Other Laws and Regulations § 539.101...

  2. 31 CFR 539.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Relation of This Part to Other Laws and Regulations § 539.101...

  3. 31 CFR 539.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Relation of This Part to Other Laws and Regulations § 539.101...

  4. 31 CFR 539.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Relation of This Part to Other Laws and Regulations § 539.101...

  5. 31 CFR 539.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Relation of This Part to Other Laws and Regulations § 539.101...

  6. 31 CFR 576.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... or regulations. Note to § 576.101: The Iraqi Sanctions Regulations, 31 CFR part 575, have been removed from 31 CFR chapter V. ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRAQ STABILIZATION...

  7. 31 CFR 576.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... or regulations. Note to § 576.101: The Iraqi Sanctions Regulations, 31 CFR part 575, have been removed from 31 CFR chapter V. ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRAQ STABILIZATION...

  8. 31 CFR 576.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... or regulations. Note to § 576.101: The Iraqi Sanctions Regulations, 31 CFR part 575, have been removed from 31 CFR chapter V. ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRAQ STABILIZATION...

  9. 31 CFR 576.101 - Relation of this part to other laws and regulations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... or regulations. Note to § 576.101: The Iraqi Sanctions Regulations, 31 CFR part 575, have been removed from 31 CFR chapter V. ... Finance (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY IRAQ STABILIZATION...

  10. Regulation of cellular signals from nutritional molecules: a specific role for phytochemicals, beyond antioxidant activity.

    PubMed

    Virgili, Fabio; Marino, Maria

    2008-11-01

    Phytochemicals (PhC) are a ubiquitous class of plant secondary metabolites. A "recommended" human diet should warrant a high proportion of energy from fruits and vegetables, therefore providing, among other factors, a huge intake of PhC, in general considered "health promoting" by virtue of their antioxidant activity and positive modulation, either directly or indirectly, of the cellular and tissue redox balance. Diet acts through multiple pathways and the association between the consumption of specific food items and the risk of degenerative diseases is extremely complex. Recent literature suggests that molecules having a chemical structure compatible with a putative antioxidant capacity can actually "perform" activities and roles independent of such capacity, interacting with cellular functions at different levels, such as affecting enzyme activities, binding to membrane or nuclear receptors as either an elective ligand or a ligand mimic. Inductive or signaling effects may occur at concentrations much lower than that required for effective antioxidant activity. Therefore, the "antioxidant hypothesis" is to be considered in some cases an intellectual "shortcut" possibly biasing the real understanding of the molecular mechanisms underlying the beneficial effects of various classes of food items. In the past few years, many exciting new indications elucidating the mechanisms of polyphenols have been published. Here, we summarize the current knowledge of the mechanisms by which specific molecules of nutritional interest, and in particular polyphenols, play a role in cellular response and in preventing pathologies. In particular, their direct interaction with nuclear receptors and their ability to modulate the activity of key enzymes involved in cell signaling and antioxidant responses are presented and discussed. PMID:18762244